| 主权项 |
1. A rotary sealing assembly, comprising:
first and second machine components defining an annular groove comprising a first surface, a structural surface, and at least one radially inward facing peripheral surface, said first surface facing said structural surface of said annular groove; a relatively rotatable member defining a relatively rotatable external surface of generally cylindrical form located at least partially within said second machine component and separated from said second machine component by an extrusion gap; a rotary seal at least partially received in said annular groove, said rotary seal maintained in direct compression between said at least one radially inward facing peripheral surface of said annular groove and said relatively rotatable external surface, said rotary seal having a dynamic sealing lip located between said first surface and said structural surface of said annular groove, said dynamic sealing lip having a radially inwardly facing dynamic sealing surface in sealing contact with said relatively rotatable external surface, said dynamic sealing surface located radially inwardly of and encircled by said at least one radially inward facing peripheral surface of said annular groove; a pressurized fluid located between said first machine component and said relatively rotatable external surface and retained by said rotary seal; a backup ring located at least partially within said annular groove and located between said rotary seal and said extrusion gap and interposed between said first surface and said structural surface of said annular groove, said backup ring having generally oppositely facing first and second end surfaces and an outwardly facing outer surface radially spaced from, and free from direct contact with, said radially inward facing peripheral surface, at least a portion of said first end surface contacting and axially supporting at least a portion of said rotary seal and at least a portion of said second end surface facing said extrusion gap; said relatively rotatable external surface rotating relative to said rotary seal, said backup ring, and said first and second machine components; and said backup ring constructed at least in part from metal, and having a dynamic surface facing radially inward toward said relatively rotatable external surface and establishing at least one region of clearance between said dynamic surface and said relatively rotatable external surface extending from said first end surface to said second end surface and exposed to a lubricant, at least a portion of said region of clearance gradually diminishing in a circumferential direction providing gradual circumferential convergence between said ring dynamic surface and said relatively rotatable external surface, and forming a hydrodynamic inlet adapted for hydrodynamically wedging a portion of said lubricant between said ring dynamic surface and said relatively rotatable external surface in response to said relative rotation between said ring dynamic surface and said relatively rotatable external surface, wherein said ring dynamic surface is penetrated by at least one lubricant passage hole located between and axially spaced from said first and second end surfaces of said backup ring and defining first and second open ends, said first open end facing radially inward and said second open end facing radially outward and located radially outward of said first open end. |
