Blade outer air seal made of ceramic matrix composite

Patent metadata

Field	Value
Publication number	US-10077670-B2
Application number	US-201414915432-A
Country	US
Kind code	B2
Filing date	Aug 29, 2014
Priority date	Aug 29, 2013
Publication date	Sep 18, 2018
Grant date	Sep 18, 2018

Abstract

One exemplary embodiment of this disclosure relates to a gas turbine engine including an engine case, a retention block attached to the engine case, and a blade outer air seal (BOAS). The BOAS includes a plurality of layers formed of a ceramic matrix composite (CMC) material. At least one of the plurality of layers provides a slot receiving a portion of the retention block.

First claim

What is claimed is:

1. A gas turbine engine, comprising:
an engine case;
a retention block attached to the engine case;
a blade outer air seal (BOAS) including a plurality of layers formed of a ceramic matrix composite (CMC) material, wherein at least one of the plurality of layers provides a slot receiving a portion of the retention block,
wherein the BOAS includes a base structure and an overwrap layer provided over the base structure, and wherein both the base structure and the overwrap layer are provided by a CMC material,
wherein the base structure includes first and second ends at opposite circumferential sides of the BOAS, and a bridge extending between the first and second ends, and
wherein the first and second ends are curved in substantially a C-shape to provide first and second slots.

2. The gas turbine engine as recited in claim 1 , wherein each of the first and second slots receive a portion of the retention block attached to the engine case to support the BOAS relative to the engine case.

3. The gas turbine engine as recited in claim 1 , wherein both the first end and the second end are provided by a CMC material having primary fibers arranged to substantially follow a contour of a respective one of the slots.

4. The gas turbine engine as recited in claim 1 , wherein the bridge is provided by a CMC material having primary fibers extending circumferentially, relative to an engine central longitudinal axis, between the first end and the second end.

5. A gas turbine engine, comprising:
an engine case;
a retention block attached to the engine case;
a blade outer air seal (BOAS) including a plurality of layers formed of a ceramic matrix composite (CMC) material, wherein at least one of the plurality of layers provides a slot receiving a portion of the retention block,
wherein the BOAS includes a base structure and an overwrap layer provided over the base structure, and wherein both the base structure and the overwrap layer are provided by a CMC material, and
wherein the overwrap layer includes a central body portion having a plurality of projections extending therefrom, the plurality of projections contacting the base structure.

6. The gas turbine engine as recited in claim 5 , wherein the central body portion provides a radially inner surface of the BOAS.

7. The gas turbine engine as recited in claim 5 , wherein the overwrap layer includes a fore flap and an aft flap extending from the central body portion, the fore flap and the aft flap providing fore and aft surfaces, respectively, of the BOAS.

8. A blade outer air seal (BOAS), comprising:
a base structure; and
an overwrap layer provided over the base structure;
wherein both the base structure and the overwrap layer are provided by a ceramic matrix composite (CMC) material,
wherein the base structure includes first and second ends at opposite circumferential sides of the BOAS, and a bridge extending between the first and second ends, and
wherein the first and second ends are curved in substantially a C-shape to provide first and second slots facing circumferentially away from a center of the BOAS.

9. The BOAS as recited in claim 8 , wherein both the first end and the second end are provided by a CMC material having primary fibers arranged to substantially follow a contour of a respective one of the first and second slots.

10. The BOAS as recited in claim 8 , wherein the bridge is provided by a CMC material having primary fibers extending circumferentially between the first end and the second end.

11. A method of forming a blade outer air seal (BOAS), comprising:
forming a base structure of a ceramic matrix composite (CMC) material, wherein the step of forming the base structure includes forming a first end of a CMC material, forming a second end of a CMC material, the second end formed separate from the first end, and forming a bridge of a CMC material; and
wrapping an overwrap layer of CMC material over the base structure.

12. The method as recited in claim 11 , wherein the bridge is formed separately from the first end and the second end.

13. The method as recited in claim 11 , wherein the step of forming the base structure includes molding the first end, the second end, and the bridge into a semi-rigid state.

14. The method as recited in claim 11 , wherein the step of forming the overwrap layer over the base structure includes molding the first end, the second end, the bridge and the overwrap layer into a solid state.

Assignees

• United Technologies Corp

Inventors

• Mccaffrey Michael G

Classifications

• F05D2300/6033

  Ceramic matrix composites [CMC] · CPC title

• F01D25/246

  Fastening of diaphragms or stator-rings · CPC title

• F01D11/08 Primary

  for sealing space between rotor blade tips and stator (specially-shaped blade tips therefor F01D5/20) · CPC title

• F05D2230/30

  with deposition of material · CPC title

• F01D25/28

  Supporting or mounting arrangements, e.g. for turbine casing · CPC title