Guide vane segment and steam turbine with such a segment

Abstract

Guide vane segment (30) of a steam turbine, wherein the guide vane segment (30) comprises the following: a paddle ring (70) extending circumferentially (Dc) with respect to an axis (Ar); a plurality of guide vanes (33) mounted on an inner side (Dri) in the radial direction with respect to the axis (Ar) of the blade ring (70) and aligned in the circumferential direction (Dc); and a rapping element (90) configured to limit the relative movement of the plurality of guide vanes (33) with respect to the blade ring (70), wherein Each of the plurality of guide vanes (33) forms a blade shape and includes a blade body (35) extending in the radial direction (Dr) with respect to the axis (Ar) and an outer shell (50) formed on an outer surface (Dro) in the radial direction (Dr) of the blade body (35) with respect to the axis (Ar), the outer shell (50) includes a first end surface (51uo), a second end surface (51d), an outer circumferential surface (53) and an engagement groove (56), the first end surface (51uo) of an upstream side (Dau) faces in the axial direction (Da) in which the axis (Ar) extends, the second end face (51d) of a downstream side (Dad) is facing the upstream side (Dau) in the axial direction (Da), the outer circumferential surface (53) faces the outer surface (Dro) in the radial direction and connects an end on the outer surface (Dro) of the first end surface (51uo) in the radial direction and an end on the outer surface (Dro) of the second end surface (51d) in the radial direction, the engagement groove (56) is recessed from the second end surface (51d) to the upstream side (Dau) and extends in the circumferential direction (Dc), the blade ring (70) includes a gas path surface (43), a blade ring groove (73) and a storage chamber formation section (81), the gas path surface (43) faces the inside (Dri) in the radial direction and extends in the circumferential direction (Dc), the blade ring groove (73) is recessed radially from the gas path surface (43) towards the outside (Dro) and extends circumferentially (Dc), into which each of the outer shells (50) of the plurality of guide vanes (33) enters, the storage space formation section (81) includes a surface that forms a storage space (87) which interacts with the outer shells (50) of the plurality of guide vanes (33) into which the crimping element (90) enters and opens in the radial direction of the inside (Dri), the blade ring groove (73) includes a first groove side surface (74u), a second groove side surface (74d), a groove bottom surface (75) and a convex section (76), the first groove side surface (74u) of the downstream side (Dad) is facing, extends in the circumferential direction (Dc) and faces each of the first end surfaces (51uo) of the outer shells (50) of the plurality of guide vanes (33), the second groove side surface (74d) is facing the upstream side (Dau), extends in the circumferential direction (Dc) and is facing each of the second end surfaces (51d) of the outer shells (50) of the plurality of guide vanes (33), the groove bottom surface (75) of the inner side (Dri) faces radially, extends circumferentially (Dc), connects the first groove side surface (74u) and the second groove side surface (74d), and each of the outer circumferential surfaces (53) of the outer shells (50) faces the plurality of guide vanes (33), the convex section (76) protrudes from the second groove side surface (74d) to the upstream side (Dau), extends in the circumferential direction (Dc) and fits into each of the engagement grooves (56) of the outer shells (50) in the plurality of guide vanes (33), the storage space formation section (81) is connected in a radial direction to one end on the inside (Dri) of the first groove side surface (74u), and the crimping element (90) extends in the circumferential direction (Dc), is housed in the storage space (87), contacts the surface of the storage space formation section (81), each of the outer shells (50) of the plurality of guide vanes (33) is contacted and is exposed from the opening (88i) of the storage space (87).

Description

Technical area

[0001] The present invention relates to a guide vane segment having a plurality of guide vanes and a steam turbine having the guide vane segment. State of the art

[0002] A steam turbine includes a rotor rotating about a rotational axis, a casing covering the rotor, and a plurality of guide vane segments. The rotor includes a rotor shaft extending axially parallel to the rotational axis, and a plurality of rotor blade rows fixed to the outer periphery of the rotor shaft and aligned in the axial direction. Each of the rotor blade rows includes a plurality of rotor blades aligned in the circumferential direction with respect to the rotational axis. Guide vane rows are arranged at a position upstream of each of the rotor blade rows. Each guide vane row includes a plurality of guide vanes aligned in the circumferential direction. The guide vane segment includes a blade ring extending in the circumferential direction and a plurality of guide vanes arranged on the inner side in the radial direction of the blade ring.The vane ring is formed with vane ring grooves that extend radially from the inside to the outside and extend in the circumferential direction. Outer shells of the plurality of guide vanes fit into the vane ring grooves of the vane ring. This vane ring is attached to a portion of the inside of the casing in the radial direction.

[0003] Specific structures of this vane segment are disclosed, for example, in JP 2007-107467 A. The vane ring grooves of the vane segment include a pair of groove side surfaces facing each other in the axial direction, a groove bottom surface connecting ends on the outer side of the pair of groove side surfaces in the radial direction, and a convex portion protruding from each of the pair of groove side surfaces. An engagement groove is formed on the outer shell of the vane and enters the convex portion of the vane ring groove. A leaf spring is disposed between the groove bottom surface of the vane ring groove and the outer peripheral surface of the outer shell on the vane.

[0004] In this guide vane segment, the connectivity between the convex portion of the blade ring groove and the engagement groove of the outer shell is improved by pressing the outer shell within the blade ring groove inward in the radial direction by the leaf spring in the blade ring groove.

[0005] US 2017 / 0 292 391 A1 relates to a steam turbine drum nozzle, the drum nozzle comprising: an airfoil; a radially inner sidewall coupled to a first end of the airfoil; and a radially outer sidewall coupled to a second end of the airfoil, the second end being opposite the first end.The radially outer sidewall comprises: a first portion radially outward of the airfoil; a thinned portion coupled to the first portion; and a second portion coupled to the thinned portion radially outward of the airfoil, the second portion having a radially outer surface and a circumferentially facing side abutting the radially outer surface, the second portion including a circumferentially extending slot, and the second portion including a relief slot extending from the circumferentially extending side into a body of the second portion. A wedge member may be disposed in a circumferentially extending slot to retain the drum nozzle in the circumferentially extending slot.

