Dynamic analysis for deep grove ball bearing under grease elastohydrodynamic lubrication

The dynamic characteristic of grease-lubricated deep groove ball bearings for driving motors is one of the cores that affect the service performance of new energy vehicles. To investigate and improve the bearing stability, a dynamic characteristic analysis model of the bearing which introduces the grease-film stiffness and damping coefficients for a single contact pair between the rolling element and raceway is established. On this basis, the effects of grease, bearing operating conditions, and cage structural parameters on the bearing stability are examined. The results indicate that the presence of grease film improves the bearing stability to a certain extent. As the inner ring speed increases, bearing stability initially rises and then falls. In contrast, with increasing axial load or decreasing radial load, bearing stability improves. Moreover, as the cage pocket diameter or the cage thickness at inner bottom increases, bearing stability shows a trend of first rising and then falling, while an increase in the beam width of the cage leads to improved bearing stability.