毕业设计--圆振动筛设计的外文翻译

合集下载

轴类毕业设计英文翻译、外文文献翻译

ShaftSolid shafts. As a machine component a shaft is commonly a cylindrical bar that supports and rotates with devices for receiving and delivering rotary motion and torque .The crankshaft of a reciprocating engine receive its rotary motion from each of the cranks, via the pistons and connecting roads (the slider-crank mechanisms), and delivers it by means of couplings, gears, chains or belts to the transmission, camshaft, pumps, and other devices. The camshafts, driven by a gear or chain from the crankshaft, has only one receiver or input, but each cam on the shaft delivers rotary motion to the valve-actuating mechanisms.An axle is usually defined as a stationary cylindrical member on which wheels and pulleys can rotate, but the rotating shafts that drive the rear wheels of an automobile are also called axles, no doubt a carryover from horse-and-buggy days. It is common practice to speak short shafts on machines as spindles, especially tool-carrying or work-carrying shafts on machine tools.In the days when all machines in a shop were driven by one large electric motor or prime mover, it was necessary to have long line shafts running length of the shop and supplying power, by belt, to shorter couter shafts, jack shafts, or head shafts. These lineshafts were assembled form separate lengths of shafting clampled together by rigid couplings. Although it is usually more convenient to drive each machine with a separate electric motor, and the present-day trend is in this direction, there are still some oil engine receives its rotary motion from each of the cranks, via the pistons and connecting roads (the slider-crank mechanisms) , and delivers it by means of couplings, gears, chains or belts to the transmission, camshaft, pumps, and other devices. The camshafts, driven by a gear or chain from the crankshaft, has only one receiver or input, but each cam on the shaft delivers rotary motion to the valve-actuating mechanisms.An axle is usually defined as a stationary cylindrical member on which wheels and pulleys can rotate, but the rotating shafts that drive the rear wheels of an automobile are also called axles, no doubt a carryover from horse-and-buggy days. It is common practice to speak short shafts on machines as spindles, especially tool-carrying or work-carrying shafts on machine tools.In the days when all machines in a shop were driven by one large electric motor or prime mover, it was necessary to have long line shafts running length of the shop and supplying power, by belt, to shorter coutershafts, jackshafts, or headshafts. These line shafts were assembled form separatelengths of shafting clampled together by rigid couplings. Although it is usually more convenient to drive each machine with a separate electric motor, and the present-day trend is in this direction, there are still some situation in which a group drive is more economical.A single-throw crankshaft that could be used in a single-cylinder reciprocating engine or pump is shown in Figure 21. The journals A andB rotate in the main bearings,C is the crankpin that fits in a bearing on the end of the connecting rod and moves on a circle of radius R about the main bearings, whileD andE are the cheeks or webs.The throw R is one half the stroks of the piston, which is connected, by the wrist pin, to the other end of the connecting rod and guided so as to move on a straight path passing throw the axis XX. On a multiple-cylinder engine the crankshaft has multiple throws---eight for a straight eight and for a V-8---arranged in a suitable angular relationship.Stress and strains. In operation, shafts are subjected to a shearing stress, whose magnitude depends on the torque and the dimensions of the cross section. This stress is a measure of resistance that the shaft material offers to the applied torque. All shafts that transmit a torque are subjected to torsional shearing stresses.In addition to the shearing stresses, twisted shafts are also subjected to shearing distortions. The distorted state is usually defined by the angle of twist per unit length; i.e., the retation of one cross section of a shaft relative to another cross section at a unit distance from it.Shafts that carry gears and pulleys are bent as well as twisted, and the magniude of the bending stresses, which are tensile on the convex side of the bend and compressive on the concave side, will depend on the load, the distance between the bearings of the shaft cross section.The combination of bending and twisting produces a state of stress in the shaft that is more complex than the state of pure shears produced by torsion alone or the state of tension-compression produced by bending alone.To the designer of shaft it is important to know if the shaft is likely to fail because of an excessive normal stress. If a piece of chalk is twisted, it will invariably rupture on a plane at about 45 degrees to the axis. This is because the maximum tensile stresses act on this plane, and chalk is weak in tension. Steel shafting is usually designed so that the maximum shearing stress produced by bending and torsion is less than a specified maximum.Shafts with circular cross sections are easier to produce in the steel mill, easier to machine, andeasier to support in bearings than shafts with other cross section; there is seldom any need for using noncircular shapes. In addition, the strength and stiffness, both in bending and torsion, are more easily calculated for circular shafts. Lastly, for a given amount of materials the circular shafts has the smallest maximum shearing stress for a given torque, and the highest torsional rigidity.The shearing in a circular shaft is highest at the surface and drops off to zero at the axis. This means that most of the torque is carried by the material on and near the surface.Critical speeds. In the same way that a violin string vibrates when stroked with a bow, a cylindrical shaft suspended between two bearings has a natural frequency of lateral vibration. If the speed of revolution of the shaft coincides with the natural frequency, the shaft experience a whirling critical speed and become noisy. These speeds are more likely to occur with long, flexible shafts than with short, stiff ones. The natural frequency of a shaft can be raised by increasing its stiffness.If a slender rod is fixed to the ceiling ta one end and supports a heavy disk at the other end, the disk will oscillate back and forth around the rod axis like a torsion pendulum if given an initial twist and let go. The frequency of the oscillations will depend on the torsional stiffness of the rod and the weight of the disk; the stiffer the rod and the lighter the disk the higher the frequency. Similar torsional oscillations can occur in the crankshafts of reciprocating engines, particularly those with many crank throws and a heavy flywheel. Each crank throw and part of the associated connecting rod acts like a small flywheel, and for the crankshaft as a whole, there are a number of ways or modes in which there small flywheels can oscillate back and forth around the shaft axis in opposition to one another and to the main flywheel. For each of these modes there corresponds a natural frequency of oscillation.When the engine is operating the torques delivered to the crankshaft by the connecting rods fluctuate, and if the crankshaft speed is such that these fluctuating impulses are delivered at a speed corresponding to one of the natural torsional frequencies of the shaft, torsional oscillations will be superimposed on the rotary motion of the shafts. Such speed are known as torsional critical speeds, and they can cause shaft failures. A number of devices to control the oscillations of crankshafts have been invented.Flexible shafts. A flexible shaft consists of a number of superimposed tightly wound right-and left-hand layers of helically wound wires wrapped about a single center wire or mandrel. The shaft is connected to source of power and the driven member by special fittings attached to the end of theshaft. Flexible easings of metallic or nonmetallic materials, which guide and protect the shaft and retain the lubricant, are also available. Compared with solid shafts, flexible shafts can be bent to much smaller radii without being overstressed.For transmitting power around corners and for considerable distances flexible shafts are usually cheaper and more convenient than belts, chains, or gears. Most speedometers on automobiles are driven by flexible shafts running from the transmission to the dashboard. When a valve, a switch, or other control devices is in a hard-to-reach location, it can be operated by a flexible shaft from a more convenient position. For portable tools such as sanders, grinders, and drilling machines, flexible shafts are practically indispensable.KEY, SPLINES AND PINSKeys, splines, and pins. When power is being transmitted from a machine member such as a coupling, a gear, a flywheel, or a pulley to the shaft on which it is mounted, means must be provided for preventing relative motion between the shaft and the member. On helical and bevel gears, relative movement along the shaft caused by the thrust(axial) loads is prevented by a step in the shaft or by having the gear contact the bearing directly or through a tubular spacer. When axial loads are incidental and of small magnitude, the members are kept from sliding along the shaft by means of a set screw. The primary purpose of keys, splines, and pins is to prevent relative rotary movement.A commonly used type of key has a square cross section and is sunk half in the shaft and half in the hub of the other member. If the key is made of steel(which is commonly the case)of the same strength as the shaft and has a width and depth equal to one fourth of the shaft diameter(this proportion is closely approximated in practice) then it will have the same torque capacity as the solid shaft if its length is 1.57 times that of the shaft diameter. Another common type of key has a rectangular cross section with a depth to width ratio of 0.75. Both of these keys may either be straight or tapered in depth. The straight keys fit snugly on the sides of the key ways only, the tapered keys on all sides. Gib-head keys are tapered keys with a projection on one end to facilitate removal.Woodruff keys are widely used on machine tools and motor vehicles. The key is a segment of adisk and fits in a keyway in the shaft that is with a special milling cutter. Though the extra depth of these keys weakens the shaft considerably, it prevents any tendency of the key to rotate or move axially. Woodruff keys are particularly suitable for tapering shaft ends.Because they weaken the shafts less, keys with straight or tapered circular cross sections are sometimes used in place of square and rectangular keys, but the keyways, half in the shaft and half in the shaft and half in the hub, must be cut with a drill after assembly,and interchangeability of parts is practically impossible. When a large gear blank is made by shrinking a high-strength rim on a cheaper cast center, circular keys, snugly fitted, are frequently used to ensure a permanent connection.Splines are permanent keys integral with the shaft, fitting in keyways cut in the hub. The dimensions of splined fittings are standardized for both permanent (press) fits and sliding fits. The teeth have either straight or involute profiles;the latter are stronger, more easily measured, and have a self-centring action when twisted.Tapered circular pins can be used to restrain shaft-mounted members from both axial and rotary movement. The pin fits snugly in a reamed tapered hole that is perpendicular to the shaft surface. A number of straight pins that grip by deforming elastically or plastically when driven into straight holes are commercially available.All the keys and pins that have been described are standard driving devices. In some cases they inadequate, and unorthodox means must be employed. For driving small gear in which there is no room between the bore and the roots of the teeth for a longitudinal keyway, a transverse radial slot on the end of the gear can be made to fit a radial protuberance on the shaft. For transmitting moderate loads, a cheaper and effective connection can be made by forming a series of longitudinal serrations on the shaft with a knurling tool and pressing the shaft into the hole in the driven member, it will cut grooves in the hole and provide, in effect, a press-fitted splined connection. Press and shrink fits are also used, and they can provide surprisingly firm connections, but the dimensions of the connected member must be closely controlled.轴实心轴轴作为机械零件通常是一根圆柱形杆，用来支撑部件并随部件一起转动以接受和传递转动和扭矩。

YAH2460型圆振动筛设计

（2-5）（2-6）
由运动特征，来研究筛子上物料的运动学。物料在筛面上可能出现三种运动状态：正向滑动、反向滑动和跳动。
2.2 正向滑动
当物料颗粒与筛面一起运动时，其位移、速度和加速度与筛面的相等。筛面上质量为 m 的物料颗粒动力平衡条件：对质量为 m 的颗粒受力分析（如图 2-1）： 1、物料颗粒重力：
4
南昌航空大学科技学院学士论文
向大型化方向发展，但最大到 55m2，已够用了；增大筛面倾角，提高筛分效率；发展细粒筛分设备，筛孔尺寸小到 0.1 ～ 0.3 毫米；旋流筛使用逐渐增多；共振筛发展停滞。 2. 国内技术发展趋势积极开展筛分技术研究，提高原煤干式深度筛分技术，降低分级下限和增加煤炭品种，着重解决粒度细、水分高和黏度大的难筛物料的分级技术；为满足大露天矿选用，研制重型分级筛，适用于 500 毫米以下物料筛分；为提高筛板的寿命和效果，着重发展焊接筛网，非金属筛面；共振筛有被淘汰之势，应大力发展块偏心圆振动筛和直线振动筛。
南昌航空大学科技学院学士论文
1 绪论
1.1 前言
振动筛是工矿企业普遍应用的筛分机械，用作物料的筛分、分级、洗涤、脱介、脱水之用。筛分设备技术水平的高低和质量的优劣，关系到工艺效果的好坏、生产效率的高低和能源节省的程度，从而直接影响企业的经济效益。而振动筛以它结构简单、处理能力大、工作可靠等优点在所有筛分设备中占有绝对优势，其占有量约为 95％。最近几年，各国对振动筛分技术的研究很重视，如强化振动参数，设备大型化，筛机零部件的三化，自同步技术的推广应用，新筛机的出现等都是围绕着振动筛发展起来的。下面就振动筛发展概况、品种规格、结构强度作一下阐述。
1.2 背景
1.2.1 国内外研究现状 1. 国外研究现状国外从 16 世纪开始筛分机械的研究与生产，在 18 世纪欧洲工业革命时期，筛分机械得到迅速发展，到本世纪，筛分机械发展到一个较高水平。德国申克公司可提供 260 多种筛分设备，STK 公司生产的筛分设备系列品种较全，技术水平较高，KHD 公司生产 200 多种筛分设备，通用化程度较高，KUP 公司和海因勒曼公司都研制了双倾角的筛分设备。美国 RNO 公司新研制 DF11 型双频率筛，采用了不同速度的激振器。DRK 公司研制成三路分配器给料，一台高速电机驱动。日本东海株式会社和 RXR 公司等合作研制了垂直料流筛，把旋转运动和旋回运动结合起来，对细料一次分级特别有效。英国为解决从湿原煤中筛出细粒末煤，研制成功旋流概率筛。前苏联研制了一种多用途兼有共振筛和直线振动筛优点的自同步直线振动筛。 2. 国内研究现状由于工业发展缓慢，基础比较薄弱，理论研究和技术水平落后，我国筛分机械的发展是本世纪近 50 年的事情，大体上可分为三个阶段。 (1) 仿制阶段：这期间，仿制了前苏联的ГУП 系列圆振动筛、 BKT-11、 BKT-OMZ 型摇动筛；波兰的 WK-15 圆

一种新型振动筛(圆振动筛)的毕业设计讲解

**********大学毕业论文（设计）题目：一种新型振动筛的设计姓名：*********学院：机电工程学院专业：机械设计制造及其制动化班级：************学号：**************指导教师：*****************年**** 月*****日毕业论文（设计）诚信声明本人声明：所呈交的毕业论文（设计）是在导师指导下进行的研究工作及取得的研究成果，论文中引用他人的文献、数据、图表、资料均已作明确标注，论文中的结论和成果为本人独立完成，真实可靠，不包含他人成果及已获得********大学或其他教育机构的学位或证书使用过的材料。

与我一同工作的同志对本研究所做的任何贡献均已在论文中作了明确的说明并表示了谢意。

论文（设计）作者签名：日期：年月日毕业论文（设计）版权使用授权书本毕业论文（设计）作者同意学校保留并向国家有关部门或机构送交论文（设计）的复印件和电子版，允许论文（设计）被查阅和借阅。

