Radial clearance directly affects the distribution of two-phase flow and the thermal characteristics of angular contact ball bearings.In order to explore the thermal characteristics of oil-gas lubrication two-phase flow in angular contact ball bearings under different radial clearance,a numerical analysis model was established based on two-phase flow theory and bearing heat transfer mechanism to simulate the flow characteristics of oil-gas two-phase flow in bearing cavities,and to analyze the effects of radial clearance and bearing operating conditions on the flow field distribution and temperature rise in bearing cavities.The simulation results was verified by the bearing temperature rise test results.The results show that the oil phase is mainly distributed in the bearing outer ring under the influence of centrifugal force,and the increase of radial clearance reduces the volume fraction of oil phase.Bearing temperature rise decreases with the increase of radial clearance,and increasing radial clearance can reduce bearing heat generation to a certain extent.The research results provide a reference for exploring the oil-gas lubrication thermal characteristics of angular contact ball bearings and improving the structural parameters of the bearing cavity.