Construction of Radial Flux Cycloidal Magnetic Gears with Reduced Permanent Magnet Piece Count Using Consequent Poles

Cycloidal magnetic gears provide a noncontact alternative to mechanical gears for high gear ratio applications. Most cycloidal magnetic gears in the literature have magnets on the surface of each rotor. However, on a consequent pole rotor, all the magnets are magnetized in the same direction and separated by ferromagnetic teeth. This potentially provides magnet retention and assembly advantages. The consequent pole rotors can take advantage of wider magnets and thinner magnetic air gaps, due to the potential elimination of the magnet retention sleeve. This paper studies the fabrication process and performance of the first cycloidal magnetic gear with a consequent pole rotor. The prototype was built, and its experimentally measured slip torque achieved a 95% match with the 3D FEA simulation model values. The measured ratio of the shafts speeds showed excellent agreement with the ideal 20:1 gear ratio.