Stator blade segment and axial flow compressor with the same

Abstract

To effectively damp vibrations of a stator blade in at least the radial direction.SOLUTION: A stator blade segment comprises a stator blade, a holder, and an elastic body. The stator blade has a blade body having an airfoil-shaped cross section perpendicular to the radial direction relative to the axis, and an inner shroud provided at an end of the blade body in the radial direction. The inner shroud has an elastic force receiving surface that faces an axis upstream side between the axis upstream side and an axis downstream side in the axis direction in which the axis extends, and a friction surface that faces the axis upstream side and extends in the radial direction. The holder has a support surface that is located on the axis upstream side of the elastic force receiving surface and faces the elastic force receiving surface at an interval therefrom in the axial direction. The elastic body is disposed so that elastic force is generated in the axial direction between the elastic force receiving surface of the inner shroud and the support surface of the holder.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a stator vane segment and an axial flow compressor including the same. [Background technology]

[0002] An axial flow compressor has a rotor that rotates about an axis, a casing that covers the rotor, and a plurality of stator blade rows. The rotor has a rotor shaft that extends axially about the axis, and a plurality of rotor blade rows attached to the rotor shaft. The plurality of rotor blade rows are aligned in the axial direction. Each rotor blade row has a plurality of rotor blades aligned in the circumferential direction about the axis. One of the plurality of stator blade rows is arranged axially downstream of each of the plurality of rotor blade rows. Each stator blade row is provided inside the casing. Each stator blade row includes a stator blade segment having a plurality of stator blades aligned in the circumferential direction.

[0003] The following Patent Document 1 discloses a stator vane segment for this axial flow compressor.

[0004] This stator vane segment has a plurality of stator vanes arranged in a circumferential direction about the axis, a holder, and a spring. Each of the plurality of stator vanes has a blade body, an outer shroud, and an inner shroud. The blade body has an airfoil-shaped cross section perpendicular to the radial direction about the axis and extends in the radial direction. The outer shroud is provided at the radially outer end of the blade body. The outer shroud of each of the plurality of stator vanes is fixed to the casing. The inner shroud is provided at the radially inner end of the blade body. The holder covers a portion of the inner shroud of each of the plurality of stator vanes. The spring is disposed within this holder.

[0005] The inner shroud has an elastic force receiving surface facing the axial downstream side. The holder has a support surface located downstream of the elastic force receiving surface in the axial direction and facing the elastic force receiving surface in the axial direction. The spring is arranged so that an elastic force is generated in the axial direction between the elastic force receiving surface of the inner shroud and the support surface of the holder. The spring, which is in contact with the support surface of the holder, pushes the inner shroud upstream in the axial direction. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 06-346703 Summary of the Invention [Problem to be solved by the invention]

[0007] During operation of an axial flow compressor, the stator blades vibrate in various directions, and therefore, in order to damp this vibration, techniques such as those disclosed in Patent Document 1 have been developed.

[0008] An object of the present disclosure is to provide a stator vane segment that can effectively damp vibrations of the stator vane in at least the radial direction, and an axial flow compressor including the same. [Means for solving the problem]

[0009] In one aspect of the present invention, a stator vane segment comprises: The turbine comprises a stator vane, a holder for holding a portion of the stator vane, and an elastic body disposed within the holder. The stator vane has a blade body having an airfoil-shaped cross section perpendicular to the radial direction relative to the axis, and an inner shroud provided at the radial end of the blade body. The blade body has an axially upstream side and an axially downstream side in the axial direction in which the axis extends, and a leading edge that is located at the axially most upstream side of the blade body and a trailing edge that is located at the axially most downstream side of the blade body. The inner shroud has an elastic force receiving surface facing the axial upstream side and a friction surface that faces the axially upstream side and extends in the radial direction. The holder is configured to cover a portion of the inner shroud. The holder has a support surface located upstream of the elastic force receiving surface and facing the elastic force receiving surface at a distance in the axial direction. The elastic body is disposed so as to generate an elastic force in the axial direction between the elastic force receiving surface of the inner shroud and the support surface of the holder, and the friction surface of the inner shroud is in contact with a part of the holder or a part of the elastic body.

[0010] In this aspect, the elastic body in the holder pushes the inner shroud axially downstream, so that a part of the holder or a part of the elastic body comes into contact with the friction surface of the inner shroud.

[0011] Suppose that the inner shroud vibrates in the radial direction during operation of the axial flow compressor. In this case, in this aspect, the friction surface of the inner shroud slides in the radial direction against a part of the holder or a part of the elastic body. In this aspect, the friction surface of the inner shroud slides against a part of the holder or a part of the elastic body, thereby damping the radial vibration of the inner shroud.

[0012] During operation of an axial compressor, gas that flows into the casing of the axial compressor is sent downstream along the axis. The pressure of this gas gradually increases as it is sent downstream along the axis. Therefore, during operation of the axial compressor, a force acts on the stator vane segment from the axial downstream side of the stator vane segment toward the axial upstream side. In the stator vane segment, the stator vane is fixed to the compressor casing, but the holder is not fixed to the compressor casing. Therefore, the force from the gas acts to push the holder upstream along the axis relative to the stator vane.

[0013] Suppose a spring is disposed inside the holder so that the spring can push the inner shroud axially upstream, as in the technology described in Patent Document 1 described in the Background Art section. In this case, the elastic force of the spring is canceled out by the force from the gas that pushes the holder axially upstream relative to the stator vane. As a result, the force in the direction of contact between the friction surface of the inner shroud and the contact surface of the holder weakens, or this force disappears depending on the operating state of the axial flow compressor. Therefore, in this case, the vibration damping effect achieved by providing the spring is reduced.

[0014] On the other hand, in this aspect, an elastic body is disposed inside the holder so that the elastic body can push the inner shroud toward the axial downstream side. In this case, the force P from the gas that pushes the holder toward the axial upstream side relative to the stator vane and the elastic force of the spring both act in directions that bring the friction surface of the inner shroud and the contact surface of the holder into contact. Therefore, in this aspect, it is possible to effectively damp radial vibration of the inner shroud.

[0015] An axial flow compressor according to one aspect of the present invention for achieving the above object comprises: The axial flow compressor includes a stator vane segment of the one aspect, a compressor rotor rotatable about the axis, and a compressor casing that covers the stator vane segment and the compressor rotor and to which the stator vane segment is attached. [Effects of the Invention]

[0016] According to one aspect of the present disclosure, vibrations of the stator vanes in at least the radial direction can be effectively damped. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a schematic cross-sectional view of a gas turbine in one embodiment according to the present disclosure. [Figure 2] FIG. 2 is a perspective view of a vane segment in the first embodiment according to the present disclosure. [Figure 3] FIG. 3 is a view taken along the arrow III in FIG. 2. [Figure 4] FIG. 4 is an enlarged view of part IV in FIG. [Figure 5] FIG. 10 is a side view of a main portion of a vane segment in a second embodiment according to the present disclosure. [Figure 6] FIG. 10 is a perspective view of a second elastic body in a second embodiment according to the present disclosure. [Figure 7] FIG. 11 is a side view of a main portion of a vane segment in a third embodiment according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, embodiments and modifications of a stator vane segment according to the present disclosure, and further, embodiments of an axial flow compressor including the stator vane segment will be described with reference to the drawings.

