机电工程专业英语－朱林 杨春杰.ppt

contents, lesson 1 introduction to machinery design lesson 2 mechanisms lesson 3 machine parts (i) lesson 4 machine parts (ii) lesson 5 engineering graphic in the third- angle projection lesson 6 introduction to cad/cam/capp lesson 7 a discussion on modern design optimization lesson 8 using dynamic simulation in the development of construction machinery lesson 9 engineering tolerance lesson 10 numerical control, lesson 11 introduction to heat pipe technology in machining process lesson 12 introduction to material forming lesson 13 material forming processes lesson 14 introduction to mould lesson 15 mould design and manufacturing lesson 16 heat treatment of metal lesson 17 virtual manufacturing lesson 18 fluid and hydraulic system lesson 19 product test and quality control lesson 20 introduction of automobile engine, lesson 21 the automobile components lesson 22 mechatronics lesson 23 industrial robots lesson 24 an army of small robots lesson 25 introduction to mems lesson 26 dialogueat cimt lesson 27 virtual manufacturing, lesson 1 introduction to machinery design 1.1 text 1machinery 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 components the major part of a machine is the mechanical system. 3and 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.,mechanical design process product 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. the complete process is often outlined as in fig.1.1.,fig.1.1 design process model,recognition of need sometimes, 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 problem definition 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.,synthesis the 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.,analysis analysis 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.,evaluation evaluation is the final proof of a successful design and usually involves the testing 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.,presentation communicating 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 design machinery 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., 1.2 words and phrases,machinery n. 总称 机器，机械 trivial adj. 琐细的，平常的，微不足道的 mechanism n. 机构 chain n. 链(条)，镣铐，一连串，一系列 turbine blade n. 涡轮机叶片 crankshaft n. 曲轴 propeller n. 推进者, 推进物, 尤指轮船、飞 机上的螺旋推进器 discard v. 丢弃, 抛弃 recognition n. 识别 trigger v. 引发, 引起, 触发,vague adj. 含糊的, 不清楚的 synthesis n. 综合 ideation n 构思能力，思维能力，构思过程 aggregate adj. 合计的, 集合的 prototype n. 样机，原型 erroneous adj. 错误的, 不正确的 iteration n. 反复 competent adj. 有能力的, 胜任的 versatile adj. 通用的, 万能的, 多才多艺的, 1.3 complex sentence analysis,1 machinery design is either to formulate an engineering plan for the satisfaction of a specified need or to solve an engineering problem. eitheror：或或 formulate：明确地表达，阐明 机械设计用以阐明满足某种特殊需要的工程计划或解决具体的工程问题。 2 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 best. 对于设计者来说，一开始就能准确判定出令人满意的设计方案，并能加以区别以选择最好的，这一点很重要。,3 and the mechanical system is decomposed into mechanisms, which can be further decomposed into mechanical components. be decomposed into：被分解为 which 引导一个定语从句，在从句中做主语，指前 面的 mechanisms。 机械系统可以分解为机构, 机构又可以进一步分解为机械零件。, 1.4 exercise 1.4.1translate the following paragraphs,the practice of design can be one of the most exciting and fulfilling activities that an engineer can undertake. there is a strong sense of satisfaction and pride in seeing the results of ones creative efforts emerge into actual products and processes that benefit people. to do design well requires a number of characteristics.,1.4.2 choose the proper answer to fill in the blank and translate the sentences,1they are using a ( ) shovel to clear up the streets. 2many products are made by ( ). 3there is not a ( ) who hasnt had this problem. 4machinery design involves a range of disciplines in materials, ( ), heat, flow, control, electronics and production. 