| 摘要 |
PROBLEM TO BE SOLVED: To reduce vibrations and noise by magnetically attracting a rotating body to a fixing part in the thrust direction by a magnetic attraction device provided in the rotating body and the fixing part. SOLUTION: The magnetic centers of a driving field magnet 13 and a yoke 4 are made to accord with each other, and an attracting magnet 18a is fixed to an open end located on the base 2 side of a sleeve near to the rotation center of the driving field magnet 13, and on the other hand, an attracting magnet 18b with the magnetic pole of a single pole for attracting each other in opposite to the attracting magnet 18a being magnetized is buried in an annular recessed part formed on the base 2. A rotor (hub assembly) is attracted on the base 2 side by the attraction of the attracting magnet 18a and the attracting magnet 18b without using the self-attracting action of the driving field magnet 13. Also, since the force of action in the thrust direction is located in the position near to the rotation center, a moment for moving the hub assembly vertically is reduced, thereby being able to reduce vibrations and noise. |
