Research on the effect of structural and material parameters on vibrations based on quasi-static model of bearings

Variable compliance vibration is an inevitable source of the parametrically excited factors of rolling bearing–rotor system under the effect of only a limited number of rolling elements to carry the loads. Based on the quasi-static model of ball bearing, the mechanism of time-varying stiffness is studied and the effects of external load, rotational speed, geometric structure of the bearing and material parameters on the time-varying stiffness and relative variation of stiffness are analyzed quantitatively. Results show that load redistribution in bearing caused by the change of ball spatial position is the direct cause of the time-varying stiffness. Rotational speed, the number of balls and diameter have great effect on varying compliance vibration compared with external load and material parameters. In order to reduce the vibration, axial preload, contact angle, ball diameter and density should be appropriately increased, raceway groove curvature radius and radial load should be reduced, and the optimal number balls and rotational speed can be obtained according to the single-variable optimization method. The results provide theoretical basis for the structural design, material and manufacturing process selection.