神野牌轻型载货汽车变速器设计-中间轴式五档手动【含6张cad图纸+文档全套资料】

喜欢就充值下载吧。。资源目录里展示的文件全都有，，请放心下载，，有疑问咨询QQ:414951605或者1304139763 ======================== 喜欢就充值下载吧。。资源目录里展示的文件全都有，，请放心下载，，有疑问咨询QQ:414951605或者1304139763 ======================== Manual transmission 1.Introduction The purpose of the transmission in an automobile is to transfer the power created by the engine to the wheels via a drive shaft or half-axles. Differing gears in the transmission allow for different levels of torque to be applied to the wheels depending on the speed at which the vehicle is traveling. In order to change the level of torque the gears in the transmission need to be shifted either manually or automatically. In the beginning all transmissions were manual.French inventors Louis-Rene Panhard and Emile Levassor are credited with the development of the first modern manual transmission. They demonstrated their three-speed transmission in 1894 and the basic design is still the starting point for most contemporary manual transmissions.Panhard and Levassor used a chain drive on their original transmission. In 1898 auto maker Louis Renault used their basic design, but substituted a drive shaft for the drive chain and added a differential axle for the rear wheels to improve performance of the manual transmission.By the beginning of the 20th century most cars manufactured in the United States featured a non-synchronized manual transmission based on the Panhard/Levassor/Renault design. The next major innovation occurred in 1928 when Cadillac introduced the synchronized manual transmission, which significantly reduced gear grinding and made shifting smoother and easier.Manual transmissions were the standard on most vehicle for the first half of the 20th century, but automatic transmissions were being developed as far back as 1904. General Motors introduced the clutchless automatic transmission under the moniker, Hydra-Matic, in 1938, but the first true fully automatic transmission didn't appear until 1948 with the Buick Dynaflow transmission. 2.Background Americans tend to prefer automatic transmission in their vehicles while Western Europe is--and is expected to remain--the largest market for manual transmissions through 2014. Eastern Europe and Asia are also large markets for manual transmission although Japan appears to be embracing more automatic transmissions. In the United States, more manual transmissions are found in the Northern states than in the Southern states. It is surmised that manual transmissions give better control on icy roads and are thus more useful in the North where the winters are more harsh. Sports cars are often equipped with manual transmissions because they offer more direct driver involvement and better performance, though this is changing as many automakers move to faster dual-clutch transmissions, which are generally shifted with paddles located behind the steering wheel. For example, the 991 Porsche 911 GT3 uses Porsche's PDK. Off-road vehicles and trucks often feature manual transmissions because they allow direct gear selection and are often more rugged than their automatic counterparts. Conversely, manual transmissions are no longer popular in many classes of cars sold in North America, Australia and some parts of Asia, although they remain dominant in