[0019] "Embodiment of Axial Flow Compressor" As shown in FIG. 1, the gas turbine 10 includes a compressor 20 that compresses air A, a plurality of combustors 30 that burn fuel F in the air A compressed by the compressor 20 to generate combustion gas G, and a turbine 40 that is driven by the combustion gas G.

[0020] The compressor 20 has a compressor rotor 21 that rotates about an axis Ar, a compressor casing 25 that covers the compressor rotor 21, and a plurality of stator blade rows 24. The turbine 40 has a turbine rotor 41 that rotates about the axis Ar, a turbine casing 45 that covers the turbine rotor 41, and a plurality of stator blade rows 44. Note that, hereinafter, the direction in which the axis Ar extends is referred to as the axial direction Da, the circumferential direction about the axis Ar is simply referred to as the circumferential direction Dc, and the direction perpendicular to the axis Ar is referred to as the radial direction Dr. Furthermore, one side of the axial direction Da is referred to as the axial upstream side Dau, and the opposite side is referred to as the axial downstream side Dad. Furthermore, the side of the radial direction Dr that approaches the axis Ar is referred to as the radially inner side Dri, and the opposite side is referred to as the radially outer side Dro.

[0021] The compressor 20 is disposed on the axial upstream side Dau with respect to the turbine 40 .

[0022] The compressor rotor 21 and the turbine rotor 41 are located on the same axis Ar and are connected to each other to form the gas turbine rotor 11. To this gas turbine rotor 11, for example, a rotor of a generator GEN is connected. The gas turbine 10 further includes an intermediate casing 16. This intermediate casing 16 is arranged between the compressor casing 25 and the turbine casing 45 in the axial direction Da. The compressor casing 25, the intermediate casing 16, and the turbine casing 45 are connected to each other to form the gas turbine casing 15.

[0023] The compressor rotor 21 has a rotor shaft 22 extending in the axial direction Da around the axis Ar, and a plurality of rotor blade rows 23 attached to the rotor shaft 22. The plurality of rotor blade rows 23 are aligned in the axial direction Da. Each rotor blade row 23 has a plurality of rotor blades aligned in the circumferential direction Dc. One of the plurality of stator blade rows 24 is arranged on the axial downstream side Dad of each of the plurality of rotor blade rows 23. Each stator blade row 24 is provided inside a compressor casing 25. Each stator blade row 24 has a plurality of stator blades aligned in the circumferential direction Dc. Therefore, the compressor 20 is a multi-stage axial compressor. That is, the axial compressor in this embodiment is the compressor 20.

[0024] The turbine rotor 41 has a rotor shaft 42 extending in the axial direction Da centered on the axis Ar, and a plurality of rotor blade rows 43 attached to the rotor shaft 42. The plurality of rotor blade rows 43 are aligned in the axial direction Da. Each rotor blade row 43 has a plurality of rotor blades aligned in the circumferential direction Dc. One of the plurality of stator blade rows 44 is arranged on the axial upstream side Dau of each of the plurality of rotor blade rows 43. Each stator blade row 44 is provided inside the turbine casing 45. Each stator blade row 44 has a plurality of stator blades aligned in the circumferential direction Dc.

[0025] The plurality of combustors 30 are attached to the intermediate casing 16 and are arranged in a line in the circumferential direction Dc around the axis Ar.

[0026] Each of the plurality of stator vane rows 24 in the compressor includes a stator vane segment having a plurality of stator vanes arranged in the circumferential direction Dc. Various embodiments and modifications of the stator vane segment will be described below.

[0027] "First embodiment of stationary vane segment" Hereinafter, a first embodiment of the stator vane segment will be described with reference to FIGS.

[0028] As shown in FIGS. 2 and 3, the stator vane segment VS in this embodiment includes a plurality of stator vanes 50, a connecting plate 89, a holder 70, and an elastic body 80a provided for each of the plurality of stator vanes 50.

[0029] Each of the multiple stator blades 50 has a blade body 51 whose cross section perpendicular to the radial direction Dr is shaped like an airfoil and extends in the radial direction Dr, an outer shroud 55 provided at the end of the radially outer side Dro of the blade body 51, and an inner shroud 60 provided at the end of the radially inner side Dri of the blade body 51.

[0030] The blade body 51 has a leading edge 51f, Dau, which is the most axially upstream side of the blade body 51, and a trailing edge 51b, Dad, which is the most axially downstream side of the blade body 51. The area between the outer shroud 55 and the inner shroud 60 in the radial direction Dr is part of a gas flow path 59 through which gas A to be compressed flows toward the axially downstream side Dad. Therefore, the blade body 51 is disposed in this gas flow path 59.

[0031] The connecting plate 89 connects the outer shrouds 55 of the plurality of stator blades 50 arranged in the circumferential direction Dc to each other.

[0032] The holder 70 covers a portion of the inner shroud 60 for each of the plurality of stator blades 50 arranged in the circumferential direction Dc, and holds the inner shroud 60 for each of the plurality of stator blades 50.

[0033] The elastic body 80a is disposed inside the holder 70 so that the inner shroud 60 of each of the plurality of stator blades 50 can be pressed toward the axial downstream side Dad relative to the holder 70.

[0034] As shown in FIGS. 3 and 4, the inner shroud 60 has a shroud main body plate 61, an upstream leg portion 62u, an upstream lip portion 64u, a downstream leg portion 62d, and a downstream lip portion 64d.

[0035] The shroud body plate 61 is provided at the end of the radially inner side Dri of the blade body 51. The shroud body plate 61 is a plate-shaped member extending in the axial direction Da and the circumferential direction Dc. The shroud body plate 61 has a gas path surface 61p facing the radially outer side Dro, a counter-gas path surface 61pa facing the radially inner side Dri and back-to-back with the gas path surface 61p, a front surface 61f facing the axial upstream side Dau, and a rear surface 61b facing the axial downstream side Dad and back-to-back with the front surface 61f. The gas path surface 61p defines a part of the inner peripheral edge of the gas flow path 59 described above.

[0036] The upstream leg 62u extends radially inward Dri from a position on the anti-gas path surface 61pa of the shroud body plate 61 that is axially upstream Dau of the center of the shroud body plate 61 in the axial direction Da and axially downstream Dad of the front surface 61f of the shroud body plate 61. The upstream lip 64u extends radially inward Dri from an end of the radially inner Dri of the upstream leg 62u to the axial upstream side Dau. A shroud upstream groove 69u that is recessed toward the axial downstream side Dad is formed between the shroud body plate 61 and the upstream lip 64u, axially upstream Dau of the upstream leg 62u.

[0037] The downstream leg 62d extends radially inward Dri from a position on the anti-gas path surface 61pa of the shroud body plate 61 that is axially downstream Dad of the center of the shroud body plate 61 in the axial direction Da and axially upstream Dau of the rear surface 61b of the shroud body plate 61. The downstream lip 64d extends from an end of the radially inner Dri of the downstream leg 62d to the axial downstream side Dad. A shroud downstream groove 69d recessed toward the axial upstream side Dau is formed between the shroud body plate 61 and the downstream lip 64d, at a position axially downstream Dad of the downstream leg 62d.

[0038] The holder 70 has a holder bottom plate 71, an upstream leg portion 72u, an upstream flange portion 74u, a downstream leg portion 72d, and a downstream flange portion 74d.

