机械毕业设计英文外文翻译444手动变速器如何工作
手动变速器的工作原理详述
手动变速器的工作原理详述手动变速器是一种常见的汽车传动装置，它允许驾驶者在行驶过程中手动选择合适的挡位以改变车辆的速度和扭矩输出。
本文将详细介绍手动变速器的工作原理，从齿轮机构、离合器和操作杆三个方面进行阐述。
一、齿轮机构手动变速器的齿轮机构是实现挡位切换和传动功能的核心部件。
它由一系列平行轴的齿轮组成。
不同挡位的选择会使得不同的齿轮组合在一起，实现不同的变速比。
常见的手动变速器包括常用的H型齿轮机构和X型齿轮机构。
H型齿轮机构具有三个轴和四个齿轮，分别代表着一、二、三挡和倒挡。
当驾驶员通过操作杆将换挡叉推动到相应的位置时，离合器断开连接，该挡位所需的齿轮组合将被锁定在传动轴上，从而实现对应的挡位功能。
X型齿轮机构相较于H型齿轮机构增加了一个轴和一个齿轮，因此可以实现更多的挡位选择。
通过操作杆将换挡叉推动到相应的位置，离合器断开连接，特定的齿轮组合将被锁定在传动轴上。
二、离合器离合器是手动变速器与发动机之间的连接器件，它的主要作用是在挂挡和起步时使发动机与变速器分离，从而实现平稳的换挡和起步动作。
离合器通常由驱动盘、驱动轴和压力盘组成。
在起步阶段，当驾驶员踩下离合器踏板时，压力盘与驱动盘分离，使发动机的动力不能传递给变速器，车辆处于空挡状态。
当驾驶员松开离合器踏板时，压力盘和驱动盘通过离合器压盘弹簧的作用重新连接，发动机的动力通过离合器传递到变速器，车辆开始运动。
三、操作杆操作杆是手动变速器的操控装置，它与变速器的换挡叉相连，通过向前或向后推动操作杆来选择不同的挡位。
操作杆的设计通常采用直杆式或者弧形杆式，以便驾驶员能够准确选择不同的挡位。
当操作杆推动到前方时，齿轮机构会切换到高挡位或者变速器空挡状态；当操作杆推动到后方时，齿轮机构会切换到低挡位或者倒挡状态。
通过掌握操作杆的使用方法，驾驶员可以根据道路条件和行驶速度选择合适的挡位，以实现平稳的加速或降速。
结论手动变速器通过齿轮机构、离合器和操作杆的相互配合，实现了驾驶员对汽车的速度调节和扭矩输出的控制。
手动变速器基础外文文献翻译、中英文翻译、外文翻译
中国地质大学长城学院本科毕业设计外文资料翻译系别：工程技术系专业：机械设计制造及其自动化姓名：黄昌照学号：052115322015 年4月7日Manual Transmission BasicsIt's 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 it's logical for many types of today's 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. It's 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 let's 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.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 thetransmission change the vehicle's 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 engine's 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 that's 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 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.That's 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.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 andcompetent brakes. For more information on a manual transmission's primary partner component, check out our basic primer on clutches and clutch operation.附录B 文献翻译手动变速器基础汽车手动变速器相比于自动变速器的驾驶装备来说，在驾驶方面拥有更多的乐趣，这已不再是什么秘密了。
外文翻译：手动变速器概述
Manual transmissionManual transmission is the most basic of transmission of a type, its effect is changing, and provide the transmission reverse and neutral. Usually, the pilot on the clutch pedal through manipulation and in any HuanDangGan can choose between gear. There are a few manual transmission, such as motorcycles, cars, some transmission shift transmission allows only sequence, the transmission is called sequence shift transmission. In recent years, along with the electronic control components durability, computerized automatic switching clutch automatic shift of transmission in Europe since the start line are more and more popular, car V olkswagen and ford are sold in the city on the double clutch provide updated generation, transmission from the start with two clutches, every shift automatically switch to another group of clutch engagement, need not as quick as traditional in manual have only one group separated again clutch engagement, shifting speed is faster, more small change gear vibration.Internal structure: shaftDecorate a form of transmission shaft type usually have two and three shaft type two kinds. Usually a rear wheel drive car will adopt three axis type, i.e. input shaft transmission, the output shaft and oart. Input shaft front associated with engine, borrow clutch output shaft back-end through the flange and universal transmission device connected.Input shaft and the output shaft in the same horizontal line, with their oart parallel arrangement. From the input shaft power through the gears to preach to the output shaft oart again. In many input and output shaft transmission shaft could engage in together, so to power, then the gear oart called directly. Direct files through uniaxial transmission, the ratio of 1:1, the highest transmission efficiency. Even in the transmission directly, cannot offer the input shaft, and the output shaft is decorated in a straight line to reduce work needed to inherit the torque transmission.Reversing deviceGenerally speaking, the reverse gear reducer than can alsosynchronizerIn synchronized meshing gears have type synchronizer Settings, can make two gear engagement in the first, before the speed reached synchronizer in all of this manual geartransmission of the car has been usedClutch,The clutch is can make two gear with a separate with mechanical parts, two gear transmission power can be combined, but when to speed, so will depend on the first two gear clutch, change gear ratio, the two gear transmission power, continue again Control：GearIn simple terms, the high speed, low speed ShengDang when the time cameEvery car high speedCompared with automatic transmissionThis refers to the automatic transmission of traditional hydraulic transmission, namely through hydraulic torque converter and planetary gear transmission power automatic transmission.Advantages：transmission efficiency than automatic gearboxes for high, of course, theoretically can compare economical.maintenance will be cheaper than transmission.If you want to higher cost, can begin from both the row of convenience and high power手动变速器手动变速器是汽车变速器中最基本的一种类型，其作用是改变传动比，并提供倒档和空档。