Europe, Asia, Africa and Latin America. Nearly all cars are available with an automatic transmission option, and family cars and large trucks sold in the US are predominantly fitted with automatics, however in some cases if a buyer wishes he/she can have the car fitted with a manual transmission at the factory. In Europe most cars are sold with manual transmissions. Most luxury cars are only available with an automatic transmission. In most cases where both transmissions are available for a given car, automatics are an at cost option, but in some cases the reverse is true. Some cars, such as rental cars and taxis, are nearly universally equipped with automatic transmissions in countries such as the US, but the opposite is true in Europe. As of 2008, 75.2% of vehicles made in Western Europe were equipped with manual transmission, versus 16.1% with automatic and 8.7% with other. Some trucks have transmissions that look and behave like ordinary car transmissions—these transmissions are used on lighter trucks, typically have up to 6 gears, and usually have synchromesh. 3. Composition for Manual Transmission. Manual transmissions often feature a driver-operated clutch and a movable gear stick. 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 of 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. In a manual transmission, the flywheel is attached to the engine's crankshaft and spins along with it. The clutch disk is in between the pressure plate and the flywheel, and is held against the flywheel under pressure from the pressure plate. When the engine is running and the clutch is engaged (i.e., clutch pedal up), the flywheel spins the clutch plate and hence the transmission. As the clutch pedal is depressed, the throw out bearing is activated, which causes the pressure plate to stop applying pressure to the clutch disk. This makes the clutch plate stop receiving power from the engine, so that the gear can be shifted without damaging the transmission. When the clutch pedal is released, the throw out bearing is deactivated, and the clutch disk is again held against the flywheel, allowing it to start receiving power from the engine.Manual transmissions are characterized by gear ratios that are selectable by locking selected gear pairs to the output shaft inside the transmission. Contemporary automobile manual transmissions typically use four to six forward gear ratios and one reverse gear, although consumer automobile manual transmissions have been built with as few as two and as many as seven gears. Transmissions for heavy trucks and other heavy equipment usually have 8 to 25 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. Operating aforementioned transmissions often use the same pattern of shifter movement with a single or multiple switches to engage the next sequence of gear selection. 