Axial retention device for turbine system   

Abstract: An axial retention device for a turbine is disclosed. The axial retention device includes a latch associated with a mating surface of one of a turbine component and a support structure. The latch has an outward bias and includes an axial load surface. The axial retention device further includes a pocket defined in a mating surface of the other of the turbine component and the support structure. The pocket is configured to accept the latch therein and includes a mating axial load surface. Engagement of the latch and the pocket allows the axial load surface and the mating axial load surface to interact, preventing axial movement of the turbine component with respect to the support structure in at least one direction.

FIELD OF THE INVENTION

The subject matter disclosed herein relates generally to turbine systems, and more particularly to axial retention devices for retaining turbine components within turbine systems.

BACKGROUND OF THE INVENTION

Turbine systems are widely utilized in fields such as power generation. For example, a conventional gas turbine system includes a compressor, a combustor, and a turbine. During operation of the gas turbine system, various components in the system are subjected to high temperature flows, which can cause the components to fail. Since higher temperature flows generally result in increased performance, efficiency, and power output of the gas turbine system, the components that are subjected to high temperature flows must be cooled to allow the gas turbine system to operate at increased temperatures. Thus, cooling medium may be flowed through the gas turbine system to cool the various components.

Further, to obtain optimal performance and efficiency of a turbine system, the high temperature flows and cooling medium flows should be generally confined from one another. For example, in the turbine of a turbine system, turbine components are generally provided with cooling medium independent of the high temperature flow to prevent ingestion of the high temperature flow therein during operation. Additionally, sealing devices may be utilized to shield the turbine components from leakage of the high temperature flow, and further to prevent the escape of the cooling medium.

In many cases, the sealing devices and turbine components are mounted in the turbine to annular support structures. The sealing devices and turbine components may further be positioned circumferentially and axially with respect to each other to prevent leakage of the high temperature flow and escape of the cooling medium. However, in many cases, the sealing devices and/or turbine components may shift, slide, or become disengaged with respect to the support structures, thus potentially allowing leakage therein or escape therefrom. This leakage and/or escape can reduce the performance and efficiency of the turbine system, and may further be harmful to the system. Thus, in most cases, the sealing devices and turbine components should not shift, slide, or become disengaged with respect to the support structures.

Thus, an improved retention device for retaining sealing devices and/or turbine components within support structures would be desired in the art. For example, an axial retention device that prevents axial movement of the sealing devices and/or turbine components with respect to the support structures would be advantageous.

Aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.

In one embodiment, an axial retention device for a turbine is disclosed. The axial retention device includes a latch associated with a mating surface of one of a turbine component and a support structure. The latch has an outward bias and includes an axial load surface. The axial retention device further includes a pocket defined in a mating surface of the other of the turbine component and the support structure. The pocket is configured to accept the latch therein and includes a mating axial load surface. Engagement of the latch and the pocket allows the axial load surface and the mating axial load surface to interact, preventing axial movement of the turbine component with respect to the support structure in at least one direction.

These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which:

FIG. 1 is a schematic illustration of a turbine system;

FIG. 2 is a sectional side view of the turbine of a turbine system according to one embodiment of the present disclosure;

FIG. 3 is a sectional side view of a portion of the turbine of a turbine system according to one embodiment of the present disclosure;

FIG. 4 is an exploded perspective view of a support structure and two turbine components according to one embodiment of the present disclosure;

FIG. 5 is a cross-sectional view of an axial retention device according to one embodiment of the present disclosure; and

FIG. 6 is a cross-sectional view of an axial retention device according to another embodiment of the present disclosure.

DETAILED DESCRIPTION

Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.

FIG. 1 is a schematic diagram of a turbine system 10. While the turbine system 10 described herein may generally be a gas turbine system, it should be understood that the turbine system 10 of the present disclosure is not limited to gas turbine systems, and that any suitable turbine system, including but not limited to a steam turbine system, is within the scope and spirit of the present disclosure.

Thus, the system as shown may include a compressor 12, a combustor 14, and a turbine 16. The compressor 12 and turbine 16 may be coupled by a shaft 18. The shaft 18 may be a single shaft or a plurality of shaft segments coupled together to form shaft 18.

The turbine 16 may include a plurality of turbine stages. For example, in one embodiment, the turbine 16 may have three stages, as shown in FIG. 2. For example, a first stage of the turbine 16 may include a plurality of circumferentially spaced nozzles 21 and buckets 22. The nozzles 21 may be disposed and fixed circumferentially about the shaft 18. The buckets 22 may be disposed circumferentially about the shaft 18 and coupled to the shaft 18. A second stage of the turbine 16 may include a plurality of circumferentially spaced nozzles 23 and buckets 24. The nozzles 23 may be disposed and fixed circumferentially about the shaft 18. The buckets 24 may be disposed circumferentially about the shaft 18 and coupled to the shaft 18. A third stage of the turbine 16 may include a plurality of circumferentially spaced nozzles 25 and buckets 26. The nozzles 25 may be disposed and fixed circumferentially about the shaft 18. The buckets 26 may be disposed circumferentially about the shaft 18 and coupled to the shaft 18. The various stages of the turbine 16 may be disposed in the turbine 16 in the path of hot gas flow 28. It should be understood that the turbine 16 is not limited to three stages, but may have any suitable number of stages.