[0039] The holder bottom plate 71 is a plate-shaped member extending in the axial direction Da and the circumferential direction Dc. The holder bottom plate 71 has a bottom surface 71b facing the radially outer side Dro and a seal installation surface 71s facing the radially inner side Dri and back-to-back with the bottom surface 71b. A seal 78 is provided on the seal installation surface 71s to seal between the outer peripheral surface of the rotor shaft 22 shown in FIG. 1 and the holder 70.

[0040] The upstream leg 72u extends from the end of the holder bottom plate 71 on the axial upstream side Dau to the radially outer side Dro. The upstream flange 74u extends from the end of the upstream leg 72u on the radially outer side Dro to the axial downstream side Dad. A holder upstream groove 79u recessed toward the axial upstream side Dau is formed between the holder bottom plate 71 and the upstream flange 74u, downstream of the upstream leg 72u on the axial downstream side Dad. The upstream flange 74u fits into the shroud upstream groove 69u described above. Furthermore, the upstream lip 64u of the inner shroud 60 fits into the holder upstream groove 79u.

[0041] The downstream leg 72d extends radially outward from the end of the holder bottom plate 71 on the axial downstream side Dad. The downstream flange 74d extends radially outward from the end of the downstream leg 72d on the radially outward side Dro to the axial upstream side Dau. A holder downstream groove 79d recessed toward the axial downstream side Dad is formed between the holder bottom plate 71 and the downstream flange 74d, on the axial upstream side Dau of the downstream leg 72d. The downstream flange 74d is recessed into the shroud downstream groove 69d described above. Furthermore, the downstream lip 64d of the inner shroud 60 is recessed into the holder downstream groove 79d.

[0042] The downstream flange portion 74d of the holder 70 faces the axial upstream side Dau and has a contact surface 76a extending in the radial direction Dr and the circumferential direction Dc. The downstream leg portion 62d of the inner shroud 60 faces the axial downstream side Dad and has a friction surface 66a extending in the radial direction Dr and the circumferential direction Dc. The contact surface 76a of the holder 70 faces the friction surface 66a of the inner shroud 60 in the axial direction Da.

[0043] The upstream leg portion 72u of the holder 70 has a support surface 77a that faces the axial downstream side Dad and extends in the radial direction Dr and the circumferential direction Dc. Furthermore, the upstream lip portion 64u of the inner shroud 60 has an elastic force receiving surface 67a that faces the axial upstream side Dau and extends in the radial direction Dr and the circumferential direction Dc. The support surface 77a of the holder 70 is located on the axial upstream side Dau of the elastic force receiving surfaces 67a of the inner shroud 60 for each of the plurality of stator vanes 50, and faces the elastic force receiving surfaces 67a of each of the plurality of stator vanes 50 at an interval in the axial direction Da.

[0044] A plurality of elastic bodies 80a are arranged in the holder upstream groove 79u between the support surface 77a of the holder 70 and the elastic force receiving surfaces 67a of the plurality of stator blades 50 so as to generate an elastic force in the axial direction Da. In this embodiment, the elastic bodies 80a are formed by stacking a plurality of disc springs 81 in the axial direction Da.

[0045] A spacer 82 is disposed in the holder upstream groove 79u between the support surface 77a of the holder 70 and the elastic bodies 80a of each of the plurality of stator blades 50. Note that the spacer 82 may also be disposed in the holder upstream groove 79u between the elastic bodies 80a of each of the plurality of stator blades 50 and the elastic force receiving surfaces 67a of each of the plurality of stator blades 50. In some cases, the spacer 82 may be omitted.

[0046] In this embodiment, the elastic bodies 80a for each of the plurality of stator vanes 50 in the holder 70 press the inner shrouds 60 for each of the plurality of stator vanes 50 toward the axial downstream side Dad. As a result, the contact surfaces 76a of the holder 70 come into contact with the friction surfaces 66a of the inner shrouds 60 for each of the plurality of stator vanes 50.

[0047] Suppose that the inner shroud 60 vibrates in the radial direction Dr during operation of the axial flow compressor. In this case, in this embodiment, the friction surfaces 66a of the inner shroud 60 for each of the plurality of stator vanes 50 slide in the radial direction Dr against the contact surfaces 76a of the holder 70. Furthermore, the elastic force receiving surfaces 67a of the inner shroud 60 for each of the plurality of stator vanes 50 slide in the radial direction Dr against the elastic bodies 80a for each of the plurality of stator vanes 50 as friction surfaces. In this embodiment, the friction surfaces 66a of the inner shroud 60 slide against the contact surfaces 76a of the holder 70, and further, the elastic force receiving surfaces 67a of the inner shroud 60 slide against the elastic bodies 80a, thereby damping the radial vibration of the inner shroud 60.

[0048] Furthermore, suppose that the inner shroud 60 vibrates in the circumferential direction Dc during operation of the axial flow compressor. In this case, in this embodiment, the friction surfaces 66a of the inner shroud 60 for each of the plurality of stator vanes 50 slide in the circumferential direction Dc against the contact surfaces 76a of the holder 70. Furthermore, the elastic force receiving surfaces 67a of the inner shroud 60 for each of the plurality of stator vanes 50 slide in the circumferential direction Dc against the elastic bodies 80a for each of the plurality of stator vanes 50 as friction surfaces. In this embodiment, the friction surfaces 66a of the inner shroud 60 slide against the contact surfaces 76a of the holder 70, and further, the elastic force receiving surfaces 67a of the inner shroud 60 slide against the elastic bodies 80a, thereby damping the circumferential vibration of the inner shroud 60.

[0049] During operation of the axial compressor, gas that has flowed into the casing of the axial compressor is sent to the axial downstream side Dad. The pressure of this gas gradually increases as it is sent to the axial downstream side Dad. For this reason, during operation of the axial compressor, a force P acts on the stator vane segment VS from the axial downstream side Dad of the stator vane segment VS toward the axial upstream side Dau. In the stator vane segment VS, the stator vane 50 is fixed to the compressor casing 25 (see FIG. 1 ), but the holder 70 is not fixed to the compressor casing 25. For this reason, the force P from the gas acts as a force that pushes the holder 70 toward the axial upstream side Dau relative to the stator vane 50.

[0050] Suppose that a spring is disposed inside the holder so that the spring can press the inner shroud toward the axial upstream side Dau, as in the technology described in Patent Document 1 described in the Background Art section. In this case, the elastic force of the spring is canceled out by a force P from the gas that presses the holder toward the axial upstream side Dau relative to the stator vane. As a result, the force in the direction of contact between the friction surface of the inner shroud and the contact surface of the holder weakens, or this force disappears depending on the operating state of the axial flow compressor. For this reason, in this case, the vibration damping effect achieved by providing the spring is reduced.

[0051] On the other hand, in the present embodiment, the elastic body 80a is disposed inside the holder 70 so that the elastic body 80a can press the inner shroud 60 toward the axial downstream side Dad. In this case, the force P from the gas and the elastic force of the spring, which press the holder 70 toward the axial upstream side Dau relative to the stator vane 50, both act in directions that bring the friction surface 66a of the inner shroud 60 into contact with the contact surface 76a of the holder 70. For this reason, in the present embodiment, vibrations of the inner shroud 60 in the radial direction Dr and the circumferential direction Dc can be effectively damped.

[0052] "Second embodiment of stationary vane segment" Hereinafter, a second embodiment of the stator vane segment will be described with reference to FIGS.

