| 摘要 |
PURPOSE:To restart a rotor easily by distributing the magnetic field of a rotor magnet so that the electrical center of magnetic poles at a time when a coil for a stator is excited is displaced from the mechanical center of each magnetic pole for the rotor magnet. CONSTITUTION:A coil 5 corresponding to two phases is wound, forming slots 3a-3d and tees 4a-4d, thus shaping a stator 2 with four poles. The inside of a rotor magnet 1 mounted to the outer circumference of the stator 2 is mag netized alternately at N poles and S poles at every 90 deg.. The inside of the rotor magnet 1 is magnetized in such a manner that the intensity of a magnetic field in the radial direction of each magnetic pole is altered along the circumfer ential direction while positions where the intensity of magnetic fields in the radial direction of respective magnetic pole is maximized are displaced only by predetermined dimensions in the circumferential direction from the mechani cal center of magnetic poles. That is, lines X tying the positions A of the maxi mum magnetic fields of the opposite magnetic poles are displaced only by angles thetain the circumferential direction from the mechanical center lines Y of the magnetic poles. Accordingly, even when the rotor magnet 1 is stopped anywhere, self-start is enabled, thus resulting in smooth revolution. |
