In Situ Visualization and Analysis of Oil Starvation in Ball Bearing Cages

Abstract This article presents an investigation into oil starvation in different cage pocket shapes of a horizontally mounted ball bearing. A counter-rotating angular contact ball bearing test rig (CRACTR) was used to visualize the oil distribution inside specially manufactured transparent bearing cages using detailed images from a high-speed camera. Three different cage types were investigated using various oils dyed with ultraviolet dye. The identification of oil and air regions elucidated the oil distribution in the cage pocket and the formation of oil–air striations on the ball surface under various operating conditions. The experimental results demonstrated that raceway motion, ball submersion level, oil properties, and cage pocket shape influenced oil starvation inside the bearing cage. ANSYS Fluent software was also used to develop an equivalent two-phase computational fluid dynamics (CFD) model for the test bearing. Results from the CFD model corroborate well with the experimentally observed oil distribution for all test cages and establish the strong influence of cage geometry on oil starvation and bearing lubrication. GRAPHICAL ABSTRACT