3.1 Transmission shaft 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: an input shaft, a countershaft and an output shaft. The countershaft is sometimes called a layshaft.In many transmissions the input and output components of the mainshaft can 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 as direct drive.Even in transmissions that do not feature direct drive, it's 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.Under one possible design, the transmission's input shaft has just one pinion gear, which drives the countershaft. Along the countershaft are mounted gears of various sizes, which rotate when the input shaft rotates. These gears correspond to the forward speeds and reverse. Each of the forward gears on the countershaft is permanently meshed with a corresponding gear on the output shaft. However, these driven gears are not rigidly attached to the output shaft: although the shaft runs through them, they spin independently of it, which is made possible by bearings in their hubs. 3.2 Synchromesh Most modern manual-transmission vehicles are fitted with a synchronized gear box. Transmission gears are always in mesh and rotating, but gears on one shaft can freely rotate or be locked to the shaft. The synchronizer has to overcome the momentum of the entire input shaft and clutch disk when it is changing shaft rpm to match the new gear ratio. It can be abused by exposure to the momentum and power of the engine, which is what happens when attempts are made to select a gear without fully disengaging the clutch. This causes extra wear on the rings and sleeves, reducing their service life. When an experimenting driver tries to "match the revs" on a synchronized transmission and force it into gear without using the clutch, the synchronizer will make up for any discrepancy in RPM. The success in engaging the gear without clutching can deceive the driver into thinking that the RPM of the layshaft and transmission were actually exactly matched. Nevertheless, approximate rev. matching with clutching can decrease the difference in rotational speed between the layshaft and transmission gear shaft, therefore decreasing synchro wear. In a synchromesh gearbox, to correctly match the speed of the gear to that of the shaft as the gear is engaged the collar initially applies a force to a cone-shaped brass clutch attached to the gear, which brings the speeds to match prior to the collar locking into place. The collar is prevented from bridging the locking rings when the speeds are mismatched by synchro rings (also called blocker rings or baulk rings, the latter being spelled balk in the U.S.). The synchro ring rotates slightly due to the frictional torque from the cone clutch. In this position, the dog clutch is prevented from engaging. The brass clutch ring gradually causes parts to spin at the same speed. When they do spin the same speed, there is no more torque from the cone clutch and the dog clutch is allowed to fall into engagement. In a modern gearbox, the action of all of these components is so smooth and fast it is hardly noticed. 3.3 Reverse Reverse gear is usually not synchromesh, as there is only one reverse gear in the normal automotive transmission and changing gears into reverse while moving is not required—and often highly undesirable, particularly at high forward speed. 