外文翻译--齿轮和齿轮传动
毕业设计外文翻译齿轮
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。
中英文齿轮基本术语
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齿面Tooth flank右侧齿面Right flank左侧齿面Left flank同侧齿面Corresponding flank异侧齿面Opposite flank工作齿面Working flank非工作齿面Non-working flank相啮齿面Mating flank共轭齿面Conjugate flank可用齿面Usable flank有效齿面Active flank上齿面Addendum flank下齿面Dedendum flank齿根过渡曲面Fillet齿顶Crest；Top land槽底Bottom land齿廓Tooth profile端面齿廓Transverse profile法向齿廓Normal profile轴向齿廓Axial profile背锥齿廓Back cone tooth profile齿线Tooth trace齿棱Tip；Tooth tip模数Module端面模数Transverse module法向模数Normal module轴向模数Axial module径节Diametral pitch齿数Number of teech当量齿数Virtual number of teeth头数Number of starts；Number of threads螺旋线Helix；Circular helix圆锥螺旋线Conical spiral螺旋角Helix angle；Spiral angle导程Lead导程角Lead angle阿基米德螺旋线Archimedes spiral外摆线Epicycloid长幅外摆线Prolate epoicycloid短幅外摆线Curtate epoicycloid摆线Cycloid长幅摆线Prolate cycloid短幅摆线Curtate cycloid内摆线Hypocycloid直齿轮Spur gear斜齿轮Helical gear；Single-helical gear直齿条Spur rack斜齿条Helical rack人字齿轮Double-helical gear渐开线齿轮Involute cylindrical gear摆线齿轮Cycloidal gear圆弧齿轮Circular-arc gear；W-N gear双圆弧齿轮Double-circular-arc gear假想曲面Imaginary surfance任意点法向压力角Normal pressure angle at a point 任意点端面压力角Transverse pressure angle at a point 啮合角Working pressure angle顶隙Bottom clearance圆周侧隙Circumferential blacklash法向侧隙Normal blacklash径向侧隙Radial blacklash锥齿轮Bevel gear锥齿轮副Bevel gear pair准双曲面齿轮副Hypoid gear pair准双曲面齿轮Hypoid gear冠轮Crown gear端面齿轮Contrate gear直齿锥齿轮Straight bevel gear斜齿锥齿轮Skew bevel gear；Helical bevel gear曲面齿锥齿轮Curved tooth bevel gear弧齿锥齿轮Spiral bevel gear摆线齿锥齿轮Enicycloid bevel gear零度齿锥齿轮Zerot bevel gear圆柱齿轮端面齿轮副Contrate gear pair锥齿轮的当量圆柱齿轮Virtual cylindrical gear of bevel gear8字啮合锥齿轮Octoid gear圆柱齿弧锥齿轮Spiral bevel gear with circle arc tooth profile分度圆锥面Reference cone节圆锥面Pitch cone齿顶圆锥面Face cone；tip cone齿根圆锥面Root cone背锥面Back cone前锥面Front cone中锥面Middle cone分锥顶点Reference cone apex轴线交点Crossing point of axes公共锥顶Common apex齿根圆环面Root tosoid咽喉面Gorge喉平面Gorge plane喉圆Gorge circle分度圆蜗旋线Reference helix螺纹Thread蜗杆齿宽Worm facewidth蜗轮齿宽Worm wheel facewidth直径系数Diametral quotient咽喉半径Gorge radius齿宽角Width angle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 tosoid模具成形不良用语英汉对照aberration 色差bite 咬入blacking hole 涂料孔(铸疵) blacking scab 涂料疤blister 起泡blooming 起霜blow hole 破孔blushing 泛白body wrinkle 侧壁皱纹breaking-in 冒口带肉bubble 膜泡burn mark 糊斑burr 毛边camber 翘曲cell 气泡center buckle 表面中部波皱check 细裂痕checking 龟裂chipping 修整表面缺陷clamp-off 铸件凹痕collapse 塌陷color mottle 色斑corrosion 腐蚀crack 裂痕crazing 碎裂crazing 龟裂deformation 变形edge 切边碎片edge crack 裂边fading 退色filler speak 填充料斑fissure 裂纹flange wrinkle 凸缘起皱flaw 刮伤flow mark 流痕galling 毛边glazing 光滑gloss 光泽grease pits 污斑grinding defect 磨痕haircrack 发裂haze 雾度incrustation 水锈indentation 压痕internal porosity 内部气孔mismatch 偏模mottle 斑点necking 缩颈nick 割痕orange peel 橘皮状表面缺陷overflow 溢流peeling 剥离pit 坑pitting corrosion 点状腐蚀plate mark 模板印痕pock 麻点pock mark 痘斑resin streak 树脂流纹resin wear 树脂脱落riding 凹陷sagging 松垂saponification 皂化scar 疤痕scrap 废料scrap jam 废料阻塞scratch 刮伤/划痕scuffing 深冲表面划伤seam 裂痕shock line 模口挤痕short shot 充填不足shrinkage pool 凹孔sink mark 凹痕skin inclusion 表皮折叠straightening 矫直streak 条状痕surface check 表面裂痕surface roughening 橘皮状表皮皱折surging 波动sweat out 冒汗torsion 扭曲warpage 翘曲waviness 波痕webbing 熔塌weld mark 焊痕whitening 白化wrinkle 皱纹实验与试验用语air permeability test 透气性试验austenitic steel 沃斯田铁钢brinell hardness 布耐内尔硬度brinell hardness test 布氏硬度试验charpy impact test 夏比冲击试验conical cup test 圆锥杯突试验cup flow test 杯模式流动度试验dart drop impact test 落锤冲击试验Elmendorf test 埃罗门多撕裂强度试验environmental stress cracking test环境应力龟裂试验ericessen test 埃留伸薄板拉伸试验falling ball impact test 落球冲击试验fatigue test 疲劳试验ferrite 纯铁体gantt chart 甘特图heat cycle test 热循环试验histogram 柱状图hot bend test 热弯试验izod impact test 埃左德冲击试验loop tenacity 环结强度martens heat distortion temperature test 马顿斯耐热试验martensite 马氏体mullen bursting strength tester 密廉式破裂强度试验机nol ring test 诺尔环试验normal distribution 常态分配ozone resistance test 抗臭氧试验pareto diagram 柏拉图peeling test 剥离试验pinhole test 针孔试验机rattler test 磨耗试验rockweel hardness test 洛氏硬度试验rockweel hardness 洛氏威尔硬度rolinx process 罗林克斯射出压缩成形法rossi-peakes flow test 罗西皮克斯流动试验sampling inspection 抽样检查scratch hardness 抗刮硬度shore hardness 萧氏硬度spiral flow test 螺旋流动试验surface abrasion test 表面磨耗试验taber abraser 泰伯磨耗试验机tensile impact test 拉伸冲击试验tensile strength 抗拉强度tension test 张力试验thermal shock test 冷热剧变试验torsion