本人授权********大学可以将本毕业论文（设计）全部或部分内容编入有关数据库进行检索，可以采用影印、缩印或扫描等复制手段保存和汇编本毕业论文（设计）。

本人离校后发表或使用该毕业论文（设计）或与该论文（设计）直接相关的学术论文或成果时，单位署名为*********大学。

论文（设计）作者签名：日期：年月日指导教师签名：日期：年月日目录摘要 (I)Abstract (II)1绪论 (1)1.1前言 (1)1.2振动筛的分类 (1)1.3国内外筛分机械的发展现状 (2)1.4振动筛的发展趋势 (3)2振动筛筛面物料运动理论 (4)2.1筛上物料的运动分析 (4)2.2正向滑动 (5)2.3反向滑动 (6)2.4跳动条件的确定 (7)3振动筛的工作原理及结构组成 (9)3.1圆振动筛的工作原理 (9)3.2 YA圆振动筛的基本结构 (9)4振动筛的参数计算选择 (12)4.1确定振动筛的运动学参数 (12)4.2振动筛工艺参数的确定 (14)4.3动力学参数 (16)4.4电动机的选择 (17)5 主要零件的设计与计算 (18)5.1轴承的选择与计算 (18)5.2皮带的设计 (19)5.3键的设计 (23)5.4轴的设计 (24)5.5支承弹簧的设计验算 (26)6 振动筛的安装维护 (30)6.1振动筛的安装及调试 (30)6.2振动筛操作的要点 (31)6.3振动筛维护与检修 (31)7总结 (33)参考文献 (34)致谢 (35)一种新型振动筛的设计摘要目前传统的筛分机械生产率低下，难以筛分出一些细粒状物，并且振动筛强度和刚度较低，使用寿命短。

毕业设计(论文)振动筛设计(全套图纸)

摘要振动筛的研究不断地向着标准化、系列化、通用化发展，并引入现代化设计手段，采用新材料、新技术、新工艺，其目的在于不断扩大筛机应用领域，满足国民经济建设发展的需要，并担当对外出口的任务。

本文所设计的振动筛的筛分物料为球磨机产品。

该产品的大小不是很平均，为了做出更符合要求的物料就需要用振动筛来将球磨机产品进一步细分，将不符合要求的物料重新用球磨机磨小。

经过这样的反复处理最终将物料全部做成符合要求的产品。

本课题的振动筛为自同步双振动电机驱动的，其特点是结构简单、安装方便、成本低、容易操作及维护等。

其筛箱为板梁铆焊组合结构，由主副侧板、管梁、入料挡板、出料板、筛板等组成，侧板选用低合金压力容器钢板，强度高、可焊性好，周边折弯，并在振动方向及沿纵向连接多根角钢，使侧板刚度大大增强，有利于强度的提高和噪音的降低。

管梁由法兰盘、无缝钢管、加强槽钢等组成，重量轻、强度大，便于制造安装，具有互换性。

加强槽钢上有T形孔，使用T形螺栓，便于筛板的安装维护，消除U形螺栓对管梁的磨损。

工作原理：两台振动电机的型号相同，可以产生一种组合的直线振动。

这种振动可以使输送槽体中的物料运动，并与筛面发生碰撞，使小于筛孔的物料透过，从而实现物料的几何分级，实现筛分。

总体方案为：采用普通筛分法，振动形式为共振，运动轨迹为直线运动，激振方式为惯性式，隔振方式为一级隔振，隔振弹簧为金属螺旋式隔振弹簧。

关键词：振动筛; 筛箱; 振动电机全套CAD图纸，联系695132052AbstractThe shaker research unceasingly to the standardization, the seriation, the universalized development, and the introduction modernization design method, uses the new material, the new technology, the new craft, its goal lies in unceasingly expands the sieve machine application domain, satisfies national economy construction the need to develop, and takes on the foreign exportation the duty.Finally completely makes after such repeatedly processing the materi all tallies the request product. This topic shaker for self-synchronizing pair vibration motor-driven, Its characteristic is the structure simple, the installs convenient, the cost low, is easy to operate and the maintenance and so on. It sieves the box is board crossbeam riveting hitch welds built-up section, By host vice- side bar, Hollow beam, Enters the material back plate, Leaves material board, Sieves board and so on composition, The side bar selects the low-alloy pressure vessel steel plate, The intensity is high, The weldability is good, Peripheral knee bend, And in the vibration direction and along longitudinal connects themulti- roots angle steel, Causes the side bar rigidity big enhancement, Is advantageous to the intensity enhancement and noise reducing. Hollow beam by flange plate, Seamless steel pipe, Strengthens composition and so on channel steel, The weight light, the intensity is big, is advantageous for themanufacture installment, Has the interchangeability. Strengthens in the channel steel to have the T shape hole, Uses the T shape bolt, Is advantageous for screen board installs the maintenance, Eliminates the U shape bolt to the hollow beam attrition. Principle of work: Two vibrate the electrical machinery the model to be same, May have one kind of combination straight-line oscillation. This kind of vibration may cause in the transportation trough body thematerial movement, And has the collision with the screening surface, And has the collision with the screening surface, Thus realization material geometry graduation, Realization screening. The overall plan is: Uses the ordinary screening law, The vibration form for resonates, The path is the translation, Stirs up the strength vibration the way is the inertia type, The vibration isolation way is level of vibration isolations, The vibration isolation spring is the metal screw type vibrationisolation spring。

振动筛外文翻译11

振动筛外文翻译Line Vibrating Screen overviewThe use of linear vibrating screen Vibrating motor as vibration source excitation, so that materials in the sieve to be toss-line, at the same time for straight forward exercise, material from the feeder evenly into the screening machine feed through the mesh have a number of multi-storey sieve specifications on materials, sieve under物, separately from their respective export discharged. With low energy consumption, high output, simple structure, easy maintenance, full-closed structure, no dust, automatic nesting, more suitable for pipelined operation .Linear Vibrating Screen Working Principle:Linear Vibrating Screen Vibrating motor-driven double, when the two make Vibrating motor synchronization, anti-缶rotation, the eccentric block excitation forcegenerated by the electrical axis in parallel to the direction of offset each other, perpendicular to the motor shaft at the direction of stack for the one together, so the exercise machine for straight line trajectory. Its two-motor shaft relative screen surface has a dip in the excitation force and material self-gravity force role, the materials in the sieve surface by leaps and bounds toss straight forward for the sport, so as to achieve on the materials selection and classification purposes. Can be used to achieve automated assembly line in operation.With low energy consumption, high efficiency, simple structure, easy maintenance, full-closed structure without dust溢散characteristics. Maximum 325 mesh screen mesh can be screening outof seven kinds of different particle size materials.The use of linear vibrating screenOf powder, granular materials selection and classification, widely used in plastics, abrasives, chemicals, medicine, building materials, food, carbon, fertilizer and other industries.Linear Vibrating Screen (straight-line screen) is a new type of highly efficient screening equipment, widely used in mining, coal, metallurgy, building materials, refractories, light industry, chemical industry. Linear Vibrating Screen (linear sieve) stable and reliable, consume less, low noise, long life, vibration-type steady, screening and high efficiency.Linear Vibrating Screen technical parametersSZF-520-type 1S-Q235A or SUS304 2000 × 500 × 1200 1 layer (1S) 2 layer (2S)3 layers (3S)4 layers (4S)SZF-525-type 1S-Q235A or SUS304 2500 × 500 × 1200 1 layer (1S) 2 layer (2S)3 layers (3S)4 layers (4S)SZF-825-type 1S-Q235A or SUS304 2500 × 800 × 1200 1 layer (1S) 2 layer (2S)3 layers (3S)4 layers (4S)SZF-820-type 1S-Q235A or SUS304 2000 × 800 × 1200 1 layer (1S) 2 layer (2S)3 layers (3S)4 layers (4S)SZF-1025-type 1S-Q235A or SUS304 2500 × 1000 × 1500 1 layer (1S) 2 layer(2S) 3 layers (3S) 4 layers (4S)SZF-1225-type 1S-Q235A or SUS304 2500 × 1200 × 1500 1 layer (1S) 2 layer(2S) 3 layers (3S) 4 layers (4S)SZF-1235-type 1S-Q235A or SUS304 3500 × 1200 × 1600 1 layer (1S) 2 layer(2S) 3 layers (3S) 4 layers (4S)SZF-1536-type 1S-Q235A or SUS304 1500 × 3600 × 1200 1 layer (1S) 2 layer(2S) 3 layers (3S) 4 layers (4S)Information on the use of instructionsFeatures ? ?1) unique mesh design, convenient and rapid replacement of screen (only 3-5 minutes), in addition to such designPermit the use of mesh (nylon, special long, PP Net).2) screen design; compact and easy to assemble, one person can operate machine. 3) and other related brands comparison, a larger filter area and high efficiency of processing power.4) the parent fully support Net Net fine, so fine-Net can be an exclusive right of a longer life expectancy, and reduce the use of fine-Net supplies, deposition time of the production process can reduce a lot of cost.Linear vibrating screen role and the principle ofThe basic principles of the Department of Motor Borrow shaftinstalled on the bottom of a heavy hammer (Heng uneven weight), the rotation of motor sport will be transformed into horizontal, vertical, inclined three-sport, and then communicated to the sports screen surface. If the change in weights up and down the Department of the phase angleof the road can change the direction of raw materials.Electrical Usage:This series of motors to meet the following conditions when continuous output rated excitation.1, vibration acceleration: no more than 7g (g: acceleration due to gravity) 2, ambient temperature: not more than 40 ?3, above sea level: not exceed 1000m4, power supply frequency: 50Hz5, voltage: 380V6, the temperature rise: less than 80K (resistance method)Linear vibrating screen, as well as the various parts of thestructure function .This machine mainly by the screen box, screen frames, screen,vibration motor, electric pedestal, damping spring, frame and so on.1, sieve boxes: from a few different kinds of thickness of steel plate welded together with a certain degree of strength and stiffness, are the main machine components. 2, screen box: deformation from pine or smaller made of wood, mainly used tomaintain the mesh formation, the normal screen.3, screen: there is low-carbon steel, brass, bronze, several species such as stainless steel wire mesh.4, Vibrating motor (using the repair method with the use ofVibrating motor detailed instructions).5, the electrical pedestal: Vibrating motor installation, use pre-connect screw must be tightened, especially the new machine three days before trial must be repeated fastening to prevent loosening of the accident.6, damping spring: to prevent vibration to the ground, while supporting the full weight of the sieve case, the installation, the spring must be vertical with the ground. 7, frame: from the four pillars and two channel components to support the screen box, the installation must be vertical with the ground pillars, two pillars of the following should be mutually parallel channel.Linear vibrating screen to install the pre-preparation1, check whether the motor signs in line with the requirements.2, using 500-volt megohm insulation resistance measurement table, and its value to deal with stator windings drying treatment, drying temperature should not exceed 120 ?.3, inspection of all electrical fasteners, to guard against loosening. 4, check whether the damage to the electrical surface deformation.5, check whether the rotating flexible, if abnormal, should be excluded. 6, check power supply, whether the lack of phase, and no-load operation of 5 minutes.Installation and adjustment1, the electrical be fasteners at the installation level, the installation must be smooth and flat.2, the level of motor can be installed.3, the electrical lead-core rubber cable using four YZ-500V, thenthe power cable isnot allowed when there is urgency pinout folding and reliable fixed-body vibration. 4, the electrical grounding should be reliable, there is within the electrical grounding device, lead client has signs at the end of the foot can also make use of a solid grounding bolt.5, the adjustment of excitation force.Linear vibrating screen use and repair1, the machine should be installed in the electrical protection device. 2, the machine is running early, check every day for at least one anchor bolts to prevent loosening.3, when the motor rotation direction inconsistent with the requirements, you can adjust the power phase sequence.4, the electrical should guarantee good lubrication, each running about two weeks to add lithium-based grease (ZL-3) once, come on, through the oil cups add appropriate amount of lithium-based grease. When the use of sealed bearings, the motor is not installed on the oil cup.5, the machine is running a total of 1500 hours, they should check the bearings, if serious injury should be immediately replaced.6, the local parking again after a longer period of time when used in insulation resistance should be measured for the 500-volt megohm table measurements, should be larger than 0.5 megohm.Linear Vibrating Screen routine maintenance1, start before:(1) Inspection of rough and fine Net Net availability of breakage(2) to check whether the removal of transport support. 2, start at:(1) watch for abnormal noise(2) whether the current stability(3) whether the vibration3, use: that is, each time after use clean up.Regular maintenanceNet regular inspection of rough, small networks and the availability of spring fatigueand damage, whether the various parts of the airframe vibration caused damage, needto add lubricants lubrication parts must come on.直线振动筛概述直线振动筛利用振动电机激振作为振动源，使物料在筛网上被抛起，同时向前作直线运动，物料从给料机均匀地进入筛分机的进料口，通过多层筛网产生数种规格的筛上物、筛下物、分别从各自的出口排出。

机械工程自动化毕业设计-圆振动筛偏心块装置(激振装置)设计

机械工程自动化毕业设计-圆振动筛偏心块装置（激振装置）设计本科毕业设计题目：圆振动筛偏心块装置（激振装置）设计学院: 机械自动化学院专业: 机械工程及自动化学号:学生姓名:指导教师:日期: 二〇一三年六月摘要目前在我国各种矿山机械设备中，振动筛是问题较多、维修量较大的设备之一。

这些问题突出表现在筛箱断梁、裂帮,稀油润滑的振动器漏油、齿轮打齿、轴承温升过高、噪声大等问题，同时伴有传动带跳带断带等故障。

这类问题直接影响了振动筛的使用寿命，严重影响了生产效率。

本设计对振动筛进行了方案论述，包括振动筛的分类与特点，确定了设计方案；进行了物料的运动分析、振动筛的动力学分析，以及动力学参数的计算，合理设计了振动筛的结构尺寸；进行了激振器的偏心块设计与计算（包括原始的设计参数）；进行了轴承的选择和计算，与电动机设计与校核；进行了主要零部件的设计与计算，如皮带的设计计算与校核，弹簧的设计计算，轴的强度有限元分析，然后进行了设备维修、安装、润滑及密封的设计。

