Impact of Inclination of Teeth for Bearingless Motor with Non-contact Power Supply

A new type of bearingless motor has been developed. The feature of this bearingless motor is no use of permanent magnets. The rotor is magnetized by a current of a non-contact power supply, which consists of a bridge rectifier circuit and coils. Levitation is achieved through attractive forces generated by inclinations on the edges of the rotor and the stator. In the previous study, levitation of a prototype system could not be achieved. It was posited that the inclination of edges decreases restitutive force, which is used to control the tilting motion of the rotor. In this paper, the impact of the inclination of the edges on the decrease of restitutive force was investigated and confirmed by 3D-FEM analysis. Additionally, levitation of the prototype system was investigated by simulating the displacement of the rotor with both linear and non-linear rotor models. Finally, the control principle was changed according to findings of this study and the controllable range of the rotor was calculated.