Study On Transmission Characteristics Of Rubber V-belt CVT

Rubber V-belt CVT has been extensively applied in low-power vehicles, such as snowmobiles and ATVs due to its incomparable advantages of smoother speed ratio change, high speed-ratio range at the rated speed, a simpler mechanism with low cost and less maintenance, etc. The matching and optimization of main structure parameters of CVT , which is the key technology for Vehicle development , directly affect vehicle ride comfort, dynamical and economical performance. Both theoretical analysis and experimental study of CVT are analyzed to investigate the operating principles, shifting and transmission characteristics. Then parameters modification methods of CVT parts are proposed to obtain the optimal scheme.The study work has been completed as follows:①Basic structure and operating principle of rubber v-belt continuously variable transmission are analyzed, and the kinematic relations are developed.②The mechanical analysis of a rubber V-belt CVT is conducted. Through the theoretical analysis, the mathematical model of the system running in steady states is derived and then carried out on a Matlab platform by the Gauss-Newton iterative method to obtain the kinematic relations and force behavior of CVT under various operating conditions to analyse the relationship between speed, torque and ratio.③Shifting characteristics and transmission efficiency of rubber v-belt CVT are analyzed. Combining with the ideal operating characteristics curve, the effect of parts parameters on shifting characteristics are analysed. Then engagement speed, ratio coverge, top speed and carrying capacity of rubber v-belt CVT are investigated to discuss the key parts parameters effect on transmission characteristics. At last, optimal scheme is obtained by comparing different multi-parameters optimum schemes .④A test rig has been constructed to study shifting characteristics,transmission efficency and carrying capacity on rubber v-belt CVT. Acooding to the demand of snowmobile running performance, the optimal scheme is obtained by consdering riding comfort,the dynamic and economic performances.⑤Adjusting schemes of rubber v-belt CVT parameters matching are proposed.