外文翻譯---動力傳動系

1、<p><b>　　附件：外文翻譯</b></p><p><b>　　外文原文：</b></p><p>　　PASSAGE A Power Train</p><p>　　The power train serves two functions： it transmits pow

2、er from the engine to the drive wheels, and it varies the amount of torque. The power train includes：1.engine：that produces power；2.transmission：either manual or automatic；3.clutch：used only on

3、manual transmission, or torque converter.：used only on automatic transmission; 4.drive shaft：that transmits the power from transmission to</p><p>　　differential；5.that carries the power to

4、 the two wheel axles.See Fig.5-1.</p><p>　　Manual transmission</p><p>　　The function of a manual transmission,shown in Fig.5-2, is to transfer engine power to the drive shaft

5、 and rear wheels. Gears inside the transmission change the car’s drive-wheel speed and torque in relation to engine speed and torque.This keeps the engine’s output matched as close as possible

6、 to varying road speeds and loads.</p><p>　　A manual transaxle，shown in the Fig.5-3.,is a single unit composed of a </p><p>　　manual transmission, differential, and drive ax

7、les. Most front-wheel-drive（FWD） cars</p><p>　　are equipped with a transaxle. Such transaxle are also found on some front-engined or rear-wheel-drive （RWD）,four-wheel-drive（4WD）cars and on r

8、ear-engined</p><p>　　and rear-wheel-drive cars.</p><p>　　A manual transmission requires use of a clutch to apply and remove engine torque to the transmission input shaft.The

9、 clutch allows this to happpen gradually so that the car can be started from a complete stop.</p><p>　　Manual transmission usually have four or five speeds, and often have “overdrive

10、”, which means that the output shaft can turn faster than the input</p><p>　　Shaft for fuel economy on the highway. When you use it, it will reduce the </p><p>　　engine

11、speed by one-third,while maintaining the same road speed.</p><p><b>　　Clutch </b></p><p>　　Driving a car with a manual transmission, you depress the clutch, select a

12、 gear, and release the clutch while applying power to get the car to move. The clutch allows engine power to be applied gradually when a vehicle is starting out, and interrupts power to av

13、oid gear crunching when shifting. Engaging the clutch allows power to transfer from the engine to transmission</p><p>　　and drive wheel. Disengaging the clutch stops the power transf

14、er and allows </p><p>　　the engine to continue turning without force to the drive wheels.</p><p>　　The clutch basic components are：the flywheel, clutch disk, pressure plate,

15、 release bearing and linkage. See Fig.5-4.</p><p>　　The flywheel is bolted to the crankshaft of the engine. Its main function is to transfer engine torque from the engine to the

16、 transmission.</p><p>　　The clutch disk is basically a steel plate, covered with a frictional material that goes between the flywheel and the pressure plate.</p><p>　　A pre

17、ssure plate is bolted to the flywheel. It includes a sheet metal cover, heavy release springs, a metal pressure ring that provides a friction surface for the clutch disk.</p><p>　　T

18、he release bearing is the heart of clutch operation. When the clutch pedal</p><p>　　is depressed, the throw-out bearing moves toward the flywheel, pushing in the pressure plate’s relea

19、se fingers and moving the pressure plate fingers or levers against pressure plate spring force.</p><p>　　The linkage transmits and multiplies the driver’s leg force to the fork of&l

20、t;/p><p>　　the clutch pressure plate. A mechanical clutch linkage usually consists of the clutch pedal, a series of linkage rods and arms, or a cable. A hydraulic clutch linkage typica

21、lly includes a clutch master cylinder and reservoir, a hydraulic line and a slave cylinder.</p><p>　　Automatic transmission</p><p>　　Both an automatic transmission and a manu

22、al transmission accomplish exactly the same thing, but they do it in totally different ways. The key difference between a manual and an automatic transmissions is that the manual transmission

23、 locks and unlocks and different sets of gears to the output shaft to achieve the various gear ratios, while in an automatic transmission, the same set of gears produces all of different ge

24、ar ratios. </p><p>　　Automatic transmissions are used in many rear-wheel-drive and four-wheel-drive vehicles. Automatic transaxles are used in most front-wheel-drive vehicles. The major c

25、omponents of a transaxle are the same as those in a transmission, except the transaxle assembly includes the final drive and differential gears, in addition to the transmission.</p><p

26、>　　An automatic transmission receives engine power through a torque converter,</p><p>　　which is driven by the engine’s crankshaft. Hydraulic pressure in the converter allows power

27、to flow from the torque converter to the transmission’s input shaft. The input shaft drives a planetary gear set that provides the different forward gears, a neutral position, and one reverse

