WO2013141944A1

WO2013141944A1 - Formed gas turbine engine shroud

Info

Publication number: WO2013141944A1
Application number: PCT/US2012/072235
Authority: WO
Inventors: Jeffrey P. HENKLE; Andy H. IESALNIEKS; James Lloyd; George F. GRIFFITHS; Graham BURKHOLDER; Kenneth Alan Green; Robert D. RUNNER
Original assignee: Rolls-Royce Corporation; Rolls-Royce Power Engineering Plc
Priority date: 2011-12-30
Filing date: 2012-12-30
Publication date: 2013-09-26

Abstract

An apparatus is disclosed that includes a formed shroud ring configured to be disposed in a gas turbine engine and extending in a circumferential direction about an airfoil member and having an integral first portion and a second portion and a yielded material region between the first portion and the second portion, the first portion bent relative to the second portion to form a bent area, and wherein the yielded material region extends substantially through a thickness of the bent area.

Description

FORMED GAS TURBINE ENGINE SHROUD

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of U.S. Provisional Patent Application 61/581 ,829, filed December 30, 2011 , and is incorporated herein by reference.

TECHNICAL FIELD

The present invention generally relates to gas turbine engine component constructions, and more particularly, but not exclusively, to gas turbine engine shroud components.

BACKGROUND

Providing shroud components capable of use within gas turbine engines remains an area of interest. The shroud ring assemblies employed in current practice are, however, generally complex and expensive to produce. Current shroud rings are typically forged and require extensive machining to produce a final product. This complex processing can result in wasted material and a high initial cost.

Some current shroud components have various shortcomings relative to certain applications. Accordingly, there remains a need for further contributions in this area of technology.

SUMMARY

One embodiment of the present invention is a unique shroud component for use in a gas turbine engine. Other embodiments include apparatuses, systems, devices, hardware, methods, and combinations for constructing gas turbine engine shroud components. Further embodiments, forms, features, aspects, benefits, and advantages of the present application shall become apparent from the description and figures provided herewith.

BRIEF DESCRIPTION OF THE DRAWINGS

The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and wherein:

Fig. 1 depicts an embodiment of a gas turbine engine.

Fig. 2 depicts a view of an embodiment of a formed shroud ring in a compressor section of a gas turbine engine.

Figs. 3A-3C depict one embodiment of a shroud ring in stages of formation. Fig. 4 depicts a view of an embodiment of an axial feature of a formed shroud ring.

Fig. 5 depicts a view of an embodiment of multiple formed shroud rings joined together.

Fig. 6 depicts a view of an embodiment of a formed shroud ring.

Fig. 7 depicts a view of an embodiment of a plurality of formed shroud ring segments which are interconnected.

Fig. 8 depicts a view of an embodiment of a shroud ring formed by a roll forming device.

DETAILED DESCRIPTION OF THE DRAWINGS

For 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, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.

With reference to Fig. 1 , one embodiment is disclosed of a gas turbine engine 100. Many different embodiments are envisioned for the gas turbine engine 100 such as, but not necessarily limited to, turboprop, turboshaft, or turbofan engines. The gas turbine engine 100 of the illustrated embodiment includes a compressor 102 in communication with an inlet air stream 106, a combustor 108, and a turbine 104, and is depicted as a single spool engine, though a greater number of spools are contemplated in other embodiments. The gas turbine engine 100 can be an adaptive cycle and/or variable cycle engine. In some forms the gas turbine engine 100 is capable of providing power to rotate a shaft which can be coupled to a variety of devices such as, but not limited to, a generator.

In some applications, the gas turbine engine 100 can alternatively and/or additionally be used to provide power to an aircraft. As used herein, the term "aircraft" includes, but is not limited to, helicopters, airplanes, unmanned space vehicles, fixed wing vehicles, variable wing vehicles, rotary wing vehicles, unmanned combat aerial vehicles, tailless aircraft, hover crafts, and other airborne and/or extraterrestrial

(spacecraft) vehicles. Further, the present inventions are contemplated for utilization in other applications that may not be coupled with an aircraft such as, for example, industrial applications, power generation, pumping sets, naval propulsion, surface vehicles, weapon systems, security systems, perimeter defense/security systems, and the like known to one of ordinary skill in the art.

