Seals for use between two relatively-rotating surfaces

Claim 1

A seal for retaining liquid between two relatively rotatable members irrespective of the direction of rotation, of which one member has a seal housing and the other member has a surface transverse to the rotational axis to be engaged by the seal, comprising a sealing ring having a static sealing portion mounted in the seal housing, a flexible flange extending from the static sealing portion, generally in the direction in which the said transverse surface extends and towards the liquid to be sealed, to an outer end portion of the sealing ring, two mutually inclined surfaces on said outer end portion defining a circular sealing lip, and a plurality of circumferentially spaced projections raised on that inclined surface which is the closer of the two inclined surfaces to the static sealing portion and which is remote from the liquid, each projection having a surface which is generated by movement, about the central axis of the ring, of a line which is substantially perpendicular to the said central axis and which at one position is contiguous with the sealing lip and which, on opposite sides of said one position recedes from the sealing lip, the sealing lip and the portion of the said surface of each projection which is contiguous with the sealing lip engaging the said transverse surface with an interference fit, whereby upon assembly of the sealing ring between said members, the flange is deflected from its free state, about the static portion, the part of the surface of each projection in the vicinity of that part which is contiguous with the lip consequently engaging the said transverse surface over an area having opposite sides which extend away from the sealing lip and which diverge away from each other and with a pressure which increases as the distance from the sealing lip in a direction at right angles to the plane of the sealing lip increases.