Lesson 32 Limits and Tolerances 机械工程专业英语教学课件

机械工程专业英语复习资料

AC=alternative current交流AGV=Automated Guided Vehicle自动导引小车AGVS= Automated Guided Vehicle System自动导引小车系统AMT=advanced manufacturing technology先进制造技术ANSI=American National Standards Institute美国国家标准协会APT=Automatically Programmed Tools自动数控程序BOM=Bill of Material物料清单CAA=Computer Aided Analysis Process计算机辅助分析过程CAD=Computer-Aided Design计算机辅助设计CADD=Computer-Aided Design Drafting计算机辅助设计制图CAE=computer aided engineering计算机辅助工程CAM=Computer-Aided Manufacturing计算机辅助制造CAIT=computer aided testing and inspection计算机辅助实验与检测CAPP=Computer Aided Process Planning计算机辅助工艺设计CHP=chemical Polishing 化学抛光CIM=Computer integrated manufacturing计算机集成制造CBN=Cubic Boron Nitride立方氮化硼CMM=Coordinate Measuring Machine三坐标测量机CNC=computer numerical control电脑数字控制DC=direct current直流DNC=Direct Numerical Control直接数字控制DOF=degrees of freedom自由度DXF=data exchange format数据交换格式ECM=Electrochemical Machining电解加工EBM=Electron beam machining电子束加工EDM=Electrical Discharge Machining电火花加工EGM= enhanced graphics module增强型图形模组FA=factory automation工厂自动化FDM=Fused Deposition Modelling熔融沉积成型FEA=Finite element analysis有限元分析FMC=flexible manufacturing component柔性制造单元FMS=Flexible Manufacturing System柔性制造系统Finite-element有限元Four-bar linkage四连杆机构GNC=graphical numerical control图形数控GT=Grease Trap润滑脂分离器HPM=hard-part machining硬态切削HSS=High-Speed-Steel高速钢IGES=initial graphic exchange specification初始图形交换规则ISO=International Standardization Organization国际标准组织IT=International Tolerance(grade)国际公差JIT=Just in Time准时生产LBM=Laser beam machining激光切削加工LED=light-emitting diode发光二级管LMC=least material condition最小实体状态LOM=Laminated Object Manufacturing叠层实体制造技术MMC=maximum material condition最大实体状态MATL=material材料MC=machining center加工中心NC=Numerical Control数字控制NMP=Nontraditional Manufacturing Processes特种加工技术PCB=printed circuit boards印刷电路板PLC=Programmable Logic Controller PLC控制PKW=parallel kinematics machine并联机床QTY=quantity required需求数量RGV=rail guided vehicle有轨自动导引小车RPM=Rapid Prototype Manufacturing快速成型技术SL= Stereo Lithography光固化成型SLA=Stereo Lithography Apparatus立体印刷技术/光固化立体造型SLS=Selective Laser Sintering选择性激光烧结USM=Ultrasonic Machining超声波加工VNC=voice numerical control声音控制WEDM=Wirecut Electrical Discharge Machining电火花线切割加工WJM/C=water-jet machining/cutting水射流切削3D PRINT 3D打印一、将下列单词译成汉语Mechanism（机械，机构，机构学）configuration（外形，构造，结构）displacement（位移）velocity（速度）acceleration（加速度）gear（齿轮）sprocket（链轮）pulley（带轮）kinematician /dynamics（运动/动力学，力学）kinematician（运动）cam凸轮camshaft凸轮轴accuracy精度dependability可靠性pulley滑轮flywheel飞轮crank曲柄sprocket链轮axle心轴spindle主轴clutche离合器brake制动shaper牛头刨床planer龙门刨pulley皮带轮flywheel飞轮spindle轴clutche离合器crank曲柄sprocket链轮axle车轴brake制动warpage配气机构coolant冷却剂二、将下列词组译成汉语kinematic chain（运动链）skeleton diagram（草图，示意图，简图）Gear system/Cam system（齿轮传动系统/凸轮系统）uniform motion/nonuniform motion（匀速运动/非匀速运动）nonlinear motion（非线性运动）kinematic analysis（运动分析）schematic diagram（运动简图）textile machinery（纺织机械）Kinematic design/ kinematic syntheses（运动设计/运动合成）machinedesign（机械设计）Gear trains/ Cam mechanisms（轮系，齿轮传动链/凸轮机构）dynamic force/inertia force/ static force（动力/惯性力/静力）relative velocity/ absolute velocity（相对速度/绝对速度）angular acceleration/ tangential acceleration/ centripetalacceleration/ velocity vector（角加速度/切向加速度/向心加速度/速度矢量）binary link/ ternary link（二杆组/三杆组）the basecircle（基圆）the pitch curve（啮合曲线）the contact force（接触力）the intermittent motion （间歇运动）the common normal（公法线）the conjugate profiles（共轭齿廓）the cycloidal profiles （摆线齿形）the involute profiles （渐开线齿形）the spurgear（直齿轮）the herringbone gears（双螺旋齿轮）the face gear（端面齿轮）the radial distance （径向距离）the addendumcircle（齿顶圆）The tooth thickness（齿厚）the tooth space（齿间隙）the cap screws（螺钉）the setscrews（固定螺丝钉）theengineering graphics（工程力学）mechanical design（机械设计）the installation techniques（安装技术）the bolted joint（螺栓连接）the hardened washers（强化垫圈）the fatigue resistance（抗疲劳强度）the modulus of elasticity（弹性模量）theantifriction bearing（减摩轴承）the rolling bearing（滚动轴承）the rolling contact （滚动接触）the sliding contact（滑动触电）the corrosion resistance（抗腐蚀性）the machining tolerances（加工公差）the fatigue loading （疲劳载荷）the radial loads（径向负荷）the thrust loads逆负荷the ball bearing球轴承the roller bearing滚子轴承the single-row bearings单沟轴承thedouble-row bearing双沟轴承the needle bearing滚针轴承the bearing life轴承寿命The rating life额定寿命the axis of rotation旋转轴The helix angle螺旋角a right-hand helix 右旋a left-hand helix左旋an involute helicoids螺旋面an involute curve渐开线theshaft centerlines轴中心线worm gear蜗轮the hypoid gear准双曲面齿轮right angle直角worm gearing蜗杆传动the lead angle导角shaftangle轴线角度bending load弯曲载荷tension load张力负荷compression load压缩负载torsional load扭转负荷the bending moment弯矩the bending stress弯曲应力the shot peening喷丸法the actuating force工作力the coefficient of friction摩擦系数Anelectromagnetic coil电磁线圈the magnetic circuit磁路the design specifications中国设计规范the industrial engineering工业工程the machining industry加工行业the machine shops机器商店machine tool机床angular displacements角位移The electric motor电机transmission Linkage传输连接the cutting force切削力the static loads静态负荷the dynamic loads动态载荷the grinding wheel砂轮lubricating oil润滑油the cutting fluids切削液protective guards防护装置the cutting tool刀具the range of feeds进给量enginelathes普通车床turret lathes六角车床the boring machine镗床the drilling machines钻床the milling machines铣床the broachingmachines绞孔机；拉床the sawing machines锯床the cylindrical grinder外圆磨床the centreless grinders无心磨床the surface grinders平面磨床the chemical milling铣削the ultrasonic machining超声波加工a toolholder刀架a compound rest复式刀架the feed screw丝杆the feed rod光杆The feed box进给箱power feed进给the full depth大切削深度thread cutting螺纹切削a chasing dial螺纹指示盘the forward stroke冲程the return stroke回程the clapper box摆动刀架thehydraulic shaper液压牛头刨床the universal machines通用机械universal joints万向节Tracer milling仿形铣the master pattern模型the acceleration of gravity重力加速度conducting material导电材料non-conducting material绝缘材料三、将下列短语译成汉语1.Plane and spatial linkages（平面和空间连杆）2.constrained kinematic chain/unconstrained kinematic chain（约束运动链/非约束运动链）3.closed-loop linkage（闭环运动链）4.four-bar linkage（四连杆机构）5.slider-crank (or crank and slider) mechanism（曲柄滑块机构）6.internal combustion engine（内燃机）7.the kinematic analysis of mechanisms（机构运动分析）8.degree of freedom of the mechanism（机构自由度）9.kinematic analysis process /kinematic synthesis process（运动分析步骤/运动合成步骤）10.input angular velocity（输入角速度）11.input angular acceleration（输入角加速度）12.automatic packaging machinery（自动包装机）13.cam-contour dimensions/cam-follower diameters（凸轮轮廓尺寸/凸轮从动件直径）14.mechanical analog computer（机构模拟计算机）15.dead-center position（死点位置）16.crank-rocker linkage/double-rocker linkage/double-crank (drag-link) linkage（曲柄摇杆机构/双摇杆机构/双曲柄机构）17.maximum force component/ resulting output force or torque（最大的力量组成/输出的最大力或力矩）18.output motion variables/input motion variable（输出运动变量/输入运动变量）19.absolute angular positions（绝对角位置）20.velocity polygon method（速度的多边形的方法）21.instantaneous center method/instant center method（瞬心法/即时瞬心法）22.inertia-force analysis of mechanisms and machines（机构和机器的惯性力分析）23.one and the same coordinate system /inertia frame of reference（惯性参考系）24.systematic design of mechanisms（机械设计的系统）25.cam-contour dimensions/cam-follower diameters（凸轮轮廓尺寸/凸轮从动件直径）26.disk or plate translating (two-dimensional or planar) 盘形传动凸轮（两维的，即平面的）27.cylindrical (three-dimensional or spatial) cams圆柱形凸轮（三维的，即空间的）机构28.a radial (in-line) translating roller follower一个对心直动滚子从动件29.a constant angular velocity ratio旋转角速度的比例30.a constant torque ratio一个恒转矩比31.Nonlinear angular velocity ratios非线性角速度比率32.the parallel helical gear平行斜齿轮33.the crossed helical gear交叉斜齿轮34.the straight bevel gear直锥齿轮35.the spiral bevel gear弧齿锥齿轮36.the skew bevel gear大角度斜交锥齿轮37.the hexagon head screws六角头螺钉38.the fillister head screws槽头螺钉39.the flat head screws 平头螺钉40.the hexagon socket head screws内六角沉头螺钉。

