New bearing model with flexible cage and study of dynamic behavior under variable-speed

Since rolling bearings frequently operate in variable speed conditions, the elastic deformation of the cage occurs intensely due to the enhanced excitation, which may lead to dynamic instability or even failure of the bearing. To this end, a flexible cage model based on the semi-flexible body element is developed in this paper. The force excitation from the ball and the guiding ring is considered to be applied to the cage. By coupling with the previous bearing model, a bearing dynamics model with flexible cage is presented. The results predicted by this model are closer to the experimental values than those of the rigid model. The differences between the two models in predicting the bearing dynamic performance under typical variable speed conditions are compared. The effect of preload on its dynamic behavior was further investigated with the flexible model. The results show that a slightly smaller radius of the cage orbit is predicted by the flexible model than that of the rigid model. Compared with the rigid model, more stability of cage motion is predicted by the flexible model. A similar phenomenon can be observed in the force excitation on the cage. There is not significant difference between these two models in predicting the velocity of the bearing assembly. The work in this paper provides a new idea for modeling flexible cages.