Transmission ratio calibration for electro-mechanically actuated continuously variable transmission

Abstract

Continuously variable transmission (CVT) with a metal pushing V-belt is widely used by car manufacturers for its advantages particularly in fuel economy. Nevertheless, this CVT currently applies a hydraulic-based actuation system to change and to maintain the desired CVT ratio which leads to reduction of CVT's efficiency due to engine's continuous power consumption. To address this issue, a prototype of electro-mechanically actuated CVT is introduced in this paper. Here, the prototype's working principle is explained and the process to evaluate its workability is described. This evaluation process is necessary to provide reference data for future development of the prototype especially in the areas of ratio control and belt's clamping force control. The evaluation's results suggest that the prototype has a ratio range from 2.93 to 0.67 with using only one DC motor to vary the ratio instead of typically two DC motors used by previous designs of electro-mechanically actuated CVT.