[0006] US 4,900,223 A describes a steam turbine having an outer blade ring supporting a row of stationary blades and an adjacent downstream row of long rotatable blades. The outer blade ring has a generally conical flow-guiding surface for directing steam outwardly as it flows through the row of stationary blades. The outer blade ring is supported by a radially adjacent support ring having a flow-guiding surface axially adjacent to and extending outwardly from the flow-guiding surface of the outer blade ring. Brief description of the inventionTechnical problem

[0007] In the vane segment described in JP 2007-107467 A, each time the outer shell of a vane is inserted into the vane ring groove of the vane ring, a jig or the like must be used to compress the leaf spring. As a result, there is a problem that the assembly time for the vane segment increases. This vane segment also has the problem that the vanes rattle against the vane ring in a relationship where the vanes are pushed radially inward by the leaf springs. This tendency becomes particularly pronounced as the leaf springs deteriorate.

[0008] Therefore, it is an object of the present invention to provide a guide vane segment and a steam turbine with the guide vane segment, which can securely attach the guide vanes to a blade ring and reduce assembly times. Solution to the problem

[0009] One aspect of the present invention for solving the above-described problem is a vane segment having the features of claim 1, comprising a vane ring extending in the circumferential direction with respect to an axis, a plurality of vanes fixed on an inner side in the radial direction with respect to the axis of the vane ring and aligned in the circumferential direction, and a caulking member configured to limit the relative movement of the plurality of vanes with respect to the vane ring. Each of the plurality of vanes forms a vane shape and includes a vane body extending in the radial direction with respect to the axis and an outer shell formed on an outer side in the radial direction of the vane body with respect to the axis. The outer shell includes a first end surface, a second end surface, an outer peripheral surface, and an engagement groove.The first end surface faces an upstream side in the axial direction in which the axis extends. The second end surface faces a downstream side opposite the upstream side in the axial direction. The outer peripheral surface faces the outer side in the radial direction and connects one end on the outer side of the first end surface in the radial direction and one end on the outer side of the second end surface in the radial direction. The engagement groove is recessed from the second end surface to the upstream side and extends in the circumferential direction. The blade ring includes a gas path surface, a blade ring groove, and a bearing space forming portion. The gas path surface faces the inner side in the radial direction and extends in the circumferential direction.The vane ring groove is recessed from the gas path surface toward the outer side in the radial direction and extends in the circumferential direction into which each of the outer shells of the plurality of guide vanes enters. The bearing space forming portion includes a surface that forms a bearing space that cooperates with the outer shells of the plurality of guide vanes, into which the caulking member enters and opens in the radial direction of the inner side. The vane ring groove includes a first groove side surface, a second groove side surface, a groove bottom surface, and a convex portion. The first groove side surface faces the downstream side, extends in the circumferential direction, and faces each of the first end surfaces of the outer shells of the plurality of guide vanes.The second groove side surface faces the upstream side, extends in the circumferential direction, and faces each of the second end surfaces of the outer shells of the plurality of guide vanes. The groove bottom surface faces the inner side in the radial direction, extends in the circumferential direction, connects the first groove side surface and the second groove side surface, and faces each of the outer peripheral surfaces of the outer shells of the plurality of guide vanes. The convex portion protrudes from the second groove side surface toward the upstream side, extends in the circumferential direction, and fits into each of the engaging grooves of the outer shells in the plurality of guide vanes. The bearing space forming portion is connected to one end on the inner side of the first groove side surface in the radial direction.The caulking member extends in the circumferential direction, is housed in the bearing space, contacts the surface of the bearing space forming portion, contacts each of the outer shells of the plurality of guide vanes, and is exposed from the opening of the bearing space.

[0010] In the present aspect, in the portion on the second side of the outer shell, the convex portion of the blade ring groove fits into the engagement groove of the outer shell, and the relative movement in the radial direction with respect to the blade ring of the outer shell is restricted. In the portion on the first side of the outer shell, the caulking member housed in the bearing space contacts the surface of the outer shell and the surface of the blade ring, which form the bearing space, and the relative movement in the radial direction with respect to the blade ring of the outer shell is restricted. Thus, in the present aspect, the guide vanes can be securely fixed to the blade ring.

[0011] In assembling the vane segment of the present aspect, first, a plurality of outer shells are arranged in the vane ring groove, and a caulking member is arranged in the bearing space. Next, a portion of the caulking member exposed from the opening of the bearing space, the portion adjacent to the outer shells of the plurality of vanes aligned in the circumferential direction, is hammered with a tool such as a hammer. Thus, in the present aspect, each time the outer shell of a vane is inserted into the vane ring groove, the process of inserting the caulking member and hammering the caulking member, and the process of compressing the leaf spring using a jig or the like, as in the technique described in JP 2007-107467 A, can be omitted.Thus, in this respect, it is possible to reduce the working hours for the assembly of the guide vane segments.

[0012] In the vane segment, the outer shell may include a contact inner circumferential surface facing the inner side in the radial direction and extending radially from an end on the inner side of the first end surface to the downstream side, and the storage space forming portion may include a space bottom surface and a space side surface. The space bottom surface faces the inner side in the radial direction, extends circumferentially, and extends radially from an end on the inner side of the first groove side surface to the upstream side. The space side surface is arranged on the inner side in the radial direction from the space bottom surface, faces the downstream side, and extends in the radial and circumferential directions. An end on the inner side of the space side surface in the radial direction forms part of a rim on the opening of the storage space.The caulking member contacts the chamber bottom surface and the chamber side surface and contacts each of the contact inner peripheral surfaces of the outer shells of the plurality of guide vanes.

[0013] In the present aspect, the caulking member accommodated in the bearing space contacts the space bottom surface and the space side surface of the blade ring in the portion on the first side of the outer shell, and contacts the contact inner peripheral surfaces of the outer shell of the plurality of guide vanes. Therefore, in the present aspect, in the portion on the first side of the outer shell, the outer shell is not relatively movable in the radial direction with respect to the blade ring.

[0014] In the guide vane segment in which the storage space forming portion includes the space base surface, the storage space forming portion may include a space back surface and a space bottom facing surface. The space back surface faces the downstream side, extends in the circumferential direction, and extends from one end on the upstream side of the space bottom surface to the inner side in the radial direction. The space bottom facing surface faces the outer side in the radial direction, extends in the circumferential direction, extends from one end on the inner side of the space back surface to the second side in the radial direction, and faces the space bottom surface in the radial direction. The space side surface extends from one end on the downstream side of the space bottom facing surface to the inner side in the radial direction, and a cross-sectional shape of the storage space on a plane perpendicular to the circumferential direction forms an L-shape.A cross-sectional shape of the caulking element in the plane perpendicular to the circumferential direction forms an L-shape to fit into the bearing space.

[0015] In the present aspect, since the cross-sectional shape of the storage space forms an L-shape and the cross-sectional shape of the caulking member accommodated in the storage space also forms an L-shape, it is possible to prevent the caulking member from loosening and slipping out of the storage space.

