机械毕业设计英文外文翻译63超高速行星齿轮组合中内部齿轮的有限元分析

Gears are vital factors in machinery. One of the first mechanism invented using gears was the clocks. In fact, a clock is little more than a train of study and research have been made on gears in recent years because of their wide use under exacting conditions. They have to transmit heavier loads and run at higher speeds than ever before. The engineers and the machinists all consider gearing the prime elementin nearly all classes of machinery.齿轮在机械中占有极为重要的作用。

第一个利用齿轮做成的机械装置确实是钟表，事实上，它只只是是用了一系列的齿轮。

关于它能够在严格的条件下的普遍利用，在齿轮上做了大量的学习和研究。

相较过去，它们此刻必需在更高的速度下传递更重的负荷。

工程师和机械操纵工人都以为齿轮在几乎所有的机械的零件中占有首要的因素。

1. Spur gearsSpur gears are used to transmit power and rotary motion between parallel shafts. The teeth are cut parallel to the axis of the shaft on which the gears are mounted. The smaller of two gears in mesh is called the pinion and the larger is customarily Designated as the gear. In most applications, the pinion is the driving element whereas the gear is the driven element.1.直齿圆柱齿轮直齿圆柱齿轮用于平行轴之间传递力和回转运动，轮齿被切制成与安装齿轮的轴之轴线相平行。

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

机械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 because 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 that pecking and running at a high spindle speed increase the d rill’s effectiveness.The requirements for how fast microtools should rotate depend on the type of CNCmachines a shop uses and the tool diameter, with higher speeds needed as the diameter decreases. (Note: The equation for cutting speed is sfm = tool diameter × 0.26 × spindle speed.)Although relatively low, 5,000 rpm has been used successfully by Burton’s customers. “We recommend that our customers find the highest rpm at the lowest possible vibration—the sweet spot,” he said.In addition to minimizing vibration, a constant and adequate chip load is required to penetrate the workpiece while exerting low cutting forces and to allow the rake to remove the appropriate amount of material. If the drill takes too light of a chip load, the rake face wears quickly, becoming negative, and tool life suffers. This approach is often tempting when drilling with delicate tools.“If the customer decides he wants to baby the tool, he takes a lighter chip load,” Burton said, “and, typically, the cutting edge wears much quicker and creates a radius where the land of that radius is wider than the chip being cut. He ends up using it as a grinding tool, trying to bump material away.” For tools larger than 0.001", Burton considers a chip load under 0.0001" to be “babying.” If the drill doesn’t snap, premature wear can result in abysmal tool life.Too much runout can also be destructive, but how much is debatable. Burton pointed out that Performance purposely designed a machine to have 0.0003" TIR to conduct in-house, worst-case milling scenarios, adding that the company is still able to mill a 0.004"-wide slot “day in and day out.”He added: “You would think with 0.0003" runout and a chip load a third that, say, 0.0001" to 0.00015", the tool would break immediately because one flute would be taking the entire load and then the back end of the flute would be rubbing.When drilling, he indicated that up to 0.0003" TIR should be acceptable because once the drill is inside the hole, the cutting edges on the end of the drill continue cutting while the noncutting lands on the OD guide the tool in the same direction. Minimizing run out becomes more critical as the depth-to-diameter ratio increases. This is because the flutes are not able to absorb as much deflection as they become more engaged in the workpiece. Ultimately, too much runout causes the tool shank to orbit around the tool’s center while the tool tip is held steady, creating a stress point where the tool will eventually break.Taking a PlungeAlthough standard micro drills aren’t generally available below 0.002", microendmills that can be used to “plunge” a hole are. “When people want to drillsmaller than that, they use our endmills and are pretty successful,” Burton said. However, the holes can’t be very deep because the tools don’t have long aspect, or depth-to-diameter, ratios. Therefore, a 0.001"-dia. endmill might be able to only make a hole up to 0.020" deep whereas a drill of the same size can go deeper because it’s designed to place the load on its tip when drilling. This transfers the pressure into the shank, which absorbs it.Performance offers endmills as small as 5 microns (0.0002") but isn’t keen on increasing that line’s sales. “When people try to buy them, I very seriously try to talk them out of it bec ause we don’t like making them,” Burton said. Part of the problem with tools that small is the carbide grains not only need to be submicron in size but the size also needs to be consistent, in part because such a tool is comprised of fewer grains. “The 5-m icron endmill probably has 10 grains holding the core together,” Burton noted.He added that he has seen carbide powder containing 0.2-micron grains, which is about half the size of what’s commercially available, but it also contained grains measuring 0.5 and 0.6 microns. “It just doesn’t help to have small grains if they’re not uniform.”MicrovaporizationElectrical discharge machining using a sinker EDM is another micro-holemaking option. Unlike , which create small holes for threading wire through the workpiece when wire EDMing, EDMs for producing microholes are considerably more sophisticated, accurate and, of course, expensive.For producing deep microholes, a tube is applied as the electrode. For EDMing smaller but shallower holes, a solid electrode wire, or rod, is needed. “We try to use tubes as much as possible,” said Jeff Kiszonas, EDM product manager for Makino Inc., Auburn Hills, Mich. “But at some point, nobody can make a tube below a certain diameter.” He added that some suppliers offer tubes down to 0.003" in diameter for making holes as small as 0.0038". The tube’s flushing hole enables creating a hole with a high depth-to-diameter ratio and helps to evacuate debris from the bottom of the hole during machining.One such sinker EDM for produc ing holes as small as 0.00044" (11μm) is Makino’s Edge2 sinker EDM with fine-hole option. In Japan, the machine tool builder recently produced eight such holes in 2 minutes and 40 seconds through 0.0010"-thick tungsten carbide at the hole locations. The electrode was a silver-tungsten rod 0.00020" smaller than the hole being produced, to account for spark activity in the gap.When producing holes of that size, the rod, while rotating, is dressed with acharged 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 the 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, Jorgensen 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 a ppropriate “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 tec hnologies. 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 range 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 another 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 micromachining 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。

齿轮基本术语中英文对照齿轮Toothed gear；Gear齿轮副Gear pair平行轴齿轮副Gear pair with parallel axes相交轴齿轮副Gear pair with intersecting axes 齿轮系Train of gears行星齿轮系Planetary gear train齿轮传动Gear drive；Gear transmission配对齿轮Mating gears小齿轮Pinion大齿轮Wheel；Gear主动齿轮Driving gear从动齿轮Driven gear行星齿轮Planet gear行星架Planet carrier太阳轮Sun gear内齿圈Ring gear；Annulus gear外齿轮External gear内齿轮Internal gear中心距Centre distance轴交角Shaft angle连心线Line of centres减速齿轮副Speed reducing gear pair增速齿轮副Speed increasing gear pair齿数比Gear ratio传动比Transmission ratio轴平面Axial plane基准平面Datum plane节平面Pitch plane端平面Transverse plane法平面Normal plane分度曲面Reference surface节曲面Pitch surface齿顶曲面Tip surface齿根曲面Root surface基本齿廓Basic tooth profile基本齿条Basic rack产形齿条Counterpart rack产形齿轮Generating gear of a gear产形齿面Generating flank基准线Datum line轮齿Gear teeth；Tooth齿槽Tooth space右旋齿Right-hand teeth左旋齿Left—hand teeth变位齿轮Gears with addendum modification;X-gears高度变位圆柱齿轮副X-gear pair with reference centre distance 角度变位圆柱齿轮副X-gear pair with modified centre distance 高度变位锥齿轮副X—gear pair without shaft angle modification 角度变位圆柱齿轮副X-gear pair with shaft angle modification变位系数Modification coefficient变位量Addendum modification径向变位系数Addendum modification coefficient中心距变位系数Centre distance modification coefficient圆柱齿轮Cylindrical gear顶圆Tip circle根圆Root circle齿距Pitch齿距角Angular pitch公法线长度Base tangent length分度圆直径Reference diameter节圆直径Pitch diameter基圆直径Base diameter顶圆直径Tip diameter根圆直径Root diameter齿根圆角半径Fillet radius齿高Tooth depth工作高度Working depth齿顶高Addendum齿根高Dedendum弦齿高Chordal height固定弦齿高Constant chord height齿宽Facewidth有效齿宽Effective facewidth端面齿厚Transverse tooth thickness法向齿厚Normal tooth thickness端面基圆齿厚Transverse base thickness法向基圆齿厚Normal base thickness端面弦齿厚Transverse chordal tooth thickness固定弦齿厚Constant chord端面齿顶厚Crest width法向齿顶厚Normal crest width端面齿槽宽Transverse spacewidth法向齿槽宽Normal spacewidth齿厚半角Tooth thickness half angle槽宽半角Spacewidth half angle压力角Pressure angle齿形角Nominal pressure angle圆弧圆柱蜗杆Arc—contact worm；hollow flank worm；ZC—worm直廓环面蜗杆Enveloping worm with straight line grneratrix;TA worm平面蜗杆Planar worm wheel；P-worm wheel平面包络环面蜗杆Planar double enveloping worm；TP—worm平面二次包络蜗杆Planar double—enveloping worm wheel;TP-worm wheel锥面包络环面蜗杆Toroid enveloping worm wheel；TK—worm wheel渐开线包络环面蜗杆Toroid enveloping worm hich involute holicoid generatrix；TI-worm锥蜗杆Spiroid锥蜗轮Spiroid gear锥蜗杆副Spiroid gear pair中平面Mid-plane长幅内摆线Prolate hypocycloid短幅内摆线Curtate hypocycloid渐开线Involute;Involute to a circle延伸渐开线Prolate involute缩短渐开线Curtate involute球面渐开线Spherical involute渐开螺旋面Involute helicoid阿基米德螺旋面Screw helicoid球面渐开螺旋面Spherical involute helicoid圆环面Toroid圆环面的母圈Generant of the toroit圆环面的中性圈Middle circle of the toroid圆环面的中间平面Middle—plane of the toroid圆环面的内圈Inner circle of the toroid啮合干涉Meshing interference切齿干涉Cutter interference齿廓修型Profile modification；Profile correction修缘Tip relief修根Root relief齿向修形Axial modification；Longitudinal correction齿端修薄End relief鼓形修整Crowning鼓形齿Crowned teeth挖根Undercut瞬时轴Instantaneous axis瞬时接触点Point of contact瞬时接触线Line of contact端面啮合线Transverse path of contact啮合曲面Surface of action啮合平面Plane of action啮合区域Zone of action总作用弧Total arc of transmission端面作用弧Transverse arc of transmission纵向作用弧Overlap arc总作用角Total angle of transmission端面作用角Transverse angle of transmission 纵向作用角Overlap angle总重合度Total contact ratio端面重合度Transverse ratio纵向重合度Overlap ratio标准齿轮Standard gears非变位齿轮X—gero gear标准中心距Referencr centre distance名义中心距Nominal centre distance分度圆柱面Reference cylinder节圆柱面Pitch cylinder基圆柱面Basic cylinder齿顶圆柱面Tip cylinder齿根圆柱面Root cylinder节点Pitch point节线Pitch line分度圆Reference circle节圆Pitch circle基圆Basic circle定位面Locating face外锥距Outer cone distance内锥距Inner cone distance中点锥距Mean cone distance背锥距Back cone distance安装距Locating distance轮冠距Tip distance；crown to back冠顶距Apex to crown偏置距Offset齿线偏移量Offset of tooth trace分锥角Reference cone angle节锥角Pitch cone angle顶锥角Tip angle根锥角Root angle背锥角Back cone angle齿顶角Addendum angel齿根角Dedendum angle任意点压力角Pressure angle at a point任意点螺旋角Spiral angle at a point中点螺旋角Mean spiral angle大端螺旋角Outer spiral angle小端螺旋角Inner spiral angle蜗杆Worm蜗轮Worm wheel蜗杆副Worm gear pair圆柱蜗杆Cylindrical worm圆柱蜗杆副Cylindrical worm pair环面蜗杆Enveloping worm环面蜗杆副Enveloping worm pair阿基米德蜗杆Straight sided axial worm；ZA—worm渐开线蜗杆Involute helicoid worm；ZI—worm法向直廓蜗杆Straight sided normal worm；ZN—worm锥面包络圆柱蜗杆Milled helicoid worm；ZK—worm椭圆齿轮Elliptical gear非圆齿轮副Non-circular gear pair圆柱针轮副Cylindsical lantern pinion and wheel针轮Cylindsical tan tein gear ；pin—wheel谐波齿轮副Harmoric gear drive波发生器Wave generator柔性齿轮Flexspine刚性齿轮Circular spline非圆齿轮Non—circular gear分度圆环面Reference tosoidinvolute spline data：渐开线花键参数flat root side fit ：平齿根齿侧定心三维｜cad|机械｜汽车技术｜catia|pro/e|ug｜nventor|solidedge|soli dworks｜caxa＃u5 f9 E4 {6 p1 `, V；B2 ｜/ ^pith（应为pitch）：径节14/32number of teeth：齿数195 d，b. w( @6 ｝# f9pressure angle ：压力角30base cicle dia (ref) ：基圆直径( K. M H' r！J$ \* S$ ］2 _cicular space width:分度圆齿槽宽min effective:最小作用齿槽宽0。

