Design of Radially-Differential Type Magnetic Harmonic Geared Motor

A magnetic geared motor has been developed as a low speed and high torque motor. However, it is difficult to increase the gear ratio due to the constraint of the number of poles. In order to solve this problem, a radially-differential type magnetic harmonic geared motor is proposed. It can easily increase the gear ratio up to approximately several hundred. In this paper, the structure and operational principle are described. Finally, the torque characteristics are investigated using 3-D finite element method (FEM).