| 摘要 |
PURPOSE:To prevent a reduction of the sealing effect due to a reduction of magnetic fluid caused by its leakage by containing the magnetic fluid between a cylindrical part and a shat in a magnetic fluid seal apparatus. CONSTITUTION:A cylindrical part 18a is extended in between a flange 18b, a magnetic shaft 11 and a yoke 13 to a side which is connected to a vacuum device, and after the cylindrical part 18a and flange 18b are integrally assembled, the housing of non-magnetic material is attached to the shaft 11. A gap (g) is provided between the cylindrical part 18a and shaft 11. By exerting a magnetic force from the outside of the cylindrical part 18a to the shaft 11 by a magnet 12 and the yoke 13, the magnetic fluid 14 is contained in the gap (g) formed between the cylindrical part 18a and shaft 11 so that a shaft sealing effect may be provided in that the magnetic containment is conducted in a position corresponding to the yoke 13. In this arrangement, there is no leakage between the magnet 2 and yoke 3, and the housing 5 and magnet 2 and yoke 3, and moreover, the temperature fluctuation will not adversely affect. |
