2022年机械工程专业英语.docx

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1、精品学习资源Lesson11 、 the branch ofscientificanalysis, whichdeals with motions, time, and forces, is called mechanics and is madeup of two parts, statics and dynamics. Statics deals with the analysis of stationary systems, i.e., those in which time is notafactor, anddynamicsdeals withsystems, which chang

2、e with time.对运动时间和作用力作出科学分析的分支成为力学；他由静力学和动力学两部分组成；静力学对静止系统进行分析，即在其中不考虑时间这个引述，动力学对大事而变化的系统进行分析；2 、 Anytwosuch forces actingon a body constitutea couple. The arm of the couple is the perpendicular distancebetween their lines of action, and the plane of the couple is the plane containing the two lines

3、of action.作用在一个刚体上的两个这样的的里构成一个力偶；力偶臂是这两个条作用线之间的垂直距离，力偶面是包含着两条作用线的平面；3 、 Mechanics deal withtwo kinds of quantities:scalars andvectors.Scalar quantitiesare those withwhicha magnitudealoneisassociated.Examplesofscalar quantities in mechanics are time, volume,density, speed, energy, and mass. Vector qu

4、antities,on the other hand, possess direction as well as magnitude. Examples of vectors are displacement, velocity, acceleration, force, moment, and momentum.力学涉及两种类型的量，标量和矢量；标量是那些只有大小的量；在力学中标量的例子有时间、体积、密度、速率、能量和质量；另一方面，矢量既有大小又有大小又有方向；矢量的例子有位移、速度、加速度、力、力矩、动量； Lesson2（此课后面没翻译，翻译的不太精确谅解）1 、The turning

5、 of a part in a lathe is another example ofseveral forces in action. （ as shown in figure1 ）车床车削是一些力在起作用的另一个例子；figure1 如图 ；2 、 If this workpiece is held between the centers of the lathe, the centers exert a compressive force against the work.假如这个工件在放在车床中心之间,中心车床对工作产生压力；3、 Rotary motion is required t

6、o drill holes, turn parts in a lathe, mill surfaces, or drive a generator or fan belt.扶轮运动需要去钻孔，在车床上转换两件,表面 ,或驱动发电机或风扇皮带4 、Harmonic and IntermittentMotion （谐和运动和间歇运动） : Any simple vibration, such as the regular back, andforthmovementofthe end ofapendulum,issimple harmonic motion.Lesson41 、 Virtually

7、 all machines contain shafts. The most common shape for shafts is circular and the cross section can be either solid or hollow.实际上，几乎全部的机器中都装有轴；轴的最常见的外形是圆形，其截面可以是实心的，也可以是空心的（空心轴可以减轻重量）；有时也采纳矩形轴，例如， 螺丝起子的头部 .套筒扳手和掌握旋钮的杆；2 、 A shaft must have adequate torisonal strength to transmit torque and not be o

8、ver stressed it must also be torsional stiff enough so that one mounted component doesnot deviate excessively from its original angular position relative to a second component mounted on the same shaft.为了在传递扭矩时不发生过载，轴应当有适当的抗扭强度；轴仍应当具有足够的抗扭强度，以使在同一轴上的两个传动零件之间的相对转角不会过大；3 、Components such as gears and

9、pulleys are mounted on shafts by means of key. The design of the key and the correspondingkeywayintheshaftmustbeproperly evaluated.Forexample,stress concentrationsoccurin shafts due to keyways, and the material removed to from the keyway further weakens the shaft.齿轮和皮带轮等零件通过键连接在轴上；在键及轴上与之相对应的键槽的设计中，

10、必需进行认真的运算；例如，轴上的键槽会引起应力集中，由于键槽的存在会使轴的横截面积减小，会进一步减弱轴的强度；4、Another important aspect of shaft design is the method of directly connecting one shaft to another. Devices such as rigid and flexible couplings accomplish this.轴的设计工作中的另一个重要方面是一根轴与另一根轴之间的直接连接方法；这是由刚性或者弹性联轴器来实现的；Lesson51 、 Thetermshaftusuallyr

11、eferstoarelativelylong member of round cross section that rotates and transmits power.Oneormorememberssuchas gears ,sprockers,pullys,and cams are usually attached to the shaft by means of pins, keys,splines,snap rings,and other devices . These latter members are among the associated parts consedered