test 扭曲试验ubbelohde viscometer 乌别洛德黏度计vicat indentation test 维卡针压陷试验Vickers hardness test 维氏硬度试验warpage test 翘曲试验weatherometer 人工老化试验机weissenberg effect 威森伯格回转效应锻铸造关连用语accretion 炉瘤acid converter 酸性转炉acid lining cupola 酸性熔铁炉acid open-hearth furnace 酸性平炉aerator 松砂机air set mold 常温自硬铸模airless blasting cleaning 离心喷光all core molding 集合式铸模all round die holder 通用模座assembly mark 铸造合模记号back pouring 补浇注backing sand 背砂base bullion 粗金属锭base permeability 原砂透气度belling 压凸billet 坏料bleed 漏铸blocker 预锻模膛blocking 粗胚锻件blow hole 铸件气孔board drop hammer 板落锤bottom pour mold 底浇bottom pouring 底注boxless mold 脱箱砂模break-off core 缩颈砂心brick molding 砌箱造模法buckle 剥砂面camber 错箱camlachie cramp 铸包cast blade 铸造叶片casting flange 铸造凸缘casting on flat 水平铸造chamotte sand 烧磨砂charging hopper 加料漏斗cleaning of casting 铸件清理closed-die forging 合模锻造core compound 砂心黏结剂core template 砂心模板core vent 砂蕊排气孔corner gate 压边浇口counter blow hammer 对击锻造counter lock 止口镶嵌方式depression 外缩凹孔die approach 模口角度draw out 锻造拔长draw plate 起模板draw spike 起模长针dummying 预锻embedded core 加装砂心erosion 冲砂fettling 铸件清理filling core 埋入砂心~filling in 填砂film play 液面花纹finishing slag 炼后熔渣flash gutter 锻模飞边槽flask molding 砂箱造模forging roll 辊锻机formboard 进模口板gutter 锻模飞边槽hammer man 锻工heading machine 顶镦机impacter 卧式锻造机inblock cast 整体铸造ingot 铸锭ingot blank 铸坯inlay casting 镶铸法investment casting 失模铸造isothermal forging 恒温锻造loose piece 木模活块molding pit 铸模地坑pouring process 浇注法recasting 重铸roll forging 轧锻rolled surface 轧制表面rough sand 粗砂roughing forge 粗锻sand crushing 塌箱seamless forging 无缝锻造separate 分离shave 崩砂shrinkage fit 收缩配合shut height 闭合高度sieve mesh 筛孔sintering of sand 铸砂烧贴slag 熔渣slag inclusion 夹渣stickness 黏模性strip layout 带状胚料排样法tap casting 顶注top gate 顶注浇口unworked casting 不加工铸件upender 翻转装置upending 顶锻uphill casting 底铸white cast iron 白口铸件品质、生产名称类QC quality control 品质管理人员FQC final quality control 终点品质管制人员IPQC in process quality control 制程中的品质管制人员OQC output quality control 最终出货品质管制人员IQC incoming quality control 进料品质管制人员TQC total quality control 全面质量管理POC passage quality control 段检人员QA quality assurance 质量保证人员OQA output quality assurance 出货质量保证人员QE quality engineering 品质工程人员品质保证类：FAI first article inspection 新品首件检查FAA first article assurance 首件确认TVR tool verification report 模具确认报告3B 3B 模具正式投产前确认CP capability index 能力指数CPK capability index of process 模具制程能力参数SSQA standardized supplier quality 合格供应商品质评估OOBA out of box audit 开箱检查QFD quality function deployment 品质机能展开FMEA failure model effectiveness analysis 失效模式分析8 disciplines 8项回复内容FA final audit 最后一次稽核CAR corrective action request 改正行动要求corrective action report 改正行动报告（注：本资料素材和资料部分来自网络，仅供参考。
机械零件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)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)。
外文翻译-齿轮机构
翻译部分英文原文Gear mechanismsGear mechanisms are used for transmitting motion and power from one shaft to another by means of the positive contact of successively engaging teeth. In about 2,600B.C., Chinese are known to have used a chariot incorporating a complex series of gears like those illustrated in Fig.2.7. Aristotle, in the fourth century B .C .wrote of gears as if they were commonplace. In the fifteenth century A.D., Leonardo da Vinci designed a multitude of devices incorporating many kinds of gears. In comparison with belt and chain drives ,gear drives are more compact ,can operate at high speeds, and can be used where precise timing is desired. The transmission efficiency of gears is as high as 98 percent. On the other hand, gears are usually more costly and require more attention to lubrication, cleanliness, shaft alignment, etc., and usually operate in a closed case with provision for proper lubrication.Gear mechanisms can be divided into planar gear mechanisms and spatial gear mechanisms. Planar gear mechanisms are used to transmit motion and spatial gear mechanisms. Planar gear mechanisms are used to transmit motion and power between parallel shafts ,and spatial gear mechanisms between nonparallel shafts.Types of gears(1)Spur gears. The spur gear has a cylindrical pitch surface and has straight teeth parallel to its axis as shown in Fig. 2.8. They are used to transmit motion and power between parallel shafts. The tooth surfaces of spur gears contact on a straight line parallel to the axes of gears. This implies that tooth profiles go into and out of contact along the whole facewidth at the same time. This will therefore result in the sudden loading and sudden unloading on teeth as profiles go into and out of contact. As aresult, vibration and noise are produced.