What is the main purpose of a transmission?

[LeMary]

Transmission is primarily used to alter the speed and torque from the engine. It can fix or change the gear ratio between the output shaft and input shaft in steps, hence also known as a gearbox. The transmission consists of two main parts: the gear transmission mechanism and the gear shifting mechanism. The main function of the gear transmission mechanism is to change the magnitude and direction of torque and speed, while the main function of the shifting mechanism is to control the transmission mechanism to achieve changes in the gear ratio, i.e., to shift gears for speed and torque variation. Automotive transmissions are divided into manual and automatic types. Manual transmissions mainly consist of gears and shafts, achieving speed and torque variation through different gear combinations. Automatic transmissions (AT), on the other hand, are composed of a torque converter, planetary gears, a hydraulic torque variation system, and a hydraulic control system, achieving speed and torque variation through hydraulic power transmission and gear combinations.