车辆工程专业外文翻译自动变速器如何工作
How Automatic Transmissions WorkIf you have ever driven a car with an automatic transmission, then you know that there are two big differences between an automatic transmission and a manual transmission:There is no clutch pedal in an automatic transmission car.There is no gear shift in an automatic transmission car. Once you put the transmission into drive, everything else is automatic.Both the automatic transmission (plus its torque converter) and a manual transmission (with its clutch) accomplish exactly the same thing, but they do it in totally different ways. It turns out that the way an automatic transmission does it is absolutely amazing!In this article, we'll work our way through an automatic transmission. We'll start with the key to the whole system: planetary gear sets. Then we'll see how the transmission is put together, learn how the controls work and discuss some of the intricacies involved in controlling a transmission.Some BasicsJust like that of a manual transmission, the automatic transmission's primary job is to allow the engine to operate in its narrow range of speeds while providing a wide range of output speeds.Without a transmission, cars would be limited to one gear ratio, and that ratio would have to be selected to allow the car to travel at the desired top speed. If you wanted a top speed of 80 mph, then the gear ratio would be similar to third gear in most manual transmission cars.You've probably never tried driving a manual transmission car using only third gear. If you did, you'd quickly find out that you had almost no acceleration when starting out, and at high speeds, the engine would be screaming along near the red-line. A car like this would wear out very quickly and would be nearly undrive able.So the transmission uses gears to make more effective use of the engine's torque, and to keep the engine operating at an appropriate speed.The key difference between a manual and an automatic transmission is that the manual transmission locks and unlocks 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 the different gear ratios. The planetary gear set is the device that makes this possible in an automatic transmission.GearsThis automatic transmission uses a set of gears, called a compound planetary gear set, that looks like a single planetary gear set but actually behaves like twoplanetary gear sets combined. It has one ring gear that is always the output of the transmission, but it has two sun gears and two sets of planets.Let's look at some of the parts:First GearIn first gear, the smaller sun gear is driven clockwise by the turbine in the torque converter. The planet carrier tries to spin counterclockwise, but is heldstill by the one-way clutch (which only allows rotation in the clockwise direction) and the ring gear turns the output. The small gear has 30 teeth and the ring gear has 72, so the gear ratio is:Ratio = -R/S = - 72/30 = -2.4:1So the rotation is negative 2.4:1, which means that the output direction would be opposite the input direction. But the output direction is really the same as the input direction -- this is where the trick with the two sets of planets comes in. The first set of planets engages the second set, and the second set turns the ring gear; this combination reverses the direction. You can see that this would also cause the bigger sun gear to spin; but because that clutch is released, the bigger sun gear is free to spin in the opposite direction of the turbineSecond GearThis transmission does something really neat in order to get the ratio needed for second gear. It acts like two planetary gear sets connected to each other with a common planet carrier.The first stage of the planet carrier actually uses the larger sun gear as the ring gear. So the first stage consists of the sun (the smaller sun gear), the planet carrier, and the ring (the larger sun gear).The input is the small sun gear; the ring gear (large sun gear) is held stationary by the band, and the output is the