Study of the Control Mechanism of a Half-Toroidal CVT during Load Transmission

In November 1999, the first vehicle with a traction drive CVT (continuously variable transmission) was manufactured and introduced to the market. The speed ratio changing mechanism of the half-toroidal CVT was theoretically analyzed by applying two equations of motion. However, neither analysis covers the effects of clearance and elastic deformation of the variator. Therefore, neither analysis can show correctly the behavior of the half-toroidal CVT during load transmission.In this paper, we present a new analytical model for determining the elastic deformation and clearance of the half-toroidal CVT. We have implemented systematically our analytical model using MATLAB and Simulink. As a result, we can determine the behavior of the half-toroidal CVT during load transmission.