Referring generally to Figs. 1-2, the turbomachinery components of the gas turbine engine 100, such as the compressor 102 and the turbine 104, can include a plurality of airfoil members 212 having the form of blades 202 and vanes 214. As utilized herein, blades 202 are turbomachinery components which rotate about a central axis 110 of the gas turbine engine 100 while vanes 214 are fixed relative to the central axis 110. The vanes 214 can be either variable or static in any given embodiment. The gas turbine engine 100 is also depicted as having an engine casing 210. The

embodiment depicted in Fig. 2 illustrates a view of the compressor 102, but it is contemplated that the shroud rings 204 can be disposed within the turbine 104 of the gas turbine engine 00 as well.

Shroud components, such as shroud ring 204, are generally circumferentially extending components radially offset from the airfoil members 2 2 and in some forms can be used to form a flow path surface through the turbomachinery component. In the illustrated embodiment, the shroud ring 204 is shown as being located radially outward of the airfoil members 212. The shroud ring 204 can be used in some forms to retain and/or position the vanes 214 within the working flow path of the turbomachinery component. The shroud ring 204 can also be used to discourage gas leakage from the working fluid flow path of the gas turbine engine 100 into the engine casing 210.

A support structure 208 is used in the illustrated embodiment to retain the shroud rings 204 through flanges 216, but other alternative and/or additional retention techniques are contemplated herein. The support structure 208 can be integral with or mounted directly or indirectly to the engine casing 210 of the gas turbine engine 100. The support structure 208 can include cooling channels, expansion joints, or other devices to reduce the effects of thermal expansion such that the spacing and disposition of the shroud rings 204 relative to the airfoil members 212 can be maintained within a desired range. In some embodiments, the shroud rings 204 may additionally and/or alternatively contain cooling channels or the like. The shroud rings 204 can be supported in any manner such that they are located axially, radially, and/or

circumferentially in relation to a portion of the airfoil members 212.

In the illustrated embodiment, the shroud ring 204 includes a coating 206 which can be used to establish a wear or sealing surface, but not all embodiments of the shroud ring 204 need include a coating 206. In one form, the coating 206 can allow for build-up tolerances between the shroud ring 204 and the blade 202 or vane 214. The coating 206 can be an abradable coating, while in other non-limiting embodiments the coating 206 can take the form of a honeycomb coating, among other coatings. The coating can be applied, bonded, coupled, affixed, attached, sprayed, etc. to the shroud ring 204. To set forth just a few non-limiting examples, the coating 206 can be applied through a thermal spray, various vapor deposition processes, or sintering, among other possible coating application techniques.

The shroud ring 204 is constructed through a forming process that involves manipulating a stock of material through a die or series of dies, the details of which are described in more detail further below. The forming process or processes can yield a net shape or near net shape finished article. Figs. 3A-3C depict one embodiment of stages of formation of the shroud ring 204 from a portion of sheet stock 302. Each of the figures include a line of reference 308 useful in providing orientation for purposes of description. As shown in these embodiments, the shroud ring 204 is symmetrical across the line of reference 308, however, the shroud ring 204 can be of any shape whether or not symmetrical.

Fig. 3A depicts a portion of sheet stock 302 prior to being formed into the shroud ring 204 as depicted in Figs. 3B and 3C. The sheet stock 302 capable of being used with the processes described herein can take a variety of forms. For example, the sheet stock 302 can be any suitable material, including, but not limited to steel, stainless steel, and/or titanium alloys. Such material can have a variety of material

characteristics that can make it useful in various portions of the gas turbine engine. The sheet stock 302 can further be of any height, width, and depth, some of which may provide minimal processing to form a net shape through the metal forming process after completion of the processes depicted in the illustrated embodiment. In some forms the sheet stock 302 can be a planar sheet but other forms are also contemplated such as tubular, single and/or double walled, among other configurations.

As shown in Fig. 3B, a first portion 304 of the sheet stock 302 is bent relative to a second portion 310, such as what can be formed after processing the sheet stock 302 through a die or progressive series of dies. Forcing the sheet stock 302 against the die, imparts a force upon the sheet stock, thereby deforming the sheet stock 302. This deformation results in the formation of the bend and results in a yielded material region 306. While the bend in Fig. 3B is illustrated as a right angle, it is contemplated that the bend can have any angle suitable for the desired application.

