Patent Description:
Gas turbine engines are used to power aircraft, watercraft, power generators, and the like. 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 is ignited. Products of the combustion reaction in the combustor are directed into the turbine where work is extracted to drive the compressor and, sometimes, an output shaft. Left-over products of the combustion are exhausted out of the turbine and may provide thrust in some applications.

Compressors and turbines typically include alternating stages of static vane assemblies and rotating wheel assemblies. The rotating wheel assemblies include disks carrying blades around their outer edges. When the rotating wheel assemblies turn, tips of the blades move along blade tracks included in static shrouds that are arranged around the rotating wheel assemblies. Such static shrouds may be coupled to an engine case that surrounds the compressor, the combustor, and the turbine.

Some shrouds positioned in the turbine may be exposed to high temperatures from products of the combustion reaction in the combustor. Such shrouds sometimes include components made from materials that have different coefficients of thermal expansion. Due to the differing coefficients of thermal expansion, the components of some turbine shrouds expand at different rates when exposed to combustion products. In some examples, coupling such components with traditional arrangements may not allow for the differing levels of expansion and contraction during operation of the gas turbine engine. <CIT> discloses a flow path component assembly comprising a flow path component with a plurality of segments extending circumferentially; at least one of the plurality of segments having a first wall and an axially spaced second wall extending radially outward from a base portion, a coating on a portion of the first wall and a portion of the second wall. The coating is in contact with a feature on the support structure.

The present invention concern a shroud assembly according to claim <NUM>.

A turbine shroud assembly for use with a gas turbine engine includes a carrier assembly, a blade track assembly, and a first biasing member. The carrier assembly including a carrier segment made of metallic materials and arranged circumferentially at least partway around an axis, the carrier segment having an outer wall, a first mount flange that extends radially inward from the outer wall, and a second mount flange axially spaced apart from the first mount flange and that extends radially inward from the outer wall, the second mount flange including a radially extending wall and a chordal seal that extends axially away from the radially extending wall.

In some embodiments, the blade track assembly includes a blade track segment made of ceramic matrix composite materials and a first mount pin assembly, the blade track assembly supported by the carrier to locate the blade track segment radially outward of the axis and define a portion of a gas path of the turbine shroud assembly, and the blade track segment including a shroud wall that extends circumferentially partway around the axis and an attachment feature that extends radially outward from the shroud wall, and the first mount pin assembly including a retainer plug extending axially into the first mount flange and a pin segment extending axially away from the retainer plug, through the attachment feature, and into the second mount flange so as to couple the blade track assembly to the carrier segment. The invention concerns further a method of forming a shroud turbine assembly according to clam <NUM>. Further preferred embodiments of the present invention are described in the appended dependent claims <NUM> to <NUM>.

In some embodiments, the method further includes coupling the black track assembly to the carrier segment via the first mount pin assembly, the first mount pin assembly including a retainer plug extending axially into the first mount flange and a pin segment extending axially away from the retainer plug, through the attachment feature, and into the second mount flange.

In some embodiments, the method further includes arranging the first biasing member axially between the retainer plug of the first pin mount assembly and the pin segment such that a portion of the pin segment engages the attachment feature of the blade track segment so as to bias the attachment feature into sealing engagement with the chordal seal of the second mount flange.

These and other features of the present disclosure will become more apparent from the following description of the illustrative embodiments.

For the purposes of promoting an understanding of the principles of the disclosure, reference will now be made to a number of illustrative embodiments illustrated in the drawings and specific language will be used to describe the same.

An illustrative aerospace gas turbine engine <NUM> includes a fan <NUM>, a compressor <NUM>, a combustor <NUM>, and a turbine <NUM> as shown in <FIG>. The fan <NUM> is driven by the turbine <NUM> and provides thrust for propelling an air vehicle. The compressor <NUM> compresses and delivers air to the combustor <NUM>. The combustor <NUM> mixes fuel with the compressed air received from the compressor <NUM> and ignites the fuel. The hot, high-pressure products of the combustion reaction in the combustor <NUM> are directed into the turbine <NUM> to cause the turbine <NUM> to rotate about an axis <NUM> and drive the compressor <NUM> and the fan <NUM>. In some embodiments, the fan may be replaced with a propeller, drive shaft, or other suitable configuration.

