| 摘要 |
PURPOSE:To obtain strong magnetic flux density and to prevent th demagnetization of a segment magnet by forming at least part of the segment magnet of a material having high residual magnetic flux density and forming the other of a material having a high coercive force. CONSTITUTION:A segment magnet is formed of at least two types of ferrite materials 1, 2. The ferrite materials 2 has a high residual magnetic flux density, and the ferrite material 1 has high coercive force. A boundary 3 between the material 1 and the material 2 is set not to be prependicular to the projection to the surface of side face of the magnet in the rotating direction of the rotor. |
