Design and research of a novel magnetic-geared outer-rotor compact machine

A novel magnetic-geared outer-rotor compact machine is proposed, which integrates a magnetic gear into a brushless DC motor (BLDCM), so that they can share a common cup rotor, then the inner space of the magnetic gear is utilized adequately, thus the low-speed and high-torque is achieved in direct driving, and the high efficiency of the whole system is gained simultaneously. The time-stepping FEM is employed in the analysis of the compact machine for the first time. The coupling of the harmonic magnetic field in the machine is taken into account, thus the dynamic performances of the compact machine are obtained, then discover that the compact machine driving system is suitable for low speed high torque direct driving system with unsuitability of the comfort and precise applications. A prototype machine is tested. The experimental result confirmed the analysis results.