Design and performance analysis of an improved double-flux-concentrating coaxial magnetic gear

Abstract

Magnetic gear has the advantages of less noise and vibration in non-contact driving and has a broad application prospect. To improve the magnetic gear’s torque performance, an improved double-flux-concentrating coaxial magnetic gear (DFC-CMG) is proposed in this paper. The DFC-CMG adopts arc-shape inner permanent magnets (PMs) and spoke-type outer PMs, which are embedded in the rotor iron yoke and tangentially magnetized along the circumference. In addition, to reduce the amount of iron, the outer rotor yoke periphery of the proposed model is slotted. The finite element method (FEM) is used to simulate conventional and improved models, respectively. The air gap magnetic field and electromagnetic torque of the conventional model and the improved model are calculated, and the harmonic content of the inner and outer air gap magnetic density is analyzed. Simulation results show that the torque density of the improved model is 34.6% higher than that of the conventional model, and the output torque ripple of the outer rotor of the improved model is reduced by 0.58% compared to the conventional model. This paper can provide some references for high-performance magnetic gears.