Patent ID: 7506875

Claim:
A sealing device for tightly sealing an annular space between two members combined with each other in such a way as to rotate relatively to each other and having a seal lip sliding on a peripheral surface of one member of the two members, the sealing device comprising: a sliding surface along the peripheral surface; an atmosphere side slope surface sloping to gradually enlarge a space with respect to the peripheral surface from an atmosphere side end edge of the sliding surface; first screw projections formed on the atmosphere side slope surface and the sliding surface, the first screw projections extending from the atmosphere side slope surface to a middle of the sliding surface; and second screw projections formed on the sliding surface, an end on a sliding surface side of the first screw projections being formed on the sliding surface, and a first portion on a slope surface side of the first screw projections having a shape in which a height increases toward an atmosphere side with a width kept at a nearly equal width, the first portion of the first screw projections having a cross section of a nearly pentagonal shape formed of parallel extending side walls terminating at a triangular shaped apex.