[0016] In each of the above-described guide vane segments, one end of both ends of the blade body in the axial direction may form a leading edge, another end may form a trailing edge, the leading edge may be provided on the upstream side in the axial direction with respect to the trailing edge, and the trailing edge may be provided on the downstream side in the axial direction with respect to the leading edge.

[0017] A force toward the downstream axial side acts on the vane body of the guide vanes due to steam. In the present aspect, the caulking element is arranged on the upstream axial side, the outer shell of the guide vane. Thus, in the present aspect, it is possible to minimize the deformation of the caulking element due to the guide vanes being subjected to a force toward the downstream axial side.

[0018] In any of the above-described guide vane segments in which the storage space forming portion includes the space bottom surface, one end of both ends of the blade body in the axial direction may form a leading edge, another end may form a trailing edge, the leading edge may be provided on the upstream side in the axial direction with respect to the trailing edge, the trailing edge may be provided on the downstream side in the axial direction with respect to the leading edge, and the space bottom surface of the blade ring may be provided on the inner side in the radial direction from the convex portion of the blade ring.

[0019] The outer side portion of the guide vane in the radial direction is supported by the blade ring, and the inner side portion in the radial direction is a free end. Therefore, when a force is applied to the blade body of the guide vane on the downstream axial side by steam, a moment is exerted on the guide vane by which the inner side portion of the guide vane is to rotate in the radial direction based on the outer side portion of the guide vane. In other words, a moment is exerted on the guide vane by which the upstream axial side portion of the outer shell is to move toward the inner side in the radial direction, and the downstream axial side portion of the outer shell is to move toward the outer side in the radial direction.In the present aspect, the caulking member that restricts the radial movement of the portion on the upstream axial side of the outer shell is disposed on the inner side of the radial direction from the convex portion of the blade ring groove that restricts the radial movement of the portion on the downstream axial side of the outer shell. Therefore, in the present aspect, a moment acting on the guide vane can be effectively counteracted.

[0020] In any of the above-described guide vane segments in which the bearing space forming portion includes the space bottom surface, a distance in the radial direction from the groove bottom surface to the space bottom surface of the blade ring may correspond to the distance in the radial direction from the outer peripheral surface of the outer shell to the contact inner peripheral surface of the outer shell.

[0021] In the present aspect, when the outer shell is housed in the blade ring groove, the space bottom surface of the blade ring and the contact inner peripheral surface of the outer shell are substantially in the same plane. This allows the caulking member surface to be made to contact the space bottom surface of the blade ring and the contact inner peripheral surface of the outer shell in the same plane, and the shape of the caulking member can be simplified.

[0022] Any of the vane segments described above may include a first limiting member configured to limit relative circumferential movement with respect to the vane ring of the outer shell of a vane located closest to one circumferential side among the plurality of vanes aligned in the circumferential direction; and a second limiting member configured to limit relative circumferential movement with respect to the vane ring of the outer shell of a vane located closest to the other circumferential side among the plurality of vanes aligned in the circumferential direction.

[0023] In one aspect of the present invention to solve the above-described problem, a steam turbine includes any of the above-described vane segments, a rotor configured to rotate about the axis, and a casing configured to cover the vane segments and the rotor. Advantageous effect of the invention

[0024] With the guide vane segments according to one aspect of the present invention, it is possible to securely attach the guide vanes to the blade ring, thereby reducing assembly time. Brief description of the drawings Fig. 1 is a schematic cross-sectional diagram illustrating a steam turbine according to an embodiment of the present invention. Fig. 2 is a perspective diagram of a vane segment according to an embodiment of the present invention. Fig. 3 is a diagram indicated by an arrow III in Fig. 2 is viewed from. Fig. 4 is a cross-sectional view taken along a line IV-IV in Fig. 2. Fig. 5 is a cross-sectional diagram of a vane segment around a set screw according to an embodiment of the present invention. Fig. 6 is an exploded perspective view of the vane segment according to the embodiment of the present invention. Fig. 7 is a cross-sectional diagram of the main portions of the vane segment before plastic deformation of a caulking member according to the embodiment of the present invention. Fig. 8 is a cross-sectional diagram of the main portions of the vane segment after plastic deformation of the caulking member according to the embodiment of the present invention. Description of embodiments

[0025] In the following, an embodiment of a steam turbine according to the present invention will be described with reference to the Fig. 1 to 8 are described in detail.

[0026] As in Fig. 1, a steam turbine of the present embodiment includes a rotor 10 rotating around an axis Ar, a casing 20 covering an outer peripheral side of the rotor 10, a guide vane assembly BA, an axial seal device 25, and a bearing 26. Note that hereinafter, a direction in which the axis Ar extends is referred to as an axial direction Da, a circumferential direction around this axis Ar is simply referred to as a circumferential direction Dc, and a direction orthogonal to the axis Ar is referred to as a radial direction Dr. In addition, one side in the axial direction Da is referred to as an upstream axial side (first side) Dau, and the other side in the axial direction Da is referred to as a downstream axial side (second side) Dad. The direction to the axis Ar in the radial direction Dr is referred to as an inner side Dri in the radial direction, and the opposite direction is referred to as an outer side Dro in the radial direction.

[0027] The rotor 10 includes a rotor shaft 11 centered around the axis Ar and extending in the axial direction Da, and a plurality of rotor blade rows 12 attached to this rotor shaft 11. The plurality of rotor blade rows 12 are aligned in the axial direction Da. Each of the rotor blade rows 12 includes a plurality of rotor blades 13 aligned in the circumferential direction Dc.

[0028] The guide vane assembly BA extends annularly around the axis Ar. The guide vane assembly BA includes a plurality of guide vane rows 32. Each of the guide vane rows 32 is arranged on the upstream axial side Dau of the rotor blade row 12 of any one of the plurality of rotor blade rows 12. Each of the guide vane rows 32 includes a plurality of guide vanes 33 arranged in the circumferential direction Dc. The annular guide vane assembly BA consists of a plurality of guide vane segments 30 aligned in the circumferential direction Dc. In other words, the annular guide vane assembly BA can be divided into a plurality of guide vane segments 30 for ease of assembly or the like.

[0029] The vane segments 30 include a vane ring 70 extending in the circumferential direction Dc, a plurality of vanes 33 mounted on the inner side of the vane ring 70 in the radial direction Dri and aligned in the circumferential direction Dc, and a seal ring 60 disposed on the inner side Dri of the plurality of vanes 33 in the radial direction. The annular space between the inner side Dri of the vane ring 70 in the radial direction and the outer side Dro of the rotor shaft 11 in the radial direction forms a steam flow path 19 through which steam S flows.

