Design and analysis of a new magnetic gear with multiple gear ratios

This paper proposes a new magnetic variable gear which offers different speed ratios. In order to provide the gear-ratio-changing ability, a high-remanence low-coercivity permanent magnet (PM), namely the aluminum-nickel-cobalt (Alnico), is utilized. By incorporating the concept of the magnetic gear and the concept of memory machine, a new double-deck structure of the stationary ring is developed to locate the magnetizing winding which can dynamically magnetize or demagnetize the Alnico PM. By using finite element analysis, the electromagnetic performance of the proposed magnetic gear at different gear ratios is analyzed. Hence, the corresponding validity can be verified.