抄録
The novel mechanism CVT (Shaft Drive CVT, S-CVT) was developed by the authors. To improve the efficiency of Shaft Drive CVT, the theoretical power-transmitted efficiency is examined in this paper. The power-transmitted efficiency is calculated from the torque-transmitted efficiency and the speed-transmitted efficiency. The torque-transmitted efficiency of Shaft Drive CVT, which is calculated from the loss torque of the bearings, is 85 to 83%. When the input torque is lONm, the speed-transmitted efficiency, which is calculated from a shear model of traction oil in EHL contact area, is 99 to 96%. Due to the greater adverse effect on the power-transmitted efficiency than the speed-transmitted efficiency, an improvement of the torque-transmitted efficiency is required immediately. But in case of input torque more than 25Nm imputed, the traction coefficient decreases due to the spin, and the speed-transmitted efficiency decreases to 92%. So as to transmit large torque in better efficiency, a reduction of spin is required.
