Abstract:In order to verify the feasibility of a new automobile continuously-variable-transmission,the ball-type roller traction continuously-variable-transmission(BVT),a functional formula was built by using the Hertz contact theory and the basic theory of friction transmission. The transmission and contact characteristics of the BVT were analyzed by using the iterative solution method through simulating the vehicle operation condition. The calculation results show that the offset of pure rolling point in the BVT input and output contact area is increased with the increase of input torque. And regardless of the input torque, the offset of the pure rolling point in the input contact area is greater than that in the output contact area. The influence of traction coefficient on the sliding rate is very obvious in all working conditions of BVT, and the sliding rate of BVT is decreased with the increase of the traction coefficient. The result shows that the BVT has the advantages of constant transmission coefficient, small contact stress, low sliding rate and high contact friction efficiency. The favorable contact friction efficiency is comparable to the existing vehicular traction CVT. The feasibility of BVT design principle was verified from the aspect of transmission performance.