Multiple-degree-of-freedom dynamic model of rolling bearing with a localized surface defect

It is well known that the dynamic response of the rolling bearing would change especially in the acceleration vibration signal when the defects occur. To accurately simulate the dynamic response of a high-speed rolling bearing with a localized surface defect, we propose a new dynamic model for the faulty rolling bearing. The proposed model considers not only the high-speed effect of the rolling element, such as centrifugal force and gyroscopic moment, but also the degrees of freedom (DOFs) of all movable components, including five-DOF inner raceway, three-DOF balls and three-DOF the cage. Then the fourth order Runge-Kutta algorithm is used to solve the nonlinear differential equations of the model for obtaining the dynamic response of the bearing. Under different radial forces, rotational speeds and defect sizes, the acceleration vibration response of inner raceway and the motion of cage considering the effect of the localized surface defect are respectively analyzed. Finally, the correctness and effectiveness of the proposed model are proved by the measured signals of the faulty aero-engine spindle bearings.