机械外文翻译中英文

英文资料Limits and TolerancesThe breakage of the machine spare parts ,generally always from the surface layer beginning of .The function of the product ,particularly its credibility and durable ,be decided by the quantity of spare parts surface layer to a large extent. Purpose that studies the machine to process the surface quantity be for control the machine process medium various craft factor to process the surface quantity influence of regulation, in order to make use of these regulations to control to process the process, end attain to improve the surface quantity, the exaltation product use the function of purpose .The machine processes the surface quantity to use the influence of the function to the machine(A) The surface quantity to bear to whet the sexual influence1.Rough degree of surface to bear to whet the sexual influenceA just process vice-of two contact surfaces of good friction, the first stage is rough only in the surface of the peak department contact ,the actual contact area is much smaller than theoretical contact area, in contact with each other the peak of the units have very great stress, to produce actual contact with the surface area of plastic deformation, deformation and peak between the Department of shear failure, causing serious wear.Parts wear may generally be divided into three stages, the initial stage of wear and tear, normal wear and tear all of a sudden intense phase of stage wear.Parts of the surface roughness of the surface wear big impact. In general the smaller the value of surface roughness, wear better. However, surface roughness value is too small, lubricants difficult to store, contact between the adhesive-prone elements, wear it to increase. Therefore, the surface roughness of a best value, the value and parts of the work related to increased work load, the initial wear increased, the best rough surface is also increased.2.Cold Working hardening the surface of the wear resistanceProcessing the Cold Work hardening the surface of the friction surface layer of metal microhardness increase, it will generally improve the wear resistance. Cold Working but not a higher degree of hardening, wear resistance for the better, because too much will lead to hardening of the Cold Working excessive loose organization ofmetal, even a crack and peeling off the surface of the metal, declined to wear resistance.(B)The surface quality of the impact of fatigue strengthMetal hand alternating loads of fatigue after the damage occurred in parts often Chilled layer below the surface and, therefore parts of the surface quality of fatigue very influential.1.Surface roughness on the impact of fatigue strengthIn alternating load, the surface roughness of the Au-site easily lead to stress concentration, a fatigue crack, the higher the value of surface roughness, surface traces of Yu Shen Wen, Wen at the end of the radius smaller, anti-fatigue damage at the end of the more capacity Worse.2.Residual stress, fatigue Cold Work hardening of the impactResidual stress on the impact of large parts fatigue. Surface layer of residual stress fatigue crack will expand and accelerate the fatigue damage the surface layer and the residual stress can prevent fatigue crack growth, delaying the formation of fatigue damage.(C)The surface quality of the corrosion resistance of the impactParts of the corrosion resistance to a large extent depends on the surface roughness. The higher the value of surface roughness, Au Valley accumulate on the more corrosive substances. Corrosion resistance of the more worse.Surface layer of residual stress will produce stress corrosion cracking, lower parts of the wear-resistance, and the residual stress is to prevent stress corrosion cracking.(D) The surface quality with qualityRough surface will affect the value of the size of the co-ordination with the surface quality. The gap with rough value will increase wear and tear, increased space, with the requirements of the destruction of nature. For Fit, the assembly part of the process of convex surface-crowded peak times, the actual reduction of the surplus and reduce the support of the connection between the strength.DimensioningThe design of a machine includes many factors other than those of determining the loads and stresses and selecting the proper materials. Before construction or manufacture can begin, it is necessary to have complete assembly and detail drawings to convey all necessary information to the shop men. The designer frequently is called upon to check the drawings before they are sent to the shop. Much experience andfamiliarity with manufacturing processes are needed before one can become conversant with all phases of production drawings.Drawings should be carefully checked to see that the dimensioning is done in a manner that will be most convenient and understandable to the production departments. It is obvious that a drawing should be made in such a way that it has one and only one interpretation. In particular, shop personnel should not be required to make trigonometric or other involved calculations before the production machines can be set up.Dimensioning is an involved subject and long experience is required for its mastery.Tolerances must be placed on the dimensions of a drawing to limit the permissible variations in size because it is impossible to manufacture a part exactly to a given dimension. Although small tolerances give higher quality work and a better operating mechanism, the cost of manufacture increases rapidly as the tolerances are reduced, as indicated by the typical curve of Fig 14.1. It is therefore important that the tolerances be specified at the largest values that the operating or functional considerations permit.Tolerances may be either unilateral or bilateral. In unilateral dimensioning, one tolerance is zero, and all the variations are given by the other tolerance. In bilateral dimensioning, a mean dimension is used which extends to the midpoint of the tolerance zone with equal plus and minus variations extending each way from this dimension.The development of production processes for large-volume manufacture at low cost has been largely dependent upon interchangeability of component parts. Thus the designer must determine both the proper tolerances for the individual parts, The manner of placing tolerances on drawings depends somewhat on the kind of product or type of manufacturing process. If the tolerance on a dimension is not specifically stated, the drawing should contain a blanket note which gives the value of the tolerance for such dimensions. However, some companies do not use blanket notes on the supposition that if each dimension is considered individually, wider tolerance than those called for in the note could probably be specified. In any event it is very important that a drawing be free from ambiguities and be subject only to a single interpretation.Dimension and ToleranceIn dimensioning a drawing, the numbers placed in the dimension lines represent dimension that are only approximate and do not represent any degree of accuracy unless so stated by the designer.To specify a degree of accuracy, it is necessary to add tolerance figures to the dimension. Tolerance is the amount of variation permitted in the part or the total variation allowed in a given dimension. A shaft might have a nominal size of 2.5 in. (63.5mm), but for practical reasons this figure could not be maintained in manufacturing without great cost. Hence, a certain tolerance would be added and , if a variation of ±0.003 in.(±0.08mm) could be permitted, the dimension would be stated 2.500±0.003(63.5±0.008mm).Dimensions given close tolerances mean that the part must fit properly with some other part. Both must be given tolerances in keeping with the allowance desired, the manufacturing processes available, and the minimum cost of production and assembly that will maximize profit. Generally speaking, the cost of a part goes up as the tolerance is decreased. If a part has several or more surfaces to be machined, the cost can be excessive when little deviation is allowed from the nominal size.Allowance, which is sometimes confused with tolerance, has an altogether different meaning.It is the minimum clearance space intended between mating parts and representsthe condition of tightest permissible fit. If a shaft, size 1.4980.0000.003+-, is to fit a hole ofsize 1.5000.0030.000+-, the minimum size hole is 1.500 and the maximum size shaft is 1.498.Thus the allowance is 0.002 and the maximum clearance is 0.008 as based on the minimum shaft size and maximum hole dimension.Tolerances may be either unilateral or bilateral. Unilateral tolerance means that any variation is made in only one direction from the nominal or basic dimension.Referring to the previous example, the hole is dimensioned 1.5000.0030.000+-, whichrepresents a unilateral tolerance. If the dimensions were given as 1.500±0.003, the tolerance would be bilateral; that is , it would vary both over and under the nominal dimension. The unilateral system permits changing the tolerance while still retaining the same allowance or type of fit. With the bilateral system, this is not possible without also changing the nominal size dimension of one or both of the two mating parts. In mass production, where mating parts must be interchangeable, unilateral tolerances are customary. To have an interference or fore fit between mating parts, the tolerances must be such as to create a zero or negative allowance.Tolerances Limits and FitsThe drawing must be a true and complete statement of the designer’s expr essed in such a way that the part is convenient to manufacture. Every dimension necessary to define the product must be stated once and repeated in different views. Dimensions relating to one particular feature, such as the position and size of hole, where possible, appear on the same view.There should be no more dimensions than are absolutely necessary, and no feature should be located by more than one dimension in any direction. It may be necessary occasionally to give an auxiliary dimension for reference, possibly for inspection. When this is so, the dimension should be enclosed in a bracket and marked for reference. Such dimensions are not governed by general tolerances.Dimensions that affect the function of the part should always be specified and not left as the sum or other dimensions. If this is not done, the total permissible variation on that dimension will form the sum or difference of the other dimensions and their tolerance, and this with result in these tolerances having to be made unnecessarily tight. The overall dimension should always appear.All dimensions must be governed by the general tolerance on the drawing unless otherwise stated. Usually, such a tolerance will be governed by the magnitude of the dimension. Specific tolerances must always be stated on dimensions affecting or interchangeability.A system of tolerances is necessary to allow for the variations in accuracy that are bound to occur during manufacture, and still provide for interchangeability and correct function of the part.A tolerance is the difference in a dimension in order to allow for unavoidable imperfections in workmanship. The tolerance range will depend on the accuracy of the manufacturing organization, the machining process and the magnitude of the dimension. The greater the tolerance range is disposed on both sides of the nominal dimension. A unilateral tolerance is one where the tolerance zone is on one side only of the nominal dimension, in which case the nominal dimension may from one of the limits.Limits are the extreme dimensions of the tolerance zone. For example, nominal dimension30mm tolerance 30.0230.000++ limits 30.02530.000Fits depend on the relationship between the tolerance zones of two mating parts,and may be broadly classified into a clearance fit with positive allowance, a transition fit where the allowance may be either positive or negative (clearance or interference) , an interference fit where the allowance is always negative.Type of Limits and FitsThe ISO system of Limits and Fits, widely used in a number of leading metric countries, is considerably more complex than the ANSI system.In this system, each part has a basic size. Each limit of part, high and sign being obtained by subtracting the basic size form the limit in question. The difference between the two limits of size of a part is called the tolerance, an absolute without sign.There are three classes of fits: 1) clearance fits, 2) transition fits ( the assembly may have either clearance or interference ), and 3) interference fits .Either a shaft-basis system or a hole-basis system may be used. For any given basic size, a range of tolerance and deviations may be specified with respect to be line of zero deviation, called the zero line. The tolerance is a function of the basic size and is designated by a number symbol, called the grade-thus the tolerance grade. The position of the tolerance with respect to the zero line also a function of the basic size-is indicated by a letter symbol(or two letter), a capital letter for holes and a lowercase letter for shafts. Thus the specification for a hole and shaft having a basic size of 45mm might be45H8/g7.Twenty standard grades of tolerance are provided, called IT 01,IT 0 ,IT 1-18, providing numerical values for each nominal diameter, in arbitrary steps up to 500mm (for example 0-3,3-6,6-10…, 400-500mm). The value of the tolerance unit, I, for grades 5-16 is=+0.0.001i DWhere i is in microns and D in millimeters.Standard shaft and hole deviations similarly are provided by sets of formulas, However, for practical, both tolerances and deviations are provided in three sets of rather complex tables. Additional tables gives the values for basic sizes above 500mm and for “Commonly Used Shafts and Holes” in two categories ---“General Purpose” and “Fine Mecbanisms and Horology”.中文翻译极限与误差机械零件的破坏，一般总是从表层开始的。

