Characteristic analysis on a new hydro-mechanical continuously variable transmission system

A new continuously variable transmission (CVT) system is proposed in this paper for the purpose of improving transmission efficiency in vehicles. The proposed system consists of a power-cycling hydro-mechanical transmission structure characterized by stepless speed regulation. In this paper, the working principle of the new CVT system is first expounded. Thereafter, the basic characteristic formulae derived in this study for speed ratio, torque, and efficiency are reported. As a significant torque ratio is obtained when the speed ratio is zero, the new CVT system provides more advantages in terms of numerous important aspects compared with other existing forms of transmission. Finally, the effect of the gear shift device, which is in a different transmission path relative to the new CVT was analyzed, and appropriate transmission structures under different operating conditions were identified.