关键词：圆振动筛；激振器；有限元法abstractAt present,among the varied mine machineries the shaker is one of the devices which need frequent maintenance and have their own problems. For the shaker, such problems consist of breakages for beam, straining box, and sieve plate; oil spill out when the vibration exciter used oil lubrication; meantime, the bearing may break in the high work temperature. What’s more, the vibration exciter also produces big noise. All these issues directly influence the life of the shaker, and they also seriously affect the production rate.The framework about designing shaker has been introduced, including the classification and features, and design program of the shaker; After analyzing on the shaker’s dynamics of the shaker, the structure of vibrating screen size has been designed; conducting the research of the eccentric block of the exciter, afterward, design and calculate for the original parameters concerned with; designing and verification for the main components, such as motor, belts, spring, the axis, bearings. Then the maintenance of equipment, installation, lubrication and the design for sealing have been studied in the latter part of this project. What’s important in this design, Finite Element Method (FEM) has been used to compute the strength of an critical axle on the round exciter.Key words:Round Shaker; Vibrator; FEM目录1 绪论 (1)1.1 前言 (1)1.2 课题研究背景 (1)2 设计任务 (2)2.3 设计任务 (2)3 单轴圆运动惯性振动筛的构造与特点 (3)3.1 简单振动筛 (3)3.2 自定中心振动筛 (3)3.3 其他形式的圆振筛 (3)3.4 单轴圆振筛激振器及其存在问题 (4)3.4.1 激振器 (4)3.4.2 激振器中的偏心块 (4)4 圆振筛物料运动的基本原理 (6)4.1 圆振筛筛面物料受力分析 (6)4.2 出现正向滑行的条件和正向滑行指数 (7)4.3 出现反向滑行的条件及反向滑行指数 (9)4.4 出现抛掷运动的条件及抛掷指数 (10)5 振动筛的参数选取计算与动力分析 (12)5.1 振动筛运动学参数的选取与计算 (12)5.1.1 抛掷指数D (12)5.1.2 振动强度K (12)5.1.3 筛面倾角α (13)5.1.4 筛箱的振幅A (13)5.1.5 振动次数n (13)5.1.6 实际振动强度K (13)s5.1.7 物料的理论平均速度和实际平均速度 (13)5.2 振动筛工艺参数的选取与计算 (15)5.2.1 筛面的长度和宽度 (15)5.2.2 筛机的生产率和筛分效率 (15)5.3 振动筛的动力学分析以及动力学参数的选取与计算 (16)6 激振器主要零件的设计与计算 (24)6.1 激振器偏心块的设计及校核 (24)6.2 轴承选取以及校核 (27)6.3 电工功率的计算以及电动机的选取： (29)6.4 键的选取与校核 (30)6.5 带的设计 (31)6.5.1 选取皮带的型号 (31)6.5.2 传动比 (31)6.5.3 带轮的基准直径 (31)6.5.4 带速 (32)6.5.5 确定中心距和带的基准长度.. 326.6 轴的设计与校核 (34)6.6.1 轴的设计形状 (34)6.6.2 轴的有限元分析（校核） (35)7 振动筛的安装维护及润滑 (38)7.1 振动筛的安装及调试 (38)7.1.1 安装前的准备 (38)7.1.2 安装 (38)7.1.3 试运转 (38)7.2 操作要点 (39)7.3 维护与检修 (39)7.3.1 维护 (39)7.3.2 常见故障处理 (40)7.4 振动筛的轴承润滑的改进 (40)结束语 (42)参考文献 (43)致谢 (44)附录 (45)1 绪论1.1前言从井下或露天采矿开采出来的或经过破碎的物料，是以各种大小不同的颗粒混合在一起的。

毕业设计---振动筛外文翻译

第1页Screening Vibrating screensPrinciples--Vibrating screens save space and weight and operate on little power because the screening surface may be actuated by vibrating, gyrating or pulsating movement of small amplitude, but at frequencies that normally exceed 3,000/min.Selection of Proper Vibration Sereen--Be sure the screen supplier knows all details of the application. The centrifugal force factor, or combination of frequency of vibration (speed) and amplitude (throw), may affect performance of any vibrating screen. Also, a correct combination of slope and direction of mechanism rotation is vital for inclined screens. Usually, the larger the opening, the greater the amplitude needed for a screen.If the throw is too small, the material may clog or wedge in the openings. Increasing the throw beyond what is required to prevent blinding or plugging does not necessarily increase the life of the bearings and reduce screening efficiency. Increased rate of travel permits more tonnage to be passed over the screen per unit of time. For a given tonnage, a faster rate of travel results in a thinner bed of material and high screening efficiency.Maximum slope is reached when the material travels too fast for the fines to penetrate the ribbon of material and reach the apertures in the screen cloth. At this point an excessive amount of fine material passes over the screen with the oversize, resulting in poor efficiency.When an existing screen is to be used for an application other than that for which it was originally intended, check with the Supplier to see if any of the operating characteristics need modification and if the the screen is structurally suitable for the new application.The operator can get the correct vibrating screen by providing the supplier with the following information:∙Maximum tons per hour to be screened, including any circulating load or any surges in the feed rate.∙ A complete size consist or sieve analysis of the material or, if available, an estimated analysis.∙Type of material and weight per cubic foot in broken state.∙Separations desired on each deck.∙Surface moisture carried by the material if screening is to be dry or amount of water with feed if wet.∙Special operating requirements or conditions such as temperature, abrasiveness, corrosiveness or other physical characteristics of the feed,efficiency or product requirements which determine selection of screening surface, or installation problems which affect screen size selection or capacity. General Types --Vibrating screens may be divided into two main classes: mechanically-vibrated and electrially-vibrated. The former can be subdivided into classes based on how the vibration is produced--by eccentrics; by unbalanced weight; by cams or bumpers. They can also be subdivided as inclined and horizontal.Sizes --Vibrating screens are made in standard sizes of from 12 in. to 10 ft wide and from 2 1/2 ft to 28 ft long. Common practice dictates that the length of the screen should be 2.5 times the width for dry screening. For wet screening, wider and shorter screen is best. Screens for scalping ahead of primary crushers, operate at a slope of from 12 degrees to 18 degrees and have openings as large as 11-in. square. The eccentric throw for openings from 5 to 11 in. is usually 1/2 in.; for openings from 3 to 5 in. about 3/8 in.; and for smaller openings 1/4 in. The screening surface consists of a heavy cast desk, perforated steel with or without skid bars welded between the holes, rod deck, etc.The mechanical shaking screen comprises a rectangular frame, with perforated steel or wire cloth screening medium. It is usually inclined and suspended on loose rods or cables. These screens now are used mainly for special tasks of coarse screening, having given way to vibrating screens.Electrically-Heated Screens--Electrically heated screen cloth decks have afforded better screening and less dust. Modern or updated screening operations, now handling clays, limestone, potash, salts, phosphates and various hydroscopic materials, report minimum dust loss when equipped with heated screens. The controlling factor in this improvement is the electrically-heated screen doth deck. Any vibratory screen with fine opening (less than 1/2 in.) can be equipped with low volt-age-high amperage resistance heating.The principle of electric heating is based on the fact that small diameter wire of screen cloth (especially stainless steel) serves as a conductor, but offers resistance to a high-amperage current. This resistance causes heating of the wire when powerful transformer and specially designed bus bars connected to screen doth decks push up to 6,000 amps current into a circuit. The current is safe and shock-proof because voltage is low, ranging from approximately 1 1/2 to 16 volts. Workers can do their jobs around electrically-heated screens without special precautions.Heated screens are effective in preventing moisture content of material from causing buildup and blinding. The screen wire is kept at 100 degrees to 130 degrees F depending on character and tonnage of the material processed. This temperature is not high enough to weaken the wire cloth or screen structure, nor does it suffice to drive off moisture held in material. The warm wire stays dry, breaking the surface tension that otherwise would bind damp material to cold, damp metal. This differential orwarm, dry screen wire versus cold, damp material can be maintained economically through transformer control settings.With every opening in the heated screen mesh protected against blinding, there is no guesswork about what size particle will be delivered. A uniform, unvarying quality to meet tough specifications comes through day after day, no matter what the weather. (High humidity makes trouble with unheated screens.) Plants operating heated screens will have no trouble with excessive amounts of fine, dusty material that formerly sifted through reduced meshes on clogged screens.Service life of screen cloth is greatly increased when electric heating ends the punishment of old-fashioned cleaning methods, such as rough pounding or brushing. Blowtorch flames put too much heat in one spot and bouncing chains added to wear and tear. But, screens kept clean and open with electric heating reportedly are seldom mistreated and last up to eight times as long. Heated decks end the threat of pile ups and strains that can break the mesh.Economical operation of electric heating for screens requires one transformer for installations of up to three panels of screen cloth (maximum area 4- x 12-ft). Two transformers are used on longer decks. Any deck (top, center or bottom) can be heated. Electric heating is most desirable of all where a screen surface is hard to get at. Changing heated screens does not involve more unbolting than needed for ordinary screens.In specifying screens to deliver a uniform particle through heated mesh, the first thing to consider is weight per square foot of the wire cloth needed to set up appropriate resistance. Most calculations are based on square openings. Slotted openings must be identified as to width of clear opening, diameter of wire and number of wires per inch before weight per square foot can be found in any screen cloth manufacturer's catalog.Having determined the usable weight per square foot of screen cloth, the next step is to select the size of clear opening needed, making no allowance for reduction in this size as formerly was the case when material stuck to the wires. Heated wires will maintain the clear opening at all times, making it possible to screen finer without blinding.From a wire catalog, select a mesh weighing no more per square foot (can weigh less) than determined using the method above with the clear opening characteristics desired. This often turns out to be a more efficient screen because the wire diameter will be smaller and the percentage of the open area will be greater.For example, where a 1/8-in. clear opening was desired (but often blinded) on unheated screens, the wire diameter was 0.63 and the open area was 44 percent. The cloth weighed 1.43 lb/ft. 2. For a heated 3- x 12-ft screen, the weight must not exceed1.1 lb/ft2. Two options were found in cloth with 1/8-in. clear opening: wire diameter .054 weighing 1.09 lb/ft2providing 48.8 percent open area; and wire diameter .047 weighing 0.85 lb/ft2 with a 52.8 percent open area.Load conditions may make fine diameters of carbon steel wire inadequate. In such cases, stainless steel wire of larger diameter with greater load-carrying capacity will have the necessary resistance for good heating.Lighter wire with more open area yields higher tonnage and heated mesh stays open 100 percent. Two screen cloths connected in a series may be of different mesh sizes or clear openings, as long as they both weigh the same per ft2and do not exceed the weight allowed for that particular size of screen.With heated screens, major savings in pollution control are possible. Also moisture content of material is reportedly increased in a range of 5 to 8 percent. This moisture is added during or after crushing-grinding operations and holds down dust during transfer of material and passage over heated screens. Warm wire handles 5 to 8 percent moisture in stride. The cost of heating equipment and mist spraying reportedly is less than the cost of having bag towers and precipitators.振动筛的选择振动筛的选择原则：选择振动筛的原则是所选择的振动筛要节省空间、重量并且驱动的功率要小，因为筛选表面可以驱动并且发生振动。

机械制造及自动化专业毕业论文--圆形振动筛的设计

摘要本设计主要介绍了圆振动筛的国内外现状及其分类和特点，通过对振动筛工作原理的分析及工艺参数的选择与确定完成圆振动筛的总体设计。

并在确定了设计方案的基础上对电动机的选择、主要零部件的结构设计等做了进一步的研究。

振动筛分机械是近20年来得到迅速发展的一种新型机器，目前已广泛应用于采矿、冶金、水利电力、石油化工、煤炭、交通运输、建筑和铁道等工业部门中，用于完成各种不同的工艺过程。

最近几年，各国对振动筛分技术的研究很重视，如强化振动参数，设备大型化，筛机零部件的三化，自同部技术的推广应用，新筛机的出现等都是围绕着振动筛发展起来的。

设计首先分析论述了设计方案，包括振动筛的分类与特点和设计方案的确定；筛面物料的运动理论分析；其次进行了对振动筛的动力学分析及动力学参数的计算；合理设计振动筛的结构尺寸；进行了激振器的偏心块等设计与计算，包括原始的设计参数，电动机的设计；最后进行了主要零部件的设计与计算，包括轴承的选择与计算，皮带的设计计算与校核，轴的强度计算和校核，弹簧的设计计算。

关键词：振动筛结构筛分机械激振器AbstractThis design is mainly introduced the situation at home and abroad and the circle vibrating screen classification and characteristics, and through the analysis of the operation of vibrating screen and the process parameters of the selection and be sure to complete circle vibrating screen of the overall design. In the design plan and determined on the basis of the choice of motor, main parts of the structure design, further research.Vibration screening machines the past 20 years the rapid development of a new machine, has been widely used in industrial sectors of mining, metallurgy, water conservancy, electric power, petrochemical, coal, transport, construction and railway used to complete a variety of different process. In recent years, countries right vibration screening technology very seriously, such as the strengthening of vibration parameters, equipment, sieve machine parts, to promote the use of the same technology, the new screen, and so on are around the shaker development.At the first ,the design analysis expositions design program , including vibrating screen of classification and features and determine of design program; the movement theory analysis of sieve surface material ;at the second, the design analysis dynamics of vibrating screen and the calculation of dynamics parameter; reasonable design vibrating screen of structure size; conduct the design and calculation of stress vibration device of eccentric block, , including original design parameter, motor design; at last, conduct main parts design and calculation, including select and calculation of bearing , design calculation and check of belt , strength calculation and check of axis , design calculation of mechanical spring .Key words:Vibrator Construction Screening machine ShakerSignnature of Supervison:目录1绪论 (4)1.1引言 (4)1.2 国内外现状 (5)1.2.1振动筛国内外研究现状 (5)1.2.2振动筛国内外发展现状 (7)1.3本文的主要内容 (7)1.3.1前期准备 (7)1.3.2阅读振动筛设计的相关理论及方法 (8)1.3.3完成圆振动筛的设计 (9)2振动筛的总体设计 (10)2.1 引言 (10)2.2总体设计方案的初步拟定 (10)2.2.1振动筛的基本结构 (10)2.2.2工艺参数的选择与确定 (11)2.2.3振动筛筛面物料运动理论 (12)2.3 设计方案 (17)2.3.1运动学参数的确定 (17)2.3.2振动筛工艺参数的确定 (19)2.3.3动力学参数 (21)2.4本章小结 (23)3主要零部件的结构设计 (24)3.1引言 (24)3.2电动机的选择 (24)3.3轴承的选择与计算 (25)3.3.1轴承的选择 (25)3.3.2轴承的寿命计算 (26)3.4皮带的设计 (27)3.4.1选取皮带的型号 (27)3.4.2传动比 (27)3.4.3带轮的基准直径 (27)3.4.4带速 (27)3.4.5确定中心距和带的基准长度 (28)3.4.6小带轮包角 (28)3.4.7单根带的基本额定功率 (29)3.4.8带的根数 (29)3.4.9单根带的预紧力 (29)3.4.10单根带的轴压力 (29)3.5轴的设计 (30)3.5.1轴的设计特点 (30)3.5.2轴的常用材料 (30)3.5.3轴的强度验算 (30)3.6支承弹簧设计验算 (33)3.6.1弹簧刚度计算 (33)3.6.2计算弹簧钢丝直径 (33)3.6.3计算弹簧中径 (34)3.6.4计算弹簧圈数和节距 (34)3.6.5求解弹簧的间距和螺旋角 (34)3.6.6弹簧验算 (35)3.7筛箱的设计 (36)3.7.1侧板和横梁 (36)3.7.2筛箱结构的焊接 (36)3.7.3筛面的固定方法 (37)3.8本章小结 (37)4结论与展望 (38)4.1全文工作总结 (38)4.2进一步工作的展望 (38)参考文献 (40)致谢......................................................................................................................... 错误!未定义书签。