机械工程专业英语教程第2版Lesson 2

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Rotary Motion. The motion that is commonly transmitted is rotary motion. This type of motion may be produced with hand tools or power tools. Rotary motion is required to drill holes, turn parts in a lathe, mill surfaces, or drive a generator or fan belt.[4] 4. rotary motion 意为“回转运动”。全句可译为：钻孔、在车床上车削零件、铣平面、驱动发电机或风扇的带等都需要回转运动。
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Harmonic and Intermittent Motion.[6] Any simple vibration, such as the regular back-and-forth movement of the end of a pendulum, is simple harmonic motion.[7] 6. harmonic and intermittent motion 意为谐和运动和间歇运动”。 7. simple harmonic motion 意为“简谐运动”。全句可译为：任何简单的振动，例如摆的下端有规律的往复运动是简谐运动。
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Rectilinear Motion. The feed of a tool on a lathe, the cutting of steel on a power saw, or the shaping of materials are all situations in which rectilinear or straight line motion produces work. In each of these situations a part or mechanism is used to change rotary motion to straight line motion. The screw of a micrometer and the threads in a nut are still other applications where the direction of motion is changed from rotary to rectilinear.[5] 5. the screw of a micrometer 意为“千分尺中的螺杆”全句可译为：千分尺中的螺杆和螺母中的螺纹是把运动方向从转动变为直线的另外一些应用实例。

应用翻译---科技文体翻译练习

What Is a SketchThe mechanic must not only know how to read the language of the industrial world but must also know how to write it. He must be able to give his own ideas and describe an object to someone else. It is often necessary to make just a part for a machine. However, there is no time to make a drawing of it with instruments, no time either for a draughtsman to make a drawing. Sometimes only one piece of a machine part is to be made and, therefore, it would be inconvenient to have the draughtsman make a mechanical drawing.Sketches are important because they show ideas and dimensions of a machine part. The cleverest idea, however, may result in a great mistake if the sketch is poorly done. We must learn to make clean sketches to be easily read by others as well as by ourselves.Machine ElementsA machine consists of a number of machine elements. The most useful machine element in power transmission is the gear. The gear is virtually a wheel with a number of teeth. Gears must work in pairs. A pair of gears with different number of teeth will increase or decrease the speed of rotationPulleys and belts are very common in power transmission. They can also change speeds on machine tools. Gears or pulleys rotate on shafts. Theshaft must rest in bearings. Sometimes there may be couplings between shafts. We may use clutches to start or stop shaft motion.Some machine elements may be very large. Others may be very small. However, each of them plays a part in the construction of a machine.Cutting ToolsThe metal cutting tool separates chips from the workpiece in order to cut the part to the desired shape and size. There is a great variety of metal cutting tools. Each of them is designed to perform a particular job or a group of metal cutting operations in an efficient manner. For example, a twist drill is designed to drill a hole which has a particular size, while a turning tool may be used to turn a variety of cylindrical shapes.There are three basic types of metal cutting tools: single-point tools, multiple-point tools, and abrasives. A single-point metal cutting tool has a single cutting edge and is used for turning, boring, shaping, and planning. The most common machine tool that employs the single-point cutting tool is the engine lathe. Multiple-point tools have two or more cutting edges such as drills, reamers, and milling cutters. The cutting edge is that part of the tool where cutting is actually done. Grinding wheels are an example of abrasive cutting tools. Each grinding wheel hasa lot of abrasive grains which act as very small cutting tools.Limits and TolerancesMachine parts are manufactured so they areinterchangeable. In other words, each part of a machineor mechanism is made to a certain size and shape so itwill fit into any other machine or mechanism of the same type. To make the part interchangeable, each individual part must be made to a size that will fit the mating part inthe correct way. It is not only impossible, but alsoimpractical to make many parts to an exact size. This isbecause machines are not perfect, and the tools becomeworn. A slight variation from the exact size is alwaysallowed. The amount of this variation depends on the kindof part being manufactured. For example, a part might bemade 6 inches long with a variation allowed of 0.003( three thousandths ) inches above and below this size.Therefore the part could be 5.997 to 6.003 inches and stillbe the correct size. These are known as the limits. Thedifference between upper and lower limits is called the tolerance.When the tolerance is in both directions from the basic size, it is known as a bilateral tolerance ( plus and minus ). Sometimes the limit is allowed in only one direction. This is known as unilateral tolerance. For example, a hole may have to be 2 inches minus 0.000 inches, or plus 0.005 inches. This means that the hole must not be smaller than 2 inches, but can be as large as 2.005 inches.Surface FinishWithin recent years a great deal of attention has been given to the invesigation of the surface texture produced by various machining and finish operations, and, although we have not yet reached the stage when surface finish requirements can be specified and produced just as it is possible for a given dimension, information is being built up which may in the end bring this about.If a machine surface is reproduced to a large enough magnification it will be found to have a wevy profile, the character and shape of the waves varying for different machining methods. Equipment is now available which will produce an enlarged contour of a surface by traversing a needle-like probe over it, the instrument at the same time plotting on a chart a greatly magnified reproduction of the up-and-down movement of the probe with its longitudinal traverse.。

