A novel design of a thrust magnetic bearing with a cylindrical-shaped rotor

A thrust magnetic bearing having a conventional thrust magnetic disk is usually installed in five-degree-of-freedom controlled bearingless drive systems. The thrust disk has a larger diameter than a rotor diameter of the bearingless motor. Therefore, a geometrical shape of the rotating part becomes convex. The convex-shaped rotating shaft causes complicated assembly and disassembly processes and increases its peripheral velocity, which results in a limitation of a maximum rotational speed. In this paper, a thrust magnetic bearing having a cylindrical-shaped rotor has been proposed and designed by using finite element method. The simulated results have shown that the proposed thrust magnetic bearing employing a permanent magnet rotor and a coreless coil stator has a sufficient thrust force.