38 / 2022-06-20 16:31:34

A Novel Eccentric Harmonic Magnetic Gear with an Inhomogeneous Structure and Halbach Array

Air gap magnetic field; Eccentric harmonic magnetic gear; Halbach array magnetization; Electromagnetic torque

Electric Machine Design and Control > Electric machine designs

Compared with the conventional coaxial magnetic gear (CMG), the eccentric harmonic magnetic gear (EHMG) has a higher transmission ratio. In order to obtain a higher torque density with a large transmission ratio, a novel EHMG with an inhomogeneous structure and Halbach array is proposed in this paper. According to the magnetic field modulation theory and the unilateral effect of the Halbach array, a fan-shaped structure is applied to the permanent magnets (PMs) on the inner rotor, and the PMs on the outer stator are unevenly divided according to the ratio of 1:n:1. In addition, both the inner rotor and the outer stator PMs are magnetized by the Halbach array. A finite element model of an EHMG with 15 pole pairs on the inner rotor PMs and 16 pole pairs on the outer stator PMs is established, and the air-gap magnetic field and torque of the EHMG are calculated. Compared with the conventional EHMG, the torque of the proposed EHMG is increased from 38.04N·m to 50.41N·m, which verifies that the model is an effective attempt to improve the torque density of EHMG.