| 摘要 |
PURPOSE:To eliminate cogging torque and to reduce the size and the cost by setting the surface area of the pole face of a field magnet larger than half that of a field core opposing to an armature core. CONSTITUTION:P field magnets 2 and P field cores 6 holding the field magnet in between constitute P pole of field on the circumference of a rotor shaft 1 and an armature core 3 is disposed through a predetermined gap. The armature core 3 has cylindrical shape provided with no tooth section and three-phase windings U1-U8, V1-V8, W1-W8 are arranged in the prescribed air gap and secured to the armature core 3. Since the armature core 3 has no tooth section, it provides no magnetic periodicity. Flux generated from the field magnet 2 flows into or flows out from the armature core 3 through a field core 6 and interlinks with winding groups of U, V, W phases. Since the surface area of the pole face of the field magnet 2 is set larger than half that of the field core 6 opposing the armature core, flux generated from the field magnet concentrates at the field pole thus providing high flux density. |
