| 摘要 |
PROBLEM TO BE SOLVED: To maintain the excellent sealing performance for a long time by forming a tip of a seal lip with an annular flat surface for tightly fitting to a mating member freely to be slid, and providing the flat surface with a pumping screw. SOLUTION: A tip (inner peripheral edge) of a seal lip 1 is provided with an annular sealed fluid side inclined surface 2, of which diameter dimension is gradually enlarged toward the sealed fluid side A, and an annular atmospheric air side inclined plate (opposite sealed fluid side inclined surface) 3, of which diameter dimension is gradually enlarged toward the atmospheric air side (opposite sealed fluid side) B. An annular flat surface 4, which tightly contacts with the outer peripheral surface of a shaft 21 as a mating member with the predetermined axial width (w) freely to be slid thereon, is provided between the inclined surfaces 2, 3. Further, the flat surface 4 is provided with an angle, projecting or groove-like slit-like screw (parallel screw) 6 for pushing back the sealed fluid to the sealed fluid side A with the pumping work, and the screw 6 is formed into the angle shape or the projecting shape. |
