Unbalanced Magnetic Force Calculation for Rotor and Stator Assembly in Permanent Magnet Motor with Large Diameter

In this paper, formulas to calculate possible UMFs during assembly process are introduced in order to save calculation time and efforts without using a fully configured 3-dimensional (3-D) analysis model. To calculate the UMFs according to the degree of rotor eccentricity in every time that the rotor position is relatively changed to the stator position in axial direction, the proposed formulas are used with a fully configured 2-dimensional (2-D) model or 2-D and 3-D periodic analysis models. The reliance of the formulas is verified by comparing the results calculated by the formulas and showing the agreement. Then, assembly jigs are designed considering the calculated UMFs.