Improved Dynamics Model of Locomotive Traction Motor with Elasticity of Rotor Shaft and Supporting Bearings

Abstract

The locomotive traction motor is described as a rotor-bearing system coupling the kinetic equations of the traction shaft and its support bearings with the determination of their elastic deformations in this study. Under the effect of excitations induced by the dynamic rotor eccentric distance and time-varying mesh stiffness, the elastic structure deformations of the shaft and support bearings are formulated in the vibration environment of the locomotive. In addition, the nonlinear contact forces between the components of the rolling bearing, the lubricating oil film, and radial clearance are comprehensively considered in this study. The results indicate that the elastic deformations of the shaft and bearings can change the dynamic responses of the traction motor and its support bearings. There are large differences between the ranges of the rotor motion calculated by the rigid and the flexible traction motor models when the intensified wheel-rail interaction is considered. With the increase of the rotor eccentricity, the results underscore the role of the elasticity of traction shaft and support bearings in dynamic researches of the traction motor. The critical value of the initial eccentric distance for the rub-impact phenomenon decreases from 1.23 mm to 1.15 mm considering the flexible effect of the shaft and bearings. This dynamics model of the traction motor can provide more accurate and reasonable simulation results for correlational dynamic researches.

Dynamic Characteristics and Fault Mechanism of the Gear Tooth Spalling in Railway Vehicles under Traction Conditions

“…A gear is a key mechanical component of the traction transmission system of railway vehicles, and its research focuses mainly on operational status assessment and health maintenance [24][25][26]. The current research mainly uses a dynamic modeling approach to study its fault mechanism [27][28][29][30], nonlinear behavior [31][32][33], and impact on vehicle dynamics [34][35][36][37][38][39]. Zhang et al [40] proposed electromechanical coupling modeling to describe the interaction between the electrical and mechanical parts of the traction transmission system in a high-speed train.…”

Multispectral Balanced Automatic Fault Diagnosis for Rolling Bearings under Variable Speed Conditions

“…Automatic diagnosis of mechanical state based on sensor signals has attracted more and more attention in recent years [2]. Since most rolling bearings work in harsh variable speed conditions, such as motor bearings and axle-box bearings in high-speed trains, it is necessary to carry out bearing fault diagnosis under variable speed conditions [3,4]. Failure of bearings cause abnormal vibration and noise, which means that vibration signals of rolling bearings carry rich information about their states of health [5].…”