[0030] The casing 20 covers the rotor 10 and the guide vane segments 30. The casing 20 is formed with an inlet 21 that directs the steam S inward and an outlet 22 that discharges the steam S outward. The inlet 21 is located on the upstream axial side Dau of the outlet 22. A portion of the rotor shaft 11 penetrates the casing 20. The shaft sealing device 25 is arranged on a portion of the casing 20 into which the rotor shaft 11 penetrates. The bearing 26 rotatably supports both ends of the rotor shaft 11. The blade ring 70 of the guide vane segment 30 is fixed to the portion on the inner side Dri of the casing 20 in the radial direction.

[0031] As in the Fig. 2 and Fig. 3, the vane segment 30 further includes a caulking member 90 that restricts the movement of the plurality of vanes 33 with respect to the vane ring 70, and two set screws 95a and 95b.

[0032] The guide vanes 33 constituting part of the guide vane segment 30 are formed, for example, from a Cr-based alloy or a Ni-based alloy. Each guide vane 33 includes a vane body 35, an inner shell 40, and an outer shell 50. The vane body 35 forms a blade shape and extends in the radial direction Dr. An edge on the upstream axial side Dau of the vane body 35 is a leading edge 36. An edge on the downstream axial side Dad of the vane body 35 is a trailing edge 37. The outer shell 40 is formed on the inner side Dri of the vane body 35 in the radial direction. The outer shell 50 is formed on the outer side Dro of the vane body 35 in the radial direction.

[0033] The inner shell 40 includes an upstream end surface 41u, a downstream end surface 41d, a pair of circumferential end surfaces 42, a gas path surface 43, an inner circumferential surface 44, and a ring engagement groove 45. The upstream end surface 41u faces the upstream axial side Dau. The downstream end surface 41d faces the downstream axial side Dad. This downstream end surface 41d is in a back-to-back relationship with the upstream end surface 41u. One circumferential end surface 42 of the pair of circumferential end surfaces 42 faces one side Dc1 in the circumferential direction Dc, and the other circumferential end surface 42 faces the other side Dc2 in the circumferential direction Dc.The gas path surface 43 faces the outer side Dro in the radial direction and connects the end on the outer side Dro in the radial direction of the upstream end surface 41u and the end on the outer side Dro in the radial direction of the downstream end surface 41d. The blade body 35 extends from the gas path surface 43 toward the outer side Dro in the radial direction. The inner peripheral surface 44 faces the inner side Dri in the radial direction and is in a back-to-back relationship with the gas path surface 43. The ring engagement groove 45 is recessed in the outer side Dro in the radial direction from the inner peripheral surface 44 and extends in the circumferential direction Dc.

[0034] The outer shell 50 includes an upstream end surface 51u, a downstream end surface 51d, a pair of circumferential end surfaces 52, an outer peripheral surface 53, a gas path surface 54, a contact inner peripheral surface 55, and an engagement groove 56. The upstream end surface 51u faces the upstream axial side (first side) Dau. The upstream end surface 51u includes an upstream outer end surface (first end surface) 51uo and an upstream inner end surface 51ui. The upstream outer end surface 51uo forms a portion of the outer side Dro in the radial direction of the upstream end surface 51u. The upstream inner end surface 51ui forms a portion of the inner side Dri in the radial direction of the upstream end surface 51u. The upstream inner end surface 51ui is located on the downstream axial side Dad from the upstream outer end surface 51uo.The downstream end surface (second end surface) 51d faces the downstream axial side (second side) Dad. This downstream end surface 51d is in a back-to-back relationship with the upstream end surface 51u. One circumferential end surface 52 of the pair of circumferential end surfaces 52 faces one side Dc1 in the circumferential direction Dc, and the other circumferential end surface 52 faces the other side Dc2 in the circumferential direction Dc. The outer peripheral surface 53 faces the outer side Dro in the radial direction and connects the end on the outer side Dro of the upstream end surface 51u in the radial direction and the end on the outer side Dro of the downstream end surface 51d in the radial direction. The gas path surface 54 faces the inner side Dri in the radial direction and connects the end on the inner side Dri of the upstream inner end surface 51ui and the end on the inner side Dri of the downstream end surface 51d in the radial direction.This gas path surface 54 is in a back-to-back relationship with the outer peripheral surface 53. The blade body 35 extends from the gas path surface 54 toward the inner side Dri in the radial direction. The contact inner peripheral surface 55 faces the inner side Dri in the radial direction, extends from the end of the inner side Dri of the upstream outer end surface (first end surface) 51uo in the radial direction to the downstream axial side (second side) Dad, to connect with the end of the outer side Dro of the upstream inner end surface 51ui in the radial direction. The engagement groove 56 is recessed from the downstream end surface 51d to the upstream axial side Dau and extends in the circumferential direction Dc. The engagement groove 56 is located on the outer side Dro of the contact inner peripheral surface 55 in the radial direction.

[0035] The gas path surface 54 of the outer shell 50 defines a portion of the edge of the outer side Dro of the vapor flow path 19 in the radial direction. The gas path surface 43 of the inner shell 40, which faces the gas path surface 54 of the outer shell 50 in the radial direction Dr, defines a portion of the edge of the inner side Dri of the vapor flow path 19 in the radial direction.

[0036] The seal ring 60, which forms part of the guide vane segment 30, includes an annular body 61, a convex engagement portion 62, and a plurality of seal ribs 63. The annular body 61 extends in the circumferential direction Dc. The convex engagement portion 62 protrudes from the outer side of the annular body 61 in the radial direction toward the outer side Dro in the radial direction and extends in the circumferential direction Dc. The convex engagement portion 62 fits into each of the annular engagement grooves 45 in the inner shells 40 of the plurality of guide vanes 33. The plurality of seal ribs 63 protrude from the inner side Dri of the annular body 61 in the radial direction toward the inner side Dri in the radial direction. Each seal rib 63 seals a gap between the guide vane 33 and the rotor shaft 11 in the radial direction Dr.

