Stator equipment for gas turbine engines

Abstract

A turbine stator apparatus comprises: a compressor housing including a housing wall defining an arcuate flow path surface and an opposing backside surface, the flow path surface defining at least two spaced-apart rotor decks; a row of stator vanes disposed within the compressor housing; wherein the housing wall includes at least one hollow structure; and wherein the housing wall is a single monolithic entity, wherein the stator vanes are integrally formed as part of the monolithic entity.

Description

Technical Field

[0001] The present invention relates generally to gas turbine engines and, more particularly, to stator structures for such engines. Background Art

[0002] A gas turbine engine includes a compressor, a combustor and a turbine in series flow communication. The turbine is mechanically coupled to the compressor, and these three components define a turbine core. The core is operable in a known manner to produce a flow of hot, pressurized combustion gases to operate the engine and perform useful work, such as providing propulsive thrust or mechanical work.

[0003] Typically, the compressor has multiple stages and each subsequent stage has a higher static pressure than the upstream stage, with the last stage discharging air at a desired compressor discharge pressure ("CDP").

[0004] The compressor includes a rotor that rotates within a stator structure including a casing and stator vanes that define a flow path through the rotor.

[0005] A stator structure having a simple construction without many separate components is desired. The connection features required for complex assemblies limit the ability to optimize the design as it relates to controlling rotor airfoil tip clearance, engine axial length, and effectively extracting bleed air from the main flow path for other uses. Summary of the invention

[0006] This needs to be addressed by a stator structure that integrates one or more features with the compressor housing.

[0007] According to one aspect of the technology described herein, a turbine stator apparatus includes a compressor housing including a housing wall defining an arcuate flow path surface and an opposing backside surface, the flow path surface defining at least two spaced-apart rotor lands; a row of stator blades disposed within the compressor housing; wherein the housing wall includes at least one hollow structure; and wherein the housing wall is a single monolithic integral body.

[0008] According to another aspect of the technology described herein, a gas turbine engine apparatus includes: a compressor, a combustor, and a turbine arranged in a series flow relationship, wherein the compressor includes: a compressor casing including a casing wall defining an arcuate flow path surface and a relative backside surface, the flow path surface defining at least two spaced-apart rotor decks; wherein the casing wall includes at least one hollow structure; and wherein the casing wall is a single integral unitary body; at least one row of stator blades disposed within the compressor casing; and at least one row of rotor blades mounted to rotate about a centerline axis within the compressor casing and mechanically coupled to the turbine. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The invention may be best understood by reference to the following description taken in conjunction with the accompanying drawings, in which:

[0010] Figure 1 is a schematic cross-sectional view of a gas turbine engine incorporating an integral stator structure;

[0011] Figure 2 yes Figure 1 A schematic half-section view of a portion of a compressor of an engine of;

[0012] Figure 3 yes Figure 2 A view of the stator structure after removing the rotor is shown;

[0013] Figure 4 yes Figure 3 a front view of a portion of the stator structure shown;

[0014] Figure 5 yes Figure 3 an enlarged view of a portion of; and

[0015] Figure 6 yes Figure 3 An enlarged view of a portion of. DETAILED DESCRIPTION

[0016] Referring to the drawings, wherein like reference numerals refer to like elements throughout the various views, Figure 1 An exemplary gas turbine engine 10 is depicted. Although the example shown is a high bypass turbofan engine, the principles of the present invention are also applicable to other types of engines, such as low bypass turbofans, turbojets, turboprops, etc., and turbine engines with any number of compressor-turbine spools. The principles of the present invention are also potentially applicable to other types of turbomachines, such as power generation turbines or compressors driven by separate prime movers.

[0017] The engine 10 has a longitudinal centerline or axis 11. Note that as used herein, the terms "axial" and "longitudinal" refer to directions parallel to the centerline axis 11, while "radial" refers to directions perpendicular to the axial direction, and "tangential" or "circumferential" refers to directions perpendicular to the axial direction and the radial direction. As used herein, the terms "front" or "front" refer to a position relatively upstream in the airflow through or around a component, while the terms "rear" or "rearward" refer to a position relatively downstream in the airflow through or around a component. The direction of the flow is determined by Figure 1 These directional terms are used for convenience of description only and do not require a particular orientation of the structures described thereby.