At the bend, the sheet stock 302 is substantially yielded throughout a thickness 312 of the sheet stock 302. In one form such substantial yielding provides a greater portion of the sheet stock 302 near the bend that is yielded than remains unyielded. The yielded material region 306 includes a portion that is plastically deformed and can include various residual stresses. The yielded material within region 306 may not include the entire portion of sheet stock 302 which is encircled in Fig. 3B and in some forms may be limited to the area within the bend. The yielded material region 306 can vary in size and shape depending upon the specific application and processing of the material sheet stock 302. The yielded material region 306 can include an outer surface 314 of the bend which includes tensile stresses and can include an inner surface of the bend which includes compressive stresses. The yielded material region 306 may include buckling, waves, or other imperfections which can result from forming, depending upon the forming process utilized. Some of these residual stresses and forming imperfections can be removed or partially removed by post forming processing, including, but not limited to heat treatment or polishing, while other stresses and/or imperfections can remain within the material.

The sheet stock 302 can proceed through another die or series of forming dies to form the near net shape shroud ring 204 as is depicted in Fig. 3C. One or more dies can be utilized to form bends and impart an arcuate shape to form the shroud ring 204 or a segment of the shroud ring 204. The use of progressive dies in forming the shroud ring 204 from the sheet stock 302 can result in less concentrated stress formations within the shroud ring 204 than would be present through the use of a single die.

In some forms the die can include a member capable of rotation. This member of rotation can include a roller, such as a roller that is utilized in a roll forming process. The roller and/or series of rollers are disposed to impart forces upon the sheet stock 302 to impart a desired shape to the shroud ring 204. One or more roll forming machines, each including at least one roller, can be utilized in the formation of the shroud ring 204. One embodiment of a forming die is discussed below in Fig. 8. Though the illustrated embodiment in Figs. 3A-3C depicts three separate illustrations, no limitation is intended regarding whether each figure implies a single step of construction. For example, the end portions of the sheet stock 302 shown in Fig. 3B can be formed in a single construction step but in some embodiments one of the end portions can be formed prior to the other end portions. Thus, multiple portions of the shroud ring 204 can be either serially or simultaneously shaped through one or more dies or series of dies. Furthermore, while a net shape is contemplated in many embodiments, in other embodiments, further processing can be desired. Such further processing can include, but is not limited to, turning, milling, and/or burnishing, among other processes, to obtain the desired shape and finish. In still further embodiments, the shroud ring 204 and/or the sheet stock 302 can be heat treated and/or receive a heat resistant coating, such as through a deposition or sintering process, to satisfy the temperature requirements of a shroud ring 204 in a turbine 104.

Referring to Figs. 4-5, a plurality of shroud rings 204 may be joined to form a shroud ring assembly 500. Adjacent shroud rings 204 may be joined by welding, brazing, or other chemical and/or mechanical fastening processes. One example of this joining is illustrated as a weld 502. The joining of two or more shroud rings 204 allows for the formation of shroud components which could not be achieved solely through forming processes or where it is desirable to join multiple shroud components to produce a single component, rather than solely using a forming process. While only a few differing structures for the shroud ring 204 are illustrated in the figures, other shapes and configurations are also contemplated that can be manufactured through a metal forming process, the joining of a plurality of shroud rings 204, and/or through other processing such as but not limited to post forming machining.

In some embodiments of the shroud rings 204, an axial feature 402 may be formed. The axial feature 402 can accommodate a portion of a turbine hub, a blade tip having an axial protrusion, or any other rotating component which requires an axially disposed shroud ring 204.

As will be appreciated given the discussion herein, the shroud ring 204 can be formed as a single piece. The shroud ring 204 can be formed from a planar portion of sheet stock 302 into an annular shaped component. The circumferential free ends of the shroud ring 204 formed form the planar sheet stock can be mechanically or chemically bonded to form an annular shroud ring 204. In some forms the shroud ring 204 can be formed from a sheet stock 302 that has first been formed into a tube prior to a forming operation through a die or series of dies. In this embodiment, the

circumferential edge may be fed into a die or plurality of dies to form the bends described above.

In still other embodiments, the shroud ring 204 can include one or more individual segments such as the arc like segments depicted in Figs. 6 and 7. Fig. 6 depicts a portion of a single segment of a shroud ring 204. Fig. 7 depicts a plurality of segments 704 which are joined at intersegment seal 702 to form an annular shroud ring 204. As used herein, and unless indicated to the contrary, the term shroud ring or ring is intended to include any annular shroud ring, or annular shroud ring segment that can be coupled with other annular segments to form an annular ring. The segments 704 can be joined through welding, brazing, or through other chemical and/or mechanical processes or fasteners. The intersegment seals 702 can be designed to accommodate thermal expansion of the segments 704 relative to one another. The intersegment seal 702 discourages gas leakage from the shroud ring 204 which is exposed to the fluid flow path of the gas turbine engine 100.

