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1、附 录Manual transmission Overview Manual transmissions often feature a driver-operated clutch and a movable gear selector. Most automobile manual transmissions allow the driver to select any forward gear ratio (gear) at any time, but some, such as those commonly mounted on motorcycles and some types o
2、f racing cars, only allow the driver to select the next-higher or next-lower gear. This type of transmission is sometimes called a sequential manual transmission. Sequential transmissions are commonly used in auto racing for their ability to make quick shifts.Manual transmissions are characterized b
3、y gear ratios that are selectable by locking selected gear pairs to the output shaft inside the transmission. Conversely, most automatic transmissions feature epicyclic (planetary) gearing controlled by brake bands and/or clutch packs to select gear ratio. Automatic transmissions that allow the driv
4、er to manually select the current gear are called Manumatics. A manual-style transmission operated by computer is often called an automated transmission rather than an automatic.Contemporary automobile manual transmissions typically use four to six forward gears and one reverse gear, although automo
5、bile manual transmissions have been built with as few as two and as many as eight gears. Transmission for heavy trucks and other heavy equipment usually have at least 9 gears so the transmission can offer both a wide range of gears and close gear ratios to keep the engine running in the power band.
6、Some heavy vehicle transmissions have dozens of gears, but many are duplicates, introduced as an accident of combining gear sets, or introduced to simplify shifting. Some manuals are referred to by the number of forward gears they offer (e.g., 5-speed) as a way of distinguishing between automatic or
7、 other available manual transmissions. Similarly, a 5-speed automatic transmission is referred to as a 5-speed automaticThe earliest form of a manual transmission is thought to have been invented by LouisRen Panhard and Emile Levassor in the late 19th century. This type of transmission offered multi
8、ple gear ratios and, in most cases, reverse. The gears were typically engaged by sliding them on their shaftshence the term shifting gears, which required a lot of careful timing and throttle manipulation when shifting, so that the gears would be spinning at roughly the same speed when engaged; othe
9、rwise, the teeth would refuse to mesh. These transmissions are called sliding mesh transmissions and sometimes called a crash box. Most newer transmissions instead have all gears mesh at all times but allow some gears to rotate freely on their shafts; gears are engaged using sliding-collar dog clutc
10、hes; these are referred to as constant-mesh transmissions.In both types, a particular gear combination can only be engaged when the two parts to engage (either gears or dog clutches) are at the same speed. To shift to a higher gear, the transmission is put in neutral and the engine allowed to slow d
11、own until the transmission parts for the next gear are at a proper speed to engage. The vehicle also slows while in neutral and that slows other transmission parts, so the time in neutral depends on the grade, wind, and other such factors. To shift to a lower gear, the transmission is put in neutral
12、 and the throttle is used to speed up the engine and thus the relevant transmission parts, to match speeds for engaging the next lower gear. For both upshifts and downshifts, the clutch is released (engaged) while in neutral. Some drivers use the clutch only for starting from a stop, and shifts are
