Overhang effect analysis of brushless DC motor by 3-D equivalent magnetic circuit network method

This paper investigates the permanent magnet overhang effect in brushless dc motor. The characteristics are analyzed according to the variation of symmetric overhang length and asymmetric overhang ratio. A three-dimensional equivalent magnetic circuit network (EMCN) method is used for the accurate and efficient analysis. From the results, it is quantitatively verified that the increase of overhang length enhances the linkage fluxes of the stator and the asymmetric overhang ratio has a large effect on the axial magnetic force.