(文档含英文原文和中文翻译)中英文资料对照外文翻译Machine Parts (I)GearsGears are direct contact bodies, operating in pairs, that transmit motion and force from one rotating shaft to another or from a shaft to a slide (rack), by means of successively engaging projections called teeth.Tooth profiles. The contacting surfaces of gear teeth must be aligned in such a way that the drive is positive; i.e., the load transmitted must not depend on frictional contact. As shown in the treatment of direct contact bodies, this requires that thecommon normal to the surfaces not to pass through the pivotal axis of either the driver or the follower.As it is known as direct contact bodies, cycloidal and involute profiles profiles provide both a positive drive and a uniform velocity ratio;i.e., conjugate action.Basic relations. The smaller of a gear pair is called the pinion and the larger is the gear. When the pinion is on the driving shaft the pair is called the pinion and the larger is the gear. When the pinion is on the driving shaft the pair acts as a speed reducer; When the gear drives, the pair is a speed incrreaser. Gears are more frequently used to reduce speed than to increase it.If a gear having N teeth rotates at n revolutions per minute, the product N*n has the dimension “teeth per minute”. This product must be the same for both members of a mating pair if each tooth acquires a partner from the mating gear as it passes through the region of tooth engagement.For conjugate gears of all types, the gear ratio and the speed ratio are both given by the ratio of the number of teeth on the gear to the number of teeth on the pinion. If a gear has 100 teeth and a mating pinion has 20, the ratio is 100/20=5. Thus the pinion rotates five times as fast as the gear, regardless of the gear. Their point of tangency is called the pitch point, and since it lies on the line of centers, it is the only point at which the profiles have pure roling contact. Gears on nonparallel, non-intersecting shafts also have pitch circles, but the rolling-pitch –circle concept is not valid.Gear types are determined largely by the disposition of the shafts; in addition, certain types are better suited than others for large speed changes. This means that if a specific disposition of the shafts is required, the type of gear will more or less be fixed. On the other hand, if a required speed change demands a certain type, the shaft positions will also be fixed.Spur gears and helical gears. A gear having tooth elements that are straight and parallel to its axis is known as a spur gear. A spur pair can be used to connect parallel shafts only.If an involute spur pinion were made of rubber and twisted uniformly so that the ends rotated about the axis relative to one another, the elements of the teeth, initially straight and parallel to the axis, would become helices. The pinion then in effect would become a helical gear.Worm and bevel gears. In order to achieve line contact and improve the load carrying capacity of the crossed axis helical gears, the gear can be made to curvepartially around the pinion, in somewhat the same way that a nut envelops a screw. The result would be a cylindrical worm and gear. Worms are also made in the shape of an hourglass, instead of cylindrical, so that they partially envelop the gear. This results in a further increase in load-carrying capacity.Worm gears provide the simplest means of obtaining large ratios in a single pair. They are usually less efficient than parallel-shaft gears, however, because of an additional sliding movement along the teeth.V-beltThe rayon and rubber V-belt are widely used for power transmission. Such belts are made in two series: the standard V-belt and the high capacity V-belt. The belts can be used with short center distances and are made endless so that difficulty with splicing devices is avoided.First, cost is low, and power output may be increased by operating several belts side by side. All belts in the drive should stretch at the same rate in order to keep the load equally divided among them. When one of the belts breaks, the group must usually be replaced. The drive may be inclined at any angle with tight side either top or bottom. Since belts can operate on relatively small pulleys, large reductions of speed in a single drive are possible.Second，the included angle for the belt groove is usually from 34°to 38°.The wedging action of the belt in the groove gives a large increase in the tractive force developed by the belt.Third，pulley may be made of cast iron, sheet steel, or die-cast metal. Sufficient clearance must be provided at the bottom of the groove to prevent the belt from bottoming as it becomes narrower from wear. Sometimes the larger pulley is not grooved when it is possible to develop the required tractive force by running on the inner surface of the belt. The cost of cutting the grooves is thereby eliminated. Pulleys are on the market that permit an adjustment in the width of the groove. The effective pitch diameter of the pulley is thus varied, and moderate changes in the speed ratio can be secured.Chain DrivesThe first chain-driven or “safety” bicycle appeared in 1874, and chains were used for driving the rear wheels on early automobiles. Today, as the result of modern design and production methods, chain drives that are much superior to their prototypes are available, and these have contributed greatly to thedevelopment of efficient agricultural machinery, well-drilling equipment, and mining and construction machinery. Since about 1930 chain drives have become increasingly popular, especially for power saws, motorcycle, and escalators etc.There are at least six types of power-transmission chains; three of these will be covered in this article, namely the roller chain, the inverted tooth, or silent chain, and the bead chain. The essential elements in a roller-chain drive are a chain with side plates, pins, bushings (sleeves), and rollers, and two or more sprocket wheels with teeth that look like gear teeth. Roller chains are assembled from pin links and roller links. A pin link consists of two side plates connected by two pins inserted into holes in the side plates. The pins fit tightly into the holes, forming what is known as a press fit. A roller link consists of two side plates connected by two press-fitted bushings, on which two hardened steel rollers are free to rotate. When assembled, the pins are a free fit in the bushings and rotate slightly, relative to the bushings when the chain goes on and leaves a sprocket.Standard roller chains are available in single strands or in multiple strands, In the latter type, two or more chains are joined by common pins that keep the rollers in the separate strands in proper alignment. The speed ratio for a single drive should be limited to about 10∶1; the preferred shaft center distance is from 30 to 35 times the distance between the rollers and chain speeds greater than about 2500 feet (800 meters) per minute are not recommended. Where several parallel shafts are to be driven without slip from a single shaft, roller chains are particularly well suited.An inverted tooth, or silent chain is essentially an assemblage of gear racks, each with two teeth, pivotally connected to form a closed chain with the teeth on the inside, and meshing with conjugate teeth on the sprocket wheels. The links are pin-connected flat steel plates usually having straight-sided teeth with an included angle of 60 degrees. As many links are necessary to transmit the power and are connected side by side. Compared with roller-chain drives, silent-chain drives are quieter, operate successfully at higher speeds, and can transmit more load for the same width. Some automobiles have silent-chain camshaft drives.Bead chains provide an inexpensive and versatile means for connecting parallel or nonparallel shafts when the speed and power transmitted are low. The sprocket wheels contain hemispherical or conical recesses into which the beads fit. The chains look like key chains and are available in plain carbon and stainless steel and also in the form of solid plastic beads molded on a cord. Bead chains are used oncomputers, air conditioners, television tuners, and Venetian blinds. The sprockets may be steel, die-cast zinc or aluminum, or molded nylon.Machine Parts (II)FastenerFasteners are devices which permit one part to be joined to a second part and, hence, they are involved in almost all designs.There are three main classifications of fasteners, which are described as follows：(1) Removable. This type permits the parts to be readily disconnected without damaging the fastener. An example is the ordinary nut-and-bolt fastener.(2) Semi permanent. For this type, the parts can be disconnected, but some damage usually occurs to the fastener. One such example is a cotter pin.(3) Permanent. When this type of fastener is used, it is intended that the parts will never be disassembled. Examples are riveted joints and welded joints.The importance of fasteners can be realized when referring to any complex product. In the case of the automobile, there are literally thousands of parts which are fastened together to produce the total product. The failure or loosening of a single fastener could result in a simple nuisance such as a door rattle or in a serious situation such as a wheel coming off. Such possibilities must be taken into account in the selection of the type of fastener for the specific application.Nuts, bolts, and screws are undoubtedly the most common means of joining materials. Since they are so widely used, it is essential that these fasteners attain maximum effectiveness at the lowest possible cost. Bolts are, in reality, carefully engineered products with a practically infinite use over a wide range of services.An ordinary nut loosens when the forces of vibration overcome those of friction. In a nut and lock washer combination, the lock washer supplies an independent locking feature preventing the nut from loosening. The lock washer is useful only when the bolt might loosen because of a relative change between the length of the bolt and the parts assembled by it. This change in the length of the bolt can be caused by a number of factors-creep in the bolt, loss of resilience, difference in thermal expansion between the bolt and the bolted members, or wear. In the above static cases, the expanding lock washer holds the nut under axial load and keeps the assembly tight. When relative changes are caused by vibration forces, the lock washer is not nearly as effective.Rivets are permanent fasteners. They depend on deformation of their structure for their holding action. Rivets are usually stronger than the thread-type fastener and are more economical on a first-cost basis. Rivets are driven either hot or cold,depending upon the mechanical properties of the rivet material. Aluminum rivets, for instance, are cold-driven, since cold working improves the strength of aluminum. Most large rivets are hot-driven, however.ShaftVirtually all machines contain shafts. The most common shape for shafts is circular and the cross section can be either solid or hollow (hollow shafts can result in weight savings).Shafts are mounted in bearings and transmit power through such devices as gears, pulleys, cams and clutches. These devices introduce forces which attempt to bend the shaft; hence, the shaft must be rigid enough to prevent overloading of the supporting bearings. In general, the bending deflection of a shaft should not exceed 0.01 in. per ft. of length between bearing supports.For diameters less than 3 in., the usual shaft material is cold-rolled steel containing about 0.4 percent carbon. Shafts are either cold-rolled or forged in sizes from 3 in. to 5 in. .For sizes above 5 in. , shafts are forged and machined to size. Plastic shafts are widely used for light load applications. One advantage of using plastic is safety in electrical applications, since plastic is a poor conductor of electricity.Another important aspect of shaft design is the method of directly connecting one shaft to another. This is accomplished by devices such as rigid and flexible couplings.BearingA bearing can be defined as a member specifically designed to support moving machine components. The most common bearing application is the support of a rotating shaft that is transmitting power from one location to another. Since there is always relative motion between a bearing and its mating surface, friction is involved. In many instances, such as the design of pulleys, brakes, and clutches, friction is desirable. However, in the case of bearings, the reduction of friction is one of the prime considerations：Friction results in loss of power, the generation of heat, and increased wear of mating surfaces.The concern of a machine designer with ball bearings and roller bearings is fivefold as follows：(1) Life in relation to load; (2) stiffness, i.e. deflections under load;(3) friction; (4) wear; (5) noise. For moderate loads and speeds the correct selection ofa standard bearing on the basis of load rating will usually secure satisfactoryperformance. The deflection of the bearing elements will become important where loads are high, although this is usually of less magnitude than that of the shafts or other components associated with the bearing. Where speeds are high special cooling arrangements become necessary which may increase frictional drag. Wear is primarily associated with the introduction of contaminants, and sealing arrangements must be chosen with regard to the hostility of the environment.Notwithstanding the fact that responsibility for the basic design of ball bearings and roller bearings rests with the bearing manufacturer, the machine designer must form a correct appreciation of the duty to be performed by the bearing and be concerned not only with bearing selection but with the conditions for correct installation.The fit of the bearing races onto the shaft or onto the housings is of critical importance because of their combined effect on the internal clearance of the bearing as well as preserving the desired degree of interference fit. Inadequate interference can induce serious trouble from fretting corrosion. The inner race is frequently located axially by abutting against a shoulder. A radius at this point is essential for the avoidance of stress concentration and ball races are provided with a radius or chamfer to allow space for this.A journal bearing, in its simplest form, is a cylindrical bushing made of a suitable material and containing properly machined inside and outside diameters. The journal is usually the part of a shaft or pin that rotates inside the bearing.Journal bearings operate with sliding contact, to reduce the problems associated with sliding friction in journal bearings, a lubricant is used in conjunction with compatible mating materials. When selecting the lubricant and mating materials, one must take into account bearing pressures, temperatures and also rubbing velocities. The principle function of the lubricant in sliding contact bearings is to prevent physical contact between the rubbing surfaces. Thus the maintenance of an oil film under varying loads, speeds and temperature is the prime consideration in sliding contact bearings.Introduction to Machinery DesignMachinery design is either to formulate an engineering plan for the satisfaction of a specified need or to solve an engineering problem. It involves a range of disciplines in materials, mechanics, heat, flow, control, electronics and production.Machinery design may be simple or enormously complex, easy or difficult, mathematical or nonmathematical, it may involve a trivial problem or one of great importance. Good design is the orderly and interesting arrangement of an idea to provide certain results or effects. A well-designed product is functional, efficient, and dependable. Such a product is less expensive than a similar poorly designed product that does not function properly and must constantly be repaired.People who perform the various functions of machinery design are typically called industrial designers. He or she must first carefully define the problem, using an engineering approach, to ensure that any proposed solution will solve the right problem. It is important that the designer begins by identifying exactly how he or she will recognize a satisfactory alternative, and how to distinguish between two satisfactory alternatives in order to identify the better. So industrial designers must have creative imagination, knowledge of engineering, production techniques, tools, machines, and materials to design a new product for manufacture, or to improve an existing product.In the modern industrialized world, the wealth and living standards of a nation are closely linked with their capabilities to design and manufacture engineering products. It can be claimed that the advancement of machinery design and manufacturing can remarkably promote the overall level of a country’s industrization. Our country is playing a more and more vital role in the global manufacturing industry. To accelerate such an industrializing process, highly skilled design engineers having extensive knowledge and expertises are needed.Machinery ComponentsThe major part of a machine is the mechanical system. And the mechanical system is decomposed into mechanisms, which can be further decomposed into mechanical components. In this sense, the mechanical components are the fundamental elements of machinery. On the whole, mechanical components can be classified as universal and special components. Bolts, gear, and chains are the typical examples of the universal components, which can be used extensively in different machines across various industrial sectors. Turbine blades, crankshaft and aircraftpropeller are the examples of the special components, which are designed for some specific purposes.Mechanical Design ProcessProduct design requires much research and development. Many concepts of an idea must be studied, tried, refined, and then either used or discarded. Although the content of each engineering problem is unique, the designers follow the similar process to solve the problems.Recognition of NeedSometimes, design begins when a designer recognizes a need and decides to do something about it. The need is often not evident at, all; recognition is usually triggered by a particular adverse circumstance or a set of random circumstances, which arise almost simultaneously. Identification of need usually consists of an undefined and vague problem statement.Definition of ProblemDefinition of problem is necessary to fully define and understand the problem, after which it is possible to restate the goal in a more reasonable and realistic way than the original problem statement. Definition of the problem must include all the specifications for the thing that is to be designed. Obvious items in the specifications are the speeds, feeds, temperature limitations, maximum range, expected variation in the variables, and dimensional and weight limitations.SynthesisThe synthesis is one in which as many alternative possible design approaches are sought, usually without regard for their value or quality. This is also sometimes called the ideation and invention step in which the largest possible number of creative solutions is generated. The synthesis activity includes the specification of material, addition of geometric features, and inclusion of greater dimensional detail to the aggregate design.AnalysisAnalysis is a method of determining or describing the nature of something by separating it into its parts. In the process the elements, or nature of the design, are analyzed to determine the fit between the proposed design and the original design goals.EvaluationEvaluation is the final proof of a successful design and usually involves thetesting of a prototype in the laboratory. Here we wish to discover if the design really satisfies the needs.The above description may give an erroneous impression that this process can be accomplished in a linear fashion as listed. On the contrary, iteration is required within the entire process, moving from any step back to any previous step, in all possible combinations, and doing this repeatedly.PresentationCommunicating the design to others is the finial, vital presentation step in the design process. Basically, there are only three means of communication. These are the written, the oral, and the graphical forms. A successful engineer will be technically competent and versatile in all three forms of communication. The competent engineer should not be afraid of the possibility of not succeeding in a presentation. In fact, the greatest gains are obtained by those willing to risk defeat.Contents of Machinery DesignMachinery design is an important technological basic course in mechanical engineering education. Its objective is to provide the concepts, procedures, data, and decision analysis techniques necessary to design machine elements commonly found in mechanical devices and systems; to develop engineering students’ competence of machine design that is the primary concern of machinery manufacturing and the key to manufacture good products.Machinery design covers the following contents：Provides an introduction to the design process, problem formulation, safety factors.Reviews the material properties and static and dynamic loading analysis, including beam, vibration and impact loading.Reviews the fundamentals of stress and defection analysis.Introduces static failure theories and fracture-mechanics analysis for static loads.Introduces fatigue-failure theory with the emphasis on stress-life approaches to high-cycle fatigue design, which is commonly used in the design of rotation machinery.Discusses thoroughly the phenomena of wear mechanisms, surface contact stresses, and surface fatigue.Investigates shaft design using the fatigue-analysis techniques.Discusses fluid-film and rolling-element bearing theory and application.Gives a thorough introduction to the kinematics, design and stress analysis of spur gears, and a simple introduction to helical, bevel, and worm gearing.Discusses spring design including helical compression, extension and torsion springs.Deals with screws and fasteners including power screw and preload fasteners.Introduces the design and specification of disk and drum clutches and brakes.机械零件(I)齿轮齿轮是直接接触，成对工作的实体，在称为齿的凸出物的连续啮合作用下，齿轮能将运动和力从一个旋转轴传递到另一个旋转轴，或从一个轴传递到一个滑块(齿条)。

