Invetigation Into The Efficiency Optimization Of Push Belt Continuously Variable Transmission

As the fossil energy resource decreasing in the world and the environmental problem caused by the fuel consumer, the governments have had to increase the constraints of emission and fuel consumption which vehicle must meet. As the pressures of these constraints mount, the focus of the vehicle company has concentrated on improving the efficiency of the automobile. The transmission plays an important role in the efficiency of the vehicle, and CVT as one important technology of the transmission, it has practical significance in improving the efficiency of the CVT.Based on other people’s research, the power lose of the CVT are mainly separated into four parts, including the power lose of torque convertor, DNR clutch system, oil pump and the variator.This thesis investigates and models the power loss of the CVT based on the QR019 CVT running under the NEDC test cycle. It mainly analyzing and modeling the power loses of the oil pump and the variator according to the CVT specs, like the pulley pressure,the friction between pulley and belt, the pulley angle and so on. The power lose of the oil pump and the pulley set are measured on the special test benches according to the specs which the parts are running under the NEDC cycle, and the test results are used to recalibrate the models. Finally some proposals are made to improve the efficiency of the CVT, based upon the findings of the models.The efficiency of the QR019 CVT is obviously improved after applying some of the proposals. The results show that the analytical approach and the improving proposals for the CVT efficiency presented by this thesis have Practical significance.