The present invention generally relates to gas turbine engines, and more particularly, to turbine shrouds used in gas turbine engines.
Gas turbine engines typically include a compressor, a combustor, and a turbine. The compressor compresses air drawn into the engine and delivers high pressure air to the combustor. In the combustor, fuel is mixed with the high pressure air and the air/fuel mixture is ignited. Products of the combustion reaction in the combustor are directed into the turbine where work is extracted to drive various components of the gas turbine engine.
Turbines typically include alternating stages of static vane assemblies and rotatable wheel assemblies. The rotatable wheel assemblies include disks carrying blades that are coupled to the disks. When the rotatable wheel assemblies turn in response to receiving the combustion reaction products, tips of the blades move along ceramic blade tracks included in static turbine shrouds surrounding the rotating wheel assemblies; thereby, work is extracted in the form of mechanical energy.
To maximize the mechanical energy extracted by the turbine, seals are arranged at circumferential interfaces between adjacent segments of the blade track to block leakage of combustion products through the blade track. The seals are sometimes located by slots formed in the blade track segments. Exposure of ceramic blade track segments to the combustion reaction products can result in the degradation of the blade track over time. Coatings are sometimes used to protect ceramic gas turbine engine components. However, applying coatings to the ceramic blade track segments inside seal-locating slots can present design and manufacturing challenges.
The present disclosure may comprise one or more of the following features and combinations thereof.
According to one aspect of the present disclosure, a turbine shroud for a gas turbine engine may include a plurality of ceramic matrix composite blade track segments, a plurality of strip seals, and a plurality of strip-seal support inserts. The plurality of ceramic matrix composite blade track segments may be arranged circumferentially adjacent to one another to form a ring. The plurality of strip seals may be located circumferentially between adjacent ceramic matrix composite blade track segments. The plurality of strip-seal support inserts may be coupled to the ceramic matrix composite segments and formed to include strip-seal slots that receive the plurality of strip seals to hold the strip seals in place relative to the plurality of ceramic matrix composite blade track segments.
In some embodiments, each of the plurality of ceramic matrix composite blade track segments may be formed to include an insert-receiving cavity that receives at least a portion of the strip-seal support insert. Each of the plurality of ceramic matrix composite blade track segments may be bonded to a strip-seal support insert received in the insert-receiving cavity by a braze layer located in the insert-receiving cavity. Each of the plurality of ceramic matrix composite blade track segments may be bonded to a strip-seal support insert received in the insert-receiving cavity by a bond layer located in the insert-receiving cavity.
In some embodiments, each of the strip-seal support inserts may be formed to include a body portion that defines the strip-seal slots, and an attachment portion that is received in an insert-receiving cavity formed in each one of the ceramic matrix composite blade track segments. The attachment portion may be shaped to engage the ceramic matrix composite blade track segment and block circumferential movement of a strip-seal support insert relative to the ceramic matrix composite blade track segment. The attachment portion of each strip-seal support insert may have a dove-tail shape, and the insert-receiving cavity of each ceramic matrix composite blade track segment may include an axially-extending dove-tail shaped channel that receives the attachment portion of each strip-seal support insert. The insert-receiving cavity of each ceramic matrix composite blade track segment may include an axially-extending channel that receives both the body portion and the attachment portion of each strip-seal support insert.
In some embodiments, the plurality of strip-seal support inserts may be constructed from material including a rare earth silicate. The plurality of strip-seal support inserts may be constructed from a material including at least one of an alkaline earth material, an alkaline aluminosilicate material, and mullite.
According to another aspect of the present disclosure, a turbine shroud segment for a gas turbine engine may include a ceramic matrix composite blade track segment, a first strip-seal support insert, and a second strip-seal support insert. The ceramic matrix composite blade track segment may include an arcuate runner that defines a radius around a central axis and an attachment feature adapted to couple the arcuate runner to a turbine case. The first strip-seal support insert may be coupled to a first end of the arcuate runner and formed to include a first strip-seal slot. The first strip-seal slot may be sized to receive a first strip seal and located adjacent to the first end of the arcuate runner. The second strip-seal support insert may be coupled to a second end of the arcuate runner opposite the first end and formed to include a second strip-seal slot. The second strip-seal slot may be sized to receive a second strip seal and located adjacent to the second end of the arcuate runner.
