Performance Investigation and Experimental Testing of a Stator-PM-Excitation Axial-Flux Magnetic Gear

This article proposes a stator-excitation axial-flux magnetic gear (SEAMG) based on innovative improvement from rotor excitation to stator excitation for the magnetic gear (MG). The key design of the proposed SEAMG is to place the permanent magnets (PMs) on the stator, aiming at only retaining iron on rotors to enhance its mechanical robustness, and the PMs located on the stator can be avoided falling off to further improve operational reliability. An axial-flux pattern is adopted so as to make that the stator can be easily fixed to the housing and the high- and low-speed rotor shafts can be conveniently led out from the axial side. Hence, compared with the existing coaxial rotor-excitation MGs, the proposed SEAMG has improved mechanical reliability and low processing difficulty. Its operation principle is explained and the general optimization design considerations are illustrated to achieve the expected torque transmission performance. A prototype is built and performance evaluation using the 3-D finite element analysis (FEA) and experiments is conducted to verify its validity.