机械工程专业英语Unit 14

the mating parts. 大规模低成本制造生产工艺的发展很大程度取决于组成零件的互换
性。因此设计者必须确定单个零件的合适公差以及配合零件装配允许的正确间隙或过盈量。
2. Dimension and Tolerance 尺寸和公差
➢ Tolerance is the amount of variation permitted in the part or the total variation allowed in a given dimension. 公差是零件允许的变动量或给定尺寸允许的总变动。
Unit 14 Limits and Tolerances
极限与公差
1. Dimensioning 标注尺寸 2. Dimension and Tolerance 尺寸和公差 3. Tolerances Limits and Fits 公差、极限和配合 4. Type of Limits and Fits 极限和配合的类型
➢ Tolerances may be either unilateral [单边的] or bilateral [双边的].公差可以是单向的也可以是双向的。
Unilateral tolerance means that any variation is made in only one direction from the nominal or basic dimension. 单向公差意味着任何变动都是只ห้องสมุดไป่ตู้名义或基本尺寸出发向一个方向变动的。
1.500 0.003
Bilateral tolerance means
that the tolerance would
vary both over and under the nominal dimension. 它可以在名义尺寸之上或之下变化。

机械工程专业英语参考译文

机械工程专业英语》参考译文高等学校机械设计制造及其自动化专业新编系列教材(供教师及学生使用)黄运尧黄威司徒忠李翠琼武汉理工大学出版社目录编译者的话………………………………第1章材料和热加工…………………第1课机械学的基本概念…………第2课塑性理论的基本假设………第3课有限元优化的应用…………第4课金属…………………………第5课金属和非金属材料…………第6课塑料和其他材料……………第7课模具的寿命和失效…………第8踩冷加工和热加工……………第9踩铸造…………………………第10课制造中的金属成形工艺…第11课缎选………………………第12课锻造的优点和工作原理…第13课焊接………………………第14课热处理……………………第二章机构和机器原理……………。

第15课机构介绍…………………。

第16课运动分析…………………．第l7课运动的综合………………—第18课凸轮和齿轮………………—第19课螺纹件，紧固件和联接件—第20课减(耐)摩擦轴承…………＊第2l课斜齿轮、蜗杆蜗轮和锥齿轮第22课轴、离合器和制动器……—第三章机床………第23课机床基础第24课车床……第25课牛头刨、钻床和铣床…………第36课磨床和特种金属加工工艺……第四章切削技术和液压“………………第27课加工基础………………………第28课基本的机械加工参数…………第29课切削参数的改变对温度的影响第30课刀具的磨损…………第31课表面稍整加工机理…第32课极限和公差…………“第33课尺寸控制和表面桔整”第34课自动央具设计………“第36课变速液压装置……………—…………—策37课电液伺服系统…………。

……………。

第五章机械电子技术………………………………第38课专家系统……。

…………………………第3D课建筑机器人………………………………第40课微机为基础的机器人模拟………………第41课机器人学的定义和机器入系统…………第42课微型计算机基础(1)……………………第43课微型计算机基础(x)……………………第44课可编程控制器……………………………第45课CAD／CAM计算机辅助设计与制造…第46课计算机数控和直接数控，CNC和DNC第47课加工过程的数控—………………………第48课柔性制造系统……………—……………第仍课交互式编程系统…………………………第50课在振动分析方面的计算机技术…………策51课压力传感器………………………………第52课反馈元件…………………—……………第53课现代按制理论概述………………………第54课管理上采取了新的措施—来自福持汽第六章英文科技文献和专利文献的查阅…………6．1 常见科技文献及其查阅………………………6．2 专利文献概述…………………………………第七章英文科拉论文写作…………………………7．1 标题与摘要写法………………………………7．2 正文(body)的组织与写法…………………7．3 致谢、附录及参考文献………………—……参考文献………………………………………………第1章材料和热加工机械学的基本概念功是力乘以该力作用在物体上佼物体移动的距离。

(完整版)机械工程专业英语

Lesson11、the branch of scientific analysis, which deals with motions, time, and forces, is called mechanics and is made up of two parts, statics and dynamics. Statics deals with the analysis of stationary systems, i.e., those in which time is not a factor, and dynamics deals with systems, which change with time.对运动时间和作用力作出科学分析的分支成为力学。

他由静力学和动力学两部分组成。

静力学对静止系统进行分析，即在其中不考虑时间这个引述，动力学对事件而变化的系统进行分析。

2、Any two such forces acting on a body constitute a couple. The arm of the couple is the perpendicular distance between their lines of action, and the plane of the couple is the plane containing the two lines of action.作用在一个刚体上的两个这样的的里构成一个力偶。

力偶臂是这两个条作用线之间的垂直距离，力偶面是包含着两条作用线的平面。

3、Mechanics deal with two kinds of quantities: scalars and vectors. Scalar quantities are those with which a magnitude alone is associated. Examples of scalar quantities in mechanics are time, volume, density, speed, energy, and mass. Vector quantities, on the other hand, possess direction as well as magnitude. Examples of vectors are displacement, velocity, acceleration, force, moment, and momentum.力学涉及两种类型的量，标量和矢量。

机械行业英语版

一单位1、What is the difference——cans. 合金与纯金属的区别是什么？纯金属是在元素周期表中占据特定位置的元素。

例如电线中的铜和制造烹饪箔及饮料罐的铝。

Alloys contain ——gold and nickel.合金包罗不止一种金属元素。

合金的性质能通过改变其中存在的元素而改变。

金属合金的例子有：不锈钢是一种铁、镍、铬的合金，以及金饰品通常含有金镍合金。

2、Why——mass-to-volume ratio. 为什么要使用金属和合金？许多金属和合金具有高密度，因此被用在需要较高质量体积比的场所。

Some metal ——are durable.某些金属合金，例如铝基合金，其密度低，可用于航空航天以节约燃料。

许多合金还具有高断裂韧性，这意味着它们能经得起打击并且是耐用的。

3、The atomic bonding ——electrical wires. 金属的原子连结对它们的特性也有影响。

在金属内部，原子的外层阶电子由所有原子共享并能随处自由移动。

由于电子能导热和导电，所以用金属可以制造好的烹饪锅和电线。

It is impossible ——pass through.因为这些阶电子吸收到达金属的光子，所以透过金属不可能看得见。

没有光子能通过金属。

4、Some of —resistance.高熔点、低密度、高强度、高刚度、高硬度、高耐磨性和抗腐化性是陶瓷和玻璃的一些有用特性。

Many ceramics —brittle.许多陶瓷都是电和热的良绝缘体。

某些陶瓷还具有一些特殊性能：有些是磁性质料，有些是压电质料，另有些特殊陶瓷在极低温度下是超导体。

陶瓷和玻璃都有一个主要的缺点：它们容易破碎。

5、An optical fiber —damage. 光导纤维有三层：焦点由高纯度玻璃制成，该玻璃是高折射指数光传输质料；中间层为低折射指数玻璃，是掩护焦点玻璃外貌不被擦伤和完整性不被破坏的所谓覆层，外层是聚合物护套，用于掩护光导纤维不受损。

Lesson 31 Dimensional tolerances and surface roughness尺寸公差与表面粗糙度机械专业专业英语教学用书

A comprehensive study（全面、深入地研究）of the principles of interchangeability is essential for a thorough understanding and full appreciation（充分理解和正确认识）of low-cost production techniques. Interchangeability is the key to successful production regardless of quantity（任何数量）. ……
不太难看,可以用于非关键零件的 31 Dimensional tolerances and surface roughness尺寸公差与表面粗糙度
0.2um The finish is used for the interior surface of hydraulic struts（液压支柱的内表面）, for hydraulic cylinders, pistons and piston rods for O-ring packings（液压缸,O型密封圈的活塞和活塞杆）, for journals（轴颈）operating in plain bearings, for cam faces, and for rolls of antifriction bearings（滚动轴承中的滚柱）when loads are normal.
Lesson 31 Dimensional tolerances and surface roughness尺寸公差与表面粗糙度
Eliminate fixturing（固定） and handling（装卸）problems. Design for ease of locating (定位), setting up, and holding （定位、夹持与装卸）parts.

