機(jī)械制造專業(yè)英語

1、1. that branch of scientific analysis which motions, times and forces is called mechanics and is made up of two parts, statics and dynamics.研究位移、時(shí)間和力運(yùn)動(dòng)乘力是科學(xué)分析法的一個(gè)分歧，被稱作力學(xué)，力學(xué)由兩大部分組成，靜力學(xué)和動(dòng)力學(xué)。2. for example, if the force operating on a sleeve bearing becomes too high, it will squeeze out the oil film a

2、nd cause metal-to-metal contact, overheating and rapid failure of the bearing. 例如： 如果止推軸承上的作用力過大的話， 會(huì)擠出油膜，引起金屬和金屬之間的相互接觸，軸承將過熱而迅速失效。3. our intuitive concept of force includes such ideas as place of application, direction, and magnitude, and these are called the characteristics of a force. 力的直觀概念包括力的

3、作用點(diǎn)、大小、方向，這些被稱為力的三要素。4. all bodies are either elastic or plastic and will be deformed if acted upon by forces. when the deformation of such bodies is small, they are frequently assumed to be rigid, i.e., incapable of deformation, in order to simplify the analysis.所有的物體既可以是彈性的也可以是塑性的，如果受到力的作用就產(chǎn)生變形。當(dāng)變

4、形很小的時(shí)候它們被假設(shè)成剛體，也就是不產(chǎn)生變形。5. the rigid-body assumption cannot be used in internal stresses and strains due to the applied forces to be analyzed. thus we consider the body to be capable of deforming.剛體假設(shè)不能應(yīng)用于內(nèi)應(yīng)力和內(nèi)應(yīng)變的分析，所以在實(shí)際力的分析時(shí)，要考慮物體的形變。6. if all the forces acting on a particle are balanced, the part

5、icle will either remain at rest or will continue to move in a straight line at a uniform velocity.如果作用在質(zhì)點(diǎn)上所有的力是平衡的，質(zhì)點(diǎn)將會(huì)保持靜止或做做勻速直線運(yùn)動(dòng)。7. a tensile test consists of slowly pulling a sample of material with a tensile load until it breaks. the ends of tensile specimens are usually enlarged to provide ex

6、tra area for grip-ping and to avoid having the sample break where it is being gripped.拉伸試驗(yàn)包括慢慢加載拉伸載荷直到斷裂。拉伸試件兩端加粗為了提供裝夾區(qū)域和避免試件斷裂。8. the usual manner of conducting the test is to deform the specimen at a constant speed. for example, in the universal testing machines, the motion between the fixed and

7、moving crossheads can be controlled at a constant speed. 通常進(jìn)行試驗(yàn)的方法就是使試件以恒定速度發(fā)生變形。例如，在萬能拉伸試驗(yàn)機(jī)上，固定端和移動(dòng)的十字滑塊之間的變形是以恒定速度進(jìn)行的。9. the load that must be applied to enforce this displacement rate varies as the test proceeds. this load f may be divided by the cross-sectional area a to obtain the stress in the

8、 specimen at any time during the test.隨著實(shí)驗(yàn)的進(jìn)行，用來產(chǎn)生位移的載荷是隨位移的變化而變化。在實(shí)驗(yàn)中，載荷f除以橫截面積 a 可以得到任意時(shí)刻點(diǎn)的應(yīng)力。10. however actual measurement of l is preferable where this is feasible. stress and strain based on the initial (undeformed) dimensions, ai and li, are called engineering stress and strain. 然而，在可行的位置上 l

9、的實(shí)際測(cè)量是更可取的， 基于原始尺寸 ai 和li 的應(yīng)力和應(yīng)變稱為工程應(yīng)力和工程應(yīng)變。11. ductile and brittle materials behave differently in compression test as well. the compression test is conducted on short cylindrical specimens placed between parallel plates. 塑性和脆性材料在壓縮試驗(yàn)中表現(xiàn)的特性是不相同的。壓縮試驗(yàn)是把短圓柱形試件放在兩平行平板之間進(jìn)行的。12. the compression test dia