12、 in this text,as ate couplings and universal joints , which serve to connect the shaft to the source of power or load.2 、 It is apparent that shafts can be subjected to various combinations of axial,bending,and torsional loads,and that these loads may be static or fluctuating.3、Torsional defection c

13、an affect the accuracy of a cam or geardrivenmechanism.Furthermore,thegreaterthe flexibility-eitherlateralortorsional-thelowerthe corresponding critical speed.4、A gear can be gripped axially between a shoulder on theshaft and a spacer ,with torque being transmitted through a欢迎下载精品学习资源keyways.Lesson7

14、1、Fasteners are devices which permit one part to be joinedto a second part and ,hence,they are involved in almost all designs . The acceptability of any product depends not only on the selected components , but also on the means by which they are fastened together. The principal purposes of fastener

15、s are to provide the following design features ；紧固件是将一个零件与另一个零件进行连接的零件；因此，几乎在全部的设计中都要用到紧固件；人们对于任何产品的中意程度不仅取决于其组成部件，仍取决于其连接方式；2 、 Theimportanceoffasteners can be realizedwhen referringroanycomplexproduct,Inthecase ofthe automobile,there are literally thousands of parts whichare fastened together to p

16、roduce the total product.The failure or looseningofa singlefastener couldresult ina simple nuisance such as a door rattle or in a serious situation such as a wheel coming off.Such possibilitiesmustbe taken intoaccount inthe selection of the type of fatener for the specific application.通过任何一个复杂的产品，都可

17、以熟悉到紧固件在其中的重要性；以汽车为例，它是由数千个零件连接在一起而成为一辆车；一个紧固件的失效或松脱可能会带来像车门嘎嘎响这类小麻烦，也可能造成像车轮脱落这种严峻的后果；因此，在为一个特定的用途挑选紧固件 时，应当考虑到上述各种可能性；Lesson81、 Threadedfasternersperformthefunctionof locating ,clamgping ,adjusting ,and transmiting force fromonemachine membertoanother .Theyare thoroughly standardized and generally

18、designedforuseinmass production of machines.2、 Matching external and internal threads so that they aremay be assembled is the key to all thread fasteners.3、 A particular SAE grade specilication can be met by a number of differentsteels, thus faster manufacturers have some latitude in selecting the m

19、aterials best suited to their specific production faclities.4、 For moderate loads and speedes the correct selection ofa standard of the bearingon the basis of load rating will usually secure satisfactory performance. 对于中等载荷和转速，依据额定负荷挑选一个标准轴承，通常都可以保证其具有令人中意的工作性能；5、The deflection of less magnitude tha

20、n that of the shafts or other components associated with the bearing . 当载荷较大时，轴承零件的变形，尽管它通常小于轴和其它与轴承一起工作的零部件的变形，将会变得重要起来；Lesson91 、 Where speeds are highspecial coolingarrangementsbecome necessary which may increase frictional drag .在转速高的场合需要有特地的冷却装置，而这可能会增大摩擦阻力；2 、 It is not surprisingthat ,owingto

21、the highstresses involved,apredominantformoffailureshouls be metal fatigue,and a good deal ofworkis currentlyin progress intended to improve the reliability of this type of bearing .滚动轴承由于在工作中会产生高的应力，其主要失效形式是金属疲惫，这一点并不古怪，目前正在进行大量的工作以求改进这种轴承的牢靠性；3、 The fit of the bearing races onto the shaft or onto

22、the housing 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.轴承套圈与轴或轴承座的的协作特别重要，由于它们之间的协作不仅应当保证所需要的过盈量，而且也应当保证轴承的内部间隙；4、The inner race is frequently located axially by abutting against a s

23、houlder .Aradius at this point is essential for the avoidanceofstressconcentrationandballraces raeprovidede with a radius or chamfer to allow space for this .内圈通常是通过紧靠在轴肩上进行轴向定位的；轴肩出的圆弧半径主要是为了防止应力集中；在轴承内圈上加工出一个圆弧或者倒角，用来供应容纳轴肩处圆弧半径的空间；5、Where life is not the determing factor in design ,it is usual to

24、 determine maximum loading by the amount to which a bearing will deflect under load .在使用寿命不是设计中的打算因素的场合，通常根据轴承担载荷时产生的变形量来确定其最大载荷；Lesson131、One of the primary considerations in designing any machine or structure is that the strength must be sufficiently greater that the stress to assure both safety a

