Magnetic-Field Computation of a Novel 3-DOF Deflection-Type PM Motor with Analytical and Finite-Element Methods

Based on brief introduction of the operation principle and superior performance of the permanent-magnet (PM) deflection type three-degrees-of-freedom motors, one novel PM motor air-gap magnetic-field calculation schemes based on the analytical and finite-element methods are presented and scalar magnetic-flux density calculation formulae in the spherical coordinate are developed. A rotor magnetic-field model is built in a 3D finite-element software and computed with simulation to derive the flux-density distribution under different magnetization modes. The results obtained with these two methods are compared and validated. The theoretical analysis and computation results demonstrate the effectiveness of the designed structure; it is easy for the rotor to achieve a three-degree-of-freedom deflection motion, which provides references for further research and experimental design of the related motors or actuators.