# US 11,999,501 B2 · Exhaust duct assembly and aircraft including the same

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- Number: US 11,999,501 B2
- Document ID: US11999501B2
- Status: Granted
- Kind: B2
- Application number: 18/247,083
- Filed: 2020-10-27
- Published: 2023-12-21
- Granted: 2024-06-04
- Earliest claimed: 2020-10-14
- Assignees: Hanwha Aerospace Co., Ltd.; Pratt & Whitney Canada Corp.
- Applicants: Pratt & Whitney Canada Corp.; Hanwha Aerospace Co., Ltd.
- Inventors: Young Jung Joo; Guy Lefebvre; Jacob Biernat
- Web page: https://patentgrep.com/patent/US11999501B2

## CPC

- B64D 33/04: of exhaust outlets or jet pipes
- F01D 11/005: {Sealing means between non relatively rotating elements}
- F01D 25/30: Exhaust heads, chambers, or the like
- F02K 1/40: Nozzles having means for dividing the jet into a plurality of partial jets or having an elongated cross-section outlet
- F05D 2220/323: for aircraft propulsion, e.g. jet engines
- F05D 2220/324: to drive unshrouded, low solidity propeller
- F05D 2240/55: Seals
- F05D 2260/941: particularly aimed at mechanical or thermal stress reduction
- Y02T 50/40: Weight reduction
- B64D: EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT
- F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D)
- F02K: JET-PROPULSION PLANTS (features of jet-propulsion plants common to gas-turbine plants, air intakes or fuel supply control of air-breathing jet-propulsion plants F02C7/00, F02C9/00)
- F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

An aircraft has an exhaust duct assembly disposed in a low-pressure turbine portion of a gas turbine engine to discharge exhaust gas to the outside and includes a duct having an inlet through which an exhaust gas is introduced, an exhaust portion through which the exhaust gas is exhausted, and a mounting bore formed therethrough; a duct housing in which the duct is disposed therein, and including a mounting hole into which the exhaust portion is inserted; a shaft housing disposed inside the mounting bore, inserted into the duct housing so that one end thereof faces the inlet of the duct, and having a driving axis of the low-pressure turbine portion disposed therein; and a sealing portion having a ring shape, being coupled to one end of the shaft housing, and maintaining airtightness between the driving axis and the shaft housing.

## Claims

### Claim 1

An exhaust duct assembly disposed in a low-pressure turbine portion of a gas turbine engine to discharge an exhaust gas to the outside, the exhaust duct assembly comprising:
a duct comprising an inlet through which the exhaust gas is introduced, an exhaust portion through which the exhaust gas is exhausted, and a mounting bore formed therethrough;
a duct housing in which the duct is disposed therein, and comprising a mounting hole into which the exhaust portion is inserted;
a shaft housing disposed inside the mounting bore of the duct, inserted into the duct housing so that a first end thereof faces the inlet of the duct, and having a driving axis of the low-pressure turbine portion disposed therein, the shaft housing having a second end opposite the first end and defining an axially facing annular seat around the driving axis; and
a sealing portion having a ring shape, being coupled to the second end of the shaft housing, and maintaining airtightness between inner and outer sides of the shaft housing;
wherein the sealing portion has a main ring body and a plurality of mounting tabs projecting radially inwardly from an inner circumferential surface of the main ring body, the circumferentially interrupted points of contact with the axially facing annular seat of the shaft housing, and
wherein bolts extend through the plurality of mounting tabs for bolting the sealing portion to the axially facing annular seat of the shaft housing.

### Claim 2 (depends on 1)

The exhaust duct assembly of claim 1,
wherein the shaft housing comprises an annular protruding portion extending axially from the second end, the annular protruding portion having a radially outer diameter surface, and wherein the axially facing annular seat extends circumferentially around the annular protruding portion, the radially outer diameter surface of the annular protruding portion and the axially facing surface forming a step, and
wherein the main ring body of the sealing portion is spaced radially outwardly from the radially outer diameter surface of the annular protruding portion.

### Claim 3 (depends on 2)

The exhaust duct assembly of claim 2, wherein the sealing portion comprises
a plurality of sealing guides arranged side by side in a longitudinal direction of the main ring body on an outer circumferential surface of the main ring body, each of the sealing guides extending circumferentially around the driving axis.

### Claim 4 (depends on 3)

The exhaust duct assembly of claim 3, wherein the inner circumferential surface of the main ring body is spaced apart from an outer circumferential surface of the shaft housing by a radial distance (h).

### Claim 5

An aircraft comprising a gas turbine engine having an exhaust duct assembly disposed in a low-pressure turbine portion to discharge an exhaust gas to the outside,
wherein the exhaust duct assembly comprises:
a duct comprising an inlet through which the exhaust gas is introduced, an exhaust portion through which the exhaust gas is exhausted, and a mounting bore formed therethrough;
a duct housing in which the duct is disposed therein, and comprising a mounting hole into which the exhaust portion is inserted;
a shaft housing disposed inside the mounting bore of the duct, inserted into the duct housing so that a first end thereof faces the inlet of the duct, and having a driving axis of the low-pressure turbine portion disposed therein, the shaft housing having a second end opposite the first end and defining an axially facing annular seat around the driving axis; and
a sealing portion having a ring shape, being coupled to the second end of the shaft housing, and maintaining airtightness between inner and outer sides of the shaft housing;
wherein the sealing portion has a main ring body and a plurality of mounting tabs projecting radially inwardly from an inner circumferential surface of the main ring body, the plurality of mounting tabs circumferentially spaced-apart around the driving axis to provide circumferentially interrupted points of contact with the axially facing annular seat of the shaft housing, and
wherein bolts extend through the plurality of mounting tabs for bolting the sealing portion to the axially facing annular seat of the shaft housing.

### Claim 6 (depends on 5)

The aircraft of claim 5, wherein the shaft housing comprises an annular protruding portion extending axially from the second end, the annular protruding portion having a radially outer diameter surface, and wherein the axially facing annular seat extends circumferentially around the annular protruding portion, the radially outer diameter surface of the annular protruding portion and the axially facing surface forming a step, and
wherein the main ring body of the sealing portion is spaced radially outwardly from the radially outer diameter surface of the annular protruding portion.

### Claim 7 (depends on 6)

The aircraft of claim 6, wherein the sealing portion comprises a plurality of sealing guides arranged side by side in a longitudinal direction of the main ring body on an outer circumferential surface of the main ring body, each of the sealing guides extending circumferentially around the driving axis.

### Claim 8 (depends on 7)

The exhaust duct assembly of claim 7, wherein the inner circumferential surface of the main ring body is spaced apart from an outer circumferential surface of the shaft housing by a radial distance (h).