| 摘要 |
PURPOSE:To prevent friction and abrasion from generating, by providing the first and the second shaft part and bearing part of a permanent magnet magnetized in a focus direction at both end parts of the second movable part in the focus direction, fitting them in the third and the fourth shaft part and bearing part having the like-poles as those of the above, and fixing either the third and the fourth bearing part or shaft part, at a base. CONSTITUTION:A cylindrical permanent magnetic 11 is magnetized in a focus direction F, and permanent magnet bearings 12a and 12b fixed on a base 10 facing the like-poles oppositely are arranged at both ends of the magnet. Therefore, the cylindrical permanent magnet 11 can be floated from the base part by mutual resiliency because the like-pole of the magnet faces with those of the permanent magnet bearings 12a and 12b. Also, by providing a fitting part between the permanent magnets, the permanent magnet 11, and the permanent magnet bearings 12a and 12b are held on a center shaft without bringing into contact with each other, by the resiliency generated mutually even in a diameter direction vertical to the shaft direction of a cylinder. In such a way, the friction or the abrasion generated at the bearing can be prevented from occurring, and the durability of the bearing part can be improved.
|