(2)Helical gears. These gears have their tooth elements at an angle or helix to the axis of the gear(Fig.2.9). The tooth surfaces of two engaging helical gears inn planar gear mechanisms contact on a straight line inclined to the axes of the gears. The length of the contact line changes gradually from zero to maximum and then from maximum to zero. The loading and unloading of the teeth become gradual and smooth. Helical gears may be used to transmit motion and power between parallel shafts[Fig.2.9(a)]or shafts at an angle to each other[Fig. 2.9(d)]. A herringbone gear [Fig. 2.9(c)] is equivalent to a right-hand and a left-hand helical gear placed side by side. Becauseof 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 around the gear for ease in machining.(3)Bevel gars. The teeth of a bevel gear are distributed on the frustum of a cone. The corresponding pitch cylinder in cylindrical gears becomes pitch cone. The dimensions of teeth on different transverse planes are different. For convenience, parameters and dimensions at the large end are taken to be standard values. Bevel gears are used to connect shafts which are not parallel to each other. Usually the shafts are 90 deg. to each other, but may be more or less than 90 deg. The two mating 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 tooth elements may be straight or spiral, so that we have plain and spiral bevel gears. Hypoid comes from the word hyperboloid and indicates the surface on which the tooth face lies. Hypoid gears are similar to bevel gears, but the two shafts do not intersect. The teeth are curved, and because of the nonintersection of the shafts, bearings can be placed on each side of each gear. The principal use of thid type of gear is in automobile rear ends for the purpose of lowering the drive shaft, and thus the car floor.(4)Worm and worm gears. Worm gear drives are used to transmit motion and ower between non-intersecting and non-parallel shafts, usually crossing at a right angle, especially where it is desired to obtain high gear reduction in a limited space. Worms are a kind of screw, usually right handed for convenience of cutting, or left handed it necessary. According to the enveloping type, worms can be divided into single and double enveloping. Worms are usually drivers to reduce the speed. If not self-locking, a worm gear can also be the driver in a so called back-driving mechanism to increase the speed. Two things characterize worm gearing (a) large velocity ratios, and (b) high sliding velocities. The latter means that heat generation and power transmission efficiency are of greater concern than with other types of gears.(5)Racks. 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 lathe rack and pinion is good example of this mechanism.Geometry of gear toothThe basic requirement of gear-tooth geometry is the provision of angular velocity rations that are exactly constant. Of course, manufacturing inaccuracies andtooth deflections well cause slight deviations in velocity ratio; but acceptable tooth profiles are based on theoretical curves that meet this criterion.The action of a pair of gear teeth satisfying this requirement is termed conjugate gear-tooth action, and is illustrated in Fig. 2.12. The basic law of conjugate gear-tooth action states that as the gears rotate, the common normal to the surfaces at the point of contact must always intersect the line of centers at the same point P called the pitch point.The law of conjugate gear-tooth can be satisfied by various tooth shapes, but the only one of current importance is the involute, or, more precisely, the involute of the circle. (Its last important competitor was the cycloidal shape, used in the gears of Model T Ford transmissions.) An involute (of the circle) is the curve generated by any point on a taut thread as it unwinds from a circle, called the base circle. The generation of two involutes is shown in Fig. 2.13. The dotted lines show how these could correspond to the outer portion of the right sides of adjacent gear teeth. Correspondingly, involutes generated by unwinding a thread wrapped