机械工程英语第二版叶邦彦教材词汇

Unit 1Advanced Engineering MaterialsCeramic 陶瓷Organic 有机的Inorganic 无机的Composite 复合材料Lubricant 润滑剂Alloy 合金Conuctivity 传导性Stiffness 刚度Ductility 韧性Cobalt 钴Nickel 镍Aluminum 铝Beverange 饮料Chromium 铬Impact 撞击力Polymer 聚合材料Atom 原子Atomic 原子的Magnisum 镁Flaw 裂纹Nick 刻痕Dent 压痕Shatter 毁损Crumple 皱折Valence 化合价Fracture toughness 断裂韧性Be grouped 归类Be divided into 划分Plastic deformation 塑性变形Be subdivided into 细分，再分Separate …into…分开，分类Unit2Heat Treatment of MetalsHardening 淬火Carbide 硬质合金Preliminary 初步的Specimen 样品Microscopic 显微镜的Rate 速率Flow 流动Exterior 外部Interior 内部Definite 确切的Uniform 一致的Eliminate 排除Warp 变形，扭曲Crack 开裂Partially 部分的Eutectoid 共析的Pearlite 珠光体Cementite 渗碳体Anneal 退火Medium 媒介Brine 盐水Finite 有限的Drawing 轧制Tensile 可拉长的Martensite 马氏体Precipitation 析出、沉淀Agglomeration 凝聚Coalescence 联合，聚并Substantial 大量的Austempering 奥氏回火法Martempering 马氏回火法Critical range 临界范围，临界期Heat quench 热淬火All the more 更加Close control 精确控制Unit 3 CastingProcessesBronze 青铜Brass 黄铜Molten 熔铸的Synthetic 合成的，人造的Pattern 模子Sprue 浇注口Runner 浇道Approximate 近似的Duplicate 复制品Aggregate 集合，总计Flask 沙箱Core 型芯Riser 冒口V oid 空隙Shrink 收缩Cope 上箱Drag 下箱Facilitate 使便利Draft 拔模余量Angular 有角度的Offset 偏移Vertical 垂直的Minimum 最小值Horizontal 水平的Portion 部分Gateway浇口Vent 通气孔Contraction 收缩Linear 线性的Shrinkage 缩水，收缩Sand casting 砂型铸造Core print 型芯头Parting line 分型线Parting face 分型面Machining（finish）allowance加工余量Unit4 2ForgingProcessescomprehensive 有压力的comprise 包含anvil 铁砧semimechanized 半机械化的elongation 拉伸lateral 横向的upsetting 顶锻bar 棒料axially 轴向的complexity 复杂性giant 巨大的hydraulically 液压的marine 航海的，船舶的propeller 螺旋推进器shaft 轴squeeze 挤，压榨ingot 锭铁refine 精炼randomly 随便地，未加计划地oriented 导向的，使适应，使确定方向porosity 多孔性hot-forming 热成型open-die forging 开模锻造close-die forging 闭模锻造jet-aircraft 喷气式飞机marine propeller shaft 螺旋桨轴drop-forge 冲锻，落锤锻造be oriented in 定……的方位Unit 5 Power Metallurgysinter 烧结coalesce 熔合ferrous 铁的，含铁的resultant 因而发生的，必然产生的homogeneous 同类的，相似的，均一的compromise 折衷的blend 混合glue 胶水theoretical 理论上的segregation 隔离diffusion 扩散，传播article 物品fabrication 编造，虚构捏造，伪造whilst 同时，时时bush 衬套bearing 轴承ferrous and nonferrousmetals 黑色及有色金属bush type bearing 滑动轴承a mass of 一堆，块，大量，大批，众多Unit 6 InjectionMoldingresin 树脂woven 机织织物mat 席子molecule 分子entity 实体，机构analogy 类似，类推，模拟，比喻differentiate 区别，区分thermoset 热固性incident 入射光opaque 不透明的solvent 溶剂fatigue 疲劳polycarbonate 聚碳酸酯transparent 透明的abrasive 研磨剂qualitatively 定性地beam 横梁specimen 样本deflection 挠度，偏差chamical bond 化学键impact strength 冲击强度incident light 入射光short-chopped fiber短纤维Unit 7 Metal Cuttingnormal 垂直的rake条，货架clearance 间隙，裕量backup 阻塞dissipation 消散rub 摩擦severe 严重的, 剧烈的adjacent 邻近的revolution 周期stroke 冲程，行程schematically 用图示法地elastically 有弹性地shear 剪切considerable 不可忽视的，相当大的curvature 弯曲，曲率rake angle 前角rake face 前刀面mild steel 中碳钢clearance angle 后角flank face 后刀面feed rate 进给量chip curl 切屑螺旋Unit 8 Grindingabrasive 有研磨作用的cylindrical 圆柱的spindle 转轴horizontal水平的vertical 竖直的planer 刨床reciprocating 往复式table 工作台periphery 圆周，边缘fixture 工件夹具chuck 吸盘center 顶尖transverse 横向的longitudinal 纵向的strap n.带, 皮带；vt. (用皮带)捆扎damp 夹紧，夹住planetary 行星的spin 使转动tilt 倾斜的resolve 分解parallel 平行的milling cutter 铣刀cylindrical surface 柱面cylindrical grinding machine 外圆磨床strap clamp 压板cylindrical grinding外圆磨削internal grinding 内圆磨削depth of cut 背吃刀量plunge cut 切入磨削rest blade 托板rubber-bonded 橡胶胶合Unit 9 Lappingand Polishinglapping 研磨polishing 抛光lap 研具embedded 压入的slurry 悬浮液piston 活塞cylinder 汽缸peak 凸峰valley 凹陷scratch 划痕pit 凹坑，蚀坑plateau 平台，高原spherical 球面的curvy 弯曲的lustrous 有光泽的mechanism 机构，机械装置smear 磨平，抹平electropolishing 电解抛光electroplating 电镀ion 离子electrolysis 电解electrolyte 电解质，电解液anodic 阳极的catholic 阴极的dissolution 溶解，融化fabrication 制造，生产，加工wafer 薄板resilient 有回弹力的reagent 试剂silicon 硅multiphase 多方面的dynamic 动力desorption解吸附作用compositive 合成的cast iron 生铁，铸铁，machining mark 机械加工痕迹surface irregularity 表面不平度mountain ranges 山脉ground down 碾碎glass lenses 玻璃透镜fine scale 精密标度mirror-like 镜似的finishing techniques 加工技巧direct electrical current 直流电metallic salt 金属盐类chemical mechanical polishing化学机械抛光damage-free 不受损伤integrated circuit 集成电路active compound 有效成分oxidation-reductive 氧化还原的Unit10 Surface。

