JP2009243469A - Method and system of supporting stator constituent element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and a system of mounting a stator in a turbine engine with respect to a gas turbine engine constituent element. <P>SOLUTION: A method of supporting removable static elements in a turbine engine stator assembly includes steps of: engaging a stator hanger 210 located at a first location 221 on a first static element 231 with a post 96 located on a first static structure 91 whereby the post 96 supports at least a part of the weight of the first static element 231; making a stator stopper 220 located at a second location 222 on the first static element 231 that is located circumferentially apart from a first position 221 engaged with the stator hanger 210 located on a second static element 232; and making a hook 56 located at a third location 223 on the first static element 231 engaged with a second static structure 92 whereby the second static structure 92 supports at least a part of the weight of the first static element 231. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates generally to gas turbine engine components, and more particularly to mounting a stator in a turbine engine.

  Gas turbine engines typically have a core engine that mixes the air that flows into the core engine and the fuel is mixed with the compressed air and then burned to create a high energy gas stream. And a first or high pressure turbine that extracts energy from the gas stream to drive the compressor. In an aircraft turbofan engine, a second or low pressure turbine located downstream from the core engine extracts additional energy from the gas stream to drive the fan. This fan supplies the main driving force that the engine produces.

  Annular turbine nozzles are disposed between the combustor and the high pressure turbine and between the turbine stages. The turbine nozzle includes a pair of radially spaced inner and outer bands concentrically disposed about the longitudinal axis of the core engine and an airfoil supported between the inner and outer annular bands. Including. In the annular turbine nozzle assembly, these airfoils are spaced circumferentially relative to one another and extend radially relative to the core engine shaft. The annular turbine nozzle assembly is attached end to end with each other and has a plurality of arcuate segments (also referred to herein as one or more) forming a 360 degree circumferentially extending nozzle assembly. "Static blade"). Each turbine nozzle segment includes an arcuate segment of inner and outer bands and one or more airfoils attached between the inner and outer band segments.

  The turbine nozzle functions to direct and / or redirect the hot gas stream exiting the combustor in a more efficient direction to impinge on the rotor stage of the turbine and effect rotation of the rotor stage. The nozzle induction process also accelerates the gas flow, resulting in a decrease in static pressure between the inlet and outlet planes, and creating high pressure loads and moments on the nozzle and its support system. In addition, the turbine nozzle and its support system receive loads and moments on the radial support surface due to high thermal gradients due to hot combustion gases and cooling air.

  In conventional nozzle support systems, the nozzle segments are attached to the engine support structure by bolt joints or a combination of bolts and some form of fastening mechanism. However, the mechanical load and moment that the nozzle airfoil receives and the difference in thermal expansion and contraction cause a large bending stress in the nozzle and support part of such a mechanism. Furthermore, the holes required to receive the bolts inherently cause stress concentrations and can be a potential leak path. And the nuts and bolts required for assembly undesirably increase engine weight and increase engine assembly and disassembly time.

  For smaller turbine engine designs, the radially inner band extends adjacent to the rotating engine structure to which the turbine rotor stage is mounted, so the turbine nozzle is essentially radially cantilevered in a cantilevered manner. Some are supported only in bands. In some stages, such as the first stage nozzle, the nozzle is attached to the engine stationary structure by a radially inner mount or flange structure coupled to the inner band. The radially outer band is not mechanically held but is supported against axial forces by a circumferential engine flange. In other stages, such as the engine's second stage turbine, the turbine nozzles are mounted with a radially outer band, but may be free with a radially inner band. In either design, the use of bolts and clamps in circumferential positions around the turbine nozzle band constrains the band that is hotter than the structure to which it is attached, so the radial band of the outer band of the nozzle Warpage occurs, resulting in out-of-roundness and stress of the airfoil attached to the band. Such stress in the airfoil can lead to the formation of cracks in the airfoil.

U.S. Pat. No. 3,765,791 US Pat. No. 4,883,405 US Pat. No. 5,176,496 US Pat. No. 5,224,822 US Pat. No. 5,249,920 US Pat. No. 5,271,714 US Pat. No. 5,343,694 US Pat. No. 5,372,476 US Patent No. 7,112,042

  There is a need to improve the attachment and support of stator components such as turbine nozzle segments to engine support structures and to develop other designs and methods. Accordingly, in a method and system for attaching stationary elements, such as turbine engine vanes, to an engine support structure, it is desirable to have an attachment method and system that repels loads and moments without the use of bolts and nuts. It would be desirable to have a repulsive mounting system for a turbine stator component such that the stator can be easily replaced in the assembly.

