轴承中英文对照外文翻译文献

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轴承中英文对照外文翻译文献

中英文资料翻译(文档含英文原文和中文翻译)EXTENDING BEARING LIFEAbstract：Nature works hard to destroy bearings, but their chances of survival can be improved by following a few simple guidelines. Extreme neglect in a bearing leads to overheating and possibly seizure or, at worst, an explosion. But even a failed bearing leaves clues as to what went wrong. After a little detective work, action can be taken to avoid a repeat performance.Keywords: bearings failures lifeBearings fail for a number of reasons，but the most common are misapplication，contamination，improper lubricant，shipping or handling damage，and misalignment. The problem is often not difficult to diagnose because a failed bearing usually leaves telltale signs about what went wrong．However，while a postmortem yields good information，it is better to avoid the process altogether by specifying the bearing correctly in The first place．To do this，it is useful to review the manufacturers sizing guidelines and operating characteristics for the selected bearing.Equally critical is a study of requirements for noise, torque, and runout, as well as possible exposure to contaminants, hostile liquids, and temperature extremes. This can provide further clues as to whether a bearing is right for a job.1 Why bearings failAbout 40% of ball bearing failures are caused by contamination from dust, dirt, shavings, and corrosion. Contamination also causes torque and noise problems, and is often the result of improper handling or the application environment．Fortunately, a bearingfailure caused by environment or handling contamination is preventable，and a simple visual examination can easily identify the cause．Conducting a postmortem il1ustrates what to look for on a failed or failing bearing．Then，understanding the mechanism behind the failure, such as brinelling or fatigue, helps eliminate the source of the problem.Brinelling is one type of bearing failure easily avoided by proper handing and assembly. It is characterized by indentations in the bearing raceway caused by shock loading－such as when a bearing is dropped-or incorrect assembly. Brinelling usually occurs when loads exceed the material yield point(350,000 psi in SAE 52100 chrome steel)．It may also be caused by improper assembly, Which places a load across the races．Raceway dents also produce noise，vibration，and increased torque.A similar defect is a pattern of elliptical dents caused by balls vibrating between raceways while the bearing is not turning．This problem is called false brinelling. It occurs on equipment in transit or that vibrates when not in operation. In addition, debris created by false brinelling acts like an abrasive, further contaminating the bearing. Unlike brinelling, false binelling is often indicated by a reddish color from fretting corrosion in the lubricant.False brinelling is prevented by eliminating vibration sources and keeping the bearing well lubricated. Isolation pads on the equipment or a separate foundation may be required to reduce environmental vibration. Also a light preload on the bearing helps keep the balls and raceway in tight contact. Preloading also helps prevent false brinelling during transit.Seizures can be caused by a lack of internal clearance, improper lubrication, or excessive loading. Before seizing, excessive, friction and heat softens the bearing steel. Overheated bearings often change color，usually to blue-black or straw colored．Friction also causes stress in the retainer，which can break and hasten bearing failure．Premature material fatigue is caused by a high load or excessive preload．When these conditions are unavoidable，bearing life should be carefully calculated so that a maintenance scheme can be worked out．Another solution for fighting premature fatigue is changing material．When standard bearing materials，such as 440C or SAE 52100，do not guarantee sufficient life，specialty materials can be recommended. In addition，when the problem is traced back to excessive loading，a higher capacity bearing or different configuration may be used．Creep is less common than premature fatigue．In bearings．it is caused by excessive clearance between bore and shaft that allows the bore to rotate on the shaft．Creep can be expensive because it causes damage to other components in addition to the bearing．0ther more likely creep indicators are scratches，scuff marks，or discoloration to shaftand bore．To prevent creep damage，the bearing housing and shaft fittings should be visually checked．Misalignment is related to creep in that it is mounting related．If races are misaligned or cocked．The balls track in a noncircumferencial path．The problem is incorrect mounting or tolerancing，or insufficient squareness of the bearing mounting site．Misalignment of more than 1/4·can cause an early failure．Contaminated lubricant is often more difficult to detect than misalignment or creep．Contamination shows as premature wear．Solid contaminants become an abrasive in the lubricant．In addition。

毕业设计论文外文文献翻译机械设计制造及其自动化轴承的摩擦与润滑中英文对照

Friction , Lubrication of BearingIn many of the problem thus far , the student has been asked to disregard or neglect friction . A ctually , friction is present to some degree whenever two parts are in contact and move on each other. The term friction refers to the resistance of two or more parts to movement.Friction is harmful or valuable depending upon where it occurs. friction is necessary for fastening devices such as screws and rivets which depend upon friction to hold the fastener and the parts together. Belt drivers, brakes, and tires are additional applications where friction is necessary.The friction of moving parts in a machine is harmful because it reduces the mechanical advantage of the device. The heat produced by friction is lost energy because no work takes place. A lso , greater power is required to overcome the increased friction. Heat is destructive in that it causes expansion. Expansion may cause a bearing or sliding surface to fit tighter. If a great enough pressure builds up because made from low temperature materials may melt.There are three types of friction which must be overcome in moving parts: (1)starting, (2)sliding,and(3)rolling. Starting friction is the friction between two solids that tend to resist movement. When two parts are at a state of rest, the surface irregularities of both parts tend to interlock and form a wedging action. T o produce motion in these parts, the wedge-shaped peaks and valleys of the stationary surfaces must be made to slide out and over each other. The rougher the two surfaces, the greater is starting friction resulting from their movement .Since there is usually no fixed pattern between the peaks and valleys of two mating parts, the irregularities do not interlock once the parts are in motion but slide over each other. The friction of the two surfaces is known as sliding friction. A s shown in figure ,starting friction is always greater than sliding friction .Rolling friction occurs when roller devces are subjected to tremendous stress which cause the parts to change shape or deform. Under these conditions, the material in front of a roller tends to pile up and forces the object to roll slightly uphill. This changing of shape , known as deformation, causes a movement of molecules. As a result ,heat is produced from the added energy required to keep the parts turning and overcome friction.The friction caused by the wedging action of surface irregularities can be overcome partly by the precision machining of the surfaces. However, even these smooth surfaces may require the use of a substance between them to reduce the friction still more. This substance is usually a lubricant which provides a fine, thin oil film. The film keeps the surfaces apart and prevents the cohesive forces of the surfaces from coming in close contact and producing heat .Another way to reduce friction is to use different materials for the bearing surfaces and rotating parts. This explains why bronze bearings, soft alloy s, and copper and tin iolite bearings are used with both soft andhardened steel shaft. The iolite bearing is porous. Thus, when the bearing is dipped in oil, capillary action carries the oil through the spaces of the bearing. This type of bearing carries its own lubricant to the points where the pressures are the greatest.Moving parts are lubricated to reduce friction, wear, and heat. The most commonly used lubricants are oils, greases, and graphite compounds. Each lubricant serves a different purpose. The conditions under which two moving surfaces are to work determine the type of lubricant to be used and the system selected for distributing the lubricant.On slow moving parts with a minimum of pressure, an oil groove is usually sufficient to distribute the required quantity of lubricant to the surfaces moving on each other .A second common method of lubrication is the splash system in which parts moving in a reservoir of lubricant pick up sufficient oil which is then distributed to all moving parts during each cycle. This system is used in the crankcase of lawn-mower engines to lubricate the crankshaft, connecting rod ,and parts of the piston.A lubrication system commonly used in industrial plants is the pressure system. In this system, a pump on a machine carries the lubricant to all of the bearing surfaces at a constant rate and quantity.There are numerous other sy stems of lubrication and a considerable number of lubricants available for any given set of operating conditions. Modern industry pays greater attention to the use of the proper lubricants than at previous time because of the increased speeds, pressures, and operating demands placed on equipment and devices.Although one of the main purposes of lubrication is reduce friction, any substance-liquid , solid , or gaseous-capable of controlling friction and wear between sliding surfaces can be classed as a lubricant.V arieties of lubricationUnlubricated sliding. Metals that have been carefully treated to remove all foreign materials seize and weld to one another when slid together. In the absence of such a high degree of cleanliness, adsorbed gases, water vapor ,oxides, and contaminants reduce frictio9n and the tendency to seize but usually result in severe wear。

