Analysis of magnetic field and levitation force characteristics for 3-DOF deflection type PM motors

The mechanism and characteristics of the electromagnetic radial force are important for motors with complicated structures. The three-dimensional analytical model of the air gap between the rotor and stator is established under rotor eccentricity conditions. Then, aiming at solving the unbalanced radial force problem with rotor static eccentricity, the air-gap flux density, radial electromagnetic force, and the comparisons of harmonic contents are calculated and presented based on FEA (Finite Element Analysis) and MATLAB simulation. Finally, the magnetic field model has been validated by experiments utilizing a prototype system. The results provide a theoretical guide for configuration design, optimization, and levitation control research on three degree of freedom deflection type motors.