| 摘要 |
PROBLEM TO BE SOLVED: To provide a sealing device in which leakage prevention effects of a sealed fluid which is sealed in an internal environment can be improved by maintaining sealability in the internal environment with respect to an external environment constant at all the time with pumping effects by a spiral protruding part, and preventing dust from being meshed to the spiral protruding part.SOLUTION: On an external side slope 8 of a seal lip 2, a recessed area 8g is constituted which is recessed rather than other portions over a middle T from a lip distal end 2t to the external environment, and a plurality of spiral protruding parts 4 are constituted which form a contour raised by crossing the recessed area from the lip distal end. A ridge line 4r of each spiral protruding part is inclined linearly at a fixed angle &thetas; with respect to a peripheral surface 6s of another member 6 with which the lip distal end is brought into contact. In each ridge line, a point is specified which is separated from the lip distal end to the external environment just by a distance A. When a gap between the point and the peripheral surface of the other member is defined as B, the relations of A=0.5 mm and B≥50 μm are satisfied. |