10、gram for these materials retains the qualitative features of the tension test diagram. the ultimate compressive strength of a brittle of a brittle material is determined in the same way as in tension. 材料壓縮試驗(yàn)圖保持了拉伸試驗(yàn)圖性能上的特征。脆性材料的最大壓縮強(qiáng)度與最大拉伸強(qiáng)度得到的方法相同。13. virtually all machines contain shafts. the most

11、 common shape for shafts is circular and the cross section can be either solid or hollow (hollow shafts can result in weight savings). 幾乎所有的機(jī)器都有軸，最常用的外形是圓形的，橫截面是空心的或?qū)嵭牡膱A形截面（空心軸可以減少重量）。14. a shaft must have adequate torsional strength to transmit torque and not be overstressed. it must also be torsio

12、nally still enough so that one mounted component does not deviate excessively from its original angular position relative to a second component mounted on the same shaft.一個(gè)軸必須有足夠的扭轉(zhuǎn)強(qiáng)度來傳遞扭矩而不會(huì)破壞，同樣也必須有足夠的扭轉(zhuǎn)剛度，這樣安裝軸就不能過度偏離相對(duì)于安裝在同一軸上第二個(gè)零件的原始位置。15. shafts are mounted on bearings and transmit power throu

13、gh 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.軸安裝在軸承上通過齒輪，滑輪，凸輪和離合器這些裝置傳遞力。這些裝置可以產(chǎn)生使軸彎曲的力，所以軸必修有足夠的剛性防止支撐軸承的過載。16. in addition, the shaft mu

14、st be able to sustain a combination of bending and torsion and bending.另外，軸必須能承載彎扭組合的載荷，因此，這樣就必須考慮彎扭組合的等效載荷。17. components such as gears and pulleys are mounted on shafts by means of key. the design of the key and the corresponding keyway in the shaft must be properly evaluated.齒輪和滑輪構(gòu)件是用鍵的方式連接在軸上的，鍵

15、和對(duì)應(yīng)的鍵槽的設(shè)計(jì)必須進(jìn)行估算。18. 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.軸設(shè)計(jì)的另一個(gè)重要方面是直接連接兩軸，通過剛性和柔性的聯(lián)軸器裝置來實(shí)現(xiàn)。19. pressure angles for spur gears are usually 14.5 or 20 degrees, although

16、 other values can be used. meshing gears must have the same pressure angles. 直齒輪的壓力角通常為14.5或 20， 另外也使用其它的角度，嚙合齒輪必須具有相同的壓力角。20. the shape of the space between gear teeth on the gear as well as tooth module, so most gear manufacturing methods generate the tooth flank instead of forming.齒輪輪齒之間齒槽的形狀是復(fù)雜的

17、， 并且隨著齒的數(shù)目和模數(shù)變化而變化，因此大多數(shù)齒輪的加工方法是展成齒腹齒廓而不是齒形成形加工。21. worm gears are used where high ratios are desired and where the shafts are nonintersecting and at right angles. 蝸桿蝸輪應(yīng)用于傳動(dòng)比大而且兩軸不相交但相互垂直的情況下。22. it has the great advantage that the cutting tool is a simple rack with ( nearly ) straight sided teeth w

18、hich can easily be ground accurately.這種方法有很大的優(yōu)勢(shì)，切削工具是一個(gè)簡(jiǎn)單的帶有直齒邊的齒條23. modern shapers cutting car gears can run at 2000 cutting per minute. the shape of the cutter is roughly the same as an involute gear but the tips of the teeth are rounded.現(xiàn)代切削汽車的成型器齒輪轉(zhuǎn)速可達(dá)每分鐘 2000 轉(zhuǎn)，齒刀形狀與漸開線大致相同，但齒頂是圓形的。24. bevel g