Analysis based on the ANSYS metal gears and plastic gears inherentvibration characteristics compared姓名：班级：Abstract: Using ANSYS software gear finite element model, modal analysis, the plastic gear gun and steel gear module .State of natural frequencies and mode shapes diagram, were analyzed. The conclusion for the dynamic design of gears and gear structure related equipment fault diagnosisOff basis.Key words: plastic gear steel gear gun modal analysis of vibration characteristics 0 IntroductionThe gear drive is the most important in the mechanical transmission drive gear transmission because of its high efficiency, compact structure, the transmission ratio stable and are widely used in engineering. Accelerated due to the development of high-performance engineering plastics, the proportion of the application process for plastic and steel, plastics in the field of mechanical engineering is increasing, the production of gear materials are no longer limited to metallic materials, has grown to the plastic gear. On the application and theoretical study of the plastic gears, and steel gear, late research time is also shorter, and domestic and foreign researchers on the understanding of the plastic gear performance and application very immature, but to imitate and improve ['] on the basis of the steel gear. Therefore, the experimental study of plastic gear is necessary. Plastic material with Bo, the elastic energy, and thus has obvious noise reduction and vibration damping performance. In fact, for the transmission of power in terms of gear when the gear body's natural frequencies and the frequency of exciting force is very close to the even drill the plastic material gear also have a resonance and noise [[2}}} 4321-437A. Therefore, during the plastic gear design, the vibration characteristics of the study is necessary. We use ANSYS software to gear finite element model, modal analysis, mode shapes and natural frequency of the plastic gears and alloy gear to provide a basis for the structural design and optimization of gear.1 A gear modal analysisModal analysis is used to determine the natural frequency of the vibration characteristics of structures or machine parts in the design and mode shapes. Withstand dynamic bearing load structure design parameters [3] 4321-4324. Finite element analysis software ANSYS, modal analysis is a linear analysis of prestressed structure and cyclic symmetry structure modal analysis, modal analysis process is divided into four steps: modeling, loading and solving, extended modal and results post-processing.1.1 gear finite element modelANSYS provides three kinds of ways: to generate a model generation method with ANSYS to create solid model, the model established by the input model system. The direct generation method suitable for small, simple model, the leaders of the other systems if the model is not suitable for meshing, requires a lot of repair work. Gear model is relatively complex, suitable for solid modeling method. Known by the finite element theory, the solid model can not be directly used for finite element calculation, so take it mesh to generate a finite element model, the mesh will directly affect the accuracy of the finite element calculation results .Define the element type for the Structural solid Brick 2 (} node 95, the input gear parameters, create the key points, connecting key points generated gear contour, gear tooth surface generated by the contour, surface generation bodies drag along the segment, showing a single tooth geometric mode} 'J, division of a single tooth mesh gear is the structure of the body of the loop extension cycle to generate the finite element model of the plastic gears in Figure 1 shows, the finite element model of the number of nodes on a single tooth 3f} tS8 . unit number 1994.1.2 gear finite element model of the moldState analysisModal analysis of ANSYS, you must specify the elastic modulus EX. ANSYS11.0 seven kinds of modal extraction method: the Block Ianczoe (block, t the sos France), Subspace is (subspace method) I'owerDvnamics (source of power law), Reduced (reduction method), Un2symmetric (non-symmetric France), the Dam Network (damping France), QRDam network (Qlt damping method). In this article to Block lanczos method to extract modal..Gear model is built, its modal analysis, modal analysis of the gear. Purpose is to find the order natural frequency of the gear and its corresponding vibration mode, and therefore does not need to load, only degrees of freedom constraints. Constraints: the gear inner hole circle cylinder constraint: s:. Set of modal extraction method for the Block Canczos France, set up to extract the number of modes of 5 want to get the unit to solve the results need to open "the calculate elem re-salts, the frequency range specified modal extraction 0 100 000, specify the mode state extraction method, ANSYS automatically select the appropriate equation solver.Figure 1 gear finite element modelSolve the calculations are complete, view the solution results. Modal analysis results in order to get the whole gear model, the modal expansion, extended for solving the advantages of each order, for the obtained natural frequency. Solving r its corresponding mode shape is reflected in the natural frequency of each node of the gear relative displacement and relative stress conditions. Set the mode of state expansion, extended frequency range 0 100 000. Again into the solver to calculate and view the solution results, including the natural frequency, r, has been extended modes and the corresponding relative)> il, power distribution2 Define the material properties2.1 Structure of alloy steelAlloy steel with high strength, high toughness, wear resistance, corrosion resistance, low temperature, high temperature, non-magnetic and other special properties. Used to produce withstand dynamic load and heavy load of automobile transmission gear and car rear axle gear commonly used in power transmission, and high reliability of mechanical equipment in the 2.2 engineering materials.Engineering materials, plastic is characterized by: (1) self-lubrication, lubrication operation when necessary; (2) to reduce noise; ③light weight with excellentcorrosion resistance of two-phase metal gears, plastic gears, light weight industrial noise , resistant to wear, no lubrication, forming a more complex shape, mass production and low cost but because of two plastic itself is demanding, the work environment more sensitive to temperature, the relative metal strength is weak. Thus, the plastic gear at the same time have low accuracy, short life, the use of environmental requirements of the disadvantages. 'Article lists the parameters and material parameters of the mechanical properties of the two materials.3 the two materials modal analysis results and compare3.1 Modal analysis resultsAfter the definition of material properties, the modal analysis of finite element model of the gear to get before the modal natural frequency to enter PaSI'1 processor to view the solution results from the results seen, the mode shapes of the plastic gears with alloy steel gear the same type listed gear mode shapes shown in Figure 2..Figure 2 modal graphTo reverse the type, the axis of its deformation in the end face of the performance for the relative torsional vibration mode; modal performance for radial vibration: the vibration of the side surface showing polygon shapes, almost no axial vibration. Due to space limitations, gear vibration data not shown, the vibration mode shapes of folded shapes, the performance of axial rules of wave modes, the rule in the end face of the polygon shapes.4 gear natural frequency testPercussion method and the two kinds of resonance method, using the percussion method is usually used to test the gear natural frequency, and specific practices: test gear is hung with a thin non-metallic line up, with adhesive accelerometer installed inthe the gear face, followed by a charge amplifier to amplify the signal, the output signal through the the oscillator light oscilloscopes records will be collected vibration signal input spectrum analyzer, and then playback the signal on the oscilloscope to spectrum analyzer, and then fast Fourier any TT ) transform to obtain its transfer function. Will be repeatedly measured transfer function curve fitting and parameter identification, can be obtained by the test-gear vibration modal parameters (natural frequencies, mode shapes, damping ratio, etc.).5 ConclusionANSYS software gear finite element model, modal analysis, and the two materials Gear modal analysis results were compared. The following conclusions: ①plastic gears with steel gears, the maximum stress in the two-tooth gap tooth root parts of the gear tooth root parts to withstand the maximum load, but the maximum stress of the alloy steel gear is much larger than the maximum stress of plastic gear value is about 103 times. The minimum stress in the gear shaft fixed position. The ② relative to the steel gear, plastic gear natural frequency is low; two materials gear order modal frequency tended to increase with the order increases, and obtained the plastic gears with steel gears, the natural frequencies and mode shapes type, to test the final analysis, the calculation results with the experimental results, created using the ANSYS model and computational results are correct.来源：JH.MINGTING;Analysis based on the ANSYS metal gears and plastic gears inherent vibration characteristics compared; MATERIALS SCIENCE 38 (2003)339–341外文翻译基于ANSYS的金属齿轮与塑料齿轮固有振动特性的对比分析姓名：**班级：**摘要:用ANSYS软件建立齿轮有限元模型，对其进行模态分析，分别得到塑料齿枪与钢质齿轮模态的固有频率和振型图，进行对比分析。