13、done without the clutch. Other drivers will depress (disengage) the clutch, shift to neutral, then engage the clutch momentarily to force transmission parts to match the engine speed, then depress the clutch again to shift to the next gear, a process called double clutching. Double clutching is easi
14、er to get smooth, as speeds that are close but not quite matched need to speed up or slow down only transmission parts, whereas with the clutch engaged to the engine, mismatched speeds are fighting the rotational inertia and power of the engine.Even though automobile and light truck transmissions ar
15、e now almost universally synchronised, transmissions for heavy trucks and machinery, motorcycles, and for dedicated racing are usually not. Non-synchronized transmission designs are used for several reasons. The friction material, such as brass, in synchronizers is more prone to wear and breakage th
16、an gears, which are forged steel, and the simplicity of the mechanism improves reliability and reduces cost. In addition, the process of shifting a synchromesh transmission is slower than that of shifting a non-synchromesh transmission. For racing of production-based transmissions, sometimes half th
17、e teeth (or dogs) on the synchros are removed to speed the shifting process, at the expense of greater wear. Shafts Like other transmissions, a manual transmission has several shafts with various gears and other components attached to them. Typically, a rear-wheel-drive transmission has three shafts
18、: an input shaft, a countershaft and an output shaft. The countershaft is sometimes called a layshaft.In a rear-wheel-drive transmission, the input and output shaft lie along the same line, and may in fact be combined into a single shaft within the transmission. This single shaft is called a mainsha
19、ft. The input and output ends of this combined shaft rotate independently, at different speeds, which is possible because one piece slides into a hollow bore in the other piece, where it is supported by a bearing. Sometimes the term mainshaft refers to just the input shaft or just the output shaft,
20、rather than the entire assembly.In some transmissions, its possible for the input and output components of the mainshaft to be locked together to create a 1:1 gear ratio, causing the power flow to bypass the countershaft. The mainshaft then behaves like a single, solid shaft, a situation referred to
21、 as direct drive.Even in transmissions that do not feature direct drive, its an advantage for the input and output to lie along the same line, because this reduces the amount of torsion that the transmission case has to bear. Most front-wheel-drive transmissions for transverse engine mounting are de
22、signed differently. For one thing, they have an integral final drive and differential. For another, they usually have only two shafts; input and countershaft, sometimes called input and output. The input shaft runs the whole length of the gearbox, and there is no separate input pinion. At the end of
23、 the second (counter/output) shaft is a pinion gear that mates with the ring gear on the differential. Front-wheel and rear-wheel-drive transmissions operate similarly. When the transmission is in neutral, and the clutch is disengaged, the input shaft, clutch disk and countershaft can continue to ro
