On the Natural Frequencies of High-Speed Spindles with Angular Contact Bearings

Abstract

Experimental evidence has shown that the natural frequencies of a high-speed spindle decrease with increasing rotational speeds. While this phenomenon is important to the design and operation of high-speed machine tools, it has not been thoroughly analysed. This paper presents a spindle model that can be used to analyse the changes in bearing stiffness and the natural frequencies of the system. It is shown that the system dynamics can vary substantially due to bearing centrifugal force and shaft gyroscopic effects. The findings can be utilized in optimizing the design and control of high-speed spindle systems.