Study On Pulley Deformation And Metal V-belt Misalignment Of CVT

The metal belt Continuously Variable Transmission (CVT) is supposed to be theideal vehicle transmission. It can continuously adjust the ratio to adapt to the changingof vehicle loads, best match transmission and engine and improve the economy ofvehicles. Recently, with the development of China’s auto market, more and moreautomobiles are equipped with CVT and it has become the trend of transmissiondevelopment. As the key components of CVT, Metal belt and pulley carry out torquefrom engine. Deformation of the pulley and misalignment of the metal belt lead toeccentric wear of metal belt, which impact the changing of ratio and the transmissionefficiency significantly.In this paper, the working principle of CVT is analyzed in detail and thegeometric model and mechanics model are derived, which provides the theory for thefollowing research. Secondly, the effects of the ratio, axial force and input torque onthe axial deformation of driving pulley are analyzed based on finite element method(FEM), and the result is verified by experimental data. According to the FEM result,the mathematic model about the axial deformation of driving pulley, ratio and the inputtorque in actual operating conditions is developed, providing a principle for pulleydesign and CVT efficient research. Then, the misalignment model of metal belt isillustrated. Comparing the misalignment models; BOSCH model is supposed to be theoptimal model. Furthermore, the pulley deformation is applied to the analyzedmisalignment of metal belt; The CVT misalignment curve under different pulley axialforce is obtained. Moreover, the effects of changing of the pulley angle and the centerdistance on CVT misalignment are analyzed. Finally, the strength of the metal V-blockwith maximum misalignment is analyzed based on finite element software and thedistribution of the stress is obtained, and the FEM result is verified by the experiment.These results provide significant reference for analyzing the failure mechanism ofpulley and metal V-block, optimizing the CVT misalignment and improving theefficiency of CVT.