Study on the Thermal Performance and Temperature Distribution of Ball Bearings in the Traction Motor of a High-Speed EMU

Abstract

The transient thermal performance of rolling bearings affects the mechanical performance and system safety of traction motors. Most of the traditional empirical formulas used in temperature analysis have been simplified and cannot be completely applied to the calculation of heat generation and convection heat transfer coefficients. Based on the comparative analysis of finite element transient temperature and experimental data, this paper proposes a correction method of mathematical model and derives an accurate calculation formula for the heat generation and lubricant convection heat transfer coefficient of ball bearings applicable for the non-driving end in the traction motor of a high-speed EMU (Electric Multiple Unit). The accuracy of the results has been verified by durability experiment data. In addition, with changes in speed, radial load and other factors taken into account, we have analyzed the influence of these time-varying factors on ball bearing temperature, as well as the temperature distribution law of each component in a grease-lubricated bearing, in a bid to lay a foundation for follow-up research on the heat transfer laws of traction motors and rolling bearings.

Numerical analysis on heat-flow-coupled temperature field for orthogonal face gears with oil–jet lubrication

“…The heat generation, Q bearing , of a rolling bearing is the product of the friction moment and angular speed (Wang et al, 2020):…”

Dynamic, thermal, and vibrational analysis of ball bearings with over-skidding behavior

“…The thermal performance and temperature distribution of rolling element bearings under various lubrication conditions were systematically studied. Examples include grease-lubricated ball bearings [28], roller bearings [29], spherical roller bearings [26], oil-air lubricated ball bearings [30], and oil-flood ball bearings [31]. The thermal network method and generalized Ohm's law are widely applied to discontinuous multibody dynamic systems.…”

Experimental Research on the Influence of Working Conditions on Vibration and Temperature Rise of Si3N4 Full-Ceramic Bearing Motors

“…Hot isostatic pressed silicon nitride (HIPSN) is considered to be the most suitable engineering ceramic material for bearings due to its low density, wear resistance, high rigidity, low expansion coefficient, self-lubricating, electrical insulation, and other excellent characteristics [10], and it has become a new direction for modern bearings and has become more and more widely used. ere are many reasons for vibration and temperature rise in ceramic bearings during operation, such as frequent changes of rotational speeds, loads, external environment and other factors, friction and wear between the internal components of ceramic bearings, fatigue spalling and crack propagation of ceramic rings and rolling elements, cage fracture [11], existence of bearing clearance, viscosity and friction resistance of lubricating oil [12], and so on. Applying proper axial preloads [8] to the bearing can not only reduce the axial clearance of the bearing but also improve the stiffness of the shaft system to reduce vibration and noise [13].…”

“…Researchers have made many contributions in the fields of shaft vibration and motor temperature rise: Wang et al [11] studied the thermal performance and temperature distribution of ball bearings in the traction motor, the influence of rotational speed and applied load variation on bearing temperature, and the temperature distribution law of each component in grease lubricated bearing are analysed. Jamadar and Vakharia [12] studied the effect of grease viscosity on mechanical vibrations associated with the damaged bearings, and the results show that when the grease viscosity is higher, the amplitude of the bearing presents a lower level, so the service performance of the bearing is improved.…”