Analysis of radial stiffness characteristics of deep groove ball bearing considering centrifugal effect under elastohydrodynamic lubrication

Abstract The rotor system’s vibration is influenced by the stiffness of high-speed deep groove ball bearings, with their radial stiffness affected by the oil film and centrifugal effect in elastohydrodynamic lubrication. To explore the influence of their combined action, the comprehensive radial stiffness calculation model of deep groove ball bearing is constructed and calculated by MATLAB software. An analysis is conducted on the individual and combined impact of radial stiffness under various viscosity, speed, and load conditions, considering the effects of the oil film, centrifugal force of the rolling body, and centrifugal expansion of the inner ring. The influence of bearing ball size on radial stiffness is obtained. The findings indicate that with the enlargement of the ball size, the comprehensive stiffness also increases. The viscosity reduces the synthetical stiffness, and the synthetical radial stiffness declines as viscosity rises. An increase in rotating speed results induce a decrease in stiffness due to the coupling effect, however, the centrifugal expansion causes the stiffness to rise as the rotating speed increases. In addition, under single factor and coupling conditions, the increase in the applied load results in a rise in radial stiffness.