机械外文翻译---关于轴承和轴的相关知识

附录一Knowledge On The Bearings and ShaftThe bearings are fixed and reduce the load coefficient of friction in the process of mechanical transmission components. Can also say that when the other parts on the shaft relative motion, used to reduce the friction coefficient in the process of power transfer and fixed the mechanical parts to maintain the position of the shaft center. Bearings are important parts of modern machinery and equipment. Its main function is to support the mechanical rotating body to reduce the load coefficient of friction of the mechanical equipment in the transmission process. According to the different nature of friction of moving parts, bearings can be divided into two types of rolling bearings and plain bearings.Nano Lake, Italy, found a Roman vessel discovered early instance of ball bearings. The wooden ball bearings are used to support the rotating desktop. Ship construction in 40 BC. It is said that Leonardo da Vinci in the 1500 or so, a ball bearing through description. , There is a very important point is the ball collision, causing additional friction between the ball bearings of all kinds of immature factors. But can put the ball into a small cage to prevent this phenomenon. The 17th century, Galileo fixed ball ", or" cage ball "ball bearings did the earliest description. But then quite a long time, the bearings have been installed on the machine. The first patent on the ball channel the Carmarthen Philip Vaughan in 1794.In 1883, Friedrich Fischer proposed the idea of the use of suitable production machine grinding the same size, roundness accurate ball. This laid the foundation to create an independent bearing industry. In 1962, FAG the trademark has been modified and are still used today and become an integral part of the company in 1979.In 1895, Henry Timken designed the first tapered roller bearings, three years later obtained a patent and the establishment of the Timken Company.In 1907, SKF bearing factory Sven temperature Qwest designed the first modern self-aligning ball bearings.Study its role should be in terms of support, that the literal interpretation is used to bearing axis, but this is only part of its role in supporting its essence is to be able to bear the radial load. Can also be understood that it is used to a fixed axis. A fixed axis so that it can only achieverotation, and control of axial and radial movement. Motor without bearing the consequences is not work at all. Because the axis may be in any direction movement, the motor work requirements shaft only rotation. Impossible to realize the role of the drive, in theory, not only that, bearing also affect the transmission must be achieved in order to reduce this effect in the high speed shaft bearing lubrication, and some bearing lubrication, called pre-lubricated bearings, and the most of the bearing lubricant, the load at high speeds, due to the friction will not only increase energy consumption, even worse, is very easy to damage the bearing. Sliding friction into rolling friction is one-sided to say things because of the kind called plain bearings.Bearing the classification and described as follows:Equipped with a thin and long roller needle bearing (the length of the roller diameter of 3 to 10 times the diameter of generally not more than 5mm), therefore the radial structure is compact, its inner diameter and load capacity with other types of bearing the same minimum outside diameter, especially for supporting the results of radial installation dimensions restricted. needle bearing according to the use of different occasions, can be used without inner ring bearings or needle roller and cage assembly and bearing to match the journal surface directly as a bearing surface and shell holes, outer rolling surface in order to ensure the load capacity and running performance with a ring bearing the same shaft or shell holes on the raceway surface of the hardness, the machining accuracy and surface quality should be the bearing rings. use Combined needle roller bearings to the heart needle roller bearings and thrust bearing parts bearing units of the combination of its compact size, small, high precision rotation, can withstand high radial load to bear certain axial load. And the product structure in various forms, wide adaptability, easy to install. Combined needle roller bearings are widely used in machine tools, metallurgical machinery, textile machinery, printing machinery and other machinery and equipment, and make the mechanical system design is very compact and nimble.Aligning ball bearings Self-aligning ball bearings: two of the inner ring raceway and the raceway between the spherical outer ring, the assembly of the drum-shaped roller bearing. The outer ring raceway curvature center and bearing center line, and therefore have the same aligning and self-aligning ball bearings. Axis, the shell deflection occurs, you can automatically adjust to not increase the burden of bearing. Spherical roller bearings can bear radial load and axial load in two directions. Aligning ball bearing radial load capacity, suitable for a heavy impact loadconditions. The inner diameter is tapered bore bearings can be installed directly. Or use the adapter sleeve, remove the tube installed in the cylinder axis. Cage the use of steel stamping cage, forming polyamide-aligning ball bearings withstand heavy loads and impact loads, precision instruments, low noise motors, automobiles, motorcycles, metallurgy, mill, mining, petroleum, paper, cement, pressed sugar industry and the general machinery.Deep groove ball bearings imported bearings are mainly used for pure radial load, both radial and axial load. Only under pure radial load, the contact angle is zero. Performance of angular contact bearings, deep groove ball bearings with a larger radial clearance, and is subjected to high axial load. Deep groove ball bearings, the friction coefficient is small, the limit speed is also high, especially in a large high-speed operation of the axial load conditions, deep groove ball bearings Thrust ball bearings are more advantages. Deep groove ball bearings are the most representative of the rolling bearings, widely used. For high speed or high speed operation, and is very durable, without regular maintenance. The class has a small coefficient of friction, high limiting speed, simple structure, low manufacturing cost, easy to achieve high manufacturing precision. Size range and diversity, changes in the form used in precision instruments, low noise motors, automobiles, motorcycles and general machinery and other industries, is the machinery industry's most widely used type of bearings. The main radial load, and can withstand a certain amount of axial load deep groove ball bearings can be used for the transmission, instrumentation, motors, appliances, internal combustion engines, transportation vehicles, agricultural machinery, construction machinery, construction machinery and so on.Aligning roller bearing is a spherical outer ring between the two raceways of the inner ring raceway assembly with drum-shaped roller bearings. Aligning roller bearing with two rollers, mainly exposed to the diameter of a load, but also able to withstand the axial load in either direction. High radial load capacity, especially suitable for work overload or vibration loads, but can not afford the pure axial load. This kind of bearing outer ring raceway is spherical shape, aligning performance is good, can compensate concentricity error. Spherical roller bearings have two symmetrical spherical roller outer ring of a common spherical raceway, two bearing axis of inner ring tilt angle of the raceway, has a good aligning properties, when the axis force bearing when bending or install a different heart to continue its normal use, tune concentric with the bearing dimension series vary, generally allow aligning angle of 2.5 degrees, the type of loadbearing capacity, in addition to radial loads The outer bearings can withstand axial load of the two-way role, with good impact resistance, in general, self-aligning roller bearings allowed speed is low. Spherical roller bearings according to the section shape of the roller is divided into two different structures of the symmetrical spherical roller and non-symmetrical spherical roller, asymmetric self-aligning roller bearings are early products, mainly the host repair services, new design host rarely use symmetrical self-aligning roller bearings, the internal structure of the overall improvement of the design and parameters optimization, than with the early production of aligning roller bearings, able to withstand greater axial load, this bearing run lower temperatures, it can adapt to the requirements of high speed, according to whether the inner rib and cage can be divided into two kinds of C and CA, C-type bearing is characterized by the inner wall and the use of steel stamping frame, the CA-bearing characteristics for the inner ring on both sides have ribs machined solid cage in order to improve the lubrication, can provide users with the outer ring with a circular tank, and three hole Spherical roller bearings, set the code to the bearings / W33 can also supply according to the requirements of users with the inner hole of the aligning roller bearings, in order to facilitate customer handling and replacement of bearings, can also be provided within the hole with a taper aligning roller bearings, bearings, tapered bore, taper 1:12 after the set, code-named K, in order to adapt to specific user requirements can also be provided within the taper bearings of 1:30, followed by the set, code-named K30 hole with The taper of the bearing can be used locknut bearing mounted on the conical journal, but also can make use of the adapter sleeve or withdrawal sleeve bearings installed in the cylindrical journal.Combination of bearing: a bearing formed by the combination of bearing structure in the above-mentioned two or more of rolling bearings. Such as needle roller and cylindrical roller thrust bearings, needle roller and thrust ball bearings, needle roller and angular contact ball bearings, etc..Bearing life: under certain loads, the bearings in the number of revolutions or hours before pitting experienced, known as the bearing life.The life of rolling bearings of the number of revolutions (or number of hours worked under a certain speed) is defined: In this life within the bearing, any bearing ring or rolling body on the initial fatigue damage (spalling or defect). But both in the laboratory tests or in actual use, can clearly see the appearance of the same bearing in the same working conditions, to differ materiallyfrom actual life. In addition to the bearing of several different definitions of "life", one of the so-called "working life", it means that the actual life of a bearing can be achieved before the damage from the wear and tear, damage is usually not caused by fatigue, but caused by wear and tear, corrosion, seal damage.Due to differences in manufacturing precision, material uniformity, even if the same material, bearing the same batch of the same size, in the same working conditions, their longevity is not the same. In terms of statistical life is 1 unit relative life expectancy of up to four units, the shortest was 0.1 to 0.2 units, the ratio of the longest and shortest life of 20 to 40 times.The installation of bearings:Bearing installation, good or bad, will affect the accuracy, bearing life and performance. , The installation of the bearing, in accordance with the operating standards include the following items, including the bearing installation.①cleaning bearings and related parts have been greased bearings and bilateral withseals or dust cover, no need to clean before the installation of the ring bearing.② Check the size and finishing conditions of the relevant parts of the③installation method bearing installation should be based on the nature of the bearing structure, size, and bearing components with pressure should be directly added to a tight fit to the ferrule end surface, may not pass the pressure of the rolling element bearing installation generally use the following method: a press-fit bearing inner ring and shaft so tight fit, the outer ring and the bearing hole is loose with the available presses will be bearing the first pressure mounted on the shaft and the shaft together with the bearing with load bearing hole press-fit bearing inner ring side surface, pad assembly sleeve of a soft metal material (copper or mild steel), the assembly casing diameter should be slightly larger than the journal diameter, the diameter of the outer diameter than the bearing inner ring ribs slightly smaller, in order to avoid pressure in the cage. The bearing outer ring and the bearing hole is a tight fit, the inner ring and the shaft is loose with the bearing first pressed into the bearing hole, this time the assembly casing outside diameter should be slightly smaller than the diameter of the bore. If the bearing ring and shaft and housing bore are a tight fit to install the indoor ring and outer ring to be pressed into the shaft and housing bore, the assembly structure of the casing should be able to charge tight end face of the bearing inner and outer rings. (b) heating with heated bearings or bearing, the use of thermal expansionwill be a tight fit to change the installation method for a loose fit.④ bearing installation inspection⑤lubricant added to the installation of high-speed precision angular contact ball bearings, mainly for the load lighter, high-speed rotating occasions, the requirement of bearing high-precision, high speed, low temperature rise Low vibration and service life of high-speed precision angular contact ball bearings. Often for high-speed electric spindle bearing installed in pairs, the key component parts of the inner surface of the grinding machine of high speed electric spindle. The main technical indicators: 1. Bearing accuracy specifications: more than GB/307.1-94 the P4 level precision high-speed performance: dmN value of 1.3 ~ 1.8x 106 / min 3. Life (average):> 1500 hLife of high-speed precision angular contact ball bearings have a great relationship with the installation, you should note the following: ①The bearings shall be installed in a clean, clean room, bearing carefully matching, bearing spacers to go through grinding, maintaining the premise of high-inside and outside the ring spacers, spacer parallelism should be controlled in 1um following; ②The bearings prior to installation should be clean, cleaning inner slopes upward, should be flexible and feel no sense of stagnation, dried and put into the specified amount of grease, in the case of oil mist lubrication should be placed in a small amount of oil mist oil; ③bearing installation should be used specialized tools, even by force, strictly prohibited beating; ④The bearings shall be stored in clean air, corrosive gases, relative humidity of not more than 65 % long-term storage should be periodically rust-proof.Tapered roller bearings, water pump bearing installation:①the installation of bearings: bearing must be installed in a dry, clean environment conditions. Before installation, carefully check the mating surface of the shaft and shell, the face of the convex shoulder trench and connection quality of surface processing. All match the connected surface must be carefully cleaned and remove the burrs, casting raw surface must be in addition to net sand. Bearing installation should be preceded by cleaning with gasoline or kerosene, clean and dry before use, and to ensure good lubrication, bearings are commonly used grease lubrication, oil lubrication can be used. With grease lubrication should be used free of impurities, anti-oxidation, rust and extreme pressure performance superior grease. The grease filling is 30% to 60% of the bearings and the bearing capacity of the container, not too much. Withsealing structure of the double row tapered roller bearings and pump shaft bearing filled a good grease, users can directly use, not for cleaning. Bearing installation, you must exert equal pressure on the circumference of the ferrule end face pressed into the ring not want first-class tools to tap the bearing face, so as not to damage the bearing. Small amount of interference with the sleeve at room temperature, press and hold the bearing ring face hammer to beat the sleeve through the sleeve rings evenly pressed into. If large quantities of installation can be a hydraulic press.②bearing removal: Remove the bearing intend to continue to use, you should use the appropriate removal tool. The demolition of the interference fit of the ring, only to increase the tension in the ring, never to allow demolition of the rolling elements, or the rolling element and raceway will be crushed.③bearing use of the environment: the use of location and conditions of use and environmental conditions to select the specifications of size, accuracy, and with the right bearing is the premise to ensure that the bearing life and reliability. Parts: tapered roller bearings are suitable to withstand the radial load mainly radial and axial joint load, usually paired to two sets of bearings used primarily in the car's front and rear wheel hub, active bevel gear, differential, reducer and transmission parts. Allowable speed: correctly installed, well-oiled environment, allowing the bearing limit speed of 0.3 to 0.5 times. Under normal circumstances, the limit of 0.2 times the speed of the most suitable. Allow the angle of inclination: tapered roller bearings are generally not allowed axis of the relative shell hole tilt, where tilt maximum of not more than 2 '. Allow the temperature: under the normal load, the lubricant has high temperature resistance, and adequate lubrication conditions, the general bearing allows to work in -30 ° C to 150 ° C ambient temperature.Axis function and type:Axis is one of the important parts in the machine, used to support the rotating parts of machinery.Depending on the load bearing axis can be divided into the shaft, drive shaft and spindle three kinds. Shaft only transfer torque to withstand bending moments, such as the gear reducer shaft; drive shaft transmitting torque only not withstand the bending moment or bending moment is small. Such as automotive drive shaft; spindle is exposed only to the moment rather than transmit torque, such as the axis of the rail vehicle, the front axle of the bicycle.The shape of the shaft axis can be divided into: straight axle, crankshaft and flexible wire axis. Crankshaft is commonly used in reciprocating machinery. The flexible wire shaft wire layers close together by layers of flexible torque and rotational movement spread to any location commonly used in vibrators and other devices. This chapter only study the direct axis.Shaft design, manufacturing process according to job requirements and to consider other factors, the appropriate choice of materials, structural design, through strength and stiffness, set the axis of the structure shape and size, if necessary, consider the vibration stability.Axis of the commonly used materials:The axis of the material is often used carbon steel and alloy steel.Carbon steel bearing 35,45,50 high-quality carbon structural steel has higher mechanical properties, more applications, of which the most widely used steel 45. In order to improve its mechanical properties, normalizing or quenching and tempering treatment. Unimportant, or by a smaller force axis, can be used such as Q235, Q275 carbon structural steel.Alloy steel alloy steel has higher mechanical properties, but the price is more expensive, used for special requirements of the shaft. For example: the sliding bearings of high-speed shaft, commonly used in 20Cr, 20CrMnTi low-carbon alloy structural steel after carburizing can improve the wear resistance of the journal; generator rotor shaft in the high temperature, high-speed and overload conditions. must have good high temperature mechanical properties, often to adopt 40CrNi, 38CrMoAlA alloy structural steel. It is worth noting: the type and heat treatment of steel, its elastic modulus is very small. For use of alloy steel or heat treatment to improve the shaft stiffness is no practical results. In addition, the alloy steel higher sensitivity to stress concentration, alloy steel shaft design, more should be structured to avoid or reduce the stress concentration and reduce the surface roughness.Axis rough general round bar or forgings, and sometimes can be cast or ductile iron. For example, made of nodular cast iron crankshaft, camshaft, low cost, better vibration absorption, low sensitivity to stress concentration, good strength, etc..Axis of structural design:The axis of the structure design is to make each part of the axis has a reasonable shape and size. Its main requirements are: 1) axis should be easy processing. Parts of the shaft to be easy disassembly (manufacture and installation requirements); 2) axis and the shaft parts have accurateposition (location); 3) parts to firmly and reliably and relatively fixed (fixed); 4) to improve the force situation, reducing the stress concentration.①The manufacturing installation requirementsIn order to facilitate the assembly and disassembly of the shaft parts, often the shaft made of the ladder. Split the box in the shaft, its diameter from the shaft end and gradually increases toward the middle. As shown above, can turn the gear, the sleeve, the left end bearings, bearing caps and pulley from the axis of the left end assembly and disassembly, and another from the right end of the assembly and disassembly of rolling bearings. Shaft parts is easy to install, should chamfer of the shaft end and the end of the shaft section.Axis grinding shaft section should wheel the more process slots; car threaded shaft section should be undercut.Meet the requirements of the case, the axis of the shape and size should be simple in order to facilitate processing.②The axis positioning of partsLadder shaft cross-section changes a place called the shaft shoulder, since the axial positioning of the role. Shaft shoulder makes gear positioned on the shaft; shaft shoulder pulley positioning; shaft shoulder to the right end of the rolling bearing positioning.Some parts rely on a set of simple positioning, such as above the left end of rolling bearings.③The axis parts of the fixedAxial fixation of the shaft parts, often with the shaft shoulder, sleeve, nut or shaft end of the retaining ring (also known as the plate) and other forms. Gear to achieve the axial two-way fixed. Gear by the axial force, right through the shaft shoulder, by the axis and shoulders in the rolling bearing inner ring; left sleeve top in the rolling bearing inner ring. Can not use the sleeve or sleeves too long, we can use the round nut to be fixed. Pulley axial fixed retaining ring depend on the shaft shoulder and the shaft end.Axis intensity calculated as follows:Axis intensity shall be calculated according to the shaft bearing, using the appropriate method of calculation. The common axis strength calculation method has the following two:① Press the torsional strength calculationThis method applies only to withstand the torque of the drive shaft of accurate calculation, iswell received by the bending moment and torque axis approximate calculation can also be used. Circular section shaft transmitting torque only, the strength condition.Withstand both pass to turn short axis of the bending moment can also be used on the preliminary estimate of the diameter of the design formula:In addition, the empirical formula can be used to estimate the diameter of the shaft. For example, in the general reducer, high-speed input shaft diameter according to its associated motor shaft diameter D estimates, d = (0.8 ~ 1. 2) D; all levels of low-speed shaft of the gear center distance on the shaft diameter according to the same level a estimates, d = (0.3 0.4) a.② According to the synthetic strength of the bending and torsionSingle-stage cylindrical gear reducer design sketches, each symbol indicates the length of the Dimensions. Obviously, when the parts laid out on the sketch, the role of location of the external load and support reaction force can be determined. Thus can be used for mechanical analysis of the shaft and draw the bending moment diagram and torque diagram. Then you can press the synthetic strength of the bending and torsion shaft diameter.For the cross-section of the keyway should be calculated shaft diameter increased by about 4%. Calculated shaft diameter greater than the shaft diameter of preliminary estimates of the structural design, that the strength of the chart axis is not enough, you must modify the structural design; calculated shaft diameter less than the estimates of the structural design of shaft diameter, and the difference is not very generally subject to the structural design of the shaft diameter.For general-purpose shaft designed by the above method can. Important axis, yet further strength check (such as the safety factor method), the calculation method available at the reference.Shaft stiffness calculated as follows:Axis by the bending moment will produce a bending torque role will have the torsional deformation. If the shaft stiffness is not enough, it will affect the normal work of the axis. For example, the deflection of the rotor shaft is too large, will change the rotor and stator gap and affect the performance of the motor. Another example is the rigidity of the machine spindle is enough, it will affect the machining accuracy. Therefore, in order so that the axis is not enough stiffness and failure, must be designed to limit their working conditions under the shaft deformationAxis of the concept of critical speed:Uneven due to structural asymmetries of the rotary parts, materials, processing errors and other reasons, to make the rotation center of gravity is precisely located in the geometric axis, it is almost impossible. In fact, the center of gravity and the geometric axis generally total a slight eccentricity, and thus the centrifugal force generated when rotating the axis by the interference of cyclical loading.Axis suffered external frequency axis since the vibration frequency of the same operation will be unstable vibration occurs, a phenomenon known as the resonance of the shaft. Resonance when the shaft speed is called the critical speed. If the shaft speed is stuck near the critical speed, the axis of deformation increases rapidly, as well as the axis, the extent of the damage or even the whole machine. Therefore, the important, especially high-speed axis to calculate the critical speed, and shaft speed n to avoid the critical speed nc.The shaft critical speed, the lowest one called the first critical speed, the remaining second, third ......Speed is below a first critical speed axis is called the rigid shaft; more than the first critical speed axis is called the flexible shaft.Slender axis machining process characteristics:(1) slender shaft turning the process characteristicsSlender shaft rigidity is poor, turning fashion folder properly, it is easy because of the role of cutting force and gravity bending deformation,Vibration, thus affecting the machining accuracy and surface roughness.The slender shaft of the thermal diffusivity of poor performance, the effect of cutting heat, will produce quite a large linear expansion. If the two ends of the shaft to a fixed support, the workpiece due to the elongation of the top bend.The longer axis, a walk the knife for a long time, tool wear, thus affecting the geometry of the precision of the parts.Car slender shaft supporting the workpiece with the tool holder, the two supporting block inappropriate parts pressure will affect the machining accuracy. If the pressure is too small or do not touch, it does not work, you can not improve the stiffness of the parts; if the pressure is too large, the parts are pressed to the lathe tool, the cutting depth increases, the car out of the diameter is small, continue to move with the turret bearing block support in the small-diameter cylindrical。

