Abstract
A power-split half-toroidal CVT, consisting of a variator and planetary-gear set, has features of stretching the speed-ratio range and decreasing the transmitting torque through the variator in high-speed cruising mode, while it has two issues of inversion of torque flow through the variator and discontinuity of output torque during mode change from direct to power-split mode. This paper confirms its inversion of torque flow by measuring the transmitting torque on the re-circulating shaft of the CVT-Box with speed ratio range of 1:6.33, and solves both the torque discontinuity and the torque-surge by a sequential control of variator-ratio and engaging pressures of a pair of mode-change clutches.
