On the Advanced Efficiency Analysis for Half Toroidal CVT - The Efficiency Analysis Considering Deformation of CVT Components

The purpose of this research work is to develop more accurate calculating method of the efficiency of a half toroidal CVT. Previous analysis does not consider the bulk deformation of the CVT components. However, the bulk deformation of the CVT components is not negligible to predict the efficiency of the unit. For example, the half-contact angle between the power roller and disks is changed due to the deformation of these components at the high contact load. Therefore, it is important to establish more accurate calculating method of efficiency considering the bulk deformation for the high performance CVT unit, that is compact, highly efficient, and provides high-torque capability.

This paper describes the analytical method to calculate the efficiency of the CVT taking the deformation into consideration. Firstly, the analysis of the efficiency on the traction surface considering deformation of the trunnion is shown. Secondly, the loss of power roller considering the deformation of pivot shaft is calculated. Finally, the total efficiency of the CVT variator (CVT unit) is shown using the new method.