28、 gear. Power flow through the gears is controlled by multiple-disk clutches, one-way clutches, and friction bands.</p><p>　　Passage B Power Train</p><p>　　Torque Converter&l

29、t;/p><p>　　The key to the modern automatic transmission is the torque converter. It takes the place of a clutch in a manual transmission to send the power from the engine to the t

30、ransmission input shaft. The torque converter offers the advantage of multiplying the turning power provided by the engine.</p><p>　　It has three parts that help multiply the power：an

31、 impeller（or pump）connected to the engine’s crankshaft, a turbine to turn the turbine shaft which is connected to the gears, and a stator（or guide wheel）between the two. See Fig. 5-6.</p>

32、<p>　　The torque converter is filled with transmission fluid that is moved by impeller blades. When the impeller spins above a certain speed, the turbine spins, driven by the impeller.<

33、/p><p>　　Planetary Gearing</p><p>　　Planetary gears provide for the different gear ratios needed to move a vehicle in the desired direction at the correct speed. A planetary

34、gear set consists of a sun gear, planet gears, and a internal ring. See Fig. 5-7.</p><p>　　In the center of the planetary gear set is the sun gear.Planet gears surround the sun ge

35、ar, just like the earth and other planets in our solar system. These gears are mounted and supported by the planet carrier and each</p><p>　　gear spins on its own separate shaft.

36、The planet gears are in constant mesh with the sun and ring gears. The ring gear is the outer gear of the gear set. Its has internal teeth and surrounds the rest of the gear set. Its ge

37、ar teeth are in constant mesh with the planet gears. The number of planet gears</p><p>　　used in a planetary gear set varies according to the loads the transmission is designed to

38、 face. For heavy loads, the number of planet gears is increased </p><p>　　to spread the work load over more gear teeth.</p><p>　　The planetary gear set can provide a ge

39、ar reduction or overdrive, direct drive or reverse, or a neutral position. Because the gears in constant mesh, gear changes are made without engaging or disengaging gears, as is required in a

40、manual transmission. Rather, clutches and bands are used to either hold or release different members of the gear set to get the proper direction of </p><p>　　rotation and/or gear rat

41、io.</p><p>　　Different </p><p>　　On FWD cars, the differential unit is normally part of the transaxle assembly. On RWD cars, it is part of the rear axle assembly. Located i

42、nside the differential case are the differential pinion shafts and gears and the differential side gears. See Fig.5-8</p><p>　　The differential assembly revolves with the ring gear. Axl

43、e side gears are splined to the rear axle or front axle drive shafts.</p><p>　　When an automobile is moving straight ahead, both wheels are free to rotate. Engine power is applied

44、 to the pinion gear, which rotates the ring gear.</p><p>　　Beveled pinion gears are carried around by the ring gear and rotate as one unit. Each axle receives the same power, so ea

45、ch wheel turns at the same speed. See Fig. 5-9.</p><p>　　When the car turns a sharp corner, only one wheel rotates freely. Torque still comes in on the pinion gear and rotates the

46、 ring gear, carrying the beveled pinions around with it. However, one axle is held stationary and the beveled pinions are forced to rotate on their own axis and “walk around” </p><p&g

47、t;　　their gear. The other side is forced to rotate because it is subjected to the </p><p>　　turning force of the ring gear, which is transmitted through the pinions. See Fig. 5-10.&l

48、t;/p><p>　　Drive shaft</p><p>　　A drive shaft and universal joints（U-joints） connect the transmission to the rear drive axle on most rear-wheel-drive vehicles. Many four-wheel-dri

49、ve vehicles also use drive shafts and universal joints, with one drive shaft between the transfer case and rear drive axle and a second drive shaft between the transfer case and the front

50、drive axle. The drive shaft is sometimes called a </p><p>　　propeller shaft.</p><p>　　The drive shaft and U-joints provide a means of transferring engine torque</p><

51、;p>　　to drive axles. The universal joints allow the drive shaft to move up and down, to allow for suspension travel. Some drive shaft also have a slip joints </p><p>　　that allows

52、 the drive shaft to make minor length changes as the vehicle suspension height changes.</p><p><b>　　譯文：</b></p><p><b>　　動力傳動系</b></p><p><b&

53、gt;　　A</b></p><p>　　動力傳動系有兩個作用：它把動力從發(fā)動機(jī)傳送到驅(qū)動輪上，并且改變扭矩的大小。動力傳動系包括：1.發(fā)動機(jī)：制造動力2.</p><p>　　變速器:不是手動就是自動3.離合器：僅用在手動變速器或者液力變矩器4.驅(qū)動軸：把動力從變速器傳到差速器5.差速器：將動力傳到兩個驅(qū)動軸上。</p><p><b>　　