[0053] Like the stator vane segment VS in the first embodiment described with reference to Fig. 2, the stator vane segment VS in this embodiment also includes a plurality of stator vanes 50, a connecting plate 89, a holder 70, and an elastic body 80a provided for each of the plurality of stator vanes 50. As shown in Fig. 5, the stator vane segment VS in this embodiment further includes a second elastic body 80b in addition to the first elastic body 80a, which is the elastic body 80a in the first embodiment.

[0054] The inner shroud 60 has a second elastic force receiving surface 67b in addition to the first elastic force receiving surface 67a, which is the elastic force receiving surface 67a in the first embodiment. This second elastic force receiving surface 67b is located on the anti-gas path surface 61pa of the shroud body plate 61 and is a portion between the upstream leg portion 62u and the downstream leg portion 62d of the inner shroud 60. The holder 70 has a second support surface 77b in addition to the first support surface 77a, which is the support surface 77a in the first embodiment. This second support surface 77b is located on the bottom surface 71b of the holder 70 and is a portion between the upstream leg portion 62u and the downstream leg 62d of the inner shroud 60. This second support surface 77b faces the second elastic force receiving surface 67b at an interval in the radial direction Dr.

[0055] The inner shroud 60 has a second friction surface 66b in addition to the first friction surface 66a, which is the friction surface 66a in the first embodiment. The second friction surface 66b is a surface that faces the radially outer side Dro of the upstream lip portion 64u of the inner shroud 60 and extends in the axial direction Da and the circumferential direction Dc, and a surface that faces the radially outer side Dro of the downstream lip portion 64d of the inner shroud 60 and extends in the axial direction Da and the circumferential direction Dc. The holder 70 has a second contact surface 76b in addition to the first contact surface 76a, which is the contact surface 76a in the first embodiment. The second contact surface 76b is a surface that faces the radially inner side Dri of the upstream flange portion 74u of the holder 70 and extends in the axial direction Da and the circumferential direction Dc, and a surface that faces the radially inner side Dri of the downstream flange portion 74d of the holder 70 and extends in the axial direction Da and the circumferential direction Dc. The second friction surface 66b of the upstream lip portion 64u of the inner shroud 60 faces the second contact surface 76b of the upstream flange portion 74u of the holder 70 in the radial direction Dr. The second friction surface 66b of the downstream lip portion 64d of the inner shroud 60 faces the second contact surface 76b of the downstream flange portion 74d of the holder 70 in the radial direction Dr.

[0056] The second elastic body 80b is disposed between the second elastic force receiving surface 67b of the shroud main body plate 61 and the second support surface 77b of the holder 70 so that an elastic force acts in the radial direction Dr. As shown in Fig. 6, the second elastic body 80b is a leaf spring that extends in the circumferential direction Dc and undulates in the radial direction Dr.

[0057] In the present embodiment, similarly to the first embodiment, the first elastic bodies 80a for each of the plurality of stator vanes 50 in the holder 70 push the inner shrouds 60 for each of the plurality of stator vanes 50 toward the axial downstream side Dad. As a result, the first contact surfaces 76a of the holder 70 come into contact with the first friction surfaces 66a of the inner shrouds 60 for each of the plurality of stator vanes 50. Therefore, similarly to the first embodiment, in the present embodiment, vibrations of the inner shroud 60 in the radial direction Dr and the circumferential direction Dc can be effectively damped.

[0058] In the present embodiment, the second elastic bodies 80b in the holder 70 further press the inner shrouds 60 of each of the plurality of stator vanes 50 radially outward Dro. As a result, the second contact surfaces 76b of the holder 70 come into contact with the second friction surfaces 66b of the inner shrouds 60 of each of the plurality of stator vanes 50.

[0059] Suppose that the inner shroud 60 vibrates in the axial direction Da during operation of the axial flow compressor. In this case, the second friction surfaces 66b of the inner shroud 60 for each of the plurality of stator vanes 50 slide in the axial direction Da against the second contact surfaces 76b of the holder 70. Furthermore, the second elastic force receiving surfaces 67b of the inner shroud 60 for each of the plurality of stator vanes 50 slide in the axial direction Da against the second elastic bodies 80b as second friction surfaces. As the second friction surfaces 66b of the inner shroud 60 slide against the second contact surfaces 76b of the holder 70, and further as the second elastic force receiving surfaces 67b of the inner shroud 60 slide against the second elastic bodies 80b, the axial vibration of the inner shroud 60 is damped.

[0060] Furthermore, suppose that the inner shroud 60 vibrates in the circumferential direction Dc during operation of the axial flow compressor. In this case, the second friction surfaces 66b of the inner shroud 60 for each of the plurality of stator vanes 50 slide in the circumferential direction Dc against the second contact surfaces 76b of the holder 70. Furthermore, the second elastic force receiving surfaces 67b of the inner shroud 60 for each of the plurality of stator vanes 50 slide in the circumferential direction Dc as second friction surfaces against the second elastic bodies 80b for each of the plurality of stator vanes 50. As the second friction surfaces 66b of the inner shroud 60 slide against the second contact surfaces 76b of the holder 70, and further as the second elastic force receiving surfaces 67b of the inner shroud 60 slide against the second elastic bodies 80b, the circumferential vibration of the inner shroud 60 is damped.

[0061] Therefore, in this embodiment, it is possible to effectively damp vibrations of the inner shroud 60 in the radial direction Dr and the circumferential direction Dc, and also to damp vibrations in the axial direction Da.

[0062] "Third embodiment of stationary vane segment" Hereinafter, a third embodiment of the stator vane segment will be described with reference to FIG.

[0063] Like the stator vane segment VS in the first embodiment described with reference to Figure 2, the stator vane segment VS in this embodiment also comprises a plurality of stator vanes 50, a connecting plate 89, a holder, and an elastic body provided for each of the plurality of stator vanes 50.

[0064] As shown in FIG. 7, in this embodiment, the inner shroud 60c for each of the plurality of stator blades 50 includes a shroud main body plate 61, a lip base portion 63, an upstream lip portion 64u, a downstream lip portion 64d, and a central protrusion portion 65.

[0065] Like the shroud main body plate 61 in each of the above-described embodiments, the shroud main body plate 61 is provided at the end of the radially inner side Dri of the blade body 51. The shroud main body plate 61 is a plate-like member extending in the axial direction Da and the circumferential direction Dc. The shroud main body plate 61 has a gas path surface 61p facing the radially outer side Dro, a counter-gas path surface 61pa facing the radially inner side Dri and in a back-to-back relationship with the gas path surface 61p, a front surface 61f facing the axial upstream side Dau, and a rear surface 61b facing the axial downstream side Dad and in a back-to-back relationship with the front surface 61f.

[0066] The lip base portion 63 protrudes radially inward Dri from the anti-gas path surface 61pa of the shroud main body plate 61 in a range from a position Dau that is axially upstream of the center of the shroud main body plate 61 in the axial direction Da and axially downstream of the front surface 61f of the shroud main body plate 61 to a position Dau that is axially downstream of the center of the shroud main body plate 61 in the axial direction Da and axially upstream of the rear surface 61b of the shroud main body plate 61.

[0067] The upstream lip portion 64u extends toward the axial upstream side Dau from an end of the lip base portion 63 on the radially inner side Dri and on the axial upstream side Dau of the lip base portion 63. A shroud upstream groove 69u recessed toward the axial downstream side Dad is formed between the shroud main body plate 61 and the upstream lip portion 64u on the axial upstream side Dau of the lip base portion 63.