机械英语-齿轮英语句子和术语一、齿轮英语句子1. At first, based on the analysis of the character of the tooth profile of Archimedes worm wheel, we prove that there is a unique common normal to the whole profile本文首先从分析阿基米德蜗轮齿面特性出发，论述了阿基米德蜗轮公法线在蜗轮齿面上的唯一性，并推导了阿基米德蜗轮公法线计算公式；2. It is important to ensure that the anchorage point can withstand the forces applied的。

3. Knowing the strength, it is possible to work backward and determine what factor of 由于知道其强度，便可以反过来求出所用的安全系数值。

4.Safe load capacity, strengths and application limits of accessories and components5.The deformation significantly increases electron mobility, making it possible to boost computer speed and reduce energy consumption.6.Although the cycloidal gear has much merits , the pure cycloidal gear is less used in正摆线齿轮。

7.Based on the tooth profile curve equation of inner rotors in cycloidal pump, the根据摆线泵内转子的齿廓曲线方程，推导出了摆线泵的排量计算公式。

齿在轴向的宽度。

齿腹：节圆和齿底之间的表面。

斜齿轮：这些齿轮的齿相对于齿轮轴线由一个角度或螺旋角度，它们比直齿圆柱齿轮的制造更难，造价更昂贵，但是它们传动无噪音并且可靠。

它们可以用来在相同或不同平面中构成一定角度的相两轴之间的力的传递。

人字形齿轮：人字形齿轮是在齿轮两边有相同数量在左旋和右旋形的齿轮。

由于齿轮有角度，齿轮制造时需要考虑轴受到的轴向力，人字形齿轮是用平衡的方法来抵消轴向推力的，固而允许选用轻系列轴承取代重系列轴承，甚至可以完全取消轴承，通常在切削加工中在齿轮的周围有一个中心槽来抵消。

锥齿轮：锥齿轮用作互相不平行的轴之间的连接。

通常轴之间的夹角是90度，但它们比90多或少，相啮合的两齿轮仅改变运动方向，或者为改变速度具有不同的齿数，齿的表面沿着圆锥的表面，圆头齿之间不相互平行，它就使得在机械加工中产生类似的问题及必须要一套夹具。

齿轮的线可能是直的或螺旋的，因此有平直的锥齿和螺旋的锥齿。

蜗杆和蜗轮：蜗杆蜗轮机构主要用作有限空间需较小齿轮的体积的情况。

通常蜗杆为主动件并且不能颠倒，也就是说，蜗轮不能作为主动件。

许多蜗杆能左右移动，转动为顺时针或逆时针。

齿条：齿条是有无穷半径的齿轮或是边缘随着直线扩展的齿轮，它被用来往复运动改变为螺旋运动或反过来，车床齿条和小齿轮是这种机器的最好例子。

各种材料被用于制造齿轮。

通常被选用的材料取决于齿轮的制造与齿轮将来的实现用途，齿轮能被铸，轧或挤压出来。

材料类型包括：铸铁碳素钢，合金钢，铝，青铜，尼龙。

附录：GearsAbstract: Gear is power element in the machine, is used to pass between the shaft and shaft movement and power. They may just was used to relay movement, that is one part to another part of the machine, or be used to change the relative spee d and torque between shaft and shaft, the first to be discovered with gear machine is horological, in fact, the gear of the clock is very small compared with the gear train. As the widely used in the gear in the actual environment, people in the asp ect of the application of the gear for a lot of research and investigation. now, gear drive than ever to have to pass a heavy load, and under the high speed running. The engineers and mechanics are considering the factors that exist in a mechanical.Keywords: Gear，Strength，check.Super Gears：Spur gears will be considered first for several reasons.In the first place ,they are simplest and the least expensive of gears and they may be used to transmit power betw een parallel shafts,also,spur gears definitions are usually applicable to other types .It is imp ortant go understand the following definitions,since they are important factors in the desig n of any equipment utilizing gears. Diametric Pitch The number of teeth per inch of pitch cirle diameter .The diameter pitch is usually an integer .A small number for the pitch imp lies a large tooth size.Meshing spur gears must have the same diameter pitch .The speed rat io is based on the fact that meshing gears may have different-sized pitch circles and henc e different number of teeth.Circular Pitch：The distance from a point on one tooth to the corresponding point on an adjacent tooth ,m easrued along the pitch circle.This is a liner dimension and thus bas liner units.Pitch Circle：The circle on which the ratio of the gear set is based,when two gears are meshing ,the tw o pitch circles must be exactly tangent if the gears are to function properly.The tangency p oint is known as the pitch point.Pressure Angle：The angle between the line of action and a line perpendicular to the centerlines of the tw o gears in mesing .Pressure Angles for spur gears are usually 14.5 or 20 degrees,although o ther values can be used.Meshing gears must have the same pressure angles.In the case of a rack,the teeth have the straight sides inclined at an angle corresponding to the pressure a ngle.Base Circle：A circle tangent to the line of action (or pressure line ) .The base circle is the imaginary cir cle about which an involutes cure is developed .Most spur gears follow an involutes cure fr om the base circle to the top of the tootch,this cure can be visualized by observing a point o n a taut cord an it is unwound from a cylinder .In a gear ,the cylinder is the best circle.Addendum：The radial distance form the pitch circle to the top of the tooth .Dedendum：The radial distance from file pitch circle to the root of the tooth.Clearance：The difference between the addendum and the addendum.Face Width：The width of the tooth measured axially.Face：The surface between the pitch circle and the top of the tooth.Flank：The surface between the pitch circle and the bottom of the tooth.Helical Gears：These gears have their tooth element at an angle or helix to the axis of the gear.The-y are more difficult and expensive to make than spur gears,but are quieter and stronger. They may be used to transmit power between parallel shafts at an angle to each in the same o r different planes.Herringbone Gears：A herringbone gear is equivalent to a right-hand and a left-hand helical gear placed side b y side.Because of the angle of the tooth,helicalgears create considerable side thrust on the shaft. A herringbone gear corrects this thrust b y neutralizing it ,allowing the use of a small thrust bearing instead of a large one and perha ps eliminating one altogether.Often a central groove is made round the gear for ease in mac hining.Bevel Gears：Bevel gears are used to connect shafts, which are not parallel to each ually the sha fts are 90 deg.To each other, but they may be more or less than 90 deg.The two meshing ge ars may have the same number of teeth for the purpose of changing direction of motion onl y,or they may have a different number of teeth for the purpose of changing both speed an d irection .The faces of the teeth lie on the surface of the frustum of a cone,therefore the te eth elements are not parallel to each other it can be seen that this lack of parallelism create s a machining problem so that two passes with a tool must be made.The tooth elements ma y be straight or spiral ,so that we have plain anti spiral evel gears.Worm and Worm Gears：A worm-and-worm-gear combination is used chiefly where it is desired to obtain a high ge ar reduction in a limited space,normally the worm drivers the worm gear and is not reversi ble ,that is to say,the worm gear can not drivethe worm.Most worms can be rotated in either direction,clockwise or counterclockwise. Ra cks A rack is a gear with an infinite radius,or a gear with its perimeter stretched out into a straight line.It is used to change reciprocating motion to rotary motion or vice versa.A l athe rack and pinion is a good example of this mechanism.Various materials are used in manufacturing gears.Usually,the materials selected depends on the method used for making the gear and the ap注：1. 指导教师对译文进行评阅时应注意以下几个方面：①翻译的外文文献与毕业设计（论文）的主题是否高度相关，并作为外文参考文献列入毕业设计（论文）的参考文献；②翻译的外文文献字数是否达到规定数量（3 000字以上）；③译文语言是否准确、通顺、具有参考价值。

机械制造毕业设计外文英文文献翻译齿轮和齿轮传动Gears and gear driveGears are the most durable and rugged of all mechanical drives. They can transmit high power at efficiencies up to 98% and with long service lives. For this reason, gears rather than belts or chains are found in automotive transmissions and most heavy-duty machine drives. On the other hand, gears are more expensive than other drives, especially if they are machined and not made from power metal or plastic.Gear cost increases sharply with demands for high precision and accuracy. So it is important to establish tolerance requirements appropriate for the application. Gears that transmit heavy loads or than operate at high speeds are not particularly expensive, but gears that must do both are costly.Silent gears also are expensive. Instrument and computer gears tend to be costly because speed or displacement ratios must be exact. At the other extreme, gears operating at low speed in exposed locations are normally termed no critical and are made to minimum quality standards.For tooth forms, size, and quality, industrial practice is to follow standards set up by the American Gear Manufactures AssociationAGMA.Tooth formStandards published by AGMA establish gear proportions and tooth profiles. Tooth geometry is determined primarily by pitch, depth, and pressure angle.Pitch：Standards pitches are usually whole numbers when measured as diametral pitch P. Coarse-pitch gearing has teeth larger than 20 diametral pitch ?usually 0.5 to 19.99. Fine-pitch gearing usually has teeth of diametral pitch 20 to 200.Depth: Standardized in terms of pitch. Standard full-depth have working depth of 2/p. If the teeth have equal addendaas in standard interchangeable gears the addendum is 1/p. Stub teeth have a working depth usually 20% less than full-depth teeth. Full-depth teeth have a larger contract ratio than stub teeth. Gears with small numbers of teeth may have undercut so than they do not interfere with one another during engagement. Undercutting reduce active profile and weakens the tooth.Mating gears with long and short addendum have larger load-carrying capacity than standard gears. The addendum of the smaller gear pinion is increased while that of larger gear is decreased, leaving the whole depth the same. This form is know as recess-action gearing.Pressure Angle: Standard angles are and . Earlier standards include a 14-pressure angle that is still used. Pressure angle affectsthe force that tends to separate mating gears. High pressure angle decreases the contact ratio ratio of the number of teeth in contact but provides a tooth of higher capacity and allows gears to have fewer teeth without undercutting.Backlash: Shortest distances between the non-contacting surfaces of adjacent teeth .Gears are commonly specified according to AGMA Class Number, which is a code denoting important quality characteristics. Quality number denote tooth-element tolerances. The higher the number, the closer the tolerance. Number 8 to 16 apply to fine-pitch gearing.Gears are heat-treated by case-hardening, through-hardening, nitriding, or precipitation hardening. In general, harder gears are stronger and last longer than soft ones. Thus, hardening is a device that cuts the weight and size of gears. Some processes, such as flame-hardening, improve service life but do not necessarily improve strength.Design checklistThe larger in a pair is called the gear, the smaller is called the pinion.Gear Ratio: The number of teeth in the gear divide by the number of teeth in the pinion. Also, ratio of the speed of the pinion to the speed of the gear. In reduction gears, the ratio of input to output speeds.Gear Efficiency: Ratio of output power to input power. includesconsideration of power losses in the gears, in bearings, and from windage and churning of lubricant.Speed: In a given gear normally limited to some specific pitchline velocity. Speed capabilities can be increased by improving accuracy of the gear teeth and by improving balance of the rotating parts.Power: Load and speed capacity is determined by gear dimensions and by type of gear. Helical and helical-type gears have the greatest capacity to approximately 30,000 hp. Spiral bevel gear are normally limited to 5,000 hp, and worm gears are usually limited to about 750 hp.Special requirementsMatched-Set Gearing: In applications requiring extremely high accuracy, it may be necessary to match pinion and gear profiles and leads so that mismatch does not exceed the tolerance on profile or lead for the intended application.Tooth Spacing: Some gears require high accuracy in the circular of teeth. Thus, specification of pitch may be required in addition to an accuracy class specification.Backlash: The AMGA standards recommend backlash ranges to provide proper running clearances for mating gears. An overly tight mesh may produce overload. However, zero backlash is required in some applications.Quiet Gears: To make gears as quit as possible, specify thefinest pitch allowable for load conditions. In some instances, however, pitch is coarsened to change mesh frequency to produce a more pleasant, lower-pitch sound. Use a low pressure angle. Use a modified profile to include root and tip relief. Allow enough backlash. Use high quality numbers. Specify a surface finish of 20 in. or better. Balance the gear set. Use a nonintegral ratio so that the same teeth do not repeatedly engage if both gear and pinion are hardened steel. If the gear is made of a soft material, an integral ratio allows the gear to cold-work and conform to the pinion, thereby promoting quiet operation. Make sure critical are at least 20% apart from operating speeding or speed multiples and from frequency of tooth mesh.Multiple mesh gearMultiple mesh refers to move than one pair of gear operating in a train. Can be on parallel or nonparallel axes and on intersection or nonintersecting shafts. They permit higer speed ratios than are feasible with a single pair of gears .Series trains:Overall ratio is input shaft speed divided by output speed ,also the product of individual ratios at each mesh ,except in planetary gears .Ratio is most easily found by dividing the product of numbers of teeth of driven gears by the product of numbers of teeth of driving gears.Speed increasers with step-up rather than step-down ratios mayrequire special care in manufacturing and design. They often involve high speeds and may creste problems in gear dynamics. Also, frictional and drag forces are magnified which, in extreme cases , may lead to operational problems.Epicyclic Gearing:Normally, a gear axis remains fixed and only the gears rotates. But in an epicyclic gear train, various gears axes rotate about one anther to provide specialized output motions. With suitable clutchse and brakes, an epicyclic train serves as the planetary gear commonly found in automatic transmissions.Epicyclic trains may use spur or helical gears, external or internal, or bevel gears. In transmissions, the epicyclic or planetary gears usually have multiple planets to increase load capacity.In most cases, improved kinematic accuracy in a gearset decreases gear mesh excitation and results in lower drive noise. Gearset accuracy can be increased by modifying the tooth involute profile, by substituting higher quality gearing with tighter manufacturing tolerances, and by improving tooth surface finish. However, if gear mesh excitation generaters resonance somewhere in the drive system, nothing short of a “perfect” gearset will substantially reduce vibration and noise.Tooth profiles are modified to avoid interferences which can result from deflections in the gears, shafts, and housing as teeth engageand disendgage. If these tooth interferences are not compensated for by profile modifications, gears load capacity can be seriously reduced. In addition, the drive will be noisier because tooth interferences generate high dynamic loads. Interferences typically are eliminated by reliving the tooth tip, the tooth flank, or both. Such profile modifications are especially important for high-load , high-speed drives. The graph of sound pressure levelvs tip relief illustrates how tooth profile modifications can affect overall drive noise. If the tip relief is less than this optimum value, drive noise increases because of greater tooth interference; a greater amount of tip relief also increase noise because the contact ratio is decreased.Tighter manufacturing tolerances also produce quietier gears. Tolerances for such parameters as profile error, pitch AGMA quality level. For instance, the graph depicting SPL vs both speed and gear quality shows how noise decreases example, noise is reduced significantly by an increase in accuracy from an AGMA Qn 11 quality to an AGNA Qn 15 quality. However, for most commercial drive applications, it is doubtful that the resulting substantial cost increase for such an accuracy improvement can be justified simply on the basis of reduced drive noise.Previously, it was mentioned that gears must have adequate clearance when loaded to prevent tooth interference during the course of meshing. Tip and flank relief are common profile modifications thatcontrol such interference. Gears also require adequate backlash and root clearance. Noise considerations make backlash an important parameter to evaluate during drive design. Sufficient backlash must be provided under all load and temperature conditions to avoid a tight mesh, which creates excessively high noise level. A tight mesh due to insufficient backlash occurs when the drive and coast side of a tooth are in contact simultaneously. On the other hand, gears with excessive backlash also are noisy because of impacting teeth during periods of no load or reversing load. Adequate backlash should be provided by tooth thinning rather than by increase in center distance. Tooth thinning dose not decrease the contact ratio, whereas an increase in center distance does. However, tooth thinning does reduce the bending fatigue, a reduction which is small for most gearing systems.齿轮和齿轮传动在所有的机械传动形式中，齿轮传动是一种最结实耐用的传动方式。