[0018] The engine 10 has a fan 14, a supercharger 16, a high pressure compressor or "HPC" 18, a combustor 20, a high pressure turbine or "HPT" 22, and a low pressure turbine or "LPT" 24 arranged in a series flow relationship. In operation, pressurized air from an outlet 26 of the compressor 18 is mixed with fuel and ignited in the combustor 20, thereby producing combustion gases. Some work is extracted from these gases by the high pressure turbine 22, which drives the compressor 18 via an outer shaft 28. The combustion gases then flow into the low pressure turbine 24, which drives the fan 14 and the supercharger 16 via an inner shaft 29.

[0019] Figure 2 is a half-section view of a portion of a HPC 18 incorporating an exemplary embodiment of a stator structure. The HPC 18 is used as an example to illustrate the principles of the present invention. The illustrated stage-by-stage features are intended to show a portion of the range of design approaches enabled by the present invention. Different approaches and different materials, such as different metal alloys, may be used in different locations, such as different stages of a compressor within the same axially integral structure.

[0020] HPC 18 includes a compressor rotor 30 that is rotatable about centerline axis 11 and mechanically coupled to the above-mentioned outer shaft 28. The rotor includes a plurality of stages. Each stage includes a row of circumferentially spaced airfoil-shaped rotor blades 32. For example, a typical compressor may include 6-14 stages. In operation, each subsequent compressor stage gradually increases the static air pressure, and the last stage discharges air at a desired compressor discharge pressure ("CDP") for subsequent flow into combustor 20 ( Figure 1 ).

[0021] The compressor 18 is surrounded by a compressor housing 34 which supports stator vanes 52 as described below. The compressor housing 34 includes a housing wall 36 having an arcuate radially inner side surface 38 (also referred to as a flow path surface) and an opposing radially outer side surface 40.

[0022] refer to Figure 3 , the flow path surface 38 defines two or more rotor lands 42, which are arcuate surfaces shaped and sized to closely surround the tips of the rotor blades 32. One rotor land 42 is positioned outside each row of rotor blades 32.

[0023] In the example shown, a single compressor housing 34 is provided, which may extend over the entire length of the compressor. In this example, seven rotor blade rows are shown. It will be appreciated that the compressor housing may alternatively be constructed as two or more sections arranged in series in the axial direction. For example, the compressor housing may include a front section and a rear section that will be joined together by bolted joints or other similar arrangements. For the purposes of the present invention, each of these sections will constitute a "compressor housing."

[0024] When assembled in the engine 10, the compressor housing 34 is generally annular so that the flow path surface 38 can be a body of revolution. In one exemplary configuration, the housing wall 36 can be a single unitary, unitary or monolithic annular structure that defines the flow path surface 38. Alternatively, the compressor housing 34 can be divided along one or more axial-radial planes to define segments that can be connected together. For example, Figure 4 The compressor housing 34 is shown divided into a left section 44 and a right section 46, with the left sections 44, 46 each including an arcuate housing wall 36. Each of the sections 44, 46 includes a split line flange 48 that abuts one another. The split line flanges 48 are clamped together by conventional fasteners 50. Although two sections are shown, it should be understood that the compressor housing 34 can be divided into any number of sections. It will be further understood that the split line flange 48 can be located at any clock position relative to the compressor housing 34.

[0025] Each housing wall 36 may be a single unitary, one-piece, or monolithic component. The housing wall 36 may be manufactured using a manufacturing process involving layer-by-layer construction or additive manufacturing (as opposed to material removal in a conventional machining process). Such processes may be referred to as "rapid manufacturing processes" and / or "additive manufacturing processes," the term "additive manufacturing process" being a term generally referring to such processes herein. Additive manufacturing processes include, but are not limited to, direct metal laser melting (DMLM), laser net shaping manufacturing (LNSM), electron beam sintering, selective laser sintering (SLS), 3D printing, such as by inkjet and laser jetting, stereolithography (SLA), electron beam melting (EBM), laser engineered net shaping (LENS), and direct metal deposition (DMD). Optionally, a unitary, one-piece, or monolithic structure may be manufactured from more than one material or more than one metal alloy using an additive manufacturing process.

[0026] The compressor casing 34 supports a plurality of circumferentially spaced stator rows of fixed airfoil-type stator vanes 52. The stator vanes 52 of each stator vane row extend inwardly from the flow path surface 38. Typically, one stator row is positioned immediately downstream of each blade row.

