An Introduction of a New Traction Drive Pairing with the Inner and the Outer Surface of the Spherical Rotors for Automobile Usage 2004-40-0025

A new inner spherical continuously variable transmission (ISCVT) is introduced. The inner races of driving and driven spherical rotors are contacted with the outer surfaces of the associated counter spherical rotors respectively and two pressure devices(PD) of screw ball type generating the contact normal forces proportional to the transmitted torques are considered. A ratio changer assembly (RCA) using a cam mechanism also is developed and installed in the core region of the unit. To check out the practicability on the automobile usage, an automobile having a rated values of 110kw/6000rpm with 0.09~ 0.37 overall speed ratio (OSR) is conceptually designed by using the direct search method on the selected design variables optimizing the overall power efficiency and satisfying the design constraints on the limits of the overall diameter, the contact stresses, the fatigue life time based on the Lundberg-Palmgren theory. On the conceptually designed car, several transmission performances are simulated and discussed. Many fruitful features on the proposed model are shown by the simulations and the comparison with the typical toroidal CVT (TCVT).