轴承的中英文对照

lower half bearing轴承下瓦lubed-for-life bearing永久润滑轴承(即橡胶轴承)lubri-seal bearing阻油环轴承magnetic bearing磁向位,磁方位magnetic thrust bearing磁性推力轴承main bearing主轴承main rod bearing主杆轴承mainshaft bearing主轴轴承maintenance-free bearing自润滑轴承mechanical bearing轴承(总称)midship shaft bearing中间轴轴承miniature bearing微型轴承,超小型轴承molded-fabric bearing(设计)模制纤维轴承motor support bearing电动机支承轴承movable bearing活动支承multi-roll bearing滚针轴承multirow bearing多列轴承multipart bearing弓形轴承,扇形轴承multiple-groove bearing多油槽轴承neck bearing中间轴承needle bearing滚针轴承needle(type) roller bearing滚针轴承noise-free bearing低噪声轴承nonfilling slot type bearing无滚珠槽的滚动轴承non-locating bearing浮动轴承,不定位轴承non-porous bearing无孔轴承oil film bearing油膜轴承oil flooded bearing油膜轴承,液体摩擦轴承oil-bath type bearing油浴润滑式轴承oilless bearing不加油轴承自动润滑轴承石墨润滑轴承，含油轴承oil-retaining bearing含油轴承open spindle bearing开式锭子轴承oscillating bearing关节轴承oscillating journal bearing摆动轴径轴承outboard bearing外置轴承parallel bearing滑动轴承parallel-roller bearing平行滚柱轴承partial bearing半轴承partial journal bearing半围轴承(轴瓦在180°范围内包围着轴颈的滑动轴承) pedestal bearing支承轴承pendulum bearing钟摆轴承pin rocker bearing铰接支座,圆柱枢轴摆动轴承pinion bearing小齿轮轴承piston pin bearing活塞销轴承轴承的中英文对照（三）2007-03-05 16:39gyro bearing旋转方位,陀螺仪方位,回转器方向half-and-haif bearing半轴承无盖轴承hanging bearing吊挂轴承hardwood bearing硬木轴承head bearing止端轴承heavy-duty bearing重载轴承hydrodynamic journal bearing液体动压轴承,油膜轴承hydrostatic bearing静压轴承idler shaft bearing空转轴轴承inclined bearing(倾)斜轴承,斜支承inner bearing内轴承intermediate bearing中间轴承jack shaft bearing曲柄轴轴承jewelled bearing宝石轴承Jordan bearing推力套筒轴承journal bearing经向轴承kick-starter bearing冲式起动器的曲柄轴承kingpin bearing凸轮止推回转轴承,止推销轴承,止推枢轴承,中心(转向节)轴承knife-edge bearing刃形支承,刃支承,刀口承knuckle bearing铰式支座,球形支座,关节轴承labyrinth bearing迷宫轴承,曲径式密封轴承laminated bearing夹布胶木轴承,层压轴承leading -screw bearing传动螺杆轴承lignumvitae bearing层压胶木轴承load bearing承载,承重locating bearing止推轴承,定位轴承lock nut bearing锁紧螺帽座longitudinal wall hanger bearing墙托架轴承long-path bearing远距离方位lower bearing下轴承lower half bearing轴承下瓦lubed-for-life bearing永久润滑轴承(即橡胶轴承)lubri-seal bearing阻油环轴承magnetic bearing磁向位,磁方位magnetic thrust bearing磁性推力轴承main bearing主轴承main rod bearing主杆轴承mainshaft bearing主轴轴承maintenance-free bearing自润滑轴承mechanical bearing轴承(总称)midship shaft bearing中间轴轴承miniature bearing微型轴承,超小型轴承molded-fabric bearing(设计)模制纤维轴承motor support bearing电动机支承轴承movable bearing活动支承multi-roll bearing滚针轴承multirow bearing多列轴承multipart bearing弓形轴承,扇形轴承multiple-groove bearing多油槽轴承neck bearing中间轴承needle bearing滚针轴承needle(type) roller bearing滚针轴承noise-free bearing低噪声轴承nonfilling slot type bearing无滚珠槽的滚动轴承non-locating bearing浮动轴承,不定位轴承non-porous bearing无孔轴承oil film bearing油膜轴承oil flooded bearing油膜轴承,液体摩擦轴承oil-bath type bearing油浴润滑式轴承oilless bearing不加油轴承自动润滑轴承石墨润滑轴承，含油轴承oil-retaining bearing含油轴承open spindle bearing开式锭子轴承oscillating bearing关节轴承oscillating journal bearing摆动轴径轴承outboard bearing外置轴承parallel bearing滑动轴承parallel-roller bearing平行滚柱轴承partial bearing半轴承partial journal bearing半围轴承(轴瓦在180°范围内包围着轴颈的滑动轴承) pedestal bearing支承轴承pendulum bearing钟摆轴承pin rocker bearing铰接支座,圆柱枢轴摆动轴承pinion bearing小齿轮轴承piston pin bearing活塞销轴承pivot bearing枢轴承,摆动支座,中心(轴尖)支承,立式止推轴承plain-and -ball bearing滑动与滚动组合轴承plane bearing平面轴承plummer block bearing架座,止推轴承pneumatic bearing空气轴承pocket bearing油盘轴承porous bearing多孔轴承powdiron bearing多孔铁轴承,粉未铁轴承power take-off lever bearing动力输出轴轴承preloaded bearing预紧轴承prelubricated bearing预(加)润滑[油密封]轴承,一次润滑轴承pressure-feed air bearing静压空气轴承pressure-loaded bearing承压轴承proper bearing紧密接触轴承盖世汽车社区。

机械专业毕业论文外文翻译--实验研究激光加工表面微观造型平行的推力轴承

附录一英文科技文献翻译英文原文：Experimental investigation of laser surface textured parallel thrustbearingsPerformance enhancements by laser surface texturing (LST) of parallel-thrust bearings is experimentally investigated. Testresults are compared with a theoretical model and good correlation is found over the relevant operating conditions. A compari-son of the performance of unidirectional and bi-directional partial-LST bearings with that of a baseline, untextured bearing ispresented showing the beneﬁts of LST in terms of increased clearance and reduced friction.KEY WORDS: ﬂuid ﬁlm bearings, slider bearings, surface texturing1. IntroductionThe classical theory of hydrodynamic lubricationyields linear (Couette) velocity distribution with zeropressure gradients between smooth parallel surfacesunder steady-state sliding. This results in an unstablehydrodynamic ﬁlm that would collapse under anyexternal force acting normal to the surfaces. However,experience shows that stable lubricating ﬁlms candevelop between parallel sliding surfaces, generally because of some mechanism that relaxes one or moreof the assumptions of the classical theory.A stable ﬂuid ﬁlm with suﬃcient load-carryingcapacity in parallel sliding surfacescan be obtained,for example, with macro or micro surface structure ofdiﬀerent types. These include waviness [1] and protruding microasperities [2–4]. A good literature review onthe subject can be found in Ref. [5]. More recently,laser surface texturing (LST) [6–8], as well as inletroughening by longitudinal or transverse grooves [9]were suggested to provide load capacity in parallelsliding. The inlet roughness concept of Tonder [9] isbased on ……eﬀective clearance‟‟ reduction in the s lidingdirection and in this respect it is identical to the par-tial-LST concept described in ref.[10] for generatinghydrostatic eﬀect in high-pressure mechanical seals.Very recently Wang et al. [11] demonstrated experimentally a doubling of the load-carrying capacity forthe surface- texture design by reactive ion etching ofSiC parallel-thrust bearings sliding in water. Thesesimple parallel thrust bearings are usually found inseal-less pumps where the pumped ﬂuid is used as thelubricant for the bearings. Due to the parallel slidingtheir performance is poorer than more sophisticatedtapered or stepped bearings. Brizmer et al. [12] demon-stratedthepotential of laser surface texturing in theform of regular micro-dimples for providing load-carrying capacity with parallel-thrust bearings. A model of a textured parallel slider was developed and the eﬀect of surface texturing on load-carrying capacitywas analyzed. The optimum parameters of the dimples were found in order to obtain maximum load-carrying capacity. A micro-dimple ……collective eﬀect‟‟ was identi-ﬁed that is capable of generating substantial load-carrying capacity, approaching that of optimumconventional thrust bearings. The purpose of the present paper is to investigate experimentally the validity of the model described in Ref. [12] by testing practical thrust bearings and comparing the performance of LST bearings with that of the theoretical predictions and with the performance of standard non-textured bearings2. BackgroundA cross section of the basic model that was analyzedin Ref. [12] is shown in figure1. A slider having awidth B is partially textured over a portion Bp =αB ofits width.The textured surface consists of multipledimples with a diameter，depth and area densitySp. As a result of the hydrodynamic pressure generatedby the dimples thesliding surfaces will be separated bya clearance depending on the sliding velocity U, theﬂuid viscosity l and the external load It was foundin Ref. [12] that an optimum ratio exists for the parameter that provides maximum dimensionlessload-carrying capacity where L isthe bearing length, and this optimum value is hp=1.25. It was further found in Ref. [12] that an optimumvalue exists for the textured portion a depending onthe bearing aspect ratio L/B. This behavior is shown inﬁgure 2 for a bearing with L/B = 0.75 at various values of the area density Sp. As can be seen in the rangeof Sp values from0.18 to 0.72 the optimum a valuevaries from 0.7 to 0.55, respectively. It can also be seenfrom ﬁgure 2 that for a < 0.85 no optimum valueexists for Sp and the maximum load W increases withincreasing Sp. Hence, the largest area density that canbe practically obtained with the laser texturing isdesired. It is also interesting to note from ﬁgure 2 theadvantage of part ial-LST (a < 1) over the full LST(a = 1) forbearing applications. At Sp= 0.5, forexample, the load W at a = 0.6 is about three timeshigher than its value at a = 1. A full account of thisbehavior is given in Ref. [12].3. ExperimentalThe tested bearings consist of sintered SiC disks10 mm thick, having 85 mm outer diameter and40 mm inner diameter. Each bearing (see ﬁgure 3)comprises a ﬂat rotor (a) and a six-pad stator (b). Thebearings were provided with an original surface ﬁnish by lapping to a roughness average Ra= 0.03 lm. Eachpad has an aspect ratio of 0.75 when its width is measured along the mean diameter of the stator. The photographs of two partial-LST stators are shown inﬁgure 4 where the textured areas appear as brightermatt surfaces. The ﬁrst stato r indicated (a) is a unidirectional bearing with the partial-LST adjacent to theleading edge of each pad, similar to the model showninﬁgure 1. The second stator (b) is a bi-directionalversion of a partial-LST bearing having two equal textured portions, a/2, on each of the pad ends. The lasertexturing parameters were the following; dimple depth, dimplediameter and dimple area density Sp= 0.60.03. These dimpledimensions were obtained with 4 pulses of 30 ns duration and 4 mJ each using a 5 kHz pulsating Nd:YAGlaser. The textured portion of the unidirectional bearing was a= 0.73 and that of the bi-directional bearingwas a= 0.63. As can be seen from ﬁgure 2 both thesea values should produce load-carrying capacity varyclose to the maximum theoretical value.The test rig is shown schematically in ﬁgure 5. An electrical motor turns a spindle to which an upperholder of the rotor is attached. A second lower holderof the stator is ﬁxed to a housing, which rests on ajournal bearing and an axial loading mechanism that can freely move in the axial direction. An arm thatpresses against a load cell and thereby permits frictiontorque measurements prevents the free rotation of thishousing. Axial loading is provided by means of deadweights on a lever and is measured with a second loadcell. A proximity probe that is attached to the lowerholder of the stator allows on-line measurements ofthe clearance change between rotor and stator as thehydrodynamic eﬀects causeaxial movement of thehousing to which the stator holder is ﬁxed. Tap wateris supplied by gravity from a large tank to the centerof the bearing and the leakage from the bearing is collected and re-circulated. A thermocouple adjacent tothe outer diameter of the bearing allows monitoring ofthe water temperature as the water exit the bearing. APC is used to collect and process data on-line. Hence,the instantaneous clearance, friction coeﬃcient, bearing speed and exit water temperature can be monitoredconstantly.The test protocol includes identifying a reference“zero” point for the clearance measurements by ﬁrstloading and then unloading a stationary bearing overthe full load range. Then the lowest axial load isapplied, the water supply valve is opened and themotor turned on. Axial loading is increased by stepsof 40 N and each load step is maintained for 5 minfollowing the stabilization of the friction coeﬃcient ata steady-state value. The bearing speed and water temperature are monitored throughout the test for anyirregularities. The test ends when a maximum axialload of 460 N is reached or if the friction coeﬃcientexceeds a value of 0.35. At the end of the last loadstep the motor and water supply are turned oﬀandthe reference for the clearance measurements isrechecked. Tests are performed at two speeds of 1500and 3000 rpm corresponding to average sliding velocities of 4.9 and 9.8 m/s, respectively and each test isrepeated at least three times.4. Results and discussionAs a ﬁrst step the validity of the theoretical modelin Ref. [12] was examined by comparing the theoretical and experimental results of bearing clearance versus bearing load for a unidirectional partial-LSTbearing. The results are shown in ﬁgure 6 for the twospeeds of 1500 and 3000 rpm where the solid anddashed lines correspond to the model and experiment,respectively. As can be seen, the agreement betweenthe model and the experiment is good, with diﬀerences of less than 10%, as long as the load is above150 N. At lower loads the measured experimentalclearances are much larger than the model predictions, particularly at the higher speed of 3000 rpmwhere at 120 N the measured clearance is 20 lm,which is about 60% higher than the predicted value.It turns out that the combination of such large clearances and relatively low viscosity of the water mayresult in turbulent ﬂuid ﬁlm. Hence, the assumptionof laminar ﬂow on which the solution of the Reynolds equation in Ref. [12] is based may be violatedmaking the model invalid especially at the higherspeed and lowest load. In order to be consistent withthe model of Ref. [12] it was decided to limit furthercomparisons to loads above 150 N.It should be noted here that the ﬁrst attempts to testthe baseline untextured bearing with the original surface ﬁnish of Ra= 0.03 lm on both the stator androtor failed due to extremely high friction even at thelower loads. On the other hand the partial-LST bearingran smoothly throughout the load range. It was foundthat the post-LST lapping to completely remove about2 lm height bulges, which are formed during texturingaround the rims of the dimples, resulted in a slightlyrougher surface with Ra= 0.04 lm. Hence, the baselineuntextured stator was also lapped to the same rough- ness of the partial-LST stator and all subsequent testswere performed with the same Ra value of 0.04 lm forall the tested stators. The rotor surface roughness remained, the original one namely, 0.03 lm. Figure 7presents the experimental resultsfor the clearance as afunction of the load for a partial-LST unidirectionalbearing (see stator in ﬁgure 4(a)) and a ba selineuntextured bearing. The comparison is made at the twospeeds of 1500 and 3000 rpm. The area density of thedimples in the partial-LST bearing is Sp= 0.6 and thetextured portion is a ¼ 0:734. The load range extendsfrom 160 to 460 N. The upper load was determined bythe test-rig limitation that did not permit higher loading. It is clear from ﬁgure 7 that the partial-LST bearing operates at substantially larger clearances than theuntextured bearing. At the maximum load of 460 Nand speed of 1500 rpm the partial-LST bearing has aclearance of 6 lm while the untextured bearing clearance is only 1.7 lm. At 3000 rpm the clearances are 6.6and 2.2 lm for the LST and untextured bearings,respectively. As can be seen from ﬁgure 7 this ratio ofabout 3 in favor of the partial-LST bearing is maintained over the entire load range.Figure 8 presents the results for the bi-directionalbearing (see stator in ﬁgure 4(b)). In this case the LSTparameters are Sp ¼ 0:614 and a ¼ 0:633. The clearances of the bi-directional partial-LST bearing arelower compared to these of the unidirectional bearingat the same load. At 460 N load the clearance for the1500 rpm is 4.1 lm and for the 3000 rpm it is 6 lm.These values represent a reduction of clearance between 33 and 10% compared to the unidirectional case. However, as can be seen from ﬁgure 8 the performance ofthe partial-LST bi-directional bearing is still substantially better than that of the untextured bearing.The friction coeﬃcient of partial-LST unidirectionaland bi-directional bearings was compared with that ofthe untextured bearing in ﬁgures 9 and 10 for the twospeeds of 1500 and 3000 rpm, respectively. As can beseen the friction coeﬃcient of the two partial-LSTbearings is very similar with slightly lower values inthe case of the more eﬃcient unidirectional bearing.The friction coeﬃcient of the untextured bearing is much larger compared to that of the LST bearings. At1500 rpm (ﬁgure 9) and the highest load of 460 N thefriction coeﬃcient of the untextured bearing is about0.025 compared to about 0.01 for the LST bearings.At the lowest load of 160 N the values are about 0.06for the untextured bearing and around 0.02 for theLST bearings. Hence, the friction values of the untextured bearing are between 2.5 and 3 times higher thanthe corresponding values for the partial-LST bearingsover the entire load range. Similar results wereobtained at the velocity of 3000 rpm (ﬁgure 10) butthe level of the friction coeﬃcients is somewhat higherdue to the higher speed. The much higher friction ofthe untextured bearing is due to the much smallerclearances of this bearing (see ﬁgures 7 and 8) thatresult in higher viscous shear.5. ConclusionThe idea of partial-LST to enhance performance ofthe parallel thrust bearing was evaluated experimentally.Good correlation was found with a theoretical model as long as the basic assumption of laminar ﬂow in the ﬂuidﬁlm is valid. At low loads with relatively large clearances, where turbulence may occur, the experimental clearance is larger than the prediction of the model.The performance of both unidirectional and bidirectional partial-LST bearings in terms of clearanceand friction coeﬃcient was compared with that of abaseline untextured bearing over a load range in whichthe theoretical model is valid. A dramatic increase, ofabout three times, in the clearance of the partial-LSTbearings compared to that of the untextured bearingwas obtained over the entire load range. Consequentlythe friction coeﬃcient of the partial-LST bearings ismuch lower, representing more than 50% reduction infriction compared to the untextured bearing.The larger clearance and lower friction make thepartial-LST simple parallel thrust bearing conceptmuch more reliable and eﬃcient especially in seal-lesspumps and similar applicatio ns where the processﬂuid, which is often a poor lubricant, is the only available lubricant for the bearings.AcknowledgmentsThe authors would like to thank Mr. J. Boylan ofMorgan AM&T for providing the bearing specimensand Mr. N. Barazani of Surface Technologies Ltd. Forproviding the laser surface texturing.实验研究激光加工表面微观造型平行的推力轴承实验是研究激光处理的表面微观造型平行的推力轴承增强的某些性能。

