Torque transmission

When you start driving the driving wheels requires a considerable torque, while the engine develops at low revs a little time. In this case, you turn 1st gear, and the gear ratio due to its torque increases and the rotation of the wheels relative to the engine speed slows down.

When driving on the highway in the 5th gear reverse happens. Its gear ratio such that the engine speed when the torque transmission to the driving wheels is increased. Thus, with almost constant engine speed reaches the desired rotational speed of the wheels.

However, the kinematic connection between the engine and transmission may be interrupted - for example, when you start up the engine, standing at a traffic light with the engine running or want to shift gears. On vehicles with manual gearbox clutch performs this task. Thanks to him, it is also possible a smooth start of the movement, as it aligns the speed of the crankshaft and the drive shaft gearbox. In the automatic transmission performs the function of the clutch torque converter. The main advantages of an automatic gearbox as follows: the engine does not stall, there is no need for a gear change, which facilitates control of the vehicle.