Simulation study of the reduction of cogging torque in permanent magnet motors

The reduction of cogging torque in permanent magnet motors has been studied by varying the geometry shape of the saliencies of the armature core on stator of a 12-pole 9-tooth spindle motor. Mechanism of this reduction is explained by the minimum net integral of the product of normal and tangential magnetic flux with respect to the mechanical angle between the stator and rotor.