Influence of Traction Motor Components on Thermal Characteristics of Traction Motor Bearings

Abstract

The operating temperature and thermal stress play key roles in overall performance of a cylindrical roller bearing used in high-speed train traction motor. The cylindrical roller bearing studied in this paper is in the housing of the traction motor. Due to the heating of each component of the traction motor, a thermal environment is formed in the housing that changes the temperature and stress of the traction motor bearing. In this paper, a thermal-mechanical coupled model of bearing considering the stator, rotor, and shaft was established to study the temperature and thermal stress of traction motor bearing. Experiments were conducted on a service high-speed train to validate the proposed bearing thermal analysis model, meanwhile, the temperature of the measurement point was revised by the theory of heat transfer. The revised experiment results show that the established thermal-mechanical coupled model is reasonable and effective. The results show that the heating of the stator and rotor of the traction motor has a great influence on the temperature and stress of the cylindrical roller bearing of the traction motor. When the heating of the stator and rotor is considered, the temperature of inner ring near the traction motor is higher than that of far away from the traction motor, and the overall temperature of each component of the bearing also increases. As for the stress, when the traction motor stator and rotor is considered, the maximum stress increases by 66.9%. Therefore, the heating of the stator of the traction motor must be considered when the thermal characteristics analysis and reliability analysis are carried out on the cylindrical roller bearing.