[0027] Some or all of the stator vanes 52 may be formed as part of the housing wall 36 as a single unitary, one-piece, or monolithic component. Figure 3 . The stator vanes 52 may have uniform vane-to-vane spacing around the circumference of the compressor housing 34, or the vane-to-vane spacing may be non-uniform. Non-uniform spacing is advantageous because a unitary, one-piece, or monolithic construction avoids practical limitations on non-uniform spacing when using individual vanes, such as increasing the number of unique parts or the risk of assembly errors.

[0028] The compressor housing 34 includes one or more annular, radially extending flanges. An example flange is Figure 3 Reference is made to the reference numeral 54. The flange is used for purposes such as structural reinforcement, providing thermal mass and / or providing mechanical attachment.

[0029] Each housing wall 36 may include one or more structures as part of a single integral body, the function of which is to enhance the performance of the compressor housing 34, such as by reducing its weight, improving its thermal response characteristics, reducing its number of parts, and / or improving bleed air extraction efficiency. These structures collectively have at least one portion protruding from the surrounding area of ​​the outer side surface 40 of the housing wall 36, and at least one hollow cavity formed in the housing wall 36. These may generally be referred to herein as "hollow structures".

[0030] The compressor housing 34 may include one or more thermal shields. Generally, a thermal shield is a thin structure that defines a barrier or housing that surrounds a portion of another structure and is separated from the associated structure.

[0031] In the example shown, the compressor housing 34 includes a heat shield 56 surrounding the flange 54. The heat shield 56 is an arcuate or annular structure (it can be a segmented annulus). It has a relatively small wall thickness, generally substantially less than the average wall thickness "T1" of the housing wall 36. Its shape is generally "U" or "V" shaped, with radial legs 58 connected by axial legs 60 (viewed from a half-section). The inner ends of the radial legs 58 are connected to the rest of the housing wall 36 at an integral connection. The heat shield 56 at least partially surrounds the associated flange 54 and generally conforms to the cross-sectional shape of the flange 54. Therefore, both the flange 54 and the surrounding heat shield 56 can be described as "protruding" from the surrounding portion of the outer side surface 40 of the housing wall 36. A hollow chamber 62 is defined between the flange 54 and the heat shield 56 and serves as an insulating gap. Optionally, a hollow chamber (not shown) can be defined within the flange 54.

[0032] Each heat shield 56 is an example of a “hollow structure” as the term is used herein.

[0033] The compressor casing 34 may include one or more flexible tip shroud assemblies 64. Figure 5A portion of the housing wall 36 adjacent the flow path side 38 is formed as an arcuate shroud 66 having a flow path side 68 and a back side 70, the flow path side 68 being configured to closely surround the rotor blade 32. A pair of spaced apart flanges 72 protrude from the outer side 40 of the housing wall 36. They may optionally be surrounded by a heat shield 74 similar to the heat shield 56 described above. The number of flanges may optionally be one or more than two.

[0034] The back side 70 of the shield 66 is connected to the flange 72 and / or the surrounding portion of the housing wall 36 by one or more ligaments or beams 76 that act as elastic spring elements. This means that their shape, size, material composition and position allow them to deflect under an applied load and then return to a nominal position. It should be understood that other geometric shapes can be used as spring elements. The ligament 76 connects the central portion of the back side 70 of the shield 66 at a relatively elongated neck 78, and the front and rear sides of the neck 78 are grooves 80.

[0035] In operation, the shroud 66 can move, pivot, and / or translate in one or more directions in response to an applied load (e.g., contact of the compressor blade tips, commonly referred to as "wipe"). For example, it can move radially outward and / or pivot into one or both of the grooves 80. After the applied load is removed, the shroud 66 returns to the nominal position by the restoring force from the beam 76. This characteristic is referred to as the shroud 66 being "flexible." The shroud 66, flange 72, and ligament 76 together define a flexible tip shroud assembly 64. The flexible tip shroud assembly 64 is an example of a "hollow structure" as the term is used herein.

[0036] Return to reference Figure 3 , the compressor housing 34 may include a bleed slot 82 through the thickness of the housing wall 36. The bleed slot 82 may extend over the entire circumference or a portion of the circumference of the compressor housing 34. In the example shown, the single bleed slot 82 is a full 360° slot. The bleed slot 82 defines an inlet 84 at the flow path surface 38.