One embodiment of a forming device 806 is illustrated in Fig. 8. The sheet stock 302 is feed into a forming die or plurality of forming dies 802. The die or dies 802 can progressively manipulate the sheet stock 302, thereby forming a plurality of bends as was discussed with reference to Fig. 3B. An arc forming die or dies 804 imparts an arcuate curvature to the sheet stock 302. While Fig. 8 depicts sheet stock 302 being processed by the forming die 802 prior to the arc forming die 804, the arcuate curvature can be imparted prior to any bending of the sheet stock 302.

One aspect of the present application provides an apparatus including a formed shroud ring configured to be disposed in a gas turbine engine and extending in a circumferential direction about an airfoil member and having an integral first portion and a second portion and a yielded material region between the first portion and the second portion, the first portion bent relative to the second portion to form a bent area, and wherein the yielded material region extends substantially through a thickness of the bent area.

One feature of the present application provides wherein the bent area includes a residual tensile stress extending along a portion of an outer surface of the bent area.

Another feature of the present application provides wherein the formed shroud ring is a progressive roll-formed shroud ring.

Yet another feature of the present application provides wherein the formed shroud ring includes a first end coupled to a second end to form an annular shape, and wherein the formed shroud ring is disposed in a turbomachinery component of the gas turbine engine, the turbomachinery component including the airfoil member.

Still yet another feature of the present invention provides wherein the formed shroud ring is symmetrical about a reference and having at least two bent areas on each side of the reference, and wherein the bent area includes a residual compressive stress extending along a portion of an inner surface of the bent area.

Another feature of the present invention provides wherein the formed shroud ring further includes an axial feature capable of receiving a rotating member of a

turbomachinery component.

Yet another feature of the present invention further includes a plurality of formed shroud rings coupled to form an assembly.

Still yet another feature of the present invention provides wherein a first ring portion and a second ring portion of the plurality of roll-formed shroud rings are affixed by a joining process.

Another feature of the present invention further includes the gas turbine engine having a turbomachinery component, wherein the formed shroud ring is located on an outer diameter of a flow path of a turbomachinery component.

Yet another feature of the present invention provides wherein the turbomachinery component further comprises a compressor.

Another aspect of the present application provides a method, including feeding a material sheet stock into a forming device, the material sheet stock having

characteristics suitable for use in a turbomachinery environment of a gas turbine engine, and forming the material sheet stock into a gas turbine engine shroud ring configured to provide a seal for a working flow path of the gas turbine engine, wherein the forming includes bending a first portion of the material sheet stock relative to a second portion of the material sheet stock forming a bent area.

One feature of the present application further includes permanently deforming the material sheet stock to form an arcuate shape along a circumferential direction of the gas turbine engine, configured to be located in proximity to a flow path of the gas turbine engine.

Another feature of the present application further includes forming a second bend portion from the first portion by yielding the material sheet stock in an area intermediate an end of the first portion and a base of the first portion.

Yet another feature of the present application provides wherein bending the first portion of the material sheet stock relative to the second portion further includes plastically deforming the first portion relative to the second portion and imparting a tensile stress on an outer surface of a portion of the bent area.

Still yet another feature of the present application further includes joining a first end and a second end of the gas turbine engine shroud to form an annular component.

Another feature of the present application further includes coupling a first progressively roll-formed gas turbine engine shroud ring to a second progressively roll- formed gas turbine engine shroud ring.

Yet another feature of the present application includes engaging the gas turbine engine shroud ring with an abradable surface.

Still yet another feature of the present application includes disposing the gas turbine engine shroud ring on an outer diameter of a flow path of a turbomachinery component in a compressor.

Another feature of the present application includes operating upon the sheet stock to remove a portion of material to a first thickness.

Yet another feature of the present application provides wherein feeding the material sheet stock into the forming device further includes feeding the material sheet stock into a roll forming device, the roll forming device including at least one rolling die.

Another aspect of the present application provides a method, including feeding a sheet of a turbomachinery material into a roll forming machine, engaging a portion of the sheet of turbomachinery material with a first roll forming member of the roll forming machine to form a first portion of a gas turbine engine shroud component, and delivering a force to the sheet of turbomachinery material by contact with a second roll forming member to form a second portion of the gas turbine engine shroud component.

One feature of the present application provides wherein the engaging includes progressively engaging the portion with a series of first roll forming members.

Another feature of the present application provides wherein the engaging includes deforming the sheet along a circumferential direction.