轴承外文翻译

BEARING LIFE ANALYSISABSTRACTNature works hard to destroy bearings, but their chances of survival can be improved by following a few simple guidelines. Extreme neglect in a bearing leads to overheating and possibly seizure or, at worst, an explosion. But even a failed bearing leaves clues as to what went wrong. After a little detective work, action can be taken to avoid a repeat performance.1 .WHY BEARINGS FAILAn individual bearing may fail for several reasons; however, the results of an endurance tes t series are only meaningful when the test bearings fail by fatigue-related mechanisms. The experimenter must control the test process to ensure that this occurs. Some of the other failure modes that can be experienced are discussed in detail by Tallian [19.2]. The following paragraphs deal with a few specific failure types that can affect the conduct of a life test sequence.In Chapter 23, the influence of lubrication on contact fatigue life is discussed from the standpoint of EHL film generation. There ar e also other lubrication-related effects that can affect the outcome of the test series. The first is particulate contaminants in the lubricant. Depending on bearing size, operating speed, and lubricant rheology, the overall thickness of the lubricant film developed at the rolling element-raceway contacts may fall between 0.05 and 0.5 m . Solid particles and damage the raceway and rolling element surfaces, leading to substantially shortened endurances. This has been amply demonstrated by Sayles and MacPherson [19.6] and others.Therefore, filtration of the lubricant to the desired level is necessary to ensure meaningful test result. The desired level is determined by the application which the testing purports to approximate. If thi s degree of filtration is not provided, effects of contamination must be considered when evaluating test results. Chapter 23 discusses the effect of various degrees of particulate contamination, and hence filtration, on bearing fatigue life.The moisture content in the lubricant is another important consideration. It has long been apparent that quantities of free water in the oil cause corrosion of the rolling contact surfaces and thus have a detrimental effect on bearing life. It has been further shown b y Fitch[19.7] and others, however, that water levels as low as 50-100 parts per million(ppm) may also have a detrimental effect, even with no evidence of corrosion. This is due to hydrogen embrittlement of the rolling element and raceway material. See als o Chapter 23. Moisture control in test lubrication systems is thus a major concern, and the effect of moisture needs to be considered during the evaluation of life test results. A maximum of 40 ppm is considered necessary to minimize life reduction effects.The chemical composition of the test lubricant also requires consideration. Most commercial lubricants contain a number of proprietary additives developed for specific purposes; for example, to provide antiwear properties, to achieve extreme pressure and/or thermal stability, and to provide boundary lubrication in case of marginal lubricant films. These additives can also affect the endurance of rolling bearings, either immediately or after experiencing time-related degradation. Care must be taken to ensu re that the additives included in the test lubricant will not suffer excessive deterioration as a result of accelerated life test conditions. Also for consistency of results and comparing life test groups, it is good practice to utilize one standard test lubricant from a particular producer for the conduct of all general life tests.The statistical nature of rolling contact fatigue requires many test samples to obtain a reasonable estimate of life. A bearing life test sequence thus needs a long time. A majo r job of the experimentalist is to ensure the consistency of the applied test conditions throughout the entire test period. This process is not simple because subtle changes can occur during the test period. Such changes might be overlooked until their effects become major. At that time it is often too late to salvage the collected data, and the test must be redone under better controls.For example, the stability of the additive packages in a test lubricant can be a source of changing test conditions. Some lubricants have been known to suffer additive depletion after an extended period of operation. The degradation of the additive package can alter the EH L conditions in the rolling content, altering bearing life. Generally, the normal chemical tests used to evaluate lubricants do not determine the conditions of the additive content. Therefore if a lubricant is used for endurance testing over a long time, a sample of the fluid should be returned to the producer at regular intervals, say annually, for a detailed evaluation of its condition.Adequate temperature controls must also be employed during the test. The thickness of the EHL film is sensitive to the contact temperature. Most test machines are located in standard industrial environments where rather wide fluctuations in ambient temperature are experienced over a period of a year. In addition, the heat generation rates of individual bearings can vary as a result of the combined effects of normal manufacturing tolerances. Both of these conditions produce variations in operating temperature levels in a lot of bearings and affect the validity of the life data. A means must be provided to monitor and control the operating temperature level of each bearing to achieve a degree of consistency. A tolerance level of 3C is normally considered adequate for the endurance test process.The deterioration of the condition of the mounting hardware used with the bearings is another area requiring constant monitoring. The heavy loads used for life te sting require heavy interference fits between the bearing inner rings and shafts. Repeated mounting and dismounting of bearings can produce damage to the shaft surface, which in turn can alter the geometry of a mounted ring. The shaft surface and the bore of the housing are also subject to deterioration from fretting corrosion. Fretting corrosion results from the oxidation of the fine wear particlesgenerated by the vibratory abrasion of the surface, which is accelerated by the heavy endurance test loading.This mechanism can also produce significant variations in the geometry of the mounting surfaces, which can alter the internal bearing geometry. Such changes can have a major effect in reducing bearing test life.The detection of bearing failure is also a major consideration in a life test series. The fatigue theory considers failure as the initiation of the first crack in the bulk material. Obviously there is no way to detect this occurrence in practice. To be detectable the crack must propagate to the surface and produce a spall of sufficient magnitude to produce a marked effect on an operating parameter of the bearing: for example, noise, vibration, and/or temperature. Techniques exit for detecting failures in application systems. The ability of these sys tems to detect earl y signs of failure varies with the complexity of the test system, the type of bearing under evaluation, and other test conditions. Currentl y no single system exists that can consistently provide the failure discrimination necessary for a ll types of bearing life tests. It is then necessary to select a system that will repeatedl y terminate machine operation with a consistent minimal degree of damage.The rate of failure propagation is therefore important. If the degree of damage at test ter mination is consistent among test elements, the only variation between the experimental and theoretical lives is the lag in failure detection. In standard through-hardened bearing steels the failure propagation rate is quite rapid under endurance test cond itions, and this is not a major factor, considering the t ypical dispersion of endurance test data and the degree of confidence obtained from statistical analysis. This may not, however, be the case with other experimental materials or with surface-hardened steels or steels produced by experimental techniques. Care must be used when evaluating these latter results and particularl y when comparing theexperimental lives with those obtained from standard steel lots.The ultimate means of ensuring that an endura nce test series was adequately controlled is the conduct of a post-test analysis. This detailed examination of all the tested bearings uses high-magnification optical inspection, higher-magnification scanning electron microscopy, metallurgical and dimensio nal examinations, and chemicalevaluations as required. The characteristics of the failures are examined to establish their origins and the residual surface conditions are evaluated for indications of extraneous effects that may have influenced the bearin g life. This technique allows the experimenter to ensure that the data are indeed valid. The “Damage Atlas” compiled by Tallian et al. [19.8] containing numerous black and white photographs of the various bearing failure modes can provide guidance for thes e types of determinations. This work was subsequently updated by Tallian [19.9], now including color photographs as well.The post-test analysis is, by definition, after the fact. To provide control throughout the test series and to eliminate all quest ionable areas, the experimenter should conduct a preliminary study whenever a bearing is removed from the test machine. In this portion of the investigation each bearing is examined optically at magnifications up to 30 for indications of improper or out-of-control test parameters. Examples of the types of indications that can be observed are given in Figs. 19.2-19.6.Figure 19.2 illustrates the appearance of a typical fatigue-originated spall on a ball bearing raceway. Figure 19.3 contains a spalling failure on the raceway of a roller bearing that resulted from bearing misalignment, and Fig. 19.4 contains a spalling failure on the outer ring of a ball bearing produced by fretting corrosion on the outer diameter. Figure 19.5 illustr ates a more subtle form of test alteration, `where the spalling failure originated from the presence of a debris denton the surface. Figure 19.6 gives an example of a totally different failure mode produced by the loss of internal bearing clearance due to thermal unbalance of the system.The last four failures are not valid fatigue spalls and indicate the need to correct the test methods. Furthermore, these data points would need to be eliminated from the failure data to obtain a valid estimate of the experimental bearing life.2 .AVOIDING FAILURESThe best way to handle bearing failures is to avoid them．This can be done in the selection process by recognizing critical performance characteristics．These include noise，starting and running torque，stiffness，non-repetitive run out，and radial and axial play．In some applications, these items are so critical that specifying an ABEC level alone is not sufficient．Torque requirements are determined by the lubricant，retainer，raceway quality(roundness cross curvature a nd surface finish)，and whether seals or shields are used．Lubricant viscosity must be selected carefull y because inappropriate lubricant，especially in miniature bearings，causes excessive torque．Also，different lubricants have varying noise characteristics th at should be matched to the application. For example，greases produce more noise than oil．Non-repetitive run out(NRR)occurs during rotation as a random eccentricit y between the inner and outer races，much like a cam action．NRR can be caused by retainer tole rance or eccentricities of theraceways and balls．Unlike repetitive run out, no compensation can be made for NRR.NRR is reflected in the cost of the bearing．It is common in the industry to provide different bearing types and grades for specific applications．For example，a bearing with an NRR of less than 0.3um is used when minimal run out is needed，such as in disk—drive spindle motors．Similarly，machine—tool spindles tolerate only minimal deflections to maintain precision cuts．Consequently, bearings are manufactured with low NRR just for machine-tool applications．Contamination is unavoidable in many industrial products，and shields and seals are commonly used to protect bearings from dust and dirt．However，a perfect bearing seal is not possible because of the movement between inner and outer races．Consequently，lubrication migration and contamination are always problems．Once a bearing is contaminated, its lubricant deteriorates and operation becomes noisier．If it overheats，the bearing can seize．At the very least，contamination causes wear as it works between balls and the raceway，becoming imbedded in the races and acting as an abrasive between metal surfaces．Fending off dirt with seals and shields illustrates some methods for controlling contamination．Noise is as an indicator of bearing quality．Various noise grades have been developed to classify bearing performance capabilities．Noise anal ysis is done with an Ander-on-meter, which is used forquality control in bearing production and also when failed bearings ar e returned for anal ysis. A transducer is attached to the outer ring and the inner race is turned at 1,800rpm on an air spindle. Noise is measured in andirons, which represent ball displacement in μm/rad.With experience, inspectors can identify the smalles t flaw from their sound. Dust, for example, makes an irregular crackling. Ball scratches make a consistent popping and are the most difficult to identify. Inner-race damage is normally a constant high-pitched noise, while a damaged outer race makes an inte rmittent sound as it rotates.Bearing defects are further identified by their frequencies. Generally, defects are separated into low, medium, and high wavelengths. Defects are also referenced to the number of irregularities per revolution.Low-band noise is the effect of long-wavelength irregularities that occur about 1.6 to 10 times per revolution. These are caused by a variety of inconsistencies, such as pockets in the race. Detectable pockets are manufacturing flaws and result when the race is mounted too tightly in multiple jaw chucks.Medium-hand noise is characterized by irregularities that occur 10 to 60 times per revolution. It is caused by vibration in the grinding operation that produces balls and raceways. High-hand irregularities occur at 60 to 300 times per revolution and indicate closely spaced chatter marks or widely spaced, rough irregularities.Classifying bearings by their noise characteristics allows users to specify a noise grade in addition to the ABEC standards used by most manufacturers. ABEC defines physical tolerances such as bore, outer diameter, and run out. As the ABEC class number increase (from 3 to 9), tolerances are tightened. ABEC class, however, does not specify other bearing characteristics such as raceway quality, finish, or noise. Hence, a noise classification helps improve on the industry standard.(come from Lu,Zhengran . Study of the bearing capacity of fastener steel tube full hall formwork support using the theory ofstability of pressed pole with three-point rotation restraint[J] . China Civil Engineering Journal 2012-5 )轴承寿命分析摘要自然界苛刻的工作条件会导致轴承的失效，但是如果遵循一些简单的规则，轴承正常运转的机会是能够被提高的。