[0037] The blade ring 70, which forms part of the stationary vane segment 30, includes a pair of circumferential end surfaces 71, a gas path surface 72, a blade ring groove 73, and a bearing space forming portion 81. One circumferential end surface 71 of the pair of circumferential end surfaces 71 faces one side Dc1 in the circumferential direction Dc, and the other circumferential end surface 71 faces the other side Dc2 in the circumferential direction Dc. The gas path surface 72 faces the inner side Dri in the radial direction and extends in the circumferential direction Dc to connect one circumferential end surface 71 and the other circumferential end surface 71. The blade ring groove 73 is recessed from the gas path surface 72 toward the outer side Dro in the radial direction and extends in the circumferential direction Dc. The blade ring grooves 73 are open at each pair of circumferential end surfaces 71.Each of the outer shells 50 of the plurality of vanes 33 is inserted into the vane ring groove 73. The bearing space forming portion 81 cooperates with the outer shell 50 of the plurality of vanes 33 to form a bearing space 87 into which the caulking member 90 enters and in which the inner side Dri is open in the radial direction. The bearing space 87 is open to each of the pair of circumferential end surfaces 71. Note that hereinafter, the opening on the inner side Dri of the bearing space 87 in the radial direction is referred to as an inner opening 88i, and the opening of the circumferential end surface 71 of the bearing space 87 is referred to as a circumferential opening 88c.

[0038] The vane ring groove 73 includes an upstream groove side surface (first groove side surface) 74u, a downstream groove side surface (second groove side surface) 74d, a groove bottom surface 75, and a convex portion 76. The upstream groove side surface 74u faces the downstream axial side (second side) Dad and extends in the circumferential direction Dc. The upstream groove side surface 74u faces each of the upstream outer end surfaces (first end surfaces) 51uo of the outer shells 50 of the plurality of vanes 33. The downstream groove side surface 74d faces the upstream axial side (first side) Dau and extends in the circumferential direction Dc. The downstream groove side surface 74d faces each of the downstream end surfaces (second end surfaces) 51d of the outer shells 50 of the plurality of guide vanes 33.The groove bottom surface 75 faces the inner side Dri in the radial direction, extends in the circumferential direction Dc, and connects the upstream groove side surface (first groove side surface) 74u and the downstream groove side surface (second groove side surface) 74d. The groove bottom surface 75 faces each of the outer peripheral surfaces 53 of the outer shells 50 of the plurality of guide vanes 33. The convex portion 76 protrudes from the downstream groove side surface (second groove side surface) 74d toward the upstream axial side (first side) Dau and extends in the circumferential direction Dc. This convex portion 76 fits into each of the engagement grooves 56 in the outer shells 50 of the plurality of guide vanes 33.

[0039] The bearing space forming portion 81 includes a space bottom surface 82, a space back surface 83, a space base facing surface 84, and a space side surface 85. The space bottom surface 82 faces the inner side Dri in the radial direction, extends in the circumferential direction Dc, and extends from the end on the outer side Dro of the upstream groove side surface (first groove side surface) 74u in the radial direction to the upstream axial side (first side) Dau. The distance in the radial direction Dr from the groove bottom surface 75 to the chamber bottom surface 82 is substantially equal to the distance in the radial direction Dr from the outer peripheral surface 53 of the outer shell 50 to the contact inner peripheral surface 55. The chamber back surface 83 faces the downstream axial side Dad, extends in the circumferential direction Dc, and extends from one end on the upstream axial side Dau of the chamber bottom surface 82 to the inner side Dri in the radial direction.The chamber floor-facing surface 84 faces the outer side Dro in the radial direction, extends in the circumferential direction Dc, and extends from the end on the inner side Dri of the chamber rear surface 83 in the radial direction to the downstream axial side Dad. The chamber floor-facing surface 84 faces the chamber floor surface 82 in the radial direction Dr. The chamber side surface 85 faces the downstream axial side Dad, extends in the circumferential direction Dc, and extends from the end on the downstream axial side Dad of the opposite chamber floor surface 84 to the inner side Dri in the radial direction. The end on the inner side Dri of the chamber side surface 85 in the radial direction forms part of the edge of the inner opening 88i of the storage space 87.

[0040] The bearing space 87 into which the caulking member 90 enters is defined by each surface 82 to 85 of the bearing space forming portion 81, the contact inner peripheral surface 55 of the outer shell 50 entering the blade ring groove 73, and the upstream inner end surface 51ui of the outer shell 50. The cross-sectional shape of the bearing space 87 perpendicular to the circumferential direction and Dc forms an L-shape.

[0041] The caulking member 90, which forms part of the guide vane segment 30, is formed of a metal that is softer than the guide vanes 33, for example, stainless steel. The caulking member 90 includes a first piece portion 91 and a second piece portion 92. The first piece portion 91 extends in the axial direction Da and extends in the circumferential direction Dc. The second piece portion 92 extends from the downstream axial side end Dad of the first piece portion 91 to the inner side Dri in the radial direction and extends in the circumferential direction Dc. In other words, the cross-sectional shape of the caulking member 90 perpendicular to the circumferential direction Dc forms an L-shape to fit into the L-shaped bearing space 87.

[0042] As in the Fig. 2 to 4, of the plurality of guide vanes 33, a first outer shell 50a, which is the outer shell 50 of the guide vane 33 closest to the one side Dc1 in the circumferential direction Dc, and the blade ring 70 are formed with a first bolt hole 96a across the first outer shell 50a and the blade ring 70. As shown in Fig. 5, the first screw hole 96a is recessed from the circumferential direction end surface 71 on one side Dc1 of the pair of circumferential direction end surfaces 71 of the blade ring 70 and the circumferential direction end surface 52 on one side Dc1 of the pair of circumferential direction end surfaces 52 of the first outer shell 50a toward the other side Dc2 of the circumferential direction Dc. In this first screw hole 96a, internal threads are formed in the portion formed by the blade ring 70. On the other hand, in this first screw hole 96a, internal threads are not formed in the portion formed by the first outer shell 50a.

[0043] Among the plurality of blades 33, a second outer shell 50b, which is the outer shell 50 of the stationary blade 33 closest to the other side Dc2 in the circumferential direction Dc, and the blade ring 70 are formed with a second screw hole 96b across the second outer shell 50b and the blade ring 70. The second screw hole 96b is recessed from the circumferential end surface 71 on the other side Dc2 of the pair of circumferential end surfaces 71 of the blade ring 70 and the circumferential end surface 52 on the other side Dc2 of the pair of circumferential end surfaces 52 of the second outer shell 50b toward the one side Dc1 in the circumferential direction Dc. Internal threads are formed in this second screw hole 96b in the portion formed by the blade ring 70. On the other hand, in this second screw hole 96b, internal threads are not formed in the portion formed by the second outer shell 50b.

