Dynamic modeling and analysis of traction motor bearing for railway vehicles

Railway vehicle traction motor bearing is an important rotating support component. The complex contact, collision, and impact between the internal components during its high-speed operation is an important source of fatigue damage to the raceway surface, cage breakage and motor vibration noise. In-depth understanding of the dynamic characteristics of the internal components during the operation of traction motor bearings is important to improve the design, operation and maintenance of this key component. In this paper, the cylindrical roller bearing of a traction motor was first taken as the research object. Based on Lagrange multi-body dynamics method and the Hertz contact theory of coupled energy dissipation, and by considering the transient dynamic effects of bearing components, the dynamics model of the traction motor bearing for railway vehicles was established. Then, the accuracy of the model was verified by comparing with the results calculated via the classical Harris theory. Finally, the dynamic characteristics of a certain type of railway vehicle traction motor bearing were analyzed under the working conditions of different rotational speed, load, and radial clearance. It is found that when the rotational speed is low and radial load is small, the contact load distribution of the roller in the bearing area shows more obvious fluctuations. With the increase of rotational speed and radial load, the fluctuations of contact load distribution of the roller in the load bearing area tend to level off. When the rotational speed is low and the radial clearance is large, the inner ring mass center orbit develops towards the disorderly state and had obvious fluctuation. When the rotational speed is high and the radial clearance was small, the inner ring mass center orbit is stable and its regularity is improved. As the rotational speed increased, the range of the inner ring centroid trajectory is expanded. When the radial clearance increases, resulting in the roller stress of load bearing area gradually increases, the interaction force between the roller and the inner ring significantly increases, so that the acceleration in the vertical direction of the inner ring become larger, the range of the inner ring mass center motion become larger, as well as its disorder increases. © 2023, Central South University Press. All rights reserved.