counterclockwise around the base circle would for the outer portions of the left sides of the teeth. Note that at every point, the involute is perpendicular to the taut thread, since the involute is a circular arc with everincreasing radius, and a radius is always perpendicular to its circular arc. It is important to note that an involute can be developed as far as desired outside the base circle, but an involute cannot exist inside its base circle.Let us now develop a mating pair of involute gear teeth in three steps: friction drive, belt drive, and finally, involute gear-tooth drive. Figure 2.14 shows two pitch circles. Imagine that they represent two cylinders pressed together. If slippage does not occur, rotation of one cylinder (pitch circle) will cause rotation of the other at an angular velocity ratio inversely proportional to their diameters. In any pair of mating gears, the smaller of the two is called the pinion and the larger one the gear. (The term “gear” is used in a general sense to indicate either of the members, and also in a specific sense to indicate the larger of the two.) Using subscripts p and g to denote pinion and gear, respectively.In order to transmit more torque than is possible with friction drive alone, we now add a belt drive running between pulleys representing the base circles, as in Fig 2.15. If the pinion is turned counterclockwise a few degrees, the belt will cause the gear to rotate in accordance with correct velocity ratio. In gear parlance, an gle Φ is called the pressure angle. From similar triangles, the base circles have the same ratio as the pitch; thus, the velocity ratio provided by the friction and belt drives are the same.In Fig. 2.16 the belt is cut at point c, and the two ends are used to generate involute profiles de and fg for the pinion and gear, respectively. It should now be clear why Φ is called the pressure angle: neglecting sliding friction, the force of one involute tooth pushing against the other is always at an angle equal to the pressure angle. A comparison of Fig. 2.16 and Fig.2.12 shows that the involute profiles do indeed satisfy the fundamental law of conjugate gear-tooth action. Incidentally, the involute is the only geometric profile satisfying this law that maintains a constant pressure angle as the gears rotate. Note especially that conjugate involute action can take place only outside of both base circles.Nomenclature of spur gearThe nomenclature of spur gear (Fig .2.17) is mostly applicable to all other type of gears.The diameter of each of the original rolling cylinders of two mating gears is called the pitch diameter, and the cylinder’s sectional outline is called the pitch circle. The pitch circles are tangent to each other at pitch point. The circle from which the involute is generated is called the base circle. The circle where the tops of the teeth lie is called the dedendum circle. Similarly, the circle where the roots of the teeth lie is called the dedendum circle. Between the addendum circle and the dedendum circle, there is an important circle which is called the reference circle. Parameters on the reference circle are standardized. The module m of a gear is introduced on the reference circle as a basic parameter, which is defined as m=p/π. Sizes of the teeth and gear are proportional to the module m.The addendum is the radial distance from the reference circle to the addendum circle. The dedendum is the radial distance from the reference circle to the dedendum circle. Clearance is the difference between addendum and dedendum in mating gears. Clearance prevents binding caused by any possible eccentricity.The circular pitch p is the distance between corresponding side of neighboring teeth, measured along the reference circle. The base pitch is similar to the circular pitch is measured along the base circle instead of along the reference circle. It can easily be seen that the base radius equals the reference radius times the cosine of the pressure angle. Since, for a given angle, the ratio between any subtended arc and its radius is constant, it is also true that the base pitch equals the circular pitch times the cosine of the pressure angle. The pressure angle is the angle between the normal and the circumferential velocity of the point on a