毕业设计论文外文资料原文及译文学院：机电工程学院专业：机械设计制造及其自动化班级：学号：姓名：Mechanical engineering1.The porfile of mechanical engineeringEngingeering is a branch of mechanical engineerig,it studies mechanical and power generation especially power and movement.2.The history of mechanical engineering18th century later periods,the steam engine invention has provided a main power fountainhead for the industrial revolution,enormously impelled each kind of mechznical biting.Thus,an important branch of a new Engineering – separated from the civil engineering tools and machines on the branch-developed together with Birmingham and the establishment of the Associantion of Mechanical Engineers in 1847 had been officially recognized.The mechanical engineering already mainly used in by trial and error method mechanic application technological development into professional engineer the scientific method of which in the research,the design and the realm of production used .From the most broad perspective,the demend continuously to enhance the efficiencey of mechanical engineers improve the quality ofwork,and asked him to accept the history of the high degree of education and training.Machine operation to stress not only economic but also infrastructure costs to an absolute minimun.3.The field of mechanical engineeringThe commodity machinery development in the develop country,in the high level material life very great degree is decided each kind of which can realize in the mechanical engineering.Mechanical engineers unceasingly will invent the machine next life to produce the commodity,unceasingly will develop the accuracy and the complexity more and more high machine tools produces the machine.The main clues of the mechanical development is:In order to enhance the excellent in quality and reasonable in price produce to increase the precision as well as to reduce the production cost.This three requirements promoted the complex control system development.The most successful machine manufacture is its machine and the control system close fusion,whether such control system is essentially mechanical or electronic.The modernized car engin production transmission line(conveyer belt)is a series of complex productions craft mechanizationvery good example.The people are in the process of development in order to enable further automation of the production machinery ,the use of a computer to store and handle large volumes of data,the data is a multifunctional machine tools necessary for the production of spare parts.One of the objectives is to fully automated production workshop,three rotation,but only one officer per day to operate.The development of production for mechanical machinery must have adequate power supply.Steam engine first provided the heat to generate power using practical methods in the old human,wind and hydropower,an increase of engin .New mechanical engineering industry is one of the challenges faced by the initial increase thermal effciency and power,which is as big steam turbine and the development of joint steam boilers basically achieved.20th century,turbine generators to provide impetus has been sustained and rapid growth,while thermal efficiency is steady growth,and large power plants per kW capital consumption is also declining.Finally,mechanical engineers have nuclear energy.This requires the application of nuclear energy particularly high reliability and security,which requires solving many new rge power plants and the nuclear power plant control systems have become highly complex electroonics,fluid,electricity,water and mechanical parts networks All in all areas related to the mechanical engineers.Small internal combustion engine,both to the type (petrol and diesel machines)or rotary-type(gas turbines and Mong Kerr machine),as well as their broad application in the field of transport should also due to mechanical enginerrs.Throughout the transport,both in the air and space,or in the terrestrial and marine,mechanial engineers created a variety of equipment and power devices to their increasing cooperation with electrical engineers,especially in the development of appropration control systems.Mechanical engineers in the development of military weapons technology and civil war ,needs a similar,though its purpose is to enhance rather than destroy their productivity.However.War needs a lot of resources to make the area of techonlogy,many have a far-reaching development in peacetime efficiency.Jet aircraft and nuclear reactors are well known examples.The Biological engineering,mechanical engineering biotechnology is a relatively new and different areas,it provides for the replacement of the machine or increase thebody functions as well as for medical equipment.Artficial limbs have been developed and have such a strong movement and touch response function of the human body.In the development of artificial organ transplant is rapid,complex cardiac machines and similar equipment to enable increasingly complex surgery,and injuries and ill patients life functions can be sustained.Some enviromental control mechanical engineers through the initial efforts to drainage or irrigation pumping to the land and to mine and ventilation to control the human environment.Modern refrigeration and air-conditioning plant commonaly used reverse heat engine,where the heat from the engine from cold places to more external heat.Many mechanical engineering products,as well as other leading technology development city have side effects on the environment,producing noise,water and air pollution caused,destroyed land and landscape.Improve productivity and diver too fast in the commodity,that the renewable naturalforces keep pace.For mechanical engineers and others,environmental control is rapidly developing area,which includes a possible development and production of small quantities of pollutants machine sequnce,and the development of new equipment and teachnology has been to reduce and eliminate pollution.4.The role of mechanical engineeringThere are four generic mechanical engineers in common to the above all domains function.The 1st function is the understanding and the research mechanical science foundation.It includes the power and movement of the relationship dynamics For example,in the vibration and movement of the relationship;Automatic control;Study of the various forms of heart,energy,power relations between the thermodynamic;Fluidflows; Heat transfer; Lubricant;And material properties.The 2nd function will be conducts the research,the desing and the development,this function in turn attempts to carry on the essential change to satisfy current and the future needs.This not only calls for a clear understanding of mechanical science,and have to breakdown into basic elements of a complex system capacity.But also the need for synthetic and innovative inventions.The 3rd function is produces the product and the power,include plan,operation and maintenance.Its goal lies in the maintenance eitherenhances the enterprise or the organization longer-tern and survivabilaty prestige at the same time,produces the greatest value by the least investments and the consumption.The 4th function is mechanical engineer’s coordinated function,including the management,the consultation,as well as carries on the market marking in certain situation.In all these function,one kind unceasingly to use the science for a long time the method,but is not traditional or the intuition method tendency,this is a mechanical engineering skill aspect which unceasingly grows.These new rationalization means typical names include:The operations research,the engineering economics,the logical law problem analysis(is called PABLA) However,creativity is not rationalization.As in other areas,in mechanical engineering,to take unexpected and important way to bring about a new capacity,still has a personal,marked characteristice.5.The design of mechanical engineeringThe design of mechanical is the design has the mechanical property the thing or the system,such as:the instrument and the measuring appliance in very many situations,the machine design must use the knowledge of discipline the and so on mathematics,materials science and mechanics.Mechanical engineering desgin includeing all mechanical desgin,but it was a study,because it also includes all the branches of mechsnical engineering,such as thermodynamics all hydrodynamics in the basic disciplines needed,in the mechanical engineering design of the initial stude or mechanical design.Design stages.The entire desgin process from start to finish,in the process,a demand that is designed for it and decided to do the start.After a lot of repetition,the final meet this demand by the end of the design procees and the plan.Design considerations.Sometimes in a system is to decide which parts needs intensity parts of geometric shapesand size an important factor in this context that we must consider that the intensity is an important factor in the design.When we use expression design considerations,we design parts that may affect the entire system design features.In the circumstances specified in the design,usually for a series of such functions must be taken into account.Howeever,to correct purposes,we should recognize that,in many cases thedesign of important design considerations are not calculated or test can determine the components or systems.Especially students,wheen in need to make important decisions in the design and conduct of any operation that can not be the case,they are often confused.These are not special,they occur every day,imagine,for example,a medical laboratory in the mechanical design,from marketing perspective,people have high expectations from the strength and relevance of impression.Thick,and heavy parts installed together:to produce a solid impression machines.And sometimes machinery and spare parts from the design style is the point and not the other point of view.Our purpose is to make those you do not be misled to believe that every design decision will needreasonable mathematical methods.Manufacturing refers to the raw meterials into finished products in the enterprise.Create three distinct phases.They are:input,processing exprot.The first phase includes the production of all products in line with market needs essential.First there must be the demand for the product,the necessary materials,while also needs such as energy,time,human knowledge and technology resourcess .Finall,the need for funds to obtain all the other resources. Lose one stage after the second phase of the resources of the processes to be distributed.Processing of raw materials into finished products of these processes.To complete the design,based on the design,and then develop plans.Plan implemented through various production processes.Management of resources and processes to ensure efficiency and productivity.For example,we must carefully manage resources to ensure proper use of funds.Finally,people are talking about the product market was cast.Stage is the final stage of exporting finished or stage.Once finished just purchased,it must be delivered to the users.According to product performance,installation and may have to conduct further debugging in addition,some products,especially those very complex products User training is necessary.6.The processes of materials and maunfacturingHere said engineering materials into two main categories:metals and non-ferrous,high-performance alloys and power metals.Non-metallic futher divided into plastice,synthetic rubber,composite materials and ceramics.It said the productionproccess is divided into several major process,includingshape,forging,casting/ founding,heat treatment,fixed/connections ,measurement/ quality control and materal cutting.These processes can be further divide into each other’s craft.Various stages of the development of the manufacturing industry Over the years,the manufacturing process has four distinct stages of development, despite the overlap.These stages are:The first phase is artisanal,the second Phase is mechanization.The third phase is automation the forth Phase is integrated.When mankind initial processing of raw materials into finished products will be,they use manual processes.Each with their hands and what are the tools manuslly produced.This is totally integrated production take shape.A person needs indentification,collection materials,the design of a product to meet that demand,the production of such products and use it.From beginning to end,everything is focused on doing the work of the human ter in the industrial revolution introduced mechanized production process,people began to use machines to complete the work accomplished previously manual. This led to the specialization.Specialization in turn reduce the manufacture of integrated factors.In this stage of development,manufacturing workers can see their production as a whole represent a specific piece of the part of the production process.One can not say that their work is how to cope with the entire production process,or how they were loaded onto a production of parts finished.Development of manufacting processes is the next phase of the selection process automation.This is a computer-controlled machinery and processes.At this stage,automation island began to emerge in the workshop lane.Each island represents a clear production process or a group of processes.Although these automated isolated island within the island did raise the productivity of indivdual processes,but the overall productivity are often not change.This is because the island is not caught in other automated production process middle,but not synchronous with them .The ultimate result is the efficient working fast parked through automated processes,but is part of the stagnation in wages down,causing bottlenecks.To better understand this problem,you can imagine the traffic in the peak driving a red light from the red Service Department to the next scene. Occasionally you will find a lot less cars,more than being slow-moving vehicles,but the results can be found by thenext red light Brance.In short you real effect was to accelerate the speed of a red Department obstruction offset.If you and other drivers can change your speed and red light simultaneously.Will advance faster.Then,all cars will be consistent,sommth operation,the final everyone forward faster.In the workshop where the demand for stable synchronization of streamlined production,and promoted integration of manufacturing development.This is a still evolving technology.Fully integrated in the circumstances,is a computer-controllrd machinery and processing.integrated is completed through computer.For example in the preceding paragraph simulation problems,the computer will allow all road vehicles compatible with the change in red.So that everyone can steady traffic.Scientific analysis of movement,timing and mechanics of the disciplines is that it is composed of two pater:statics and dynamics.Statics analyzed static system that is in the system,the time is not taken into account,research and analysis over time and dynamics of the system change.Dynameics from the two componets.Euler in 1775 will be the first time two different branches: Rigid body movement studies can conveniently divided into two parts:geometric and mechanics.The first part is without taking into account the reasons for the downward movement study rigid body from a designated location to another point of the movement,and must use the formula to reflect the actual,the formula would determine the rigid body every point position. Therefore,this study only on the geometry and,more specifically,on the entities from excision.Obviously,the first part of the school and was part of a mechanical separation from the principles of dynamics to study movement,which is more than the two parts together into a lot easier.Dynamics of the two parts are subsequently divided into two separate disciplines,kinematic and dynamics,a study of movement and the movement strength.Therefore,the primary issue is the design of mechanical systems understand its kinematic.Kinematic studies movement,rather than a study of its impact.In a more precise kinematic studies position,displacement,rotation, speed,velocity and acceleration of disciplines,for esample,or planets orbiting research campaing is a paradigm.In the above quotation content should be pay attention that the content of the Euler dynamics into kinematic and rigid body dynamics is based on the assumptionthat they are based on research.In this very important basis to allow for the treatment of two separate disciplines.For soft body,soft body shape and even their own soft objects in the campaign depends on the role of power in their possession.In such cases,should also study the power and movement,and therefore to a large extent the analysis of the increased complexity.Fortunately, despite the real machine parts may be involved are more or less the design of machines,usually with heavy material designed to bend down to the lowest parts.Therefore,when the kinematic analysis of the performance of machines,it is often assumed that bend is negligible,spare parts are hard,but when the load is known,in the end analysis engine,re-engineering parts to confirm this assnmption.机械工程1.机械工程简介机械工程是工程学的一个分支，它研究机械和动力的产，尤其是力和动力。

