A novel design of a Lorentz-force-type small self-bearing motor

Although magnetic bearing motors suffer no friction loss and hence require no lubrication, they are not widely used because of their high cost and large size. To solve these problems, a self-bearing motor having a simple structure with distributed windings is proposed. The rotor consists of a permanent magnet and an iron yoke that rotates in the body. The stator consists of a six-phase distributed winding and is installed between the permanent magnet and the back yoke of the rotor. A Lorentz force, generated by the interaction between the stator current and permanent magnet field, controls the rotation speed and radial position of the rotor. In this paper, a novel design for a slotless self-bearing motor with two windings, and non-contact levitation capability, is introduced, and experimental results are shown.