Loss analysis and performance improvement of trial SPM type magnetic gear

Magnetic gears are becoming attractive since they offer advantages such as low vibration and acoustic noise, and low maintenance operation in comparison with conventional mechanical gears. Planetary type magnetic gears, especially, have larger transmission torque than the other types. Therefore, the planetary type magnetic gears are expected to be put into practical use. In this paper, first, torque characteristics and efficiency of a planetary type magnetic gear with surface-mounted permanent magnet (SPM) are calculated by finite element analysis (FEA). Next, experimental results of a prototype magnetic gear manufactured on the basis of the FEA results are indicated. Finally, efficiency improvement of the prototype gear is demonstrated based on the FEA and experimental results. The improved prototype gear has achieved high efficiency of over 90%.