外文原文GearsGears are vital factors in machinery ,which are uses to transmit power or motion from one shaft to another .They may be used only to transmit motion from one part of a machine to another,or they may be used to change the speed or the torque of one shaft with with relation to another.One of the first mechanism invented using gears wad the clock.In fact,a clock is little more than a train of gears.Considerable study and research have been made on gears in recent years because of their wide use under exacting conditions.They have to transmit heavier loads and run at high speeds than ever before.The engineers and the machinists all consider gearing the prime element in nearly all classes of machinery.Super GearsSpur gears will be considered first for several reasons.In the first place ,they are simplest and the least expensive of gears and they may be used to transmit power between parallel shafts,also,spur gears definitions are usually applicable to other types .It is important go understand the following definitions,since they are important factors in the design of any equipment utilizing gears.Diametric PitchThe number of teeth per inch of pitch cirle diameter .The diameter pitch is usually an integer .A small number for the pitch implies a large tooth size.Meshing spur gears must have the same diameter pitch .The speed ratio is based on the fact that meshing gears may have different-sized pitch circles and hence different number of teeth.Circular PitchThe distance from a point on one tooth to the corresponding point on an adjacent tooth ,measrued along the pitch circle.This is a liner dimension and thus bas liner units.Pitch CircleThe circle on which the ratio of the gear set is based,when two gears are meshing ,the two pitch circles must be exactly tangent if the gears are to function properly.The tangency point is known as the pitch point. Pressure AngleThe angle between the line of action and a line perpendicular to the centerlines of the two gears in mesing .Pressure Angles for spur gears are usually 14.5 or 20 degrees,although other values can be used.Meshing gears must have the same pressure angles.In the case of a rack,the teeth have the straight sides inclined at an angle corresponding to the pressure angle.Base CircleA circle tangent to the line of action (or pressure line ) .The base circle is the imaginary circle about which an involutes cure is developed .Most spur gears follow an involutes cure from the base circle to the top of the tootch,this cure can be visualized by observing a point on a taut cord an it is unwound from a cylinder .In a gear ,the cylinder is the best circle.AddendumThe radial distance form the pitch circle to the top of the tooth . DedendumThe radial distance from file pitch circle to the root of the tooth. ClearanceThe difference between the addendum and the addendum.Face WidthThe width of the tooth measured axially.FaceThe surface between the pitch circle and the top of the tooth. FlankThe surface between the pitch circle and the bottom of the tooth. Helical GearsThese gears have their tooth element at an angle or helix to the axis of the gear.They are more difficult and expensive to make than spur gears,but are quieter and stronger. They may be used to transmit power between parallel shafts at an angle to each in the same or different planes.Herringbone GearsA herringbone gear is equivalent to a right-hand and a left-hand helical gear placed side by side.Because of the angle of the tooth,helical gears create considerable side thrust on the shaft. A herringbone gear corrects this thrust by neutralizing it ,allowing the use of a small thrust bearing instead of a large one and perhaps eliminating one altogether.Often a central groove is made round the gear for ease in machining.Bevel GearsBevel gears are used to connect shafts, which are not parallel to each ually the shafts are 90 deg.To each other, but they may be more or less than 90 deg.The two meshing gears may have the same number of teeth for the purpose of changing direction of motion only,or they may have a different number of teeth for the purpose of changing both speed and direction .The faces of the teeth lie on the surface of the frustum of a cone,therefore the teeth elements are not parallel to each other it can be seen that this lack of parallelism creates a machining problem so that two passes with a tool must be made.The tooth elements may be straight or spiral ,so that we have plain anti spiral evel gears.Worm and Worm GearsA worm-and-worm-gear combination is used chiefly where it is desired to obtain a high gear reduction in a limited space,normally the worm drivers the worm gear and is not reversible ,that is to say,the worm gear can not drive the worm.Most worms can be rotated in either direction,clockwise or counterclockwise.RacksA rack is a gear with an infinite radius,or a gear with its perimeter stretched out into a straight line.It is used to change reciprocating motion to rotary motion or vice versa.A lathe rack and pinion is a good example of this mechanism.Various materials are used in manufacturing gears .Usually,the materials selected depends on the method used for making the gear and the application to which it will be put.Gears can be cast,cut,or extruded.Typical materials include cast iron,cast steel,plain carbon steel,alloy steel aluminum,phosphor bronze,laminated phonetics,and nylon.中文翻译齿轮齿轮是机器中的动力元件,用来传递轴与轴之间的运动及动力。

Gear And Shaft IntroductionIn the force analysis of spur gears, the forces are assumed to act in a single plane. We shall study gears in which the forces have three dimensions. The reason for this, in the case of helical gears, is that the teeth are not parallel to the axis of rotation. And in the case of bevel gears, the rotational axes are not parallel to each other.Helical gears are used to transmit motion between parallel shafts. The helix angle is the same on each gear, but one gear must have a right-hand helix and the other a left-hand helix. The shape of the tooth is an involute helicoid. If a piece of paper cut in the shape of a parallelogram is wrapped around a cylinder, the angular edge of the paper becomes a helix. If we unwind this paper, each point on the angular edge generates an involute curve. The surface obtained when every point on the edge generates an involute is called an involute helicoid.The initial contact of spur-gear teeth is a line extending all the way across the face of the tooth. The initial contact of helical gear teeth is a point, which changes into a line as the teeth come into more engagement. In spur gears the line of contact is parallel to the axis of the rotation; in helical gears, the line is diagonal across the face of the tooth. It is this gradual of the teeth and the smooth transfer of load from one tooth to another, which give helical gears the ability to transmit heavy loads at high speeds. Helical gears subject the shaft bearings to both radial and thrust loads. When the thrust loads become high or are objectionable for otherreasons, it may be desirable to use double helical gears. A double helical gear (herringbone) is equivalent to two helical gears of opposite hand, mounted side by side on the same shaft. They develop opposite thrust reactions and thus cancel out the thrust load. When two or more single helical gears are mounted on the same shaft, the hand of the gears should be selected so as to produce the minimum thrust load.Crossed-helical, or spiral, gears are those in which the shaft centerlines are neither parallel nor intersecting. The teeth of crossed-helical fears have point contact with each other, which changes to line contact as the gears wear in. For this reason they will carry out very small loads and are mainly for instrumental applications, and are definitely not recommended f or use in the transmission of power. There is on difference between a crossed helical gear and a helical gear until they are mounted in mesh with each other. They are manufactured in the same way. A pair of meshed crossed helical gears usually have the same hand; that is ,a right-hand driver goes with a right-hand driven. In the design of crossed-helical gears, the minimum sliding velocity is obtained when the helix angle are equal. However, when the helix angle are not equal, the gear with the larger helix angle should be used as the driver if both gears have the same hand.Worm gears are similar to crossed helical gears. The pinion or worm has a small number of teeth, usually one to four, and since they completely wrap around the pitch cylinder they are called threads. Its mating gear is called a worm gear, which is not a true helical gear. A worm and worm gear are used to provide a highangular-velocity reduction between nonintersecting shafts which are usually at right angle. The worm gear is not a helical gear because its face is made concave to fit the curvature of the worm in order to provide line contact instead of point contact. However, a disadvantage o f worm gearing is the high sliding velocities across the teeth, the same as with crossed helical gears.Worm gearing are either single or double enveloping. A single-enveloping gearing is one in which the gear wraps around or partially encloses the worm.. A gearing in which each element partially encloses the other is, of course, a double-enveloping worm gearing. The important difference between the two is that area contact exists between the teeth of double-enveloping gears while only line contact between those of single-enveloping gears. The worm and worm gear of a set have the same hand of helix as for crossed helical gears, but the helix angles are usually quite different. The helix angle on the worm is generally quite large, andthat on the gear very small. Because of this, it is usual to specify the lead angle on the worm, which is the complement of the worm helix angle, and the helix angleon the gear; the two angles are equal for a 90-deg. Shaft angle.When gears are to be used to transmit motion between intersecting shaft, some of bevel gear is required. Although bevel gear are usually made for a shaft angle of 90 deg. They may be produced for almost any shaft angle. The teeth may be cast, milled, or generated. Only the generated teeth may be classed as accurate. In a typical bevel gear mounting, one of the gear is often mounted outboard of theWhen either the lateral or the torsional deflection of a shaft must be held to close limits, the shaft must be sized on the basis of deflection before analyzing the stresses. T he reason for this is that, if the shaft is made stiff enough so that the deflection is not too large, it is probable that the resulting stresses will be safe. But by no means should the designer assume t hat they are safe; it is almost always necessary t o calculate them so that he knows they are within acceptable limits. Whenever possible, the power-transmission elements, such as gears or pullets, should be located close to the supporting bebearing. This means that shaft deflection can be more pronounced and have a greater effect on the contact of teeth.A shaft is a rotating or stationary member, usually of circular cross section, having mounted upon it such elementsas gears, pulleys, flywheels, cranks, sprockets, and other power-transmission elements. Shaft may be subjected to bending, tension, compression, or torsional loads, acting singly or in combination with one another. When they are combined, one may expect to find both static and fatigue strength to be important design considerations, since a single shaft may be subjected to static stresses, completely reversed, and repeated stresses, all acting at the same time.covers numerous variations, such as axles and spindles.The word “shaft”　Anaxle is a shaft, wither stationary or rotating, nor subjected to torsion load. A shirt rotating shaft is often called a spindle.arings, This reduces the bending moment, and hence the deflection and bending stress.Because of the similarity of their functions, clutches and brakes are treated together. In a simplified dynamic representation of a friction clutch, or brake, two inertias I1 and I2 traveling at the respective angular velocities W1 and W2, one of which may be zero in the case of brake, are to be brought to the same speed by engaging the clutch or brake. Slippage occurs because the two elements are running at different speeds and energy is dissipated during actuation, resulting in a temperature rise. In analyzing the performance of these devices we shall be interested in the actuating force, the torque transmitted, the energy loss and the temperature rise. The torque transmitted is related to the actuating force, the coefficient of friction, and the geometry of the clutch or brake. This is problem in static, which will have to be studied separately for eath geometric configuration. However, temperature rise is related to energy loss and can be studied without regard to the type of brake or clutch because the geometry of interest is the heat-dissipating surfaces. The various types of clutches and brakes may be classified as fllows:1. Rim type with internally expanding shoes2. Rim type with externally contracting shoes3. Band type4. Disk or axial type5. Cone type6. Miscellaneous typeThe analysis of all type of friction clutches and brakes use the same general procedure. The following step are necessary:1. Assume or determine the distribution of pressure on the frictional surfaces.2. Find a relation between the maximum pressure and the pressure at any point3. Apply the condition of statical equilibrium to find (a) the actuating force, (b) the torque, and (c) the support reactions.Miscellaneous clutches include several types, such as the positive-contact clutches, overload-release clutches, overrunning clutches, magnetic fluid clutches, and others.Introduciton of MachiningHave a shape as a processing method, all machining process for the production of the most commonly used and most important method. Machining process is a process generated shape, in this process, Drivers device on the workpiece material to be in the form of chip removal. Although in some occasions, the workpiece under no circumstances, the use of mobile equipment to the processing, However, the majority of the machining is not only supporting the workpiece also supporting tools and equipment to complete.Machining know the process has two aspects. Small group of low-cost production. For casting, forging and machining pressure, every production of a specific shape of the workpiece, even a spare parts, almost have to spend the high cost of processing. Welding to rely on the shape of the structure, to a large extent,depend on effective in the form of raw materials. In general, through the use of expensive equipment and without special processing conditions, can be almost any type of raw materials, mechanical processing to convert the raw materials processed into the arbitrary shape of the structure, as long as the external dimensions large enough, it is possible. Because of a production of spare parts, even when the parts and structure of the production batch sizes are suitable for the original casting, Forging or pressure processing to produce, but usually prefer machining.Strict precision and good surface finish, Machining the second purpose is the establishment of the high precision and surface finish possible on the basis of. Many parts, if any other means of production belonging to the large-scale production, Well Machining is a low-tolerance and can meet the requirements of small batch production. Besides, many parts on the production and processing of coarse process to improve its general shape of the surface. It is only necessary precision and choose only the surface machining. For instance, thread, in addition to mechanical processing, almost no other processing method for processing. Another example is the blacksmith pieces keyhole processing, as well as training to be conducted immediately after the mechanical completion of the processing. Primary Cutting ParametersCutting the work piece and tool based on the basic relationship between the following four elements to fully describe : the tool geometry, cutting speed, feed rate, depth and penetration of a cutting tool.Cutting Tools must be of a suitable material to manufacture, it must be strong, tough, hard and wear-resistant. Tool geometry -- to the tip plane and cutter angle characteristics -- for each cutting process must be correct.Cutting speed is the cutting edge of work piece surface rate, it is inches per minute to show. In order to effectively processing, and cutting speed must adapt to the level of specific parts -- with knives. Generally, the more hard work piece material, the lower the rate.Progressive Tool to speed iscut into the work piece speed. If the work piece or tool for rotating movement, feed rate per round over the number of inches to the measurement. When the work piece or tool for reciprocating movement and feed rate on each trip through the measurement of inches. Generally, in other conditions, feed rate and cutting speed is inversely proportional to。

