Submarine propeller shaft seal

Claim 1

A FLUID SEAL FOR PREVENTING FLOW OF A PRESSURIZED FLUID ALONG A SHAFT TO AN AREA OF LOWER PRESSURE, SAID SEAL COMPRISING, IN COMBINATION; AN ANNULAR SEALING ELEMENT CIRCUMFERENTIALLY ENGAGING THE SHAFT IN ROTATABLE RELATION SHIP AND EXPOSED TO THE PRESSURIZED FLUID ON ONE AXIAL FACE THEREOF, MEANS FOR SUPPLYING A FLOW OF HYDRAULIC FLUID TO THE OTHER AXIAL FACE OF SAID SEALING ELEMENT UNDER A REGULATED PRESSURE SUBSTANTIALLY EQUAL TO THAT OF THE PRESSURIZED FLUID, AND A SLEEVE SPACED CIRCUMFERENTIALLY ABOUT THE SHAFT AND FORMING AN ANNULAR PASSAGEWAY THEREBETWEEN, SAID PASSAGEWAY COMMUNICATING WITH SAID OTHER AXIAL FACE OF SAID SEALING ELEMENT AT ONE END THEREOF TO RECEIVE SAID FLOW OF HYDRAULIC FLUID, SAID PASSAGEWAY COMMUNICATING WITH THE AREA OF LOWER PRESSURE AT THE OTHER END THEREOF TO DELIVER SAID FLOW OF HYDRAULIC FLUID UNDER THE LOWER PRESSURE, SAID PASSAGEWAY TAPERING FROM A LARGER DIAMETER AT SAID ONE END THEREOF TO A SMALLER DIAMETER AT SAID OTHER END THEREOF, SAID TAPERED PASSAGEWAY COOPERATING WITH SAID FLOW OF HYDRAULIC FLUID THRETHROUGH TO SUPPORT SAID SLEEVE RADIALLY ABOUT THE SHAFT.