The core part of the continuously variable transmission in a car is the continuously variable transmission device. The continuously variable transmission device is composed of two pulleys and a steel belt. The steel belt is sleeved on the two pulleys. The pulley is composed of two figure-eight wheel walls. The groove in the middle of the two wheel walls forms a V shape. One of the wheel walls is controlled by a hydraulic control mechanism. During operation, the power output by the engine output shaft is first transmitted to the driving wheel of the continuously variable transmission, then transmitted to the driven wheel through the V-shaped transmission steel belt, and finally transmitted to the wheels through the reducer and differential to drive the car. During operation, the movable disc of the driving wheel and the driven wheel moves axially to change the meshing working radius between the driving wheel, the conical surface of the driven wheel and the V-shaped transmission belt, thereby achieving the purpose of changing the transmission ratio. The two pulleys can be adjusted in opposite directions, that is, when the groove of one pulley gradually becomes wider, the groove of the other pulley will gradually narrow.
Since the working radius of the driving wheel and the driven wheel can be continuously adjusted, the stepless speed change function is achieved