Nonlinear dynamic model of ball bearings including all of bearing parts with full degrees of freedom and its advancement compared to past dynamic models

Abstract A novel dynamic model of ball bearings including all of bearing parts with full degrees of freedom is developed, in which the relative positions of bearing parts are used to calculate iteratively the real-time lubrication effects, interaction forces, dynamic behaviors, spatial positions and relative motions of bearing parts. Besides, cage is sliced to establish the dynamic equations of cage with six degrees of freedom for evaluating the interaction between balls, cage and guiding surface. The time-varying contact loads and contact angles induced by the time-varying relative positions of bearing parts are adopted to calculate the dynamic equilibrium of inner ring for obtaining the trajectory of inner ring in a certain space. On this basis, the dynamic behaviors of this novel model are compared with that of the past dynamic models. The results show that this novel model is more consistent with the engineering practice with respect to the past models.