The turbine section <NUM> includes at least one turbine wheel assembly <NUM> and a turbine shroud <NUM> positioned to surround the turbine wheel assembly <NUM> as shown in <FIG>. The turbine wheel assembly <NUM> includes a plurality of blades <NUM> coupled to a rotor disk <NUM> for rotation with the disk <NUM>. The hot, high pressure combustion products from the combustor <NUM> are directed toward the blades <NUM> of the turbine wheel assemblies <NUM> along a gas path <NUM>. The turbine shroud <NUM> is coupled to an outer case <NUM> of the gas turbine engine <NUM> and extends around the turbine wheel assembly <NUM> to block gases from passing over the turbine blades <NUM> during use of the turbine section <NUM> in the gas turbine engine <NUM>.

In the illustrative embodiment, the turbine shroud <NUM> is made up of a number of turbine shroud assemblies <NUM> that each extend circumferentially partway around the axis <NUM> and cooperate to surround the turbine wheel assembly <NUM>. In other embodiments, the turbine shroud <NUM> is annular and non-segmented to extend fully around the central axis <NUM> and surround the turbine wheel assembly <NUM>. In yet other embodiments, certain components of the turbine shroud <NUM> are segmented while other components are annular and non-segmented.

Each turbine shroud assembly <NUM> includes a carrier assembly <NUM>, a blade track assembly <NUM>, and at least one biasing member <NUM>, as shown in <FIG> which are not according to the invention. The carrier assembly <NUM> includes a carrier segment <NUM> made of metallic materials and arranged circumferentially around the axis <NUM>. In the illustrative embodiment, the carrier segment <NUM> includes radially outward extending flanges that are radially aligned with each other and couple to the turbine outer case <NUM>. The carrier segment <NUM> further includes an outer wall <NUM> that extends circumferentially partway around the axis <NUM>. A first mount flange <NUM> extends radially inward from the outer wall <NUM>. A second mount flange <NUM> is axially
spaced apart from the first mount flange <NUM> and extends radially inward from the outer wall <NUM>. The first mount flange <NUM> and the second mount flange <NUM> each also include a circumferential extent that extends along the circumferential extent of the outer wall <NUM>. The first mount flange <NUM> and the second mount flange <NUM> may be first and second faces of the carrier segment.

In the illustrative embodiment, the first mount flange <NUM> is located at an axially forward end of the outer wall <NUM> and the second mount flange <NUM> is located at an axially aft end of the outer wall <NUM>, as shown in <FIG>. The second mount flange <NUM> includes a radially extending wall and a chordal seal <NUM> that extends axially away from the radially extending wall. The chordal seal <NUM> may, in addition to extending axially away from the wall, also extend circumferentially along the circumferential extent of the second mount flange <NUM> so as to seal off gases flowing along the gas path <NUM> radially within the blade track assembly <NUM>.

The blade track assembly <NUM> of the turbine shroud assembly <NUM> includes a blade track segment <NUM> and a first mount pin assembly <NUM>, as shown in <FIG> and <FIG>. The blade track segment <NUM> is made of ceramic matrix composite materials and extends circumferentially partway around the axis <NUM>. The blade track assembly <NUM> is supported by the carrier segment <NUM> to locate the blade track segment <NUM> radially outward of the axis <NUM> and define a portion of the gas path <NUM>. The pin assembly <NUM> may be fixedly held in position via a retainer plug <NUM>.

The blade track segment <NUM> includes a shroud wall <NUM> and at least one attachment feature <NUM>, as shown in <FIG>. The shroud wall <NUM> is arcuate and extends circumferential partway around the axis <NUM> and extends a limited axial distance across the axis <NUM>. The shroud wall <NUM> may extend beyond the second mount flange <NUM> in an axially aft direction. The shroud wall <NUM> includes a radially inner surface <NUM> that faces the gas path <NUM>, and a radially outer surface <NUM> that faces outwardly towards the carrier assembly <NUM>. The inner surface <NUM> cooperates with the turbine wheel assembly <NUM> to block hot gases in the gas path <NUM> from passing over the top of the turbine wheel assembly <NUM>.