[0068] The downstream lip portion 64d extends toward the axial downstream side Dad from an end of the lip base portion 63 on the radially inner side Dri and on the axial downstream side Dad of the lip base portion 63. A shroud downstream groove 69d recessed toward the axial upstream side Dau is formed between the shroud main body plate 61 and the downstream lip portion 64d on the axial downstream side Dad of the lip base portion 63.

[0069] The central protrusion 65 protrudes from approximately the center of the lip base portion 63 in the axial direction Da toward the radially inward direction Dri.

[0070] The holder 70c has a holder bottom plate 71, an upstream base portion 73u, an upstream leg portion 72u, an upstream flange portion 74u, a downstream base portion 73d, a downstream leg portion 72d, and a downstream flange portion 74d.

[0071] The holder bottom plate 71 is a plate-like member extending in the axial direction Da and the circumferential direction Dc, similar to the holder bottom plate 71 in each of the above-described embodiments. The holder bottom plate 71 has a bottom surface 71b facing the radially outer side Dro and a seal installation surface 71s facing the radially inner side Dri and facing back-to-back with the bottom surface 71b.

[0072] The upstream base portion 73u extends from the end of the axial upstream side Dau of the holder bottom plate 71 toward the radially outer side Dro. The upstream leg portion 72u extends from the edge of the radially outer side Dro of the upstream base portion 73u toward the radially outer side Dro. The edge of the axial downstream side Dad of the upstream leg portion 72u is located on the axially upstream side Dau of the upstream base portion 73u. The upstream flange portion 74u extends from the end of the radially outer side Dro of the upstream leg portion 72u toward the axial downstream side Dad. A holder upstream groove 79u recessed toward the axial upstream side Dau is formed between the upstream base portion 73u and the upstream flange portion 74u, at the axially downstream side Dad of the upstream leg portion 72u. The upstream flange portion 74u fits into the shroud upstream groove 69u described above. Additionally, the upstream lip portion 64u of the inner shroud 60c is inserted into the holder upstream groove 79u.

[0073] The downstream base portion 73d extends radially outward from the end of the axial downstream side Dad of the holder bottom plate 71. The downstream leg portion 72d extends radially outward from the edge of the radially outward side Dro of the downstream base portion 73d. The edge of the axial upstream side Dau of the downstream leg portion 72d is located downstream of the axial downstream side Dad further than the edge of the axial upstream side Dau of the downstream base portion 73d. The downstream flange portion 74d extends radially outward from the end of the radially outward side Dro of the downstream leg portion 72d to the axial upstream side Dau. A holder downstream groove 79d recessed toward the axial downstream side Dad is formed between the downstream base portion 73d and the downstream flange portion 74d, on the axial upstream side Dau of the downstream leg portion 72d. The downstream flange portion 74d fits into the shroud downstream groove 69d described above. Additionally, the downstream lip portion 64d of the inner shroud 60c is inserted into the holder downstream groove 79d.

[0074] The downstream flange portion 74d of the holder 70c faces the axial upstream side Dau and has a first contact surface 76a extending in the radial direction Dr and the circumferential direction Dc. The downstream leg portion 62d of the inner shroud 60c faces the axial downstream side Dad and has a first friction surface 66a extending in the radial direction Dr and the circumferential direction Dc. The first contact surface 76a of the holder 70c faces the first friction surface 66a of the inner shroud 60c in the axial direction Da.

[0075] The upstream flange portion 74u of the holder 70c faces the radially inward direction Dri and has a second contact surface 76b extending in the axial direction Da and the circumferential direction Dc. The downstream flange portion 74d of the holder 70c also faces the radially inward direction Dri and has a second contact surface 76b extending in the axial direction Da and the circumferential direction Dc. The upstream lip portion 64u of the inner shroud 60c faces the radially outward direction Dro and has a second friction surface 66b extending in the axial direction Da and the circumferential direction Dc. The downstream lip portion 64d of the inner shroud 60c also faces the radially outward direction Dro and has a second friction surface 66b extending in the axial direction Da and the circumferential direction Dc. The second contact surface 76b of the upstream flange portion 74u faces the second friction surface 66b of the upstream lip portion 64u in the radial direction Dr. Additionally, the second contact surface 76b of the downstream flange portion 74d faces the second friction surface 66b of the downstream lip portion 64d in the radial direction Dr.

[0076] The upstream base portion 73u of the holder 70c has a first support surface 77a that faces the axial downstream side Dad and extends in the radial direction Dr and the circumferential direction Dc. The central protrusion 65 of the inner shroud 60c has a first elastic force receiving surface 67a that faces the axial upstream side Dau and extends in the radial direction Dr and the circumferential direction Dc. The first support surface 77a of the holder 70c is located upstream of the axial direction Dau of the first elastic force receiving surfaces 67a of each of the plurality of stator vanes 50 and faces the first elastic force receiving surfaces 67a of each of the plurality of stator vanes 50 at an interval in the axial direction Da.

[0077] A portion of the bottom surface 71b of the holder 70c, which is axially upstream of the central protrusion 65 of the inner shroud 60c, Dau, forms a second support surface 77b. This second support surface 77b faces radially outward, Dro, and extends in the axial direction Da and the circumferential direction Dc. The lip base portion 63 of the inner shroud 60c has a second elastic force receiving surface 67b, which faces radially inward, Dri, and extends in the axial direction Da and the circumferential direction Dc, in a portion axially upstream of the central protrusion 65 of the inner shroud 60c. The second support surface 77b of the holder 70c is located radially inward, Dri, of the second elastic force receiving surfaces 67b of each of the plurality of stator blades 50 and faces the second elastic force receiving surfaces 67b of each of the plurality of stator blades 50 in the radial direction Dr, with a gap therebetween.

[0078] Elastic bodies 80c are arranged between the first support surface 77a of the holder 70c and the first elastic force receiving surfaces 67a of each of the plurality of stator blades 50, and between the second support surface 77b of the holder 70c and the second elastic force receiving surfaces 67b of each of the plurality of stator blades 50, so as to generate elastic forces in the axial direction Da and the radial direction Dr. The elastic bodies 80c are C-shaped springs whose cross-sectional shape on a plane parallel to the first and second directions that are perpendicular to each other is C-shaped, and which extend in a third direction perpendicular to the first and second directions, so as to be able to generate elastic forces in the first and second directions. The elastic bodies 80c are arranged so that the third direction is the circumferential direction Dc, one of the first and second directions is the axial direction Da, and the other of the first and second directions is the radial direction Dr.

[0079] In the present embodiment, as in the first and second embodiments, the elastic bodies 80c in the holder 70c push the inner shrouds 60c of each of the plurality of stator vanes 50 toward the axial downstream side Dad. As a result, the first contact surfaces 76a of the holder 70c come into contact with the first friction surfaces 66a of the inner shrouds 60c of each of the plurality of stator vanes 50. Therefore, in the present embodiment, as in the first and second embodiments, vibrations of the inner shrouds 60c in the radial direction Dr and the circumferential direction Dc can be effectively damped. Note that in the present embodiment, the first elastic force receiving surfaces 67a of the inner shrouds 60c of each of the plurality of stator vanes 50 slide in the radial direction Dr against the elastic bodies 80c of each of the plurality of stator vanes 50 as the first friction surfaces. Therefore, the radial vibrations of the inner shrouds 60c are also damped by the sliding of the second elastic force receiving surfaces 67b of the inner shrouds 60c against the elastic bodies 80c.