54、手動變速器</b></p><p>　　手動變速器的作用是，把發(fā)動機(jī)動力傳送到傳動軸和驅(qū)動輪。變速器內(nèi)的齒輪，改變車輛驅(qū)動輪和發(fā)動機(jī)之間轉(zhuǎn)速和扭矩的比例。這樣保持發(fā)動機(jī)的輸出盡可能的靠近改變路面速度和最低速度。</p><p>　　一個手動的驅(qū)動橋，是一個由手動變速器，差速器，傳動軸組成的。大多數(shù)前輪驅(qū)動汽車裝有一個驅(qū)動橋。這樣的驅(qū)動橋也能在一些前置引擎或者后輪驅(qū)動，四輪驅(qū)動的

55、汽車，在后置引擎和后輪驅(qū)動的汽車上看到。</p><p>　　一個手動變速器包括使用一個離合器來消除發(fā)動機(jī)扭矩到變速器輸入軸。離合器允許這樣漸漸發(fā)生以至于汽車能夠啟動。</p><p>　　手動變速器通常有四到五個檔位，而且一般有“超速檔”，</p><p>　　對于在路上的燃油經(jīng)濟(jì)性這樣就意味著輸出軸比輸入軸轉(zhuǎn)的更快。當(dāng)你使用變速器的時候，要維持同樣的速度，將減少

56、發(fā)動機(jī)轉(zhuǎn)速的三分之一。</p><p><b>　　離合器</b></p><p>　　駕駛手動擋汽車，你踩下離合器，嚙合了齒輪，然后松掉離合器而汽車會適應(yīng)動力前進(jìn)。離合器可使車輛啟動后發(fā)動機(jī)的動力被逐漸的加載，并可通過切斷動力防止換擋時齒輪被咬碎。離合器嚙合時把發(fā)動機(jī)動力傳送到變速器和驅(qū)動輪。離合器分離停止動力傳輸，在沒有動力傳到驅(qū)動輪上的情況下，發(fā)動機(jī)可以持續(xù)運(yùn)轉(zhuǎn)

57、。</p><p>　　離合器基本的部件是：飛輪，離合器盤，壓力盤，分離軸承和聯(lián)接裝置。</p><p>　　飛輪被螺栓固定在發(fā)動機(jī)的曲軸上。它的主要作用是傳送發(fā)動機(jī)扭矩從發(fā)動機(jī)到變速器。</p><p>　　離合器盤基本就是一塊鋼板，在飛輪和壓力盤中間覆蓋了一種耐摩擦材料。</p><p>　　離合器盤螺栓連接在飛輪上。它包括一張薄片金屬封

58、蓋，彈簧，一個給離合器盤提供摩擦表面的金屬壓力環(huán)。</p><p>　　分離軸承是離合器操縱機(jī)構(gòu)的中心。當(dāng)離合器踏板踩下時，分離軸承指向飛輪，壓盤推進(jìn)釋放了擋板然后移動壓盤彈簧片到壓盤彈簧彈力頂。</p><p>　　聯(lián)接裝置成倍地傳送駕駛員腿部力量到離合器壓盤的膜片。一個機(jī)械離合器連接裝置通常由離合器踏板，一系列連接桿臂或者一組電纜。一個液壓離合器聯(lián)接裝置大體上是由一個離合器制動缸和儲存

59、器，一組液壓管路和一個從動缸。</p><p><b>　　自動變速器</b></p><p>　　自動變速器和手動變速器嚴(yán)格的講都能完成一樣的工作，但他們完成工作的方法完全不一樣。手動變速器和自動變速器的之間的根本區(qū)別在于手動變速器鎖與不鎖在不同的輸出軸來實(shí)現(xiàn)各種傳動比；而在自動變速器上，同一套齒輪裝置能夠提供所有的不同傳動比。行星齒輪副給這樣的自動變速器制造了可能

60、。</p><p>　　自動變速器運(yùn)用在許多后輪驅(qū)動和四輪驅(qū)動汽車上。自動驅(qū)動橋運(yùn)用在大多數(shù)前輪驅(qū)動汽車上。一個驅(qū)動橋的主要零部件和一個變速器的差不多，除了驅(qū)動橋擁有主減速器和差速器而變速器沒有。</p><p>　　自動變速器通過液力變矩器接受發(fā)動機(jī)動力，被發(fā)動機(jī)曲軸驅(qū)使。變換器的液壓允許動力從液力變矩器傳到變速器輸入軸。</p><p>　　輸入軸帶動行星齒輪副

