| 摘要 |
PURPOSE:To provide a magnetic fluid shaft sealing device formed in such a way as to prevent a magnetic fluid from being splashed into a vacuum chamber. CONSTITUTION:Around a rotary shaft 2 disposed between a vacuum chamber V and atmospheric air A, plural yokes 4 are disposed at spaces apart along the axial direction of the rotary shaft 2. A magnetic fluid film 5 is formed between each yoke 4 and the rotary shaft 2 by magnetic force, and the rotary shaft 2 is sealed in the state of partial pressure chambers 6 being formed between the respectively adjacent fluid films 5. In this case, a communicating passage 7 for allowing the flow of air but impeding the flow of a magnetic fluid is provided between the vacuum chamber 6 and the partial pressure chamber 6a closest to the vacuum chamber V. |