25、nd reliability. To assure that mechanical parts do not fail in service, it is necessary to learn why they sometimes do fail.Then we shall be able to relate the stresses withthe strengths to achieve safety.在设计任何机器或者结构时，所考虑的主要事项之一是其强度应当比它所承担的应力要大得多，以确保安全与牢靠性；要保证机械零件在使用过程中不发生失 效，就必需知道它们在某些时候会失效的缘由，然后，

26、才能将应力与强度联系起来，以确保其安全；2 、 Ideally,indesigningany machineelement, the engineer should have at his disposal the results of a great many strength tests of the particular material chosen. These tests should have been made on specimens having the same heat treatment, surface roughness, and size as the elem

27、ent he proposes to design, and the tests should be made under exactlythesame loadingconditionsas thepartwill欢迎下载精品学习资源experience in service.设计任何机械零件的抱负情形为，工程师可以利用大量的他所选用的这种材料的强度试验数据；这些试验应当在与所设计的零件有相同的热处理，表面粗糙度和尺寸大小的试件进行，而且试验应当在与零件使用过程中承担的载荷完全相同的情形下进行；3 、 Most hardness-testing systems employ a standa

28、rd load which is applied to a ball or pyramid in contact withthe material to be tested. The hardness is then expressed as a function of the size of the resulting indentation. This means that hardness is an easy property to measure, because the test is nondestructive and test specimens are not requir

29、ed. Usually the test can be conducted directly on an actual machine element.大多数硬度试验系统是将一个标准的载荷加在与被试验材料相接触的小球或者棱锥上；因此，硬度可以表示为所产生的压痕尺寸函数；这说明由于硬度是非破坏性试验，而且不需要特地的试件，因而硬度是一个简单测量的性能；通常可以直接在实际的机械零件上进行硬度试验；Lesson171、 The first step in themanufacture of any product is design, which usually takes place in sev

30、eral distinct stages:a conceptual ； b functional ； c production design. During the conceptual design stage, the designer is concerned primarily with the functions the product is to fulfill.制造任何产品的第一步工作都是设计；设计通常可以分为几个明确的阶段；（a）概念设计； b 功能设计 c生产设计；在概念设计阶段，设计者着重考虑产品应当具有的功能；2、 Often a prototype or working

31、 model is made that can be tested to permit evaluation of the product as to function, reliability, appearance, serviceability, and so on.通常要制造出样机或着实物模型，并对其进行实验，评判产品的功能、牢靠性、外观和修理保养性等3 、 As manufacturing progresses, it is inevitable that situations will arise that may require modifications of the mate

32、rials being used. Experience may reveal that substitution of cheaper materials can be made.在制造过程中，不行防止地会显现对使用中的材料做一些更换的情形；体会说明，可以采纳某些廉价材料作为代替；24/27 课Working drawings are the drawings from which a design is implemented. All principles of orthographic projection and techniques of graphics can be used

33、to communicate the details of a project in working drawings. A detail drawing isa working drawing of a single part or detail within the set of working drawings.工作图是将设计变为实际产品所依据的图样；全部的正投影原理和绘图技术都可以用来在工作图中表达一个工程中的细节；零件图是在一整套工作图中关于一个零件（或细节）的工作图；Title Blocks In practice, title blocks usually contain the

34、 title or part name, drafter, date, scale, company, and sheet number. Other information, such as tolerances, checkers, and materials, also may be given. Any modifications or changes added after the first version to improve the designis shown in the revision blocks.标题栏在实践中，标题栏中通常包括标题或零件名称、制图员、日期、比例、公

35、司和图号；另外，仍可以包含公差、审核人员和材料等信息；在第一次制图之后，任何为了改进设计方案而作的修改和更正都应当在修改栏中标明；The allocation of proper production tolerances is therefore a most important task if the finished product is to achieve its intended purpose and yet be economical to produce. The size of the tolerances, as specified by the designer, de

36、pends on the many conditions pertaining to the design as well ason past experience with similar products if such experience is available.要使产品能够以较低的价格被生产出来并且能够满意设计的要求，规定适当的加工公差是最为重要的工作；公差的大小是由设计人员所确定的，它取决于很多与设计有关的条件以及过去在设计类似产品时所获得的体会（假如有这方面体会的话）；A part is said to be at the least material conditionLMC