24、tate under their own inertia. In this state, the engine, the input shaft and clutch, and the output shaft all rotate independently.Shift modeMain article: Gear stickA 5 speed gear lever In many modern passenger cars, gears are selected by manipulating a lever connected to the transmission via linkag
25、e or cables and mounted on the floor of the automobile. This is called a gear stick, shift stick, gearshift, gear lever, gear selector, or shifter. Moving the lever forward, backward, left, and right into specific positions selects particular gears. An aftermarket modification of this part is known
26、as the installation of a short shifter which can be combined with an aftermarket shift knob or Weighted Gear Knob. A sample layout of a four-speed transmission is shown below. N marks neutral, the position wherein no gears are engaged and the engine is decoupled from the vehicles drive wheels. In re
27、ality, the entire horizontal line is a neutral position, although the shifter is usually equipped with springs so that it will return to the N position if not moved to another gear. The R marks reverse, the gear position used for moving the vehicle rearward. This layout is called the shift pattern.
28、Because of the shift quadrants, the basic arrangement is often called an H-pattern.While the layout for gears one through four is nearly universal, the location of reverse is not. Depending on the particular transmission design, reverse may be located at the upper left extent of the shift pattern, a
29、t the lower left, at the lower right, or at the upper right. There is usually a mechanism that only allows selection of reverse from the neutral position, to reduce the likelihood that reverse will be inadvertently selected by the driver. This is the most common five-speed shift pattern:This layout
30、is reasonably intuitive because it starts at the upper left and works left to right, top to bottom, with reverse at the end of the sequence and toward the rear of the car.This is another five-speed shift pattern, which can be found in Saabs, BMWs, some Audis, Volvos, Volkswagens, Opels, Hyundais, mo
31、st Renaults, some diesel Fords, and more:Dog-leg first shift patterns are used on many race cars and on older road vehicles with three-speed transmissions: The name derives from the up-and-over path between first and second gears. Its use is common in race cars and sports cars, but is diminishing as
32、 six speed and sequential gearboxes are becoming more common. This is a typical shift pattern for a six-speed transmission: Though eight-speed transmissions do exist, six forward speeds is widely considered to be the maximum that can be contained within a variation of the H shift pattern. In such a
33、case, Reverse is placed outside of the H, with a canted shift path, to prevent the shift lever from intruding too far into the drivers space (in left-hand drive cars) when reverse is selected. This is the most common layout for a six-speed manual transmission. Most front-engined, rear-wheel drive ca
34、rs have a transmission that sits between the driver and the front passenger seat. Floor-mounted shifters are often connected directly to the transmission. Front-wheel drive and rear-engined cars often require a mechanical linkage to connect the shifter to the transmission.References1.Synchronizers;
35、graphic illustration of how they work. Retrieved 2007-07-18.2. a b U.S. Department of Energy vehicle fuel economy website3.An Overview of Current Automatic, Manual and Continuously Variable Transmission Efficiencies and Their Projected Future Improvements, Kluger and Long, SAE 1999-01-12594.An Inves
