A double planetary gear train-CVT transmission with multiple applications

摘要

A family of transmission systems based on a "Planetary Gear-CVT" mechanism is presented here. The systems considered consist of two compound planetary gear trains connected through a CVT pulley system to provide the power/torque split and recirculation function, without the use of additional clutches and/or chain drives. A two degree of freedom system results in which one of the degrees of freedom is directly related to the CVT ratio. The mechanisms considered here combine the gear reduction function of compound planetary gear trains with the continuously variable transmission ratio function of a CVT system, which is used as a circulating power control unit. The kinematics and dynamics of this family of systems is presented with emphasis on the belt forces, torques on the various shafts and the overall input/output velocity ratios through the CVT ratio span. Then a parametric analysis is conducted to characterize the effect of the various functional ratios and parameters of the system in terms of the overall performance. Finally, various potential applications are discussed and the associated design configurations are presented. Specifically, some applications related to automotive auxiliary equipment and industrial equipment transmissions are presented.