Dynamics modeling on local defect of deep groove ball bearing under point contact elasto-hydrodynamic lubrication condition

The traditional bearing dynamics models are mostly based on dry contact mechanics, in which the effect of lubrication on bearing vibration has not been taken into account. The contact stiffness of the bearing will be affected due to the existence of lubricating oil film between the raceway and ball with local defect. Taking into account the relationship among the contact deformation, radial clearance and the defects, a simulation method for local defects was presented. Then, a two degrees of freedom dynamic model of the deep groove ball bearing was constituted with consideration of the nonlinear Hertzian contact deformation and the influence of elasto-hydrodynamic lubrication on the bearing contact stiffness. The model can simulate the actual condition of bearing operation more accurately. Comparing the signals of vibration responses in the simulation with the experiment data of actual fault bearings, the correctness of the model was verified. It could provide a theoretical foundation for fault diagnosis of bearing. © 2016, Editorial Office of Journal of Vibration and Shock. All right reserved.