planet carrier. so the formula is:1 + R/S = 1 + 36/30 = 2.2:1The planet carrier turns 2.2 times for each rotation of the small sun gear. At the second stage, the planet carrier acts as the input for the second planetary gear set, the larger sun gear (which is held stationary) acts as the sun, and the ring gear acts as the output, so the gear ratio is:1 / (1 + S/R) = 1 / (1 + 36/72) = 0.67:1To get the overall reduction for second gear, we multiply the first stage by the second, 2.2 x 0.67, to get a 1.47:1 reduction. This may sound wacky, but it works.Third GearMost automatic transmissions have a 1:1 ratio in third gear. You'll remember from the previous section that all we have to do to get a 1:1 output is lock together any two of the three parts of the planetary gear. With the arrangement in this gear set it is even easier -- all we have to do is engage the clutches that lock each of the sun gears to the turbine.If both sun gears turn in the same direction, the planet gears lockup becausethey can only spin in opposite directions. This locks the ring gear to the planets and causes everything to spin as a unit, producing a 1:1 ratio. OverdriveBy definition, an overdrive has a faster output speed than input speed. It's a speed increase. In this transmission, engaging the overdrive accomplishes two things at once. If you read How Torque Converters Work, you learned about lockup torque converters. In order to improve efficiency, some cars have a mechanism that locks up the torque converter so that the output of the engine goes straight to the transmission.In this transmission, when overdrive is engaged, a shaft that is attached to the housing of the torque converter (which is bolted to the flywheel of the engine) is connected by clutch to the planet carrier. The small sun gear freewheels, and the larger sun gear is held by the overdrive band. Nothing is connected to the turbine; the only input comes from the converter housing. Let's go back to our chart again, this time with the planet carrier for input, the sun gear fixed and the ring gear for output.Ratio = 1 / (1 + S/R) = 1 / ( 1 + 36/72) = 0.67:1So the output spins once for every two-thirds of a rotation of the engine. If the engine is turning at 2000 rotations per minute (RPM), the output speed is 3000 RPM. This allows cars to drive at freeway speed while the engine speed stays nice and slow.ReverseReverse is very similar to first gear, except that instead of the small sun gear being driven by the torque converter turbine, the bigger sun gear is driven, and the small one freewheels in the opposite direction. The planet carrier is held by the reverse band to the housing. So, according to our equations from the last page, we have:Ratio = -R/S = 72/36 = 2.0:1So the ratio in reverse is a little less than first gear in this transmission. Gear RatiosThis transmission has four forward gears and one reverse gear. Let's summarize the gear ratios, inputs and outputs:Hydraulic SystemThe automatic transmission in your car has to do numerous tasks. You may not realize how many different ways it operates. For instance, here are some of the features of an automatic transmission:∙If the car is in overdrive (on a four-speed transmission), the transmission will automatically select the gear based on vehicle speed and throttlepedal position.∙If you accelerate gently, shifts will occur at lower speeds than if you accelerate at full throttle.∙If you floor the gas pedal, the transmission will downshift to the next lower gear.∙If you move the shift selector to a lower gear, the transmission will downshift unless the car is going too fast for that gear. If the car is goingtoo fast, it will wait until the car slows down and then downshift.∙If you put the transmission in second gear, it will never downshift or up shift out of second, even from a complete stop, unless you move the shiftlever.