Design study for exterior rotor bearingless permanent magnet machines

This paper describes important design considerations for a bearingless brushless motor in exterior rotor construction. In order to come up with a compact, energy-dense setup which can provide both bearing forces and high torque, several parameters have to be accounted for while considering mutual dependencies. Moreover, the magnetic bearing and the drive are interlinked for this disk-shaped bearingless motor (with combined concentrated windings). A detailed analysis about the design of the stator teeth has been undertaken and the influence on torque and active and passive radial forces has been investigated.