PURPOSE: To work out to make the torque higher and to make it possible to manufacture at a low cost by drawing a part of the disc stator yoke and by forming the core to wind around with the winding coil integrated with the disc stator yoke.

CONSTITUTION: A winding coil 1 is wound around a core 2. The core 2 is drawn from a part of a stator yoke 3 and constituted. A winding coil 1 wound around the core 2 is fixed to the position of the stator yoke 3. A rotor magnet 5 adheres to inside a rotor yoke 4. The rotor yoke 4 is fixed to a shaft 8, which is forcibly inserted into a bearing 7 secured in a housing 6. The bearing 7 is secured to the housing 6 with the stator yoke 3 and a spacer 16 between.