Effect analysis of cardan shaft misalignment on dynamic performance of high-speed vehicle

Abstract

In order to reduce the upsprung weight, cardan shaft is used in Chinese high-speed vehicles CRH5 to transmit torque from the motor to the wheel pair. The cardan shaft becomes misaligned due to worn wear pads in the cardan joint and shifting of the cross shafts. The misalignment results in inertia force and affects the vibration of the wheel pair and the carriage. A dynamic model of the vehicle including cardan shafts is proposed in this study to analyze the effects of the misalignment on dynamic performance of the vehicle. A route is designed based on European Railway Standard EN14316 to perform the simulation. Effects of the misalignment on wheel-rail contact force and acceleration of the carriage are investigated through simulations. Dynamic performances including driving safety and riding comfort of the vehicle under different shifting lengths of cross shafts are studied through the calculation of the derailment coefficient and the riding comfort index. Transmission efficiency of the cardan shaft with respect to different shifting lengths of the cross shafts under different speeds of the vehicle are studied. Threshold of shifting length of the cross shaft is determined in this study to avoid reduction of riding quality of the vehicle based on the standard of riding comfort index of vehicles, and the spectral amplitude of acceleration of the motor with respect to rotating frequency of the cardan shaft are calculated for maintenance of the cardan shaft.