[0037] During engine operation, a portion of compressed air from the main flow path 86 of the engine 10 enters the bleed slot 82 through the inlet 84 and enters a discharge chamber 88 defined in part by an annular outer wall 90 (e.g., a portion of a manifold or outer casing) surrounding the compressor housing 34. The air entering the discharge chamber 88 may be redirected or routed as desired for various end uses via appropriate conduits, valves, etc. (not shown).

[0038] The bleed slot 82 extends along a slot axis 92 that is disposed at an angle θ that is non-parallel and non-perpendicular to the centerline axis 11 of the engine 10. More specifically, the angle θ may be selected to reduce pressure losses by passing the bleed air through a relatively low angle. As used herein, the term "low angle" refers to an angle of about 65° or less. For example, the angle θ may be in the range of about 30° to about 65°. In the illustrated example, the angle θ is about 37°.

[0039] In the example shown, a circumferential array of structural struts 94 are disposed within the bleed slot 82 with spaces therebetween. By appropriately selecting their thickness, the struts 94 function to improve the structural rigidity of the compressor housing 34, control the passage width between opposing passage surfaces, and may also control the throat area of ​​the bleed slot 82. In addition to the low-angle orientation described above, the performance of the bleed slot 82 may be further improved by shaping and orienting the struts 94 so that they function as turning vanes, i.e., reducing the tangential velocity (or tangential velocity component) of the flow, also known as "de-swirl" of the flow.

[0040] The vent groove 82 is an example of a "hollow structure" as the term is used herein.

[0041] The compressor housing 34 may include one or more hollow flanges. In the example shown, a portion of the housing wall 36 adjacent the flow path side 38 protrudes from the outer side surface 40 to define a hollow flange 96 including a hollow interior cavity 98. Figure 6 As shown, the internal chamber 98 includes a lattice structure 100. The lattice structure 100 may include a plurality of internal beams 102. In the example shown, the beams 102 are arranged in a grid pattern of intersecting parallel rows. The configuration of the beams 102 can be customized to suit a particular application. This means that their shape, size, material composition, and position can be selected to produce specific mechanical and / or thermal properties. For example, the appropriate configuration of the beams 102 can result in the hollow flange 96 having a lower effective thermal expansion coefficient than a beam made of solid material with the same material composition and cross-sectional shape.

[0042] Hollow flange 96 is an example of a "hollow structure" as that term is used herein.

[0043] The stator structure described herein has advantages over the prior art. It can provide specific fuel consumption ("SFC") benefits by enabling reduced clearances and the potential to move the emission stage forward. It can reduce costs by reducing the number of parts and assembly labor. Integrating the stator vanes into the housing can take a more tailored approach to uneven vane spacing, thereby bringing aeromechanical advantages to adjacent rotor stages, thereby allowing the use of more aerodynamic rotor airfoil geometries to reduce fuel consumption. This integration can reduce engine weight by eliminating the redundancy of the external flow path of the fixed stator vanes and the retention features associated with the separable stator vanes, reducing the engine length required to package these retention features, and reducing the total number of fasteners by reducing the number of circumferential bolt connections and the integration of the heat shield.

[0044] Combining integrated design with additive manufacturing increases the ability to employ clearance control features that are tailored to the unique combination of case and rotor growth. Using additive methods to manufacture the stator structure will also allow for tighter exhaust throats or the addition of exhaust vanes with more aerodynamic diffusion than with conventional methods, rather than simple struts between the inner and outer flow surfaces. It can achieve this more efficient exhaust geometry in a shorter engine axial length and integrate the exhaust geometry into the thermal control structure more effectively than with conventional manufacturing methods to achieve tip clearance matching. In summary, sufficient secondary air bleed static pressure increase can allow bleed air to be extracted from earlier compressor stages, thereby reducing engine fuel consumption overall. The use of additive manufacturing allows flexible tip shrouds to be integrated into the casing to reduce air leakage, reduce flow path geometry tolerance stack-up (tighter clearances) and avoid wear at the separable interface with the casing.

[0045] A stator structure for a gas turbine engine has been described above. All features disclosed in this specification (including any accompanying claims, abstract and drawings) and / or all steps of any method or process disclosed herein may be combined in any combination, unless at least some of such features and / or steps in the combination are mutually exclusive.