3.4 Clutch Among many different types of clutches, a dog clutch provides non-slip coupling of two rotating members. It is not at all suited to intentional slipping, in contrast with the foot-operated friction clutch of a manual-transmission car. The gear selector does not engage or disengage the actual gear teeth which are permanently meshed. Rather, the action of the gear selector is to lock one of the freely spinning gears to the shaft that runs through its hub. The shaft then spins together with that gear. The output shaft's speed relative to the countershaft is determined by the ratio of the two gears: the one permanently attached to the countershaft, and that gear's mate which is now locked to the output shaft. Locking the output shaft with a gear is achieved by means of a dog clutch selector. The dog clutch is a sliding selector mechanism which is splined to the output shaft, meaning that its hub has teeth that fit into slots (splines) on the shaft, forcing that shaft to rotate with it. However, the splines allow the selector to move back and forth on the shaft, which happens when it is pushed by a selector fork that is linked to the gear lever. The fork does not rotate, so it is attached to a collar bearing on the selector. The selector is typically symmetric: it slides between two gears and has a synchromesh and teeth on each side in order to lock either gear to the shaft. 4.Fuel Economy The manual transmission couples the engine to the transmission with a rigid clutch instead of the torque converter on an automatic transmission or the v-belt of a continuously variable transmission, which slip by nature. Manual transmissions also lack the parasitic power consumption of the automatic transmission's hydraulic pump. Because of this, manual transmissions generally offer better fuel economy than automatic or continuously variable transmissions; however the disparity has been somewhat offset with the introduction of locking torque converters on automatic transmissions. Increased fuel economy with a properly operated manual transmission vehicle versus an equivalent automatic transmission vehicle can range from 5% to about 15% depending on driving conditions and style of driving. The lack of control over downshifting under load in an automatic transmission, coupled with a typical vehicle engine's greater efficiency under higher load, can enable additional fuel gains from a manual transmission by allowing the operator to keep the engine performing under a more efficient load/RPM combination. This is especially true as between manual and automatic versions of older models, as more recent advances including variable valve timing reduce the efficiency disadvantages of automatic transmissions by allowing better performance over a broader RPM range. In recognition of this, many current models (2010 and on) come with manual modes, or overrides on automatic models, although the degree of control varies greatly by the manufacturer. Also, manual transmissions do not require active cooling and because they are, mechanically, much simpler than automatic transmissions, they generally weigh less than comparable automatics, which can improve economy in stop-and-go traffic.[16] However this gap in economy is being rapidly closed, and many mid to higher end model automatic cars now get better economy than their standard spec counterparts[citation needed]. This is in part due to the increasing impact of computers co-ordinating multiple systems, particularly in hybrid models in which the engine and drive motors must be managed. 手动变速器 1.说明 汽车传动的目的是通过驱动轴或半轴将发动机驱动车轮的动力传递给车轮。在变速器中不同的齿轮允许不同程度的扭矩被施加到车轮上，这取决于车辆行驶的速度。为了改变变速器中的齿轮的转矩的水平，需要手动或自动移动。在开始时，所有的传输都是手动的。