[0080] In the present embodiment, furthermore, the elastic body 80c in the holder 70c presses the inner shroud 60c of each of the plurality of stator vanes 50 radially outward Dro. As a result, the second contact surface 76b of the holder 70c comes into contact with the second friction surface 66b of the inner shroud 60c of each of the plurality of stator vanes 50.

[0081] Suppose that the inner shroud 60c vibrates in the axial direction Da during operation of the axial flow compressor. In this case, the second friction surfaces 66b of the inner shrouds 60c of each of the plurality of stator vanes 50 slide in the axial direction Da against the second contact surfaces 76b of the holders 70c. Furthermore, the second elastic force receiving surfaces 67b of the inner shrouds 60c of each of the plurality of stator vanes 50 slide in the axial direction Da against the elastic bodies 80c as second friction surfaces. As the second friction surfaces 66b of the inner shrouds 60c slide against the second contact surfaces 76b of the holders 70c, and further as the second elastic force receiving surfaces 67b of the inner shrouds 60c slide against the elastic bodies 80c, the axial vibration of the inner shrouds 60c is damped.

[0082] Furthermore, suppose that the inner shroud 60c vibrates in the circumferential direction Dc during operation of the axial flow compressor. In this case, the second friction surfaces 66b of the inner shroud 60c for each of the plurality of stator vanes 50 slide in the circumferential direction Dc against the second contact surfaces 76b of the holder 70c. Furthermore, the second elastic force receiving surfaces 67b of the inner shroud 60c for each of the plurality of stator vanes 50 slide in the circumferential direction Dc against the elastic bodies 80c for each of the plurality of stator vanes 50 as second friction surfaces. As the second friction surfaces 66b of the inner shroud 60c slide against the second contact surfaces 76b of the holder 70c, and further as the second elastic force receiving surfaces 67b of the inner shroud 60c slide against the elastic bodies 80c, the circumferential vibration of the inner shroud 60c is damped.

[0083] Therefore, in this embodiment, similar to the second embodiment, it is possible to effectively damp vibrations of the inner shroud 60c in the radial direction Dr and the circumferential direction Dc, and also to damp vibrations in the axial direction Da.

[0084] The second embodiment has two types of elastic bodies 80a, 80b: a first elastic body 80a that generates an elastic force in the axial direction Da and a second elastic body 80b that generates an elastic force in the radial direction Dr. On the other hand, the present embodiment has only one type of elastic body 80c that generates elastic forces in the axial direction Da and the radial direction Dr, and is capable of damping vibrations of the inner shroud 60c in the radial direction Dr, circumferential direction Dc, and axial direction Da, as in the second embodiment. Therefore, the present embodiment has fewer parts than the second embodiment, and manufacturing costs can be reduced.

[0085] "Variations" Each of the stator vane segments VS in the above embodiments has a connecting plate 89 for connecting the outer shrouds 55 of the plurality of stator vanes 50 together. However, this connecting plate 89 may be omitted. In this case, for example, the outer shrouds 55 of the plurality of stator vanes 50 may be connected to each other by welding.

[0086] The shapes of the inner shrouds 60, 60c and the holders 70, 70c are not limited to those of the above embodiments. For example, when the inner shroud is pushed toward the axial downstream side Dad by an elastic body as in the first embodiment, the inner shroud may have an elastic force receiving surface (or a first elastic force receiving surface) facing the axial upstream side Dau and a friction surface (or a first friction surface) facing the axial upstream side Dau and extending at least in the radial direction Dr, and the holder may have a support surface (or a first support surface) facing the elastic force receiving surface (or the first elastic force receiving surface) in the axial direction Da and a contact surface (or a first contact surface) facing the friction surface (or the first friction surface) in the axial direction Da. Furthermore, for example, in the second and third embodiments, when an elastic body is used to push the inner shroud toward the axial downstream side Dad and toward the radially outer side Dro, the inner shroud may have a first elastic force receiving surface, a second elastic force receiving surface, a first friction surface, and a second friction surface, and the holder may have a first support surface, a second support surface, a first contact surface, and a second contact surface.

[0087] The elastic body 80a in the first embodiment and the first elastic body 80a in the second embodiment are not limited to the plurality of disc springs 81. The elastic body 80a may be, for example, a coil spring. The second elastic body 80b in the second embodiment is not limited to a leaf spring. The elastic body 80b may be, for example, a coil spring, a C-shaped spring, an E-shaped spring. The elastic body 80c in the third embodiment is not limited to a C-shaped spring. The elastic body 80c may be, for example, an E-shaped spring. An E-shaped spring is a spring whose cross-sectional shape on a plane parallel to a first direction and a second direction perpendicular to each other is E-shaped, which extends in a third direction perpendicular to the first direction and the second direction, and which is capable of generating elastic forces in the first direction and the second direction.

[0088] Furthermore, the present disclosure is not limited to the embodiments described above, and various additions, modifications, substitutions, partial deletions, etc. are possible within the scope of the conceptual idea and spirit of the present invention as derived from the content defined in the claims and their equivalents.

[0089] "Addendum" The vane segments VS in the above-described embodiment and modified examples can be understood, for example, as follows.

[0090] (1) The stator vane segment VS in the first embodiment is The stator vane 50 includes a stator vane 50, a holder 70, 70c that holds a portion of the stator vane 50, and elastic bodies 80a, 80c that are disposed within the holder 70, 70c. The stator vane 50 includes a blade body 51 having an airfoil-shaped cross section perpendicular to a radial direction Dr relative to the axis Ar, and inner shrouds 60, 60c that are provided at ends of the blade body 51 in the radial direction Dr. The blade body 51 has an axial upstream side Dau and an axial downstream side Dad in the axial direction Da in which the axis Ar extends, and has a leading edge 51f on the axially most upstream side Dau in the blade body 51 and a trailing edge 51b on the axially most downstream side Dad in the blade body 51. The inner shrouds 60, 60c have an elastic force receiving surface 67a facing the axial upstream side Dau and a friction surface 66a facing the axial upstream side Dau and extending in the radial direction Dr. The holders 70, 70c are configured to cover a portion of the inner shroud 60, 60c. The holders 70, 70c have a support surface 77a located upstream of the elastic force receiving surface 67a in the axial direction Da and facing the elastic force receiving surface 67a at a distance. The elastic bodies 80a, 80c are arranged so that an elastic force is generated in the axial direction Da between the elastic force receiving surface 67a of the inner shroud 60, 60c and the support surface 77a of the holders 70, 70c. The friction surface 66a of the inner shroud 60, 60c is in contact with a portion of the holders 70, 70c or a portion of the elastic bodies 80a, 80c.

[0091] In this embodiment, the elastic bodies 80a, 80c in the holders 70, 70c push the inner shrouds 60, 60c toward the axial downstream side Dad, causing parts of the holders 70, 70c or parts of the elastic bodies 80a, 80c to come into contact with the friction surfaces 66a of the inner shrouds 60, 60c.

