Turbine shroud engagement arrangement and method

BACKGROUND OF THE INVENTION

0001The subject matter disclosed herein relates to turbine shrouds and more specifically to systems and methods for attaching such shrouds to one another.

BRIEF DESCRIPTION OF THE INVENTION

0002According to one aspect of the invention a turbine shroud engagement arrangement includes an outer shroud having at least one of a channel formed in and a protruding member extending from an inner radial surface thereof and an inner shroud operably connectable with the outer shroud having at least one of a protruding member extending from an outer radial surface thereof that is complementary to the at least one channel of the outer shroud or a channel formed in the outer radial surface that is complementary to the at least one protruding member of the outer shroud. The turbine shroud engagement arrangement is primarily axially slidably engagable and configured to radially support the inner shroud relative to the outer shroud.

0003According to another aspect of the invention, a method of attaching an inner shroud to an outer shroud of a turbine includes primarily axially slidably engaging a protruding member of at least one of an inner shroud or an outer shroud into a channel in the other of the inner shroud and the outer shroud.

0004These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

0005The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which: <ul id="ul0001" list-style="none"><li><figref idref="f0001">FIG. 1</figref> depicts a perspective view of an embodiment of a turbine shroud engagement arrangement disclosed herein with a portion of an inner shroud removed;</li><li><figref idref="f0002">FIG. 2</figref> depicts an alternate perspective view of the turbine shroud engagement arrangement of <figref idref="f0001">FIG. 1</figref>;</li><li><figref idref="f0003">FIG. 3</figref> depicts a cross sectional view of a tortuous seal employed in the embodiment of <figref idref="f0001">Figures 1</figref> and <figref idref="f0002">2</figref>;</li><li><figref idref="f0003">FIG. 4</figref> depicts a cross sectional view of an alternate tortuous seal disclosed herein;</li><li><figref idref="f0004">FIG. 5</figref> depicts an end view of an alternate embodiment of a turbine shroud engagement arrangement disclosed herein;</li><li><figref idref="f0005">FIG. 6</figref> depicts a schematic view of an alternate embodiment of a turbine shroud engagement arrangement disclosed herein; and</li><li><figref idref="f0005">FIG. 7</figref> depicts a perspective view of the embodiment of <figref idref="f0005">FIG. 6</figref> with a portion of the inner shroud removed.</li></ul>

0006The detailed description explains embodiments of the invention, together with advantages and features, by way of example with reference to the drawings.

DETAILED DESCRIPTION OF THE INVENTION

0007Referring to <figref idref="f0001">Figures 1</figref> and <figref idref="f0002">2</figref>, an embodiment of a turbine shroud engagement arrangement is illustrated at 10. The shroud engagement arrangement 10 includes an outer shroud 14 and an inner shroud 18 engagable therewith. The outer shroud 14 has a channel 22 formed on an inner radial surface 26 thereof, while the inner shroud 18 has a body 30 with a protruding member 34 extending radially outwardly of an outer radial surface 38 thereof. The protruding member 34 is configured such that a perimetrical dimension 42 at a distal portion 46 is greater than a perimetrical dimension 52 at a proximal portion 56. In this embodiment the protruding member 34 is T-shaped, and is slidably engagable in the channel 22 that has a cross sectional shape that is complementary to that of the protruding member 34 and, as such, in this embodiment also is T-shaped. The inner shroud 18 is therefore radially retained by the outer shroud 14 by the engagement of the protruding member 34 within the channel 22. Although not specifically illustrated, other configurations of the protruding member 34 and the channel 22 are contemplated such as a dove tail configuration, for example. Also, the parts on which the protruding member 34 and the channel 22 are formed could be swapped. That is the protruding member 34 could extend from the inner radial surface 26 of the outer shroud 14 and the channel 22 could be formed in the outer radial surface 38 of the inner shroud 18 while not deviating from the invention disclosed herein. Additionally, the body 30 could be part of the outer shroud 14 instead of being part of the inner shroud 18.