5the allies finally smashed the nazi war ( )., lesson 2 mechanisms 2.1 text a mechanism is the members combination more than two or two connections with the members to realize the regulation motion made up by way of the activity. they are the component of machinery. activity connections between two members that have the relative motion are called the motion pairs.,fig.2.1 types of cams, 2.2 words and phrases,mechanism n. 机构 motion pairs 运动副 disposition n. 配置；排列 machine frame 机座，机架 coordinate n. 坐标 motivity member 原动件 parameter n. 参变量 driven member 从动件 free degree 自由度 categorize v. 分类 category n. 种类，逻辑范畴 planar adj. 平面的，平坦的 spherical adj. 球的，球形的 spatial adj. 空间的 loci n. locus的复数形式 点的轨迹, 2.3 complex sentence analysis,1 the motion specific property of mechanism chiefly depends on the relative size between the member, and the character of motion pairs, as well as the mutual disposition method etc. 机构的运动特性主要取决于构件间的相对大小、运动副的性质以及相互配置方式等。 specific property：特性 as well as：不但而且；和一样；和；也，表示递进或并列关系。 2 the criterion which distinguishes the groups，however，is to be found in the characteristics of the motions of the links 然而，区别分类的标准在于连杆装置的运动特性。, which引导定语从句，修饰criterion to be found为不定式被动语态。 1inks译为“连杆装置”。 3 this characteristic makes it possible to represent the locus of any chosen point of a planar mechanism in its true size and shape on a single drawing or figure 有了这一特点，就能够在单个图形或图像上，以实际的尺寸和形状来绘出平面机构的任意选择点的轨迹。 makes it possible：使可能 represent：描绘，展现 planar mechanism：平面机构。 in size and shape：在大小和形状方面, 2.4 exercise：translate the lineate phrases and fill in the brackets.,该机构为平面四连杆机构( )， 1为机架( )，2为原动件( )， 3、4为从动件( )，a为回转副( )， 属于低副( )，b为固定连接( )。 构件( )4中的焊接符号( )表示4为一个构件。 该机构的自由度数( )必须等于原动件数，才能实现确定的运动( )。, lesson 3 machine parts (i) 3.1 text gears gears 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 v-belt the rayon and rubber v-belt are widely used for power transmissionsuch belts are made in two series：the standard v-belt and the high capacity v-beltthe belts can be used with short center distances and are made endless so that difficulty with splicing devices is avoided,chain drives the first chain-driven or “safety” bicycle appeared in 1874, and chains were used for driving the rear wheels on early automobiles. 4today, 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 the development 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., 3.2 words and phrases,gear n. 齿轮 projection n. 凸出 cycloidal adi. 摆线的 cycloidal profile 摆线轮廓 involute adi. 渐开线的 involute profile 渐开线轮廓 conjugate adi. 共轭的 pinion n. 小齿轮 dimension n. 量纲 mate v. 啮合 engagement n. 啮合 tangency n. 接触 pitch n. 齿节,intersect v . 相交，交叉 disposition n. 排列，配置 helical gear 螺旋齿轮 spur gear 正齿轮，直齿轮 worm n. 蜗轮，蜗杆 bevel gear 伞形齿轮，锥齿轮 hourglass n 沙漏 v-belt v型带 splice n. 连接 pulley n. (皮带)轮 groove n. 沟，槽 tractive adi. 牵引的,clearance n. 间隙 chain drive 链传动 prototype n. 模型，原型机 saw n. 锯 escalator n. 自动扶梯 roller chain 套筒滚子链条，滚子链 bead chain 滚珠链条 bushing n. 套筒 sprocket n. 链轮 strand n. 排，列 venetian blind 威尼斯百叶窗，软百叶窗, 3.3 complex sentence analysis,1 gears 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 operating in pairs： 分词短语，修饰前面的gears。 that引导的从句，修饰前面的gears。 by means of表示“借助”、“通过”的意思 齿轮是直接接触的实体，成对使用，在称为齿的凸起的连续啮合作用下，齿轮将运动和力从一根转轴传递到另一根转轴上，或者将运动和力从一根轴传递到滑块(齿条)上。,2 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. 假设一渐开线直齿轮是用橡胶制成的，并且能够均匀扭转，那么，两端就会绕着轴线做相对的转动，这样，开始是直的并平行于轴线的小齿轮上的齿，就变成了螺旋形。 were made of：“由组成” so that引导结果状语从句 parallel to：“平行于”,3 sufficient clearance must be provided at the bottom of the groove to prevent the belt from bottoming as it becomes narrower from wear. at the bottom of“在的底部” preventfrom wear“防止磨损” 4 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 the development of efficient agricultural machinery, well-drilling equipment, and mining and construction machinery. 