| 摘要 |
PURPOSE:To obtain a motor whose cogging torque is suppressed to a low level by a method wherein the boundary surface of a pole in a field part is inclined to the axial direction. CONSTITUTION:A board 2 is fixed to the outer circumference of a bearing sleeve 1 which is attached to the stationary part of a brushless motor and a stator 3 is attached to the board 2 with a spacer 4 therebetween. The stator 3 is composed of a core 5 and coils 6. A rotary shaft 8 is vertically inserted into the bearing sleeve 1 and supported with bearings 7 therebetween. A rotor yoke 10 is attached to the top end of the rotary shaft 8 with a boss 9 therebetween. The outer circumferential part of the rotor yoke 10 is hung downward. A rotor magnet 12 is attached to the hanging part 10a. A rotor 11 is composed of the rotor yoke 10 and the rotor magnet 12. Salient poles 13 and slots 14 are formed in the core 5 and coils 6 are wound on the salient poles 13. Further, the boundary surface of a pole in a field part is inclined toward an axial direction. As a result, a cogging torque can be suppressed. |
