Comparison of Two Different Interior Permanent Magnet Type Low-speed Rotor Structures of Axial-Flux Magnetic Gear

Magnetic gears are expected for practical use due to their attractive features such as low vibration and maintenance-free because of no mechanical contacting torque transmission. Among them, a flux-modulated type magnetic gear has higher torque density than the other types. In previous papers, it was verified that an interior permanent magnet (IPM) structure rotor can reduce eddy current loss in magnets. This paper investigates that the IPM structure is applied to an axial-flux magnetic gear (AFMG). Two types of IPM low-speed rotor structures, one is a spoke-shape and the other is a segment-shape, are compared in terms of torque and efficiency.