如今，随着现代设计和制造方法的改进，链传动的应用越来越广泛，大大提高了农业机械、钻探设备、矿业和建筑机械的效率。 superior to表示“优于”的意思。 and引导的是一句并列句。, 3.4 exercise： 3.4.1 translate the following paragraphs,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. parallel shafts, however, can also be connected by gears of another type, and a spur gear can be mated with a gear of a different type., 3.4 exercise： 3.4.2 write the name of the following parts and brief description of the roller chain on the structure and assembly relations.,fig.3.1 structure, lesson 4 machine parts (ii) 4.1 text fastener 1fasteners 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.,shaft virtually 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).,bearing a 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.,fig.4.1 journal bearing, 4.2 words and phrases,device di5vais n. 器件；设备；装置 fastener n. 紧固件，紧固零件 classification n. 分类，类别 removable adi. 可移动的，可拆的 semipermanent adj. 半永久性的 cotter pin n. 开口销，开尾销 disassemble v 拆开，分散 rivet n. 铆钉；v. 铆；铆接 weld v. 焊接，熔接 nuisance n. 障碍，损害 rattle v.& n 发出喀啦声，硬物质的撞 击声 nut n 螺帽 bolt n. 螺钉，螺栓 v. 用螺栓连接,screw n. 螺钉，螺旋丝杆 lock washer n. 锁紧垫圈，止动垫圈，防松垫圈 resilience n. 弹力，弹性 aluminum n. 铝(金属元素符号) shaft n. 轴 bearing n. 轴承，支承 gear n. 齿轮 cam n. 凸轮，靠模 clutch v.& n. 抓住，离合器 cold-roll v.& n 冷轧，冷轧机 forge v.& n 锻造，打制 flexible adj. 柔软的，适用性强,friction n. 摩擦 brake v. 破坏，折断，损坏 wear v.& n 磨损，耗损 arrangement n. 布置，排列 contaminant n. 杂质，污染物质 sealing arrangement n. 密封装置 hostility n. 敌意，恶劣 appreciation n. 评价，欣赏 interference n. 干涉，过盈,fretting n. 微振磨损 corrosion n. 腐蚀 abut v. 邻接，倚靠 stress concentration 应力集中 shoulder n. 轴肩 chamfer v.& n.倒角，倒圆，开槽 journal bearing n. 滑动轴承 cylinderical adj. 圆筒状的，柱状的 lubricant n. 润滑剂，润滑材料 compatible adj. 相适用，和谐的，一致的, 4.3 complex sentence analysis,1 fasteners are devices which permit one part to be joined to a second part and, hence, they are involved in almost all designs. 紧固件可以将一个零件与另一个零件相连接。因此，几乎在所有的设计中都要用到紧固件。 which引导定语从句修饰devices。 to be joined to a second part第一个不定式to表示目的。be joined to是介词词组，to表示“到”的意思。 are involved in表示“涉及”、“包括”的意思。 2 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.,这种螺栓长度的变化可由多种因素引起螺栓内部蠕变、弹性丧失、螺栓与被连接件间的热膨胀差异或磨损。 factors-creep是复合词，表示“引起蠕动的因素”。 loss of resilience表示“弹性丧失”。 3 in general, the bending deflection of a shaft should not exceed 0.01 in. per ft of length between bearing supports. 一般来说，在两个轴承支承之间，轴在每英尺长度上的弯曲变形不应该超过0.01英寸。 0.01 in. per ft表示“每英尺长度上为0.01英寸”。 ft是foot(英尺)的简写；in是inch(英寸)的简写。 between bearing supports中between表示两者之间，可译为在两轴承支承之间。,4 where speeds are high special cooling arrangements become necessary which may increase frictional drag. 在高转速场合下需要有专门的冷却装置，这可能会增大摩擦阻力。 where引导非限制性定语从句，表示“在哪里”。 which may increase frictional drag修饰主语 cooling arrangements，因为谓语比较短而放在谓语最后。, 4.4 exercise：translate the following paragraphs,a bearing is a connector that permit the connected members to either rotate or translate (more to and from) relative to one another but prevents them from separating in the direction in which loads are applied. in many cases one of the members is fixed, and the bearing acts as a support for the moving member., lesson 5 engineering graphic in the third-angle projection 5.1 text 1graphics comes to our vocabulary from the greek word grapho, whose extended meaning is “drafting” or “drawing”, the drawing is the primary medium for developing and communicating technical ideas. engineering drawings provide an exact and complete description of objects. in addition to a description of the shape of an object, an engineering drawing gives all further information needed to manufacture the object drawn, such as dimensions, tolerances, and so on. so it is often said the engineering drawing is the common language of engineering. every engineer must master this language.,formation of three-projection views,three projection planes system: sin