The at least one attachment feature <NUM> extends radially outward from the outer surface <NUM> of the shroud wall <NUM>, as shown in <FIG>. In the illustrative embodiment, the at least one attachment feature <NUM> includes a first attachment post <NUM> and a second attachment post <NUM> that is spaced apart from and located axially aft of the first attachment post <NUM>. The first attachment post <NUM> may extend radially away from the shroud wall <NUM> the same distance as the second attachment post <NUM>, although in other embodiments, the first and second attachment posts <NUM>, <NUM> may extend differing distances from the shroud wall <NUM>. The first attachment post <NUM> and the second attachment post <NUM> provide structure for coupling the blade track segment <NUM> to the carrier assembly <NUM>.

In the illustrative embodiment, the carrier segment <NUM> further includes a third mount flange <NUM> that extends radially inward from the outer wall <NUM> of the carrier segment <NUM> and a fourth mount flange <NUM> that extends radially inward from the outer wall <NUM> of the carrier segment and that is spaced apart from and located axially aft of the third mount flange <NUM>, as shown in <FIG> and <FIG>. The third and fourth mount flanges <NUM>, <NUM> may be inner mount flanges or clevises that are both located axially inward of the first mount flange <NUM> and the second mount flange <NUM>. The shroud wall <NUM> of the blade track segment <NUM> may include a radially thicker central section axially aligned with the third and fourth mount flanges <NUM>, <NUM>. As a result, the third and fourth mount flanges <NUM>, <NUM> may extend a shorter distance radially away from the outer wall <NUM> than the first and second mount flanges <NUM>, <NUM>. In some embodiments, the carrier segment <NUM> may only include a third mount flange <NUM> that is axially thicker so as to occupy a similar amount of axial space as the embodiments including both third and fourth mount flanges.

The first attachment post <NUM> extends radially outwardly such that the first attachment post <NUM> is located axially between the first mount flange <NUM> and the third mount flange <NUM>, as shown in <FIG>. The second attachment post <NUM> extends radially outwardly such that the second attachment post <NUM> is located axially between the fourth mount flange <NUM> and the second mount flange <NUM>. The first mount flange <NUM> includes an axially aft facing surface and the first attachment post <NUM> includes an axially forward facing surface. The fourth mount flange <NUM> includes an axially aft facing surface and the second attachment post <NUM> includes an axially forward facing surface.

The turbine shroud assembly <NUM> includes a first biasing member <NUM> located axially between the first mount flange <NUM> and the first attachment post <NUM>, as shown in <FIG> and <FIG> which are not according to the invention. The first biasing member <NUM> abuts the axially aft facing surface of the first mount flange <NUM> and the axially forward facing surface of the first attachment post <NUM> such that the first biasing member <NUM> biases the entire blade track segment <NUM> axially aft such that an axially aft facing wall of the second attachment post <NUM> contacts an axially forward facing surface of the chordal seal <NUM>. The contact between the chordal seal <NUM> and the second attachment post <NUM> creates a seal that prevent hot gases flowing along the gas path <NUM> from escaping radially outwardly.

In the illustrative embodiment, the turbine shroud assembly <NUM> further includes a second biasing member <NUM> located axially between the fourth mount flange <NUM> and the second attachment post <NUM>, as shown in <FIG> and <FIG>. The second biasing member <NUM> abuts the axially aft facing surface of the fourth mount flange <NUM> and the axially forward facing surface of the second attachment post <NUM> such that the second biasing member <NUM> biases the entire blade track segment <NUM> axially aft such that the axially aft facing wall of the second attachment post <NUM> contacts the axially forward facing surface of the chordal seal <NUM>.

The first mount flange <NUM> includes a radially outer biasing member recess <NUM> formed within the first mount flange <NUM> that is recessed away from the axially aft facing wall, as shown in <FIG> and <FIG>. The first mount flange <NUM> may also include a radially inner biasing member recess <NUM> formed within the first mount flange <NUM> that is recessed away from the axially aft facing wall. Likewise, the fourth mount flange <NUM> includes a radially outer biasing member recess <NUM> formed within the fourth mount flange <NUM> that is recessed away from the axially aft facing wall. The fourth mount flange <NUM> may also include a radially inner biasing member recess <NUM> formed within the fourth mount flange <NUM> that is recessed away from the axially aft facing wall.

