车辆工程专业毕业论文外文翻译2(推荐).doc

TRANSMISSION Of all transmission technologies, the manual gearbox is the most efficient; around 96 per cent of the energy that is put in comes out of the other end. But not everyone can drive one or wants to. Because you have to dip the clutch pedal, it is less comfortable to drive in heavy traffic. It makes the driver tired and the torque interruptions’ head-nod effect on passengers can be wearing. The drivers clutch control and corresponding torque interruptions are also the manuals weak point. When accelerating up through the gearbox, each up-shift requires the driver to cut the torque momentarily by lifting the gas pedal and dipping the clutch. It may just take a second to complete the operation, but during this time the vehicle is losing speed and acceleration. At the opposite end of the spectrum is the traditional automatic. The modern transmission is by far, the most complicated mechanical component in today’s automobile. It is a type of transmission that shifts itself .A fluid coupling or torque converter is used instead of a manually operated clutch to connect the transmission to the engine. There are two basic types of automatic transmissions based on whether the vehicle is rear wheel drive . On a rear wheel drive car , the transmission is usually mounted to the back of the engine and is located under the hump in the center of the floorboard alongside the gas pedal position . A drive shaft connects the rear of the transmission to the final drive which is located in the rear axle and is used to send power to the rear wheel. Power flow on this system is simple and straight forward going from the engine, through the torque converter , then through the transmission and driver shaft until it reaches the final driver where it is split and sent to the two rear wheel . On a front wheel drive car, the transmission is usually combined .With the final drive to from what is called a transaxle. The engine on a front wheel driver car is usually mounted sidewa