# US 12,110,797 B1 · Blade outer air seal with seal plate and flexible seal

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- Number: US 12,110,797 B1
- Document ID: US12110797B1
- Status: Granted
- Kind: B1
- Application number: 18/428,450
- Filed: 2024-01-31
- Granted: 2024-10-08
- Earliest claimed: 2024-01-31
- Assignees: Rtx Corporation
- Applicants: Rtx Corporation
- Inventors: Joseph Micucci; Mikayla M. Rogers; Daniel S. Rogers; Danielle Mahoney
- Web page: https://patentgrep.com/patent/US12110797B1

## CPC

- F01D 11/08: for sealing space between rotor blade tips and stator (specially-shaped blade tips therefor F01D5/20)
- C04B 41/009: {characterised by the material treated}
- C04B 41/52: Multiple coating or impregnating {multiple coating or impregnating with the same composition or with compositions only differing in the concentration of the constituents, is classified as single coating or impregnation}
- C04B 41/89: for obtaining at least two superposed coatings having different compositions
- F01D 11/005: {Sealing means between non relatively rotating elements}
- F01D 25/246: {Fastening of diaphragms or stator-rings}
- C04B 2111/00982: {as construction elements for space vehicles or aeroplanes}
- F05D 2230/642: using maintaining alignment while permitting differential dilatation
- F05D 2240/11: Shroud seal segments
- F05D 2240/55: Seals
- F05D 2250/75: given by its similarity to a letter, e.g. T-shaped
- F05D 2260/31: Retaining bolts or nuts
- F05D 2260/36: by a form fit connection, e.g. by interlocking
- F05D 2260/38: by a spring, i.e. spring loaded or biased towards a certain position
- F05D 2300/211: Silica
- F05D 2300/2112: Aluminium oxides
- F05D 2300/501: Elasticity
- F05D 2300/50212: dissimilar
- F05D 2300/6033: Ceramic matrix composites [CMC]
- F05D 2300/611: Coating
- Y02T 50/60: Efficient propulsion technologies, e.g. for aircraft
- F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D)
- C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE
- 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

A gas turbine engine includes a row of blade outer air seal (BOAS) arc segments arranged around an engine axis. Each of the BOAS arc segments includes a ceramic matrix composite (CMC) body that has forward and aft flanges that project from the non-core gaspath side. An annular seal plate is located forward of the forward flange and includes a radially-extending wall, an axially-extending wall that projects forwardly from the radially-extending wall, and a nose that projects aftly from the radially-extending wall. The nose seals against the forward flange. A flexible seal is located in a recess defined by the radially-extending wall and the axially-extending wall. The flexible seal seals against a forward face of the radially-extending wall and is radially spaced apart from a radially outer face of the axially-extending wall.

## Claims

### Claim 1

A gas turbine engine comprising:
a row of blade outer air seal arc segments arranged around an engine axis, each of the blade outer air seal arc segments including a ceramic matrix composite (CMC) body defining a core gaspath side, a non-core gaspath side opposite the core gaspath side, a forward end, an aft end, and circumferential sides, the CMC body having forward and aft flanges projecting from the non-core gaspath side;
an annular seal plate located forward of the forward flange, the annular seal plate including a radially-extending wall, an axially-extending wall projecting forwardly from the radially-extending wall, and a nose projecting aftly from the radially-extending wall, the nose sealing against the forward flange; and
a flexible seal located in a recess defined by the radially-extending wall and the axially-extending wall, the flexible seal sealing against a forward face of the radially-extending wall and the flexible seal being radially spaced apart from a radially outer face of the axially-extending wall.

### Claim 2 (depends on 1)

The gas turbine engine as recited in claim 1, wherein the flexible seal is a W-seal.

### Claim 3 (depends on 2)

The gas turbine engine as recited in claim 2, wherein a tip of the nose is radially inwardly offset from the W-seal.

### Claim 4 (depends on 3)

The gas turbine engine as recited in claim 3, wherein the W-seal includes two convolutes.

### Claim 5 (depends on 1)

The gas turbine engine as recited in claim 1, wherein the nose includes a notch that opens radially-inwardly.

### Claim 6 (depends on 1)

The gas turbine engine as recited in claim 1, wherein at least the forward flange includes a forward face that has a forward flange multi-layered coating against which the nose seals.

### Claim 7 (depends on 6)

The gas turbine engine as recited in claim 6, wherein the multi-layered coating includes a bond layer of silicon and a topcoat of mullite.

### Claim 8 (depends on 6)

The gas turbine engine as recited in claim 6, wherein the aft flange includes an aft face that has an aft flange multi-layered coating that includes a bond layer of silicon and a topcoat of mullite.

### Claim 9 (depends on 8)

The gas turbine engine as recited in claim 8, further comprising a case located aft of the aft flange, the case including a nose that seals against the aft flange multi-layered coating.

### Claim 10 (depends on 9)

The gas turbine engine as recited in claim 9, wherein the forward flange multi-layered coating and the aft flange multi-layered coating include machined surfaces that define a controlled axial length dimension there between.

### Claim 11 (depends on 6)

The gas turbine engine as recited in claim 6, wherein the seal plate is formed of a metallic alloy, and the forward flange multi-layered coating is interposed between the nose and the CMC body.