In the illustrative embodiment, the first attachment post <NUM> also includes a radially outer biasing member recess <NUM> formed within the first attachment post <NUM> that is recessed away from the axially forward facing wall, as shown in <FIG> and <FIG>. The first attachment post <NUM> may also include a radially inner biasing member recess <NUM> formed within the first attachment post <NUM> that is recessed away from the axially forward facing wall. The second attachment post <NUM> also includes a radially outer biasing member recess <NUM> formed within the second attachment post <NUM> that is recessed away from the axially forward facing wall. The second attachment post <NUM> may also include a radially inner biasing member recess <NUM> formed within the second attachment post <NUM> that is recessed away from the axially forward facing wall.

Each of the biasing member recesses <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> is configured to receive a portion of the biasing members <NUM>, <NUM>, as shown in <FIG> and <FIG>. The shape and number of recesses depends on the type of biasing member that is used in the turbine shroud assembly <NUM>. For example, the first and second biasing members <NUM>, <NUM> may each be formed as a wave spring, as shown in <FIG>. The first wave spring <NUM> may have at least one curved portion <NUM> that is arranged in the recess <NUM> formed in the axially aft facing surface of the first mount flange <NUM>. The first wave spring <NUM> may have at least one second curved portion <NUM> that is arranged in the recess <NUM> formed in the axially forward facing surface of the first attachment post <NUM>.

In the illustrative embodiment, the second wave spring <NUM> may have at least one curved portion <NUM> that is arranged in the recess <NUM> formed in the axially aft facing surface of the fourth mount flange <NUM>. The second wave spring <NUM> may have at least one second curved portion <NUM> that is arranged in the recess <NUM> formed in the axially forward facing surface of the second attachment post <NUM>. Each of the first and second wave springs <NUM>, <NUM> may have additional curves, some of which would be located within the recesses <NUM>, <NUM>, <NUM>, and <NUM>, as shown in <FIG>.

In the illustrative embodiment, each wave spring <NUM>, <NUM> is a linear wave spring that includes an elongated, relatively flat body having the curves described above, as shown in <FIG> and <FIG>. Each linear wave spring <NUM>, <NUM> extends radially and is arranged circumferentially adjacent to the first mount pin assembly <NUM>. Each biasing member recess <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> is formed to have walls matching the general shape of the outer linear edges of the wave springs <NUM>, <NUM> such that the wave springs <NUM>, <NUM> fit securely within the recess <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>.

Alternatively, the first biasing member <NUM> and the second biasing member <NUM> may be formed as annular ring springs that circumferentially surround the first mount pin assembly <NUM>, as shown in <FIG>. In this embodiment, the biasing member recesses may be formed as annular recesses such that the annular ends of the ring springs <NUM>, <NUM> may fit within the recesses. As shown in <FIG>, the annular recess formed in the axially aft facing surface of the first mount flange <NUM> may include a radially outer portion and a radially inner portion. The annular recess formed in the axially forward facing surface of the first attachment post <NUM> may include a radially outer portion and a radially inner portion. The annular recess formed in the axially aft facing surface of the fourth mount flange <NUM> may include a radially outer portion and a radially inner portion. The annular recess formed in the axially forward facing surface of the second attachment post <NUM> may include a radially outer portion and a radially inner portion.

In the embodiments discussed above, the turbine shroud assembly <NUM> includes both a first and second attachment post <NUM>, <NUM>, and both a first and second biasing member <NUM>, <NUM>. In other embodiments, the turbine shroud assembly <NUM> may include a single biasing member located between one of the first mount flange <NUM> and the first attachment post <NUM> or the fourth mount flange <NUM> and the second attachment post <NUM>. Likewise, the turbine shroud assembly <NUM> may only include a single, fully radially extending attachment post that extends nearly to the inner surface of the outer wall <NUM>. For example, the turbine shroud assembly <NUM> may only include the second attachment post <NUM>, and only a single biasing spring located between the fourth mount flange <NUM> and the second attachment post <NUM>. As a further example, the turbine shroud assembly <NUM> may only include the first attachment post <NUM>, and only a single biasing spring located between the first mount flange <NUM> and the first attachment post <NUM>. In this case, the blade track segment <NUM> includes a radially extending wall where the second attachment post <NUM> is located in <FIG> and <FIG>, but that only extends radially outward far enough such that it contacts the chordal seal <NUM>. This configuration including the radially extending wall that only extends far enough such that it contacts the chordal seal <NUM> is applicable to all other embodiments disclosed herein.