圆振动筛设计

河南机电高等专科学校毕业设计论文论文题目：（2Y A1530）圆振动筛分机设计—可移动小车的设计系部机电工程系专业机电一体化班级机电072班学生姓名丁小振学号070212224指导教师王志伟2010年3 月25 日摘要圆振动筛是一种做圆形振动、多层数、高效新型振动筛。

圆振动筛采用筒体式偏心轴激振器及偏块调节振幅，物料筛淌线长，筛分规格多，具有结构可靠、激振力强、筛分效率高、振动噪音小、坚固耐用、维修方便、使用安全等特点，该振动筛广泛应用于矿山、建材、交通、能源、化工等行业的产品分级。

随着国民经济和工业的快速发展，在矿山、建材环卫等行业中，对物料的筛分、脱水脱介的处理的质量要求越来越高。

现有的市场却不能够提供此类振动筛。

本设计在原有圆振动筛的设计基础上，对其主要的参数和机械性能进行了优化设计，并在其底座上设计了移动小车，以及在应用中需要注意的问题。

激振器采用新乡威猛生产的筒式激振器，重量轻且激振效果好。

主弹簧采用橡胶复合弹簧，噪声小，减振效果好、运行安全可靠。

采用普通的钢板筛面，筛分效果好，分级颗粒较好。

该圆振筛机处理能力强，筛分效率高，具有技术参数合理，结构强度、刚度高，运转可靠，噪音小，维修方便等特点。

关键词：振动筛移动小车激振器效率方便AbstractCircular Vibrating Screen is a kind of doing a circular v ibration, multi-number, high-performance new shaker.Circular Vibrating Screen used tube-ty pe eccentric shaft vibration exciter and partial block of conditioning amplitude, the material screen drip lines long, screening more than specifications, with structure, reliable, strong ex citing force, high screening efficiency, the vibration noise is small, rugged, maintenanceto facilitate the use of security features, the v ibrating screen is widely used in mining, building materials, transportation, energy, chemical industry products classification.With the rapid economic and industrial dev elopment, mining, building materials and sanitation and other sectors, the siev ing of the materials, treatment of dehydration-mediated removal quality requirements are increasing.Ex isting market is not able to provide such a shaker.The design in the original design of circular v ibrating screen, based on its main parameters and mechanical properties of optimized design and in its base to design a mobile cart, as well as in the application need to pay attention to.Exciter with Xinxiang mighty production of cylindrical exciter, light weight, and the excitation effect is good.The main spring with rubber compound spring, noise, v ibration reduction effect is good, safe and reliable e of ordinary steel sieve surface screening effect is good, better particle classification.The Circular sieve shaker processing capability, high screening efficiency, with technical parameters and reasonable, structural strength, high stiffness, operation reliability, noise is small, easy maintenance and so on.Key word: Shaker，The car driver, Scr eening, Efficiency，Easy目录1 绪论 (1)2 运动参数的选择 (4)2.1筛面倾角 (5)2.2振动方向角 (5)2.3振幅 (6)2.4振动次数 (6)2.5物料的速度 (6)3 振动工艺参数的计算 (8)3.1生产率的计算 (8)3.2筛面长和宽的确定 (9)3.3筛面的设计 (10)3.4 筛面开孔率的计算 (11)3.5 筛分效率计算 (11)4动力学分析和参数计算 (13)4.1振动筛动力学分析 (13)4.2单轴振动筛的工作状态 (17)4.3隔振弹簧的确定 (19)4.4激振器偏心质量偏心距 (20)5电动机的选择 (22)6筛箱的设计 (26)6.1侧板和横梁 (26)6.2筛箱结构的焊接 (26)6.3筛面的固定方法 (27)7V型带的设计 (28)8 激振器轴承的选用及校核 (32)8.1振动筛轴承的选择 (31)8.2轴承的校核 (33)9 移动小车的设计 (36)9.1实现功能 (36)9.2结构设计 (36)9.3设计中的注意事项 (38)10 振动筛安装与维护 (39)10.1 安装及调试 (40)10.2操作要点 (41)10.3维护与检修 (42)11 结论 (43)致谢 (44)参考文献 (45)1 绪论最近几年，节能、环保、减耗成了国家可持续发展的主要方向。

机械类毕业设计外文翻译范文

机械类毕业设计外文翻译、毕业设计（论文）外译文题目：轴承的摩擦与润滑10 月 15 日外文文献原文：Friction , Lubrication of BearingIn many of the problem thus far , the student has been asked to disregard or neglect friction . Actually , 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 andthe 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. Also , 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. As 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 addedenergy 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 alloys, and copper and tin iolite bearings are used with both soft and hardened 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 systems 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; this is called “unlubricated ”or dry sliding.Fluid-film lubrication. Interposing a fluid film that completely separates the sliding surfaces results in fluid-film lubrication. The fluid may be introduced intentionally as the oil in the main bearing of an automobile, or unintentionally, as in the case of water between a smooth tuber tire and a wet pavement. Although the fluid is usually a liquid such as oil, water, and a wide。

有关振动筛外文翻译

景德镇陶瓷学院毕业设计(论文)有关外文翻译院系：机械电子工程学院专业：机械设计制造及其自动化*名：***学号：************指导教师：***完成时间：2012-04-15说明1、将与课题有关的专业外文翻译成中文是毕业设计（论文）中的一个不可缺少的环节。

此环节是培养学生阅读专业外文和检验学生专业外文阅读能力的一个重要环节。

通过此环节进一步提高学生阅读专业外文的能力以及使用外文资料为毕业设计服务，并为今后科研工作打下扎实的基础。

2、要求学生查阅与课题相关的外文文献3篇以上作为课题参考文献，并将其中1篇（不少于3000字）的外文翻译成中文。

中文的排版按后面格式进行填写。

外文内容是否与课题有关由指导教师把关，外文原文附在后面。

3、指导教师应将此外文翻译格式文件电子版拷给所指导的学生，统一按照此排版格式进行填写，完成后打印出来。

4、请将封面、译文与外文原文装订成册。

5、此环节在开题后毕业设计完成前完成。

6、指导教师应从查阅的外文文献与课题紧密相关性、翻译的准确性、是否通顺以及格式是否规范等方面去进行评价。

变椭圆轨迹振动筛的动力学和筛选特性何小梅，刘楚生机械和电气工程学院，中国矿业大学科技，江苏省徐州市221116，中国摘要：根据恒床厚度的筛选过程振动筛理想运动特征被提出，提出了一个新的振动筛变椭圆跟踪。

准确的力学模型建立，根据所需的结构构造运动特征。

应用多种学位自由度振动理论、特点，分析振动筛的。

振动筛运动参数获得，它的运动轨迹有线性的，圆的，椭圆的。

振动筛的运动动态方程可通过计算机模拟得以有效的解决。

屏幕表面五个特殊的点的技术参数，包括振幅，运动速度和引发指数，是通过理论计算获得。

结果显示，新设计的振动筛的轨迹遵循理想的筛选运动。

筛分效率及处理能力可能因此而有效改进。

关键字：变椭圆轨迹；筛选过程与常量床厚度；动态模型；运动特性；筛选特征1介绍筛分操作是一个重要的煤矿处理组成部分。

振动筛是最广泛使用的筛选工具之一。

振动筛毕业设计

振动筛毕业设计振动筛毕业设计在工程领域中，振动筛是一种常用的筛分设备，广泛应用于矿山、冶金、建筑材料、化工等行业。

振动筛通过振动力将物料进行筛分，将不同粒度的物料分离出来，从而满足不同行业对物料粒度的要求。

本文将探讨振动筛的工作原理、设计要点以及在毕业设计中的应用。

首先，我们来了解一下振动筛的工作原理。

振动筛主要由筛箱、振动器、弹簧、减振器等部件组成。

当振动器激发振动力时，筛箱会产生振动，物料在筛箱上产生相对运动，从而实现物料的筛分。

振动筛的振动力可以根据物料的特性和筛分要求进行调节，以达到最佳的筛分效果。

在振动筛的设计中，有几个关键要点需要考虑。

首先是筛箱的设计。

筛箱的大小和形状会直接影响到物料的筛分效果。

一般来说，筛箱的长度要大于宽度，以保证物料在筛分过程中有足够的时间和空间进行筛分。

此外，筛箱的材质也需要考虑，一般选择耐磨性好、耐腐蚀性强的材料，以提高振动筛的使用寿命。

其次是振动器的设计。

振动器是振动筛的核心部件，它产生的振动力直接影响到筛分效果。

振动器的选择应根据物料的特性和筛分要求进行，一般有电机振动器和激振器两种类型。

电机振动器结构简单，使用方便，适用于小型振动筛；而激振器则适用于大型振动筛，具有振动力大、振动频率可调的特点。

此外，减振器的设计也是振动筛设计中需要考虑的因素之一。

振动筛在工作过程中会产生较大的振动力，如果不进行有效的减振处理，不仅会对设备本身造成损坏，还会对周围环境和工作人员的健康产生影响。

因此，在振动筛的设计中，需要合理选择减振器，以减小振动力的传递和减少振动筛的振动幅度。

振动筛在毕业设计中的应用也是一个重要的研究方向。

毕业设计是学生综合应用所学知识和技能进行实践的重要环节，而振动筛作为一种常用的筛分设备，其设计和优化对于工程领域的研究具有重要意义。

在毕业设计中，可以通过对振动筛的结构、振动力和筛分效果等方面进行研究，以提高振动筛的性能和效率。

例如，可以通过改变振动筛的筛网形状和尺寸，优化筛分效果。

机械振动毕业设计外文翻译(中文)[管理资料]

LabVIEW分析工业环境中机械振动的实际应用Ioan Lita, Daniel Alexandru Visan, Gelu Mujea, Dan GhitaElectronics and Computers Department, University of PitestiStr. Targul din Vale, , Pitesti, ROMANIAlita@., visan@摘要在简要的介绍机械振动的源头及其对工业环境的影响后，在本文提出一个新的机械振动的通用监测及分析系统。

在这项工作中提出的配置系统的目的是用于分析和监测的工业机器的机械振动。

该系统的主要有三部分：连接到个人电脑的数据采集板，振动传感器，在LabVIEW图形化编程环境下实现的分析和控制软件。

所提出的方案与其他类似的方案相比，它的主要优点是它所具有灵活性。

该软件相对其他机械振动分析软件容易操作得多，例如：地球动力学/振动监测系统;公路，桥梁或塔监控系统。

此外，该设备是很容易扩展到更多的传感器，可以安装迅速，具有友好的图形界面，但不昂贵。

1.引言监测环境振动的能力是重要的，无论是从研究的角度看，还是工业应用方面，如自适应控制，状态监测，工艺优化和质量控制。

直到今天，大量的工作已经完成，如在环境机械振动分析，工具等方面的监测和控制等等。

例如，有一种日益增长的趋势，指明建筑振动的临界值，限制值条件，临界值是指有干扰和不确定性下的振动水平，限制值是指可能振动干扰的振动水平。

这些值通常用在建筑规格，控制报告频率和预先计划的执行情况和减轻补救行动。

此外，在工业领域，这个类似的系统，在这项工作提出了允许各种机械的连续监测，提供信息服务，便于对故障或故障早期检测。

这样就能预防更进一步严重故障甚至损坏，要不可能会损害机器的性能或危及厂房及操作人员。

为监测环境和机器的状况，可以使用计算机的多种传感器。

在这方面的工作，它有简单，灵活，操作方便等优越性。

毕业设计---振动筛外文翻译

毕业设计---振动筛外文翻译Vibrating screens are designed to save space and weight while operating on minimal power。

This is achieved by using a screening surface that XXX。

gyrating。

or pulsating movementsof small amplitude。

XXX 3,000/XXX。

it is XXX of the n。

The centrifugal force factor。

which is a n of frequency of n (speed)and amplitude (throw)。

XXX。

XXX inclined screens。

Generally。

the larger the opening。

the greater the amplitude XXX.Page 2Screening Vibrating screensn and Maintenance--It pays to follow the XXX errors is to mount the screen XXX.Instead。