机械专业毕业设计外文翻译--极限与误差

英文资料Limits and TolerancesThe breakage of the machine spare parts ,generally always from the surface layer beginning of .The function of the product ,particularly its credibility and durable ,be decided by the quantity of spare parts surface layer to a large extent. Purpose that studies the machine to process the surface quantity be for control the machine process medium various craft factor to process the surface quantity influence of regulation, in order to make use of these regulations to control to process the process, end attain to improve the surface quantity, the exaltation product use the function of purpose .The machine processes the surface quantity to use the influence of the function to the machine(A) The surface quantity to bear to whet the sexual influence1.Rough degree of surface to bear to whet the sexual influenceA just process vice-of two contact surfaces of good friction, the first stage is rough only in the surface of the peak department contact ,the actual contact area is much smaller than theoretical contact area, in contact with each other the peak of the units have very great stress, to produce actual contact with the surface area of plastic deformation, deformation and peak between the Department of shear failure, causing serious wear.Parts wear may generally be divided into three stages, the initial stage of wear and tear, normal wear and tear all of a sudden intense phase of stage wear.Parts of the surface roughness of the surface wear big impact. In general the smaller the value of surface roughness, wear better. However, surface roughness value is too small, lubricants difficult to store, contact between the adhesive-prone elements, wear it to increase. Therefore, the surface roughness of a best value, the value and parts of the work related to increased work load, the initial wear increased, the best rough surface is also increased.2.Cold Working hardening the surface of the wear resistanceProcessing the Cold Work hardening the surface of the friction surface layer of metal microhardness increase, it will generally improve the wear resistance. Cold Working but not a higher degree of hardening, wear resistance for the better, because too much will lead to hardening of the Cold Working excessive loose organization ofmetal, even a crack and peeling off the surface of the metal, declined to wear resistance.(B)The surface quality of the impact of fatigue strengthMetal hand alternating loads of fatigue after the damage occurred in parts often Chilled layer below the surface and, therefore parts of the surface quality of fatigue very influential.1.Surface roughness on the impact of fatigue strengthIn alternating load, the surface roughness of the Au-site easily lead to stress concentration, a fatigue crack, the higher the value of surface roughness, surface traces of Yu Shen Wen, Wen at the end of the radius smaller, anti-fatigue damage at the end of the more capacity Worse.2.Residual stress, fatigue Cold Work hardening of the impactResidual stress on the impact of large parts fatigue. Surface layer of residual stress fatigue crack will expand and accelerate the fatigue damage the surface layer and the residual stress can prevent fatigue crack growth, delaying the formation of fatigue damage.(C)The surface quality of the corrosion resistance of the impactParts of the corrosion resistance to a large extent depends on the surface roughness. The higher the value of surface roughness, Au Valley accumulate on the more corrosive substances. Corrosion resistance of the more worse.Surface layer of residual stress will produce stress corrosion cracking, lower parts of the wear-resistance, and the residual stress is to prevent stress corrosion cracking.(D) The surface quality with qualityRough surface will affect the value of the size of the co-ordination with the surface quality. The gap with rough value will increase wear and tear, increased space, with the requirements of the destruction of nature. For Fit, the assembly part of the process of convex surface-crowded peak times, the actual reduction of the surplus and reduce the support of the connection between the strength.DimensioningThe design of a machine includes many factors other than those of determining the loads and stresses and selecting the proper materials. Before construction or manufacture can begin, it is necessary to have complete assembly and detail drawings to convey all necessary information to the shop men. The designer frequently is called upon to check the drawings before they are sent to the shop. Much experience andfamiliarity with manufacturing processes are needed before one can become conversant with all phases of production drawings.Drawings should be carefully checked to see that the dimensioning is done in a manner that will be most convenient and understandable to the production departments. It is obvious that a drawing should be made in such a way that it has one and only one interpretation. In particular, shop personnel should not be required to make trigonometric or other involved calculations before the production machines can be set up.Dimensioning is an involved subject and long experience is required for its mastery.Tolerances must be placed on the dimensions of a drawing to limit the permissible variations in size because it is impossible to manufacture a part exactly to a given dimension. Although small tolerances give higher quality work and a better operating mechanism, the cost of manufacture increases rapidly as the tolerances are reduced, as indicated by the typical curve of Fig 14.1. It is therefore important that the tolerances be specified at the largest values that the operating or functional considerations permit.Tolerances may be either unilateral or bilateral. In unilateral dimensioning, one tolerance is zero, and all the variations are given by the other tolerance. In bilateral dimensioning, a mean dimension is used which extends to the midpoint of the tolerance zone with equal plus and minus variations extending each way from this dimension.The development of production processes for large-volume manufacture at low cost has been largely dependent upon interchangeability of component parts. Thus the designer must determine both the proper tolerances for the individual parts, The manner of placing tolerances on drawings depends somewhat on the kind of product or type of manufacturing process. If the tolerance on a dimension is not specifically stated, the drawing should contain a blanket note which gives the value of the tolerance for such dimensions. However, some companies do not use blanket notes on the supposition that if each dimension is considered individually, wider tolerance than those called for in the note could probably be specified. In any event it is very important that a drawing be free from ambiguities and be subject only to a single interpretation.Dimension and ToleranceIn dimensioning a drawing, the numbers placed in the dimension lines represent dimension that are only approximate and do not represent any degree of accuracy unless so stated by the designer.To specify a degree of accuracy, it is necessary to add tolerance figures to the dimension. Tolerance is the amount of variation permitted in the part or the total variation allowed in a given dimension. A shaft might have a nominal size of 2.5 in. (63.5mm), but for practical reasons this figure could not be maintained in manufacturing without great cost. Hence, a certain tolerance would be added and , if a variation of ±0.003 in.(±0.08mm) could be permitted, the dimension would be stated 2.500±0.003(63.5±0.008mm).Dimensions given close tolerances mean that the part must fit properly with some other part. Both must be given tolerances in keeping with the allowance desired, the manufacturing processes available, and the minimum cost of production and assembly that will maximize profit. Generally speaking, the cost of a part goes up as the tolerance is decreased. If a part has several or more surfaces to be machined, the cost can be excessive when little deviation is allowed from the nominal size.Allowance, which is sometimes confused with tolerance, has an altogether different meaning.It is the minimum clearance space intended between mating parts and representsthe condition of tightest permissible fit. If a shaft, size 1.4980.0000.003+-, is to fit a hole ofsize 1.5000.0030.000+-, the minimum size hole is 1.500 and the maximum size shaft is 1.498.Thus the allowance is 0.002 and the maximum clearance is 0.008 as based on the minimum shaft size and maximum hole dimension.Tolerances may be either unilateral or bilateral. Unilateral tolerance means that any variation is made in only one direction from the nominal or basic dimension.Referring to the previous example, the hole is dimensioned 1.5000.0030.000+-, whichrepresents a unilateral tolerance. If the dimensions were given as 1.500±0.003, the tolerance would be bilateral; that is , it would vary both over and under the nominal dimension. The unilateral system permits changing the tolerance while still retaining the same allowance or type of fit. With the bilateral system, this is not possible without also changing the nominal size dimension of one or both of the two mating parts. In mass production, where mating parts must be interchangeable, unilateral tolerances are customary. To have an interference or fore fit between mating parts, the tolerances must be such as to create a zero or negative allowance.Tolerances Limits and FitsThe drawing must be a true and complete statement of the designer’s expr essed in such a way that the part is convenient to manufacture. Every dimension necessary to define the product must be stated once and repeated in different views. Dimensions relating to one particular feature, such as the position and size of hole, where possible, appear on the same view.There should be no more dimensions than are absolutely necessary, and no feature should be located by more than one dimension in any direction. It may be necessary occasionally to give an auxiliary dimension for reference, possibly for inspection. When this is so, the dimension should be enclosed in a bracket and marked for reference. Such dimensions are not governed by general tolerances.Dimensions that affect the function of the part should always be specified and not left as the sum or other dimensions. If this is not done, the total permissible variation on that dimension will form the sum or difference of the other dimensions and their tolerance, and this with result in these tolerances having to be made unnecessarily tight. The overall dimension should always appear.All dimensions must be governed by the general tolerance on the drawing unless otherwise stated. Usually, such a tolerance will be governed by the magnitude of the dimension. Specific tolerances must always be stated on dimensions affecting or interchangeability.A system of tolerances is necessary to allow for the variations in accuracy that are bound to occur during manufacture, and still provide for interchangeability and correct function of the part.A tolerance is the difference in a dimension in order to allow for unavoidable imperfections in workmanship. The tolerance range will depend on the accuracy of the manufacturing organization, the machining process and the magnitude of the dimension. The greater the tolerance range is disposed on both sides of the nominal dimension. A unilateral tolerance is one where the tolerance zone is on one side only of the nominal dimension, in which case the nominal dimension may from one of the limits.Limits are the extreme dimensions of the tolerance zone. For example, nominal dimension30mm tolerance 30.0230.000++ limits 30.02530.000Fits depend on the relationship between the tolerance zones of two mating parts,and may be broadly classified into a clearance fit with positive allowance, a transition fit where the allowance may be either positive or negative (clearance or interference) , an interference fit where the allowance is always negative.Type of Limits and FitsThe ISO system of Limits and Fits, widely used in a number of leading metric countries, is considerably more complex than the ANSI system.In this system, each part has a basic size. Each limit of part, high and sign being obtained by subtracting the basic size form the limit in question. The difference between the two limits of size of a part is called the tolerance, an absolute without sign.There are three classes of fits: 1) clearance fits, 2) transition fits ( the assembly may have either clearance or interference ), and 3) interference fits .Either a shaft-basis system or a hole-basis system may be used. For any given basic size, a range of tolerance and deviations may be specified with respect to be line of zero deviation, called the zero line. The tolerance is a function of the basic size and is designated by a number symbol, called the grade-thus the tolerance grade. The position of the tolerance with respect to the zero line also a function of the basic size-is indicated by a letter symbol(or two letter), a capital letter for holes and a lowercase letter for shafts. Thus the specification for a hole and shaft having a basic size of 45mm might be45H8/g7.Twenty standard grades of tolerance are provided, called IT 01,IT 0 ,IT 1-18, providing numerical values for each nominal diameter, in arbitrary steps up to 500mm (for example 0-3,3-6,6-10…, 400-500mm). The value of the tolerance unit, I, for grades 5-16 is=+0.0.001i DWhere i is in microns and D in millimeters.Standard shaft and hole deviations similarly are provided by sets of formulas, However, for practical, both tolerances and deviations are provided in three sets of rather complex tables. Additional tables gives the values for basic sizes above 500mm and for “Commonly Used Shafts and Holes” in two categories ---“General Purpose” and “Fine Mecbanisms and Horology”.中文翻译极限与误差机械零件的破坏，一般总是从表层开始的。