0008The slidable engagement of the protruding member 34 into the channel 22 is primarily in an axial direction, the axial direction being defined as parallel to an axis of the turbine. As such, primarily axial herein means that the slidable engagement has a greater axial component than non-axial component. In fact, the shroud engagement arrangement 10 of this embodiment has only an axial component. In contrast, the embodiment of <figref idref="f0005">Figures 6 and 7</figref> includes a non-axial component as will be elaborated on below. Additionally this embodiment has a shoulder 60 on one end of the channel 22 that serves as a stop to prevent further axial movement of the body 30 relative to the outer shroud 14.

0009The outer shroud 14 illustrated has a single piece construction while the inner shroud 18 is formed of a plurality of the bodies 30. Each of the bodies 30 has one of the protruding members 34 slidably engagable with one of the channels 22. This configuration allows each of the bodies 30 to be removable from the outer shroud 14 independently of the other bodies 30, thereby simplifying removal and repair in the field, for example.

0010A detail 64, illustrated herein as a threaded hole, in each of the bodies 30 allows a tool such as a threaded rod (not shown) to threadable engage therewith to aid in slidably removing the bodies 30 from the outer shroud 14. Alternate configurations of the detail 64 are contemplated, that provide for attachment of a tool to axially pull on the bodies 30 relative to the outer shroud 14, such as a cross pin (not shown) in a recess, for example. The shrouds 14 and 18 can also include a feature 66 to axially lock them together and thereby resist inadvertent axial movement of one relative to the other. The feature 66 illustrated herein is a threaded hole formed half in the outer shroud 14 and half in the inner shroud 18 that is receptive to a threaded rod engagable therewith.

0011Each of the bodies 30 in this embodiment is further configured to sealingly engage with each of the other bodies 30 that are located perimetrically adjacent thereto. Such sealing engagement may be via tortuous paths formed by complementary shapes on each perimetrical side of the bodies 30. For example, each of the bodies 30 may have a square tongue 68 on one side and a square groove 72 on the other (as is illustrated in <figref idref="f0001">Figures 1</figref>, <figref idref="f0002">2</figref> and <figref idref="f0003">3</figref>) such that the tongue 68 slidably engages with the groove 72 when being installed in the outer shroud 14.

0012Referring to <figref idref="f0003">Figure 4</figref>, an alternate tortuous path configuration is illustrated at 76. The tortuous path 76 of this embodiment employs a tongue 80 having a protrusion 82, that slidably engages with a complementary groove 84. It should be noted that other configurations of seal arrangements are contemplated including seals that employ more than one of the tongues 68, 80 and grooves 72, 84 and combinations thereof.

0013Referring to <figref idref="f0004">Figure 5</figref>, alternately the sealing engagement could include a separate seal element 94 configured to be positioned between and sealingly engaged with adjacent bodies 30. In the embodiment shown, each body 30 has a groove 98 on each perimetrical side thereof that is receptive to the seal element 94. Although the seal element 94 and the grooves 98 are shown with rectangular cross sections alternate embodiments could employ elements and groove having any practical cross sectional shape.

0014Referring to <figref idref="f0005">Figures 6 and 7</figref>, an alternate embodiment of a turbine shroud engagement arrangement disclosed herein is illustrated at 110. The engagement arrangement 110 differs from the arrangement 10 in that the primarily axial sliding engagement of a protruding member 134 into a channel 122 includes a non-axial component. That is the sliding engagement of the body 130 as the protruding member 134 enters the channel 122 moves in a non-axial direction in addition to the primarily axial direction. In this embodiment the body 130 moves radially inwardly along dashed lines 136 such that when completely installed the leading end 140 of the protruding member 134 is positioned radially inwardly of the trailing end 144. Still other alternate embodiments could be configured such that bodies include a perimetrical component of movement as they are engaged instead of or in addition to the radial component of movement.

0015While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.