Numerical and experimental investigation of the stratified air-oil flow inside ball bearings

The lubrication and cooling design is important for high-speed rolling bearings. A multiphase numerical simulation and the corresponding tests were conducted to investigate the stratified air-oil flow inside jet cooling ball bearings. The simulated results of the volume fraction distribution has the same trend with measured observations. The heat transfer was also considered. It was found that the temperature distribution of the bearing was affected by the volume fraction distribution. The higher temperature always appears in the lower oil volume fraction region. The conventional oil-jet lubrication mechanism cannot achieve an efficient cooling on the inner ring of the high-speed ball bearing. The oil volume fraction increases with an increasing nozzle number. The number should not be larger than six for increasing the oil volume fraction. The jet velocity and the oil flow rate have great effects on the average oil volume fraction inside the bearing rather than the oil volume fraction distribution around the circumference. The flow pattern inside the jet-cooling ball bearing is significant for its temperature forecast and control.