| 摘要 |
PURPOSE:To enhance the sealing performance by forming a concentrical flange on the way of a rotary shaft, installing magnetic poles to the two mating surfaces with housing enwrapping the flange through a gap, providing grooves concentrical to the shaft, and thereby encapsulating a magnetic fluid. CONSTITUTION:A concentrical flange 4 is formed on the way of a rotary shaft 2 penetrating from the atmospheric pressure side A to the gas pressure side G, and in this flange 4 a plurality of grooves 3 concentrical to this rotary shaft 2 are formed. With a minute gap to the flange 4 magnetic poles 14, 15 are installed to housing 5, 6 enwrapping the flange 4 through a gap, and a magnet 19 is mounted to the flange 4 periphery between these poles 14, 15. A magnetic fluid 18 is encapsulated in the gaps h1, h2 between the two poles 14, 15 and the flange 4. Accordingly the magnetic fluid 18 has flux concentration at the protrusion between the grooves 3, which ensures high sealing performance. This sealing performance will be retained high even after a long time leaving. |
