Calculation of Torque and Loss of Coaxial Magnetic Gear with Halbach Array in 3D Model

In two-dimensional field, the end effect exists in the calculation of the electromagnetic characteristics of the magnetic gear, which leads to the inaccurate calculation of the air-gap magnetic field and torque. In order to improve the calculation accuracy of the electromagnetic characteristics of the magnetic gear, a 3D coaxial magnetic gear (CMG) with Halbach arrays distribution is proposed in this paper. Using the unilateral effect of the Halbach arrays, the magnetic field on the air gap side is strengthened, and the magnetic field on the iron yoke side is weakened. The topology of CMG with 4 inner and 17 outer poles is established and compared with the 2D model with the same parameters. The results show that the 3D CMG with Halbach array distribution can effectively reduce the torque ripple, and the accuracy of torque and loss calculation is improved compared with 2D model. The analysis results can provide a basis for the design and manufacture of magnetic gear.