In some embodiments, the ceramic matrix composite blade track segment may be bonded to each of the first strip-seal support insert and the second strip-seal support insert. The first strip-seal support insert and the second strip-seal support insert may be constructed from material including a rare earth silicate. The first strip-seal support insert and the second strip-seal support insert may be constructed from a material including at least one of an alkaline earth material, an alkaline aluminosilicate material, and mullite.
In some embodiments, the ceramic matrix composite blade track segment may be formed to include a first insert-receiving cavity that receives at least a portion of the first strip-seal support insert, and a second insert-receiving cavity that receives at least a portion of the second strip-seal support insert. The first insert-receiving cavity may extend into the arcuate runner from the first end of the arcuate runner toward the second end of the arcuate runner, and the second insert-receiving cavity may extend into the arcuate runner from the second end of the arcuate runner toward the first end of the arcuate runner.
In some embodiments, the first strip-seal support insert and the second strip-seal support insert may each be formed to include a body portion that defines a strip-seal slot, and an attachment portion. The attachment portion may be received in the arcuate runner and shaped to engage the arcuate runner. The attachment portions of the first strip-seal support insert and the second strip-seal support insert may have a dove-tail shape. The first and second insert-receiving cavities of the ceramic matrix composite blade track segment may include an axially-extending channel that receives both the body portion and the attachment portion of the first and second strip-seal support inserts.
According to yet another aspect of the present disclosure, a method of assembling a turbine shroud for a gas turbine engine may include (i) forming a channel in one of a plurality of ceramic matrix composite blade track segments, (ii) positioning a strip-seal support insert in the channel, the strip-seal support insert having a slot formed therein, (iii) positioning a strip seal in the slot such that a portion of the strip seal extends to a point outside of the slot, and (iv) arranging the one ceramic matrix composite blade track segment relative to another ceramic matrix composite blade track segment of the plurality of ceramic matrix composite blade track segments such that the portion is received in a slot of a strip-seal support insert positioned in a channel of the another ceramic matrix composite blade track segment. In some embodiments, the method may include securing the strip-seal support insert in the channel using a braze layer.
For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Any alterations and further modifications in the described embodiments, and any further applications of the principles of the invention as described herein are contemplated as would normally occur to one skilled in the art to which the invention relates.
Referring now to
Referring now to
In operation of the gas turbine engine 10, the vanes 30 of the static vane assembly 20 extend across the flow path of the combustion products delivered to the turbine 16 from the combustor 14 to direct the combustion products toward the plurality of blades 34 of the turbine wheel assembly 24. As a result, the combustion products push the plurality of blades 34 and cause the plurality of blades 34 to rotate.
A turbine shroud assembly 46 included in the turbine 16 is shown in
The turbine blade track 48 of the turbine shroud assembly 46 extends circumferentially to surround the turbine wheel assembly 24 to directly block combustion products delivered to the turbine 16 from passing over the turbine blades 34. Combustion products allowed to pass over the blades 34 of the turbine wheel assembly 24 do not cause the blades 34 to rotate, thereby contributing to lost performance within the engine 10. The turbine blade track 48 includes a plurality of blade track segments 49 as discussed below with regard to
The metallic support ring 50 of the turbine shroud assembly 46 is coupled to the metallic case 18 and extends circumferentially to surround the turbine blade track 48 and support the blade track 48 relative to the case 18 as shown in
The plurality of metallic retainers 52 of the turbine shroud assembly 46 engage a pair of posts 62 of the blade track segments 49 (further discussed below with regard to
The plurality of strip seals 54 are located circumferentially between adjacent blade track segments 49 of the blade track 48 as shown in
The plurality of strip-seal support inserts 56 are illustratively coupled to the blade track segments 49 of the blade track 48 as shown in
Referring now to
The one of the blade track segments 49 shown in
The arcuate runner 64 of the one blade track segment 49, in combination with the arcuate runners included in the other blade track segments 49, define a diameter about a central axis 67 extending longitudinally through the gas turbine engine 10 as suggested in
The attachment feature 68 of the one blade track segment 49 is illustratively embodied as the posts 62 extending radially outwardly from the arcuate runner 64 as shown in
Each of the insert-receiving cavities 65, 66 of the one blade track segment 49 receives at least a portion of one of the strip-seal support inserts 56 as shown in
The insert-receiving cavities 65, 66 form channels 75, 76, respectively, that are sized to receive one of the plurality of strip-seal support inserts 56 as shown in
Referring again to
The strip-seal support inserts 80, 82 are substantially identical to one another as shown in
The strip-seal support insert 80 is illustratively constructed of a rare earth silicate. For example, the strip-seal support insert 80 may be constructed of one of the following: yttrium pyrosilicate, yttrium orthosilicate, ytterbium pyrosilicate, or ytterbium silicate. In other embodiments, however, the strip-seal support insert 80 may be constructed of one of the following: mullite, an alkaline earth material, or an alkaline aluminosilicate material. In still other embodiments, other suitable materials may be used to make the strip-seal support insert 80.
