A Bearingless Synchronous Reluctance Slice Motor with Rotor Flux Barriers

This paper presents a bearingless synchronous reluctance slice motor, which contains no permanent magnets. The rotor with four iron poles and flux barriers is levitated and rotated through a stator winding system with six coils wired as two three-phase systems. After applying a constant rotor oriented magnetization current, the system can be controlled just like a bearingless permanent magnet synchronous slice motor, including the passive stabilization of axial and tilting movements. In a first step, the motor geometry is being optimized and the performance characteristics of the designed motor are examined. The motor is then compared to two other designs, which contain permanent magnets either in the rotor or the stator. The comparison includes torque generation, radial force generation, passive axial and tilting stiffnesses and wide air gap suitability. The introduced topology outperforms the others for ultra high process or ambient temperatures and rotor disposable applications with a short exchange interval.