the screen should be XXX XXXof throw。

The screen should be XXX。

If the screen is to be used for wet screening。

it XXX.XXX。

it is XXX can cause difficult-to-correct problems。

while a screen that is not XXX may fail to perform up to XXX。

Instead。

the screen should be XXX XXX of throw。

机械类毕业设计外文翻译_New

机械类毕业设计外文翻译外文原文Options for micro-holemakingAs in the macroscale-machining world, holemaking is one of the most— if not the most—frequently performed operations for micromachining. Many options exist for how those holes are created. Each has its advantages and limitations, depending on the required hole diameter and depth, workpiece material and equipment requirements. This article covers holemaking with through-coolant drills and those without coolant holes, plunge milling, microdrilling using sinker EDMs and laser drilling.Helpful HolesGetting coolant to the drill tip while the tool is cutting helps reduce the amount of heat at the tool/workpiece interface and evacuate chips regardless of hole diameter. But through-coolant capability is especially helpful when deep-hole microdrilling because the tools are delicate and prone to failure when experiencing recutting of chips, chip packing and too much exposure to carbide’s worst enemy—heat.When applying flood coolant, the drill itself blocks access to the cutting action. “Somewhere about 3 to 5 diam eters deep, the coolant has trouble getting down to the tip,” said Jeff Davis, vice president of engineering for Harvey Tool Co., Rowley, Mass. “It becomes wise to use a coolant-fed drill at that point.”In addition, flood coolant can cause more harm than good when microholemaking. “The pressure from the flood coolant can sometimes snap fragile drills as they enter the part,” Davis said.The toolmaker offers a line of through-coolant drills with diameters from 0.039" to 0.125" that are able to produce holes up to 12 diameters deep, as well as microdrills without coolant holes from 0.002" to 0.020".Having through-coolant capacity isn’t enough, though. Coolant needs to flow at a rate that enables it to clear the chips out of the hole. Davis recommends, at a minimum, 600 to 800 psi of coolant pressure. “It works much better if you have higher pressure than that,” he added.To prevent those tiny coolant holes from becoming clogged with debris, Davis also recommends a 5μm or finer coolant filter.Another recommendation is to machine a pilot, or guide, hole to prevent the tool from wandering on top of the workpiece and aid in producing a straight hole. When applying a pilot drill, it’s important to select one with an included angle on its point that’s equal t o or larger than the included angle on the through-coolant drill that follows.The pilot drill’s diameter should also be slightly larger. For example, if the pilot drill has a 120° included angle and a smaller diameter than a through-coolant drill with a 140°included angle, “then you’re catching the coolant-fed drill’s corners and knocking those corners off,” Davis said, which damages the drill.Although not mandatory, pecking is a good practice when microdrilling deep holes. Davis suggests a pecking cycle that is 30 to 50 percent of the diameter per peck depth, depending on the workpiece material. This clears the chips, preventing them from packing in the flute valleys.Lubricious ChillTo further aid chip evacuation, Davis recommends applying an oil-based metalworking fluid instead of a waterbased coolant because oil provides greater lubricity. But if a shop prefers using coolant, the fluid should include EP (extreme pressure) additives to increase lubricity and minimize foaming. “If you’ve got a lot of foam,” Davis noted, “the chips aren’t being pulled out the way they are supposed to be.”He added that another way to enhance a tool’s slipperiness while extending its life is with a coating, such as titanium aluminum nitride. TiAlN has a high hardness and is an effective coating for reducing heat’s impact when drilling difficult-to-machine materials, like stainless steel.David Burton, general manager of Performance Micro Tool, Janesville, Wis., disagrees with the idea of coating microtools on the smaller end of the spectrum. “Coatings on tools below 0.020" typically have a negative effect on every machining aspect, from the quality of the initial cut to tool life,” he said. That’s becaus e coatings are not thin enough and negatively alter the rake and relief angles when applied to tiny tools.However, work continues on the development of thinner coatings, and Burton indicated that Performance Micro Tool, which produces microendmills and microrouters and resells microdrills, is working on a project with others to create a submicron-thickness coating. “We’re probably 6 months to 1 year from testing it in the market,” Burton said.The microdrills Performance offers are basically circuit-board drills, which are also effective for cutting metal. All the tools are without through-coolant capability. “I had a customer drill a 0.004"-dia. hole in stainless steel, and he was amazed he could do it with a circuit-board drill,” Burton noted, adding th at pecking and running at a high spindle speed increase the drill’s effectiveness.The requirements for how fast microtools should rotate depend on the type ofCNCcharged EDM wire. The fine-hole option includes a W-axis attachment, which holds a die that guides the electrode, as well as a middle guide that prevents the electrode from bending or wobbling as it spins. With the option, the machine is appropriate for drilling hole diameters less than 0.005".Another sinker EDM for micro-holemaking is the Mitsubishi VA10 with afine-hole jig attachment to chuck and guide the fine wire applied to erode the material. “It’s a standard EDM, but with that attachment fixed to the machine, we can do microhole drilling,” said Dennis Powderly, sinker EDM product manager for MC Machinery Systems Inc., Wood Dale, Ill. He added that the EDM is also able to create holes down to 0.0004" using a wire that rotates at up to 2,000 rpm.Turn to TungstenEDMing is typically a slow process, and that holds true when it is used for microdrilling. “It’s very slow, and the finer the details, the slower it is,” said , president and owner of Optimation Inc. The Midvale, Utah, company builds Profile 24 Piezo EDMs for micromachining and also performs microEDMing on a contract-machining basis.Optimation produces tungsten electrodes using a reverse-polarity process and machines and ring-laps them to as small as 10μm in diameter with 0.000020" roundness. Applying a 10μm-dia. electrode produces a hole about 10.5μm to 11μm in diameter, and blind-holes are possible with th e company’s EDM. The workpiece thickness for the smallest holes is up to 0.002", and the thickness can be up to 0.04" for 50μm holes.After working with lasers and then with a former EDM builder to find a better way to produce precise microholes, Jorgense n decided the best approach was DIY. “We literally started with a clean sheet of paper and did all the electronics, all the software and the whole machine from scratch,” he said. Including the software, the machine costs in the neighborhood of $180,000 to $200,000.Much of the company’s contract work, which is provided at a shop rate of $100 per hour, involves microEDMing exotic metals, such as gold and platinum for X-ray apertures, stainless steel for optical applications and tantalum and tungsten for the electron-beam industry. Jorgensen said the process is also appropriate for EDMing partially electrically conductive materials, such as PCD.“The customer normally doesn’t care too much about the cost,” he said. “We’ve done parts where there’s $20,000 [in time and material] involved, and you can put the whole job underneath a fingernail. We do everything under a microscope.”Light CuttingBesides carbide and tungsten, light is an appropriate “tool material” formicro-holemaking. Although most laser drilling is performed in the infrared spectrum, the SuperPulse technology from The Ex One Co., Irwin, Pa., uses a green laser beam, said Randy Gilmore, the company’s director of laser technologies. Unlike the femtosecond variety, Super- Pulse is a nanosecond laser, and its green light operates at the 532-nanometer wavelength. The technology provides laser pulses of 4 to 5 nanoseconds in duration, and those pulses are sent in pairs with a delay of 50 to 100 nanoseconds between individual pulses. The benefits of this approach are twofold. “It greatly enhances material removal compared to other nanosecond lasers,” Gilmore said, “and greatly reduces the amount of thermal damage done to the workpiece material” because of the pulses’ short duration.The minimum diameter produced with the SuperPulse laser is 45 microns, but one of the most common applications is for producing 90μm to 110μm holes in diesel injector nozzles made of 1mm-thick H series steel. Gilmore noted that those holes will need to be in the 50μm to 70μm ra nge as emission standards tighten because smaller holes in injector nozzles atomize diesel fuel better for more efficient burning.In addition, the technology can produce negatively tapered holes, with a smaller entrance than exit diameter, to promote better fuel flow.Another common application is drilling holes in aircraft turbine blades for cooling. Although the turbine material might only be 1.5mm to 2mm thick, Gilmore explained that the holes are drilled at a 25° entry angle so the air, as it comes out of the holes, hugs the airfoil surface and drags the heat away. That means the hole traverses up to 5mm of material. “Temperature is everything in a turbine” he said, “because in an aircraft engine, the hotter you can run the turbine, the better the fuel economy and the more thrust you get.”To further enhance the technology’s competitiveness, Ex One developed apatent-pending material that is injected into a hollow-body component to block the laser beam and prevent back-wall strikes after it creates the needed hole. After laser machining, the end user removes the material without leaving remnants.“One of the bugaboos in getting lasers accepted in the diesel injector community is that light has a nasty habit of continuing to travel until it meets anothe r object,” Gilmore said. “In a diesel injector nozzle, that damages the interior surface of the opposite wall.”Although the $650,000 to $800,000 price for a Super- Pulse laser is higher than a micro-holemaking EDM, Gilmore noted that laser drilling doesn’t require electrodes. “A laser system is using light to make holes,” he said, “so it doesn’t have a consumable.”Depending on the application, mechanical drilling and plunge milling, EDMing and laser machining all have their place in the expanding microm achining universe. “People want more packed into smaller spaces,” said Makino’s Kiszonas.中文翻译微孔的加工方法正如宏观加工一样，在微观加工中孔的加工也许也是最常用的加工之一。

