An analysis of a thermally affected high-speed spindle with angular contact ball bearings

Abstract This paper discusses thermal effects on bearing stiffness, and consequently, the natural frequencies of a high-speed spindle system. Heat is generated due to friction torque at the contacts between the raceways and the balls of the angular contact ball bearings. In our experimental spindle system, the heat sources included six bearings and a built-in motor. Five-by-five bearing stiffness matrices were computed based on the thermal-mechanical parameters. The stiffness matrices were used as inputs for a finite element model generated in the ANSYS Workbench environment, in which the bearings were simulated as bushing joints, to compute frequency response numerically. The simulated results showed that the third natural frequencies decreased with increasing temperature and were in good agreement with the experimentation.