19、ears are often used when two shafts are at right angles to each other and their centerline extensions intersect; however, some bevel gears are at angles other than 90 degrees. 圓錐齒輪一般應(yīng)用于相互垂直的兩軸或兩個(gè)中心線延長(zhǎng)線的相交軸中，也可用于不垂直的兩軸中。25. the purpose of any cam is to produce a displacement of its follower; a second

20、ary follower is often used to produce additional displacement in another location.使用凸輪的目的是使從動(dòng)件產(chǎn)生位移，次級(jí)從動(dòng)件在另一位置產(chǎn)生附加運(yùn)動(dòng)。26. the relative vertical position of point a with respect to b needs to be raised if the reaction value at b is excessive. 如果 b點(diǎn)的作用力過大，a 點(diǎn)相對(duì) b 點(diǎn)的相對(duì)垂直位置必須被提高。27. in general, the follow

21、er is considered to be the part that comes in contact with the cam profile. however, when a secondary follower is used, the motion of the secondary follower is dictated by that of the primary follower.總的來說，從動(dòng)件是與凸輪輪廓相接觸的零件，然而，當(dāng)用次級(jí)從動(dòng)件時(shí)，次級(jí)從動(dòng)件的運(yùn)動(dòng)就需通過主要從動(dòng)件來實(shí)現(xiàn)。28. the simplest type of follower is the reci

22、procating type that merely moves up and down ( or in and out ) with the rotation of the cam; the centerline can be either collinear with the cam centerline or offset form it.最簡(jiǎn)單的從動(dòng)件就是隨著凸輪的轉(zhuǎn)動(dòng)而僅做上下（或進(jìn)出）運(yùn)動(dòng)的從動(dòng)件，其中心線可與凸輪中心共線，也可與之偏離。29. fasteners are devices which permit one part to be joined to a second

23、part and, hence, they are involved in almost all designs. 緊固件是一種連接一個(gè)部分和另一個(gè)部分的裝置，因此，它涉及到幾乎所有的設(shè)計(jì)。30. springs are mechanical members which are designed to give a relatively large amount of elastic deflection under the action of an externally applied load.彈簧是一種被設(shè)計(jì)于在外力作用下產(chǎn)生相對(duì)彈性變形較大的機(jī)械構(gòu)件。31. the lubricati

24、on system provides a constant flow of filtered oil to all moving parts of the engine. the system consists of an oil pan to store the oil, a pump to circulate it, a filter to remove solid abrasive particles, and an oil gauge or light in drivers compartment for checking purposes. 32. the drive line co

25、nsists of mechanisms and units which transmit torque from the engine to the drive wheels and change torque and rpm in magnitude and direction. 33. it has been seen that if the conditions are not very abnormal, sufficient amount of tyre slip taking place under running conditions would release these s

26、tresses completely. 34. much effort is required to crank the engine during starting, since it is necessary to overcome friction in the moving engine components and the resistance offered by the charge being compressed. 35. the clutch is a friction device used to connect and disconnect a driving forc

27、e from a driven member. it is used in conjunction with an engine flywheel to provide smooth engagement and disengagement of the engine and manual transmission. 36. the differential is a gear system that transfers power from the drive shaft to the driving axles. it also permits one driving wheel to t

28、urn faster than the other to prevent skidding and scuffing of tires on turns. 37. the first stage in the production of sand casting must be the design and manufacture of a suitable pattern. casting pattern has to be made larger than the finished casting size to allow for the shrinkage that takes pla

29、ce during solidification and cooling.在型砂鑄造生產(chǎn)中，第一階段是必須設(shè)計(jì)和制造合適的模型，考慮到鑄件在凝固和冷卻期間產(chǎn)生的收縮鑄件模型的尺寸要比鑄件的尺寸大。38. if a hollow casting is to be made the pattern will include extension pieces so that spaces to accept the sand core are molded into the sand. these additional spaces in the mold are termed core print