毕业设计(论文)-振动筛设计

毕业设计（论文）-振动筛设计摘要对双轴直线振动筛进行分析从整体布局到个别零件的选用都进行了设计包括筛箱筛面的设计和固定激振器的形状支撑方案等等还包括轴偏心块等零件的设计采用双电机带动使得两个轴上的偏心块同步另一方面采用了座式结构淘汰了以往悬挂式的方式使得结构更加安全占地面积更小本产品为生产能力为855th的中型振动筛对于筛框的材料有比较高的要求现采用高强度和高冲击韧性的钢材不仅仅提高了筛框的耐用度还减轻了整个结构的重量对弹簧的选则等许多方面也带来了很多的方便设计中还包括对连接和固定件的选用采用十字轴联轴器和轮胎联轴器并用螺栓连接代替焊接减小了焊接时应力对它的影响关键词振动筛激振器偏心块横梁This article is carried out mainly according to the design of the two axle vibrating separators of straight line from overall layout go to individual element choose to go on improving include sifting the design of case and compass screen surface and the regular shape of vibrator support the design of scheme and so on still include the design of the elements such as axle and partial piece Drive with double generator positive drive makes two partial pieces synchronous has adopted on the other hand to use type structure have superseded the way of former overhead suspension make structure more safe it is less to cover an area of area This design product has higher requirement for the material of screen frame for productivity is the large scale vibrating separator of 80 th has now not only raised the durability of screen frame with the high-strength and high steel material of impact tenacity have still alleviated the weight of entire structure for spring choose to have also brought many conveniencesIn design still include for connection and regular choosing with the durable shaft coupling of cross axle replace welding with bolt connection it is little to reduce welding stress for its influenceKeyword Vibrating separator vibrator partial piece beam摘要IAbstract II第1章绪论 111 课题研究背景及意义 113 振动筛在国内外的发展现状 314 振动筛的工作原理分类及特点 5com 振动筛的工作原理 5com 直线振动筛的工作原理 6第2章总体方案的设计821 振动筛方案的列举822 方案分析823 方案确定824 振动筛各部分实现形式8com 筛箱 8com 筛面 11com 激振器14com 支撑形式与隔振装置 15第3章双轴直线振动筛的参数计算1831 振动筛上物料的运动分析和工艺参数的选择18 com 直线振动面上的物料运动分析18com 工艺参数的选择2332 总体设计计算步骤24com 计算振动筛筛面面积 24com 振动次数的计算25com 物料运动速度的计算 25com 验算生产率26com 估算振动筛的重量26com 激振器偏心块的质量及其偏心距的确定26 com 隔振弹簧刚度的确定 27com 电动机的选择2733 橡胶弹簧的设计29第4章激振器的设计3241 轴的计算与设计32com 初步估算轴的最小直径32com 轴的各段长度的直径设计32com 对轴的强度校核3342 轴承的计算与选择3643 密封件的设计计算3644 偏心块的设计与计算3645 联轴器的设计 37com 联轴器的类型选择37com 规格的选择与计算3846 键的选择38com 轴与偏心块连接处键的选择与校核38 com 轴与联轴器的连接处键的选择与校核 38 第5章筛箱的结构设计3951 筛箱的结构3952 螺栓的强度校核4053 筛框横梁校核 41com 横梁受力分析41com 横梁强度计算42com 横梁固有频率的验算 42结论43致谢44参考文献45CONTENTSAbstract IChapter 1 Introduction 111 Background and significance of the research 113 Shaker current development at home and abroad 314 Shaker works classification and characteristics 5com Shaker works 5com The working principle of linear vibrating screen 6 Chapter 2 The overall program design 821 Shaker program list 822 Project Analysis 823 Program to determine 824 Realization of the various parts of shaker 8com Screen Box 8com Screensurface11com Exciter 14com Support form and isolation devices 15Chapter 3 Dual-axis linear vibrating screen parameter alculation 18 31 Shaker on the movement of materials and process selection 18 com Linear vibration analysis of the surface 18com Selection Process Parameters 2332 Design calculation steps 24com Calculation of shaker screen surface area 24com Calculation of vibration frequency 25com Calculation of material velocity 25com Checking productivity 26com Estimating the weight of shaker 26com Exciter and eccentric block the quality 26com Spring stiffness of isolation 27com Motor Selection 2733 The design of rubber springs 29Chapter 4 Design exciter 3241 Calculation and Design of Shaft 32com Preliminary estimates of the minimum diameter of shaft 32 com Dual-axis length of the diameter of each design 32com Stress Analysis on the axis 3342 Calculation and selection of bearings 3643 Design and calculation of seals 3644 The design and calculation eccentric 3645 Design of coupling 37com Select the type of coupling 37com Selection and calculation specifications 3846 Key Selection 38com Shaft and eccentric choice of key junctions 38 com Shaft and the coupling selection key junction 38 Chapter 5 Design sieve box 3951 The structure of sieve box 3952 Bolt strength check 4053 Check of screen box beams 41com Beam Stress Analysi 41com Calculation of beam intensity 42com Checking the natural frequency of beam 42 Conclusion 40Acknowledgement 44References 45第1章绪论11 课题研究背景及意义随着工业的发展筛分在国民经济中应用越来越广泛在煤炭冶金化工医药轻工环保等许多部门筛分作业是重要的生产环节之一对于矿物加工行业如选矿场或选煤场大批筛分机械正担负者分级脱水脱泥脱介甚至按质量分选的艰巨任务就煤炭加工而言筛分技术也显得尤为重要筛分机械不仅用于生产粒度水分和灰分等指达标到用户要求的煤炭产品而且在实现煤炭资源的合理利用和保护环境及为煤炭企业创造经济效益等方面都发挥着重要的作用本次设计的矿用同步直线振动筛由于其优良的工作特点振动强度大分选效果好结构简化噪音较低机器润滑和检修等日常维护工作减少设备的故障率降低创造了可观的经济效益因此进行同步直线振动筛的设计具有重大的现实与经济意义同时通过毕业设计让我学道了很多知识不但锻炼了独立思考的能力而且提高了自我的设计理念[1]12 振动筛的发展史用筛分机把碎散物料筛分成不同的颗粒已经有悠久的历史从英国煤炭工业的文献记载在1589年提到煤的筛分为了向市场提供各种颗粒的商品煤广泛的对煤进行筛分是到19世纪下半业才盛行起来固定筛是古老的筛分机当时有的固定筛用若干木条构成也叫棒筛后来出现了有传动机构的棒条筛这就是沿用至今的辊轴筛为满足工业生产的需要圆筒筛摇动筛和振动筛也先后问世[7]与固定筛相比虽然辊轴筛圆筒筛和摇动筛的工作效率有较大的改善而且仍不失为结构简单和工作可靠但是却步能满足生产发展的需要因此早在60年代这些筛子在我国就开始被逐渐淘汰固定筛不消耗动力和非常简单可靠的结构仍具有很强的生命力目前仍大量用于初步筛分振动筛采用抛射式筛分筛子每振动一次物料便被抛射一次相对筛面冲击一次被筛分物料的折中特点使得振动筛的筛分效率高生产能力大因此被广泛使用在振动筛产生以后人们开始重视建立和发展筛分理论早期的筛分理论形成于50年代初它是以单个颗粒为研究对象而发展起来的一般称为单颗粒运动理论该理论系统的描述了振动筛对物料进行抛射式筛分时单个颗粒的运动情况进而提出了筛分机特性值即振动强度K和筛分特性值即抛射强度经过长期实践人们发觉按照上述筛分理论设计的振动筛对细物料进行筛分时的生产能力太小遂意识到以单个颗粒物料的运动状态代表成群的物料运动状态具有交大的片面性随着研究工作的深入自1965年开始逐步建立起颗粒在筛面上的运动理论该理论以力群为研究对象根据物体在碰撞时传递能量的原理提出了筛面上整个料层中不同位置颗粒的速度变化规律突破了单颗料理论关于振动强度小于33的临界值在此基础上建立了薄层筛分法和变倾角筛分法研制出等厚振动筛用统计学方法研究碎散物料在筛面上透筛概率称为概率筛分理论该理论是由瑞典的摩根森于1951年最先提出的故在该理论指导下设计的振动筛称为摩根森概率筛[8]在力群运动理论的知道下近代振动筛的抛射强度和振动强度普遍提高如德国和美国直线振动筛K值达44有的甚至达67值达35以上振动概率筛K值达55～7弛张筛K值甚至达到30这些参数强化的振动筛适应了近代筛分作业的特点细粒物料增多水分和黏性增大以及筛分粒度下降和要求的分级脱水效率提高等随着工业企业的发展和筛分机设计制造技术的进步自70年代以来世界上一些国家先后研制出了大型振动筛筛宽在36m以上的已不罕见如日本身刚所生产的振comcom产的振动筛宽达55m面积约为50振动筛大型化标志着筛分机技术已达到先进水平零部件标准化通用化和产品系列化生产专业化是近代机械工业的重要标志筛分机械也不例外com产的USK圆振动筛和USL直线振动筛其激振器可以通用同一个筛框既可以装分级筛面也可装脱水筛面又如美国振动筛其基形已经稳定主要力量放在改进结构简化制造和应用新技术的方面有的筛子除激振器外筛框也作成单体结构可以在现场组装极大地方便了制造运输和维修前苏联早在60年代中期就组织了筛分机产品整顿统一基型减少杂乱型号在此基础上提高产品的系列化程度国外许多筛分机械公司都是科研设计制造和销售的联合体专业化程度高产品继承性好经过多年改进使产品逐步完善和提高[9]13 振动筛在国内外的发展现状建国50多年来我国的筛分设备走过了一个从无到有从小到大从落后到先进的发展过程前后经历了测绘仿制自行研制和引进提高3个阶段1 仿制阶段上世纪50年代我国的筛分设备极为落后生产上使用的都是从前苏联引进的TYII型圆振动筛波兰的Wp1型和Wp2型吊式直线振动筛为适应生产的发展国内各个制造单位通过对以上几种进口筛机进行测绘仿制形成了国产型号为SZZ系列的自定中心筛SZ系列的惯性筛和SSZ 系列的直线筛等初步奠定了我国筛分机械的基础2 自行研制阶段1967年由洛阳矿山机械研究所鞍山矿山机械厂北京煤矿设计院沈阳煤矿设计院平顶山选煤设计研究院组成了联合设计组制定了我国第一个煤用单双轴振动筛系列型谱并进行了ZDM DDM 系列单轴振动筛和ZSM DSM 系列双轴振动筛的产品设计工作1980年鞍矿厂完成了这四种基型筛的制造并通过了技术鉴定在工业上得到了广泛的应用这标志着我国筛分机械走上了自行研制发展的道路3 引进提高阶段上世纪80年代以来冶金和煤炭系统不断从国外引进先进的振动筛产品在煤炭行业山东兖州矿务局兴隆庄选煤厂引进了美国RS公司的TI 倾斜筛和TH 水平筛河北开滦矿务局各庄选煤厂引进了德国KHD公司制造的USK 圆振动筛USL直线振动筛山西矿务局选煤厂和淮北矿务局临涣选煤厂从日本神户制钢所引进的H L W型直线振动筛等这些筛机技术参数先进结构合理工作平稳可靠耐用基本上代表了2 0世纪70年代国际振动筛的技术水平在引进筛机产品的同时国内生产振动筛的专业厂鞍矿厂先后派谴专业技术人员去美国和德国进行技术考察并进行技术引进1980年鞍矿厂从美国RS公司引进TI和TH型振动筛制造技术转化为国内型号定为YA系列圆振动筛和ZKX系列直线振动筛在国内得到广泛应用此外1986年洛矿厂也从日本神户制钢所引进了HLW型振动筛制造技术转化后国内型号定为ZK系列振动筛该筛结构紧凑重量轻最大规格的筛分面积达27m2是当时国内最大的直线振动筛国外振动筛产品和制造技术的引进拓宽了我国筛分机械设计制造人员视野他们从中了解和学习到了先进国家设计制造振动筛的理论方法设计技术制造工艺生产管理业务水平也大大提高普通振动筛是采用中等料层厚度筛分法进行筛分然而随着筛分技术的发展新的筛分理论不断出现相应生产出新的筛分设备于此同时我国筛分机械的制造水平也有了很大的提高对以往工程中常用的振动筛大都采用单质体集中质量力学模型对有二次隔振功能的振动筛和弹性连杆式振动筛通常采用双质体集中质量力学模型目前一般采用刚性平板力学模型进行解析求解研究振动筛结构强度刚度和各阶固有模态时也采用连续体力学模型对于大型振动筛结构的弹性体力学模型目前大都采用离散化数值方法例如有限元模态分析法从发展的趋势看振动筛的减振是利用继电器控制和单板计算机控制共振振幅用继电器控制虽然减振效果好但线路复杂调试困难线圈容易出现故障所以目前应用受到制如果用单板计算机控制实验表明可以限制共振振幅为正常工作时振幅的115倍以内国内外一般采用激振电机但由于激振电机与筛箱一起振动所以要求电机具有较高的耐振性能目前我国筛分机械的生产已形成较大规模主要生产厂家有30多个可供应200多个品种年累计产量2000台左右产值近亿元基本上满足了各部门对筛分机械的要求14 振动筛的工作原理分类及特点com 振动筛的工作原理将颗粒大小不同的碎散物料群多次通过均匀布孔的单层或多层筛面分成若干不同级别的过程成为筛分理论上大于筛孔的颗粒留在筛面上称为该筛面的筛上物小于筛孔的颗粒透过筛孔称为该筛面的筛下物碎散物料的筛分过程可以看作由两个阶段组成一是小于筛孔尺寸的细颗粒通过粗颗粒所组成的物料层到达筛面二是细颗粒透过筛孔要想完成上述两个过程必须具备最基本的条件就是物料和筛面之间要存在着相对运动为此筛箱应具有适当的运动特性一方面使筛面上的物料层成为松散状态另一方面使堵在筛孔上的粗颗粒闪开保持细颗粒透筛之路畅通实际的筛分过程是大量粒度大小不同粗细混杂的碎散物料进入筛面后只有一部分颗粒与筛面接触而在接触筛面的这部分物料中不全是小于筛孔的细粒大部分小于筛孔尺寸的颗粒分布在整个料层的各处由于筛箱的振动筛上物料层被松散使大颗粒本来就存在的间隙被进一步扩大小颗粒乘机穿过间隙转移到下层或运输机上由于小颗粒间隙小大颗粒并不能穿过因此大颗粒在运动中位置不断升高于是原来杂乱无章排列的颗粒群发生了分离即按颗粒大小进行了分层形成了小颗粒在下粗颗粒居上的排列规则到达筛面的细颗粒小于筛孔者透筛最终实现了粗细粒分离完成筛分过程然而充分的分离是没有的在筛分时一般都有一部分筛下物留在筛上物中细粒透筛时虽然颗粒都小于筛孔但它们透筛的难易程度不同和筛孔相比颗粒越易和筛孔尺寸相近的颗粒透筛就较难透过筛面下层的颗粒间隙就更难振动筛一般分为三大类为圆运动振动筛直线运动振动筛和共振筛com 直线振动筛的工作原理直线振动筛是采用惯性激振器来产生振动的其振源有电动机带动激振器激振器有两个轴每个轴有一个偏心重而且以相反的方向旋转又称双轴振动筛当两个偏心重的圆盘转动时两个偏心重产生的离心力F在x轴的分量总是抵消在y 轴的分量相加其结果在y轴方向产生一个往复的激振力使筛箱在y轴方向上产生往复的直线轨迹振动如图1-1还有一种情况是振源采用的是振动电机这时需要布置两台他们的轴线方向必须与振动筛纵向轴线方向一致两台振动电机对称布置在筛箱的上方下部和两侧均可以1-1式中不平衡重的质量和单位为不平衡重块所产生的激振力单位为N转动时间单位为s不平衡重质心回转半径单位为m图1-1 振动筛原理图不平衡重的回转角速度单位为rads在振动方向上的激振力单位为N每个偏心块的质量单位为由上式可见双轴惯性激振器当作同步反向回转的时候产生定向的简谐力此力通过筛箱的质心使筛箱作定向往复直线振动直线振动筛的筛面倾角通常在以内筛面的振动振动角度一般为筛面在激振器的作用下作直线往复运动颗粒在筛面的振动下产生抛射与回落从而使物料在筛面的振动过程中不断向前运动物料的抛射与下落都对筛面有冲击致使小于筛孔的颗粒被筛选分离筛子的筛分效率及生产能力同筛面的倾角筛面的振动角度物料的抛射系数有关为了保证筛分效率高筛子的生产能力大必须选择合适的值第2章总体方案的设计21 振动筛方案的列举本次设计的直线振动筛用于煤的初步筛分振动频率为筛孔尺寸为生产率为受振动筛工作条件的要求确定两种设计方案方案一ZKX型直线振动筛如图2-1图2-1 ZKX型直线振动筛方案二ZKB型直线振动筛如图2-222 方案分析ZKB型直线振动筛是采用双电机驱动同步传动主振动弹簧为橡胶弹簧电机经轮胎式联轴器从筛箱侧直接带动两主轴转动传动结构简单维修方便运转中不产生较强的噪声和振动故障相对少些维修量小ZKX型直线振动筛主振弹簧为圆柱形螺旋弹簧采用箱式激振器单电机齿轮强迫传动运转中容易产生因加工装配方面存在误差而引发较强的噪图2-2 ZKB型直线振动筛声和振动同时由于激振箱内使用稀油润滑回转轴的密封要求比较高安装技术要求也较高维修质量难以保证ZKB型振动筛常见故障轮胎式联轴器的胶皮损坏主振橡胶弹簧易坏ZKX型振动筛常见故障噪声严重筛箱后箱板筛板下面的底梁振裂电动机轴断裂电动机经常烧坏电机底座螺栓被振断电机支撑架断裂激振器传动齿轮及轴承易损坏主振弹簧折断运转时还会出现跑料现象23 方案确定综合上述两种方案ZKB型振动筛是采用双电机驱动同步传动主振动弹簧为橡胶弹簧选用块偏心式激振器万向传动轴等先进高可靠性部件筛箱结构设计合理具有整体刚度大参数选择合理维护方便筛分效率高运转中不产生较强的噪声和振动等优点所以采用ZKB型直线振动筛24 振动筛各部分实现形式com 筛箱筛箱是筛子的承载部件由筛框及固定在它上面的筛面组成它是由侧板横撑加强板和横梁组合而成侧板是用钢板制成利用横梁将两块连接起来使筛框成整体结构侧板用以传递激振力激振器用螺栓连接在测板上为了加强侧板的刚度在测板两侧采用厚的钢板图2-3 振动筛简图侧板和横梁是筛框主要的受力部件由于筛箱是借助侧板支承所以侧板承受着物料和筛箱的重量并将激振力传递到筛框的各部分横梁承受筛板和物料的重量及它在工作中的惯性力横梁可以采用工字钢无缝钢管箱型梁和压型梁等几种采用槽钢作横梁由于梁的弯矩和长度平方成正比所以从强度观点来看筛箱的宽度不宜过大目前一般的筛箱很少大于25m1 筛箱部件的连接筛箱的部件给料槽横梁和横撑原来是焊接在筛帮上的但是这种焊接结构易产生局部应力集中在工作一定时间后常常导致破裂近年来为提高承载能力都改用铆钉或螺栓连接2 筛箱的支撑筛子安装方式取决于现场的条件或是架在机座上或是悬吊在承重结构上目前座式筛子占多数因为这种支撑方式比较简单对厂房的高度要求较低对筛子也没有特殊的安全要求但是要传给地基一定的水平力和垂直力3 筛框的材质我国目前一般采用A3碳素钢这种材料的可焊性良好但弹性和冲击韧性较低因此最好采用A5普通碳素钢对于大型筛子应该采用高强度和高冲击韧性的钢材其常用的材料是16Mn或锅炉钢板采用优质钢材可以提高材料的强度而且还能减轻筛框的重量对筛箱结构能带来一定好处com 筛面筛面是筛子的主要工作部件其性能的好坏不但影响生产率和筛分效率而且对延长筛分机的使用寿命提高作业率和降低生产成本有重大意义筛分机对筛面的基本要求是有足够的强度最大的有效面积筛孔总面积与整个面面积之比耐腐蚀耐磨损有最大的开孔率筛孔不易堵塞在物料运动时与筛孔相遇的机会较多前一种要求影响工作的可靠性和使用寿命后面三种要求关系到筛子的工作效果筛面的开孔率为筛孔总面积与筛面面积的比值用百分比来表示开孔率越大颗粒在每次与筛面接触时透过筛孔的机会就越多从而可以提高单位面积的生产率和筛分效率开孔率与筛孔的形状筛丝的直径有关筛丝直径小开孔率增大但筛丝太小强度不够影响筛面的使用寿命筛面的材质要具有耐磨损耐疲劳和耐腐蚀的性质用作大快分级筛面时采用高碳钢强烈冲击的筛面可选用高锰钢制作应用这些材质制作筛面时必须淬火处理以提高硬度和耐磨效果用于脱介脱水脱泥等湿式筛分作业时通常采用不锈钢筛面较适宜近年来随着科学技术的发展聚氨酯橡胶筛面现实了他的优越性使用寿命长不易堵筛筛孔噪音小但是价值昂贵1 筛面种类与选择常用的筛面有筛板筛网条缝筛和网状丝布四种前两种主要用在煤炭的分级筛分上后两种用在洗煤厂的脱水脱泥和脱介质中正确地选用和筛面就能提高筛分效果和工作的可靠性从而发挥筛子的应有能力筛板是最牢固的一种筛面主要用在大块物料的筛分上根据一般选煤厂使用的经验筛孔在25mm以上的大块分级应当采用筛板这样筛面的寿命较长对筛分效率都影响不大筛板的开孔率一般为40左右筛网突出的优点是开孔率大可达总筛网面积的70但是与筛板比较使用寿命较差所以一般只用在细颗粒的分级上在选煤厂往往用于筛孔小于30mm的煤炭分级筛网一般利用筛框两边的特制夹板从横向拉紧筛网拉紧可提高其使用寿命所以工作中应经常注意它的张紧程度条缝筛板广泛地用在煤的脱水脱泥和脱介质中我国选煤厂用条缝筛板的材质有铜和不锈钢 1Cr8Ni9 两种不锈钢筛板比铜筛板价格高倍但是它的强度大耐磨损使用寿命比铜筛板高倍脱水和脱介的效果也较好所以从减轻检修工作量提高筛分效果来看应用不锈钢筛板比较有利对于筛条式的筛板很多时候是筛条并无磨损或磨损不严重但由于穿条圆孔不规整筛条和穿条松动在工作中产生冲击使穿条断裂最后导致筛板损坏为了避免穿条的断裂可以提高穿条的材质采用能承受一定反复载荷的弹簧丝如60Si2Mn钢丝或中碳钢丝也可采用一些措施来避免穿条和筛条的相对运动如在筛板的两头筛条下边另焊角钢将穿条两头铆死或焊死在穿条圆圈处将筛条焊在一起等这些都能有效地增加筛板的使用寿命网状丝布一般用于煤泥脱水它类似编织粗布开孔率可达40～50网状丝布的种类很多常用的材质有不锈钢紫铜磷铜黄铜和尼龙等丝布的材质对其使用寿命影响很大当用作煤泥或末精煤脱水时铜丝布大约只能使用两个月而不锈钢和尼龙丝布的强度较大耐磨使用的寿命比铜丝布高约三倍尼龙丝布遇水有微小的膨胀伸长性较大当松弛而出现小窝同时亲水性也比不锈钢丝布大些所以泄水效率低在使用尼龙丝布时最好选用稍大一些的筛孔冲孔钢板固定就是把丝布直接固定在冲孔钢板上为了防止螺栓把丝布磨损在丝布上可垫以薄橡皮2 筛面的固定。