∙You've probably seen something that looks like this before. It is really the brain of the automatic transmission, managing all of these functionsand more. The passageways you can see route fluid to all the differentcomponents in the transmission. Passageways molded into the metal arean efficient way to route fluid; without them, many hoses would be needed to connect the various parts of the transmission. First, we'll discuss thekey components of the hydraulic system; then we'll see how they worktogether.The PumpAutomatic transmissions have a neat pump, called a gear pump. The pump is usually located in the cover of the transmission. It draws fluid from a sump in the bottom of the transmission and feeds it to the hydraulic system. It also feeds the transmission cooler and the torque converter.The inner gear of the pump hooks up to the housing of the torque converter, so it spins at the same speed as the engine. The outer gear is turned by the inner gear, and as the gears rotate, fluid is drawn up from the sump on one side of the crescent and forced out into the hydraulic system on the other side.The GovernorThe governor is a clever valve that tells the transmission how fast the car is going. It is connected to the output, so the faster the car moves, the faster the governor spins. Inside the governor is a spring-loaded valve that opens in proportion to how fast the governor is spinning -- the faster the governor spins, the more the valve opens. Fluid from the pump is fed to the governor through the output shaft.The faster the car goes, the more the governor valve opens and the higher the pressure of the fluid it lets through.Valves and ModulatorsThrottle Valve or ModulatorTo shift properly, the automatic transmission has to know how hard the engine is working. There are two different ways that this is done. Some cars have a simple cable linkage connected to a throttle valve in the transmission. The further the gas pedal is pressed, the more pressure is put on the throttle valve. Other cars use a vacuum modulator to apply pressure to the throttle valve. The modulator senses the manifold pressure, which drops when the engine is under a greater load.Manual ValveThe manual valve is what the shift lever hooks up to. Depending on which gear is selected, the manual valve feeds hydraulic circuits that inhibit certain gears. For instance, if the shift lever is in third gear, it feeds a circuit that prevents overdrive from engaging.Shift ValvesShift valves supply hydraulic pressure to the clutches and bands to engage each gear. The valve body of the transmission contains several shift valves. The shift valve determines when to shift from one gear to the next. For instance, the 1 to 2 shift valve determines when to shift from first to second gear. The shift valve is pressurized with fluid from the governor on one side, and the throttle valve on the other. They are supplied with fluid by the pump, and they route that fluid to one of two circuits to control which gear the car runs in.The shift valve will delay a shift if the car is accelerating quickly. If the car accelerates gently, the shift will occur at a lower speed. Let's discuss what happens when the car accelerates gently.As car speed increases, the pressure from the governor builds. This forces the shift valve over until the first gear circuit is closed, and the second gear circuit opens. Since the car is accelerating at light throttle, the throttle valve does not apply much pressure against the shift valve.When the car accelerates quickly, the throttle valve applies more pressure against the shift valve. This means that the pressure from the governor has to be higher (and therefore the vehicle speed has to be faster) before the shift valve moves over far enough to engage second gear.Each shift valve responds to a particular pressure range; so when the car is going faster, the 2-to-3 shift valve will take over, because the pressure from the governor is high enough to trigger that valve.Electronic ControlsElectronically controlled transmissions, which appear on some newer cars, still use hydraulics to actuate the clutches and bands, but each hydraulic circuit is controlled by an electric solenoid. This simplifies the plumbing on the transmission and allows for more advanced control schemes.自动变速器如何工作如果你曾经驾驶过一辆带着自动变速器的车, 那么你就知道自动变速器和手动变速器之间有很大的不同:在一个带着自动变速器的汽车中没有离合器踏板。
24 机械工程英语 学生工作页：手动变速器的工作
总结知识点
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类别
比例
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成果评定
根据学习成果评定成绩，占 60％
学生自评
学生根据对执行任务过程进行自评，给出相应的成绩，占10％
学生互评
学生间根据课堂口语表达及表现，互相评价，占10％
教师评价
教师根据对学生的学习态度、出勤率、课堂表现、沟通与表达能力，并结合执行任务过程的各个环节进行评价，占20％
任务2：Two types of transmission are the manual and the automatic .
任务3：The gear shift mechanism consists of a lever, shift forks shaft, shift forks, locks and a reverse speed safety device.
合计
3）具备表达能力、团结协作能力、计划组织能力等职业素养。
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资讯学习及任务执行
Ⅰ.The work of manual transmission(Textexplanation)
资讯1：device[dɪˈvaɪs]n.装置，设备
任务1：A transmission is a speed and power changing device installed at some point between the engine and driving wheels of the vehicle. Two types of transmission are the manual and the automatic.
