Study on Lubricating Performance of the Bubbly Oil Under High Shear Rate—Part 2: Application Study in High-Speed Bearing

Abstract This paper aims to investigate the lubricating performance of the bubbly oil. Due to space limitation, the work is divided into two parts. Part 1 concluded that the bubbly oil under high shear rate has a lower viscosity than the non-aerated oil, and the air volume fraction can be adjusted conveniently to reach a high value. Based on this, in Part 2, we intend to explore the feasibility of using the bubbly oil in lubricating high-speed bearings. Here, we select a step thrust bearing as object and analyze its static characteristics under the bubbly oil lubrication. A test rig for the high-speed step thrust bearing was developed to measure the static characteristics of the bearing under the bubbly oil lubrication. The lubrication models for the hydrodynamic step thrust bearing were established to predict the bearing static characteristics. The results show that the static characteristics parameters of the bearing under the bubbly oil lubrication are less than those under the non-aerated oil lubrication, and the differences of static characteristics parameters of the bearing between the non-aerated oil lubrication and the bubbly oil one become larger with the increase of air volume fraction and the external load, especially at a higher speed.