机械毕业设计英文外文翻译对降低齿轮传动装载和卸载时因误差引起的噪音的研Title: Research on Reducing Noise Caused by Error in Gear Transmission during Loading and UnloadingAbstract:1. IntroductionGear transmission plays a crucial role in various mechanical systems, including automotive vehicles, industrial machinery, and power plants. However, the noise generated during gear transmission can be undesirable, affecting the performance and overall user experience. It is essential to develop techniquesto reduce gear transmission noise, especially during loading and unloading, where errors are more likely to occur.2. Sources of Noise in Gear TransmissionThe noise in gear transmission can be attributed to several factors, including meshing of gear teeth, friction, vibration, and structural resonances. These sources of noise contribute to a significant extent to the overall noise generated during gear transmission.3. Factors Leading to Transmission ErrorsTransmission errors refer to the discrepancy between the ideal motion and the actual motion of gear teeth during meshing.These errors can be caused by various factors, including manufacturing tolerances, misalignment of gears, wear, and temperature variations. It is essential to identify thesefactors that lead to transmission errors in order to implement effective noise reduction strategies.4. Strategies for Reducing Gear Transmission Noise4.1 Optimization of Gear Design: By improving the gear profile and tooth surfaces, the contact ratio between gears can be increased, reducing the impact of errors and subsequently reducing noise.4.2 Design of Noise-Reducing Gear Structures: Incorporating noise-reducing mechanisms, such as noise-absorbing materials, elastomeric coatings, and gear damping structures, can help minimize noise generated during transmission.4.3 Active Noise Control: Utilizing active noise control techniques, such as adaptive filtering and noise cancellation, can effectively reduce gear transmission noise.4.4 Lubrication and Surface Treatment: Proper lubrication and surface treatment can reduce friction and wear, which contribute to noise generation during gear transmission.4.5 Improvement of Manufacturing Processes: By enhancing the precision and accuracy of gear manufacturing processes, theoccurrence of transmission errors can be minimized, leading to reduced noise.5. Experimental Validation6. ConclusionImplementing effective strategies to reduce gear transmission noise during loading and unloading is essential for improving the overall performance and user experience of mechanical systems. By considering the sources of noise and factors leading to transmission errors, various approaches can be employed to minimize noise and enhance the efficiency of gear transmissions. The experimental validation will provideinsightful data on the effectiveness of the proposed strategies.。

二○一三届毕业论文外文翻译学院：工程机械学院专业：机械设计制造及其自动化姓名：贾孝峰学号：2504090903指导教师：赵悟完成时间：2013年 3 月27 日机械科学与技术杂志24（2010）29~32/content/1738-494xDOI 10.2007/S12206-009-1134-5研究行星齿轮系中空心太阳齿轮的弯曲应力Kyung-Eun Ko*,Do-Hyeong Lim, Pan-Yong Kim and Jinsoo Park 机械设计研究部门，韩国现代重工集团有限公司，韩国蔚山，682-792，Korea（原稿于2009年5月2日接收；于2009年9月21日修订；于2009年三11月16日发表）摘要一般来说，行走式行星齿轮减速齿轮是由多重行星齿轮阶段组成，并且在齿轮减速器末级有空心太阳齿轮。

在设计减速器齿轮中，准确估计太阳齿轮的牙齿根处的弯曲应力非常重要，因为太阳齿轮是减速器系统中的薄弱环节。

虽然使用标准齿轮代码可以轻易计算弯曲应力,比如美国设备制造商协会(AGMA)和国际标准化组织(ISO)6336系列几乎所有的齿轮，但是精确计算需要空心太阳齿轮有低备份比率(轮缘厚度除以轮齿高度)和相对大的根圆角半径。

在这项研究中,应用一个有限元分析(FEA)研究轮缘厚度和根圆角半径对空心太阳齿轮齿根弯曲应力的影响。

在标准规范下，牙齿根处弯曲应力的线性计算的常数坡备份比低于1.2。

然而，在行星齿轮系统中，轮缘处弯曲应力的影响则更为复杂。

同时比较了在各种备份比和根圆角半径下应用FEA计算弯曲应力和应用标准规定计算弯曲应力。

关键字：AGMA；备份比率；弯曲应力；齿根圆角半径；空心太阳齿轮；ISO；齿缘厚度1、引导语由于在密实度、同轴设计和高性能方面的优点，行星齿轮传动系统在机械行业普遍使用，特别是在汽车和航空航天应用上。

履带式挖掘机配备是一个由多个行星齿轮阶段组成的行星齿轮减速器。

行星齿轮传动系统的最后，行星齿轮减速器有一个空心太阳齿轮，由于其本身低备份比率（齿缘除以齿高）及较大的齿弯曲应力，这通常是系统中最弱的组件。

20外⽂⽂献翻译原⽂及译⽂参考样式华北电⼒⼤学科技学院毕业设计（论⽂）附件外⽂⽂献翻译学号： 0819******** 姓名：宗鹏程所在系别：机械⼯程及⾃动化专业班级：机械08K1指导教师：张超原⽂标题：Development of a High-PerformanceMagnetic Gear年⽉⽇⾼性能磁齿轮的发展1摘要：本⽂提出了⼀个⾼性能永磁齿轮的计算和测量结果。