As shown in FIGS. 3 and 4, a plurality of annularly disposed sealing devices 30 may be provided between each plurality of buckets, such as, for example, buckets 22 or 24, and the adjacent plurality of buckets, such as, for example, buckets 24 or 26. The sealing devices 30 may be provided to form an outer boundary for the path of gas flow 28, thus preventing the gas flow 28 from migrating through the outer boundary and further preventing cooling flows (not shown) exterior to the path of gas flow 28 from migrating through the outer boundary into the path. The sealing devices 30 may further interact with the plurality of nozzles, such as nozzles 21, 23, or 25, as shown in FIG. 3. It should be understood that the sealing devices 30 need not be designed as shown in FIGS. 3 and 4, but rather that any suitable sealing device is within the scope and spirit of the present disclosure.

The buckets 22, 24, 26 and sealing devices 30 must be retained in the turbine 16. Thus, various support structures 32 may be provided in the turbine 16 for mating with and supporting various turbine components 34, such as the sealing devices 30 and/or buckets 22, 24, 26. The support structures 32 may be, for example, rotor disks 36 configured to mate with the buckets 22, 24, 26. Alternatively, the support structures 32 may be, for example, spacer rim structures 38 configured to mate with the sealing devices 32.

As shown, the turbine components 34 and support structures 32 may include mating appendages 40 and cavities 42 for mating the turbine components 34 and support structures 32 together. For example, in some embodiments, the appendages 40 may be dovetails, and the cavities 42 may be shaped and sized to receive the dovetails therein. In general, the turbine components 34 are mated to the support structures 32 by sliding the appendages 40 into the cavities 42 along a generally axial axis 44, as shown in FIG. 4. Mating of the appendages 40 in the cavities 42 prevents movement of the turbine components 34 with respect to the support structures 32 in the generally radial and tangential directions, but may not prevent movement of the turbine components 34 with respect to the support structures 32 in a generally axial direction. For example, when the appendages 40 are mated with the cavities 42, the appendages are free to move along the axial axis 44 in a first direction 46 or a second direction 48.

Thus as shown in FIGS. 4 through 6, an axial retention device 50 is provided for axially retaining a turbine component 34 in a support structure 32. The axial retention device 50 includes a latch 52 and a pocket 54. In general, the latch 52 may be associated with one of the turbine component 34 and the support structure 32, and the pocket 54 may be defined in the other of the turbine component 34 and the support structure 32. For example, in exemplary embodiments, the latch 52 may be associated with the support structure 32 and the pocket 54 may be defined in the turbine component 34. In alternative embodiments, the latch 52 may be associated with the turbine component 34 and the pocket 54 may be defined in the support structure 32.

Further, as discussed above, a plurality of turbine components 34 may be disposed in an annular array about the support structure 32. In some embodiments, each turbine component 34 may include an independent latch 52 or define an independent pocket 54 configured to mate with an independent latch 52 or independent pocket 54 included or defined in the support structure 32. In other embodiments, however, as shown in FIG. 4, two adjacent turbine components 34 may each include an independent latch 52 or define an independent pocket 54, and both latches 52 or pockets 54 may be configured to mate with one latch 52 or pocket 54 included or defined in the support structure 32.

The turbine component 34 may define a mating surface 56, and the support structure 32 may define a mating surface 58. The mating surfaces 56, 58 may be defined on the appendage 40 and in the cavity 42, or may be defined adjacent the appendage 40 and cavity 42, as shown in FIGS. 5 through 6. The mating surfaces 56, 58, generally mate together when the turbine component 34 and support structure 32 are mated together. The latch 52 may be associated with the mating surface 56 or 58 of the turbine component 34 or support structure 32, and the pocket 54 may be defined in the other of the mating surface 56 or 58 of the turbine component 34 or support structure 32.

The pocket 54 according to the present disclosure may be configured to accept the latch 52 therein. For example, the pocket 54 may be sized and shaped to accommodate at least a portion of the latch 52 therein, and may further have various features for engaging and interacting with the latch 52, as discussed below.

The latch 52 according to the present disclosure may have a generally outward bias. “Outward” refers to a direction generally radially away from an associated base component or surface, such as a turbine component 34 or support structure 32. For example, in some exemplary embodiments, as shown in FIG. 5, the latch 52 may be pivotal about a pivot point 60. Thus, the latch 52 may be outwardly biased about the pivot point 60. In other exemplary embodiments, as shown in FIG. 6, the latch 52 may simply have a generally radial outward bias.

Further, in some exemplary embodiments, the axial retention device 50 may include a spring 62, or a plurality of springs 62. The springs 62 may provide the outward bias. In embodiments wherein the latch 52 has a pivot point 60, the springs 62 may be located, for example, at the pivot point 60 or spaced from the pivot point 60. It should be understood, however, that the outward bias need not be provided by springs, and rather that the outward bias may be provided by any suitable biasing, tensioning, or preloading device.