  The above-described needs can be met by the illustrative embodiments described herein that provide a method and system for supporting a removable stationary element in a turbine engine. The method includes engaging a stator hanger disposed in a first position on the first stationary element with a post disposed on the first stationary structure so that the post has at least a weight of the first stationary element. Supporting a portion; engaging a stator stopper disposed at a second position on the first stationary element circumferentially spaced from the first position with a stator hanger disposed on the second stationary element; The second stationary structure supporting at least a portion of the weight of the second stationary element by engaging a hook located at a third position on the first stationary element with the second stationary structure. The stator blades are supported by a repulsive mounting system comprising a stator hanger disposed on the outer band at the first position and a stator stopper disposed at a second position spaced circumferentially from the first position.

The subject matter of the present invention is particularly pointed out in the appended claims. The invention may be better understood by reference to the following description in conjunction with the accompanying drawings.
1 is a longitudinal cross-sectional view of a portion of a gas turbine showing a rotor and a stator including exemplary embodiments of the present invention. 2 is a longitudinal cross-sectional view of a stator component in the gas turbine shown in FIG. 1, including an exemplary embodiment of the present invention. 1 is an isometric view of a stator assembly having an exemplary embodiment of a stator mounting system according to the present invention. FIG. 1 is an isometric view of a vane having a repulsive mounting system according to an illustrative embodiment of the invention. FIG. FIG. 6 is an isometric view of a stator assembly having yet another embodiment of a stator mount system according to the present invention. FIG. 5 is an isometric view of a vane having a repulsive mounting system according to yet another embodiment of the present invention. FIG. 4 is an isometric view of the shroud hanger shown in FIG. 3.

  Referring to the drawings in which like reference numerals refer to like components throughout the drawings, FIG. 1 shows a longitudinal section of a portion of an exemplary gas turbine 10 showing a rotor and stator including exemplary embodiments of the present invention. The figure is shown. The illustrative gas turbine 10 shown in FIG. 1 comprises a first stage turbine rotor 21, a second stage turbine rotor 22, and a second stage turbine nozzle 23 disposed between both in the axial direction. The turbine blades 20 and 24 are arranged circumferentially around the turbine centerline 11 at the edges of the first and second stage rotors, respectively. The illustrative example shown herein shows a support system 300 that supports stationary elements, such as turbine nozzles 23, using adjacent stationary structures 91, 92, such as shroud hangers 32, 90, in a turbine.

  FIG. 2 shows an enlarged view of the second stage turbine nozzle shown in FIG. The second stage turbine nozzle 23 includes an inner band 51, an outer band 52, and an airfoil portion 50 extending between the inner band 51 and the outer band 52. The turbine nozzle shown herein has one airfoil between the inner and outer bands. However, in other embodiments of the present invention, multiple airfoils may be provided in the turbine nozzle segment between the inner and outer bands. The inner band 51 and the outer band 52 form a flow path for combustion gas. The turbine nozzle airfoil 50 may be hollow (for example, as shown in FIG. 5), and the cooling air supplied from the pulley 100 may be circulated through the hollow airfoil 50. The nozzle segment 23 including the outer band may be fabricated from a one-piece casting having a vane airfoil, an outer band, and an inner band. As an alternative, the nozzle segments may be made by any suitable conventional joining method, such as brazing of individual subcomponents such as vane airfoils, outer bands and inner bands.

  The outer band 52 and the inner band 51 of each nozzle segment 23 have an arcuate shape so as to form an annular flow path when multiple nozzle segments are assembled about the turbine centerline 11. Yes. The turbine nozzle segment 23 forms an annular turbine nozzle assembly having inner and outer bands 51, 52 that form an annular flow path through which hot gas passes when assembled in the engine. In the turbine 10 shown in FIG. 1, the second stage turbine nozzle receives a flow coming out of the first stage turbine and redefines the direction into the second stage turbine.

  With reference to FIGS. 2 and 3, the illustrative embodiment of the second stage nozzle shown in these figures is held in place by the stator support system 300. An exemplary outer band cantilever mounting system is shown in FIGS. In the illustrated exemplary embodiment, the axial front end 61 of the outer band 52 has a front hook 56 that extends circumferentially along the circumferential length of the nozzle segment 23. The front hook 56 rests on the arcuate rail 40 that protrudes in the axial direction from the rear end of the first stage shroud hanger 32.