In the illustrative embodiment, the turbine shroud assembly <NUM> includes the first mount pin assembly <NUM>, as shown in <FIG>. In some embodiments, the first mount pin assembly <NUM> is formed as a single pin that is inserted through the first mount flange <NUM>, as shown in <FIG>. The first mount pin assembly <NUM> may have a circular cross-section, or may have any other suitable cross-section. The first mount pin assembly <NUM> may be formed as a single monolithic pin that extends through the first mount flange <NUM>, the first attachment post <NUM>, the third and fourth mount flanges <NUM>, <NUM>, the second attachment post <NUM>, and into the second mount flange <NUM>.

In other embodiments, the first mount pin assembly <NUM> is a split-pin fastener that includes a forward pin <NUM> that extends into the first mount flange <NUM>, through the first attachment post <NUM>, and through the third mount flange <NUM>, and an aft pin <NUM> circumferentially aligned with and aft of the forward pin <NUM> that extends through the fourth mount flange <NUM>, through the second attachment post <NUM>, and into the second mount flange <NUM>, and shown in <FIG>. The forward pin <NUM> is separate from the aft pin <NUM> so as to allow for independent loading during use in the gas turbine engine.

Another embodiment of a turbine shroud assembly <NUM> in accordance with the present invention is shown in <FIG> and <FIG>. The turbine shroud assembly <NUM> is substantially similar to the turbine shroud assembly <NUM> shown in <FIG> and described herein. Accordingly, similar reference numbers in the <NUM> series indicate features that are common between the turbine shroud assembly <NUM> and the turbine shroud assembly <NUM>. The description of the turbine shroud assembly <NUM> is incorporated by reference to apply to the turbine shroud assembly <NUM>, except in instances when it conflicts with the specific description and the drawings of the turbine shroud assembly <NUM>.

The turbine shroud assembly <NUM> includes a carrier assembly <NUM> having a carrier segment <NUM>, a blade track assembly <NUM> having a blade track segment <NUM>, a first mount pin assembly <NUM>, and a first biasing member <NUM>, as shown in <FIG> and <FIG>. In this embodiment, the pin assembly <NUM> biases the blade track assembly <NUM> into the seal <NUM> arranged on the second mount flange <NUM>. The carrier segment <NUM> is made of metallic materials. The carrier segment <NUM> further includes an outer wall <NUM> that extends circumferentially partway around the axis <NUM>. A first mount flange <NUM> extends radially inward from the outer wall <NUM>. A second mount flange <NUM> is axially spaced apart from the first mount flange <NUM> and extends radially inward from the outer wall <NUM>. The carrier segment <NUM> further includes a third mount flange <NUM> that extends radially inward from the outer wall <NUM> of the carrier segment <NUM> and a fourth mount flange <NUM> that extends radially inward from the outer wall <NUM> of the carrier segment and that is spaced apart from and located axially aft of the third mount flange <NUM>.

The blade track segment <NUM> includes a shroud wall <NUM> and at least one attachment feature <NUM>, as shown in <FIG>. The shroud wall <NUM> includes a radially inner surface <NUM> that faces the gas path <NUM>, and a radially outer surface <NUM> that faces outwardly towards the carrier assembly <NUM>. The inner surface <NUM> cooperates with the turbine wheel assembly <NUM> to block hot gases in the gas path <NUM> from passing over the top of the turbine wheel assembly <NUM>. The blade track segment <NUM> includes at least one attachment feature <NUM> that extends radially outward from the outer surface <NUM> of the shroud wall <NUM>. In the illustrative embodiment, the at least one attachment feature <NUM> includes a first attachment post <NUM> and a second attachment post <NUM> that is spaced apart from and located axially aft of the first attachment post <NUM>.

In the illustrative embodiment, the turbine shroud assembly <NUM> includes the first mount pin assembly <NUM>, as shown in <FIG> and <FIG>. The first mount pin assembly <NUM> includes a retainer plug <NUM> that extends axially into the first mount flange <NUM> and a pin segment that extends axially away from the retainer plug <NUM>, through the attachment feature <NUM>, and into the second mount flange <NUM> so as to couple the blade track assembly <NUM> to the carrier segment <NUM>.