振动筛毕业论文外文文献翻译

Dynamics and screening characteristics ofa vibrating screen with variable elliptical traceHE Xiao-mei,LIU Chu-shengSchool of Mechanical and Electrical Engineering，China University of Mining ＆Technology,Xuzhou,Jiangsu 221116，ChinaAbstract: the ideal motion characteristics for the vibrating screen was presented , vibrating screen with variable elliptical trace was proposed. An accurate mechanical model was constructed according to the required structural motion features.Applying multi—degree—of-freedom vibration theory,characteristics of the vibrating screen was analyzed。

Kinematics parameters of the vibrating screen which motion traces were linear，circular or elliptical were obtained。

The stable solutions of the dynamic equations gave the motions of the vibrating screen by means of computer simulations.Technological parameters，including amplitude，movement velocity and throwing index，of five specific points along the screen surface were gained by theoretical calculation .The results show that the traces of the new designed vibrating screen follow the ideal screening motion 。

(完整word版)圆振动筛设计正文

圆振动筛设计机械设计制造及其自动化张家良指导老师李慧摘要：本设计主要介绍了圆振动筛的分类与特点，通过对振动筛的动力学分析及动力学参数的计算，主要完成了圆振动筛的总体设计，电动机的选择以及传动方案的分析、比较与选择等内容。

在此基础上,对振动筛的结构尺寸、激振器的偏心块、驱动轴的结构尺寸以及其他主要零部件的设计计算与校核，另对弹簧的、轴承等的选择进行了详细的计算和说明。

关键词：圆振动筛；激振器；设计引言从井下或露天采矿开采出来的或经过破碎的物料，是以各种大小不同的颗粒混合在一起的.在选矿厂、选煤厂和其它的工业部门中，物料在使用或进一步处理前，常常需要分成粒度相近的几种级别。

物料通过筛面的过孔分级称为筛分。

筛分所用的机械称为筛分机械.在选矿厂和选煤厂中应用的筛分机械有很多种结构型式，如固定格筛、弧形筛、旋造简单、生产能力大,筛分效率高等优点,因而在选矿厂、选煤厂及其它工业部门中已被广泛用于分级，脱水,脱介和脱泥作业。

共振筛在生产实践中也取得较好的效果，但因具有较大的冲击裁荷，故其机件(如横梁与侧板)容易损坏.须进一步研究和改进。

随着煤矿开采能力和入洗原煤量的提高，作为物料分级筛选的主要设备-—振动筛也不断向大型化发展。

圆振动筛是一种做圆形振动、多层数、高效新型振动筛。

1振动筛筛面物料运动理论1.1筛上物料的运动分析由文献［1]可知关于筛上物料的分析,如图1所示：振动筛运动学参数(振幅、振次、筛面倾角和振动方向角）通常根据所选择的物料运动状态选取.筛上物料运动状态直接影响振动筛的筛分效率和生产率,所以为合理地选择筛子的运动参数，必须分析筛上的物料的运动特性。

图1 圆振动筛上物料运动圆振动筛的筛面做圆运动或近似于圆运动的振动筛,筛面的位移方程式可用下式来表示:ωϕcosϕ-=x-︒=t （1）-=cosA)180Acos(Aϕsinωϕ=y=︒=t （2)-sin(AA)sin180A式中：A——振幅；ϕ——轴之回转相角,ϕ=ωt；ω--轴之回转角速度；t—-时间.求上式中的x和y 对时间t的一次导数与二次导数，即得筛面沿x和y方向上的速度和加速度：ωωsin A v X =t （3）ωωcos A v y =t （4）ωωcos 2A a X =t （5）ωωsin 2A a y -=t （6）由运动特征，来研究筛子上物料的运动学。

机械专业毕业设计外文翻译--振动的定义和术语

翻译：英文原文Definitions and Terminology of VibrationvibrationAll matter-solid, liquid and gaseous-is capable of vibration, e.g. vibration of gases occurs in tail ducts of jet engines causing troublesome noise and sometimes fatigue cracks in the metal. Vibration in liquids is almost always longitudinal and can cause large forces because of the low compressibility of liquids, e.g. popes conveying water can be subjected to high inertia forces (or “water hammer”) when a valve or tap is suddenly closed. Excitation forces caused, say by changes in flow of fluids orout-of-balance rotating or reciprocating parts, can often be reduced by attention to design and manufacturing details. Atypical machine has many moving parts, each of which is a potential source of vibration or shock-excitation. Designers face the problem of compromising between an acceptable amount of vibration and noise, and costs involved in reducing excitation.The mechanical vibrations dealt with are either excited by steady harmonic forces ( i. e. obeying sine and cosine laws in cases of forced vibrations ) or, after an initial disturbance, by no external force apart from gravitational force called weight ( i.e. in cases of natural or free vibrations). Harmonic vibrations are said to be “simple” if there is only one frequency as represented diagrammatically by a sine or cosine wave of displacement against time.Vibration of a body or material is periodic change in position or displacement from a static equilibrium position. Associated with vibration are the interrelated physical quantities of acceleration, velocity and displacement-e. g. an unbalanced force causes acceleration (a = F/m ) in a system which, by resisting, induces vibration as a response. We shall see that vibratory or oscillatory motion may be classified broadly as (a) transient; (b) continuing or steady-state; and (c) random.Transient Vibrations die away and are usually associated with irregulardisturbances, e. g. shock or impact forces, rolling loads over bridges, cars driven over pot holes-i. e. forces which do not repeat at regular intervals. Although transients are temporary components of vibrational motion, they can cause large amplitudes initially and consequent high stress but, in many cases, they are of short duration and can be ignored leaving only steady-state vibrations to be considered.Steady-State Vibrations are often associated with the continuous operation of machinery and, although periodic, are not necessarily harmonic or sinusoidal. Since vibrations require energy to produce them, they reduce the efficiency of machines and mechanisms because of dissipation of energy, e. g. by friction and consequentheat-transfer to surroundings, sound waves and noise, stress waves through frames and foundations, etc. Thus, steady-state vibrations always require a continuous energy input to maintain them.Random Vibration is the term used for vibration which is not periodic, i. e. has no made clear-several of which are probably known to science students already.Period, Cycle, Frequency and Amplitude A steady-state mechanical vibration is the motion of a system repeated after an interval of time known as the period. The motion completed in any one period of time is called a cycle. The number of cycles per unit of time is called the frequency. The maximum displacement of any part of the system from its static-equilibrium position is the amplitude of the vibration of that part-the total travel being twice the amplitude. Thus, “amplitude” is not synonymous with “displacement” but is the maximum value of the displacement from the static-equilibrium position.Natural and Forced Vibration A natural vibration occurs without any external force except gravity, and normally arises when an elastic system is displaced from a position of stable equilibrium and released, i. e. natural vibration occurs under the action of restoring forces inherent in an elastic system, and natural frequency is a property of he system.A forced vibration takes place under the excitation of an external force (or externally applied oscillatory disturbance) which is usually a function of time, e. g.in unbalanced rotating parts, imperfections in manufacture of gears and drives. The frequency of forced vibration is that of the exciting or impressed force, i. e. the forcing frequency is an arbitrary quantity independent of the natural frequency of the system.Resonance Resonance describes the condition of maximum amplitude. It occurs when the frequency of an impressed force coincides with, or is near to a natural frequency of the system. In this critical condition, dangerously large amplitudes and stresses may occur in mechanical systems but, electrically, radio and television receivers are designed to respond to resonant frequencies. The calculation or estimation of natural frequencies is, therefore, of great importance in all types of vibrating and oscillating systems. When resonance occurs in rotating shafts and spindles, the speed of rotation is known as the critical speed. Hence, the prediction and correction or avoidance3 of a resonant condition in mechanisms is of vital importance since, in the absence of damping or other amplitude-limiting devices, resonance is the condition at which a system gives an infinite response to a finite excitation.Damping Damping is the dissipation of energy from a vibrating system, and thus prevents excessive response. It is observed that a natural vibration diminishes in amplitude with time and, hence, eventually ceases owing to some restraining or damping influence. Thus if a vibration is to be sustained, the energy dissipated by damping must be replaced from an external source.The dissipation is related in some way to the relative motion between the components or elements of the system, and is caused by frictional resistance of some sort, e.g. in structures, internal friction in material, and external friction caused by air or fluid resistance called “viscous” damping if the drag force is assumed proportional to the relative velocity between moving parts. One device assumed to give viscous damping is the “dashpot” which is a loosely fitting piston in a cylinder so that fluid can flow from one side of the piston to the other through the annular clearance space.A dashpot cannot store energy but can only dissipate it.Basic Machining Operations and Machine ToolsBasic Machining OperationsMachine tools have evolved from the early foot-powered lathes of the Egyptians and John Wilkinson’s boring mill. They are designed to provide rigid support for both the workpiece and the cutting tool and can precisely control their relative positions and the velocity of the tool with respect to the workpiece. Basically, in metal cutting, a sharpened wedge-shaped tool removes a rather narrow strip of metal from the surface of a ductile workpiece in the form of a severely deformed chip. The chip is a waste product that is comsiderably shorter than the workpiece from which it came but woth a corresponding increase in thickness of the uncut chip. The geometrical shape of the machine surface depedns on the shape of the tool and its path during the machinig operation.Most machining operations produce parts of differing geometry. If a rough cylindrical workpiece revolves about a central axis and the tool penetrates beneath its surface and travels parallel to the center of rotation, a surface of revolution is producedand the operation is called turning. If a hollow tube is machined on the inside in a similar manner, the operation is called boring. Producing an external conical surface of uniformly varying diameter is called taper turning. If the tool point travels in a path of varying radius,a contoured surface like that of a bowling pin a can be produced; or, if the piece is short enough and the support is sufficiently rigid, a contoured surface could be produced by feeding a shaped tool normal to the axis of rotation. Short tapered or cylindrical surfaces could also be contour formed.Flat or plane surfaces are frequently required. The can be generated by adial turning or facing, in which the tool point moves normal to the axis of rotation. In other cases, it is more convenient to hold the workpiece steady and reciprocate the tool across it in a series of straight-line cuts with a crosswise feed increment before each cutting stroke. This operation is called planing and is carried out on a shaper. For larger pieces it is easier to keep the tool stationary and draw the workpiece under it as inplaning. The tool is fed at each reciprocation. Contoured surfaces can be produced by using shaped tools.Multiple-edged tools can also be used. Drilling uses a twin-edged fluted tool for holes with depths up to 5 10times the drill diameter. Whether the dril turns or the workpiece rotates, relative motion between the cutting edge and the workpiece is the important factor. In milling operations a rotary cutter with a number of cutting edges engages the workpiecem which moves slowly with respect to the cutter. Plane or contoured surfaces may be produced, depending on the geometry of the cutter and the type of feed. Horizontal or vertical axes of rotation ma be used, and the feed of the workpiece may be in any of the three coordinate directions.Basic Machine ToolsMachine tools are used to produce a part of a specified geometrical shape and precise size by removing metal from a ductile materila in the form of chips. The latter are a waste product and vary from long continuous ribbons of a ductile material such as steel, which are undesirable from a disposal point of view, to easily handled well-broken chips resulting from cast iron. Machine tools perform five basic metal-removal processes: turning, planing, drilling, milling, and frinding. All other metal-removal processes are modifications of these five basic processes. For example, boring is internal turning;reaming,tapping, and counterboring modify drilled holes and are related to drilling; hobbing and gear cutting are fundamentally milling operations; hack sawong and broaching are a form of planing and honing; lapping, superfinishing, polishing, and buffing are avariants of grinding or abrasive removal operations. Therefore, there are only four types of basic machine tools, which use cutting tools of specific controllable feometry: thes, 2.planers, 3.drilling machines, and ling machines. The frinding process forms chips, but the geometry of the barasive grain is uncontrollable.The amount and rate of material removed by the various machining processes may be large, as in heavy truning operations, or extremely small, as in lapping or superfinishing operations where only the high spots of a surface are removed.A machine tool performs three major functions: 1.it rigidly supports the workpiece orits holder and the cutting tool; 2. it provedes relative motion between the workpiece and the cutting tools; 3. it provides a range of feeds and speeds usually ranging from 4 to 32 choices in each case.Speed and Feeds in MachiningSpeeds feeds, and depth of cut are the three major variables for economical machining. Other variables are the work and tool materials, coolant and geometry of the cutting tool. The rate of metal removal and power required for machining depend upon these variables.The depth of cut, feed, and cutting speed are machine settings that must be established in any metal-cutting operation. They all affect the forces, the power, and the rate of metal removal. They can be defined by comparing them to the needle and record of a phonograph. The cutting speed is represented by the velocity of the record surface relative to the needle in the tone arm at any instant. Feed is represented by the advance the needle radially inward per revolution, or is the difference in position between two adjacent grooves.Turning on Lathe CentersThe basic operations performed on an engine lathe are illustrated in Fig. Those operations performed on extemal surfaces with a single point cutting tool are called turning. Except for drilling, reaming, and tapping, the operations on intermal surfaces are also performed by a single point cutting tool.All machining operations, including turning and boring, can be classified as roughing, finishing, or semi-finishing. The objective of a roughing ooperation is to remove the bulk of the material sa repidly and as efficiently as possible, while leaving a small amount of material on the work-piece for the finishing operation. Finishing operations are performed to btain the final size, shape, and surface finish on the workpiece. Sometimes a semi-finishing operation will precede the finishing operation to leave a small predetermined and uniform amount of stoxd on the work-piece to be removed by the finishing operation.Generally, longer workpieces are turned while supported on one or two lathe centers. Cone shaped holes, called center holes, which fit the lathe centers are drilled in the ends of the workpiece-usually along the axis of the cylindrical part. The end of the workpiece adjacent to the tailstock is always supported by a tailstock center, while the end near the headstock may be supported by a headstock cener or held in a chuck. The headstock end of the workpiece may be held in a four-jar chuck, or in a collet type chuck. This method holds the workpiece firmly and transfers the power to the workpiece smoothly; the additional support to the workpiece priovided by the chuck lessens the tendency for chatter to occur when cutting. Precise results can be obtained with this method if care is taken to hold the workpiece accurately in the chuck.Very precise results can be obtained by supporting the workpiece between two centers.A lathe dog is clamped to the workpiece; together they are driven by a driver p;ate mounted on the spindle nose. One end of the workpiece is machined; then the workpiece can be turned around in the lathe to machine the other end. The center holes in the workpiece serve as precise locating surfaces as well as bearing surfaces to carry the weight of the workpiece and to resist the xutting forces. After the workpiece has been removed from the lathe for any reason, the center holes will accurately align the workpiece back in the lathe or in another lathe,or in a cylindrical grinding machine. The workpiece must never be held at the headstock end by both a chuck and a lathe center. While at first thought this seems like a quick method of aligning the workpiece in the chuck, this must not be done because it is not possible to press evenly with the jaws against the workpiece while it is also supported by the center. The alignment provided by the center will not be maintained and the pressure of the jaws may damage the center hole, the lathe center,and prehaps even the lathe spindle. Compensatng or floating jaw chucks used almost exclusively on high production work provice an exception to the statements made above. These chucks are really work drivers and cannot be used for the same purpose as ordinary three or four=jaw chucks. While very large diameter workpieces are sometimes mounted on two centers, they are preferably held at the headstock end by faceplate jaes to obtain the smooth power transmission; moreover, large lathe dogs that are adequate to transmit the power notgenerally available, although they can be maed as a special. Faceplate jaws are like chuck jaws except that thet are mounted on a faceplate, which has less overhang from the spindle bearings than a large chuck would have.BoringThe boring operation is generally performed in two steps; namely, rough boring and finish boring. The objective of the rough-boring operation is to remove the excess metal rapidly and efficiently, and the objective of the finish-boring operation is to obtain the desired size, surface finish, and location of the hole. The size of the hole is obtained by using the trial-cut procedure. The diameter of the hole can be measured with inside calipers and outside micrometer calipers. Basic Measuring Insteruments, or inside micrometer calipers can be used to measure the diameter directly.Cored holes and drilled holes are sometimes eccentric wwith respect to the rotation of the lathe. When the boring tool enters the work, the boring bar will take a deeper cut on one side of the hole than on the other, and will deflect more when taking this deeper cut,with the result that the bored hole will not be concentric with the rotation of the work. This effect is corrected by taking several cuts through the hole using a shallow depth of cut. Each succeeding shallow cut causes the resulting hole to be more concentric than it was with the previous cut. Before the final, finish cut is taken, the hole should be concentric with the rotation of the work in order to make certain that the finished hole will be accurately located.Shoulders, grooves, contours, tapers, and threads are bored inside of holes. Internal grooves are cut using a tool that is similar to an external grooving tool. The procedure for boring internal shoulders is very similar to the procedure for turning rge shoulders are faced with the boring tool positioned with the nose leading, and using the cross slide to feed the tool. Internal contours can be machined using a tracing attachment on a lathe. The tracing attachment is mounted on the cross slide and the stylus follows the outline of the master profile plate. This causes the cutting tool to move in a path corresponding to the profile of the master profile plate.Thus, the profile on the master profile plate is reproduced inside the bore. The master profile plate is accurately mounted on a special slide which can be precisely adjusted in two dirctions, in two directionsm, in order to align the cutting tool in the correct relationship to the work. This lathe has a cam-lick type of spindle nose which permits it to take a cut when rotating in either direction. Normal turning cuts are taken with the spindle rotating counterclockwise. Thie boring cut is taken with the spindle revolving in a clockwise direction, or “backwards”. This permits the boring cut to be taken on the “back side” of the bore which is easier to see from the operator’sposition in front of the lathe. This should not be done on lathes having a threaded spindle nose because the cutting force will tend to unscrew the chuck.中文翻译振动的定义和术语振动所有的物质---固体，液体和气体-----都能够振动，例如，在喷气发动机尾部导管中产生的气体振动会发出令人讨厌的噪声，而且有时还会使金属产生疲劳裂缝。

