Patent ID: 7938402

Claim:
An air-riding seal system comprising: (a) a primary seal assembly movable between a seal runner extending from a rotatable shaft and a housing structure, the primary seal assembly including: (i) an annular seal ring having a cross section that is substantially L-shaped and a surface with a step face and a circumferential dam, the surface disposed opposite of a sealing surface along the seal runner; and (ii) an arcuate support arm attached at one end to the annular seal ring and having a tooth at one end adjacent to an outermost circumferential surface separated by a gap; (b) a secondary seal ring disposed between and contacting said primary seal assembly and said housing structure so as to form a bore seal and a face seal therewith; (c) a structure along said surface which increases the stiffness of a thin film between said surface and said sealing surface, said structure having a plurality of radial dams and at least one hydrodynamic pocket disposed along said surface in an outward radial arrangement with respect to said circumferential dam; and (d) said outermost circumferential surface along said seal runner has a notch that varies said gap depending on the relative position between said primary seal assembly and said seal runner.