sun gear so that it can't move.
行星齿轮组的一个用法就是将内齿圈与来自发动机的输入轴 相连，将行星架与输出轴相连，并锁止太阳轮，使其无法运动。
In this scenario, when we turn the ring gear, the planets will \held stationary) causing the planet carrier to turn the output shaft in the same direction as the input shaft but at a slower speed causing gear reduction (similar to a car in first gear).
这种情况下，当转动内齿圈，行星齿轮将沿着被固定的太阳轮旋转，从而行星齿轮架带动输出轴以与输入轴相同方向转动，但速率较小，来实现减速，类似于普通变速器的一档。
If we unlock the sun gear and lock any two elements together, this will cause all three elements to turn at the same speed so that the output shaft will turn at the same rate of speed as the input shaft. This is like a car that is in third or high gear.
如果我们使得太阳轮自由转动，将行星架和内齿圈连接起来，这使得所有三个部件以同一转速旋转，则输出轴和输入轴的转速相同。这类似于汽车位于三档或者更高档位。
Another way that we can use a planetary gear set is by locking the planet carrier from moving, then applying power to the ring gear which will cause the sun gear to turn in the opposite direction giving us reverse gear.
还有一种方法是固定行星架，将内齿圈作为主动件，太阳轮作为从动件，此时，太阳轮转动方向与内齿圈相反，相当于倒档。
The illustration in Figure 9-1 shows how the simple system described above would look in an actual transmission. The input shaft is connected to the ring gear. The output shaft is connected to the planet carrier which is also connected to a \
图9-1（Figure 9 dash 1）给出实际自动变速器中上述系统的
形状。图中的输入轴与内齿圈相连，输出轴与行星架相连，行星架连接着离合器磨擦片。 The sun gear is connected to a drum which is also connected to the other half of the clutch pack. Surrounding the outside of the drum is a band that can be tightened around the drum when required to prevent the drum with the attached sun gear from turning.
太阳轮与制动鼓相连，制动鼓与离合器磨擦片的另一半面相连。制动带环绕制动鼓四周，当要求固定住与制动鼓相连的太阳轮时，制动带压紧制动鼓。
The clutch pack is used, in this instance, to lock the planet carrier with the sun gear forcing both to turn at the same speed. If both the clutch pack and the band were released, the system would be in neutral.
此时，离合器被用来将行星架和太阳轮固定在一起，使得两者以相同的转速旋转。如果离合器和制动带松离，系统处于空档状态。
Turning the input shaft would turn the planet gears against the sun gear, but since nothing is holding the sun gear, it will just spin free and have no effect on the output shaft.
转动输入轴，将使得行星轮绕着太阳轮旋转，但此时太阳轮没有被固定，它将自由旋转，对输出轴没有作用。
To place the unit in first gear, the band is applied to hold the sun gear from moving. To shift from first to high gear, the band is released and the clutch is applied causing the output shaft to turn at the same speed as the input shaft.
当制动带将太阳轮固定住，则此时变速器处以一档。制动带松开，离合器使得输出轴与输入
41
轴转速相同，此时自动变速器从一档切换到高档（直接档）。
Many more combinations are possible using two or more planetary sets connected in various ways to provide the different forward speeds and reverse that are found in modem automatic transmissions.
对于现代自动变速器，通过两个或更多的行星齿轮组以不同的方式连接从而提供更多的不同的前进和倒档档位。
9.2 Clutch pack
9.2 离合器片组
A clutch pack consists of alternating disks that fit inside a clutch drum. Half of the disks are steel and have splines that fit into groves on the inside of the drum. The other half have a friction material bonded to their surface and have splines on the inside edge that fit groves on the outer surface of the adjoining hub.
离合器片组由位于离合器鼓间的许多可替换的离合器磨擦片组成。这些磨擦片的一面是钢结构，上面有与离合器鼓凹槽配合的花键，另一面是粘结的磨擦材料，在内边缘上有花键，与连接的毂外表面的凹槽配合。
There is a piston inside the drum that is activated by oil pressure at the appropriate time to squeeze the clutch pack together so that the two components become locked and turn as one. 在离合器鼓中间有一个油压驱动的活塞，在恰当的时机活塞压紧离合器片组，使得两个部件被固定在一起。 9.3 One-Way Clutch 9.3 单向离合器
A one-way clutch (also known as a “sprag” clutch) is a device that will allow a component such as ring gear to turn freely in one direction but not in the other. This effect is just like that of a bicycle, where the pedals will turn the wheel when pedaling forward, but will spin free when pedaling backward. 单向离合器（也被称作楔式离合器）可以允许一个部件，比如：内齿圈向一个方向自由旋转，而不能向另一个方向旋转。这个作用类似于自行车，当向前踏动踏板，踏板带动车轮旋转，而向后踏动踏板，它将自由旋转。
A common place where a one-way clutch is used is in first gear when the shifter is in the drive position. When you begin to accelerate from a stop, the transmission starts out in first gear. But have you ever noticed what happens if you release the gas while it is still in first gear? The vehicle continues to coast as if you were in neutral.
当换档手柄处于D档时，单向离合器通常用于一档。当你从静止开始加速时，变速器从一档开始。当变速器还处于一档时，如果你松开油门，你注意到会发生什么？汽车继续滑行，就像你切入空档一样。
Now, shift into Low gear instead of Drive. When you let go of the gas in this case, you will feel the engine slow you down just like a standard shift car. The reason for this is that in Drive, a one-way clutch is used whereas in Low, a clutch pack or a band is used. 现在将换档手柄放在L档。此时，当你松开油门，你会感到汽车减速，和标准手动换档一样。这是因为当变速器处于D 档，变速器使用单向离合器，而当变速器处于L档，变速器使用离合器片或制动带。 9.4 Bands
42
9.4 制动带
A band is a steel strap with friction material bonded to the inside surface. One end of the band is anchored against the transmission case while the other end is connected to a servo. At the appropriate time hydraulic oil is sent to the servo under pressure to tighten the band around the drum to stop the drum from turning.