In some embodiments, the pin segment may have a circular cross-section, or may have any other suitable cross-section. The pin segment may be formed as a single monolithic pin that extends through the first mount flange <NUM>, the first attachment post <NUM>, the third and fourth mount flanges <NUM>, <NUM>, the second attachment post <NUM>, and into the second mount flange <NUM>. In other embodiments, the pin segment is a split-pin fastener that includes a forward pin <NUM> that extends into the first mount flange <NUM>, through the first attachment post <NUM>, and through the third mount flange <NUM>, and an aft pin <NUM> circumferentially aligned with and aft of the forward pin <NUM> that extends through the fourth mount flange <NUM>, through the second attachment post <NUM>, and into the second mount flange <NUM>. The forward pin <NUM> is separate from the aft pin <NUM> so as to allow for independent loading during use in the gas turbine engine.

In the illustrative embodiment in which the pin segment is a split-pin fastener, the forward pin <NUM> includes an aft axial end face and a connection tab <NUM> having a smaller diameter than the forward pin that extends axially away from the aft axial end face, as shown in <FIG> and <FIG>. The aft pin <NUM> includes a forward axial end face and a connection pocket that receives the connection tab <NUM>. The connection tab <NUM> and connection pocket are sized such that the aft axial end face of the forward pin <NUM> and the forward axial end face of the aft pin <NUM> contact each other.

In the illustrative embodiment, the first mount flange <NUM> includes an axially-extending installation aperture that receives a portion of the retainer plug <NUM> and a portion of the forward axial end of the pin segment, as shown in <FIG> and <FIG>. The retainer plug <NUM> includes an outer cap formed axially adjacent to the portion of the retainer plug <NUM> arranged within the axially-extending installation aperture. The outer cap fixedly retains the retainer plug <NUM> against the axially outer surface of the first mount pin so as to prevent removal of the first mount pin assembly <NUM>. The retaining plug <NUM> may be press fit, threaded, tack welded in place, retained by the vane in front of it, or a combination of the aforementioned methods. The radially extending wall of the second mount flange <NUM> includes an axially extending recess <NUM> within which an aft axial end of the pin segment is arranged. An axial space is formed between the axial end of the pin segment and an inner axial wall of the recess <NUM>.

In the illustrative embodiment, the first biasing member <NUM> is arranged between the portion of the retain plug <NUM> that extends into the first mount flange <NUM> and the portion of the forward axial end of the pin segment that also extends into the first mount flange <NUM>, as shown in <FIG> and <FIG>. The pin segment includes a first step <NUM> defining an axially facing step face. As shown in <FIG>, the axially facing step face of the first step <NUM> abuts the axially forward facing surface of the first attachment post <NUM>. Due to the retainer plug <NUM> being fixed in place, the pin segment is axially biased away from the retainer plug <NUM> by the first biasing member <NUM>. As a result, the axially facing step face of the first step <NUM> is biased into the first attachment post <NUM> and in turn the second attachment post <NUM> into sealing engagement with the chordal seal <NUM>.

Alternatively, as shown in <FIG>, the axially facing step face of the first step <NUM> abuts the axially forward facing surface of the second attachment post <NUM> such that the biasing of the pin segment via the first biasing member <NUM> biases the axially facing step face of the first step <NUM> into the second attachment post <NUM> and into sealing engagement with the chordal seal <NUM>. In the illustrative embodiments, the first biasing member <NUM> may be formed as a ring spring. Other suitable springs may be used as well so long as the pin segment is sufficiently biased into engagement with the chordal seal <NUM>.

Another embodiment of a turbine shroud assembly <NUM> which is not according to the invention is shown in <FIG>. The turbine shroud assembly <NUM> is substantially similar to the turbine shroud assembly <NUM> and the turbine shroud assembly <NUM> shown in <FIG> and described herein. Accordingly, similar reference numbers in the <NUM> series indicate features that are common between the turbine shroud assembly <NUM> and the turbine shroud assembly <NUM>. The description of the turbine shroud assembly <NUM> is incorporated by reference to apply to the turbine shroud assembly <NUM>, except in instances when it conflicts with the specific description and the drawings of the turbine shroud assembly <NUM>.