[0044] The first set screw (first limiting element) 95a of the two set screws 95a and 95b forming part of the guide vane segment 30 can be screwed into the first screw hole 96a. The second set screw (second limiting element) 95b of the two set screws 95a and 95b can be screwed into the second screw hole 96b. Note that the first screw hole 96a and the second screw hole 96b have the same shape and size. The first set screw 95a and the second set screw 95b have the same shape and size.

[0045] Next, a method for assembling the above-described vane segment 30 will be described.

[0046] In assembling the vane segment 30, the steps of attaching each of the inner shells 40 of the plurality of vanes 33 to the seal ring 60 and attaching each of the outer shells 50 of the plurality of vanes 33 to the blade ring 70 are performed.

[0047] In the step of attaching each of the outer shells 50 of the plurality of guide vanes 33 to the vane ring 70, first, as shown in Fig. 6 illustrates that the outer shells 50 of the plurality of vanes 33 are sequentially inserted into the vane ring grooves 73 of the vane ring 70. At this time, the outer shell 50 is inserted into the vane ring groove 73 from the opening of the circumferential end surface 71 of the vane ring groove 73. When the outer shell 50 enters the vane ring groove 73, the convex portion 76 of the vane ring groove 73 fits into the engagement groove 56 of the outer shell 50.

[0048] Next, the caulking member 90 is inserted into the bearing space 87, which is a gap between the bearing space forming portion 81 of the vane ring 70 and the outer shells 50 of the plurality of vanes 33. At this time, the caulking member 90 is moved in the circumferential direction Dc, and the caulking member 90 is inserted into the bearing space 87 from the circumferential opening 88c of the bearing space 87.

[0049] As in Fig. As illustrated in Fig. 7, at the time of receiving the caulking member 90 into the storage space 87, the end on the inner side Dri of the second piece portion 92 of the caulking member 90 is exposed in the radial direction from the inner opening 88i of the storage space 87. In the present embodiment, a portion of the caulking member 90 exposed from the inner opening 88i is impacted from the inner side Dri in the radial direction toward the outer side Dro in the radial direction using a tool such as a hammer. At this time, in the caulking member 90, most of the portions adjacent to the outer shells 50 of the plurality of vanes 33 aligned in the circumferential direction Dc are impacted by the tool.As a result, the caulking member 90 plastically deforms, and the first piece portion 91 of the caulking member 90 is in close contact with the inner contact circumferential surface 55 of the plurality of outer shells 50, the chamber bottom surface 82 of the blade ring 70, and the chamber bottom facing surface 84 of the blade ring 70. Furthermore, the second piece portion 92 of the caulking member 90 is in close contact with the upstream inner end surface 51ui of the plurality of outer shells 50 and the chamber side surface 85 of the blade ring 70. In other words, the plurality of outer shells 50 are caulked against the blade ring 70 by the caulking member 90. As a result, the outer shells 50 of the plurality of guide vanes 33 are restricted to be relatively immobile with respect to the blade ring 70 in the radial direction Dr and the axial direction Da.

[0050] Next, as in the Fig.4 to 6, the first set screw 95a is screwed into the first screw hole 96a and the second set screw 95b is screwed into the second screw hole 96b. When the first set screw 95a is screwed into the first screw hole 96a, among the plurality of outer shells 50 aligned in the circumferential direction Dc, the first outer shell 50a that is closest to one side in the circumferential direction Dc1 cannot move to the other side Dc1 in the circumferential direction Dc1 with respect to the blade ring 70. When the second set screw 95b is screwed into the second screw hole 96b, among the plurality of outer shells 50 aligned in the circumferential direction Dc, the second outer shell 50b that is closest to the other side Dc2 in the circumferential direction Dc cannot move to the other side Dc2 in the circumferential direction Dc with respect to the blade ring 70.As a result, the outer shells 50 of the plurality of guide vanes 33 disposed within the vane ring grooves 73 are constrained to be relatively immobile in the circumferential direction Dc with respect to the vane ring 70.

[0051] Here, after the plurality of outer shells 50 are caulked to the blade ring 70 by the caulking member 90, the two set screws 95a and 95b are screwed into the screw holes 96a and 96b, respectively. However, after the plurality of outer shells 50 are inserted into the blade ring groove 73, the plurality of outer shells 50 can be screwed into the screw holes 96a and 96b with two set screws 95a and 95b before being caulked to the blade ring 70 by the caulking member 90.

[0052] The assembly of the guide vane segment 30 is completed as described above.

[0053] In the present embodiment, in the downstream axial side portion Dad of the outer shell 50, the convex portion 76 of the blade ring groove 73 fits into the engagement groove 56 of the outer shell 50, and the relative movement of the outer shell 50 in the radial direction Dr with respect to the blade ring 70 is restricted. In the upstream axial side portion Dau of the outer shell 50, the caulking member 90 accommodated in the bearing space 87 contacts the surface of the outer shell 50 and the surface of the blade ring 70, which form the bearing space 87, and the relative movement of the outer shell 50 in the radial direction Dr with respect to the blade ring 70 is restricted.More specifically, in the upstream axial side portion Dau of the outer shell 50, the first piece portion 91 of the caulking member 90 is in close contact with the inner contact peripheral surface 55 of the plurality of outer shells 50, the space bottom surface 82 of the blade ring 70, and the opposite space base surface 84 of the blade ring 70, and the outer shell 50 cannot move relative to the blade ring 70 in the radial direction Dr. Furthermore, in the upstream axial side portion Dau of the outer shell 50, the second piece portion 92 of the caulking member 90 is in close contact with the upstream inner end surface 51ui of the plurality of outer shells 50 and the space side surface 85 of the blade ring 70, and the outer shell 50 cannot move relative to the axial direction Da with respect to the blade ring 70. Thus, in the present embodiment, the guide vanes 33 can be securely attached to the vane ring 70.

[0054] In the present embodiment, the cross-sectional shape of the storage space 87 is an L-shape, and the cross-sectional shape of the caulking member 90 that fits into the storage space 87 is also an L-shape, so that loosening of the caulking member 90 and slipping of the caulking member 90 from the storage space 87 can be prevented.

[0055] A force toward the downstream axial side Dad acts on the blade body 35 of the guide vane 33 through the steam S. In the present embodiment, the caulking member 90 is disposed on the upstream axial side Dau of the outer shell 50 of the guide vane 33. Thus, in the present embodiment, it is possible to minimize the deformation of the caulking member 90, which is formed of a softer material than the guide vane 33, due to the guide vanes 33 being subjected to a force on the downstream axial side.