上述分析的永磁齿轮有5.5的传动⽐，并能够提供27 Nm的⼒矩。

分析表明，由于它的弹簧扭转常数很⼩，因此需要特别重视安装了这种⾼性能永磁齿轮的系统。

上述分析的齿轮也已经被应⽤在实际中，以验证、预测其效率。

经测量，由于较⼤端齿轮传动引起的磁⼒齿轮的扭矩只有16 Nm。

⼀项关于磁齿轮效率损失的系统研究也展⽰了为什么实际⼯作效率只有81％。

⼀⼤部分磁损耗起源于轴承，因为机械故障的存在，此轴承的备⽤轴承在此时是必要的。

如果没有源于轴的少量磁泄漏，我们估计能得到⾼达96％的效率。

与传统的机械齿轮的⽐较表明，磁性齿轮具有更好的效率和单位体积较⼤扭矩。

最后，可以得出结论，本⽂的研究结果可能有助于促进传统机械齿轮向磁性齿轮发展。

关键词：有限元分析（FEA）、变速箱，⾼转矩密度，磁性齿轮。

⼀、导⾔由于永久磁铁能产⽣磁通和磁⼒，虽然⼏个世纪过去了，许多⼈仍然着迷于永久磁铁。

，在过去20年的复兴阶段，正是这些优点已经使得永久磁铁在很多实际中⼴泛的应⽤，包括在起重机，扬声器，接头领域，尤其是在永久磁铁电机⽅⾯。

其中对永磁铁的复兴最常见于效率和转矩密度由于永磁铁的应⽤显著提⾼的⼩型机器的领域。

在永久磁铁没有获取⾼度重视的⼀个领域是传动装置的领域，也就是说，磁⼒联轴器不被⼴泛⽤于传动装置。

磁性联轴器基本上可以被视为以传动⽐为1：1磁⼒齿轮。

相⽐标准电⽓机器有约10kN m/m的扭矩，装有⾼能量永久磁铁的磁耦有⾮常⾼的单位体积密度的扭矩，变化范围⼤约300–400 kN 。

行星齿轮中英文对照外文翻译文献（文档含英文原文和中文翻译）原文:Planetary GearsIn troduct ionThe Tamiya pla netary gearbox is drive n by a small DC motor that runs at about 10,500 rpm on 3.0V DC and draws about 1.0A. The maximum speed ratio is 1:400, givi ng an output speed of about 26 rpm. Four pla netary stages are supplied with the gearbox, two 1:4 and two 1:5, and any comb in ati on can be selected. Not only is this a good drive for small mechanical applications, it provides an excellent review of epicycle gear trains. The gearbox is a very well-desig ned plastic kit that can be assembled in about an hour with very few tools. The source for the kit is give n in the Refere nces.Let's beg in by review ing the fun dame ntals of geari ng, and the trick of an alyz ing epicyclic gear trains.Epicyclic Gear TrainsA pair of spur gears is represented in the diagram by their pitch circles , which are tangent at the pitch point P. The meshing gear teeth extend beyond the pitch circle by the addendum, and the spaces between them have a depth ben eath the pitch circle by the dede ndum. If the radii of the pitch circles are a and b, the dista nee betwee n the gear shafts is a + b. In the action of the gears, the pitch circles roll on one ano ther without slipp ing. To en sure this, the gear teeth must have a proper shape so that whe n the driv ing gear moves uniformly, so does the driven gear. This means that the line of pressure, normal to the tooth profiles in con tact, passes through the pitch point. Then, the tran smissi on of power will be free of vibrati on and high speeds are possible. We won't talk further about gear teeth here, havi ng stated this fun dame ntal prin ciple of geari ng.If a gear of pitch radius a has N teeth, the n the dista nee betwee n corresp onding points on successive teeth will be 2 n a/N, atyqtx a lntid the circular pitch . If two gears are to mate, the circular pitches must be the same. The pitch is usually stated as the rati on 2a/N, called the diametral pitch . If you count the number of teeth on a gear, then the pitch diameter is the number of teeth times the diametral pitch. If you know the pitch diameters of two gears, the n you can specify the dista nee betwee n the shafts.The velocity ratio r of a pair of gears is the ratio of the angular velocity of the driven gear to the angular velocity of the driving gear. By the condition of rolling of pitch circles, r = -a/b = -N 1/N2, since pitch radii are proportional to the number of teeth. The angular velocity n of the gears may be given in radians/sec, revoluti ons per minute (rpm), or any similar un its. If we take one direct ion of rotati on as positive, the n the other direct ion is n egative. This is the reas on for the (-) sig n in the above expressi on. If one of the gears is internal (having teeth on its inner rim), then the velocity ratio is positive, since the gears will rotate in the same direct ion.The usual in volute gears have a tooth shape that is tolera nt of variati ons in the dista nce betwee n the axes, so the gears will run smoothly if this dista nce is not quite correct. The velocity ratio of the gears does not depe nd on the exact spac ing of the axes, but is fixed by the nu mber of teeth, or what is the same thi ng,by the pitch diameters. Slightly increasing the distanee above its theoretical value makes the gears run easier, since the cleara nces are larger. On the other hand, backlash is also in creased, which may not be desired in some applicati ons.An epicyclic gear train has gear shafts mounted on a moving arm or carrier that can rotate about the axis, as well as the gears themselves. The arm can be an in put eleme nt, or an output eleme nt, and can be held fixed or allowed to rotate. The outer gear is the ring gear or annu lus. A simple but very com mon epicyclic train is the sun-and-planet epicyclic train, shown in the figure at the left. Three planetary gears are used for mechanical reasons; they may be considered as one in describing the action of the gearing. The sun gear, the arm, or the ring gear may be in put or output lin ks.If the arm is fixed, so that it cannot rotate, we have a simple train of three gears. Then, n 2M1 = -N1/N2,n3/n2 = +N 2/N3, and n/n1 = -N 1/N3. This is very simple, and should not be confusing. If the arm is allowed to move, figuring out the velocity ratios taxes the human intellect. Attempting this will show the truth of the stateme nt; if you can man age it, you deserve praise and fame. It is by no means impossible, just in voved. However, there is a very easy way to get the desired result. First, just con sider the gear train locked, so it moves as a rigid body, arm and all. All three gears and the arm then have a unity velocity ratio. The trick is that any motion of the gear train can carried out by first holding the arm fixed and rotating the gears relative to one another, and then locking the train and rotating it about the fixed axis. The net motion is the sum or difference of multiples of the two separate motions that satisfies the conditions of the problem (usually that one eleme nt is held fixed). To carry out this program, con struct a table in which the an gular velocities of the gears and arm are listed for each, for each of the two cases. The locked train gives 1, 1, 1, 1 for arm, gear 1, gear 2 and gear 3. Arm fixed gives 0, 1, -N 1/N2, -N1/N3. Suppose we want the velocity rati on betwee n the arm and gear 1, whe n gear 3 is fixed. Multiply the first row by a con sta nt so that whe n it is added to the sec ond row, the velocity of gear 3 will be zero. This con sta nt is N 1/N3. Now, doing one displaceme nt and the n the other corresp onds to addi ng the two rows. We find N 1/N3, 1 + N 1/N3, N1/N3 - N1/N2.The first nu mber is the arm velocity, the sec ond the velocity of gear 1, so the velocity ratio betwee n them is N〃(N1 + N3), after multiplying through by N 3. This is the velocity ratio we need for the Tamiya gearbox, where the ring gear does not rotate, the sun gear is the in put, and the arm is the output. The procedure is general, however, and will work for any epicyclic train.One of the Tamiya planetary gear assemblies has N1 = N2 = 16, N3 = 48, while the other has N 1 = 12, N2 = 18, N 3 = 48. Because the planetary gears must fit between the sun and ring gears, the condition N 3 = N1 + 2N2 must be satisfied. It is in deed satisfied for the nu mbers of teeth give n. The velocity ratio of the first set will be 16/(48 + 16) = 1/4. The velocity ratio of the seco nd set will be 12/(48 + 12) = 1/5. Both ratios are as advertised. Note that the sun gear and arm will rotate in the same directi on.The best gen eral method for solvi ng epicyclic gear trains is the tabular method, since it does not contain hidden assumptions like formulas, nor require the work of the vector method. The first step is to isolate the epicyclic train, separat ing the gear trains for in puts and outputs from it. Find the in put speeds or turns, using the in put gear trains. There are, in gen eral, two in puts, one of which may be zero in simple problems. Now prepare two rows of the table of turns or angular velocities. The first row corresponds to rotating around the epicyclic axis once, and consists of all 1's. Write down the second row assuming that the arm velocity is zero, using the known gear ratios. The row that you want is a lin ear comb in ati on of these two rows, with unknown multipliers x and y. Summing the en tries for the in put gears gives two simulta neous lin ear equatio ns for x and y in terms of the known in put velocities. Now the sum of the two rows multiplied by their respective multipliers gives the speeds of all the gears of in terest. Fin ally, find the output speed withthe aid of the output gear train. Be careful to get the directi ons of rotatio n correct, with respect to a direct ion take n as positive.The Tamiya Gearbox KitThe parts are best cut from the sprues with a flush-cutter of the type used in electr onics. The very small bits of plastic remaining can then be removed with a sharp X-acto knife. Carefully remove all excess plastic, as the in struct ions say.Read the in struct ions carefully and make sure that things are the right way up and in the correct relative posit ons. The gearbox un its go together easily with light pressure. Note that the brow n ones must go together in the correct relative orientation. The 4mm washers are the ones of which two are supplied, and there is also a full-size draw ing of one in the in structi ons. The smaller washers will not fit over the shaft, any way. The output shaft is metal. Use larger long-nose pliers to press the E-ring into positi on in its groove in front of the washer. There is a picture show ing how to do this. There was an extra E-ri ng in my kit. The three prongs fit into the carriers for the pla netary gears, and are drive n by them.Now stack up the gearbox un its as desired. I used all four, being sure to put a 1:5 unit on the end n ext to the motor. Therefore, I n eeded the long screws. Press the orange sun gear for the last 1:5 un it firmly on the motor shaft as far as it will go. If it is not well-seated, the motor clip will not close. It might be a good idea to put some lubricant on this gear from the tube included with the kit. If you use a different lubricant, test it first on a piece of plastic from the kit to make sure that it is compatible. A dry graphite lubricant would also work quite well. This should spread lubrica nt on all parts of the last un it, which is the one subject to the highest speeds. Put the motor in place, gently but firmly, wiggling it so that the sun gear meshes. If the sun gear is not meshed, the motor clip will not close. Now put the motor term in als in a vertical column, and press on the motor clamp.The reverse of the in struct ions show how to attach the drive arm and gives some hints on use of the gearbox. I got an extra spri ng pin, and two extra 3 mm washers. If you have some small washers, they can be used on the mach ine screws holdi ng the gearbox together. Eno ugh torque is produced at the output to damage things (up to 6 kg-cm), so make sure the output arm can rotate freely. I used a sta ndard laboratory DC supply with variable voltage and current limiting, but dry cells could be used as well. The current drain of 1 A is high even for D cells, so a power supply is in dicated for serious use. The in structi ons say not to exceed 4.5V, which is good advice. With 400:1 reduction, the motor should run freely whatever the output load.My gearbox ran well the first time it was tested. I timed the output revolutions with a stopwatch, and found 47s for 20 revolutions, or 25.5 rpm. This corresponds to 10,200 rpm at the motor, which is close to specifications. It would be easy to connect another gearbox in series with this one (parts are included to make this possible), and get about 4 revolutions per hour. Still another gearbox would produce about one revolution in four days. This is an excellent kit, and I recommend it highly.Other Epicyclic Trai nsA very famous epicyclic cha in is the Watt sun-an d-pla net gear, pate nted in 1781 as an alter native to the crank for converting the reciprocati ng motio n of a steam engine into rotary moti on .It was inven ted by William Murdoch. The crank, at that time, had bee n pate nted and Watt did not want to pay royalties. An in cide ntal adva ntage was a 1:2 in crease in the rotative speed of the output. However, it was more expe nsive than a crank, and was seldom used after the crank pate nt expired. Watch the ani mati on on Wikipedia.The in put is the arm, which carries the pla net gear wheel mat ing with the sun gear wheel of equal size. The planet wheel is prevented from rotating by being fastened to the connecting rod. It oscillates a little, but always retur ns to the same place on every revoluti on. Using the tabular method expla ined above, the firstline is 1, 1, 1 where the first number refers to the arm, the second to the planet gear, and the third to the sun gear. The sec ond line is 0, -1, 1, where we have rotated the pla net one tur n an ticlockwise. Addi ng, we get 1,0, 2, which means that one revolution of the arm (one double stroke of the engine) gives two revolutions of the sun gear.We can use the sun-and-planet gear to illustrate another method for analyzing epicyclical trains in which we use velocities. This method may be more satisfying than the tabular method and show more clearly how the train works. In the diagram at the right, A and O are the cen tres of the pla net and sun gears, respectively. A rotates about O with an gular velocity 1, which we assum e clockwise. At the positi onshow n, this gives A a v elocity 2 1 upward, as show n. Now the pla net gear does not rotate, so all points in it move with the same velocity as A. This in cludes the pitch point P, which is also a point in the sun gear, which rotates about the fixed axis O with an gular velocity 2. Therefore, 2 =2 <ej, the same result as with the tabular method.The diagram at the left shows how the velocity method is applied to the pla netary gear set treated above. The sun and pla net gears are assumed to be the same diameter (2 un its). The ring gear is the n of diameter 6. Let us assume the sun gear is fixed, so that the pitch point P is also fixed. The velocity of point A is twice the angular velocity of the arm. Since P is fixed, P' must move at twice the velocity of A, or four times the velocity of the arm. However, the velocity of P' is three times the angular velocity of the ring gear as well, so that 3 r = 4 ee If the arm is the in put, the velocity ratio is the n 3:4, while if the ring is the in put, the velocity ratio is 4:3.A three-speed bicycle hub may contain two of these epicyclical trai ns, with the ring gears conn ected (actually, com mon to the two trai ns). The in put from the rear sprocket is to the arm of one train, while the output to the hub is from the arm of the sec ond train .It is possible to lock one or both of the sun gears to the axle, or else to lock the sun gear to the arm and free of the axle, so that the train gives a 1:1 ratio. The three gears are: high, 3:4, output train locked; middle, 1:1, both trains locked, and low, 4:3 in put train locked. Of course, this is just one possibility, and many differe nt variable hubs have bee n manu factured. The pla netary variable hub was in troduced by Sturmey-Archer in 1903. The popular AW hub had the ratios men ti oned here.Chain hoists may use epicyclical trains. The ring gear is stati on ary, part of the main hous ing. The in put is to the sun gear, the output from the pla net carrier. The sun and pla net gears have very differe nt diameters, to obta in a large reducti on ratio.The Model T Ford (1908-1927) used a reverted epicyclic transmission in which brake bands applied to the shafts carrying sun gears selected the gear ratio. The low gear ratio was 11:4 forward, while the reverse gear ratio was -4:1. The high gear was 1:1. Reverted means that the gears on the planet carrier shaft drove other gears on shafts concentric with the main shaft, where the brake bands were applied. The floor controls were three pedals: low-n eutral-high, reverse, tran smissi on brake. The hand brake applied stopped the left-hand pedal at neutral. The spark advance and throttle were on the steering column.The automotive differe ntial, illustrated at the right, is a bevel-gear epicyclic train. The pinion drives the ring gear (crow n wheel) which rotates freely, carry ing the idler gears. Only one idler is n ecessary, but more than one gives better symmetry. The ring gear corresponds to the planet carrier, and the idler gears to the pla net gears, of the usual epicyclic cha in. The idler gears drive the side gears on the half-axles, which correspond to the sun and ring gears, and are the output gears. When the two half-axles revolve at the same speed, the idlers do not revolve. When the half-axles move at different speeds, the idlers revolve. The differential applies equal torque to the side gears (they are driven at equal distances by the idlers) while allowing them to rotate at differe nt speeds. If one wheel slips, it rotates at double speed while the other wheel does not rotate. The same (small) torque is, n evertheless, applied to both wheels.The tabular method is easily used to an alyze the an gular velocities. Rotat ing the cha in as a whole gives 1,0, 1, 1 for ring, idler, left and right side gears. Holding the ring fixed gives 0, 1, 1, -1. If the right side gear is held fixed and the ring makes one rotation, we simply add to get 1, 1,2, 0, which says that the left side gear makes two revolutions. The velocity method can also be used, of course. Considering the (equal) forces exerted on the side gears by the idler gears shows that the torques will be equal.Refere ncesTamiya Planetary Gearbox Set, Item 72001-1400. Edmund Scientific, Catalog No. C029D, item D30524-08 ($19.95).C. Carmichael, ed., Kent's Mechanical Engineer's Handbook , 12th ed. (New York: John Wiley and Sons, 1950). Design and Production Volume, p.14-49 to 14-43.V. L. Doughtie, Eleme nts of Mecha nism, 6th ed. (New York: John Wiley and So ns, 1947). pp. 299-311. Epicyclic gear. Wikipedia article on epicyclic trains.Sun and planet gear. Includes an animation.行星齿轮机构简介Tamiya行星轮变速箱由一个约10500 r/min,3.0V , 1.0A的直流电机运行。