摘要
Magnetic harmonic gears with high gear ratios exhibit high torque densities.However,the revolution and rotation of the eccentric rotor makes the magnetic field analysis complex.In this study,an analytical model of magnetic fields for magnetic harmonic gears is developed by using the fractional linear transformation method.The transformation formula is accurate in theory and suitable for the analysis of magnetic fields with large eccentricity.The rotor eccentricity region in the z-plane is mapped onto a uniform region in the w-plane.The magnetic field solutions are obtained by modulating the magnetic field distributions without rotor eccentricity with the relative permeance function derived from the effect of rotor eccentricity.The torque of magnetic harmonic gears is calculated from the radial and tangential components of the air-gap magnetic fields.Results of the finite element method and prototype test confirm the validity of the analytical prediction.