The turbine shroud assembly <NUM> includes a carrier assembly <NUM> having a carrier segment <NUM>, a blade track assembly <NUM> having a blade track segment <NUM>, a first mount pin assembly <NUM>, a first biasing member <NUM>, and a second biasing member <NUM> as shown in <FIG>. In this embodiment, the first and second biasing members <NUM>, <NUM> bias the blade track assembly <NUM> into the seal <NUM> arranged on the second mount flange <NUM>. The carrier segment <NUM> is made of metallic materials. The carrier segment <NUM> further includes an outer wall <NUM> that extends circumferentially partway around the axis <NUM>. A first mount flange <NUM> extends radially inward from the outer wall <NUM>. A second mount flange <NUM> is axially spaced apart from the first mount flange <NUM> and extends radially inward from the outer wall <NUM>. The carrier segment <NUM> further includes a third mount flange <NUM> that extends radially inward from the outer wall <NUM> of the carrier segment <NUM> and a fourth mount flange <NUM> that extends radially inward from the outer wall <NUM> of the carrier segment and that is spaced apart from and located axially aft of the third mount flange <NUM>.

The turbine shroud assembly <NUM> includes the first mount pin assembly <NUM>, as shown in <FIG>. The first mount pin assembly <NUM> includes a retainer plug <NUM> that extends axially into the second mount flange <NUM> and a pin segment that extends axially away from the retainer plug <NUM>, through the attachment feature <NUM>, and into the first mount flange <NUM> so as to couple the blade track assembly <NUM> to the carrier segment <NUM>.

In the illustrative embodiment, the turbine shroud assembly <NUM> includes a first biasing member <NUM> and a second biasing member <NUM>, the first and second biasing members <NUM>, <NUM> being braid seals that extend circumferentially at least partway around the blade track segment <NUM>, as shown in <FIG>. The first braid seal <NUM> is located axially between the first mount flange <NUM> and the first attachment post <NUM>. The first braid seal <NUM> abuts the axially aft facing surface of the first mount flange <NUM> and the axially forward facing surface of the first attachment post <NUM> such that the first braid seal <NUM> biases the entire blade track segment <NUM> axially aft such that an axially aft facing wall of the second attachment post <NUM> contacts an axially forward facing surface of the chordal seal <NUM>.

In the illustrative embodiment, the turbine shroud assembly <NUM> further includes a second braid seal <NUM> located axially between the fourth mount flange <NUM> and the second attachment post <NUM>, as shown in <FIG>. The second braid seal <NUM> abuts the axially aft facing surface of the fourth mount flange <NUM> and the axially forward facing surface of the second attachment post <NUM> such that the second braid seal <NUM> biases the entire blade track segment <NUM> axially aft such that the axially aft facing wall of the second attachment post <NUM> contacts the axially forward facing surface of the chordal seal <NUM>. Similarly to the previous embodiments, the turbine shroud assembly <NUM> may include only a single braid seal or a single attachment post.

Another embodiment of a turbine shroud assembly <NUM> which is not according to the invention is shown in <FIG>. The turbine shroud assembly <NUM> is substantially similar to the turbine shroud assembly <NUM>, the turbine shroud assembly <NUM>, and the turbine shroud assembly <NUM> shown in <FIG> and described herein. Accordingly, similar reference numbers in the
<NUM> series indicate features that are common between the turbine shroud assembly <NUM> and the turbine shroud assembly <NUM>. The description of the turbine shroud assembly <NUM> is incorporated by reference to apply to the turbine shroud assembly <NUM>, except in instances when it conflicts with the specific description and the drawings of the turbine shroud assembly <NUM>.

In the illustrative embodiment, the turbine shroud assembly <NUM> includes a first biasing member <NUM> and a second biasing member <NUM>, the first and second biasing members <NUM>, <NUM> being radial springs, as shown in <FIG>. A radial portion <NUM> of the first radial spring <NUM> is located between and abuts a radially inner surface of the outer wall <NUM> of the carrier segment and a radially outer surface of the first attachment post <NUM>. Likewise, a radial portion <NUM> of the second radial spring <NUM> is located between and abuts a radially inner surface of the outer wall <NUM> of the carrier segment and a radially outer surface of the second attachment post <NUM>. The radial springs <NUM>, <NUM> further include radially extending portions <NUM>, <NUM> that extend radially inwardly away from the radial portions <NUM>, <NUM>. The radial portions <NUM>, <NUM> of the first and second radial springs <NUM>, <NUM> are biased radially inwardly, which in turn causes the radially extending portions <NUM>, <NUM> to be biased in the axially aft direction. As such, the radially extending portions <NUM>, <NUM> bias the first and second attachment posts <NUM>, <NUM> in the axially aft direction, and thus the second attachment post <NUM> into sealing engagement with the chordal seal <NUM> of the second mount flange <NUM>.

