Theoretical and experimental approaches for flexible cage dynamic characteristics of four-point contact ball bearing considering multi-point contact behaviors

Multi-point contact often occurs between the balls and raceways of the four-point contact ball bearing (FPCBB) due to operating conditions and manufacturing errors, which can lead to unstable motion and wear of the cage. A dynamic analysis method for FPCBB with a flexible cage under multi-point contact is presented in this paper. Initially, the boundary conditions for different contact points (two-point, three-point, and four-point contact) are clarified through the research of the dynamic interaction and collision mechanisms between the balls and the raceways. Subsequently, based on the structure flexibility, and the collision effect among the balls, cage, and guiding ring, a dynamic model for FPCBB is constructed, and the heightened accuracy and superiority of the model are substantiated through comparative analyses with the conventional rigid cage model. Furthermore, the influence of operating conditions and manufacturing errors on the rotational stability and the wear degree of the cage are explored, and the accuracy and reliability of the model are experimentally verified. The results show that the degree of cage wear is strongly influenced by the contact state, and the maximum wear degree varies at different positions. Reasonable speeds, loads, and manufacturing error range can effectively improve the contact conditions, thereby augmenting cage motion stability and mitigating wear. This research contributes novel insights into the failure analysis and structural optimization of the FPCBB.