Realize continuous change of speed ratio

- Apr 10, 2018-

The CVT system mainly includes basic components such as driving wheels, driven wheels, metal belts and hydraulic pumps. The metal strip consists of two bundles of metal rings and several hundred metal sheets. Both the driving wheel set and the driven wheel set consist of a movable plate and a fixed plate. The pulley on the side near the cylinder can be slid on the shaft and fixed on the other side. Both the movable plate and the fixed plate have a tapered surface structure, and their tapered surfaces form a V-shaped groove to engage with the V-shaped metal belt.

The power output from the output shaft of the engine is first transmitted to the drive wheels of the CVT, then transmitted to the driven wheels through the V-shaped belt, and finally transmitted to the wheels through the speed reducer and the differential to drive the car. When working, the movable disk of the driving wheel and the driven wheel is moved axially to change the working radius of the driving wheel and the driven wheel taper surface engaging with the V-shaped driving belt, thereby changing the transmission ratio. The amount of axial movement of the movable disk is achieved by the driver adjusting the pressures of the hydraulic cylinders of the driven wheel and the driven wheel through the control system as required. Because the working radius of the driving wheel and the driven wheel can be adjusted continuously, stepless speed change can be achieved.

When the car starts, the working radius of the driving wheel is smaller, and the transmission can obtain a larger transmission ratio, thereby ensuring that the driving axle can have sufficient torque to ensure that the vehicle has a higher acceleration. With the increase of the vehicle speed, the working radius of the driven wheel is gradually reduced, the working radius of the driving wheel is correspondingly increased, and the transmission ratio of the CVT is decreased, so that the automobile can run at a higher speed.

In the hydraulic system of the metal belt type continuously variable transmission, the role of the slave cylinder is to control the tension of the metal belt to ensure efficient and reliable transmission of power from the engine. The active cylinder controls the position of the active cone wheel to move in the axial direction, and the metal band of the driving wheel group moves along the V-shaped groove. Because the length of the metal belt is constant, the metal belt on the driven wheel group changes in the opposite direction along the V-shaped groove. The slewing radius of the metal belt on the driving wheel group and the driven wheel group changes to achieve a continuous change in the speed ratio.