[0092] Suppose that the inner shrouds 60, 60c vibrate in the radial direction Dr during operation of the axial flow compressor. In this case, in this embodiment, the friction surfaces 66a of the inner shrouds 60, 60c slide in the radial direction Dr against parts of the holders 70, 70c or parts of the elastic bodies 80a, 80c. In this embodiment, the friction surfaces 66a of the inner shrouds 60, 60c slide against parts of the holders 70, 70c or parts of the elastic bodies 80a, 80c, thereby damping the radial vibration of the inner shrouds 60, 60c.

[0093] During operation of the axial compressor, gas that flows into the casing of the axial compressor is sent to the axial downstream side Dad. The pressure of this gas gradually increases as it is sent to the axial downstream side Dad. For this reason, during operation of the axial compressor, a force P acts on the stator vane segment VS from the axial downstream side Dad of the stator vane segment VS toward the axial upstream side Dau. In the stator vane segment VS, the stator vane 50 is fixed to the compressor casing 25, but the holders 70, 70c are not fixed to the compressor casing 25. For this reason, the force P from the gas acts as a force that pushes the holders 70, 70c toward the axial upstream side Dau relative to the stator vane 50.

[0094] Suppose that a spring is disposed inside the holder so that the spring can press the inner shroud toward the axial upstream side Dau, as in the technology described in Patent Document 1 described in the Background Art section. In this case, the elastic force of the spring is canceled out by the force from the gas that presses the holder toward the axial upstream side Dau relative to the stator vane. As a result, the force in the direction of contact between the friction surface of the inner shroud and the contact surface of the holder weakens, or this force disappears depending on the operating state of the axial flow compressor. Therefore, in this case, the vibration damping effect achieved by providing the spring is reduced.

[0095] On the other hand, in this embodiment, the elastic bodies 80a, 80c are disposed inside the holders 70, 70c so that the elastic bodies 80a, 80c can press the inner shrouds 60, 60c toward the axial downstream side Dad. In this case, the force P from the gas and the elastic force of the spring, which press the holders 70, 70c toward the axial upstream side Dau relative to the stator vane 50, both act in directions that bring the friction surfaces 66a of the inner shrouds 60, 60c into contact with the contact surfaces 76a of the holders 70, 70c. Therefore, in this embodiment, vibrations of the inner shrouds 60, 60c in the radial direction Dr can be effectively damped.

[0096] (2) The stationary vane segment VS in the second embodiment is In the stator vane segment VS of the axial flow compressor in the first embodiment, the friction surface 66a of the inner shrouds 60, 60c extends in the radial direction Dr and in the circumferential direction Dc relative to the axis Ar.

[0097] Suppose that the inner shrouds 60, 60c vibrate in the circumferential direction Dc during operation of the axial flow compressor. In this case, in this embodiment, the friction surfaces 66a of the inner shrouds 60, 60c slide in the radial direction Dr against parts of the holders 70, 70c or parts of the elastic bodies 80a, 80c. In this embodiment, the friction surfaces 66a of the inner shrouds 60, 60c slide against parts of the holders 70, 70c or parts of the elastic bodies 80a, 80c, thereby damping the circumferential vibration of the inner shrouds 60, 60c.

[0098] (3) The stationary vane segment VS in the third embodiment is In the stator vane segment VS of the axial compressor in the first or second aspect, the holder 70, 70c has a contact surface 76a that extends in the radial direction Dr and in the circumferential direction Dc relative to the axis Ar and that is in contact with the friction surface 66a of the inner shroud 60, 60c.

[0099] Suppose that the inner shrouds 60, 60c vibrate in the radial direction Dr and / or the circumferential direction Dc during operation of the axial flow compressor. In this case, in this aspect, the friction surfaces 66a of the inner shrouds 60, 60c slide against the contact surfaces 76a of the holders 70, 70c in the radial direction Dr and / or the circumferential direction Dc. In this aspect, the friction surfaces 66a of the inner shrouds 60, 60c slide against the contact surfaces 76a of the holders 70, 70c, thereby damping the radial vibrations and / or circumferential vibrations of the inner shrouds 60, 60c.

[0100] (4) The stator vane segment VS in the fourth aspect is The stator vane segment VS of the axial compressor according to the first aspect or the second aspect includes a second elastic body 80b in addition to the first elastic body 80a that is the elastic body 80a. The inner shroud 60 includes, in addition to the first elastic force receiving surface 67a that is the elastic force receiving surface 67a, a second elastic force receiving surface 67b that faces the radially inner side Dri of the radially inner side Dri and the radially outer side Dro in the radial direction Dr, and in addition to the first friction surface 66a that is the friction surface 66a, a second friction surface 66b that faces the radially inner side Dri and extends in the axial direction Da. The holder 70 includes, in addition to the first support surface 77a that is the support surface 77a, a second support surface 77b that is located radially inner than the second elastic force receiving surface 67b in the radial direction Dr and faces the second elastic force receiving surface 67b at an interval in the radial direction Dr. The second elastic body 80b is disposed so that an elastic force is generated in the radial direction Dr between the second elastic force receiving surface 67b of the inner shroud 60 and the second support surface 77b of the holder 70. The second friction surface 66b of the inner shroud 60 is in contact with a part of the holder 70 or a part of the second elastic body 80b.

[0101] In this embodiment, the first elastic body 80a in the holder 70 presses the inner shroud 60 toward the axial downstream side Dad, and the second elastic body 80b in the holder 70 presses the inner shroud 60 toward the radially outward side Dro. As a result, a part of the holder 70 or a part of the first elastic body 80a contacts the first friction surface 66a of the inner shroud 60, and another part of the holder 70 or another part of the second elastic body 80b contacts the second friction surface 66b of the inner shroud 60.

[0102] As described above, in this embodiment, as in the first embodiment, a part of the holder 70 or a part of the first elastic body 80a comes into contact with the first friction surface 66a that faces the axial upstream side Dau and extends in the radial direction Dr, and therefore, vibrations of the inner shroud 60 in the radial direction Dr can be effectively damped.

[0103] Furthermore, suppose that the inner shroud 60 vibrates in the axial direction Da during operation of the axial flow compressor. In this case, in this embodiment, the second friction surface 66b of the inner shroud 60 slides in the axial direction Da against another part of the holder 70 or a part of the second elastic body 80b. In this embodiment, the second friction surface 66b of the inner shroud 60 slides against a part of the holder 70 or a part of the second elastic body 80b, thereby damping the axial vibration of the inner shroud 60.

[0104] (5) The stator vane segment VS in the fifth aspect is In the stator vane segment VS of the axial compressor according to the first or second aspect, the inner shroud 60c has, in addition to the first elastic force receiving surface 67a which is the elastic force receiving surface 67a, a second elastic force receiving surface 67b which faces the radially inner side Dri of the radially inner side Dri and the radially outer side Dro in the radial direction Dr, and, in addition to the first friction surface 66a which is the friction surface 66a, a second friction surface 66b which faces the radially inner side Dri and extends in the axial direction Da. The holder 70c has, in addition to the first support surface 77a which is the support surface 77a, a second support surface 77b which is located radially inner side Dri than the second elastic force receiving surface 67b and faces the second elastic force receiving surface 67b in the radial direction Dr. The second elastic force receiving surface 67b and the second support surface 77b are both located between the first elastic force receiving surface 67a and the first support surface 77a in the axial direction Da. The elastic body 80c is arranged so that elastic forces are generated in the axial direction Da and the radial direction Dr between the first elastic force receiving surface 67a and the first support surface 77a and between the second elastic force receiving surface 67b and the second support surface 77b. The first friction surface 66a of the inner shroud 60c contacts a portion of the holder 70c or a portion of the elastic body 80c, and the second friction surface 66b of the inner shroud 60c contacts a portion of the holder 70c or a portion of the elastic body 80c.

