Hydrodynamic lift-type face seal

Claim 1

A hydrodynamic lift-type face seal comprising: an annular shoulder member adapted to be secured to a rotatable shaft for rotation therewith, said annular shoulder having a radially extending annular planar sealing surface, an annular housing member adapted to have said rotatable shaft extend therethrough, a seal ring assembly positioned within said housing in nonrotatable relation thereto, an annular seal ring mounted in said seal ring assembly and having radially extending annular planar sealing surface, means to urge said last named planar sealing surface into abutting sealing relation with said first named planar sealing surface, one of said sealing surfaces having a plurality of separate recessed pockets formed therein, said pockets arranged in spaced relation to each other and along substantially the same circular path, certain of said recessed pockets having a first relatively deep recessed portion and a second relatively shallow recessed portion contiguous with said first relatively deep recessed portion and forming a step therebetween, said step having a radially extending chamfered edge portion, said recessed pockets arranged to permit the flow of fluid therefrom between said sealing surfaces to thereby urge said sealing surfaces away from each other; a first annular fluid distribution groove in said other sealing surface, said other sealing surface positioned in overlying relation with portions of said pockets for flow of fluid into said annular distribution groove; and a second annular vent groove in said other sealing surface spaced radially outwardly from said first annular fluid distribution groove forming a planar annular surface therebetween, said planar annular surface forming a seal dam for the fluid introduced into said distribution groove and providing a seal between said planar sealing surfaces.