37、 when the dimensions are all at the limitsthat give a part with the smallest amount of material.当全部的尺寸都处在答应零件含有的材料量为最小的极限 状 态 时 ， 就 称 这 个 零 件 处 于 最 小 实 体 状 态（ LMC ）；If the variations due to chance causes are too great, it is usually necessary to move the operation to more accurate equipment rather t

38、han spend more effort intrying to improve the process.假如随机缘由对尺寸变化的影响过大，一般来说采纳更精密的加工设备，要比花费更多精力来转变生产过程更为有效Lesson291、Thetechniqueofdimensioningpartswithina require range ofvariation to ensure interchangeabilityis called tolerancing.Each dimensionis alloweda certain degree of variation within a specifi

39、ed zone ,or tolerance .for example, a parts dimension mightbe expressed as 20+- 0.50,whichallows a tolerance variationin size of 1.00 mm.欢迎下载精品学习资源给零件标注尺寸使其在一个规定的区间内变动，以保证他们具有互换性的技术称为公差技术；答应每个尺寸在规定范畴内具有肯定的变动量，称为公差；例如，一个零件的尺寸可以被表示成20+-0.50 ，其公差（尺寸变动量）为 1.00mm；单词 basic hole system 基孔制 basic shaft syst

40、em 基轴制Leesson331Engineering and technology students must became computer literate, to understand the applications of computer and their advantages. Not to do so will place students at a serious disadvantage in pursuing their careers.工程技术专业的同学们应当通晓运算机，明白运算机的用途和它们的优点；不这样做，就会使同学们在将来的职业生涯中处于特别不利的位置；2 、E

41、ngineers generally agree that the computer does not change the nature of the design process but is a significant tool that improves efficiency and productivity工程师们通常认为运算机不会转变设计过程的性质；3 、 Computerofapplicationsinengineeringand other technical fields. Most graphical solutions that are possible with a p

42、encil can be done on a computer and usually more productively.Applicationsvaryfrom3Dmodelingand finiteelementanalysis to 2D drawings and mathematical caiculation.运算机图形学在工程技术领域的应用几乎没有任何限制，大部分可以铅笔完成的图解方法都可以用运算机完成，而且通常效率更高；其应用从建立三维模型和有限元分析，直到绘制平面图和进行数字运算；4、These systems offer many advantagees over trad

43、itional design and manufacturingsystems, ineludingless design effort,more efficentmaterialuse,reduced lead tine, greater accuracy, and improved inventory controi.包括削减时间工作量，提高材料利用率，缩短产品研制周期，提高精度和改善库存治理；graphicshasan aimost limitless numberLesson361、 engin lathes ,of course ,are general-purpose machin

44、es used in production and maintenance shops all over the world.一般车床是全世界的生产车间和修理车间里广泛使用的通用机床；2、Thetracerorduplicatinglatheis designedto produce irregularly shaped parts automatically.靠模车床或仿形车床被设计用来对外形不规章的零件进行自动加工；3、machineswithawidevarietyofpower accessories.Theprincipalfeatureofallturretlathes, howe

45、ver, is that the tools can perform a consecutive serials of operations in proper sequence. Once the tools have beenset and adjusted ,little skill is required to turn out duplicate parts.高生产率的砖塔车床是装有很多动力附件的特别复杂的机器；然而，全部砖塔车床的主要特点是刀具能按适当次序完成一系列的加工工序；一旦这些刀具被安装调整好后只只需要很低的技术就可以车削加工很多相同的零件；4、The first scre

46、w machine were designed to feed bar stock and wire used in making small screw parts.单轴自动螺丝车床，顾名思义，一次仅能加工一根棒料；With the single spndle machine, the turret indexes around the spindle.在单轴车床上，砖塔环绕主轴转位；Witha multiplespindle maching , however ,the spindle itself indexes.然而，在多轴自动车床上，主轴自己转位；6、A vertical turre

47、t lathe is basically a turret lathe that has been stood on its headstock end.立式砖塔车床基本上就是将其从床头箱一端向下而直立起来的一台砖塔车床；7、 Many of todays more sophisticated lathes are called machining centers since they are capable of performing, in addition to the normal turningoperations, certain milling and drilling operations.当前很多技术更为先进的车床叫做加工中心；由于他们除了完成常规的车削工作之外，仍可以完成某些铣削钻削工作单词： turret 砖塔，六角刀架，六角头general purpose 多方面的，多种用途的Lesson651.According to the Tool & Manufacturing English Handbook , process planning is the systematic determination of the methods by which a product i