Traction and Efficiency Performance of Ball Type CVTs

This paper concerns the design and analysis, of a ball type continuously variable transmission, (B-CVT). This B-CVT has a simple kinematic structure, and same as a toroidal CVT, transmits power by friction on the contact points between input and output discs, that are connected to each other by balls. After, a brief introduction of our B-CVT structure, the performance and traction efficiency of B-CVT is analyzed. The geometry and speed ratio of the proposed CVT is obtained. Then, by finding the contact areas between rotating elements and stress distribution through them, the torque capacity of B-CVT is computed. Next, the power loss of the system caused by various parameters such as relative arrangement of rotating elements as well as relative velocity at contact areas is found. Finally, after presenting the influence of the different geometrical and assembly conditions at efficiency of the system, the efficiency of the system compared with the efficiency of a Toroidal CVT.