Aspirating face seal assembly for a rotary machine
An aspirating face seal assembly includes a stationary component and a seal body defining a seal face. The seal body defines a fluid feed passage within the seal body. The fluid feed passage includes an inlet, and one or more feed ports defined along the seal face. The seal body is moveably coupled to the stationary component via a resilient member. A first-pressure plenum is defined radially outward from the seal body and a second-pressure plenum is defined radially inward from the seal body. The seal assembly further includes a plenum seal forming a seal between a portion of the seal body and the stationary component and at least partially defining a third-pressure plenum in fluid communication with a high-pressure fluid source and with the inlet of the fluid feed passage. The third-pressure plenum is pressurized at a higher pressure than both the first-pressure plenum and the second-pressure plenum.
1 . An aspirating face seal assembly, comprising:
a rotating component defining a seal surface;
a stationary component;
a seal body defining a seal face, the seal body defining a fluid feed passage within the seal body, wherein the fluid feed passage includes an inlet, and one or more feed ports defined along the seal face, wherein the seal body is moveably coupled to the stationary component via a resilient member;
a first-pressure plenum defined radially outward from the seal body;
a second-pressure plenum defined radially inward from the seal body; and
a plenum seal forming a seal between a portion of the seal body and the stationary component, wherein the plenum seal, the stationary component, and the seal body at least partially define a third-pressure plenum in fluid communication with a high-pressure fluid source, wherein the third-pressure plenum is in fluid communication with the inlet of the fluid feed passage, and wherein the third-pressure plenum is pressurized at a higher pressure than both the first-pressure plenum and the second-pressure plenum.
2 . The aspirating face seal assembly of claim 1 , wherein an axial gap is defined between the seal face and the seal surface.
3 . The aspirating face seal assembly of claim 1 , wherein the seal body defines a crossbar portion and a seal arm portion.
4 . The aspirating face seal assembly of claim 3 , wherein the fluid feed passage extends axially within the crossbar portion and radially within the seal arm portion of the seal body between the inlet and the one or more feed ports.
5 . The aspirating face seal assembly of claim 1 , wherein the stationary component includes a stationary extension arm, wherein the plenum seal extends from the stationary extension arm to a radially outer surface of the seal body, and wherein the stationary extension arm at least partially defines the third-pressure plenum.
6 . The aspirating face seal assembly of claim 5 , wherein the inlet is defined along the radially outer surface of the seal body.
7 . The aspirating face seal assembly of claim 5 , wherein the seal body defines a radial side wall, wherein the inlet is defined along the radial side wall.
8 . The aspirating face seal assembly of claim 1 , wherein the stationary component includes a stationary arm, wherein the plenum seal extends from the stationary arm to an outer surface of the seal body, and wherein the stationary arm at least partially defines the third-pressure plenum.
9 . The aspirating face seal assembly of claim 8 , wherein the seal body defines an inner pocket, wherein the inner pocket at least partially defines the third-pressure plenum.
10 . The aspirating face seal assembly of claim 9 , wherein the inlet is defined within the inner pocket.
11 . The aspirating face seal assembly of claim 9 , wherein the stationary arm defines a channel extending therein, wherein the channel provides for fluid communication between the high-pressure fluid source and the third-pressure plenum.
12 . The aspirating face seal assembly of claim 9 , wherein the resilient member is disposed outside of the inner pocket.
13 . The aspirating face seal assembly of claim 1 , further comprising a tube, wherein the tube extends from the seal body into the stationary component, wherein the tube at least partially defines the fluid feed passage including the inlet, and wherein the tube is in fluid communication with the high-pressure fluid source and the fluid feed passage.
14 . The aspirating face seal assembly of claim 13 , wherein the plenum seal is slidably engaged with an outer surface of the tube.
15 . The aspirating face seal assembly of claim 13 , wherein the stationary component defines a plenum therein, wherein the plenum defines the third-pressure plenum.
16 . The aspirating face seal assembly of claim 1 , wherein the rotating component includes a primary tooth, and the seal body defines a secondary sealing surface adjacent to the primary tooth.
17 . The aspirating face seal assembly of claim 1 , wherein the rotating component is one of a high-pressure shaft and a low-pressure shaft of a gas turbine engine.
18 . The aspirating face seal assembly of claim 1 , wherein the high-pressure fluid source is one of a high-pressure compressor, a low-pressure compressor, a compressor discharge, or a high-pressure turbine of a gas turbine engine.
19 . The aspirating face seal assembly of claim 1 , wherein the resilient member is a spring or bellows.
20 . The aspirating face seal assembly of claim 1 , wherein the resilient member includes a first end coupled to the stationary component and second end coupled to the seal body, wherein the resilient member biases the seal face of the seal body away from the seal surface of the rotating component.