specific circle. The pressure angle on the reference circle is also standardized. It is most commonly 20º(sometimes 15º).The line of centers is a line passing through the centers of two mating gears. The center distance (measured along the line of centers) equals the sum of the pitchradii of pinion and gear.Tooth thickness is the width of the tooth, measured along the reference circle, is also referred to as tooth thickness. Width of space is the distance between facing side of adjacent teeth, measured along the reference circle. Tooth thickness plus width of space equals the circular pitch. Backlash is the width of space minus the tooth thickness. Face width measures tooth width in an axial direction.The face of the tooth is the active surface of the tooth outside the pitch cylinder. The flank of the tooth is the active surface inside the pitch cylinder. The fillet is the rounded corner at the base of the tooth. The working depth is the sum of the addendum of a gear and the addendum of its mating gear.In order to mate properly, gears running together must have: (a) the same module; (b) the same pressure angle; (c) the same addendum and dedendum. The last requirement is valid for standard gears only.Rolling-ContactbearingsThe rolling-contact bearing consists of niier and outer rings sepatated by a number of rolling elements in the form of balls ,which are held in separators or retainers, and roller bearings have mainly cyinndrical, conical , or barrelcage.The needles are retainde by integral flanges on the outer race,Bearigs with rolling contact have no skopstick effect,low statting torqeu and running friction,and unlike as in journal bearings. The coefficient of friction varies little with load or opeed.Probably the outstanding of a rolling-contant beating over a sliding bearing is its low statting friction.The srdinary sliding bearing starts from rest with practically metal to metal contact and has a high coefficient of friction as compared with that between rolling members.This teature is of particular important in the case of beatings whcch vust carry the same laode at test as when tunning,for example.less than one-thirtieth as much force is required to start a raliroad freight car equopped with roller beatings as with plain journal bearings.However.most journal bearing can only carry relatively light loads while starting and do not become heavily loaded until the speed is high enough for a hydrodynamic film to be built up.At this time the friction id that in the luvricant ,and in a properly designed journal bearing the viscous friction will be in the same order of magnitude ad that for a that for a rolling-conanct bearing.中文译文齿轮机构齿轮机构用来传递运动和动力，通过连续啮合轮齿的正确接触，从一根轴传动到另一根轴。
机械制造 毕业设计 外文英文文献 翻译 齿轮和齿轮传动
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。
外文翻译--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 Association (AGMA).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 addenda(as 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 pro 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 largergear is decreased, leaving the whole depth the same. This form is know as recess-action gearing.Pressure Angle: Standard angles are 025. Earlier standards include a20and 014-02/1pressure angle that is still used. Pressure angle affects the 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. (includes consideration 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 benecessary to match pinion and gear profiles and leads so that mismatch does not exceed the tolerance on pro 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 the finest 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 pro 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) may require 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 planetarygear 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 engage and disendgage. If these tooth interferences are not compensated for by pro, 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 pro are especially important for high-load , high-speed drives. The graph of sound pressure levelvs tip relief illustrates how tooth pro 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 pro, 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 pro that control 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 atight 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。
