Abstract: The present invention relates to a pole piece structure of stator with radial winding, which employs an optimum ratio ? to define the form of the pole piece, increase the overlap region of inductance and torque and lower the cogging torque of a motor, so as to strengthen the self-starting capability of the motor and minimize torque ripple to enhance the overall performance of the motor. The pole piece structure includes a hub having a hole at the center, and a plurality of poles integrally formed on the periphery of the hub, extended to radiate in a radial direction, and having a pole shoe expanded from an end of each pole in a tangential direction, wherein the angle of a single pole shoe is divided by a pitch angle of two adjacent poles to obtain a ratio in a range of 0.86˜0.95.

Abstract: The present invention relates to a pole piece structure of stator with radial winding, which employs an optimum ratio ? to define the form of the pole piece, increase the overlap region of inductance and torque and lower the cogging torque of a motor, so as to strengthen the self-starting capability of the motor and minimize torque ripple to enhance the overall performance of the motor. The pole piece structure includes a hub having a hole at the center, and a plurality of poles integrally formed on the periphery of the hub, extended to radiate in a radial direction, and having a pole shoe expanded from an end of each pole in a tangential direction, wherein the angle of a single pole shoe is divided by a pitch angle of two adjacent poles to obtain a ratio in a range of 0.86˜0.95.