36、tigation into The Loss Mechanisms associated with a Pushing Metal V-Belt Continuously Variable Transmission, Sam Akehurst, 2001, Ph. D Thesis, University of Bath.5.Rick Steves Europe: Driving in Europe6.Why Dual Clutch Technology Will Be Big Business. D. Retrieved 2010-02-07.手动变速器 概述手动变速器通常设有一个司机操纵离
37、合器和一个可移动的齿轮选择器。大多数汽车手动变速器，让驾驶者选择任何前进齿轮比（“齿轮”在任何时间），但有些如，常用于摩托车和赛车某些类型的安装，只允许司机选择下一个更高或下一个较低的齿轮。这种传送方式有时也被称为顺序手动变速器。顺序传输，通常用于赛车，使他们迅速转变。 手动变速器的特点是传动比通过锁定到内部齿轮对传动输出轴的选择。相反，大多数自动变速器的特点行星齿轮由刹车带传动和控制/或离合器选择齿轮比。自动变速器，让驾驶者手动选择当前齿轮被称为Manumatics。手动式变速器由计算机操作通常被称为半自动变速器，而不是自动变速箱。 现代汽车手动变速器，通常使用4至6个前进档和一个倒档，虽然
38、汽车手动变速器，已建成以尽可能少的两个和多达8对齿轮。重型卡车和其他重型设备的传输通常有至少9对这样的齿轮传动，可以同时提供一个广泛和密切的齿轮传动比，以保持发动机的功率的正常运行。一些重型汽车变速器齿轮有几十个，但很多是重复的，作为一个齿轮组相结合，以简化或变速转向时发生意外。有些手册所提到的数目，如前进档，他们提供（例如，5速自动之间的一种可手动变速器或其他识别方式）。同样，一个5速自动变速器被称为一个“5速自动”。手动变速器最早的形式被认为是由圣路易斯的勒内潘哈德和埃米尔勒瓦索尔发明于19世纪。这种传送方式提供多种传动比，齿轮是典型的沿着他们的轴滑动，因此所谓“换档齿轮”，这需要时间和油
39、门的精心操纵，使齿轮将在大致相同的旋转速度时进行，否则，齿轮会拒绝啮合。这些传动被称为“滑动啮合”的传动，大多数较新的变速器，不是在任何时候都啮合，但允许一些齿轮齿轮轴自由转动;这被称为“常啮合”的传动。在这两种类型，一个特定的齿轮组合，在同一速度只能进行两部分运动。转移到一个更高的齿轮，传动放在空挡位置，并允许缓慢降速，直到下一个齿轮传动部件在适当的速度下进行啮合。由于空挡和其他传动部件，车辆减速。所以在空挡时间取决于技巧水平，操作，和其他此类因素。转移到低档的齿轮，传动放在空挡和油门是用来加速，从而使有关的传动部件，以配合参与下一个低档的齿轮速度。对于这两个加减档，离合器分离，有些司机于从
40、一开始只用空挡而停止离合器和离合器的变化是没有做。其他司机会分离（脱离）离合器，转向空挡，然后进行短暂的分离，迫使传动部件，发动机转速匹配，然后再压低离合器转移到下一个齿轮，这个过程被称为双离合。双离合是比较容易得到顺利换挡，因为速度是相当比较接近，但不匹配时需要加快或减慢传动部分，从离合器到发动机，不匹配的速度与转动惯量和发动机功率相冲突。尽管汽车和轻型卡车变速器现在几乎普遍同步，但是重型卡车和摩托车变速器，以及专用赛车通常不是。有几个原因使用非同步传输的设计。摩擦材料，如黄铜，在同步器中更容易磨损；齿轮比，简单提高可靠性和降低成本。此外，实现同步器传输过程是一个较缓慢移动，而非同步器变速箱
41、，对于赛车的生产为基础的传输，有时一半的啮合齿环都被去掉，以加换挡速度，但要更多的磨损费用。轴像其他变速器一样，手动变速器有齿轮和附加到轴的其他零件。通常情况下，后轮驱动传动有三个轴：输入轴，一个副轴和输出轴。该副轴有时被称为中间轴。在后轮驱动的变速器中，输入和输出轴沿同一路线，事实上在变速器中可合并为一个单轴传动。这种单轴称为主轴。输入和输出两端这种组合轴以不同的速度独立旋转，这是可能的，因为一件轴滑入另一个轴的轴心，它是由轴承支承。有时这个词是指主轴，包括输入轴输出轴。在某些变速器中，输入和输出的主轴组件可能被固定，共同创造一个1:1齿轮比，使功率传动到中间轴。该主轴然后像一个单一实心轴传
42、动，这种情况被称为直接驱动。甚至在不直接驱动的变速器中，输入轴和输出轴沿一条直线这是一种优势，因为这减少了变速器要承担的扭转量。大多数前轮驱动的横置发动机变速器装配设计不同。一方面，他们有一个很完整的驱动力。另一方面，他们通常只有两轴，输入和副轴，有时也被称为输入轴和输出轴。输入轴齿轮箱运行的整个长度中也没有独立的输入小齿轮。在输出轴中是一个小齿轮轴端齿轮与输入轴齿轮的配合。前轮和后轮驱动变速器的操作方式相似。当变速器是空挡时，是脱离离合器，输入轴，离合器盘和副轴旋转可以继续根据自己的惰性。在这种状态下，发动机，输入轴和离合器，输出轴都独立地自转。换挡方式主要文章：换挡杆一个5速变速杆在许多现
43、代轿车，选择齿轮操纵或通过安装在汽车地盘上电缆连接的换挡杆联动。这就是所谓的排档杆，换档杆，换档，换档杆，齿轮选择器。移动换挡杆向前，向后，左，右到具体位置选择特定齿轮。这部分是售后众所周知的一段，可与售后市场的换档把手或加权齿轮旋钮组合安装。一个四速传动样本布局如下。N标志着空挡位置，其中没有齿轮活动和发动机与汽车的驱动车轮没有关系。实际上，整个水平线是一个中立的位置，如果不移动到另一个挡位换档时后由回位弹簧使其返回到N的位置。相反的R标记，是倒档。这个布局被称为换挡模式。由于换挡象限，基本方式是通常被称为一个H -格局。虽然这个布局对齿轮1到4几乎是普遍的，但没有倒档的位置。根据特定的传动
44、设计，倒档也许位于换挡模式的左上部，在左下角，右下角，或在右上方。通常有一种装置，只允许倒档的选择从空挡选，减少的无意中挂错倒档的可能性。这是最共同的五速度转移模式：因为它开始在左上部并且传动由左到右，由上至下，与倒档在序列的结尾和向汽车的后方，这种布局是合理的。这是另一个五速度换挡模式，可以在Saabs， BMWs，某一Audis， Volvos， Volkswagens， Opels， Hyundais，多数Renaults，一些柴油论坛，或者其他地方找到：这种换挡模式首先使用在许多赛车和三速度传输的更旧的公路车辆：这个名字源于向上及以上第一和第二齿轮之间的道路，它常用语赛车和跑车，由于六
45、速连续变速器的频繁使用，这种换挡模式在逐渐减少。这是六速变速器的一个典型的换挡模式：虽然8速变速器的确存在，6个前进的速度被广泛认为是可以在一个的“H”的格局转变中的最大变化。在这种情况下，倒档放在“H”的外面，有斜移路径，以防止侵入驾驶员挂档时，倒档被选中。这是一个六速手动变速器最常见的布局。大多数前置后驱轿车，变速器安装在司机和前排乘客座位之间。地盘安装换挡杆通常是直接连接到变速器中。前轮驱动和后置发动机汽车往往需要一个机械连杆连接的变速器来传输。参考文献1.Synchronizers;graphicillustrationofhow they work. Retrieved 2007-0
46、7-18.2. a b U.S. Department of Energy vehicle fuel economy website3.An Overview of Current Automatic, Manual and Continuously Variable Transmission Efficiencies and Their Projected Future Improvements, Kluger and Long, SAE 1999-01-12594. An Investigation into The Loss Mechanisms associated with a Pushing Metal V-Belt Continuously Variable Transmission, Sam Akehurst, 2001, Ph. D Thesis, University of Bath.5.Rick Steves Europe: Driving in Europe6.Why Dual Clutch Technology Will Be Big Business. D. Retrieved 2010-02-07.