30、s. 如果鑄造空心鑄件時(shí)模型上包含伸長(zhǎng)桿便于在砂中放置砂芯的空間稱為型芯座。39. sand molds for the production of small and medium-sized castings are made in a molding box. the mold is made in two or more parts in order that the pattern may be removed.中小型尺寸的鑄件砂型是在一個(gè)砂箱中制造，砂型由兩部分或更多部分組成，以利于模型的順利取出。40. this process of filling and ramming ma

31、y be done by hand but mold production is automated in a large foundry with the mold boxes moving along a conveyor, firstly to be filled with sand from hoppers and then to pass under mechanical hammers for ramming.填充和夯實(shí)的過程可以手工完成，但在大型鑄造中砂型的制造是自動(dòng)完成的，砂箱隨著傳送帶移動(dòng)，首先被料斗中的砂子填滿，然后通過機(jī)械錘時(shí)被打?qū)崱?1. the risers shou

32、ld coincide with the highest points of the mold cavity so that the displaced air can readily escape from the mold. the sizes of risers should be such that the metal in them does not freeze too rapidly.冒口應(yīng)該與型腔的最高點(diǎn)相連接，使得進(jìn)入的空氣可以容易的從模型中溢出，冒口的尺寸應(yīng)該足夠大使模型中金屬不會(huì)太快凝固。42. when the metal that has been poured in

33、to a sand mold has fully solidified, the mold is broken and the casting is removed. the casting still has the runner and risers attached to it and there will be sand adhering to portions of the surface. 當(dāng)熔的金屬被傾倒到砂型內(nèi)并充分凝固以后，砂型將被打破取出鑄件，鑄件上依然帶有橫澆口和冒口并且依然有砂子粘在表面。43. forging means the shaping of metal by

34、 a series of hammer blows, or by slow application of pressure. the simplest example is a blacksmith s forging of a hot piece of metal by hammering the work-piece on an anvil.鑄造是通過一系列的錘打或是在緩慢的加載壓力的場(chǎng)合使金屬成型的一種方法，最簡(jiǎn)單的實(shí)例就是熱的金屬的自由鍛，即通過鐵砧上錘打鍛件。44. heavy smith s forging is fundamentally similar, differing o

35、nly in the scale of the operation. the work-piece may be an ingot of 100 tons and the deforming force provided by a massive forging hammer, but the whole process is controlled by the master smith, who decides each time where, and with what force, the blow should take place. 重型自由鍛和自由鍛基本相似，僅在操作的規(guī)模上有所不

36、同，鍛件可以是一個(gè) 100 噸的鐵塊，鍛壓力由一個(gè)巨大的鍛錘提供，但是整個(gè)鍛造過程由操作者控制。他來決定什么時(shí)候用多大力打到什么地方。45. forging operations may be carried out using either forging hammers or forging presses. with a press, as opposed to a hammer, pressure is slowly applied and plastic deformation tends to occur fairly uniformly throughout the materi

37、al.鍛造操作者既可以用鍛錘也可以用鍛壓力來實(shí)現(xiàn)操作，用鍛壓力和鍛錘相反，在壓力緩慢作用使整個(gè)均勻桿產(chǎn)生塑性變形的趨勢(shì)。46. forging hammers are of two basic types with the large hammer either dropping on to the work-piece accelerated by gravity alone or, as in the steam hammer, accelerated by both gravity and steam pressure.鍛錘有兩種基本類型，既可以用很大的錘子通過作用在工件上也可以用蒸汽壓

38、力作用在工件上或者是兩者結(jié)合。47. smith s or open-die forging is used for making very large forgings or when the number of forgings of a particular design is small. open-die forging is also used to preform metal prior to final shaping by means of closed-die forging.自由鍛或開模鍛用于制造大型的鍛件或者特殊設(shè)計(jì)的小鍛件，開模鍛用于預(yù)成型金屬，在最終金屬成型之前通常

39、使用閉模鍛。48. closed-die forging involves the use of accurately machined die blocks. the capital cost of a pair of die blocks is high, but this is allowable when it is required to make forgings to close dimensional tolerances and in large quantity, as would be the case for, say, connecting rods for the engine of a popular