Yet another feature of the present application provides wherein delivering the force includes forming a first turned region, and which further includes forming a second turned region intermediate the first turned region and an edge of the sheet, the forming accomplished by progressive roll forming.

Still yet another feature of the present application further includes disposing a protective coating on a portion of the shroud component.

Another feature of the present application further includes affixing the gas turbine engine shroud component into a compressor of a gas turbine engine.

While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment(s), but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as permitted under the law. Furthermore it should be understood that while the use of the word preferable, preferably, or preferred in the description above indicates that feature so described may be more desirable, it nonetheless may not be necessary and any embodiment lacking the same may be contemplated as within the scope of the invention, that 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" and "at least a portion" are used, there is no intention to limit the claim to only one item unless specifically stated to the contrary in the claim. Further, when the language "at least a portion" and/or "a portion" is used the item may include a portion and/or the entire item unless specifically stated to the contrary.

Claims

CLAIMS WHAT IS CLAIMED IS:

1. An apparatus, comprising:

a formed shroud ring configured to be disposed in a gas turbine engine and extending in a circumferential direction about an airfoil member and having an integral first portion and a second portion and a yielded material region between the first portion and the second portion, the first portion bent relative to the second portion to form a bent area, and wherein the yielded material region extends substantially through a thickness of the bent area.

2. The apparatus of claim 1 , wherein the bent area includes a residual tensile stress extending along a portion of an outer surface of the bent area.

3. The apparatus of claim 2, wherein the formed shroud ring is a progressive roll-formed shroud ring.

4. The apparatus of claim 2, wherein the formed shroud ring includes a first end coupled to a second end to form an annular shape, and wherein the formed shroud ring is disposed in a turbomachinery component of the gas turbine engine, the turbomachinery component including the airfoil member.

5. The apparatus of claim 4, wherein the formed shroud ring is symmetrical about a reference and having at least two bent areas on each side of the reference, and wherein the bent area includes a residual compressive stress extending along a portion of an inner surface of the bent area.

6. The apparatus of claim 4, wherein the formed shroud ring further includes an axial feature capable of receiving a rotating member of a turbomachinery

component.

7. The apparatus of claim 1 , which further includes the gas turbine engine having a turbomachinery component, wherein the formed shroud ring is located on an outer diameter of a flow path of a turbomachinery component.

8. A method, comprising:

feeding a material sheet stock into a forming device, the material sheet stock having characteristics suitable for use in a turbomachinery environment of a gas turbine engine; and

forming the material sheet stock into a gas turbine engine shroud ring configured to provide a seal for a working flow path of the gas turbine engine, wherein the forming includes bending a first portion of the material sheet stock relative to a second portion of the material sheet stock forming a bent area.

9. The method of claim 8, which further includes permanently deforming the material sheet stock to form an arcuate shape along a circumferential direction of the gas turbine engine, configured to be located in proximity to a flow path of the gas turbine engine.

10. The method of claim 8, which further includes forming a second bend portion from the first portion by yielding the material sheet stock in an area intermediate an end of the first portion and a base of the first portion.

11. The method of claim 8, wherein bending the first portion of the material sheet stock relative to the second portion further includes plastically deforming the first portion relative to the second portion and imparting a tensile stress on an outer surface of a portion of the bent area.

12. The method of claim 9, which further includes joining a first end and a second end of the gas turbine engine shroud to form an annular component.

13. The method of claim 9, which further includes coupling a first

progressively roll-formed gas turbine engine shroud ring to a second progressively roll- formed gas turbine engine shroud ring.

14. The method of claim 9, which further includes engaging the gas turbine engine shroud ring with an abradable surface.

15. The method of claim 8, which further includes operating upon the sheet stock to remove a portion of material to a first thickness.

16. A method, comprising:

feeding a sheet of a turbomachinery material into a roll forming machine; engaging a portion of the sheet of turbomachinery material with a first roll forming member of the roll forming machine to form a first portion of a gas turbine engine shroud component; and

delivering a force to the sheet of turbomachinery material by contact with a second roll forming member to form a second portion of the gas turbine engine shroud component.

17. The method of claim 16, wherein the engaging includes progressively engaging the portion with a series of first roll forming members.

18. The method of claim 17, wherein the engaging includes deforming the sheet along a circumferential direction.

19. The method of claim 18, wherein delivering the force includes forming a first turned region, and which further includes forming a second turned region intermediate the first turned region and an edge of the sheet, the forming accomplished by progressive roll forming.

20. The method of claim 19, which further includes disposing a protective coating on a portion of the shroud component.