C620车床主轴结构改造外文文献翻译、中英文翻译、外文翻译

附录C620 lathe main axle structure transformationdesignRen Fu jun huang ru lin wang qunAbstract: The C620 lathe main axle front bearing, changes present's D3182120 rolling bearing structure by the original sliding bearing, its principal advantage is the rigidity is good, the rotational speed is high, and revolves, the rotation precision to be high steadily, the radial direction beats small, the thermostability to be good as well asthe assembly technology capability is good. Enhances the product advantageously the working accuracy and the productivity, lengthens equipment's service life, reduces themaintenance cost, raises the equipment utilization rate.Key word: Main axle, sliding bearing, rolling bearing, lubrication1 transformation reason lthe C620 lathe main axle front bearing is uses the sliding bearing structure, the spindle speed defined that in n max= in the 600r/min scope, this kind of bearing in high-speed cutting's situation, the bearing is extremely easy to give off heat, the temperature reaches as high as 70 oC; Sped up bearing's natural attrition obviously under this condition, thus reduced main axle's service life, causes the main axle rotation precision gradual reduction, the very great degree has affected the working accuracy and the production benefit.Because sliding bearing's material uses ZQSn6-6-3 generally, the service is complex, the axis blows grinds requests high, the technical difficulty is big, the maintenance cost is also high. Simultaneously the bearing clearance adjustment difficulty, the gap is oversized, the working accuracy reaches does not request; The gap is too small, will appear gives off heat even forms the stuffy vehicle phenomenon.is solves the above malpractice, the sliding bearing changes rolling bearing's structure before the original main axle, simultaneously enhances the spindle speed to nmax=900r/min, made the obsolete equipment to enhance the rigidity and the rotationprecision, raised equipment's use factor.2 transformation processin does not affect the main axle other shafting components structure under thepremise to open the original front bearing, and carries on the remanufacture processing to the original front bearing hole and the main axle. Like Figure 1, shown in Figure 2, and designs the axis front bearing which manufacture as shown in Figure 3. Its structure by the main axle, the end cover, the clamp, the shell, the bearing, the adjusting washer, the bolt, the stopping nut and so on is composed. This structure selected the D3182120 double row centripetal cylindrical roller bearing to transform the C620 lathe main axle front bearing structure, its principal advantage was: The rigidity is good, the rotational speed is high, and revolves steadily, the rotation precision is high, the radial direction beat is small, the thermostability is good as well as assembly technology capability good and so on characteristics. Just before the transformation, must inspect the headstock, the main axle hole size whether can transform.main axle holeFigure 1 after transformation front bearing holeFigure 2 after transformation main axleFigure 3 after transformation main axle front bearing1 main axle2 end cover 3.Clamp 4 shell 5.bearing 6,7.Gasket 8.bolt 9. stopping nutMeets the bearing outer diameter D=150mm size requirement, and inspects the main axle axle diameter whether can transform bearing inside diameter d=100mm the size, when the two meet the above requirement, then begins to arrange the transformation work.2.1 headstock main axle front bearing hole transformationIn order to guarantee lathe main axle hole and rolling bearing outer ring's grade of fit, when processing should follow the basic shaft system the principle, and arranges on the clang bed to carry on the clang hole processing to the headstock front bearing hole. This work must be very careful, achieves the craft precision for the guarantee, truncates when the processing must the bearing hole carry on take the original main axle around as the datum adjusts, around definite main axle bearing hole proper alignment common difference in the 0.015mm scope, before and, main bearing hole aperture processing to 1500-0.022mm; Roundness tolerance.First should inspect the original main axle slipper the journal section size, because the remainder are not many, must grasp the machining allowance. Before the processing, prepares two 5 morse tapers beforehand the craft center end cover (e.g. Figure 4), inlays separately again the end cover before the main axle in the rear end awl hole, and grinds on carefully the end cover the 3mm center bore, then the arrangement on the precision high lathe, with the double thimble's method, carries on the lathe work, according to the bearing in the hole basic hole system's request, processes the main axle journal part the taper is 1: 12 (taper 4o46'19 ") the size 100 requests (request to leave leeway grinding allowance). Simultaneously processes the M100X1.5 axis files adjustment thread separately again, in 1 M100X1.5 adjusting nut and 2 adjusting blocks, the addendum circle adjusting shim (request filling piece thickness leaves leeway sharpeningquantity). Finished, carried on the abrasive machining again to the main axle journal part, met the main axle proper each requirements.Figure 4 before the main axle, bearing meck part transformation3 assemblies and debuggingThe rotation stopping nut makes the end motion to the belt awl's bearing inner rim along the main axle cone-shape then to realize the adjustment. Namely with spanner tight nut 9, when the hand makes an effort moves the main axle the main axle to be able to rotate automatically for 1-2 weeks, then explained that front bearing's radial clearance has adjusted suitably, otherwise the showing gap oversized or is too small, then screws tight the bolt 8. Rear bearing's regulation means and front bearing's regulation means are the same. In order to increase main axle's rotation precision, when assembly uses “the directional assembly” the principle carries on, guaranteed that the rotation precision in design requirements' scope, achieves the re-equipping the goal. After around the bearing assembly, the adjustment finished, carried on 1h the fast idling experiment, the main shaft bearing temperature does not surpass 70oC, then explained that around the main axle the bearing adjustment was suitable.4 reasonable lubrications(1)main shaft bearing's reasonable lubrication is the main axle normal work reliable guarantee, must therefore pay attention to the fuel feed which the main axlefront bearing lubricates. When the summer temperature is high, if the fuel feed are excessively many, not only on the bearing cannot cool and lubricate, because insteadseriously stirs the phenomenon to cause the bearing elevation of temperature; If fuelfeed too few, the bearing lubrication is insufficient, the temperature will also rise,therefore the fuel feed and the blow position had decided bearing's reasonablelubrication, will guarantee bearing's thermostability.(2) headstock's lubricating oil emigration storage in exterior, thus plays the cooling lubricating oil the role, forms coolant conditions which outside an individual circulates, guarantees main axle's normal work.5 increase the headstock spindle speedThe replacement lathe driving pulley (belt pulley), increases the spindle speed by original n max=600r/min to n max=900r/min. Meets the requirements which the spindle speed enhances.Supposition rightful owner drive wheel outer diameter D1=120㎜, namely D1/D2= n1/n2≥120/D2=600/900≥D2=180㎜, increases the driving pulley outer diameter to 180㎜.6 conclusionsAfter the re-equipping C620 lathe, its front bearing structure is reasonable, theadjustment is convenient, makes the main axle system's precision to enhance greatly,also enhanced the engine bed main axle's service life, raised the production efficiency and the product working accuracy effectively, to a great extent reduced equipment's maintenance cost, made the old engine bed to enhance the use value, to raised enterprise's economic efficiency to have the important meaning.C620车床主轴结构改造设计任福君任福君黄如林黄如林汪群汪群摘要摘要::将C620C620型车床主轴前轴承，型车床主轴前轴承，由原来的滑动轴承改为现在的由原来的滑动轴承改为现在的D3182120D3182120D3182120滚动轴滚动轴承结构，其主要优点是刚性好、转速高且运转平稳、回转精度高、径向跳动小、热稳定性好以及装配工艺性好。

机械类英语论文翻译.doc

机械类英语论文翻译.doc轴承内径 bearing bore diameter轴承寿命 bearing life轴承套圈 bearing ring轴承外径 bearing outside diameter轴颈 journal轴瓦、轴承衬 bearing bush轴端挡圈 shaft end ring轴环 shaft collar轴肩 shaft shoulder轴角 shaft angle轴向 axial direction轴向齿廓 axial tooth profile轴向当量动载荷 dynamic equivalent axial load轴向当量静载荷 static equivalent axial load轴向基本额定动载荷 basic dynamic axial load rating轴向基本额定静载荷 basic static axial load rating 轴向接触轴承 axial contact bearing轴向平面 axial plane轴向游隙 axial internal clearance轴向载荷 axial load轴向载荷系数 axial load factor轴向分力 axial thrust load主动件 driving link主动齿轮 driving gear主动带轮 driving pulley转动导杆机构 whitworth mechanism转动副 revolute (turning) pair转速 swiveling speed rotating speed转动关节 revolute joint转轴 revolving shaft转子 rotor转子平衡 balance of rotor装配条件 assembly condition锥齿轮 bevel gear锥顶 common apex of cone锥距 cone distance锥轮 bevel pulley; bevel wheel锥齿轮的当量直齿轮 equivalent spur gear of the bevel gear 锥面包络圆柱蜗杆 milled helicoids worm准双曲面齿轮 hypoid gear子程序 subroutine子机构 sub-mechanism自动化 automation自锁 self-locking自锁条件 condition of self-locking自由度 degree of freedom, mobility。

[整理]各种轴承英文翻译

ACBB 深沟球轴承CRB 滚柱轴承NRB 滚针轴承SRB 调心轴承TRB 圆锥滚子轴承SRB 剖分式圆柱滚子轴承NCF 单列满滚子圆柱滚子轴承DGBB 深沟球轴承各种轴承英文翻一．轴承：(一)滚动轴承总论1. 滚动轴承rolling bearing在支承负荷和彼此相对运动的零件间作滚动运动的轴承，它包括有滚道的零件和带或不带隔离或引导件的滚动体组。

可用于承受径向、轴向或径向与轴向的联合负荷。

2. 单列轴承single row bearing具有一列滚动体的滚动轴承。

3. 双列轴承double row bearing具有两列滚动体的滚动轴承。

4. 多列轴承multi-row bearing具有多于两列的滚动体，承受同一方向负荷的滚动轴承，最好是指出列数及轴承类型，例如："四列向心圆柱滚子轴承"。

5. 满装滚动体轴承full complement bearing无保持架的轴承，每列滚动体周向间的间隙总和小于滚动体的直径并尽可能小，以使轴承有良好的性能。

6. 角接触轴承angular contact bearing公称接触角大于0°而小于90°的滚动轴承。

7. 调心轴承self-aligning bearing一滚道是球面形的，能适应两滚道轴心线间的角偏差及角运动的轴承。

8. 可分离的轴承separable bearing具有可分离部件的滚动轴承。

9. 不可分离轴承non-separable bearing在最终装配后，轴承套圈均不能任意自由分离的滚动轴承。

注：对于不同方法分离零件的轴承，例如有双半套圈（02、01、08）的球轴承不另规定缩略术语。

10. 英制轴承inch bearing原设计时外形尺寸及公差以英制单位表示的滚动轴承。

11. 开型轴承open bearing无防尘盖及密封圈的滚动轴承。

12. 密封圈轴承sealed bearing一面或两面装有密封圈的滚动轴承。

常用轴承的英文术语概论

第1章滚动轴承(rolling bearing）1.1 向心轴承(contact ball bearing1.1.1 深沟球轴承(deep grove ball bearing)1.1.2 圆柱滚子轴承(cylindrical roller bearing)1.1.3 滚针轴承(needle bearing)1.1.4 调心球轴承(self-aligning ball bearing)1.1.5 角接触球轴承(angular-contact ball bearing)1.1.6 圆锥滚子轴承(tapered roller bearing)1.1.7 调心滚子轴承(self-aligning roller bearing)1.2 推力轴承(thrust bearing)1.2.1 推力球轴承(thrust ball bearing)1.2.2 推力圆柱滚子轴承(thrust cylindrical roller bearing)1.2.3 推力滚针轴承(thrust needle bearing)1.2.4 推力角接触球轴承(thrust angular-contact ball bearing) 1.2.5 推力调心滚子轴承(thrust self-aligning roller bearing) 1.3 组合轴承(combined bearing)1.4 外球面球轴承(spherical surface ball bearing)1.5 直线运动滚动支承(linear roll bearing)1.6 滚轮滚针轴承（tracd & needle roller bearing）1.7 水泵轴连轴承（water pump bearing）1.8 专用轴承(special bearing)1.9 滚动轴承附件(fitting parts for rolling bearing)第2章滑动轴承(plain bearing)2.1 关节轴承(articulated bearing)2.1.1 杆端关节轴承(rod end & spherical plain bearing)2.1.2 向心关节轴承(plain radial bearing)2.1.3 角接触关节轴承(angular-contact articulated bearing)2.1.4 推力关节轴承(thrust articulated bearing)2.2 其他滑动轴承(others plain bearing)2.3 滑动轴承轴套与轴瓦(bushing & half-liner of plain bearing) 2.3.1 轴套(plain bearing bushing)2.3.2 轴瓦(plain bearing half-liner)2.4 滑动轴承附件(fitting parts for plain bearing)第3章详细分类adapter bearing带固接套的轴承adjustable bearing可调轴承adjustable cone colter bearing圆犁刀的可调式锥形轴承aerostatic bearing空气静力轴承agate bearing玛瑙轴承air journal bearing气体轴承air lubricated thrust bearing空气润滑止推轴承aligning bearing(直线)对位轴承alkaline-friction bearing抗磨轴承allowable bearing容许支承力all-rubber type bearing全胶式轴承。

外文翻译-- 发动机曲轴箱轴承座裂解加工数值分析

毕业设计(论文)外文资料翻译学院(系)：机械工程学院专业：机械工程及自动化姓名：学号：外文出处：Numerical analysis on fracture Splitting(用外文写)technology of bearing block of engine附件： 1.外文资料翻译译文；2.外文原文。

注：请将该封面与附件装订成册。

附件1：外文资料翻译译文发动机曲轴箱轴承座裂解加工数值分析预先精确计算裂解力参数,对于裂解设备设计及工艺过程的制定至关重要。

应用MSC. MARC 软件对捷达轿车发动机主轴承座(以Ru T380 材料为例) 起裂过程进行数值模拟,得出了裂解力与J 积分的关系曲线。

根据J 积分值与断裂韧性的关系,确定了临界J 积分,采用线性插值的方法获得了裂解力,并进行了实验研究。

实验结果表明:此方法也适用于不同结构、不同材料的其他分体类零件裂解加工时裂解力的确定。

裂解技术是分体类零件加工领域中一项新型加工工艺,其本质是利用材料的脆性,在人为制造裂解源的前提下,通过外力使其断裂,达到剖分体分离的目的,这就要求材料和结构既要满足零件的机械力学性能和使用寿命,又要适合裂解工艺的要求且要保证裂解质量。

汽车发动机曲轴箱轴承座的加工与连杆轴承孔的加工在结构、工艺流程方面都适合于裂解工艺。

发动机缸体多采用优质灰铸铁、球墨铸铁、蠕墨铸铁等制造,都具有良好的脆性和机械加工性能,适合于裂解加工工艺并容易加工裂解槽。

曲轴箱轴承座具有多个轴承孔结构,因此裂解设备需要具备裂解多个轴承孔的能力。

所以发动机曲轴箱轴承座较之连杆轴承孔更适合于裂解工艺,工艺更加复杂,效益更加明显。

作者应用MSC. MARC 软件对捷达轿车发动机曲轴箱轴承座(以Ru T380 材料为例)起裂过程进行数值模拟,从而确定裂解加工中合适的裂解力参数,并进行了实验验证。

裂解加工的原理是通过在曲轴箱轴承孔中心处设计并预制缺口(初始裂纹槽) ,形成应力集中,再主动施加垂直于预定断裂面的载荷进行引裂,当满足发生脆性断裂的条件时,在几乎不发生塑性变形的情况下,在缺口处规则断裂,实现轴承座体与盖的无屑断裂剖分[5 ] ,如图1 所示。

各种轴承英文翻译

各种轴承英文翻译轴承承英文翻翻译第 1 章滚动轴承承(rolling bearing) 1.1 向心轴承(co ontact ball b bearing) 1.1.1 深沟球轴承承(deep gro ball bear ove ring) 1.1.2 圆柱滚子轴轴承(cylindr rical roller be earing) 1.1.3 滚针轴承( (needle bea aring) 1.1.4 调心球轴承 4 承(self-align ning ball bea aring) 1.1.5 角接触球轴轴承(angula ar-contact ba bearing) all 1.1.6 圆锥滚子轴轴承(tapered roller bear d ring) 2.2 其他滑动轴轴承(others p plain bearing g) 1.1.7 调心滚子轴轴承(self-aligning roller bearing) 2.3 滑动轴承轴轴套与轴瓦(b bushing & half-liner of plain h 1.2 推力轴承(th hrust bearing g) 1.2.1 推力球轴承承(thrust ball bearing) 1.2.2 推力圆柱滚子轴承 (thrust cylindrical ro oller bearing) 1.2.3 推力滚针轴轴承(thrust n needle bear ring) 1.2.4 推力角接 4 接触球轴承(t thrust angular-contact ball bearing) 1.2.5 推力调心滚子轴承 (thrust self f-aligning ro oller bearing) 1.3 组合轴承(co ombined bearing) 承 1.4 外球面球轴轴承(spherica surface ba bearing) al all aer rostatic bear ring 空气静力力轴承 1.5 直线运动滚滚动支承(linea roll bearin ar ng) aga bearing 玛瑙轴承 ate 玛1.6 滚轮滚针轴轴承（tracd & needle rolle bearing） er air journal bear ring 气体轴承承 1.7 水泵轴连轴轴承（water p pump bearin ng） air lubricated th hrust bearing 空气润滑止 g 止推轴承 1.8 专用轴承(sp pecial bearin ng) alig gning bearing(直线)对位位轴承ada apter bearing 带固接套的的轴承 adjustable bearing 可调轴承承adjustable cone colter bea aring 圆犁刀刀的可调式锥锥形轴bea aring) 2.3.1 轴套(plai bearing b in bushing) 2.3.2 轴瓦(plai bearing h alf-liner) in 2.4 滑动轴承附附件(fitting pa for plain bearing) arts n 1.9 滚动轴承附附件(fitting pa for rollin bearing) arts ng 第 2 章滑动轴承(plain bea aring) 2.1 关节轴承(a articulated b bearing) 2.1.1 杆端关节节轴承(rod en & spheric plain bea nd calaring) 2.1.2 向心关节节轴承(plain r radial bearin ng) 2.1.3 角接触关节轴承 ( (angular-con ntact articul lated bea aring) 2.1.4 推力关节节轴承(thrust articulated bearing)alka aline-friction bearing 抗磨磨轴承 allow wable bearin 容许支承 ng 承力 all-rubber type b bearing 全胶胶式轴承。