外文翻译-手动变速器
附录附录A.Manual TransmissionIt’s no secret that cars with manual transmissions are usually more fun to drive than the 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 transmission actually work?A history hows 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 it’s logical for many types of today’s 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, snort coupe or two-sealer equipped with a precise-shifting five-or six-speed gearbox．We know whicn types or cars have manual trannies. Now let’s take a loo k at how they work. From the most basic four-speed manual in a car from the’60s to the most high-tech six-speed one 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）, 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 a transaxle will both be referred to using the term transmission.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 vehicle’s 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 transmissions and rotates the main drive gear (or input shaft), which meshes with the cluster or countersha ft 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 clust er. Once the gears are meshed, the clutch pedal is released and the engine’s 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 that’s 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 shift linkage 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.A synchro’s inner hub and sleeve are made of steel, but the blocking ring――the partof the synchro that rubs on the gear to change its speed――is usually made of a softer material, such as brass. The blocking ring has teeth that match the teeth on the dog clutch. Most synchros perform double duty――they push the synchro in one direction and lock one gear to the mainshaft. Push the synchro the other way and it disengages from the first gear, passes through a neutral position, and engages a gear on the other side.That’s 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 60’s, 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. D esigned 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 SLK320, Honda S2000, Toyota Celica GT-S 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 Celica 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.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.附录B.手动变速器相对于自动变速箱的车手动变速箱汽车开起来有更好的驾驶乐趣这是众所周知的。
手动变速器工作原理
手动变速器工作原理手动变速器是一种用于汽车和其他机械设备上的传动装置，它允许驾驶员通过改变齿轮的比例来更改车辆的速度和扭矩输出。
手动变速器主要由离合器、齿轮、齿轮轴和选择机构组成。
在这篇文章中，我们将详细介绍手动变速器的工作原理。
手动变速器有多个齿轮，每个齿轮的大小和齿数都不相同。
这些齿轮通过齿轮轴彼此相连。
当驾驶员操作变速杆时，选择机构将根据驾驶员的选择移动齿轮，从而改变齿轮之间的连接方式。
这种改变会导致不同的齿轮比例，进而影响车辆的输出扭矩和速度。
变速器的工作原理可以从离合器开始介绍。
离合器是连接发动机和变速器的装置，它允许驾驶员在不停止发动机的情况下换挡。
离合器由离合器盘、压盘和离合器轴承组成。
当驾驶员踩下离合器踏板时，压盘与离合器盘之间的压力消除，离合器盘与发动机之间断开连接，发动机的转动不会传递到变速器。
当驾驶员松开离合器踏板时，压盘与离合器盘之间的压力增加，离合器盘与发动机重新连接起来，发动机的转动就会传递到变速器。
对于手动变速器，不同的齿轮组合会产生不同的变速比。
变速比是指发动机转动一圈，车轮转动的圈数。
较高的变速比意味着发动机转动更多圈才能使车轮转动一圈，这会产生更大的扭矩输出，但速度会相应降低。
相反，较低的变速比意味着发动机转动较少圈数使车轮转动一圈，这会产生更高的速度，但扭矩可能会减小。
在手动变速器中，常见的齿轮组合包括一、二、三、四挡和倒挡。
一挡通常被用于起步，它使用最小的齿轮比例，提供最大的扭矩输出，但速度相对较低。
二、三和四挡则用于不同的行驶速度范围，随着挡位的增加，齿轮比例逐渐增大，扭矩输出相应减小，速度逐渐增加。
倒挡用于倒车时，将齿轮反向旋转，让车辆向后移动。
在驾驶过程中，驾驶员通过变速杆选择不同的挡位。
变速杆控制选择机构，选择机构则将变速杆的动作传递给相应的齿轮。
选择机构通常由一组齿轮和滑块组成。
当驾驶员移动变速杆时，滑块会滑动到相应的齿轮上，使其与其他齿轮相连或断开。
汽车变速器的设计外文文献翻译、中英文翻译、外文翻译
本科毕业设计（论文）英文资料翻译*****指导教师：孙飞豹（副教授）学科、专业：车辆工程沈阳理工大学应用技术学院2011年12月20日transmission used in automobilesA standard transmission or manual transmission is the traditional type of transmission used in automobiles. The manual or standard transmission consists of a series of gears, synchros, roller bearings, shafts and gear selectors. The main clutch assembly is used to engage and disengage the engine from the transmission. Heliacal cut gears are used to select the ratio desired the sector fork move gears from one to another by using the gearshift knob. Synchros are used to slow the gear to a stop before it is engaged to avoid gear grinding, the counter shaft hold the gears in place and against the main input and output shaft. A stick shift transmission has no torque converter so there is no need for a transmission cooler. A stick shift transmission needs a simple fluid change for proper service. (there is no transmission filter in a stick shift transmission).Transmission ShifterMost manual transmissions have one reverse gear and four to six forward gears. Some cars also have eight forward gears while thirteen to twenty-four gears are present in semi trucks. To differentiate among the available standard transmissions, they are addressed by the number of forward gears. For example, if the standard transmission has five gears, it will be referred to as 5-speed standard transmission or 5-speed standard.Typical Standard Transmission ConfigurationInside the transmission shafts contain all forward and reverse gears. Most transmissions contain three shafts: input shaft, output shaft and counter or lay shaft. Other than standard transmission, there are other transmissions like continuously variable transmission, automatic transmission and