  FIG. 3 shows an isometric view of a stator assembly 200 having an exemplary embodiment of a stator component mounting system 300 according to the present invention. For convenience of illustration, FIG. 3 shows only two outer bands 52 positioned in the circumferential direction. Each outer band 52 has a repulsive mounting system 205 including a stator hanger 210 disposed at a first position 221 such as near the rear end position shown in FIG. 3 and a stator stopper 220 at a second position 222. In the drawing, the stator stopper 220 is arranged in the circumferential direction away from the stator hanger 210 in the vicinity of the rear end portion on the outer band 52. The support system 300 further includes a hook 56 disposed in the third position 223 shown in FIGS. 2 and 3 near the axial front end 61. As shown in FIG. 3, the front hook may have an arcuate shape that engages an arcuate rail 40 on a stationary structure 92 disposed near the front hook 56. Herein, as shown in these figures, the arcuate rail 40 forms a portion of the shroud hanger 32 that is disposed axially forward from the outer band 52.

  FIG. 4 shows an isometric view of a vane 53 having a repulsive mounting system 205 in accordance with an illustrative embodiment of the present invention. The stator hanger 210 and the stator stopper 220 are disposed near the rear end portion 60, and the front hook 56 is disposed near the front end portion 61 of the outer band 52. Stator hanger 210 comprises a stem portion 64 having a mass of material (referred to herein as “hammer”, identified as member 68) having a hammer-like shape disposed at its radially outer end. This stator hanger has a hanger claw 71 disposed in the vicinity of the radially outer end portion of the stem portion 64. The stator stopper 220 is disposed away from the stator hanger 210 in the circumferential direction. Stator stopper 220 includes a paddle portion 80 having a paddle rear surface 83 and an end surface 86.

  At the time of assembly, the hanger claw 71 engages with a post 96 disposed on the first support structure 91 such as the shroud hanger 90. As shown in FIG. 3, the stator stopper 220 disposed on the outer band 52 engages with a stator hanger 210 disposed on the outer band 52 adjacent in the circumferential direction. Specifically, the paddle rear surface 83 is disposed adjacent to the stem portion 64 of the stator hanger 210. A portion of the upper portion of the stator stopper 220 engages with a radially inner portion of the hammer 68. When the turbine is not operating, the hanger claw 71 is placed on the post 96 and supports the nozzle in a low temperature state. 3 and 4, the rotation prevention tab 72 is arranged near the end of the hanger claw 71. The anti-rotation tab 72 engages with the post 96 to prevent the nozzle segment 23 from rotating during assembly.

  During turbine operation, the stem portion 64 of the hammer 68 repels against the post 96 against a load in the tangential direction of the nozzle. The upper portion of the stator stopper 220 disposed at the second position 222 on the inclined surface opposite to the outer band 52 is a hammer of the outer band 52 adjacent in the circumferential direction of the adjacent nozzle segment 23 with respect to a radial moment. Rebound to fit within 68. The upper portion of the hammer 70 is repelled so as to contact the shroud support portion of 360 degrees in the radial direction. In addition to the hammer 70, the nozzle front hook 56 also repels to fit within the support structure 92 against radial loads. The axial moment is repelled by the paddle 80 to engage the hammer stem portion 64 of the adjacent nozzle segment and the adjacent support structure 91. The axial load is repelled to abut against an adjacent stationary structure such as a second stage shroud hanger. When nozzle segment 23 is assembled into a complete nozzle assembly, all the axial loads and moments and circumferences are simultaneously adjusted so that all nozzle segments abut 360 degree shroud supports for radial moments. Repulsive to abut the adjacent support structure against the directional load. Such features of the support system 300 provide an improvement over the prior art that increases the roundness of the nozzle assembly about the turbine shaft 11 and consequently reduces the relative clearance between the nozzle segments.

  FIG. 5 illustrates a stator assembly 200 having yet another embodiment of a stator mounting system 300 according to the present invention. Three nozzle segments are shown, each segment having a single vane. The illustrated nozzle blade 100 has a hollow cavity through which the cooling air flow passes. Another embodiment of the stator hanger 210 is shown in FIGS. The hanger pawl engages a post 96 disposed on an adjacent support structure 91 such as a shroud hanger. In this alternative embodiment, the rebound mount system 205 includes an anti-rotation tab 172 disposed on the repellent mount 63 (see FIG. 6). The engagement between the stator hanger 210 and the stator stopper 220 and the support structure 91 is as described above.