[0105] In this embodiment, the elastic body 80c in the holder 70c pushes the inner shroud 60c toward the axial downstream side Dad and toward the radially outward side Dro. As a result, in this embodiment, a part of the holder 70c or a part of the elastic body 80c contacts the first friction surface 66a of the inner shroud 60c, and another part of the holder 70c or a part of the elastic body 80c contacts the second friction surface 66b of the inner shroud 60c.

[0106] As described above, in this embodiment, as in the first embodiment, a part of the holder 70c or a part of the elastic body 80c contacts the first friction surface 66a that faces the axial upstream side Dau and extends in the radial direction Dr, and therefore, vibrations of the inner shroud 60c in the radial direction Dr can be effectively damped.

[0107] Furthermore, suppose that the inner shroud 60c vibrates in the axial direction Da during operation of the axial flow compressor. In this case, in this embodiment, the second friction surface 66b of the inner shroud 60c slides in the axial direction Da against another part of the holder 70c or another part of the elastic body 80c. In this embodiment, the second friction surface 66b of the inner shroud 60c slides against another part of the holder 70c or another part of the elastic body 80c, thereby damping the axial vibration of the inner shroud 60c.

[0108] The axial flow compressors in the above-described embodiments and modifications can be understood, for example, as follows. (6) In a sixth aspect, the axial flow compressor comprises: The compressor includes a stator vane segment VS of an axial flow compressor in any one of the first to fifth embodiments, a compressor rotor 21 that can rotate around the axis Ar, and a compressor casing 25 that covers the stator vane segment VS and the compressor rotor 21 and to which the stator vane segment VS is attached. [Explanation of symbols]

[0109] 10: Gas turbine 11: Gas turbine rotor 15: Gas turbine casing 16: Intermediate casing 20: Compressor 21: Compressor rotor 22: Rotor shaft 23: Moving blade row 24: Stator blade row 25: Compressor casing 30: Combustor 40: Turbine 41: Turbine rotor 42: Rotor shaft 43: Moving blade row 44: Stator blade row 45: Turbine casing 50: Stator blade 51: Wing body 51f: leading edge 51b: Trailing edge 55: Outer shroud 59: Gas flow path 60,60c: Inner shroud 61: Shroud body plate 61p: Gaspath surface 61pa: Anti-gas pass surface 61f:Front 61b: Rear 62u: Upstream leg 62d: Downstream leg 63: Lip base 64u: Upstream lip 64d: Downstream lip 65: Central protrusion 66a: Friction surface (first friction surface) 66b: Second friction surface 67a: Elastic force receiving surface (first elastic force receiving surface) 67b: Second elastic force receiving surface 69u: Shroud upstream gutter 69d: Shroud downstream groove 70,70c:Holder 71: Holder bottom plate 71b: Bottom 71s: Seal installation surface 72u: Upstream leg 72d: Downstream leg 73u: Upstream base section 73d: Downstream base section 74u: Upstream flange 74d: Downstream flange 76a: Contact surface (first contact surface) 76b: Second contact surface 77a: Support surface (first support surface) 77b:Second support surface 78: Seal 79u: Holder upstream groove 79d: Holder downstream groove 80a: Elastic body (first elastic body) 80b: Second elastic body 80c: Elastic body 81: Disc spring 82: Spacer 89: Connecting plate VS: Stator vane segment A: Air (or gas) G: Combustion gas F:Fuel P: Power Ar: Axis line Da: Axial direction Dau: Axis upstream side Dad: Downstream of the axis Dc: Circumferential direction Dr: Radial direction Dri: Radial inner direction Dro: Radial outer side

Claims

1. Stator blades and a holder that holds a portion of the stator blade; an elastic body disposed within the holder; Equipped with The stator vane includes a blade body having an airfoil shape in a cross section perpendicular to a radial direction relative to an axis, and an inner shroud provided at an end of the blade body in the radial direction, The blade body has an axially upstream side and an axially downstream side in the axial direction in which the axis extends, and has a leading edge that is the axially most upstream side of the blade body and a trailing edge that is the axially most downstream side of the blade body, the inner shroud has an elastic force receiving surface facing the upstream side of the axis and a friction surface facing the upstream side of the axis and extending in the radial direction, the holder is configured to cover a portion of the inner shroud; the holder has a support surface located upstream of the elastic force receiving surface in the axial direction and facing the elastic force receiving surface with a gap therebetween in the axial direction, the elastic body is disposed between the elastic force receiving surface of the inner shroud and the support surface of the holder so that an elastic force is generated in the axial direction, the friction surface of the inner shroud is in contact with a part of the holder or a part of the elastic body. Axial compressor stator vane segment.

2. 2. The stator vane segment of an axial flow compressor according to claim 1, The friction surface of the inner shroud extends in the radial direction and in a circumferential direction relative to the axis. Axial compressor stator vane segment.

3. 2. The stator vane segment of an axial flow compressor according to claim 1, the holder has a contact surface that extends in the radial direction and in a circumferential direction relative to the axis and that contacts the friction surface of the inner shroud. Axial compressor stator vane segment.

4. 2. The stator vane segment of an axial flow compressor according to claim 1, In addition to the first elastic body, a second elastic body is provided, the inner shroud has, in addition to the first elastic force receiving surface that is the elastic force receiving surface, a second elastic force receiving surface that faces the radially inner side out of the radially inner side and the radially outer side in the radial direction, and, in addition to the first friction surface that is the friction surface, a second friction surface that faces the radially inner side and extends in the axial direction, the holder has, in addition to the first support surface that is the support surface, a second support surface that is located radially inward of the second elastic force receiving surface and faces the second elastic force receiving surface with a gap in the radial direction, the second elastic body is disposed between the second elastic force receiving surface of the inner shroud and the second support surface of the holder so that an elastic force is generated in the radial direction, the second friction surface of the inner shroud is in contact with a part of the holder or a part of the second elastic body. Axial compressor stator vane segment.

5. 2. The stator vane segment of an axial flow compressor according to claim 1, the inner shroud has, in addition to the first elastic force receiving surface that is the elastic force receiving surface, a second elastic force receiving surface that faces the radially inner side out of the radially inner side and the radially outer side in the radial direction, and, in addition to the first friction surface that is the friction surface, a second friction surface that faces the radially inner side and extends in the axial direction, the holder has, in addition to the first support surface that is the support surface, a second support surface that is located radially inward of the second elastic force receiving surface and faces the second elastic force receiving surface in the radial direction, the second elastic force receiving surface and the second support surface are both located between the first elastic force receiving surface and the first support surface in the axial direction, the elastic body is arranged so that elastic forces are generated in the axial direction and the radial direction between the first elastic force receiving surface and the first support surface and between the second elastic force receiving surface and the second support surface, the first friction surface of the inner shroud contacts a part of the holder or a part of the elastic body, and the second friction surface of the inner shroud contacts a part of the holder or a part of the elastic body. Axial compressor stator vane segment.

6. A stator vane segment for an axial flow compressor according to claim 1; a compressor rotor rotatable about the axis; a compressor casing that covers the stator vane segments and the compressor rotor and to which the stator vane segments are attached; An axial flow compressor comprising:

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