The Flow Field Simulation of a Novel Water-Lubricated Hybrid Bearing for High-Speed Spindle

Abstract

A shaft of spindle with high speed and high stiffness could be stuck due to overheat generated by bearing and poor lubrication, and then the failure of spindle may occur. It should be seriously considered as a key factor for the bearing design of high-speed and high-stiffness spindle in order to increase the flow rate within the bearing with small clearance. A water lubricated hybrid bearing with multi-holes and deep/shallow recesses is proposed in the paper, which can be used in high-speed machine tool spindle. The FLUENT software is used to simulate flow field inside of bearing. For a compute time efficiency, a one-eighth bearing model is built for CFD analysis according to the bearing symmetry. The results show that, inlet and outlet oil ports could be placed in the same deep recess. Lubricant flowing into deep recess through the orifice restrictor could work appropriately for lubrication purpose of high-speed bearing, but not directly flowing out of outlet in the same groove as many people assumed. The remarkable turbulence flow occurs for lubricant in deep recess and gradually weakens in the shallow recesses.