法国发明家路易斯雷内潘哈德和埃米尔勒瓦索被认为是第一个促进现代手动变速器的发展的人。他们在1894年展示了他们的三挡变速器，其基本的设计仍然是现代的手动变速器的起点。潘哈德和勒瓦索在原来传输的基础上改用链传动。1898年，汽车制造商路易斯雷诺使用他们的基本设计，但是使用了驱动轴取代了驱动链，并在后桥增加了一个差速器，以提高手动变速器性能。在第二十世纪初美国制造的大多数汽车采用了美国特色的非同步手动变速器都是基于潘哈德/勒瓦索/雷诺设计。下一个重大创新发生在1928年，当凯迪拉克推出同步手动变速器，这大大减少齿轮磨削，使换档更顺畅，更容易。在二十世纪上半年手动变速器的标准被大多数车辆采用，但自动变速器的开发可追溯到1904年。在1938年，通用汽车为生产的离合器自动变速器取名为Hydra-Matic，但第一个真正的全自动变速器的出现直到1948年的别克流体动力传输的出现。 2.背景 2014年调查显示，美国人更倾向于在他们的车上安装自动变速器，而西欧预计保持最大的手动变速器市场。东欧和亚洲也有大量的手动变速器市场，日本似乎拥有更多的自动变速器。在美国，手动变速器在北方各州比在南部各州更广为使用。据推测，手动变速器可以更好地控制在结冰的路面上的行驶，从而更有效的适应更恶劣的北方冬天。 跑车往往配备手动变速箱，因为他们提供更多的直接驱动的参与和更好的性能，尽管这是许多汽车制造商将更快的双离合器变速箱的变化，它通常是位 于方向盘桨移。例如，991保时捷911 GT3使用保时捷的PDK。越野车和卡车经常采用手动变速器，因为它们允许直接齿轮的选择，而且往往比他们的自动变速器更坚固耐用。 相反，在北美 国、澳大利亚以及亚洲的一些地区，手动变速器不再流行，虽然它们在欧洲、亚洲、非洲和拉丁美洲都是占主导地位的美国。几乎所有的汽车都可以与自动变速器的 选择，家庭轿车和大卡车在美国销售的主要配备自动化，但是在某些情况下，如果买方希望他/她能把车装在工厂的手动变速器。在欧洲，大多数汽车都是用手动变 速器出售的。大多数豪华车只能用一种自动变速器。在大多数情况下，传输，可用于一个给定的汽车，自动变速器是一个在成本的选择，但在某些情况下是正确的。 一些汽车，如出租汽车和出租车，几乎全世界都配备了自动变速器，如美国，但相反的是真实的，在欧洲，2008，75.2%的车辆在西欧，配备手动变速器， 与16.1%与自动和其他8.7%。一些卡车变速器的外观和行为像普通汽车变速器这些传输用于轻卡车，通常有6个齿轮，通常有同步。 3.变速器组成. 手动变速器通常有一个驱动操纵离合器和一个可移动的拨叉。大多数汽车的手动变速器允许司机在任何时候选择任何前进档位，但有些，如一般安装在摩托车和某些类型的赛车，只允许司机选择下一个或下一个较低的档位。这种类型的传输有时被称为顺序手动变速器。在一个手动变速器，飞轮是连接到发动机的曲轴和旋转一起。离合器盘在压力板与飞轮之间，并在压力下与飞轮保持在一起。当发动机运转时，离合器接合，飞轮转动离合器盘。由于离合器踏板是凹陷的，这会导致压力板停止向离合器盘施加压力。这使得离合器停止接收发动机的功率，使变速器可以换挡，而不损坏传输。当离合器踏板被释放时，分离轴承被停用，离合器盘再次被与飞轮接合，允许它开始从发动机接收功率。手动变速器的特点是通过锁定选定的齿轮副的传动比，从而决定传输的输出轴的齿轮比。 现代汽车的手动变速器通常采用（4+1）档，或者（6+1）档。虽然消费者的汽车手动变速器已经建立了七个档位。而且重型卡车和其他重型设备的变速器通常有8至25个档位，因此变速器可以同时提供一个较大范围的齿轮比，以保持发动机在最佳功率运行。操作上述变速器经常使用相同的模式。即选用一个或者多个操纵杆来进行档位的选择。 3.1 变速器轴 与其它变速器一样，手动变速器轴上包含不同的齿轮和其它连接部件。通常情况下，后轮驱动的变速器有三个轴：输入轴、中间轴和输出轴。副轴有时被称为中间轴。许多变速器的输入和输出的主轴组件可以被锁在一起，创建一个1:1的传动比，使功率流绕过副轴。主轴然后像一个单一的实心轴：这种情况称为直接驱动。直接驱动时输入和输出沿一条直线是一个很大的优势，因为这降低了扭矩，变速箱承受量。一个可能的设计，变速器的输入轴只有一个小齿轮，从而带动副轴。沿中间轴安装不同尺寸的齿轮，输入轴转动时。这些齿轮对应的正向速度和反向。每一个前进档中间轴上永久啮合输出轴上的相应齿轮。然而这些从动齿轮不刚性连接到输出轴：虽然轴运行通过他们，他们独立地旋转，这时由轴承在高速旋转。 3.2 变速器同步器 大多数现代的手动变速器都配有一个同步齿轮箱。变速器齿轮总是在啮合和旋转，但在一个轴上的齿轮可以自由旋转或被锁定到轴上。同步器克服了整个输入轴和离合器盘在改变轴的转速来匹配新的齿轮比。它可以通过暴露于发动机的动力选择一个齿轮来换挡，但没有完全分离离合器。这会导致环和套筒额外的磨损，减少他们的使用寿命。当司机试图尝试换挡，匹配的转速在同步传输和力成齿轮不使用离合器，同步将弥补换挡时转速的差异。不过近似配合，能降低中间轴和传动齿轮轴之间的转速差，因此降低同步磨损。 在一个同步器变速箱，正确匹配的齿轮转速，轴的齿轮啮合齿圈最初施加力到锥形黄铜离合器连接到齿轮，它匹配的齿圈锁定到之前带来的速度。衣领是防止连接锁定环时速度不匹配同步环。同步环轻微旋转，由于摩擦扭矩从锥形离合器到这个位置，离合器被阻止接合。黄铜离合器环逐渐使零件以相同的速度旋转。当它们旋转相同的速度，有没有更多的扭矩从锥形离合器和离合器被允许进入接触。在现代的齿轮箱，所有这些组件的作用是如此的平稳和快速，几乎没有注意到。 3.3 倒档 倒档齿轮通常是不同步的，因为普通的汽车变速器只有一个倒档，并且汽车正常行驶时不需要经常换到倒档，尤其是在高速行驶时。 3.4 离合器 在众多不同类型的离合器中，齿式离合器是提供非滑动耦合的双旋转的成员。它不限滑的，相反，干式摩擦离合器的手动变速器是限滑的。 同步器不接合或脱离永久啮合齿轮齿。同步器的作用是把一个自由旋转的齿轮锁定在轴上，通过它的中心，然后轴与齿轮一起旋转。输出轴的速度相对于副轴是由两齿轮的比值决定：一个永久连接到中间轴，且相啮合的齿轮现在锁定到输出轴。锁定输出轴与齿轮是通过一个离合器实现。离合器的机理是通过花键与输出轴实现，这意味着它的枢纽已融入槽齿（花键）在轴上，通过轴转动它。然而，花键允许花键毂在轴上来回移动，当它被一个与齿轮杆相连的拨叉推的时候，拨叉不旋转，所以它是连接到一个衣领轴承上的选择器。选择器器通常是对称的：它位于两档齿轮之间并有一个同步器把每侧齿轮锁到齿轮轴。 4.燃油经济性 手动变速器与离合器刚性连接，而不是像自动变速器、无级变速器的带液力变矩器传输引擎。手动变速器也缺乏自动变速器的液压泵的保存功率消耗功能。因此，手动变速器一般提供比自动或无级变速器更好的燃油经济性；然而，差距已经有所抵消，引进的自动变速器锁定扭矩转换器。增加燃油经济性与适当的操纵技巧，手动变速器汽车等效自动变速器的车辆，根据驾驶条件和驾驶风格可以在5%到15%的范围。在低档载荷下自动变速器控制的不足，再加上一个典型的汽车发动机的效率更高的负载，可以使手动变速器从额外的收益燃料允许经营者保持引擎执行U在一个更有效的负荷/转速组合。这是特别真实的手动和自动版本的旧机型，随着越来越多的最新进展，包括可变气门正时减少自动变速器的效率的缺点，允许更好的性能在更广泛的转速范围。认识到这一点，许多现有的模型（2010）来自手动模式、自动模式或重写，虽然控制程度差别很大。另外，手动变速器不需要主动冷却，因为他们是机械，比自动变速器简单得多，一般体重小于可比的自动化，从而提高经济在走走停停的交通。但是这种经济差距正在迅速关闭，很多中高端的模型自动车现在得到比标准规格的同行更好的经济。这部分是由于计算机协调多个系统的影响越来越大，特别是在混合动力车型的发动机和驱动电机必须管理。