Abstract: Magnetic bearings are often used in high-speed occasions. The limit speed of traditional ball bearings is low, which becomes the key factor restricting its reliability as a backup bearing. Taking the single-decker hybrid ceramic ball bearing as the object, the dynamic process of the high-speed rotor dropping to the backup bearing after the loss of power of the magnetic bearing is analyzed, and the change law of the bearing speed is obtained; then, the speed distribution of the double-decker bearing is studied compared with the single-decker bearing, and the speed improvement is analyzed. Through the performance analysis of the double-decker bearing, it provides a reference for the design of high reliability backup bearing for magnetic bearing system.

Key words: Magnetic bearing, Backup bearing, Double-decker ball bearing, Dynamic analysis, Rotational speed analysis