Analysis of coaxial magnetic gears

The behavior of a magnetic gear which employs rare earth magnets is analyzed; the magnetic gear allows the power to be transmitted by transforming speed and torque. An analytical simplified approach for the analysis of the considered magnetic gear is used in this paper. The approach can be suitable for design aims. The mathematical model is one-dimensional: only the variation of electromagnetic quantities as function of angular position is considered, the permanent magnets are modeled by means of constant currents located at their edges. The resulting magnetomotive force generated by two rotors is modulated by the distribution of the variable permeance due to the difference of the magnetic permeability between the air of the slots and the magnetic material of the pole-pieces. The analytical results are verified by means of a finite element method.