| 摘要 |
PURPOSE:To reduce leakage flux tending to produce torque in the negative direction by securing permanent magnets subtending substantially the same angle as S pole magnets to the bottom of a rotor. CONSTITUTION:A magnetic flux generating means for forming a non-symmetric flux distribution in the same direction over an electric angle region above 180 degrees and two phase coils toroidally wound on a ring-like core are provided, and sector- shaped permanent magnets 10a and 10b subtending substantially the same angle as S pole magnets 3a and 3b are secured to the bottom 1a of a cup- shaped rotor 1. Thus, the magnetic flux produced from N pole magnets 2a and 2b passes through a stator yoke 6 to be forcused on the semi-cylindrical S pole magnets 3a and 3b provided on the side surface of the rotor 1 while it is also focused on the sector-shaped S pole magnets 10a and 10b. Thus, it is possible to relatively reduce leakage flux tending to produce torque in the negative direction and increase in effect the flux produced from the N pole magnets and tending to produce torque in the positive direction. |