[0056] The outer side portion Dro of the guide vane 33 in the radial direction is supported by the blade ring 70, and the inner side portion Dri in the radial direction is a free end. Therefore, when a force acts on the blade body 35 of the guide vane 33 on the downstream axial side Dad, a moment is exerted on the guide vane 33 by which the inner side portion Dro of the guide vane 33 in the radial direction is to rotate on the basis of the outer side portion Dri of the guide vane 33. In other words, a moment is exerted on the guide vane 33 by which the upstream axial side portion Dau of the outer shell 50 is to move toward the inner side Dri in the radial direction, and the downstream axial side portion Dad of the outer shell 50 is to move toward the outer side Dro in the radial direction.In the present embodiment, the caulking member 90, which restricts the movement of the upstream axial side portion Dau of the outer shell 50 in the radial direction Dr, is disposed on the inner side Dri in the radial direction of the convex portion 76 of the vane ring groove 73, which restricts the movement of the downstream axial side portion Dad of the outer shell 50 in the radial direction Dr. Thus, in the present embodiment, a moment acting on the stationary blade 33 can be effectively counteracted.

[0057] In the present embodiment, after the plurality of outer shells 50 are accommodated in the vane ring groove 73 and a caulking member 90 is accommodated in the storage space 87, the portion of the caulking member 90 adjacent to the outer shells 50 of the plurality of stationary blades 33 aligned in the circumferential direction Dc is hammered by a tool such as a hammer as described above. Thus, in the present embodiment, each time the outer shell 50 of a stationary blade 33 is inserted into the vane ring groove 73, for example, the process of inserting the caulking member and hammering the caulking member, and the process of compressing the leaf spring using a jig or the like, as in the technique described in JP 2007-107467 A, can be omitted. Thus, in the present invention, it is possible to reduce the man-hours for assembling the stationary blade segments 30.

[0058] In the present embodiment, the convex portion 76 of the vane ring groove 73 is disposed on the downstream axial side Dad of the outer shell 50, and the caulking member 90 is disposed on the upstream axial side Dau of the outer shell 50. However, the caulking member 90 may be disposed on the downstream axial side Dad of the outer shell 50, and the convex portion 76 of the vane ring groove 73 may be disposed on the upstream axial side Dau of the outer shell 50. In this case, however, the degree of deformation of the caulking member 90 is larger than that of the present embodiment due to the guide vanes 33 being subjected to a force toward the downstream axial side Dad.

[0059] In the present embodiment, the cross-sectional shape of the storage space 87 is an L-shape, and the cross-sectional shape of the caulking member 90 that fits into the storage space 87 is also an L-shape. However, the cross-sectional shape of the storage space 87 and the cross-sectional shape of the caulking member 90 are not limited to an L-shape. For example, the cross-sectional shape of the storage space and the cross-sectional shape of the caulking member may be more complex than an L-shape. The cross-sectional shape of the storage space may be a bar shape, and the cross-sectional shape of the caulking member may also be a bar shape. However, if the cross-sectional shape of the storage space and the cross-sectional shape of the caulking member are both bar shapes, loosening of the caulking member and slipping of the caulking member from the blade ring may possibly occur. Industrial applicability

[0060] According to one aspect of the present invention, it is possible to securely attach the guide vanes to the vane ring, thereby reducing assembly time. List of reference symbols 10 Rotor 11 Rotor shaft 12 rotor blade rows 13 rotor blades 19 Steam flow path 20 housings 21 Entrance 22 Outlet 25 Shaft sealing device 26 warehouses 30 guide vane segment 32 guide vane rows 33 guide vane 35 blade bodies 36 Front edge 37 Rear edge 40 inner cover 41u Upstream end face 41d Downstream end face 42 Circumferential end face 43 Gas path surface 44 inner circumferential surface 45 ring engagement groove 50 outer shell 50a First outer shell 50b Second outer shell 51u Upstream end face 51uo Upstream outer end face (first end face) 51ui Upstream inner end face 51d Downstream end face (second end face) 52 Circumferential end face 53 Outer peripheral surface 54 Gas path surface 55 Contact inner peripheral surface 56 engagement groove 60 sealing ring 61 ring bodies 62 Convex engagement section 63 Sealing rib 70 blade ring 71 Circumferential end face 72 Gas path surface 73 Blade ring groove 74u Upstream groove side surface (first groove side surface) 74d Downstream groove side surface (second groove side surface) 75 grooved bottom surface 76 Convex section 81 Storage room formation section 82 room floor area 83 Rear area of ​​the room 84 Surface facing the room floor 85 room side area 87 storage room 88c circumferential opening 88i Inner opening 90 caulking element 91 First section 92 Second section 95a First adjusting screw (first limiting element) 95b Second adjusting screw (second limiting element) 96a First screw hole 96b Second screw hole Ar axis BA guide vane assembly S Steam Since axial direction Dau Upstream axial side (first side) Dad Downstream axial side (second side) Dc circumferential direction Dc1 One side in circumferential direction Dc2 Other side in circumferential direction Dr radial direction Three inside in radial direction Dro outside in radial direction

