| 摘要 |
PROBLEM TO BE SOLVED: To suppress the lowering of a screw pump action in a forward direction caused by wear, and to effectively prevent leakage caused by a screw pump action in a reverse direction, in a sealing device which is arranged at a seal lip so that screw projections become alternately reverse with respect to each other in a circumferential direction.SOLUTION: A first screw projection 24 which is inclined from a lip edge 21 in a constant direction with respect to a circumferential direction, and substantially constant in a projection height, and a second screw projection 25 which is inclined from the lip edge 21 to a direction reverse to the first screw projection 24, and substantially constant in a projection height are formed at an anti-sealing side conical face 23 which becomes large in diameter as progressing toward an anti-sealing space B from the lip edge 21, a third projection 26 which is inclined to a direction reverse to the first screw projection 24, and becomes high in a projection height toward a side opposite to the lip edge 21 is formed at a relative anti-sealing space B side rather than the first screw projection 24, and a fourth screw projection 27 which is inclined to a direction reverse to the second screw projection 24, and becomes high in a projection height toward a side opposite to the lip edge 21 is formed at the relative anti-sealing space B side rather than the second screw projection 24.SELECTED DRAWING: Figure 1 |
