| 摘要 |
PROBLEM TO BE SOLVED: To capture gas evaporated from a magnetic fluid so as to prevent the evaporated gas from flowing into the low pressure side by providing a cooling means having a cooling face for liquefying gas to capture it, on the lower pressure side than a magnetic fluid seal part in an annular clearance. SOLUTION: A magnetic fluid seal part MS has a magnet 6 with unlike poles arranged in an axial direction, and magnetic pole members 7a, 7b serving as first magnetic pole parts brought into contact with both axial sides of the magnet 6 so as to be magnetic poles, and a space to the peripheral wall surface 2a of a rotary shaft 2 is sealed with a magnetic fluid ML interposed at a magnetic circuit MC where magnetic flux generated by the magnet 6 is formed. During operation of the sealing device 1, when a solvent of the magnetic fluid ML is evaporated as gas by heating generated in assocaition with the rotation of the rotary shaft 2 and pressure drop of each chamber and is going to flow into the lower pressure side L, this gas is liquefied at the cooling face 10b of an annular member 10 where cooling water A1 flows through and captured by the cooling face 10b so as to restrain the evaporated gas from flowing into the low pressure side L. |
