Development of a simple determination method of variable preloads for high speed spindles in machine tools

The variable preload technologies and methods, which can select an optimal preload which maximizes the performance of a spindle system and bearings, are most important. This study proposes a new and very simple variable preload determination method that specifically configures the optimal preload according to the purpose of spindle systems. Based on the service life, stiffness, and gyroscopic slip in bearings, this study proposes an algorithm that is able to determine the optimal preload by considering the number of rotations of a spindle and external loads simultaneously. Also, a quasi-dynamic analysis program for rolling bearings is used to implement the algorithm. By using the developed bearing analysis program and proposed preload determination algorithm, this study determines the optimal preload according to the number of rotations in a single specific case that represents the internal shape information of bearings.