Effects of interference fit variation on dynamic characteristics of full ceramic ball bearing rotor system

Bearing fit is one of the key aspects in determining the performance of FCBB (full ceramic ball bearing), which affects FCBB internal contact condition and support stiffness. In this paper, the interference fit value variations of FCBB induced by the centrifugal displacement and thermal deformation is calculated, the mapping relationship between interference fit and internal clearance is established, and the influence of preload and interference fit value on the dynamic characteristics of FCBB is discussed in detail. Finally, the vibration experiment of FCBB is verified by ABLT-9 bearing life testing machine. The research shows that interference fit value is the main factor affecting internal clearance. The increase of internal clearance will reduce the bearing radial stiffness and increase the non-uniformity of load distribution, while the preload will weaken the influence of internal clearance on radial stiffness and load distribution. The results provide a theoretical basis for improving the FCBB's service performance and optimizing their assembly parameters.