Clamping force adjustment system for a continuously variable transmission

Abstract

Continuously variable transmission (CVT) with a metal pushing V-belt (MPVB) is a type of transmission that is widely used for automotive application. In this type of CVT, engine torque is transferred to the vehicle’s wheels using the traction between MPVB and the CVT’s pulleys. Therefore, sufficient clamping force from the pulleys to MPVB is required. Conventionally, the clamping force is generated by extracting some of the engine power through an oil pump in a hydraulic actuation system. The oil pump converts the engine power into hydraulic pressure exerted on the CVT pulleys so that MPVB can be clamped accordingly. This process, nevertheless, causes inefficiency in the vehicle’s powertrain system since less power is transmitted to the wheels. To address this issue, this paper describes a design of clamping force adjustment system using screw-thread mechanism.