Claims

[1] Guide vane segment (30) of a steam turbine, the guide vane segment (30) comprising: a blade ring (70) extending in the circumferential direction (Dc) with respect to an axis (Ar); a plurality of guide vanes (33) mounted on an inner side (Dri) in the radial direction with respect to the axis (Ar) of the blade ring (70) and aligned in the circumferential direction (Dc); and a caulking element (90) configured to limit the relative movement of the plurality of guide vanes (33) with respect to the vane ring (70), wherein each of the plurality of guide vanes (33) forms a blade shape and includes a blade body (35) extending in the radial direction (Dr) with respect to the axis (Ar) and an outer shell (50) formed on an outer side (Dro) in the radial direction (Dr) of the blade body (35) with respect to the axis (Ar), the outer shell (50) includes a first end surface (51uo), a second end surface (51d), an outer peripheral surface (53) and an engagement groove (56), the first end face (51uo) faces an upstream side (Dau) in the axial direction (Da) in which the axis (Ar) extends, the second end surface (51d) faces a downstream side (Dad) opposite the upstream side (Dau) in the axial direction (Da), the outer peripheral surface (53) faces the outer side (Dro) in the radial direction and connects one end on the outer side (Dro) of the first end surface (51uo) in the radial direction and one end on the outer side (Dro) of the second end surface (51d) in the radial direction, the engagement groove (56) is recessed from the second end surface (51d) to the upstream side (Dau) and extends in the circumferential direction (Dc), the blade ring (70) includes a gas path surface (43), a blade ring groove (73) and a bearing space forming section (81), the gas path surface (43) faces the inner side (Dri) in the radial direction and extends in the circumferential direction (Dc), the vane ring groove (73) is recessed from the gas path surface (43) towards the outer side (Dro) in the radial direction and extends in the circumferential direction (Dc) into which each of the outer shells (50) of the plurality of guide vanes (33) enters, the bearing space forming section (81) includes a surface forming a bearing space (87) which cooperates with the outer shells (50) of the plurality of guide vanes (33), into which the caulking element (90) enters and opens in the radial direction of the inner side (Dri), the blade ring groove (73) includes a first groove side surface (74u), a second groove side surface (74d), a groove bottom surface (75) and a convex portion (76), the first groove side surface (74u) faces the downstream side (Dad), extends in the circumferential direction (Dc) and faces each of the first end surfaces (51uo) of the outer shells (50) of the plurality of guide vanes (33), the second groove side surface (74d) faces the upstream side (Dau), extends in the circumferential direction (Dc) and faces each of the second end surfaces (51d) of the outer shells (50) of the plurality of guide vanes (33), the groove bottom surface (75) faces the inner side (Dri) in the radial direction, extends in the circumferential direction (Dc), connects the first groove side surface (74u) and the second groove side surface (74d), and faces each of the outer peripheral surfaces (53) of the outer shells (50) of the plurality of guide vanes (33), the convex portion (76) projects from the second groove side surface (74d) to the upstream side (Dau), extends in the circumferential direction (Dc) and fits into each of the engagement grooves (56) of the outer shells (50) in the plurality of guide vanes (33), the bearing space forming portion (81) is connected to one end on the inner side (Dri) of the first groove side surface (74u) in the radial direction, and the caulking member (90) extends in the circumferential direction (Dc), is housed in the bearing space (87), contacts the surface of the bearing space forming portion (81), contacts each of the outer shells (50) of the plurality of guide vanes (33), and is exposed from the opening (88i) of the bearing space (87). [2] Guide vane segment (30) of the steam turbine according to claim 1, wherein the outer shell (50) includes a contact inner peripheral surface (55) facing the inner side (Dri) in the radial direction and extending from one end on the inner side (Dri) of the first end surface (51uo) in the radial direction to the downstream side (Dad), the storage space forming section (81) includes a space floor surface (82) and a space side surface (85), the chamber bottom surface (82) faces the inner side (Dri) in the radial direction, extends in the circumferential direction (Dc) and extends from one end on the inner side (Dri) of the first groove side surface (74u) in the radial direction to the upstream side (Dau), the chamber side surface (85) is arranged on the inner side (Dri) in the radial direction of the chamber bottom surface (82), faces the downstream side (Dad) and extends in the radial direction (Dr) and circumferential direction (Dc), one end on the inside (Dri) of the space side surface (85) forms part of an edge on the opening (88i) of the storage space (87) in the radial direction, and the caulking member (90) contacts the chamber bottom surface (82) and the chamber side surface (85) and contacts each of the contact inner peripheral surfaces (55) of the outer shells (50) of the plurality of guide vanes (33). [3] Guide vane segment (30) of the steam turbine according to claim 2, wherein the storage space forming section (81) includes a rear surface (83) and a surface (84) facing the floor of the room, the chamber rear surface (83) faces the downstream side (Dad), extends in the circumferential direction (Dc) and extends from one end on the upstream side (Dau) of the chamber bottom surface to the inside (Dri) in the radial direction, the surface (84) facing the chamber floor faces the outer side (Dro) in the radial direction, extends in the circumferential direction (Dc), extends from one end on the inner side (Dri) of the chamber rear surface (83) in the radial direction to the downstream side (Dad) and faces the chamber floor surface (82) in the radial direction (Dr), the chamber side surface (85) extends from one end on the downstream side (Dad) of the surface (84) facing the chamber floor to the inside (Dri) in the radial direction, a cross-sectional shape of the storage space (87) in a plane perpendicular to the circumferential direction (Dc) forms an L-shape, and a cross-sectional shape of the caulking element (90) in the plane perpendicular to the circumferential direction (Dc) forms an L-shape which is fitted into the bearing space (87). [4] Guide vane segment (30) of the steam turbine according to one of claims 1 to 3, wherein one end of both ends of the blade body (35) in the axial direction (Da) forms a front edge (36) and another end forms a rear edge (37), wherein the front edge (36) is present on the upstream side (Dau) in the axial direction (Da) with respect to the rear edge (37), and wherein the rear edge (37) is present on the downstream side (Dad) in the axial direction (Da) with respect to the front edge (36). [5] Guide vane segment (30) of the steam turbine according to claim 2 or 3, wherein one end of both ends of the blade body (35) in the axial direction (Da) forms a front edge (36) and another end forms a rear edge (37), wherein the front edge (36) is present on the upstream side (Dau) in the axial direction (Da) with respect to the rear edge (37), wherein the rear edge (37) is present on the downstream side (Dad) in the axial direction (Da) with respect to the front edge (36), and the chamber floor surface (82) of the blade ring (70) is arranged on the inside in the radial direction (Dri) of the convex section (76) of the blade ring (70). [6] Guide vane segment (30) of the steam turbine according to one of claims 2, 3 and 5, wherein a distance in the radial direction (Dr) from the groove bottom surface (75) to the chamber bottom surface (82) of the blade ring (70) corresponds to the distance in the radial direction (Dr) from the outer peripheral surface (53) of the outer shell (50) to the contact inner peripheral surface (55) of the outer shell (50). [7] Guide vane segment (30) of the steam turbine according to one of claims 1 to 6, comprising: a first limiting element configured to limit the relative movement in the circumferential direction (Dc) with respect to the blade ring (70) of the outer shell (50) of a vane (33) located closest to a side in the circumferential direction (Dc) among the plurality of vanes (33) aligned in the circumferential direction (Dc); and a second limiting member configured to limit the relative movement in the circumferential direction (Dc) with respect to the blade ring (70) of the outer shell (50) of a guide vane (33) located closest to the other side in the circumferential direction (Dc) among the plurality of guide vanes (33) aligned in the circumferential direction (Dc). [8] Steam turbine, comprising: the guide vane segment (30) of the steam turbine according to one of claims 1 to 7; a rotor (10) configured to rotate about the axis (Ar); and a housing (20) configured to cover the vane segments (30) and the rotor (10).

Images