振动筛在参数化运行中的一个简单的动力学模型外文文献翻译、中英文翻译

附录一外文翻译我们考虑了振动筛在参数化运行中的一个简单的动力学模型。

共振(PR)模式该模型在设计和设置该模型的过程中得到了应用。

屏幕在LPMC。

基于PR的屏幕与传统类型的屏幕相比更好。

机器，在那里横向振动是直接激发的。

它的特点是更大振幅的值和在相当宽的范围内对阻尼不敏感。

模型表示由线性弹性连接的两个质量相等的初始应变系统。

绳子。

自平衡的、纵向的、调和的力作用于群众.在一定范围内这会导致弦的横向有限振幅振荡.问题是-Lem被简化为由几何耦合的两个常微分方程组。

非线性横向和纵向振动的阻尼都被考虑到交流中。

数一数。

分析研究了该质量弦系统的自由振动和强迫振动。

数字。

自由的纵横模之间的能量交换证明了振荡。

得到了强迫振荡的精确解析解，联轴器起着稳定器的作用。

在更一般的情况下，谐波肛门-在使用中忽略了高次谐波。

的所有参数的显式表达式。

确定了稳态非线性振动。

这些域被发现在分析的地方-得到的稳定振荡区是稳定的。

在频率范围内，存在稳定的振荡，得到的振幅之间存在完全的对应关系。

从分析和数值上。

基于解析和数值模拟的图解介绍。

关键词：振动筛以参数共振方式工作；PLE二自由度系统；幅频特性；非线性动力学方程；解析解；数值模拟。

1 介绍本文研究了基于参数共振的系统。

振动筛，图1：振动筛及其最简单的模型。

在屏幕照片：振动器(1)，底座(2)，固定筛子的横梁(3)，振动筛盖(4)，侧边。

弹簧(5)和筛子(6)(它主要在盖子下面)。

在模型中：终端质量可以在相反的水平方向上同步移动，而字符串可以横向振荡。

这两种振动模式是耦合的，因为拉力依赖于质量的纵向位移和弦的横向位移(后者是非线性的)。

创建这样一台机器的想法是在2007年讨论现有的屏幕类型。

2009年，该专利的激励方法屏幕和相应的结构的后者[1]。

当时，非线性动力学对这种机器进行了数值模拟，建立了第一个基于PR的屏幕。

在Loginov 和合作伙伴矿业公司（基辅，乌克兰）。

基于PR的屏幕比较对传统的这类机器很有好处，在这种机器中，横向振荡是直接兴奋。

1、下载文档前请自行甄别文档内容的完整性，平台不提供额外的编辑、内容补充、找答案等附加服务。
2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
3、如文档侵犯您的权益，请联系客服反馈,我们会尽快为您处理(人工客服工作时间：9:00-18:30)。

毕业设计--圆振动筛设计的外文翻译辽宁科技大学本科生毕业设计第1页Screening Vibrating screensPrinciples --Vibrating screens save space and weight and operate on little power because the screening surface may be actuated by vibrating, gyrating or pulsatingmovement of small amplitude, but at frequencies that normally exceed 3,000/min.Selection of Proper Vibration Sereen --Be sure the screen supplier knows all details ofthe application. The centrifugal force factor, or combination of frequency of vibration(speed) and amplitude (throw), may affect performance of anyvibrating screen. Also,a correct combination of slope and direction of mechanism rotationis vital forinclined screens. Usually, the larger the opening, the greater the amplitude needed fora screen.If the throw is too small, the material may clog or wedge in the openings. Increasingthe throw beyond what is required to prevent blinding or plugging does notnecessarily increase the life of the bearings and reduce screening efficiency.Increased rate of travel permits more tonnage to be passed over the screen per unit oftime. For a given tonnage, a faster rate of travel results in a thinner bed of materialand high screening efficiency.Maximum slope is reached when the material travels too fast for the fines to penetratethe ribbon of material and reach the apertures in the screen cloth. At this point anexcessive amount of fine material passes over the screen with the oversize, resultingin poor efficiency.When an existing screen is to be used for an application other than that for which itwas originally intended, check with the Supplier to see if any of the operatingcharacteristics need modification and if the the screen is structurally suitable for thenew application.The operator can get the correct vibrating screen by providing the supplier with thefollowing information:, Maximum tons per hour to be screened, including any circulating load or anysurges in the feed rate., A complete size consist or sieve analysis of the material or, if available, anestimated analysis., Type of material and weight per cubic foot in broken state., Separations desired on each deck., Surface moisture carried by the material if screening is to be dry or amount ofwater with feed if wet., Special operating requirements or conditions such as temperature, abrasiveness, corrosiveness or other physical characteristics of the feed,辽宁科技大学本科生毕业设计第2页efficiency or product requirements which determine selection of screeningsurface, or installation problems which affect screen size selection or capacity.General Types --Vibrating screens may be divided into two main classes: mechanically-vibrated and electrially-vibrated. The former can be subdivided into classes based on how the vibration is produced--by eccentrics; by unbalanced weight; by cams or bumpers. They can also be subdivided as inclined and horizontal. Sizes --Vibrating screens aremade in standard sizes of from 12 in. to 10 ft wide and from 2 1/2 ft to 28 ft long. Common practice dictates that the length of the screen should be 2.5 times the width for dry screening. For wet screening, wider and shorter screen is best. Screens for scalping ahead of primary crushers, operate at a slope of from 12 degrees to 18 degrees and have openings as large as 11-in. square. The eccentric throw for openings from 5 to 11 in. is usually 1/2 in.; for openings from 3 to 5 in. about 3/8 in.; and for smaller openings 1/4 in. The screening surface consists of a heavy cast desk, perforated steel with or without skid bars welded between the holes, rod deck, etc.The mechanical shaking screen comprises a rectangular frame, with perforated steel or wire cloth screening medium. It is usually inclined and suspended on loose rods or cables. These screens now are used mainly for special tasks of coarse screening, having given way to vibrating screens.Electrically-Heated Screens --Electrically heated screen cloth decks have affordedbetter screening and less dust. Modern or updated screening operations, now handling clays, limestone, potash, salts, phosphates and various hydroscopic materials, report minimum dust loss when equipped with heated screens. The controlling factor in this improvement is the electrically-heated screen doth deck. Any vibratory screen with fine opening (less than 1/2 in.) can be equipped with low volt-age-high amperage resistance heating.The principle of electric heating is based on the fact that small diameter wire of screen cloth (especially stainless steel) serves as a conductor, but offers resistance to a high-amperage current. This resistance causes heating of the wire when powerful transformer and specially designed bus bars connected to screen doth decks push up to 6,000 amps current into a circuit. The current is safe and shock-proof because voltage is low, ranging from approximately 1 1/2 to 16 volts. Workers can do their jobs around electrically-heated screens without special precautions.Heated screens are effective in preventing moisture content of material from causing buildup and blinding. The screen wire is kept at 100 degrees to 130 degrees F depending on character and tonnage of the material processed. This temperature is not high enough to weaken the wire cloth or screen structure, nor does it suffice to drive off moisture held in material. The warm wire stays dry, breaking the surface tension that otherwise would bind damp material to cold, damp metal. This differential or辽宁科技大学本科生毕业设计第3页warm, dry screen wire versus cold, damp material can be maintained economically through transformer control settings.With every opening in the heated screen mesh protected against blinding, there is no guesswork about what size particle will be delivered. A uniform, unvarying quality to meet tough specificationscomes through day after day, no matter what the weather. (High humidity makes trouble with unheated screens.) Plants operating heated screens will have no trouble with excessive amounts of fine, dusty material that formerly sifted through reduced meshes on clogged screens.Service life of screen cloth is greatly increased when electric heating ends the punishment of old-fashioned cleaning methods, such as rough pounding or brushing. Blowtorch flames put too much heat in one spot and bouncing chains added to wear and tear. But, screens kept clean and open with electric heating reportedly are seldom mistreated and last up to eight times as long. Heated decks end the threat of pile ups and strains that can break the mesh.Economical operation of electric heating for screens requires one transformer for installations of up to three panels of screen cloth (maximum area 4- x 12-ft). Two transformers are used on longer decks. Any deck (top, center or bottom) can be heated. Electric heating is most desirable of all where a screen surface is hard to get at. Changing heated screens does not involve more unbolting than needed for ordinary screens.In specifying screens to deliver a uniform particle through heated mesh, the first thing to consider is weight per square foot of the wire cloth needed to set up appropriate resistance. Most calculations are based on square openings. Slotted openings must be identified as to width of clear opening, diameter of wire and number of wires per inch before weight per square foot can be found in any screen clothmanufacturer's catalog. Having determined the usable weight per square foot of screen cloth, the next step is to select the size of clear opening needed, making no allowance for reduction in this size as formerly was the case when material stuck to the wires. Heated wireswill maintain the clear opening at all times, making it possible to screen finer without blinding.From a wire catalog, select a mesh weighing no more per square foot (can weigh less) than determined using the method above with the clear opening characteristics desired. This often turns out to be a more efficient screen because the wire diameter will be smaller and the percentage of the open area will be greater.For example, where a 1/8-in. clear opening was desired (but often blinded) on unheated screens, the wire diameter was 0.63 and the open area was 44 percent. The cloth weighed 1.43 lb/ft.2. For a heated 3- x 12-ft screen, the weight must not exceed辽宁科技大学本科生毕业设计第5页21.1 lb/ft. Two options were found in cloth with 1/8-in. clear opening: wire2diameter .054 weighing 1.09 lb/ft providing 48.8 percent open area; and wire2diameter .047 weighing 0.85 lb/ft with a 52.8 percent open area. Load conditions may make fine diameters of carbon steel wire inadequate. In suchcases, stainless steel wire of larger diameter with greater load-carrying capacity willhave the necessary resistance for good heating.Lighter wire with more open area yields higher tonnage and heated mesh stays open100 percent. Two screen cloths connected in a series may be of different mesh sizes orclear openings, as long as they both weigh the same per ft2 and donot exceed theweight allowed for that particular size of screen.With heated screens, major savings in pollution control are possible. Also moisturecontent of material is reportedly increased in a range of 5 to 8 percent. This moistureis added during or after crushing-grinding operations and holds down dust duringtransfer of material and passage over heated screens. Warm wire handles 5 to 8percent moisture in stride. The cost of heating equipment and mist spraying reportedlyis less than the cost of having bag towers and precipitators.辽宁科技大学本科生毕业设计第5页振动筛的选择振动筛的选择原则：选择振动筛的原则是所选择的振动筛要节省空间、重量并且驱动的功率要小，因为筛选表面可以驱动并且发生振动。