Research on ball bearing stiffness considering the uncertain bearing-shaft interference fit

Bearing-shaft interference fit is very sensitive to the service performance of ball bearings, in recent years, scholars have taken this factor into consideration during the modeling process of ball bearing. However, the uncertainty in bearing-shaft interference fit is inherent due to the tolerance in the manufacturing process and the effect on the service performance of ball bearings has not been paid much attention by scholars. Moreover, the interference fit amount could change due to the influence of centrifugal force, which could influence the bearing stiffness. Therefore, this paper presents a non-intrusive stiffness model of ball bearing based on quasi-static model combined with the Chebyshev interval analysis method, in which the bearing-shaft interference fit model with uncertain parameters is incorporated. The effect of the average value and deviation coefficient of the interference fit on the bearing stiffness versus time, preload and rotating speed under different preload mechanism are investigated. The experimental results from the published works are compared to the present results to verify the validity of the bearing stiffness model. Then the Monte Carlo simulation (MCS) is conducted to validate the accuracy of the proposed method. The model and method used in this paper can better elucidate the fluctuation of the stiffness induced by the uncertain bearing-shaft interference fit, and provide theoretical guidance for the design of the rotor-bearing system.