| 摘要 |
PURPOSE:To possess a stable earth function and restrain friction and noise by surroundingly providing a retainer whose composite material is of small electric resistance and of self-lubrication, along yoke members on the outside of a closed magnetic circuit, and retaining turnably a plurality of balls of electric conduction material by means of the retainer. CONSTITUTION:A plurality electric conductive balls 6 are retained in such a way that they keep contact with both of yokes 2, 3 and a rotational shaft 4, by means of a retainer 7 whose material is of small electric resistance and of self lubrication, surroundingly provided along the outside of a closed magnetic passage. As a result, magnetic fluids 5 are retained by means of leaked magnetic fields between yokes 2, 3 at the closed magnetic passage constituted among a permanent magnet 1, yokes 2, 3 and the rotational shaft 4, and the rotational shaft 4, and a seal is formed and at the same time, a fully stable earth function can be made to be retained between yokes 2, 3 and the rotational shaft 4 through balls 6. Also, as sufficient lubrication and an anti-wear quality can be imparted, the occurrence of noise can be reduced. |