semi-automatic transmission. In the manual transmission, a pair of gears inside the transmission selects the gear ratios. Whereas, in an automatic transmission, combination of brake bands and clutch packs control the planetary gear which selects the gear ratio.If there is a provision to select a gear ratio manually in automatic transmissions, the system is called a semi-automatic transmission. The driver can select from any of the gears at any pointof time. In some automobiles like racing cars and motorcycles that have standard transmissions, the driver can select the preceding or the following gear ratio with no clutch operation needed. This type of standard transmission is known as sequential transmission. In this transmission the clutch is still used for initial take off.Clutch and Flywheel AssemblyThe main clutch plays the role of a coupling device which separates the transmission and the engine. If the clutch is absent and the car comes to a stop the engine will stall. In automobiles, the clutch can be operated with the help of a pedal located on the floor of the vehicle. In an automatic transmission instead of a clutch, a torque converter is used to separate the transmission and engine.Typical Stick Shift PatternsA desired gear can be selected by a lever which is usually located on the floor in between the driver and passenger seat. This selector lever is called the gear lever or gear selector or gear shift or shifter. This gear stick can be made to move in right, left, forward and backward direction. When the gear is placed on the N position or neutral position, no gear will be selected. To move the car in the backward direction, the R gear or reverse gear should be selected.Standard transmissions are more efficient and less expensive to produce than automatic transmissions. A Standard transmission is about 15% more efficient compared to an automatic transmission. Standard transmissions are generally stronger than automatic transmissions and off road vehicles take advantage of a direct gear selection so they can withstand rough conditions. Less active cooling is also required in manual transmission system because less power is wasted.●Popular Problem ChecksCar will not go into gearClutch disc is broken completelyInternal transmission damageFailed clutch master cylinderSeized clutch slave cylinderBroken clutch fork pivotBroken clutch cableCar goes into gear but it fades out or is slippingClutch is worn out and needs replacementClutch is oil soaked from a external engine oil leakCar makes grinding noise while operating or shifting gearsOne of the roller or thrust bearings has failedThe gear synchro is worn out not forcing the gear stop before it is engaged causing a grinding gear.A counter or main shaft bearing has failed causing misalignment of the gears●Troubleshooting Noise and ProblemsIf the vehicle is running and a whirring sound is heard, then it goes away when the clutch is depressed, the transmission input bearing has failed.If the transmission is quiet in neutral but when you depress the clutch a squeaking noise is observed, a clutch throw out bearing has failed.Tips:Never let little noises go unattended; a small noise can cause a large noise and transmission operation failure. Never overload a vehicle or tow beyond the capacity this can cause premature transmission failure.汽车变速器汽车传统变速器是那种标准的手动变速器。
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附录How Manual Transmissions WorkIf you drive a stick-shift car, then you may have several questions floating in your head.How does the funny "H" pattern that I am moving this shift knob through have any relation to the gears inside the transmission? What is moving inside the transmission when I move the shifter?When I mess up and hear that horrible grinding sound, what is actually grinding? What would happen if I were to accidentally shift into reverse while I am speeding down the freeway? Would the entire transmission explode?In this article, we'll answer all of these questions and more as we explore the interior of a manual transmission.Cars need transmissions because of the physics of the gasoline engine. First, any engine has a redline --a maximum rpm value above which the engine cannot go without exploding. Second, if you have read How Horsepower Works, then you know that engines have narrow rpm ranges where horsepower and torque are at their maximum. For example, an engine might produce its maximum horsepower at 5,500 rpm. The transmission allows the gear ratio between the engine and the drive wheels to change as the car speeds up and slows down. You shift gears so the engine can stay below the redline and near the rpm band of its best performance.Ideally, the transmission would be so flexible in its ratios that the engine could always run at its single, best-performance rpm value. That is the idea behind the continuously variable transmission (CVT).A CVT has a nearly infinite range of gear