Effect of rotor eccentricity on the dynamic performance of a traction motor and its support bearings in a locomotive

Abstract

Rotor eccentricity is a common fault of traction motors during operation. To ensure the stability and safety of the traction motor, it is essential to analyze the effect of rotor eccentricity on the dynamic performance of the traction motor, particularly the motor bearings. This study focuses on the extraction of the fault vibration features of a locomotive in the presence of rotor eccentricity under complex internal and external excitations from the traction power transmissions and wheel-rail interactions. A spatial locomotive-track coupled dynamics model with an eccentric rotor motor is applied in this study, and the detailed mechanical structures of the traction motor and motor bearings are comprehensively considered. The results indicate that rotor eccentricity can deteriorate the vibration conditions of the traction motor and intensify the interactions between the components of the motor bearings. Due to the effect of the time-varying mesh forces, the variation in the loaded region of the non-driving end bearing is more significant than that of the driving end bearing.