61、提供不同的前進(jìn)擋，空擋和倒檔。通過傳動裝置的功率由盤式離合器，單片離合器和摩擦片控制。</p><p><b>　　B</b></p><p><b>　　液力變矩器</b></p><p>　　現(xiàn)代自動變速器的核心是液力變矩器。它代替了手動變速器的離合器來傳輸從發(fā)動機(jī)到變速器輸出軸的動力。液力變矩器提供了有利的成倍轉(zhuǎn)速動

62、力。</p><p>　　液力變矩器有三個部分幫助成倍提高動力：聯(lián)接在發(fā)動機(jī)曲軸上的葉輪，一個渦輪連接在齒輪上的渦輪軸和在兩者之間的導(dǎo)向輪。</p><p>　　液力變矩器里面充滿了變速器液體，那些液體被泵輪葉片驅(qū)動。當(dāng)葉輪旋轉(zhuǎn)到一定速度時，渦輪被葉輪帶動開始旋轉(zhuǎn)。</p><p><b>　　行星齒輪組</b></p><

63、p>　　行星齒輪組提供不同的齒輪傳動比，使汽車在正確的方向正確的速度上行駛。一個行星齒輪組由一個太陽輪，行星齒輪和一個齒圈組成。</p><p>　　行星齒輪組的中心是太陽輪。行星齒輪圍繞著太陽輪，就像我們的地球和其他行星在我們的太陽系。這些齒輪被安裝在行星齒輪架上而且每個齒輪都在獨(dú)立的軸上旋轉(zhuǎn)。行星齒輪是恒定不變的嚙合在太陽輪和齒圈上。齒圈是行星齒輪組遠(yuǎn)離中心的齒。</p><p>

64、;　　它有內(nèi)齒而且圍繞著其余的齒輪組。它的齒被恒定不變的嚙合在</p><p>　　行星齒輪上。許多星系齒輪根據(jù)變速器所設(shè)計面對的負(fù)荷來運(yùn)用在行星齒輪組上。對于高負(fù)荷，許多星系齒輪提高比內(nèi)齒更高的負(fù)荷來帶動工作。</p><p>　　星系齒輪組能夠提供一個齒輪減速或者齒輪超速，前進(jìn)擋或者倒檔，或者一個空擋。因?yàn)辇X輪固定不變的嚙合，變速齒輪被制造了而不再需要接合齒輪或者分離齒輪，它被運(yùn)用在手

65、動變速器上。相反，離合器被運(yùn)用的既要保持或者釋放不同的齒輪組數(shù)量又要獲得合適的旋轉(zhuǎn)度和齒輪比。</p><p><b>　　差速器</b></p><p>　　在前輪驅(qū)動汽車上，差速器裝置一般是變速驅(qū)動橋的部分組成。在后輪驅(qū)動橋上，它是后橋的組成部分。在差速器殼內(nèi)，是差速器行星齒輪軸，行星齒輪和差速器齒輪半軸。</p><p>　　差速器圍繞著

66、齒圈旋轉(zhuǎn)。輪軸邊上的齒輪用花鍵聯(lián)接在前橋驅(qū)動橋或者后橋驅(qū)動橋上。</p><p>　　當(dāng)一輛汽車一直往前走，它的輪子也是自由旋轉(zhuǎn)。引擎動力被運(yùn)用在行星齒輪，使它旋轉(zhuǎn)行星齒輪。斜行星齒輪被圍繞著齒圈旋轉(zhuǎn)就像一個整體在旋轉(zhuǎn)。各個車軸接收一樣的動力，所以各個車輪以一樣的速度旋轉(zhuǎn)。</p><p>　　當(dāng)汽車開到一個狹窄的角落，只有一個輪子自由地轉(zhuǎn)動。扭矩依然參與在行星齒輪間和齒圈間旋轉(zhuǎn)，并使斜齒

67、輪圍繞著它旋轉(zhuǎn)。然而，一個輪軸被固定著和一個斜齒輪被迫在他們的軸線上旋轉(zhuǎn)和在他們齒輪上“漫游”。另一邊被迫旋轉(zhuǎn)因?yàn)樗艿烬X輪旋轉(zhuǎn)的力量，這些力量通過小齒輪傳遞。</p><p><b>　　驅(qū)動軸</b></p><p>　　一個驅(qū)動軸和萬向節(jié)聯(lián)接了變速器與后輪傳動軸在大多數(shù)后輪驅(qū)動汽車上。許多四輪驅(qū)動汽車也用驅(qū)動軸和萬向節(jié)，用第一驅(qū)動軸放在分動器和后輪驅(qū)動軸間和第二