Abstract
The low-efficiency problem of the rubber V-belt CVT system at the normal operating condition has not been significantly improved up to the present. In order to solve this problem, especially to decrease the bending hysteresis loss, the purpose of this research is to design a new chain-type CVT on the premise of preserving the advantages of the rubber V-belt. This proposed chain design features a roller chain with the barrel-shaped outer surfaces of both the inner- and outer-chain plates. The rubber layer is coated on the surface of the barrel-shaped chain plates to maintain direct contact with the pulley. By observing the motion characteristics of this chain-type CVT, a mathematical model is constructed for analyzing the force distribution and identifying power-loss mechanisms of the CVT. Furthermore, a parametric study for evaluating the performance of the new design is conducted and its torque and efficiency range is predicted. For the purpose of designing a reliable chain-type CVT, the stress distribution over the chain elements is analyzed by employing ANSYS software. Finally, by measuring the torque, rotation speed, belt tension and the variation of radius via a dynamometer, the effectiveness of the mathematical analysis is verified and the feasibility of the new design is preliminarily justified.