高速旋转机械中英文对照外文翻译文献

中英文对照外文翻译文献(文档含英文原文和中文翻译)Low Power Magnetic Bearing Design For High Speed Rotating MachineryP. E. Allaire, E. H. Maslen, and R. R. Humphris, Department of Mechanical and Aerospace Engineering University of Virginia Charlottesville, VA 22901C. K. Sortore Aura Systems, Inc. EI Segundo, CA 90245 P. A. Studer Magnetic Concepts Silver Springs, MD 20901 317SUMMARYAgnetic suspension technology has advanced to the point of being able to offer a number of advantages to a variety of applications in the rotating machinery and aerospace fields. One strong advantage of magnetic bearings over conventional bearings is the decrease in power consumption. The use of permanent magnets, along with electromagnets, is one appealing option which can further reduce the power consumption of the bearing.The design and construction of a set of permanent magnet biased, actively controlled magnetic bearings for a flexible rotor is presented. Both permanent magnets and electromagnets are used in a configuration which effectively provides the necessary fluxes in the appropriate air gaps, while simultaneously keeping the undesirable destabilizing forces to a minimum. The design includes two radial bearings and a thrust bearing.The theoretical development behind the design is briefly discussed. Experimental performance results for a set of operating prototype bearings is presented. The results include measurements of load capacity, bearing stiffness and damping and the dynamic response of the rotor. With few exceptions, the experimental measurements matched very well with the predicted performance. The power consumption of these bearings was found to be significantly reduced from that for a comparable set of all electromagnetic bearing.INTRODUCTIONMagnetic bearings have a number of strong advantages. One most obvious advantage is their non~ontacting, virtually friction-free characteristics. Entire lubrication systems and the need for mechanical oil seals, which add to friction losses and instabilities associated with cross coupled bearing coefficients, can be eliminated by using these types of bearings. The life expectancy of a magnetic bearing, in many cases, can be much higher than that of conventional bearing. Due to the non~ontacting nature of the bearings, mechanical parts do not wear out. This can obviously increase system reliability and decrease costly repairs and necessary maintenance which interrupt profitable machine operation. If designed properly, a magnetic bearing can perform under much harsher conditions and environments for extended periods of time which would not be possible with other types of bearings. One further advantage of the frictionless characteristic of these bearings is that of power loss. The power consumption of a conventional fluid-film bearing is in many cases much more than for a magnetic bearing. Power loss reductions of one order of magnitude or more canbe expected when a machine is converted from using conventional bearings to magnetic bearings.A variety of work has been accomplished on a number of different applications and aspects of magnetic bearings. An extensive amount of research has been performed by a number of university and industry researchers on the development of magnetic bearings in an· industrial canned motor pump [1]. A number of other successful industrial applications of magnetic bearings has been reported by Weise [21. Burrows et. al. [3] presents the development and application of a magnetic bearing specifically designed for the vibration control of a flexible rotor. Keith, et. al. [4] successfully developed a PC-based digital controller for magnetic bearings. Continuing research is being performed in the areas of digital and adaptive controls for magnetic bearings. In researching the use of permanent magnets in combination with electromagnets, of particular interest are two patents credited to Philip Studer [5, 6]. These patents contain a number of features, primarily dealing with permanent magnets, which have useful application to the bearings discussed in this paper. Wilson and Stu~er [7] have also applied the permanent magnet bias concept to a linear motion bearing. Ohkami et. al. [8] have performed some interesting comparison studies of magnetic bearings of various configurations which use permanent magnets. Another paper by Tsuchiya et. al. [9] studies and comments on the stability of a high speed rotor which is suspended in magnetic bearings biased with permanent magnets. Meeks [10] has also performed a comparison of the various magnetic bearing design approaches and concludes that the combining of actively controlled electromagnets with permanent magnets results in a superior magnetic bearing in terms of size, weight and power consumption. The rare earth permanent magnets of today, in particular Sm-Co and Nd-Fe-Bo magnets, offer very high performance characteristics in terms of magnetic strength, energy product and thermal qualities. The magnet designer is able to concentrate a very large amount of magnetic energy in a small package, making more efficient use of available space.The design concept for the permanent magnet biased magnetic bearing design discussed in this paper is a variation on research and development reported by Studer [5, 6]. The following two sections give a brief description of how the bearings conceptually operate.Radial MagnetiC Bearing DescriptionA diagram of a permanent magnet biased radial magnetic bearing is shown in Figure 1. This bearing is designed to operate at one end of the rotor and control radial forces only. Four axially magnetized arc segment magnets are positioned circumferentially adjacent to the stator. The bias flux generated by the permanent magnets passes down the laminatedstator pole leg, through the working air gap, axially along the shaft, then returns to the permanent magnet via . a radial bias pole piece. The active control flux generated by the coils also passes down the stator pole leg and through the working air gap. The return path for the active flux is then circumferentially around the stator, as shown in Figure 1. This design requires only four poles and four coils, unlike an all electromagnetic design which generally requires eight. In addition, since the coils for each bearing axis are connected in series, the bearing control system requires only five current amplifier channels, which is half as many as required of the all electromagnetic bearing.Combination Radial/Thrust Magnetic Bearing DescriptionA schematic of this bearing design, revealing the various magnetic paths, is shown in Figure 2. This bearing combines control of both radial and thrust forces. The radial portion of the bearing is identical to that which was described in the previous section. The thrust control however, is implemented by a unique magnetic flux configuration. The permanent magnet bias flux passing along the shaft splits equally between the two thrust poles before returning to the permanent magnet. A single active coil produces a magnetic flux, in the shape of a toroid, which symmetrically adds or subtracts to the bias flux in the working air gaps between the thrust disk and thrust poles.Design ConceptThe bearings designed for this project are different from all electromagnetic bearing designs in that they employ both permanent magnets and electromagnets. Permanent magnets generate the bias flux in the working air gaps and electromagnets are used to modulate this flux.The purpose of establishing a bias flux in the working air gaps is to linearize the governing force equation of the magnetic actuator. The bias flux is a nominal flux density about which the control flux is varied. If a bias flux of zero is used, (only one opposing actuator is operated at a time,) then the force generated by the actuator on the rotor follows a quadratic force law, i.e., the force will be proportional to the square of the flux density in the air gaps. Consequently, the force slew rate will be zero when the rotor is in the nominal balanced position and the transient response will be adversely effected. If, however, the bearing fluxes are modulated about a non-zero bias flux, (with opposing actuators symmetrically perturbed,) it is easily shown that the force becomes linearly related to the control flux. The following section demonstrates this important relation.Force RelationshipsThe force generated in an air gap of area Ag and length g by a magnetic actuator can be expressed by the direct relationwhere Bg is the flux density in the air gap and J.Lo is the permeability of free space. If only a single axis of the bearing is considered, then the net force acting on the shaft will be the difference of the two opposite acting actuator forces. Assuming the areas of the two opposing air gaps are the same, the force acting on the shaft by the magnetic bearing can be expressed asThe flux density in the air gaps is being supplied by two sources, i.e., the permanent magnet and the coil. In order to properly provide differential control, the fluxes in the two gaps are symmetrically perturbed so that the flux in one gap is increased while the flux in the opposite gap is decreased by the same amount. This implies thatwhere Bpm is the flux density generated by' the permanent magnet and Be is the flux density generated by the coil. Substituting Eqs. l3, 4) into Eq. (2), expanding and simplifying, the force acting on the shaft can now be expressed asBy expressing the equation for the force on the shaft in this form, it is interesting to note that the force is not only proportional to the bias level, Bpm, but it is also linearized with respect to the control flux, Be. .Open Loop Stiffness and Actuator Gain The force generated by the bearing in the horizontal direction, F x, can be accurately approximated by the truncated Taylor series expansion in the following way:If tne magnetic circuit is balanced, then the first term in Eq. (6) is equal to zero andwhere x represents the rotor displacement and ie represents the control current in the electromagnetic coil. The parameters Kx and Ki are defined ashe quantity Kx is referred to as the open loop stiffness and represents the change in the horizontal force due to horizontal displacement. The open loop stiffness is always negative which implies that the bearing is unstable in the open loop control configuration. Unlike a actual spring with a positive stiffness, a positive dispacement of the rotor toward the magnet will increase the attractive force. The quantity Ki represents the actuator gain of the bearing. It represents changes in the horizontal force due to control current, ie. Equivalent expressions exist for the components of the vertical force expression. Expressions for the open loop stiffness and the actuator gain are determined by performing the appropriate differentiation of the force expression. These expressions take on the formwhere Land H represent the length and demagnetization force, respectively, of the permanent magnet and N is the number of turns in the electromagnetic coil.Control System DescriptionThe control elements of this system are those components which detect the motion of the shaft, determine the required control force and generate a coil current required by the magnetic bearing to generate this force. The magnetic bearing system consists of four distinct components: the magnetic actuator, the displacement sensors and associated conditioning circuits, the analog PID controller and the power amplifier.The actual magnetic bearing mainly consists of the electromagnetic coils, iron polepieces, rotor and permanent magnets. The signal conditioning component consists of the eddy current induction displacement sensors, signal amplification and coordinate transformation circuits. The analog controller primarily consists of three separate components. The components take the form of proportional (P), integral (I) and derivative (D) compensation networks. These three parallel stages are added together through a summing amplifier to produce the output of the analog controller. The last component in the control loop is the power amplifier. The amplifier, upon request of the controller, supplies the required current to magnetic coils to produce the necessary fluxes in the bearing.The dynamics of the bearing-rotor system can be combined with the operating characteristics of the control electronics to form a closed-loop control system. This control system is shown in a simplified block diagram form in Figure 3. The displacement sensor characteristics, analog controller and amplifier make up the relatively complex transfer function of the feedback controller, Gc(s). The feedback controller relates the rotor position to the actuator current. The closed-loop transfer function for this magnetic bearing system, as determined from this block diagram, is given bywhere m is the mass of the rotor supported by the bearing.Prototype Bearing ConstructionThe four-pole radial bearing stators, as shown in the diagrams of Figures 1 and 2, were designed to be identical for both bearings. The stators and rotors were constructed of 3% silicon-iron lamination material which had a thickness of 0.007 inches. Each laminated component consists of approximately 100 laminations. The laminations were glued together using a two part activator/resin adhesive and the shape was machined by wire EDM (electric discharge machining.) The bearing stators have an outside diameter of approximately 3.0 inches and an axial length of approximately 0.7 inches. The outside diameter of the laminated rotor is approximately 1.5 inches. The thrust bearing components were machined from soft magnet iron. The high energy permanent magnets, made out of a geodymium-Iron-Boron alloy, have a maximum energy product of 30 MG-Oe. The bearings support a shaft weighing approximately 3.7 Ibm.Load CapacityMeasurements of the maximum load applied to the shaft, before falling out of support,are plotted as a function of proportional controller gain, Kp, in Figure 4. The force in this test was applied by hanging weights on the shaft. A pulley system was constructed in such a way that the force could be applied in the desired direction. The force in the plots represents forces applied along the bearing axes.The variation of the maximum load at lower proportional gains is actually a measure of the stability threshold of the system. It is noted in Eq. t 8) that the open loop stiffness, Kx is defined at a nominal operating point, i.e., rotor position and control current equal to zero. However, as the bearing is loaded with a static force, the steady state current begins to increase. It can be shown analytically that Kx is a function of the operating point of the control current. That is, as the control current current increases, Kx also increases. Increasing proportional gain has the effect of compensating for this increase in Kx and consequently increasing the stability of the system.The measurements made at higher proportional gains represent a more accurate measure of the actual load capacity of the bearing. Enough stability is provided so that magnetic saturation is reached in the bearing pole structures. The maximum predicted loads in the plots of Figure 4 are calculated at the point of magnetic saturation.Equivalent Bearing Stiffness and DampingMeasurements of the equivalent stiffness of the bearings are shown in Figure 5. This simple measurement was performed by applying a constant force, ~F , and noting the displacement, ~x , of the shaft (controller integrators turned off.) The stiffness then is given simply by Keq= ~F / ~x. A linear regression was performed on the measured data, which resulted in very good correlation, as can be observed in the plots. It is noted that the proportional gain has a direct effect on the stiffness of the bearings, as has been previously demonstrated by Humphris, et. al. [11].Relative damping in the bearings was investigated from a white noise frequency response analysis of the bearing and rotor. The analysis was performed by injecting noise, composed of all frequencies of interest, into one axis of the turbine-end radial bearing, and performing a FFT (Fast Fourier Transform) analysis on the vibration response of that axis. This linear frequency response, composed of 100 averages, is shown in Figure 6. The derivative controller gain, Kr was varied through a range of values as noted in the plot. As expected, the derivative gain had a direct effect on the damping in the bearings [11]. The first large spike represents the first two modes of shaft vibration. They are very close together in frequency and essentially indistinguishable. The frequency of the second spike is the third mode of vibration and the third small spike at approximately 60,000 cpm is the fourth mode. It is noted that the variation of the derivative gain strongly effects the firsttwo modes, has a small effect on the third mode and virtually no influence on the vibration amplitude of the fourth mode.Critical Speeds and Rotor ResponseThe damped synchronous critical speeds of the flexible shaft supported by these bearings can be approximately determined from the white noise frequency response plots of Figure 6. These values, however, represent the zero speed natural frequencies, and the gyroscopic stiffening effects of any attached disks would not be included. Since the natural frequency is given by ,where k is the shaft stiffness and m in the modal mass of the rotor, it is of course expected that the observed critical speeds, when the shaft was spinning, would be higher.Plots showing the vibration magnitude and phase for the shaft speeds that were obtained is included in Figure 7. Amplitude information was taken directly from the magnetic bearing sensors and a key-phase sensor was used to provide the phase information. According to the maximum vibration amplitudes observed in Figure 7, the first vibration mode is observed to occur at approximately 10,000 rpm and the second at approximately 13,000 rpm.Power ConsumptionFinally, a number of power consumption measurements were made. Measurements of the power were taken with a wattmeter for a number of cases. This meter is used with the assumption that the measured voltage and current being supplied to the control electronics is sinusoidal in nature. In addition, it is realized that it represents a somewhat gross measurement as it includes all the inefficiencies of the various electronic components. Table 1 summarizes the results. The non~ssential electronic diagnostic components of the bearing system were observed to consume only about 7 watts. These measurements represent a significant improvement over the 500 watts of approximate total power consumed by a comparable current biased all electromagnetic bearing design.CONCLUSIONSThe brief theory which was presented in this paper established the basic electromagnetic and mechanical relationships necessary to develop a set of permanent magnet biased magnetic bearings. The design involved both radial and thrust bearings. The availability of newer rare-earth high energy permanent magnets made it possible to effectively provide the necessary bias fluxes in the bearing.The bearings and rotor were successfully constructed and operated. A number of tests and experiments were performed on the bearing-rotor system. The tests consisted of loadcapacity, stiffness and damping measurements. The results proved to be very positive in that the theoretical predictions and the observed performance matched reasonably well, giving credibility to the models which were used to perform the analysis. Of particular interest for this study was the measured power consumption of the bearings. It clearly demonstrates that the use of permanent magnets can improve the operating efficiency of an active magnetic bearing.It was successfully observed and demonstrated that these bearings have strong potential for future use as efficient, reliable bearings. However, further research and development is required in the areas of controls, magnetic materials and actuator design before it is possible to install them into a useful industrial application.R EFERENCES1. Allaire P.; Imlach, J.; McDonald, J.; Humphris, R.; Lewis, D.; Banerjee, B.; Blair, B.;Clayton, J.; Flack, R.: "Design, Construction and Test of Magnetic Bearings in an Industrial Canned Motor Pump," Pump Users Symposium, Texas A & M, Houston, TX, May 1989.2. Weise, D. A.: "Present Industrial Applications of Active Magnetic Bearings," Presentedat the 22nd Intersociety Energy Conversion Engineering Conference, Philadelphia, Pennsylvania, August 1987.3. Burrows, C. R., Sahinkaya, N.; Traxler, A.; and Schweitzer, G.: "Design andApplication of a Magnetic Bearing for Vibration Control and Stabilization of a Flexible Rotor," Proceedings of the First International Magnetic Bearings Symposium, ETH Zurich, Switzerland, June 1988.4. Keith F. J., Williams, R. D.; Allaire, P. E.; and Schafer, R. M.: "Digital Control ofMagnetic Bearings Supporting a Multimass Flexible Rotor," Presented at the Magnetic Suspension Technology Workshop, Hampton, Virginia, February 1988.5. Studer. P. A.: NASA, Magnetic Bearing, Patent 3865442, Patent Application 100637,February 1975. 6. Studer, P. A.: NASA, Linear Magnetic Bearing, Patent 4387935, Patent Application 214361, December 1980.7. Wilson, M.; and Studer, P. A.: "Linear Magnetic Bearings," Presented at the InternationalWorkshop on Rare Earth-Cobalt Magnets and Their Applications, Roanoake, Virginia, June 1981.8. Ohkami, Y., Okamato, 0.; Kida, T.; Murakami, C.; Nakajima, A.; Hagihara, S.; andYabuuchi, K.: "A Comparison Study of Various Types of Magnetic Bearings Utilizing Permanent Magnets," Presented at the International Workshop on Rare Earth-Cobalt Permanent Magnets and Their Applications, Roanoake, Virginia, June 1981.9. Tsuchiya, K; Inoue, M.; Nakajima, A.; Ohkami, Y.; and Murakami, C.: "On Stability ofMagnetically Suspended Rotor at High Rotational Speed,." Presented at the Aerospace Sciences Meeting, Reno, Nevada, January 1989.10. Meeks, C.: "Trends in Magnetic Bearing Design," Paper presented at Naval SeaSystems Command Magnetic Bearing Forum, Washington, D. C., July 1989.高速旋转机械的低功率磁力轴承设计总结:磁悬液研究具有先进的研发技术，有一定的优势，广泛应用于旋转机械和航空航天等领域。