The strip-seal support insert 80 is formed to include a strip-seal slot 84 as shown in
Referring to
Though not shown in
Referring now to
The strip-seal support insert 80 is bonded to the arcuate runner 64 via a bonding layer 96 located in the insert-receiving cavities 65. The bonding layer 96 is positioned between the strip-seal support insert 80 and the arcuate runner 64 as shown in
Referring to
Unlike the blade track segment 49, the blade track segment 149 includes an arcuate runner 164 that is formed to include a first insert-receiving cavity 165 through one end 170 and a second insert-receiving cavity through an opposite end (not shown in
The insert-receiving cavity 165 of the arcuate runner 164 forms a channel 175 that receives the strip-seal support insert 180 as shown in
The strip-seal support insert 180 is formed to include a body portion 181, an attachment portion 183, and a strip-seal slot 184 as shown in
Referring now to
Referring to
Unlike the blade track segment 49, the blade track segment 249 includes an arcuate runner 264 that is formed to include a first insert-receiving cavity 265 through one end 270 and a second insert-receiving cavity through an opposite end (not shown in
The insert-receiving cavity 265 of the arcuate runner 264 forms a channel 275 that receives the strip-seal support insert 280 as shown in
The strip-seal support insert 280 is formed to include a body portion 281, an attachment portion 283, and a strip-seal slot 284 as shown in
Referring now to
Referring to
While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiments have been shown and described and that all changes and modifications that come within the spirit of the inventions are desired to be protected. It should be understood that while the use of words such as preferable, preferably, preferred or more preferred utilized in the description above indicate that the feature so described may be more desirable, it nonetheless may not be necessary and embodiments lacking the same may be contemplated as within the scope of the invention, the scope being defined by the claims that follow. In reading the claims, it is intended that when words such as “a,” “an,” “at least one,” or “at least one portion” are used there is no intention to limit the claim to only one item unless specifically stated to the contrary in the claim. When the language “at least a portion” and/or “a portion” is used the item can include a portion and/or the entire item unless specifically stated to the contrary.
This application claims priority to and the benefit of U.S. Provisional Patent Application No. 62/026,814, filed 21 Jul. 2014, the disclosure of which is now expressly incorporated herein by reference.
Number | Name | Date | Kind |
---|---|---|---|
6312218 | Beeck | Nov 2001 | B1 |
6441341 | Steibel et al. | Aug 2002 | B1 |
6670026 | Steibel et al. | Dec 2003 | B2 |
6935836 | Ress, Jr. et al. | Aug 2005 | B2 |
7329087 | Cairo et al. | Feb 2008 | B2 |
7771159 | Johnson et al. | Aug 2010 | B2 |
7870738 | Zborovsky et al. | Jan 2011 | B2 |
8132442 | Merrill et al. | Mar 2012 | B2 |
8246299 | Razzell | Aug 2012 | B2 |
8322977 | Beeck | Dec 2012 | B2 |
8496431 | Habarou | Jul 2013 | B2 |
20120171027 | Albers | Jul 2012 | A1 |
Number | Date | Country | |
---|---|---|---|
20160017721 A1 | Jan 2016 | US |
Number | Date | Country | |
---|---|---|---|
62026814 | Jul 2014 | US |