齿轮术语中英文对照
齿轮术语中英文对照阿基米德蜗杆Archimedes worm安全系数safety factor; factor of safety安全载荷safe load变形deformation摆线齿轮cycloidal gear摆线齿形cycloidal tooth profile背锥角back angle背锥距back cone distance比例尺scale变速speed change变速齿轮change gear ; change wheel变位齿轮modified gear变位系数modification coefficient标准齿轮standard gear标准直齿轮standard spur gear表面粗糙度surface roughness不完全齿轮机构intermittent gearing补偿compensation参数化设计parameterization design, PD 残余应力residual stress操纵及控制装置operation control device 槽数Geneva numerate侧隙backlash差动轮系differential gear train差动螺旋机构differential screw mechanism差速器differential常用机构conventional mechanism; mechanism in common use承载量系数bearing capacity factor承载能力bearing capacity成对安装paired mounting尺寸系列dimension series齿槽tooth space齿槽宽spacewidth齿侧间隙backlash齿顶高addendum齿顶圆addendum circle齿根高dedendum齿根圆dedendum circle 齿厚tooth thickness齿距circular pitch齿宽face width齿廓tooth profile齿廓曲线tooth curve齿轮gear齿轮变速箱speed-changing gear boxes 齿轮齿条机构pinion and rack齿轮插刀pinion cutter; pinion-shaped shaper cutter齿轮滚刀hob ,hobbing cutter齿轮机构gear齿轮轮坯blank齿轮传动系pinion unit齿轮联轴器gear coupling齿条传动rack gear齿数tooth number齿数比gear ratio齿条rack齿条插刀rack cutter; rack-shaped shaper cutter齿形链、无声链silent chain齿形系数form factor齿式棘轮机构tooth ratchet mechanism插齿机gear shaper重合点coincident points重合度contact ratio传动比transmission ratio, speed ratio传动装置gearing; transmission gear传动系统driven system传动角transmission angle传动轴transmission shaft创新设计creation design垂直载荷、法向载荷normal load从动带轮driven pulley从动件driven link, follower从动件平底宽度width of flat-face从动件停歇follower dwell从动件运动规律follower motion从动轮driven gear粗线bold line粗牙螺纹coarse thread大齿轮gear wheel打滑slipping带传动belt driving单列轴承single row bearing单位矢量unit vector当量齿轮equivalent spur gear; virtual gear当量齿数equivalent teeth number; virtual number of teeth 当量摩擦系数equivalent coefficient of friction当量载荷equivalent load刀具cutter导数derivative倒角chamfer导程lead导程角lead angle等效质量equivalent mass（疲劳）点蚀pitting垫圈gasket垫片密封gasket seal顶隙bottom clearance定轴轮系ordinary gear train; gear train with fixed axes 动力学dynamics动密封kinematical seal动能dynamic energy动力粘度dynamic viscosity动力润滑dynamic lubrication动载荷dynamic load端面transverse plane端面参数transverse parameters端面齿距transverse circular pitch端面齿廓transverse tooth profile端面重合度transverse contact ratio端面模数transverse module端面压力角transverse pressure angle锻造forge 惰轮idle gear额定寿命rating life额定载荷load rating发生线generating line发生面generating plane法面normal plane法面参数normal parameters法面齿距normal circular pitch法面模数normal module法面压力角normal pressure angle法向齿距normal pitch法向齿廓normal tooth profile法向直廓蜗杆straight sided normal worm 法向力normal force 反正切Arctan范成法generating cutting仿形法form cutting非标准齿轮nonstandard gear非接触式密封non-contact seal非周期性速度波动aperiodic speed fluctuation非圆齿轮non-circular gear粉末合金powder metallurgy分度线reference line; standard pitch line 分度圆reference circle; standard (cutting) pitch circle分度圆柱导程角lead angle at reference cylinder分度圆柱螺旋角helix angle at reference cylinder分母denominator分子numerator分度圆锥reference cone; standard pitch cone封闭差动轮系planetary differential复合应力combined stress复式螺旋机构Compound screw mechanism干涉interference刚度系数stiffness coefficient钢丝软轴wire soft shaft根切undercutting公称直径nominal diameter高度系列height series功work工况系数application factor工艺设计technological design工作循环图working cycle diagram工作机构operation mechanism工作载荷external loads工作空间working space工作应力working stress工作阻力effective resistance工作阻力矩effective resistance moment 公法线common normal line公制齿轮metric gears功率power功能分析设计function analyses design共轭齿廓conjugate profiles共轭凸轮conjugate cam惯性力矩moment of inertia ,shaking moment惯性力平衡balance of shaking force冠轮crown gear轨迹生成path generation轨迹发生器path generator滚刀hob过度切割undercutting耗油量oil consumption耗油量系数oil consumption factor横坐标abscissa互换性齿轮interchangeable gears花键spline滑键、导键feather key滑动率sliding ratio环面蜗杆toroid helicoids worm缓冲装置shocks; shock-absorber机械machinery机械平衡balance of machinery机械设计machine design; mechanical design机械特性mechanical behavior机械调速mechanical speed governors机械效率mechanical efficiency机械原理theory of machines and mechanisms机械无级变速mechanical stepless speed changes基础机构fundamental mechanism基本额定寿命basic rating life基于实例设计case-based design,CBD基圆base circle基圆半径radius of base circle基圆齿距base pitch基圆压力角pressure angle of base circle 基圆柱base cylinder 基圆锥base cone极限位置extreme (or limiting) position极位夹角crank angle between extreme (or limiting) positions 计算机辅助设计computer aided design, CAD计算机辅助制造computer aided manufacturing, CAM计算机集成制造系统computer integrated manufacturing system, CIMS计算力矩factored moment; calculation moment计算弯矩calculated bending moment间隙backlash减速比reduction ratio减速齿轮、减速装置reduction gear减速器speed reducer渐开螺旋面involute helicoid渐开线involute渐开线齿廓involute profile渐开线齿轮involute gear渐开线发生线generating line of involute 渐开线方程involute equation渐开线函数involute function渐开线蜗杆involute worm渐开线压力角pressure angle of involute 渐开线花键involute spline键key键槽keyway交变应力repeated stress交变载荷repeated fluctuating load交叉带传动cross-belt drive交错轴斜齿轮crossed helical gears胶合scoring角速度angular velocity角速比angular velocity ratio结构structure结构设计structural design截面section节点pitch point节距circular pitch; pitch of teeth节线pitch line节圆pitch circle节圆齿厚thickness on pitch circle节圆直径pitch diameter节圆锥pitch cone节圆锥角pitch cone angle解析设计analytical design紧边tight-side紧固件fastener径节diametral pitch径向radial direction径向当量动载荷dynamic equivalent radial load径向当量静载荷static equivalent radial load径向基本额定动载荷basic dynamic radial load rating 径向基本额定静载荷basic static radial load tating径向接触轴承radial contact bearing径向平面radial plane径向游隙radial internal clearance径向载荷radial load 径向载荷系数radial load factor 径向间隙clearance静力static force静平衡static balance静载荷static load绝对运动absolute motion绝对速度absolute velocity可靠性reliability可靠性设计reliability design, RD理论廓线pitch curve理论啮合线theoretical line of action 力矩moment 力平衡equilibrium力偶couple力偶矩moment of couple轮坯blank螺旋副helical pair螺旋机构screw mechanism螺旋角helix angle螺旋线helix ,helical line模块化设计modular design, MD模数module磨损abrasion ;wear; scratching耐磨性wear resistance内齿轮internal gear内齿圈ring gear内力internal force内圈inner ring啮合engagement, mesh, gearing 啮合点contact points 啮合角working pressure angle啮合线line of action啮合线长度length of line of action 盘形转子disk-like rotor 抛物线运动parabolic motion疲劳极限fatigue limit疲劳强度fatigue strength偏置式offset偏( 心) 距offset distance偏心率eccentricity ratio偏心质量eccentric mass偏距圆offset circle偏心盘eccentric切齿深度depth of cut曲齿锥齿轮spiral bevel gear曲率curvature曲率半径radius of curvature曲面从动件curved-shoe follower曲线运动curvilinear motion全齿高whole depth权重集weight sets球面副spheric pair球面渐开线spherical involute球面运动spherical motion人字齿轮herringbone gear润滑装置lubrication device润滑lubrication三角形花键serration spline三角形螺纹V thread screw少齿差行星传动planetary drive with small teeth difference 升程rise升距lift实际廓线cam profile输出轴output shaft实际啮合线actual line of action双曲面齿轮hyperboloid gear顺时针clockwise瞬心instantaneous center死点dead point太阳轮sun gear特性characteristics图册、图谱atlas图解法graphical method退火anneal陀螺仪gyroscope外力external force外形尺寸boundary dimension网上设计on-net design, OND微动螺旋机构differential screw mechanism位移displacement蜗杆worm蜗杆传动机构worm gearing蜗杆头数number of threads蜗杆直径系数diametral quotient蜗杆蜗轮机构worm and worm gear蜗杆形凸轮步进机构worm cam interval mechanism蜗杆旋向hands of worm蜗轮worm gear无级变速装置stepless speed changes devices相对速度relative velocity相对运动relative motion相对间隙relative gap象限quadrant橡皮泥plasticine小齿轮pinion小径minor diameter谐波齿轮harmonic gear谐波传动harmonic driving斜齿轮的当量直齿轮equivalent spur gear of the helical gear 心轴spindle行程速度变化系数coefficient of travel speed variation行程速比系数advance-to return-time ratio 行星齿轮装置planetary transmission行星轮planet gear行星轮变速装置planetary speed changing devices行星轮系planetary gear train旋转运动rotary motion压力角pressure angle应力图stress diagram应力—应变图stress-strain diagram优化设计optimal design油杯oil bottle有效圆周力effective circle force圆带传动round belt drive圆弧齿厚circular thickness圆弧圆柱蜗杆hollow flank worm圆角半径fillet radius圆盘摩擦离合器disc friction clutch圆盘制动器disc brake原动机prime mover原始机构original mechanism圆形齿轮circular gear圆柱滚子cylindrical roller圆柱滚子轴承cylindrical roller bearing 圆柱副cylindric pair 圆柱蜗杆cylindrical worm圆锥滚子tapered roller圆锥滚子轴承tapered roller bearing圆锥齿轮机构bevel gears圆锥角cone angle运动副kinematic pair运动粘度kenematic viscosity载荷load展成法generating直齿圆柱齿轮spur gear直齿锥齿轮straight bevel gear直径系数diametral quotient直径系列diameter series直廓环面蜗杆hindley worm质量mass中心距center distance中心距变动center distance change中径mean diameter终止啮合点final contact, end of contact 周节pitch轴shaft轴承盖bearing cup轴承合金bearing alloy轴承座bearing block轴承外径bearing outside diameter轴颈journal轴瓦、轴承衬bearing bush轴端挡圈shaft end ring 轴环shaft collar轴肩shaft shoulder轴角shaft angle轴向axial direction轴向齿廓axial tooth profile转动副revolute (turning) pair转速swiveling speed ; rotating speed转轴revolving shaft转子rotor装配条件assembly condition锥齿轮bevel gear锥顶common apex of cone锥距cone distance锥轮bevel pulley; bevel wheel锥齿轮的当量直齿轮equivalent spur gear of the bevel gear锥面包络圆柱蜗杆milled helicoids worm 准双曲面齿轮hypoid gear自由度degree of freedom, mobility总重合度total contact ratio总反力resultant force总效率combined efficiency; overall efficiency组成原理theory of constitution组合齿形composite tooth form组合安装stack mounting最少齿数minimum teeth number最小向径minimum radius作用力applied force坐标系coordinate frame上面是百度的以下是我自己翻译的肯定有错误···齿轮参数英文及部分翻译NUMER OF TEETH 齿数DIAMETRIAL PITCH 双径节PRESSURE ANGLE (NORM.) 