An Axial Magnetic Gear With Improved Torque Density and Reduced Cogging Torque

A new axial magnetic gear (AMG) with enhanced torque density and reduced cogging torque is proposed in this paper. In the new structure, the direction and width of permanent magnets in high-speed rotor are changed and permanent magnets are removed from the modulator while the low-speed rotor remains unchanged. The torque density of the proposed magnetic gear is enhanced by using an appropriate direction and pole pitch for permanent magnets of high-speed rotor. The proposed AMG is compared with recent structures in the literature with the highest torque density. Three-dimensional (3D) finite element analyses are employed to obtain the cogging torque and torque density. The results of the analysis indicate that not only torque density increases but also cogging torque decreases dramatically.