Bearings English 轴承专业英语汇集

轴承专业英语汇集［轴承中英文对照］一、轴承(一)滚动轴承总论1. 滚动轴承rolling bearing ['rəuliŋ]2. 单列轴承single row bearing [rau]3. 双列轴承double row bearing4. 多列轴承multi-row bearing ['mʌlti]5. 满装滚动体轴承full complement bearing [ful] ['kɔmplimənt]6. 角接触轴承angular contact bearing ['æŋɡjulə]7. 调心轴承self-aligning bearing [ə‘lainiŋ]8. 可分离的轴承separable bearing ['sepərəbl]9. 不可分离轴承non-separable bearing10. 单列深沟球轴承是球轴承中最普通的种类，应用及其广泛。

Single row deep groove ball bearings are the most common type of rolling bearing and are used in a wide variety [və'raiəti] of applications.The moment of friction of high-speed grease-lubricated rolling bearing determines its power consumption and heat output,and the heat output has a direct effect on its temperature rise.在高速脂润滑滚动轴承中,摩擦力矩的大小决定了轴承的功率消耗和发热量的大小,发热量的大小直接影响轴承的温升失效。

10. 英制轴承inch bearing inch [intʃ]11. 开型轴承open bearing open ['əupən]12. 密封圈轴承sealed bearing sealed [si:ld]13. 防尘盖轴承shielded bearing shielded ['ʃi:ldid]14. 闭型轴承capped bearing15. 预润滑轴承prelubricated bearing [pri:‘ljubrikeitid]16. 仪器精密轴承instrument precision bearing ['instrumənt] [pri'siʒən]17. 组配轴承matched bearingSealed bearing system reduces clamping pressure and increases bearing life.密封的轴承系统减少夹持力并增加轴承寿命。