  FIG. 7 illustrates a shroud hanger 90 that may be used with the stationary element mounting system 300 described herein. The shroud hanger 90 has an inner rail 94 that has an arcuate shape. The inner rail can support a conventional turbine shroud. The shroud hanger 90 has an outer rail that is also arcuate in shape. The outer rail engages with the casing 34 and repels the load so that the casing 34 abuts against the load. The shroud hanger has at least one post 96 that extends generally in the axial direction, as shown in FIGS. As described above, the post supports the stationary blade 23 and transmits a load to the shroud hanger and the casing via the post 96. The shroud hangers, nozzles and other components shown herein are made from conventional turbine materials such as Rene 80 and Inconel 718, which have high heat resistance.

  The present invention has been disclosed herein using examples including the best mode. This allows those skilled in the art to implement and utilize the present invention. The patentable scope of the invention is defined in the appended claims, and includes other examples that occur to those skilled in the art. Such other embodiments include components that do not differ from the language recited in the claims, or include components that are substantially equivalent to the language recited in the claims. It is intended to be within the scope of the claims.

Claims (14)

An airfoil (50);
An outer band (52) disposed on a radially outer portion of the airfoil (50),
The outer band (52) comprises a stationary blade (53) including a repulsive mounting system (205) that supports the stationary blade (53).   The repulsive mounting system (205) includes a stator hanger (210) disposed on the outer band (52) at a first position (221) and a second position spaced circumferentially from the first position (221). The stator blade (53) according to claim 1, comprising a stator stopper (220) disposed on (222).   The stator blade (53) according to claim 2, wherein the stator hanger (210) includes a stem portion (64), a hammer (68), and a hanger claw (71).   The stationary blade (53) according to claim 3, wherein the hanger claw (71) includes an anti-rotation tab (72) disposed at an end of the hanger claw (71).   The stator blade (53) according to claim 2, wherein the stator stopper (220) includes a paddle (80).   The vane (53) of claim 2, further comprising an anti-rotation post (172) disposed on the rebound tool mount (63). A method for supporting a removable stationary element in a turbine engine stator assembly comprising:
By engaging a stator hanger (210) disposed in a first position (221) on a first stationary element (231) with a post (96) disposed on a first stationary structure (91), the post (96) supporting a portion of the weight of the first stationary element (231);
A stator stopper (220) disposed at a second position (222) circumferentially spaced from the first position (221) on the first stationary element (231) is disposed on the second stationary element (232). Engaging said stator hanger (210);
A second stationary structure (92) is engaged with a second stationary structure (92) by engaging a hook (56) disposed in a third position (223) on the first stationary element (231). Supporting at least a portion of the weight of one stationary element (231).   The method further includes reducing rotation of the first stationary element (231) during assembly by engaging an anti-rotation tab (72) disposed on the stator hanger (210) with the post (96). The method according to claim 7.   Reducing rotation of the first stationary element (231) during assembly by engaging an anti-rotation post (172) disposed on the first stationary element (231) with the post (96); The method of claim 7, further comprising:   The step of engaging the stator stopper (220) is performed by sliding a portion of the stator stopper (220) under a portion of a hammer top (70) that forms a portion of the stator hanger (210). 10. The method according to any one of claims 7 to 9, wherein: A system (300) for supporting a removable stationary element in a turbine engine comprising:
A stator hanger (210) disposed in a first position (221) on the first stationary element (231);
A post (96) disposed on the first stationary structure (91) for supporting at least a portion of the weight of the first stationary element (231);
A stator stopper (220) disposed at a second position (222) circumferentially spaced from the first position (221) on the first stationary element (231);
A hook (56) disposed in a third position (223) on the first stationary element (231);
A system (300) comprising a second stationary structure (92) that engages the hook (56) so that the second stationary structure (92) supports at least a portion of the weight of the first stationary element (231). ).   A portion of the stator stopper (220) slides under a portion of a hammer top (70) that forms a portion of a stator hanger (210) disposed on a circumferentially adjacent second stationary element (232). The system of claim 11, configured to be able to.   The system according to claim 11 or 12, wherein the first stationary element (231) is a turbine nozzle (115).   The system of any one of claims 11 to 13, wherein the first stationary structure (91) is a turbine shroud hanger (116).

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