机械工程专业英语第二版康兰参考译文

机械工程专业英语第二版康兰参考译文康兰简介康兰（Kanglan）是一位著名的机械工程专业翻译家，他为机械工程学科领域的英文文献提供了许多优秀的译文。

他的翻译作品以准确、流畅、专业而闻名，并且广泛被机械工程专业人士所引用和使用。

本文将为大家介绍康兰参考译文的第二版，其中涵盖了机械工程专业的各个领域。

译文内容康兰参考译文第二版涵盖了机械工程专业的许多重要内容，包括但不限于机械设计、机械制造、机械控制、热力学、流体力学等领域。

以下是其中的一些示例：1. 机械设计在机械设计方面，康兰参考译文第二版提供了一些经典的翻译作品，如《机械设计基础》、《机械元件设计》等。

这些译文涵盖了机械设计的基本原理、方法和技术，包括机械设计的概念、设计流程、设计计算等。

2. 机械制造在机械制造方面，康兰参考译文第二版涵盖了广泛的内容，包括数控机床、机械加工工艺、机械加工精度等。

这些译文详细介绍了机械制造的各个方面，从机械加工的基本原理到机床的结构与控制，让读者对机械制造有一个全面的了解。

3. 机械控制在机械控制方面，康兰参考译文第二版为读者提供了丰富的内容。

这些译文涵盖了机械控制的基本概念、控制器的设计原理、控制算法等。

通过阅读这些参考译文，读者可以了解到机械控制的基本理论和应用技术。

4. 热力学在热力学方面，康兰参考译文第二版提供了一些经典的翻译作品，如《工程热力学》、《热能转换与利用》等。

这些译文介绍了热力学的基本概念、热力学循环、热力学定律等，对于研究热力学和热能转换有着重要的参考价值。

5. 流体力学在流体力学方面，康兰参考译文第二版提供了一些重要的翻译作品，如《流体力学基础》、《流体力学与传热学》等。

这些译文详细介绍了流体力学的基本原理、流体力学方程、流体力学模型等，对于学习和研究流体力学具有重要的参考价值。

总结康兰参考译文第二版是机械工程专业英语领域的重要参考书籍，它涵盖了机械工程专业各个领域的重要内容。

通过阅读这些译文，读者可以深入了解机械工程的基本理论、方法和技术，并且能够在实际工作中运用所学知识。

机械工程专业英语教程 (第5版)课件 (25)[9页]

《机械工程专业英语教程》
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Tolerance symbols: alphanumerical symbols giving the specifications of tolerances and fits; the basic size is a number, followed by the fundamental deviation letter and the IT number, which combined give the tolerance zone; uppercase letters indicate the fundamental deviations for holes, and lowercase letters indicate fundamental deviations
in roughness height measurements.
表面缺陷：不经常出现或者在很大区间内才会出现的表面瑕疵，其中包括裂纹、气孔、微细裂纹、划痕等。表面缺陷的影响在粗糙度的高度测量中通常会被忽略。
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Reamers 铰刀
International tolerance (IT) grade
A series of tolerances that vary with basic size to provide a
Lesson 28 Tolerances and Surface Roughness
• Terminology
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机械工程专业英语教程第2版Lesson(2)

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Text tour
The computer is bringing manufacturing into the Information Age. This new tool, long a familiar one in business and management operations, is moving into the factory, and its advent is changing manufacturing as certainly as the steam engine changed it more than 200 years ago.
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Tedious Tiresome by reason of length, slowness, or dullness, boring 单调乏味的：由于时间长、缓慢或呆滞而令人厌倦的 , 令人厌烦的。 Optimum 1. The point at which the condition, degree, or amount of 2. something is the most favorable 最佳效果：事物的条件、程度或数量的最合适点 2. Most favorable or advantageous, best 最好的：最适合或最有利的；最好的
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Computer integration may also lure new people into manufacturing. People are attracted because they want to work in a modern, technologically sophisticated environment. 计算机集成制造还会吸引新的人才进入制造业。人才被吸引过来的原因是他们希望到一个现代化的、技术先进的环

九江学院械工程专业英语期末复习

机械工程专业英语作业及期末复习作业一1.Most machining has very low set-up cost compared with forming, molding, and casting processes. However, machining is much more expensive for high volumes.译文：与成型加工、锻压和铸造工艺相比，大多数机械加工的生产准备成本都较低，然而如果是大批量生产，其成本要高得多。

2.Turning can occur on both external and internal surfaces to produce an axially-symmetrical contoured part.译文：车削可以加工外面和内表面以形成具有轴对称的成形工件。

3.Facing is the producing of a flat surface as the result of a tool’s being fed across the end of the rotating workpiece.译文：车端面可以加工出一个平面，它是当车刀沿回转工件的端面横向进给的结果。

4.Threading can be considered as turning since the path to be travelled by the cutting tool is helical.译文：车螺纹可以看作是车削，只是车刀所形成的加工轨迹是螺旋线。

5.many types of lathes are used for production turning . According to purposes and construction ,lathe-type machine tools can be classified as follows:译文：许多种类的车床都可以用于车削，根据它的目的和结构，车床可以分为以下几种类型。

