外文翻譯--手動變速器基礎(chǔ)

1 附 錄 附錄 A 英語科技文獻(xiàn) Manual Transmission Basics Its no secret that cars with manual transmissions are usually more fun to drive than their automatic-equipped counterparts. If you have even a passing interest in the act of driving, then chances are you also appreciate a fine-shifting manual gearbox. But how does a manual trans actually work? With our primer on automatics(or slushboxes, as detractors call them) available for your perusal, we thought it would be a good idea to provide a companion overview on manual trannies, too. A brief history lesson shows that manual transmissions preceded automatics by several decades. In fact, up until General Motors offered an automatic in 1938, all cars were of the shift-it-yourself variety. While its logical for many types of todays vehicles to be equipped with an automatic - such as a full-size sedan, SUV or pickup - the fact remains that nothing is more of a thrill to drive than a tautly suspended sport sedan, sport coupe or two-seater equipped with a precise-shifting five- or six-speed gearbox. Its what makes cars such as a Corvette, Mustang, Miata or any BMW sedan or coupe some of the most fun-to-drive cars available today. We know which types of cars have manual trannies. Now lets take a look at how they work. From the most basic four-speed manual in a car from the 60s to the most high-tech six-speed in a car of today, the principles of a manual gearbox are the same. The driver must shift from gear to gear. Normally, a manual transmission bolts to a clutch housing (or bell housing) that, in turn, bolts to the back of the engine. If the vehicle has front-wheel drive, the transmission still attaches to the engine in a similar fashion but is usually referred to as a transaxle. This is because the transmission, differential and drive axles are one complete unit. In a front-wheel-drive car, the transmission also serves as part of the front axle for the front wheels. In the remaining text, a transmission and transaxle will both be referred to using the term transmission. 2 The function of any transmission is transferring engine power to the driveshaft and rear wheels (or axle halfshafts and front wheels in a front-wheel-drive vehicle). Gears inside the transmission change the vehicles drive-wheel speed and torque in relation to engine speed and torque. Lower (numerically higher) gear ratios serve as torque multipliers and help the engine to develop enough power to accelerate from a standstill. Initially, power and torque from the engine comes into the front of the transmission and rotates the main drive gear (or input shaft), which meshes with the cluster or counter shaft gear - a series of gears forged into one piece that resembles a cluster of gears. The cluster-gear assembly rotates any time the clutch is engaged to a running engine, whether or not the transmission is in gear or in neutral. There are two basic types of manual transmissions. The sliding-gear type and the constant-mesh design. With the basic - and now obsolete - sliding-gear type, nothing is turning inside the transmission case except the main drive gear and cluster gear when the trans is in neutral. In order to mesh the gears and apply engine power to move the vehicle, the driver presses the clutch pedal and moves the shifter handle, which in turn moves the shift linkage and forks to slide a gear along the mainshaft, which is mounted directly above the cluster. Once the gears are meshed, the clutch pedal is released and the engines power is sent to the drive wheels. There can be several gears on the mainshaft of different diameters and tooth counts, and the transmission shift linkage is designed so the driver has to unmesh one gear before being able to mesh another. With these older transmissions, gear clash is a problem because the gears are all rotating at different speeds. All modern transmissions are of the constant-mesh type, which still uses a similar gear arrangement as the sliding-gear type. However, all the mainshaft gears are in constant mesh with the cluster gears. This is possible because the gears on the mainshaft are not splined to the shaft, but are free to rotate on it. With a constant-mesh gearbox, the main drive gear, cluster gear and all the mainshaft gears are always turning, even when the transmission is in neutral. Alongside each gear on the mainshaft is a dog clutch, with a hub thats positively splined to the shaft and an outer ring that can slide over against