滚动轴承机械外文翻译中英文

附录附录1英文原文Rolling Contact BearingsThe concern of a machine designer with ball and roller bearings is fivefold as follows:(a) life in relation to load; (b) stiffness,i.e.deflections under load; (c) friction;(d) wear; (e) noise. For moderate loads and speeds the correct selection of a standard bearing on the basis of a load rating will become important where loads are high,although this is usually of less magnitude than that of the shafts or other components associated with the bearing. Where speeds are high special cooling arrangements become necessary which may increase fricitional drag. Wear is primarily associated with the introduction of contaminants,and sealing arrangements must be chosen with regard to the hostility of the environment.Because the high quality and low price of ball and roller bearing depends on quantity production,the task of the machine designer becomes one of selection rather than design. Rolling-contact bearings are generally made with steel which is through-hardened to about 900HV,although in many mechanisms special races are not provided and the interacting surfaces are hardened to about 600HV. It is not surprising that,owing to the high stresses involved,a predominant form of failure should be metal fatigue, and a good deal of work is based on accept values of life and it is general practice in bearing industry to define the load capacity of the bearing as that value below which 90 percent of a batch will exceed life of one million revolutions.Notwithstanding the fact that responsibility for basic design of ball and roller bearings rests with he bearing manufacturer, the machine designer must form a correct appreciation of the duty to be performed by the bearing and be concerned not only with bearing selection but with the conditions for correct installation.The fit of the bearing races onto the shaft or onto the housings is of critical importance because of their combined effect on the internal clearance of the bearing as well as preserving the desired degree of interference fit. Inadequate interference can induce serious trouble from fretting corrosion. The inner race is frequently located axially by against a shoulder. A radius at this point is essential for the avoidance ofstress concentration and ball races are provided with a radius or chamfer to follow space for this.Where life is not the determining factor in design, it is usual to determine maximum loading by the amount to which a bearing will deflect under load. Thus the concept of "static load-carrying capacity" is understood to mean the load that can be applied to a bearing, which is either stationary or subject to slight swiveling motions, without impairing its running qualities for subsequent rotational motion. This has been determined by practical experience as the load which when applied to a bearing results in a total deformation of 0.0025mm for a ball 25mm in diameter.The successful functioning of many bearings depends upon providing them with adequate protection against their environment, and in some circumstances the environment must be protected from lubricants or products of deterioration of the bearing design. Moreover, seals which are applied to moving parts for any purpose are of interest to tribologists because they are components of bearing systems and can only be designed satisfactorily on basis of the appropriate bearing theory.Notwithstanding their importance, the amount of research effort that has been devoted to the understanding of the behavior of seals has been small when compared with that devoted to other aspects of bearing technology.LathesLathes are widely used in industry to produce all kinds of machined parts. Some are general purpose machines, and others are used to perform highly specialized operations.Engine lathesEngine lathes, of course, are general-purpose machine used in production and maintenance shop all over the the world. Sized ranger from small bench models to huge heavy duty pieces of equipment. Many of the larger lathes come equipped with attachments not commonly found in the ordinary shop, such as automatic shop for the carriage.Tracer or Duplicating LathesThe tracer or duplicating lathe is designed o produce irregularly shaped parts automatically. The basic operation of this lathe is as fallows. A template of either a flat or three-dimensional shape is placed in a holder. A guide or pointer then moves along this shape and its movement controls that of the cutting tool. The duplication may include a square or tapered shoulder, grooves, tapers, and contours. Work such asmotor shafts, spindles, pistons, rods, car axles, turbine shafts, and a variety of other objects can be turned using this type of lathe.Turret LathesWhen machining a complex workpiece on a general-purpose lathe, a great deal of time is spent changing and adjusting the several tools that are needed to complete the work. One of the first adaptations of the engine lathe which made it suitable to mass production was the addition of multi-tool in place of the tailstock. Although most turrets have six stations, some have as many as eight.High-production turret lathes are very complicated machines with a wide variety of power accessories. The principal feature of all turret lathes, however, is that the tools can perform a consecutive serials of operations in proper sequence. Once the tools have been set and adjusted, little skill is require to run out duplicate parts.Automatic Screw MachineScrew machines are similar in construction to turret lathes, except that their heads are designed to hold and feed long bars of stock. Otherwise, their is little different between them. Both are designed for multiple tooling, and both have adaptations for identical work. Originally, the turret lathe was designed as a chucking lathe for machining small casting, forgings, and irregularly shaped workpieces.The first screw machines were designed to feed bar stock and wire used in making small screw parts. Today, however, the turret lathe is frequently used with a collect attachment, and the automatic screw machine can be equipped with a chuck to hold castings.The single-spindle automatic screw machine, as its name implies, machines work on only one bar of stock at a time. A bar 16 to 20 feet long is feed through the headstock spindle and is held firmly by a collect. The machining operations are done by cutting tools mounted on the cross slide. When the machine is in operation, the spindle and the stock are rotated at selected speeds for different operations. If required, rapid reversal of spindle direction is also possible.In the single-spindle automatic screw machine, a specific length of stock is automatically fed through the spindle to a machining area. At this point, the turret and cross slide move into position and automatically perform whatever operations are required. After the machined piece is cut off, stock is again fed into the machining area and the entire cycle is repeated.Multiple-spindle automatic screw machines have from four to eight spindleslocated around a spindle carrier. Long bars of stock, supported at the rear of the machine,pass though these hollow spindles and are gripped by collects. With the single spindle machines, the turret indexes around the spindle. When one tool on the turret is working, the others are not. With a multiple spindle machine, however, the spindle itself index. Thus the bars of stock are carried to the various end working and side working tools. Each tool operates in only one position, but tolls operate simultaneously. Therefore, four to eight workpieces can be machined at the same time.Vertical Turret LathesA vertical turret is basically a turret lathe that has been stood on its headstock end. It is designed to perform a variety of turning operations. It consists of a turret, a revolving table, and a side head with a square turret for holding additional tools. Operations performed by any of the tools mounted on the turret or side head can be controlled through the use of stops.Machining CentersMany of today's more sophisticated lathes are called machining centers since they are capable of performing, in addition to the normal turning operations, certain milling and drilling operations. Basically, a machining center can be thought of as being a combination turret lathe and milling machine. Additional features are sometimes included by the versatility of their machines.Numerical ControlOne of the most fundamental concepts in the area of advanced manufacturing technologies is numerical control(NC). Prior to the advent of NC, all machine tools were manually operated and controlled. Among the many limitations associated with manual control machine tools, perhaps none is more prominent than limitation of operator skills. With manual control, the quality of the product is directly related to and limited to the skills of the operator. Numerical control represents the first major step away from human control of machine tools.Numerical control means the control of machine tools and other manufacturing systems through the use of prerecorded, written symbolic instructions. Rather than operating a machine tool, an NC technician tool to be numerically controlled, it must be interfaced with a device for accepting and decoding the programmed instructions, known as a reader.Numerical control was developed to overcome the limitation of humanoperators, and it has done so. Numerical control machines are more accurate than manually operated machines, they can produce parts more uniformly, they are faster, and the long-run tooling costs are lower. The development of NC led to the development of several other innovations in manufacturing technology:1.Electrical discharge machining.ser cutting.3. Electron beam welding.Numerical control has also made machines tools more versatile than their manually operated predecessors. An NC machine tool can automatically produce a wide variety of parts, each involving an assortment of widely varied and complex machining processes. Numerical control has allowed manufacturers to undertake the production of products that would not have been feasible from an economic perspective using manually controlled machine tools and processes.Like so many advanced technologies, NC was born in the laboratories of the Masschusetts Institute of Technology. The concept of NC was developed in early 1950s with funding provided by the U.S.Air force. In its earliest stages, NC machines were able to make straight cuts efficiently and effectively.However,curved paths were a problem because the machine tool had to be programmed to undertake a series of horizontal and vertical steps to produce a curve. The shorter is straight lines making up the steps, the smoother is the curve. Each line segment in the steps had to be calculated.This problem led to the development in 1959 of the Automatically Programmed Tools(APT) language. This is a special programming language for NC that uses statements similar to English language to define the part geometry, describe the cutting tool configuration, and specify the necessary motions. The development of the APT language was a major step forward in the further development of NC technology. The original NC systems were vastly different from those used today. The machines had hardwired logic circuits. This instructional programs were written on punched paper, which was later to be replaced by magnetic plastic tape. A tape reader was used to interpret the instructions written on the tape for the machine. Together, all of this represented a giant step forward in the control of machine tools. However, there were a number of problems with NC at this point in its development.A major problem wad the fragility of the punched paper tape medium. Itwas common for the paper tape containing the programmed instructions to break or tear during a machining process. This problem was exacerbated by the fact that each programmed instructions had to be return through the reader. If it was necessary to produce 100 copies of a given part,it was also necessary to run the paper tape through the reader 100 separate times. Fragile paper tapes simply could not withstand the rigors of a shop floor environment and this kind of repeated use.This led to the development of a special magnetic plastic tape. Whereas the paper tape carried the programmed instructions as a series of holes punched in the tape, the plastic tape carried the instructions as a series of magnetic dots. The plastic tape was much stronger than the paper taps, which solved the problem of frequent tearing and breakage. However, it still left two other problems.The most important of these was that it was difficult or impossible to change the instructions entered on the tape. To make even the most minor adjustments in a program of instructions, it necessary to interrupt machining operations and make a new tape. It was also still necessary to run the tape through the reader as many times as there were parts to be produced. Fortunately, computer technology became a reality and soon solved the problem of NC associated with punched paper and plastic tape.The development of a concept known as direct numerical control(DNC)solved the paper and plastic tape problems associated with numerical control by simply eliminating tape as the medium for carrying the programmed instructions. In direct numerical control machine tools are tied, via a data transmission link, to a host computer. Programs for operating the machine tools are stored in the host computer and fed to the machine tool as needed via the data transmission linkage. Direct numerical control represented a major step forward over punched tape and plastic tape. However, it is subject to the same limitations as all technologies that depend o a host computer. When the lost computer goes down, the machine tools also experience downtime. This problem led to the development of computer numerical control.The development of the microprocessor allowed for the development of programmable logic controllers(PNC)and microcomputer. These two technologies allowed for the development of computer numerical control(CNC). With CNC, each machine tool has a PLC or a microcomputer that serves the same purpose. This allows programs to be input and stored at each individual machine tool. It also allows programs to be developed off-line and download at the individual machine tool. CNC solved the problems associated with downtime of the host computer, but it introducedanother known as data management. The same program might be loaded on ten different being solved by local area networks that connect microcomputer for better data management.CNC machine tool feed motion systemsCNC machine tool feed motion systems, especially to the outline of the control of movement into the system, must be addressed to the movement into the position and velocity at the same time the realization of two aspects of automatic control, as compared with the general machine tools, require more feed system high positioning accuracy and good dynamic response. A typical closed-loop control of CNC machine tool feed system, usually by comparing the location of amplification unit, drive unit, mechanical transmission components, such as feedback and testing of several parts. Here as mechanical gear-driven source refers to the movement of the rotary table into a linear motion of the entire mechanical transmission chain, including the deceleration device, turning the lead screw nut become mobile and vice-oriented components and so on. To ensure that the CNC machine tool feed drive system, precision, sensitivity and stability, the design of the mechanical parts of the general requirement is to eliminate the gap, reducing friction, reducing the movement of inertia to improve the transmission accuracy and stiffness. In addition, the feeding system load changes in the larger, demanding response characteristics, so for the stiffness, inertia matching the requirements are very high.Linear Roller GuidesIn order to meet these requirements, the use of CNC machine tools in general low-friction transmission vice, such as anti-friction sliding rail, rail rolling and hydrostatic guideways, ball screws, etc.; transmission components to ensure accuracy, the use of pre-rational, the form of a reasonable support to enhance the stiffness of transmission; deceleration than the best choice to improve the resolution of machine tools and systems converted to the driveshaft on the reduction of inertia; as far as possible the elimination of drive space and reduce dead-zone inverse error and improve displacement precision.Linear Roller Guides outstanding advantage is seamless, and can imposepre-compression. By the rail body, the slider, ball, cage, end caps and so on. Also known as linear rolling guide unit. Use a fixed guide body without moving parts, the slider fixed on the moving parts. When the slider moves along the rail body, ball and slider in the guide of the arc between the straight and through the rolling bed cover ofRolling Road, from the work load to non-work load, and then rolling back work load, constant circulation, so as to guide and move the slider between the rolling into a ball.Bridge CraneBridge crane is having an elevated track running in a bridge-type crane, also known as the crane. Bridge Crane in the laying of the bridge on both sides along the elevated track on the vertical run, lifting trolley along the bridge laying on the track in the horizontal operation, a scope of work of a rectangle, it can take full advantage of having the space below lifting materials from the ground equipment hindered.Bridge Crane widely used in indoor warehouses, factories, wharves and open storage yard and other places. Able to carry items, stood up, lifting status, and adjust operations, mainly for the workshop, sections and steel production lines yard, etc.. Lifting capacity usually in the 10 to 100 t. Bridge crane itself for horizontal movement, the winch frame for the vertical movement of the winch suspended from the hook for vertical movement, the direction of movement of three of the crane can work. In order to prevent bridge crane driver not clear in the specific hook campaign, on the ground are equipped with lifting the general command or folder, put hook. If hanging overhead crane hoisted electromagnetic lifting plate, often operated by the drivers themselves. Bridge cranes can be divided into general overhead crane, simple girder bridge crane for bridge crane and metallurgical three.Ordinary general overhead crane from lifting trolley, having run institutions, having composed of a metal structure. Lifting up from the car and from institutions, agencies and the car running small frame consists of three parts.Lifting bodies, including the motor, brakes, reducer, and the pulley drum group. Motor through the reducer, driven rotating drum so that the wire rope around 42.50 or 42.50 down to lifting weights. Small frame is from the brackets and install or run agencies and institutions, such as car parts rack, usually welded structure.Crane running the driving mode can be divided into two categories: one category is the concentrated drive, which uses a motor-driven initiatives on both sides of the drive shaft driven wheel; were driven to another, that is, on both sides of the initiative the wheels with a motor drive. Small, medium and larger overhead crane with brake, and motor reducer combination into one of the "triple play" drive, the weight of the ordinary from the overhead crane for easy installation and adjustment, often drive the use of universal - axis.Crane normally used only four active and driven wheels, if a great weight,increase common approach to reduce wheel round pressure. When more than four wheels, must adopt a balanced hinged frame device so that the crane load evenly distributed in the wheels.Bridge metal structure from the main sorghum and sorghum-composed of the main beam is divided into single-and double-girder bridge having two categories. Single-beam bridge from the main beam and a single on both sides of the span at the end of sorghum, dual-beam bridge by the two main sorghum and sorghum-component.Liang Liang Gang and the end of the link-beam ends with wheels, for supporting an elevated bridge in the running. A main beam welding on track for the lifting trolley running. Having the structure of the main beam type is more a typical box structure, the four truss structure and fasting truss structure.Box structure can be divided into two-track box girder, partial double-track box-beam, single-bias-rail box and several main sorghum. Dual-track box girder is the extensive use of a basic form, the main beam from the upper and lower flange on both sides of the plate and vertical web composition, layout rail car in the center of the flange plates online, and its simple structure , manufacturing convenient, suitable for mass production, but larger forces.Partial tracks box-girder and partial double-track box-section of the main beam are from the upper and lower ranges flange plates and thick web of the main components, rail car in the main web layout above, the short Xiangbenna omit the stiffening plate, which tracks box-side main beam from a wide flange box instead of the main sorghum two main sorghum, respect smaller, but more complex manufacturing.4 truss-type structure from four plane truss structure into a closed space, in the general level of the surface Truss shops follow plate, light weight, rigidity, but compared with other structures, and its dimensions, creating more complex, fatigue lower intensity, has been less productive.Partial fasting truss structure similar to the main tracks box-girder from the four components of a closed steel structure, in addition to the main web for the Solid shaped beam, the other three plate in accordance with the design requirements cut into many windows, forming a no-ramps Fasting Truss, in the lower level of the surface occupied by taking truss plate, cranes and the operation of electrical equipment installed in the bridge house, lighter forces, the overall stiffness, and that in China is amore widely used type.General overhead crane used mainly driven power, the general is in the driver indoor manipulation, but also remote control. From the weight of up to 500 tons, up to 60 m span.Simple beam bridge crane known as sorghum cranes, and the structure and composition of ordinary bridge crane similar to a weight, span and speed are smaller. Bridge is the main sorghum or other steel I-beam and plate steel girder section composed of simple, hand-pull or electric hoist accompanied by gourd simple as lifting trolley car, the car usually in the word sorghum run on the next flange . Bridge can be elevated along the orbit, but also along the elevated suspension in the following orbit, such as a crane hoisted sorghum crane.Metallurgical dedicated bridge crane in the steel production process can be involved in a specific process operation, and its basic structure and general overhead crane similar, but in small vehicles are equipped with lifting the work of special agencies or devices. This feature is the work of a crane used frequently, poor, working-level higher. Dual-beam bridge crane factories on the track along the vertical direction of movement, the lateral movement and trolley movements campaign to hook work. Applied to machining and assembly shop, a metal structure workshop, mechanical workshops, metallurgy and casting workshop and warehouse type lifting work. With scores from the weight of the form, molecular weight mainly Gouqi, the denominator as vice Gouqi weight. There are five main types.Casting Crane: for the lifting of hot metal into Mixer, furnaces and molten steel into lifting equipment or continuous ingot steel ingot mould used. Sheng barrels lifting the car, a flip-sheng, deputy trolley barrels, and other auxiliary work.Tongs crane: Using tongs high temperature steel ingot will be vertically being lifted onto a deep soaking pits, or put it out the car shipped spindles.Stripper Crane: an ingot from the mandatory extrusion ingot mold. There are special small car Stripper devices, spindles Stripper under way and the shape of the model: Some Stripper crane-is attributable to suppress billets, ingots filed with the clamp module; Some of the clamp punctured ingot mould, with Ingot filed small pair of pliers.Feeding Crane: Charge will be added to the open hearth furnace. Trolley bottom of the column with the pick-and inciting material to me and it into the furnace. The main column to bypass the vertical axis rotation, pick-and rotary can swing from topto bottom. Deputy car repair furnace for such auxiliary operations.Forging Crane: to meet with hydraulic forging large workpieces. Trolley displayed on the main hook up special feeder to support and flip the workpiece; Vice car used to lift the workpiece.Dual-beam bridge crane, the biggest weight from 100 tons, the hook-and-grab, electromagnetic, metallurgical cranes, quenching crane, manual double girder bridge crane, electric hoist double girder overhead crane with the crane unit JB / T14405 "generic bridge crane" standard, the quality of products to JB/T53442 "universal overhead crane product quality grade" first-class requirements. Its structural features of starting up and running with the car running on the bridge, a metal structure for the double-girder box form. From the characteristics of the device in accordance with the classification for the hook, grab, electromagnetic and multipurpose bridge crane, mainly for the mines, factories, wharves and warehouses, and other material handling operations frequent stops, as a crane quenching equipment, a high-speed heat treatment process of decline . Metallurgical casting molten steel crane to transport packet is indispensable than smelting industrial equipment. The use of modern means of science and technology, will enable any crane structure with a jump-speed performance. Can be used with high-level rotating hook for stacking operations.Single-girder bridge crane, the largest weight of 10 tons from, hook-and-grab, electromagnetic, flying single-girder bridge crane, manual single-girder bridge crane with the crane unit JB/T1306 "electric single-girder bridge Crane "and JB/T2603" electric single-girder overhead crane hoisted the "standard requirements. Its structure is characterized manual or electric hoist monorail car along the main beam under the flange I-beam operation, material handling operations, normally used for workshops, warehouses and other material handling operations, which manual does not allow for single-girder crane No electricity or power occasions. Grab motor with the monorail or bulk materials can also be used to grab operations, the unit crane compact structure, operational flexibility, can be used to ground, can also be used to operate the cab. Special circumstances can also be used for remote operation. Industrial production or storage is indispensable equipment.Crane normal working hours to allow a lifting of the greatest quality as rated starting weight. Rated crane hook from the hook and the weight does not include the fixed pulley group themselves. Grab sucker and electromagnetic devices, such as the quality of admission included in the ratings from the weight. In accordance with thestandard provisions of the bridge crane from the weight of a series of priority number system is R10, from 3.2 t, beginning with the increment of 1.25 Gongpi 4,5,6.3,8,10,12.5,16,20,25,32, 40,50 t……. But domestic products only under the bridge crane years of production practices, from the above series of elected part of the actual composition of a series of weight. Is the most commonly used Series 5 t, 10t, 16t, 20t, 32t and 50 t. Normally, when a weight of more than 10 t, or from the establishment of two bodies, namely the lifting of lifting bodies and institutions, both from the weight of a ratio of about 1:4. Main body from the weight or, for lifting heavy cargo lifting of the weight from the small, but faster, lighter for the lifting of the goods or for supporting efforts to enhance work efficiency.Generally experienced the largest crane lifting weights to determine the starting weight,taking into account the conditions of work reproduced or process requirements. Crane does not allow the use of overloading, in the lifting of the frequent changes of the occasion, crane should consider certain margin. In some cases, the occasional object to the lifting of overweight available when two cranes coordinated operations. In the process fixed, the lifting of the weight will remain basically unchanged, the use of cranes loaded with the basic circumstances, can be lifted up from vice, to simplify the structure of a crane and lower costs. Foreign large-tonnage it is not all bridge crane with a lifting body vice, but necessary option.The use of overhead crane safety matters:(1) Each crane must be obvious from the weight rated local hang the signs.(2) Work, it was not allowed on the bridge or hook couriers.(3) No Operator's Certificate and is not allowed to drink driving cranes.(4) Operating must focus on the spirit, not talk, smoking or do not do.(5) To clean the car; while Luanfang equipment, tools, flammable materials, explosive materials and dangerous goods.(6) The cranes could be allowed to use super.(7) The following situations while lifting: bundling is not solid; mechanical overload; signal unknown; Cable; buried in the ground or frozen items; suspended on some items; no security protection measures for the flammable and explosive - and dangerous goods; drive liquid items do not meet the safe use of wire rope; fault movements institutions.(8) The cranes in the absence of obstructions on the lines running, as well as hanging hook or spreader of the base must be more than 2 m from the ground. If the。

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中英文资料翻译EXTENDING BEARING LIFEAbstract：Nature works hard to destroy bearings, but their chances of survival can be improved by following a few simple guidelines. Extreme neglect in a bearing leads to overheating and possibly seizure or, at worst, an explosion. But even a failed bearing leaves clues as to what went wrong. After a little detective work, action can be taken to avoid a repeat performance.Keywords: bearings failures lifeBearings fail for a number of reasons，but the most common are misapplication，contamination，improper lubricant，shipping or handling damage，and misalignment. The problem is often not difficult to diagnose because a failed bearing usually leaves telltale signs about what went wrong．However，while a postmortem yields good information，it is better to avoid the process altogether by specifying the bearing correctly in The first place．To do this，it is useful to review the manufacturers sizing guidelines and operating characteristics for the selected bearing.Equally critical is a study of requirements for noise, torque, and runout, as well as possible exposure to contaminants, hostile liquids, and temperature extremes. This can provide further clues as to whether a bearing is right for a job.1 Why bearings failAbout 40% of ball bearing failures are caused by contamination from dust, dirt, shavings, and corrosion. Contamination also causes torque and noise problems, and is often the result of improper handling or the application environment．Fortunately, a bearing failure caused by environment or handling contamination is preventable，and a simple visual examination can easily identify the cause．Conducting a postmortem il1ustrates what to look for on a failed or failing bearing．Then，understanding the mechanism behind the failure, such as brinelling or fatigue, helps eliminate the source of the problem.Brinelling is one type of bearing failure easily avoided by proper handing andassembly. It is characterized by indentations in the bearing raceway caused by shock loading－such as when a bearing is dropped-or incorrect assembly. Brinelling usually occurs when loads exceed the material yield point(350,000 psi in SAE 52100 chrome steel)．It may also be caused by improper assembly, Which places a load across the races．Raceway dents also produce noise，vibration，and increased torque.A similar defect is a pattern of elliptical dents caused by balls vibrating between raceways while the bearing is not turning．This problem is called false brinelling. It occurs on equipment in transit or that vibrates when not in operation. In addition, debris created by false brinelling acts like an abrasive, further contaminating the bearing. Unlike brinelling, false binelling is often indicated by a reddish color from fretting corrosion in the lubricant.False brinelling is prevented by eliminating vibration sources and keeping the bearing well lubricated. Isolation pads on the equipment or a separate foundation may be required to reduce environmental vibration. Also a light preload on the bearing helps keep the balls and raceway in tight contact. Preloading also helps prevent false brinelling during transit.Seizures can be caused by a lack of internal clearance, improper lubrication, or excessive loading. Before seizing, excessive, friction and heat softens the bearing steel. Overheated bearings often change color，usually to blue-black or straw colored．Friction also causes stress in the retainer，which can break and hasten bearing failure．Premature material fatigue is caused by a high load or excessive preload．When these conditions are unavoidable，bearing life should be carefully calculated so that a maintenance scheme can be worked out．Another solution for fighting premature fatigue is changing material．When standard bearing materials，such as 440C or SAE 52100，do not guarantee sufficient life，specialty materials can be recommended. In addition，when the problem is traced back to excessive loading，a higher capacity bearing or different configuration may be used．Creep is less common than premature fatigue．In bearings．it is caused by excessive clearance between bore and shaft that allows the bore to rotate on the shaft．Creep can be expensive because it causes damage to other components in addition to the bearing．0ther more likely creep indicators are scratches，scuff marks，or discoloration to shaft and bore．To prevent creep damage，the bearing housing and shaft fittings should be visually checked．Misalignment is related to creep in that it is mounting related．If races are misaligned or cocked．The balls track in a noncircumferencial path．The problem is incorrect mounting or tolerancing，or insufficient squareness of the bearing mounting site．Misalignment of more than 1/4·can cause an early failure．Contaminated lubricant is often more difficult to detect than misalignment or creep．Contamination shows as premature wear．Solid contaminants become an abrasive in the lubricant．In addition。

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