The system comprises several basic components, such as the primary pulley assembly, secondary pulley assembly, metal belt, and hydraulic pump, etc.:
Specifically, the metal belt consists of multiple metal rings and metal segments. Both the primary and secondary pulley assemblies are composed of a movable sheave and a fixed sheave. The sheave on the side closer to the hydraulic cylinder can slide along the shaft, while the other side is fixed. Both the movable and fixed sheaves have a conical structure, and their conical surfaces form a V-groove to engage with the V-shaped metal drive belt. The power output from the engine is first transmitted to the CVT's primary pulley, then transferred to the secondary pulley via the V-shaped drive belt, and finally transmitted to the wheels through the reducer and differential to drive the vehicle.
The driver can adjust the axial movement of the movable sheave by controlling the hydraulic cylinder pressure of the primary and secondary pulley hydraulic pumps, thereby achieving stepless speed change. The function of the secondary hydraulic cylinder is to control the tension of the metal belt, ensuring efficient and reliable transmission of power from the engine. The primary hydraulic cylinder controls the axial movement of the primary conical sheave. As the metal belt moves along the V-groove in the primary pulley assembly, and since the length of the metal belt remains constant, the metal belt in the secondary pulley assembly changes its position along the V-groove in the opposite direction. The operating radii of the metal belt on the primary and secondary pulley assemblies change, achieving continuous variation of the gear ratio.
When the vehicle starts, the primary pulley's operating radius is small, allowing the transmission to achieve a larger gear ratio, thus ensuring the drive axle has sufficient torque for high acceleration. As vehicle speed increases, the primary pulley's operating radius gradually increases, and the secondary pulley's operating radius decreases accordingly. The CVT's gear ratio decreases, allowing the vehicle to travel at higher speeds.
