Abstract: A sealing assembly for achieving a fluid seal between a rotatable shaft and a housing circumscribing the rotatable shaft to inhibit fluid leakage therebetween a high pressure fluid region and a relatively lower pressure fluid region. The sealing assembly includes at least one primary seal, comprising an axial stack of a plurality of diaphragm members, including an upstream diaphragm and a downstream diaphragm. A plurality of finger seal plates are positioned between the upstream diaphragm and the downstream diaphragm. The plurality of diaphragm members define a passageway in fluid communication with the high pressure fluid region and a low pressure fluid region. The sealing assembly includes at least one secondary seal positioned within the passageway and configured to convert fluid from a high pressure axial pressure balance to a low pressure axial pressure balance thereby reducing a radially inward pressure load.

Abstract: A shaft oil purge system comprises an entrance seal, an exit seal and a buffer air flow. The entrance seal comprises a circumferential carbon seal running on an inner shaft and another carbon seal running on an outer shaft. The exit seal comprises a labyrinth seal positioned on the inner shaft and towards the exit end of the annulus between the shafts. An abradable material filled groove positioned radially outward from the exit seal allows the inner shaft to rub without compromising the integrity of the outer shaft. The buffer air flow enters the annulus from a cavity at the entrance seal, purges oil from the annulus and improves the efficiency of the seals.

Abstract: A system includes a case, a stator, a ring seal, and a rotor and is configured to pump air out of a housing. The case is mounted on the housing. The stator is mounted within the case and has two sides, an inner diameter and an outer diameter, where the first side faces the case. The ring seal is disposed between the stator first side and the case. The rotor is mounted on a shaft and has a side facing the stator first side. The rotor side has grooves, an inner and outer peripheral surfaces, and is configured to pump air from the outer peripheral surface to the inner peripheral surface to thereby pump air out of the housing. The stator inner diameter is configured and the ring seal is positioned such that separation forces are substantially equal to or less than closing forces during a system breach.