Air Riding Seal

An air-riding seal system comprising:

• (a) a cylindrical-shaped carrier disposed about a rotatable shaft with a seal runner extending therefrom;
• (b) a primary seal assembly including at least two segments which form a ring-shaped seal, each said arcuate seal segment contacts said cylindrical-shaped carrier and is movable thereon, each said arcuate seal segment having a cross section that is substantially L-shaped and a surface with a step face and an arcuate dam, said surface disposed opposite of a sealing surface along said seal runner, each said arcuate seal segment having an arcuate support arm disposed at one end thereof and having a tooth disposed at another end adjacent to an outermost circumferential surface along said seal runner, each said tooth and said outermost circumferential surface separated by a gap;
• (c) a secondary seal ring disposed between and contacting each said primary seal assembly and a housing structure so as to form a bore seal and a face seal therewith;
• and
• (d) a structure along each said surface of each said primary seal assembly which increases stiffness of a thin film between each said surface and said sealing surface, said structure having at least two radial dams or at least one hydrodynamic pocket disposed along said surface in an outward radial arrangement with respect to said arcuate dam, said outer outermost circumferential surface along said seal runner has a notch that varies each said gap depending on relative position between said arcuate seal segment and said seal runner.

An air-riding seal system comprising:

• (a) a seal assembly movable between a seal runner extending from a rotatable shaft and a housing structure, said 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, said surface disposed opposite of a sealing surface along said seal runner;
• and
• (ii) an arcuate support arm attached at one end to said annular seal ring and having a tooth at one end adjacent to an outermost circumferential surface separated by a gap;
• and
• (b) a structure along said surface which increases stiffness of a thin film between said surface and said sealing surface, said structure having a plurality of radial dams or at least one hydrodynamic pocket disposed along said surface in an outward radial arrangement with respect to said circumferential dam, said outermost circumferential surface along said seal runner has a notch that varies said gap depending on relative position between said seal assembly and said seal runner.

An air-riding seal system comprising:

• (a) a cylindrical-shaped carrier disposed about a rotatable shaft with a seal runner extending therefrom;
• (b) a seal assembly including at least two segments which form a ring-shaped seal, each said arcuate seal segment contacts said cylindrical-shaped carrier and is movable thereon, each said arcuate seal segment having a cross section that is substantially L-shaped and a surface with a step face and an arcuate dam, said surface disposed opposite of a sealing surface along said seal runner, each said arcuate seal segment has an arcuate support arm disposed at one end thereof and has a tooth disposed at another end adjacent to an outermost circumferential surface along said seal runner, each said tooth and said outermost circumferential surface separated by a gap;
• and
• (c) a structure along each said surface of each said seal assembly which increases stiffness of a thin film between each said surface and said sealing surface, said structure having at least two radial dams or at least one hydrodynamic pocket disposed along said surface in an outward radial arrangement with respect to said arcuate dam, said outer outermost circumferential surface along said seal runner has a notch that varies each said gap depending on relative position between said arcuate seal segment and said seal runner.