Evaluation of Support Stiffness of a Permanent Magnet Attractive Force Type Passive Magnetic Bearing

Magnetic bearings encompass superconductive, active, and passive types. Among the passive magnetic bearings, there are two categories: repulsion force type and attractive force type. The repulsion force type necessitates permanent magnets in both the rotor and stator, while the attractive force type requires only a single permanent magnet, thereby simplifying its structure. The stiffness of attractive force type passive magnetic bearings varies with the end shape of the rotor shaft; however, it remains unclear how this stiffness is affected by geometric changes, and an established evaluation method for stiffness has yet to be developed. In this paper, we validate the results obtained from finite element analysis through experimental verification to assess the impact of altering the shaft end shape.