制动带是一条钢带，其中内表面粘结摩擦材料。制动带的一端固定在变速器壳体，另一端与液压伺服系统相连。适当的时机下，液压油压入伺服系统，从而压紧环绕在转鼓上的制动带，停止转鼓旋转。
9.5 液力变矩器 9.5 液力变矩器
On automatic transmissions, the torque converter takes the place of the clutch found on standard shift vehicles. It is there to allow the engine to continue running when the vehicle comes to a stop.
液力变矩器在自动变速器中的作用类似手动变速器系统中的离合器。它可以使得当汽车趋向停止时，发动机依然运转。The principle behind a torque converter is like taking a fan that is plugged into the wall and blowing air into another fan which is unplugged. If you grab the blade on the unplugged fan, you are able to hold it from turning but as soon as you let go, it will begin to speed up until it comes close to the speed of the powered fan. The difference with a torque converter is that instead of using air, it uses oil or transmission fluid, to be more precise. 液力变矩器工作原理类似将一个风扇固定在墙上，用它向另一个没有固定的风扇吹风。如果你抓住没有固定风扇的叶片，则风扇停止旋转。当你一旦松开，叶片就会加速旋转直至与固定的风扇转速接近。液力变矩器和它的区别就是液力变矩器不使用空气，而是使用油或变速器油，从而控制更加精确。
A torque converter is a large doughnut shaped device that is mounted between the engine and the transmission. It consists of three internal elements that work together to transmit power to the transmission. The three elements of the torque converter are the Pump, the Turbine, and the Stator.
液力变矩器是一个位于发动机和变速器之间的圆环形设备。它内部由三个部件组成，这三个部件一起工作，传递功率给变速器。这三个部件是泵轮，涡轮和导轮。
The pump is mounted directly to the converter housing which in turn is bolted directly to the engine’s crankshaft and turns at engine speed.
泵轮直接装在变矩器壳上，它与发动机曲轴直接螺栓连接，和发动机转速相同。
The turbine is inside the housing and is connected directly to the input shaft of the transmission providing power to move the vehicle.
涡轮位于变速器壳体内，与变速器输入轴直接相连，给汽车提供行进的动力。
The stator is mounted to a one-way clutch so that it can spin freely in one direction but not in the other. Each of the three elements has fins mounted in them to precisely direct the flow of oil through the converter.
导轮通过单向离合器安装，这样它就可以沿着一个方向自由旋转，而不能反方向自由旋转。
43
这三个部件都有叶片，精确引导变速器油在变矩器内的流动。
With the engine running, transmission fluid is pulled into the pump section and is pushed outward by centrifugal force until it reaches the turbine section which starts it turning.
随着发动机的转动，变速器油被推入泵轮区域，又被离心力甩至外缘，直到涡轮区域，并使得涡轮转动。
The fluid continues in a circular motion back towards the center of the turbine where it enters the stator. If the turbine is moving considerably slower than the pump, the fluid will make contact with the front of the stator fins which push the stator into the one way clutch and prevent it from turning.
油液继续圆周方向运动，流向涡轮中心，从那里进入导轮。如果涡轮比泵轮转动得慢得多，油液就接触到了导轮叶片的前面，推动导轮使单向离合器起作用，阻止导轮转动。
With the stator stopped, the fluid is directed by the stator fins to re-enter the pump at a \angle providing a torque increase. As the speed of the turbine catches up with the pump, the fluid starts hitting the stator blades on the back-side causing the stator to turn in the same direction as the pump and turbine. As the speed increases, all three elements begin to turn at approximately the same speed.
由于导轮静止，油液被导轮的叶片引领，以一个使得转矩增加的角度重新进入泵轮。随着涡轮的转速赶上泵轮，油液开始冲击导轮叶片的背面，使得导轮沿着与泵轮和涡轮相同的方向旋转。随着速度的升高，这三个部件以近似相同的转速旋转。
Since the '80s, in order to improve fuel economy, torque converters have been equipped with a lockup clutch which locks the turbine to the pump as the vehicle speed reaches approximately 45~50 mph. This lockup is controlled by computer and usually won't engage unless the transmission is in 3rd or 4th gear.
80年代以来，为了提高燃油经济性，液力变矩器装配了一个锁止离合器。当车速达到大约45-50英里/小时，锁止离合器将涡轮和泵轮锁止在一起。锁止离合器由计算机控制，如果变速器还没有升至3档或4档，锁止离合器一般不会接合。
9.6 Hydraulic System
9.6 液压系统
The Hydraulic system is a complex maze of passages and tubes that sends transmission fluid under pressure to all parts of the transmission and torque converter. Transmission fluid serves a number of purposes including: shift control, general lubrication and transmission cooling. 变速器液压系统是一个复杂的管路和管道迷宫。它将压力下的变速器油送到变速器和液力变矩器的所有部件。变速器油有以下作用：换档控制，总体润滑和变速器冷却。
Unlike the engine, which uses oil primarily for lubrication, every aspect of a transmission’s functions is dependant on a constant supply of fluid under pressure.
与发动机首先使用机油来润滑不同，变速器的每个功能都需要恒定的油量供给。
In order to keep the transmission at normal operating temperature, a portion of the fluid is sent through one of two steel tubes to a special chamber that is submerged in anti-freeze in the radiator. Fluid passing through this chamber is cooled and then returned to the transmission through the other steel tube.
为了使变速器运行在正常的温度下，一部分变速器油通过钢管送到散热器中一个浸泡在防冻
44
相关推荐：
loading