In at least some embodiments, a turbine shroud assembly includes a wave spring that is placed between an aft side of an inner clevis of a carrier segment of the turbine shroud assembly and an aft leg of a CMC blade track segment. Alternatively, a wave spring may be placed between a forward vertical leg extending away from the carrier segment and a front leg of the CMC blade track segment. As a further alternative, a wave spring may be placed between both the inner clevis and aft leg of the CMC blade track segment and the front carrier leg and the front leg of the CMC blade track segment. The wave spring is compressed upon installation and forces the seal segment aft and into contact with a chordal seal of the carrier segment. Such an embodiment may be utilized with a single mount pin or a split-pin assembly, both of which are inserted through the forward leg of the carrier segment. The wave spring could be of a typical ring configuration, linear wave springs, or both. The ring configuration may be arranged around the mount pin and be self-contained.

In an alternative embodiment, a stepped pin is inserted through the forward leg of the carrier segment. The stepped pin is configured such that the major diameter of the pin is larger than the hole in the aft flange or forward flange of the CMC blade track segment. This allows the pin to push aft on the CMC blade track segment. A spring, such as a coil, wave spring, ring spring, or Bellville washer, is inserted in front of the pin and is compressed by a retaining cap. The retaining cap also acts to retain the pin and seal in the cavity from air leaks. The retaining cap may be press fit, threaded, tack welded in place, retained by the vane in front of it, or a combination of the aforementioned methods. Alternatively, the mount pin may include two pins or be a split-pin assembly in which the forward pin has a single large diameter and the aft pin is stepped as discussed above.

In order to facilitate ease of installation, the forward pin may have a nose that inserts into the aft pin. In other embodiments, the mount pin may be inserted from the aft side through an aft leg or flange extending from the outer wall of the carrier segment. The embodiments including the pin inserted from the forward end are simpler to install, provide more options for the type of spring and the location of the spring, and any leakage is to a higher pressure source, reducing the leakage relative to an aft inserted pin. Also, such embodiments can use the vane to retain the plug, thus eliminating any tack welding.

Claim 1:
A turbine shroud assembly (<NUM>) for use with a gas turbine engine (<NUM>), the turbine shroud assembly (<NUM>) comprising
a carrier segment (<NUM>) arranged circumferentially at least partway around an axis (<NUM>), the carrier segment (<NUM>) having a first mount flange (<NUM>) that extends radially inward and a second mount flange (<NUM>) axially spaced apart from the first mount flange (<NUM>) and that extends radially inward, the second mount flange (<NUM>) including a radially extending wall and a chordal seal (<NUM>) that extends axially away from the radially extending wall,
a blade track assembly (<NUM>) including a blade track segment (<NUM>) and a first mount pin assembly (<NUM>), the blade track segment (<NUM>) including a shroud wall (<NUM>) and an attachment feature (<NUM>) that extends radially outward from the shroud wall (<NUM>), and the first mount pin assembly (<NUM>) coupling the blade track assembly (<NUM>) to the carrier segment (<NUM>) and including a retainer plug (<NUM>) extending axially into the first mount flange (<NUM>) and a pin segment (<NUM>, <NUM>) extending axially away from the retainer plug (<NUM>), and characterised by
a first biasing member (<NUM>) arranged axially between and engaged with the retainer plug (<NUM>) of the first mount pin assembly (<NUM>) and the pin segment (<NUM>, <NUM>) such that a portion of the pin segment (<NUM>, <NUM>) engages the attachment feature (<NUM>) of the blade track segment (<NUM>) so as to bias the attachment feature (<NUM>) into engagement with the chordal seal (<NUM>) of the second mount flange (<NUM>).