Transmission principle of metal belt type continuously variable transmission
The principle of shifting the continuously variable transmission is simple, but it is also very clever. The fixed and movable portions of the main and passive working wheels of the actuator form a V-shaped groove that engages with the metal conveyor. When the movable part of the main and passive working wheels moves axially, the radius of gyration of the conveyor belt is changed, thereby changing the transmission ratio. The axial movement of the movable wheel is continuously adjusted by the hydraulic control system according to the use requirements of the automobile, and the continuously variable transmission is realized.
The shifting part consists of a primary pulley (primary wheel), a V-shaped metal belt and a passive pulley (secondary wheel). Each pulley is made up of a half pulley with a bevel, one of which is fixed and the other half is controlled by a hydraulic servo cylinder. The axial relative displacement between the half wheels can be changed by the control mechanism; the distance between the two pulley shafts is fixed, and the circumference of the transmission belt is fixed, so the gear ratio is formed when the radius r1 of the driving wheel is small. When the radius (the distance between the half wheels is wider), when the radius r2 of the driven wheel is at a larger radius (the distance between the half wheels is narrower), the transmission of the power train is relatively large, which is equivalent to the low-speed operation of the car. On the contrary, it is equivalent to high-end exercise. Infinitely variable speed is achieved by controlling the continuous changes of r1 and r2. That is, by controlling the axial movement of the movable portion of the main and passive wheels, the radius of gyration of the belt is changed, thereby obtaining a continuous transmission ratio.