[0046] Unless expressly stated otherwise, each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose. Therefore, unless expressly stated otherwise, each feature disclosed is only an example of a general series of equivalent or similar features.

[0047] The invention is not limited to the details of the foregoing embodiments. The invention extends to any novel one or any novel combination of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or any novel one or any novel combination of the steps of any method or process so disclosed.

[0048] Further aspects of the invention are provided by the subject matter of the following numbered clauses:

[0049] 1. A turbine stator arrangement comprising: a compressor housing including a housing wall defining an arcuate flow path surface and an opposed backside surface, the flow path surface defining at least two spaced-apart rotor platforms; a stator blade row disposed within the compressor housing; wherein the housing wall includes at least one hollow structure; and wherein the housing wall is a single monolithic unitary body, wherein the stator blade unitary body is formed as a part of the monolithic unitary body.

[0050] 2. Apparatus according to any of the preceding clauses, wherein the compressor housing comprises a plurality of housing walls connected together to define a full annular structure.

[0051] 3. A device according to any of the preceding clauses, wherein the housing wall is a fully annular structure.

[0052] 4. A device according to any of the preceding clauses, wherein the compressor housing comprises different materials at different locations.

[0053] 5. A device according to any of the preceding clauses, wherein the shell wall comprises: a venting groove passing through the shell wall, the venting groove having an inlet, the venting groove extending along the axis of the narrow slot; and a row of pillars are arranged in the venting groove, wherein the venting groove is integrally formed as part of a monolithic whole.

[0054] 6. A device according to any of the preceding clauses, wherein the slot axis is arranged at an angle of approximately 65° or less relative to the centerline axis of the housing wall.

[0055] 7. The device according to any of the preceding clauses, wherein the housing wall comprises a flexible tip shroud, wherein said flexible tip shroud is integrally formed as part of a unitary body.

[0056] 8. The device according to any of the preceding clauses, wherein the housing wall comprises a heat shield, wherein the heat shield is integrally formed as part of a one-piece body.

[0057] 9. The device according to any of the preceding clauses, wherein the housing wall comprises an annular hollow flange having an internal lattice structure, wherein the hollow flange is integrally formed as part of a monolithic body.

[0058] 10. Apparatus according to any preceding clause, wherein the stator blades have uneven spacing around the circumference of the housing.

[0059] 11. A gas turbine engine device, comprising: a compressor, a combustor and a turbine arranged in a serial flow relationship, wherein the compressor comprises: a compressor casing, the compressor casing comprising a casing wall defining an arcuate flow path surface and an opposing back side, the flow path surface defining at least two spaced-apart rotor decks; wherein the casing wall comprises at least one hollow structure; and wherein the casing wall is a single monolithic entity; at least one row of stationary blades disposed in the compressor casing, wherein the stationary blades are integrally formed as part of the monolithic entity; and at least one row of rotor blades mounted to rotate about a centerline axis within the compressor casing and mechanically connected to the turbine.

[0060] 12. Apparatus according to any of the preceding clauses, wherein the compressor housing comprises a plurality of housing walls connected together to define a full annular structure.

[0061] 13. A device according to any of the preceding clauses, wherein the housing wall is a fully annular structure.

[0062] 14. Apparatus according to any of the preceding clauses, wherein the compressor housing comprises different materials at different locations.

[0063] 15. A device according to any of the preceding clauses, wherein the shell wall comprises: a venting groove passing through the shell wall, the venting groove having an inlet, the venting groove extending along the axis of the narrow slot; and a row of pillars are arranged in the venting groove, wherein the venting groove is integrally formed as part of the integral whole.

[0064] 16. A device according to any of the preceding clauses, wherein the slot axis is arranged at an angle of approximately 65° or less relative to the centreline axis of the housing wall.

[0065] 17. The device according to any of the preceding clauses, wherein the housing wall comprises a flexible tip shroud, wherein the flexible tip shroud is integrally formed as part of a unitary body.

[0066] 18. The device according to any of the preceding clauses, wherein the housing wall comprises a heat shield, wherein said heat shield is integrally formed as part of a one-piece body.

[0067] 19. The device according to any of the preceding clauses, wherein the housing wall comprises an annular hollow flange having an internal lattice structure, wherein the hollow flange is integrally formed as part of a monolithic body.

[0068] 20. Apparatus according to any preceding clause, wherein the stator blades have uneven spacing around the circumference of the housing.