压力角HELIX ANGLE 螺旋角LEAD 导程PITCH DIA. (STAND ＆MESHING) 节圆?BASE DIAMETER 基圆直径? OUTSIDE DIAMETER 齿顶圆直径? ROOT DIAMETER 齿根圆直径? WHOLE DEPTH 全齿高? CIRCULAR PITCH (NORM) 周节? CHORDAL THICKNESS 弦齿高? CHORDAL ADDENDUM 弦齿厚? WIRE SIZEMIC OVER WIRESLEAD CHK IN. @ 90°BLOCK MEASURE 3 TEETH 跨3齿公法线长度?CENTER DISTANCE 中心距BACKLASHNUMBER OF TEETH IN MA TE 配对齿轮齿数AGMA QUALITY (MIN.) 精度等级花键参数及部分翻译FLAT ROOT SIDE FITNUMBER OF TEETH 齿数SPINE PITCH 花键径节PRESSURE ANGLE 压力角BASE DIAMETER 基圆直径PITCH DIAMETER 节圆直径MAJOR DIAMETER 大径FORM DIAMETER ?MINOR DIAMETER 小径CIRCULAR SPACE WIDTH ?MAX. ACTUAL ?MIN. LEFECTIVE ?MEASUREMENT BETWEEN PINS 量棒距PIN DIAMETER 量棒直径LEAD 齿向WIRE SIZE 量棒直径MIC OVER WIRES 跨棒间距BACKLASH 齿侧间隙。
机械制造专业外文翻译--齿轮简介
外文原文：The Introduction of the gearsIn 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. There are also other reasons, as we shall learn.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 other reasons, 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 outvery small loads and are mainly for instrumental applications, and are definitely not recommended for 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 high angular-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 of 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, and that 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 angle on 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 gearmounting, one of the gear is often mounted outboard of the bearing. This means that shaft deflection can be more pronounced and have a greater effect on the contact of teeth. Another difficulty, which occurs in predicting the stress in bevel-gear teeth, is the fact the teeth are tapered.Straight bevel gears are easy to design and simple to manufacture and give very good results in service if they are mounted accurately and positively. As in the case of squr gears, however, they become noisy at higher values of the pitch-line velocity. In these cases it is often good design practice to go to the spiral bevel gear, which is the bevel counterpart of the helical gear. As in the case of helical gears, spiral bevel gears give a much smoother tooth action than straight bevel gears, and hence are useful where high speed are encountered.It is frequently desirable, as in the case of automotive differential applications, to have gearing similar to bevel gears but with the shaft offset. Such gears are called hypoid gears because their pitch surfaces are hyperboloids of revolution. The tooth action between such gears is a combination of rolling and sliding along a straight line and has much in common with that of worm gears.中文译文：齿轮简介在直齿圆柱齿轮的受力分析中，是假定各力作用在单一平面的。
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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 Association (AGMA).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 addenda(as 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 largergear is decreased, leaving the whole depth the same. This form is know as recess-action gearing.Pressure Angle: Standard angles are 025. Earlier standards include a20and 014-02/1pressure angle that is still used. Pressure angle affects the 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. (includes consideration 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 benecessary 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 the finest 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) may require 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 planetarygear 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 engage and 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 that control such interference. Gears also require adequate backlash and root clearance. Noise considerations make backlash an important parameter to evaluate duringdrive 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。