Analytical model of non-contact magnetic transmission

This paper proposes a method to analyze and calculate the magnetic field distribution and electromagnetic torque of a coaxial magnetic gear (CMG). The analytical approach is based on solving the Laplace and Poisson equations for each subdomain (permanent magnet and air gap). The analytical formula of electromagnetic torque of CMG is obtained by using boundary conditions and continuity conditions. This paper organizes the equation group, transforms the coefficient matrix from an $8 \times 8$ sparse matrix into a diagonal matrix, and simplifies it into a $4 \times 4$ matrix, which greatly reduces the difficulty of calculation. Compared with the finite element model, the accuracy of the multivariable analytical expression reaches more than $\mathbf{9 5 \%}$ and the calculation time is much shorter. This greatly improves the efficiency of CMG’s early optimization work.