US Patent 7377518 Mechanical seal ring assembly with hydrodynamic pumping mechanism

A seal ring configuration adapted to be disposed about a shaft to seal a fluid at a pressure differentials across the seal. The seal ring configuration comprises a mating ring and an axially movable primary ring. The primary ring includes a seal face in opposing relationship to the mating ring seal face to define a seal interface. The mating ring seal face or the primary ring seal face defines an annular axially recessed section and a dam section. The recessed section is axially disposed further from the cooperating seal face relative to the dam section. The axially recessed section further includes a face pattern axially spaced further from the dam section than the recessed portion and is capable of generating a hydrodynamic force between the mating ring seal face and the primary ring seal face.