The influence of lubricating oil on the performance of a metal V‐belt‐type continuously variable transmission

Abstract

AbstractThe influence of lubricating oil on the torque capacity and the efficiency of a continuously variable transmission (CVT) of metal V‐belt type were experimentally investigated using a commercial CVT unit with a belt assembly and pulley. In order to analyse the friction characteristics of each of the contacting parts in the CVT, a block‐on‐disc type friction testing machine was used. The maximum torque capacity between the belt and pulley in the actual CVT correlated with the friction coefficient under high contact pressure (200 MPa) and relatively high sliding velocity (0.1 m/s) on the friction testing machine. The transmission efficiency decreased as the load decreased. The maximum difference in the efficiency between all the commercial automotive transmission and CVT fluids tested reached 6%. It was found that the requirements for the efficiency of transmission at a lower load were in contradiction with the maximum torque capacity.