| 摘要 |
PURPOSE:To eliminate the use of an O-ring with the use of a magnetic seal, by constraining a magnetic fluid between one peripheral surface of magnetic pole pieces, for guiding the magnetic force of a permanent magnet, jointed at the other peripheral surface thereof with the outer peripheral surface of a rotary shaft, and the inner peripheral surface of a housing. CONSTITUTION:A permanent magnet 1 is arranged surrounding around the outer peripheral surface of a rotary shaft 1 which rotatably supported by bearings 2, 3, having its inner peripheral surface opposing the outer peripheral surface of the rotary shaft 1, and annular magnetic pole pieces 6, 7 abutting respectively against both magnetic pole ends of the permanent magnet 5 are welded to the inner peripheral surface of a housing 4. Magnetic fluids 7, 8 are constrained in a slight gap defined between the inner peripheral surfaces of the magnetic pole pieces 6, 7 and the outer peripheral surface of the shaft 1 by the magnetic force of the permanent magnet 5. Accordingly, a seal means having no O-ring may be obtained. |