In exemplary embodiments, as shown in FIGS. 5 through 6, the mating surface 56 or 58 of the turbine component 34 or support structure 32 that is associated with the latch 52 may define a cavity 64 therein. The latch 52 may be mounted in the cavity 64. Thus, in exemplary embodiments, when the latch 52 is biased outward, a portion of the latch 52 may protrude from the mating surface 56 or 58. Further, in exemplary embodiments, when the latch 52 is retracted, as discussed below, the uppermost portions of the latch 52 may be at or below the mating surface 56 or 58. In alternative embodiments, however, the uppermost portions of the latch 52 may remain above the mating surface 56 or 58 when retracted. The cavity 64 may further include side surfaces 66. The side surfaces 66 may interact with contact points 68 on the latch 52 to prevent movement of the latch 52 along the axial axis 44.

As shown, the latch 52 may include an axial load surface 70, and the pocket 54 may include a mating axial load surface 72. As shown in FIGS. 5 and 6, for example, the axial load surfaces 70, 72 may be generally planer side surfaces of the latch 52 and pocket 54, which may be generally perpendicular to the axial axis 44. It should be understood, however, that the axial load surfaces 70, 72 may have any suitable contours and/or orientations. In general, engagement of the latch 52 and the pocket 54 may allow the axial load surfaces 70, 72 to interact, preventing axial movement of the turbine component 34 with respect to the support structure 32 in at least one direction. For example, interaction of the axial load surfaces 70, 72 may prevent axial movement of the turbine component 34 in the first direction 46, as shown in FIGS. 5 and 6, or in the second direction 48.

In some embodiments, as shown in FIG. 5, the axial retention device 50 may further include a stop 74 associated with one of the turbine component 34 or the support structure 32. The stop 74 may be configured to interact with the other of the turbine component 34 or the support structure 32, preventing axial movement of the turbine component 34 with respect to the support structure in another direction, such that axial movement is prevented in two directions. For example, the stop 74 may have a generally planer side surface, which may be generally perpendicular to the axial axis 44. It should be understood, however, that the stop 74 may have any suitable contour and/or orientation. In general, engagement of the latch 52 and the pocket 54 may allow the stop to interact with a side surface of the other of the turbine component 34 or the support structure 32, preventing axial movement of the turbine component 34 with respect to the support structure 32 in at least one direction. For example, interaction of the stop 74 with the other of the turbine component 34 or the support structure 32 may prevent axial movement of the turbine component 34 in the second direction 48, as shown in FIG. 5, or in the first direction 46.

In another embodiment, as shown in FIG. 6, the latch 52 may include a plurality of axial load surfaces 70, and the pocket 54 may include a plurality of mating axial load surfaces 72. In general, engagement of the latch 52 and the pocket 54 may allow the axial load surfaces 70, 72 to interact, preventing axial movement of the turbine component 34 with respect to the support structure 32 in two directions. For example, interaction of the axial load surfaces 70, 72 may prevent axial movement of the turbine component 34 in both the first direction 46 and the second direction 48, as shown in FIG. 6.

In some embodiments, as shown in FIGS. 4 through 6, the one of the turbine component 34 and the support structure 32 not including the latch 52 may define an access hole 76. The access hole 76 may provide access to the latch 52 for releasing the latch 52 from the pocket 54, allowing axial movement of the turbine component 34 with respect to the support structure 32 in the at least one direction, such as in the first direction 46 or the second direction 48. For example, the access hole 76 may provide access for enabling retraction of the latch 52 from the pocket 54, thus disengaging the axial load surfaces 70, 72. In one embodiment, the access hole 76 may allow a tool, such as a rod, or, for example, an appendage, to be placed through the access hole 76 to interact with the latch 52, to cause retraction of the latch 52.

Further, in some embodiments as shown in FIGS. 5 and 6, the latch 52 may include a sealing surface 78. The sealing surface 78 may be configured to seal the access hole 76 when the latch 52 and pocket 54 are engaged. For example, the sealing surface 78 may be generally parallel to the opening of the access hole 76 adjacent the latch 52 and/or perpendicular to the central axis of the access hole 76. It should be understood, however, that the sealing surface 78 may have any suitable contour and/or orientation sufficient to seal the access hole 76 when the latch 52 and pocket 54 are engaged. When the latch 52 and pocket 54 are engaged, the sealing surface 78 may abut the opening of the access hole 76 that is adjacent the latch 52, thus generally sealing the access hole 76. The sealing surface 78 may beneficially prevent or reduce the potential leakage of high temperature flow and/or escape of cooling medium through the access hole 76 between the turbine component 34 and support structure 32.

Beneficially, the axial retention device 50 of the present disclosure may prevent axial movement of turbine components 34 with respect to support structures 32 in one or more directions. This prevention of axial movement may advantageously prevent or reduce the potential leakage of high temperature flow and/or escape of cooling medium between the turbine component 34 and support structure 32.

This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.