A Novel 3-D Mathematical Modeling Method on the Magnetic Field in Nutation Magnetic Gear

Accurate prediction of the magnetic field is an essential guideline for permanent magnetic gear design and optimization. The existing magnetic field calculation methods are divided into 2-D and 3-D calculation methods. For coaxial magnetic gears, the calculation of a 2-D magnetic field can be employed to meet the design requirements. However, as a new spatial transmission mechanism, nutation magnetic gear relies on a 3-D magnetic field to transmit force and torque. Therefore, the 2-D magnetic field cannot meet the design requirements. Hence, it is necessary to accurately predict the 3-D magnetic field. In this article, an analytical mathematical model of the 3-D magnetic field of magnetic gears is established. To verify the accuracy of the model, the magnetic field generated by the same magnetic gear is predicted by the proposed model, finite element method, and equivalent current method. The results indicate that the 3-D magnetic field mathematical model proposed in this article can accurately predict a 3-D magnetic field, which is an essential guide for the research and optimization of magnetic gears.