| 摘要 |
PROBLEM TO BE SOLVED: To reduce the thickness while the performance is improved, by utilizing a stator in which improvernent is made for the shape of circuit board for connection of coil. SOLUTION: A rotor 24 designated on a bearing 23 to freely rotate has a disc type magnet 27 magnetized in multiple poles. A circuit board 32 of stator 31 is a ring type circuit board having the internal diameter larger than the external diameter of a back yoke 30. Moreover, the stator 31 is allocated axially opposed to the back yoke 30 and the back yoke 30 is provided within the hollow area at the internal side of the ring type circuit board 32 so that it is allocated adjacent to the coil. |