Claims

1. A turbine stator device, characterized in that: include: a compressor housing including a housing wall defining an arcuate flow path surface and an opposed backside surface, the flow path surface defining at least two spaced-apart rotor lands; and a row of stator blades, the row of stator blades being disposed within the compressor housing; wherein the housing wall comprises a flexible tip shroud located outside the rotor deck immediately upstream or downstream of the row of stator blades; and wherein a) the housing wall includes the flexible tip shroud, and b) the stator blades form a single monolithic entity; wherein the flexible tip cover comprises a cover portion having an elongated neck connecting the cover portion to at least two beams, the at least two beams being configured as elastic spring elements; The at least two beams are further connected to i) a pair of spaced apart flanges protruding from an outer side of the housing wall, and ii) the housing wall.

2. The device according to claim 1, characterized in that The compressor housing includes a plurality of housing walls joined together to define a full annular structure.

3. The device according to claim 1, characterized in that The housing wall is a full annular structure.

4. The device according to claim 1, characterized in that The compressor housing comprises different materials at different locations.

5. The device according to claim 1, characterized in that The housing wall comprises: A venting groove, the venting groove passes through the shell wall, the venting groove has an inlet, and the venting groove extends along a groove axis; and An array of struts is disposed in the venting slot, wherein the venting slot is integrally formed as part of the monolithic body.

6. The device according to claim 5, characterized in that in, The slot axis is disposed at an angle of approximately 65° or less relative to a centerline axis of the housing wall.

7. The device according to claim 1, characterized in that Wherein the housing wall comprises a flexible tip shroud, wherein the flexible tip shroud is integrally formed as part of the monolithic body.

8. The device according to claim 1, characterized in that Wherein the housing wall comprises a heat shield, wherein the heat shield is integrally formed as part of the one-piece body.

9. The device according to claim 1, characterized in that Wherein the housing wall comprises an annular hollow flange having an internal lattice structure, wherein the hollow flange is integrally formed as part of the monolithic body.

10. The device according to claim 1, characterized in that The stator vanes have uneven spacing around the circumference of the housing.

11. A gas turbine engine device, characterized in that: include: A compressor, a combustor, and a turbine arranged in series flow relationship, wherein the compressor comprises: a compressor housing including a housing wall defining an arcuate flow path surface and an opposed backside surface, the flow path surface defining at least two spaced-apart rotor lands; wherein the housing wall comprises a flexible tip shield; and wherein said housing wall including said flexible tip shield forms a single monolithic integral body; at least one row of stator vanes disposed within the compressor housing, wherein the stator vanes are integrally formed as part of the monolithic body; and at least one row of rotor blades mounted for rotation about a centerline axis within the compressor casing and mechanically coupled to the turbine; wherein the flexible tip cover comprises a cover portion having an elongated neck connecting the cover portion to at least two beams, the beams being configured as elastic spring elements; The at least two beams are further connected to i) a pair of spaced apart flanges protruding from an outer side of the housing wall, and ii) the housing wall.

12. The device according to claim 11, characterized in that in, The compressor housing includes a plurality of said housing walls joined together to define a full annular structure.

13. The device according to claim 11, characterized in that The housing wall is a full annular structure.

14. The device according to claim 10, characterized in that The compressor housing comprises different materials at different locations.

15. The device according to claim 11, characterized in that The housing wall comprises: A venting groove, the venting groove passes through the shell wall, the venting groove has an inlet, and the venting groove extends along a groove axis; and An array of struts is disposed in the venting slot, wherein the venting slot is integrally formed as part of the monolithic body.

16. The device according to claim 15, characterized in that in, The slot axis is disposed at an angle of approximately 65° or less relative to a centerline axis of the housing wall.

17. The device according to claim 11, characterized in that Wherein the housing wall comprises a flexible tip shroud, wherein the flexible tip shroud is integrally formed as part of the monolithic body.

18. The device according to claim 11, characterized in that Wherein the housing wall comprises a heat shield, wherein the heat shield is integrally formed as part of the one-piece body.

19. The device according to claim 11, characterized in that Wherein the housing wall comprises an annular hollow flange having an internal lattice structure, wherein the hollow flange is integrally formed as part of the monolithic body.

20. The device according to claim 11, characterized in that The stator blades have uneven spacing around the circumference of the housing.

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