Study of a high efficiency and low cogging torque spindle motor

A high efficiency and low cogging torque spindle motor has been designed by varying the magnetization profiles of the rotor and the geometry shape of the teeth of the stator in motor. Both radial and fixed magnetization profiles for the magnetic ring in a spindle motor were studied by computer simulation and experimental measurement. After smoothing the edge of the teeth of the stator, we can reduce the cogging torque tremendously. Experimental data are in good consistent with theoretical calculation.