Flexible interface coupling
An air cycle system for a gas turbine engine includes a heat exchanger having an air cycle inlet. An air cycle machine includes an air cycle machine outlet and an annular flexible interface coupling connecting the air cycle inlet to the outlet. The flexible interface coupling includes a receiving portion having a flared region across which a diameter of a heat exchanger portion increases and a landing portion across which the diameter of the heat exchanger portion is maintained. An air cycle machine portion is received in the receiving portion and includes an outlet flange and a diffuser radially inward of the outlet flange. The outlet flange includes a radially outward facing surface contacting a radially inward facing surface of the landing portion. The diffuser is configured to move axially and radially relative to the outlet flange.
1 . An air cycle system for a gas turbine engine comprising:
a heat exchanger including an air cycle inlet;
an air cycle machine including an air cycle machine outlet; and
an annular flexible interface coupling connecting the air cycle inlet to the outlet, wherein the flexible interface coupling includes:
a receiving portion having a flared region across which a diameter of a heat exchanger portion increases and a landing portion across which the diameter of the heat exchanger portion is maintained, and
an air cycle machine portion received in the receiving portion and including an outlet flange and a diffuser radially inward of the outlet flange, the outlet flange including a radially outward facing surface contacting a radially inward facing surface of the landing portion, and wherein the diffuser is configured to move axially and radially relative to the outlet flange.
2 . The air cycle system of claim 1 , wherein the air cycle machine is vibrationally isolated from the heat exchanger via the flexible interface coupling.
3 . The air cycle system of claim 1 , wherein the radially outward facing surface of the outlet flange includes at least one spring energized seal.
4 . The air cycle system of claim 3 , wherein the air cycle system includes a plurality of spring energized seals configured to allow the diffuser to move axially and radially relative to the outlet flange, and wherein the at least one spring energized seal is a subset of the plurality of spring energized seals.
5 . The air cycle system of claim 1 , wherein the outlet flange is connected to the air cycle machine via a retaining plate.
6 . The air cycle system of claim 5 , wherein the retaining plate is affixed to the outlet flange via at least one fastener.
7 . The air cycle system of claim 1 , wherein an axial end of the diffuser is at a first axial position while the air cycle system is in an off state, relative to a centerline axis of the annular flexible interface coupling, and wherein an axial end of the outlet flange is at the first axial position while the air cycle system is in the off state.
8 . The air cycle system of claim 7 , wherein the axial end of the diffuser is radially inward of the axial end of the outlet flange by at least a first radius while the air cycle system is in the off state.
9 . The air cycle system of claim 1 , wherein a wall defining the flared region and the landing portion includes at least one cavity.
10 . The air cycle system of claim 9 , wherein the at least one cavity is configured to receive a heated fluid while the air cycle system is operational.
11 . The air cycle system of claim 1 , wherein the heat exchanger is rigidly mounted to an aircraft engine.
12 . The air cycle system of claim 11 , wherein the air cycle machine is a rotating machine including at least one of a compressor and a turbine.
13 . The air cycle system of claim 1 , wherein at least one of an interior surface of the receiving portion and an exterior surface of the outlet flange includes a low friction coating.
14 . The air cycle system of claim 13 , wherein the low friction coating is a polytetrafluoroethylene coating.
15 . A method for reducing vibrational transfer between a heat exchanger and an air cycle machine, the method comprising:
connecting a fluid inlet of the heat exchanger to a fluid outlet of the air cycle machine using a flexible inlet coupler, the flexible inlet coupler being configured to vibrationally isolate the air cycle machine from the heat exchanger by allowing a diffuser of the air cycle machine to move axially and radially relative to a centerline axis of the flexible inlet coupler,
wherein the flexible inlet coupler includes a receiving portion having a flared region across which a diameter of the heat exchanger portion increases and a landing portion across which the diameter of the heat exchanger portion is maintained, and an air cycle machine portion received in the receiving portion and including an outlet flange and a diffuser radially inward of the outlet flange, the outlet flange including a radially outward facing surface contacting a radially inward facing surface of the landing portion.
16 . The method of claim 15 , further comprising maintaining a temperature of the flexible inlet coupling above freezing temperatures by providing a heated fluid from the heat exchanger into at least one cavity defined within a wall defining the receiving portion.
17 . The method of claim 15 , wherein an axial end of the diffuser is at a first axial position while the air cycle system is in an off state, relative to a centerline axis of the annular flexible interface coupling, and wherein an axial end of the retaining flange is at the first axial position while the air cycle system is in the off state.
18 . The method of claim 17 , wherein the axial end of the diffuser is radially inward of the axial end of the retaining flange by at least a first radius while the air cycle system is in the off state.