each gear. Both the mainshaft gear and the ring of the dog clutch have a row of teeth. Moving the shift linkage 3 moves the dog clutch against the adjacent mainshaft gear, causing the teeth to interlock and solidly lock the gear to the mainshaft. To prevent gears from grinding or clashing during engagement, a constant-mesh, fully synchronized manual transmission is equipped with synchronizers. A synchronizer typically consists of an inner-splined hub, an outer sleeve, shifter plates, lock rings (or springs) and blocking rings. The hub is splined onto the mainshaft between a pair of main drive gears. Held in place by the lock rings, the shifter plates position the sleeve over the hub while also holding the floating blocking rings in proper alignment. Thats the basics on the inner workings of a manual transmission. As for advances, they have been extensive over the years, mainly in the area of additional gears. Back in the 60s, four-speeds were common in American and European performance cars. Most of these transmissions had 1:1 final-drive ratios with no overdrives. Today, overdriven five-speeds are standard on practically all passenger cars available with a manual gearbox. Overdrive is an arrangement of gearing that provides more revolutions of the driven shaft (the driveshaft going to the wheels) than the driving shaft (crankshaft of the engine). For example, a transmission with a fourth-gear ratio of 1:1 and a fifth-gear ratio of 0.70:1 will reduce engine rpm by 30 percent, while the vehicle maintains the same road speed. Thus, fuel efficiency will improve and engine wear will be notably reduced. Today, six-speed transmissions are becoming more and more common. One of the first cars sold in America with a six-speed was the 89 Corvette. Designed by Chevrolet and Zahnradfabrik Friedrichshafen (ZF) and built by ZF in Germany, this tough-as-nails six-speed was available in the Corvette up to the conclusion of the 96 model year. Today, the Corvette uses a Tremec T56 six-speed mounted at the back of the car. Many cars are available today with six-speeds, including the Mazda Miata, Porsche Boxster S and 911, Dodge Viper, Mercedes-Benz SLK350, Honda S2000, BMW 3-Series and many others. Some of these gearboxes provide radical 50-percent (0.50:1) sixth-gear overdrives such as in the Viper and Corvette, while others provide tightly spaced gear ratios like in the S2000 and Miata for spirited backroad performance driving. While the bigger cars mentioned above such as the Viper and Vette often have two overdrive ratios (fifth and sixth) the smaller cars like the Celica and S2000 usually have one overdriven gear ratio (sixth) and fifth is 1:1. 4 Clearly a slick-shifting manual transmission is one of the main components in a fun-to-drive car, along with a powerful engine, confidence-inspiring suspension and competent brakes. For more information on a manual transmissions primary partner component, check out our basic primer on clutches and clutch operation. 5 附錄 B 文獻(xiàn)翻譯 手動變速器基礎(chǔ) 汽車手動變速器相比于自動變速器的駕駛裝備來說，在駕駛方面擁有更多的樂趣，這已不再是什么秘密了。如果你有興趣超速駕駛，那么，你會贊賞對手動變速器汽車的超速進(jìn)行罰款。但是，手動擋變速器汽車是如何工作的？我們將原始的自動檔變速器（或 slushboxex,因為反對者這樣稱呼他們）提供給您審閱，我們認(rèn)為將一個概述手冊提供給 合作伙伴是一個好主意。 簡明的歷史教訓(xùn)表明，自從有了手動變速器，幾十年間，事實上，直至 1938年通用汽車才開發(fā)了自動變速器。所有汽車才有了改變車型的想法。現(xiàn)在多種類型的汽車上配備了自動變速器，雖然這是合乎邏輯的，例如，全尺寸轎車，越野車或皮卡。但事實上，相對于落后的運動轎車，沒有比這更刺激的駕駛樂趣了。運動跑車或兩個座位的跑車配備了精確地五檔或六檔變速器，這是為什么使得汽車如克爾維特，野馬Miata或任何寶馬轎車或跑車強(qiáng)調(diào)駕駛樂趣的汽車上市的原因了。 我們知道一些類型的汽車手冊，現(xiàn)在讓我們看看他們?nèi)绾喂ぷ鳌?從六十年代最基本的四檔手動變速器汽車到今天的高科技六檔手動變速器汽車，這些手動檔變速器的原理是一樣的。駕駛者換擋是從一個齒輪到另一個齒輪，正常情況下，手動變速器螺栓連接離合器殼，而離合器殼的另一面通過螺栓與發(fā)動機(jī)后部相連。如果車輛是前輪驅(qū)動的汽車，變速器仍然以同樣的方式連接發(fā)動機(jī)，通常稱之為橋。這是因為變速器，差速器和驅(qū)動橋是一個完整的單元。前輪驅(qū)動的汽車變速器用于驅(qū)動前軸上的前輪。在下面的文章里，變速器和驅(qū)動橋都將提到并使用它。 所有變速器的功能都是傳遞發(fā)動機(jī)的動力給后驅(qū)動輪（或前驅(qū)動輪）。變速器內(nèi)部的齒 輪傳動改變車輛的速度和扭矩，它與發(fā)動機(jī)的轉(zhuǎn)速和扭矩有關(guān)。低（數(shù)值高）傳動比用于多種扭矩，它能夠幫助發(fā)動機(jī)獲得足夠的動力，用以加速或停車。 起初，功率和扭矩從發(fā)動機(jī)的前端傳遞和旋轉(zhuǎn)至主傳動齒輪（或輸入軸）。其中，嚙合的從動齒輪或中間軸齒輪 -一系列齒輪鍛造成一個類似于一組齒輪。在任何時候，從動齒輪都處于旋轉(zhuǎn)狀態(tài)，離合器在一個運行的引擎作用下運行，無論是在齒輪傳動或是處于空擋。 有兩種基本類型的手動檔變速器?；瑒育X輪式和常嚙合齒輪式。和基本的一樣 -6 現(xiàn)在已經(jīng)過時 -滑動齒輪類型，當(dāng)檔位處于空擋時，沒 有什么使傳動箱內(nèi)除了主傳動齒輪及齒輪組轉(zhuǎn)動。為了使嚙合的齒輪適用于發(fā)動機(jī)的功率以驅(qū)動車輛，駕駛者踩踏離合器踏板和移動變速器操縱桿，這使得換擋拉線和撥叉促使齒輪沿主軸方向滑動，這就是直接換擋。一旦齒輪嚙合，離合器踏板釋放，發(fā)動機(jī)功率傳遞到驅(qū)動車輪?？赡苡袔讉€在不同軸頸上的齒輪和齒，變速器的換擋杠桿機(jī)構(gòu)是被設(shè)計用來方便駕駛員換擋的機(jī)構(gòu)。這些過時的變速器，齒輪的碰撞是一個問題，因為齒輪都以不同的速度旋轉(zhuǎn)。 所有的現(xiàn)代變速器都是常嚙合齒輪式，它仍然使用了類似的布置，齒輪滑動齒輪類型。然而，所有的主動齒輪與從動齒輪嚙 合，這是因為齒輪的主軸不以花鍵軸的形