A device of changes in machine tool, auto, tractor etc. machine running speed or traction, composed of many different diameter size of the gear. Usually installs in the engine between main drive shaft and driven shaft. Transmission is a gear drive device that can be fixed or tranche change the output shaft and input shaft transmission ratio, also known as the gearbox.
According to the transmission ratio change way, transmission can be divided into a step-type, stepless type and comprehensive type.
1, step-type transmission, it is one of the most widely used. It adopts gear drive, has a number of optional fixed transmission ratio. According to the different gear train type used, there are two kinds of axis fixed transmission and axis rotary transmission.
2, stepless type transmission, it is to point to any transmission ratio can be gained continuous variable speed range of variable speed system. Through the stepless variable speed can get the best match between the transmission and engine working conditions. Common stepless transmission has hydraulic type, mechanical and electric type, etc.
3, comprehensive type transmission, it is to point to by step-type transmission and stepless type transmission combined the transmission, the transmission ratio can be several discontinuities between the maximum and the minimum range of stepless change.
According to the operation manner, transmission can be divided into mandatory operation manner, automatic operation manner and semi-automatic operation manner.
1, mandatory operation manner transmission: rely on the driver directly operation the shift lever to change gear.
2, automatic operation manner transmission: the choice of transmission ratio and the gear shift are automatic. Drivers need to operate the speed up accelerator pedal, transmission can according to engine load signal and speed signal to control executive component, implement gear change.
3, semiautomatic operation manner transmission: can be divided into two kinds, one kind is part of the automatic gear shift, part of the gear shift compulsory; Another kind is with a button the selected gear in advance, while on the clutch pedal or loosen the accelerator pedal, shift by enforcement agencies themselves.
Transmission is one of the main components in the automobile drive train. Because the transmission in a wide range, can change the size of the motor speed and the size of the car on the driving wheel torque; as well as can achieve reverse driving and implementation gap. Auto transmission generally is composed of box body and box body after before, it is by changing the gear ratio, change torque of the engine crankshaft, adapt to drive the starting, acceleration, and overcome various under different driving conditions, such as road block on the drive wheel traction and speed of different needs.