ratios. In the past, CVTs could not compete with four-speed and five-speed transmissions in terms of cost, size and reliability, so you didn't see them in production automobiles. These days, improvements in design have made CVTs more common. The Toyota Prius is a hybrid car that uses a CVT.The transmission is connected to the engine through the clutch. The input shaft of the transmission therefore turns at the same rpm as the engine.A five-speed transmission applies one of five different gear ratios to the input shaft toproduce a different rpm value at the output shaft.A Very Simple TransmissionTo understand the basic idea behind a standard transmission, the diagram below shows a very simple two-speed transmission in neutral:Let's look at each of the parts in this diagram to understand how they fit together:The green shaft comes from the engine through the clutch. The green shaft and green gear are connected as a single unit. (The clutch is a device that lets you connect and disconnect the engine and the transmission. When you push in the clutch pedal, the engine and the transmission are disconnected so the engine can run even if the car is standing still. When you release the clutch pedal, the engine and the green shaft are directly connected to one another. The green shaft and gear turn at the same rpm as the engine.) The red shaft and gears are called the layshaft. These are also connected as a single piece, so all of the gears on the layshaft and the layshaft itself spin as one unit. The green shaft and the red shaft are directly connected through their meshed gears so that if the green shaft is spinning, so is the red shaft. In this way, the layshaft receives its power directly from the engine whenever the clutch is engaged.The yellow shaft is a splined shaft that connects directly to the drive shaft through the differential to the drive wheels of the car. If the wheels are spinning, the yellow shaft is spinning.The blue gears ride on bearings, so they spin on the yellow shaft. If the engine is offbut the car is coasting, the yellow shaft can turn inside the blue gears while the blue gears and the layshaft are motionless.Now, let's see what happens when you shift into first gear.First GearIn this picture, the green shaft from the engine turns the layshaft, which turns the blue gear on the right. This gear transmits its energy through the collar to drive the yellow drive shaft. Meanwhile, the blue gear on the left is turning, but it is freewheeling on its bearing so it has no effect on the yellow shaft.When the collar is between the two gears (as shown in the first figure), the transmission is in neutral. Both of the blue gears freewheel on the yellow shaft at the different rates controlled by their ratios to the layshaft.From this discussion, you can answer several questions:When you make a mistake while shifting and hear a horrible grinding sound, you are not hearing the sound of gear teeth mis-meshing. As you can see in these diagrams, all gear teeth are all fully meshed at all times. The grinding is the sound of the dog teeth trying unsuccessfully to engage the holes in the side of a blue gear.The transmission shown here does not have "synchros" (discussed later in the article), so if you were using this transmission you would have to double-clutch it. Double-clutching was common in older cars and is still common in some modern race cars. In double-clutching, you first push the clutch pedal in once to disengage the engine from the transmission. This takes the pressure off the dog teeth so you can move the collar into neutral. Then you release the clutch pedal and rev the engine to the "right speed." The right speed is the rpm value at which the engine should be running in the next gear. The idea is to get the blue gear of the next gear and the collar rotating at the same speed so that the dog teeth can engage. Then you push the clutch pedal in again and lock the collar into the new gear. At every gear change you have to press and release the clutch twice, hence the name "double-clutching."You can also see how a small linear motion in the gear shift knob allows you to change gears. The gear shift knob moves a rod connected to the fork. The fork slides the collar on the yellow shaft to engage one of two gears.In the next section, we'll take a look at a real transmission.A Real TransmissionThere are three forks controlled by three rods that are engaged by the shift lever. Looking at the shift rods from the top, they look like this in reverse, first and second gear: Keep in mind that the shift lever has a rotation point in the middle. When you push the knob forward to engage first gear, you are actually pulling the rod and fork for first gear back.You can see that as you move the shifter left and right you are engaging different forks (and therefore different collars). Moving the knob forward and backward moves the collar to engage one of the gears。