Abstract: An actuator for controlling an air damper includes a motor, an output connector for connecting the actuator to the air damper, a transmission mechanism connecting the motor to the output connector, and an energy storage device that drives the output connector to close the air damper when power to the motor is cut off. The motor has a stator and a rotor. The stator has a stator core including a yoke and nine poles extending from the yoke. The rotor has a shaft and an annular permanent magnet. The magnet forms twelve poles with alternate N and S polarities. An inclination angle of boundaries between adjacent poles of the magnet relative to an axis of the motor is in the range of 13 to 17 degrees.

Abstract: A universal motor has a stator and a rotor installed in the stator. The stator comprises a pair of stator segments. Each segment has a yoke with first and second ends, a pole and a neck connecting the pole to the first end of the yoke. The second end of each yoke is connected with the first end of the other yoke. A pair of pre-formed windings are mounted on respective poles of the stator segments.

Abstract: A universal motor has a stator and a rotor installed in the stator. The stator comprises a pair of stator segments. Each segment has a yoke with first and second ends, a pole and a neck connecting the pole to the first end of the yoke. The second end of each yoke is connected with the first end of the other yoke. A pair of pre-formed windings are mounted on respective poles of the stator segments.