外文翻译

附录Introduction to basic machiningMechanism of Surface Finish ProductionThere are basically five mechanisms which contribute to the production of a surface which have been machined. There are:(1) The basic geometry of the cutting process. In, for example, single point turning the tool will advance a constant distance axially per revolution of the work piece and the resultant surface will have on it, when viewed perpendicularly to the direction of tool feed motion, a series of cusps which will have a basic form which replicates the shape of the tool in cut.(2) The efficiency of the cutting operation. It has already been mentioned that cutting with unstable built-up-edges will produce a surface which contains hard built-up-edge fragments which will result in a degradation of the surface finish. It can also be demonstrated that cutting under adverse conditions such as apply when using large feeds small rake angles and low cutting speeds, besides producing conditions whichcontinuous shear occurring in the shear zone, tearing takes place, discontinuous chips of uneven thickness are produced, and the resultant surface is poor. This situation is particularly noticeable when machining very ductile materials such as copper and aluminum.(3) The stability of the machine tool. Under some combinations of cutting conditions: work piece size , method of clamping, and cutting tool rigidity relative to the machine tool structure, instability can be set up in the tool which causes it to vibrate. Under some conditions the vibration will built up and unless cutting is stopped considerable damage to both the cutting tool and work piece may occur. This phenomenon is known as chatter and in axial turning is characterized by long pitch helical bands on the work piece surface and short pitch undulations on the transient machined surface.(4) The effectiveness of removing sward. In discontinuous chip production machining, such as milling or turning of brittle materials, it is expected that the chip (sward) will leave the cutting zone either under gravity or with the assistance of a jet of cutting fluid and that they will not influence the cut surface in any way. However, when continuous chip production is evident, unless steps ate taken to control the swarf it is likely that it will impinge on the cut surface and mark it. Inevitably, this marking beside a looking unattractive, often results in a poorer surface finishing,(5) The effective clearance angle on the cutting tool. For certain geometries of minor cutting edge relief and clearance angles it is possible to cut on the major cutting edge and burnish on the minor cutting edge. This can produce a good surface finish but, of course, it is strictly a combination of metal cutting and metal forming and is not to be recommended as a practical cutting method. However, due to cutting tool wear, these conditions occasionally arise and lead to a marked change in the surface characteristics.Surface Finishing and Dimensional ControlProducts that have been completed to their proper shape and size frequently require some type of surface finishing to enable than to satisfactorily fulfill their function. In some cases, tit is necessary to improve the physical properties of the surface material for resistance to penetration or abrasion. In many manufacturing processes, the product surface is left with dirt, chips, grease, or other harmful material upon it. Assemblies that are made of different materials, or from the same materials processed in different manners, many require some special surface treatment to provide uniformity of appearance.Surface finishing many sometimes become an intermediate step processing. For instance, cleaning and polishing are usually essential before any kind of plating process. Some of the cleaning procedures are also used for improving surface smoothness on mating parts and for removing burrs and sharp corners, which might be harmful in later use. Another important need for surface finishing is for corrosion protection in a variety of environments. The type of protection procedure will depend largely upon the anticipated exposure, with due consideration to the material being protected and the economic factors involved.Satisfying the above objectives necessitates the use of main surface-finishing methods that involve chemical change of the surface mechanical work affecting surface properties, cleaning by a variety of methods, and the application of protective coatings, organic and metallic.In the early days of engineering, the mating of parts was achieved by machining one part as nearly as possible to the required size, machining the mating part nearly to size, and then completing its machining, continually offering the other part to it, until the desired relationship was obtained. If it was inconvenient to offer one par to the other part during machining, the final work was done at the bench by a fitter, who scraped the mating parts until the desired fit was obtained, the fitter therefore being a ‘fitter’ in the literal sense. It is obvious that the two parts wo uld have to remain together, and in the event of one having to be replaced, the fitting would have to be done all over again. I n these days, we expect to be able to purchase a replacement for a broken part, and for it to function correctly without the need for scraping and other fitting operations.When one part can be used ‘off the shelf’ to replace another of the same dimension and material specification, the parts are said to be interchangeable. A system of interchangeability usually lowers the production costs as there is no need for an expensive, ‘fiddling’ operation, and it benefits the customer in the event of the need to replace worn parts.Limits and TolerancesMachine parts are manufactured so they are interchangeable. In other words, each part of a machine or mechanism is made to a certain size and shape so it will fit into any other machine or mechanism of the same type. To make the part interchangeable, each individual part must be made to a size that will fit the mating part in the correct way. It is not only impossible, but also impractical to make many parts to an exact size. This is because machines are not perfect, and the tools becomeworn. A slight variation from the exact size is always allowed. The amount of this variation depends on the kind of part being manufactured. For example, a part might be made 6 in. long with a variation allowed of 0.003(three thousandths) in. above and below this size. Therefore, the part could be 5.997 to 6.003 in. and still be the correct size. These are known as the limits. The difference between upper and lower limits is called the tolerance.A tolerance is the total permissible variation in the size of a part.The basic size is that size from which limits of size are derived by the application of allowances and tolerances.Sometimes the limit is allowed in only one direction. This is known as unilateral tolerance.Unilateral tolerancing is a system of dimensioning where the tolerance (that is variation) is shown I only one direction from the nominal size. Unilateral tolerancing allow the changing of tolerance on a hole or shaft without seriously affecting the fit.When the tolerance is in both directions from the basic size, it is known as a bilateral tolerance (plus and minus).Bilateral tolerancing is a system of dimensioning where the tolerance (that is variation) is split and is shown on either side of the nominal size. Limit dimensioning is a system of dimensioning where only the maximum and minimum dimensions are shown. Thus, the tolerance is the difference between these two dimensions.Introduction of Machining of:Machining as a shape-producing method is the most universally used and the most important of all manufacturing processes. Machining is a shape-producing process in which a power-driven device causes material to be removed in chip form. Most machining is done with equipment that supports both the work piece and cutting tool although in some cases portable equipment is used with unsupported work piece.Low setup cost for small quantities. Machining has two applications in manufacturing. For casting, forging, and pressworking, each specific shape to be produced, even one part, nearly always has a high tooling cost. The shapes that may be produced by welding depend to a large degree on the shapes of raw material that are available. By making use of generally high cost equipment but without special tooling, it is possible, by machining, to start with nearly any form of raw material, so long as the exterior dimensions are great enough, and produce any desired shape from any material. Therefore, machining is usually the preferred method for producing one or a few parts, even when the design of the part would logically lead to casting, forging or pressworking if a high quantity were to be produced.Close accuracies, good finishes. The second application for machining is based on the high accuracies and surface finishes possible. Many of the parts machined in low quantities would be produced with lower but acceptable tolerances if produced I high quantities by some other process. On the other hand, many parts are given their general shapes by some high quantity deformation process and machined only on selected surfaces where high accuracies are needed. Internal threads, for example, are seldom produced by any means other than machining and small holes in pressworked parts may be machined following the pressworking operations.外文文献翻译机械加工基础简介表面粗糙度的技术在已经进行机械加工过的表面，有五种基本的影响其表面粗糙度的技术。

机械工程英语第2版叶邦彦Unit 14

Unit 14Limits and Tolerances1.Dimensioning2.Dimension and Tolerance3.Tolerances Limits and Fits4.Type of Limits and Fits1.DimensioningTolerances must be placedon the dimensions of a drawing to limit the permissiblevariations in size because it isimpossible to manufacture apart exactly to a givendimension. Although smalltolerances give higher qualitywork and a better operatingmechanism, the cost ofmanufacture increases rapidlyas the tolerances are reduce,as indicated by the typical curve of Fig.1.Fig.1 Relationship between size of tolerance and cost of production2. Dimension and ToleranceTolerance is the amount of variation permitted in the part or the total variation allowed in a given dimension.Tolerances may be either unilateral[单边的] or bilateral [双边的].Unilateral tolerance means that any variation is made in only one direction from the nominal or basic dimension.0.0030.0001.500+-Bilateral tolerance meansthat the tolerance would vary both over and under the nominal dimension.1.5000.003±3. Tolerances Limits and FitsA tolerance is the difference in a dimension in order toallow for unavoidable imperfections in workmanship. Thetolerance range will depend on :●the accuracy of the manufacturing organisation [组织]●the machining process●the magnitude of the dimensionLimits are the extreme dimensions of the tolerance zone.For example, nominal dimension30 mm tolerance 30.02530.000++limits 30.02530.000Fits depend on the relationship between the tolerance zones of two mating parts, and may be broadly classified into a clearance fit with positive allowance, a transition fit where the allowance may be either positive or negative (clearance or interference), an interference fit where the allowance is always negative.4. Type of Limits and FitsThere are three classes of fits:1)clearance fits2)transition fits3)interference fitsThe tolerance is a function of the basic size and is designated by a number symbol, called the grade —thus the tolerance grade.Twenty standard grades of tolerances are provide, called IT 01, IT 0, IT 1-18, providing numerical values for each nominal diameter, in arbitrary steps up to 500 mm(for example 0-3, 3-6, 6-10, …, 400-500 mm).Clearance FitA clearance fit is one having limits of size defined suchthat a clearance always results when mating parts areassembled.Transition FitA transition fit is one having limits of size so prescribed [规定]that either a clearance or an interference mat result when mating parts as assembled.Interference FitAn interference fit is one having limits of size soprescribed that an interference always results when matingparts are assembled.。

机械工程专业英语PPT课件

Bearing
A device that supports, guides, and reduces the friction of
motion between fixed and moving machine parts. 轴承：在机器的固定和运动部件之间起支撑、引导和减少运动摩擦的装置。
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Lesson 1 Basic Concept in Mechanics
Terminology 术语,专有名词
[,tə:mi'nɔlədʒi]
Text tour
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Terminology
Gear 齿轮, 传动装置
1.A toothed machine part, that meshes with another toothed part to transmit motion or to change speed or direction. 齿轮：有齿的机器零件，与另一个有齿零件相啮合，从而传递运动或者改变运动的方向或速度。
唐一平主编：《先进制造技术》北京：机械工业出版社，2004；
王慧莉，贾卫国编《国际学术交流英语》大连：大连理工大学出版社，2005
主要教学内容
Lesson 1 Basic Concept in Mechanics Lesson 2 Forces and Their Effects Lesson 3 Overview of Engineering Mechanics Lesson 4 Shafts and Couplings Lesson 5 Shafts and Associated Parts Lesson 6 Belts, Clutches, Brakes, and Chains Lesson 7 Fasteners and Springs Lesson 14 Physical Properties of Materials Lesson 29 Tolerances and Surface Roughness Lesson 35 Coordinate Measuring Machine Lesson 36 Lathes

2021年同济大学机械工程专业英语翻译

同济大学机械工程专业英语翻译目录 UNIT 1 ADVANCED ENGINEERING MATERIALS - 1 - UNIT 2 HEAT TREATMENT OF METALS - 6 - UNIT 3 CASTING PROCESSES - 15 - UNIT 4 FORGING PROCESSES - 21 - UNIT 5 POWDER METALLURGY - 26 - UNIT 6 INJECTION MOLDING - 32 - UNIT 7 METAL CUTTING - 38 - UNIT 8 GRINDING - 45 - UNIT 9 LAPPING POLISHING - 49 - UNIT 10 SURFACE ENGINEERING - 51 - UNIT 12 DRILLING AND MILLING - 63 - UNIT 13 JIGS AND FIXTURES - 68 - UNIT 14 LIMIT AND TOLERANCES - 72 - 特种 ___工艺（Ⅰ、Ⅱ） - 77 - UNIT 1 Advan ___d Engineering Materials Types of Materials材料的类型 Materials ___y be grouped inseveral ways. Scientists often classify ___terials by their state: solid, liquid, or gas. They also separate them into organic (on ___ living) and inorganic (never living)___terials.材料可以按多种方法分类。

科学家常根据状态将材料分为：固体、液体或气体。

他们也把材料分为有机材料(曾经有生命的)和无机材料(从未有生命的)。