Abstract
This paper introduces a tilt-controlling axial self-bearing motor with a single stator. The motor consists of a stator and a disc rotor and is capable of controlling motor torque, axial position and tilt angle. The stator has six coils, which are driven by separate amplifiers. The rotor has two or four magnetic poles. By adding two types of currents (a motor current, which has the same poles as the rotor, and a tilt control current, which has plus two or minus two poles of the rotor) four degrees of freedom of the rotor can be actively controlled. The motor torque, axial force and tilt moment are theoretically analysed and a control method is shown. A prototype using a superconducting radial magnetic bearing is fabricated and tested to study the feasibility of the proposed motor. Results show that the motor can levitate and rotate, but the radial force produced by the tilt control current, and tilt moments coupled with the motor control current, cause stability problems.