Rotor disc, rotor shaft, turbine rotor, and gas turbine

Abstract

This rotor disc comprises a disc body and a plurality of seal ring pieces. The disc body has a large-diameter part and a small-diameter part. The large-diameter part has a plurality of blade grooves which are recessed radially inward and to which blade roots of rotor blades can be attached. The small-diameter part has an annular groove recessed toward the axial downstream side and extending in the circumferential direction, and a plurality of holes through which cooling air can flow in. The plurality of holes penetrate from the small-diameter inner circumferential surface to the inner groove-side surface of the annular groove in a plurality of blade groove in-between areas, which are regions in between the plurality of blade grooves in the circumferential direction. The seal ring pieces each have: a ring piece body that covers the opening of the annular groove and secures an annular groove inner passage between the ring piece body and the annular groove bottom surface; and a protrusion that protrudes from the ring piece body toward the axial downstream side in the blade groove in-between areas. The protrusions of the seal ring pieces have a protrusion connecting passage for connecting the holes and the annular groove inner passage.

Description

Rotor disk, rotor shaft, turbine rotor, and gas turbine

[0001] This application claims priority to Japanese Patent Application No. 2024-052252, filed on March 27, 2024, the contents of which are incorporated herein by reference.

[0002] A gas turbine has a compressor that compresses air to generate compressed air, a combustor that burns fuel in the compressed air to generate combustion gas, and a turbine driven by the combustion gas. The turbine has a turbine rotor that rotates about an axis and a turbine casing that covers the turbine rotor. The turbine rotor has a rotor shaft that rotates about the axis and extends in the axial direction, and a plurality of rows of rotor blades. The plurality of rows of rotor blades are aligned in the axial direction. Each of the plurality of rows of rotor blades has a plurality of rotor blades aligned in the circumferential direction about the axis. The rotor shaft is configured, for example, by stacking a plurality of rotor disks in the axial direction.

[0003] The following Patent Document 1 discloses the configuration of a rotor disk, which includes a disk body and a plurality of seal ring pieces attached to the disk body.

[0004] The disk body has a cylindrical large diameter portion centered on the axis and an annular small diameter portion centered on the axis. The large diameter portion is recessed radially inward from its outer circumferential surface and has multiple blade grooves into which blade roots of rotor blades can be fitted. The small diameter portion is recessed downstream from its front end face along the axis and has an annular groove extending circumferentially relative to the axis and multiple holes extending radially. The annular groove is in communication with the multiple blade grooves. Each of the multiple holes penetrates from the inner circumferential surface of the small diameter portion to an inner groove side surface that faces radially outward within the surface defining the annular groove. Of the multiple holes, each of the multiple first holes is formed in an inter-blade groove region, which is a region between the multiple blade grooves in the circumferential direction. Of the multiple holes, each of the multiple second holes is formed in a blade groove region, which is a region where multiple blade grooves exist in the circumferential direction.

[0005] The seal ring segment has a ring segment body that forms an annular groove passage between itself and a bottom surface of the annular groove that faces the axial upstream side among the surfaces that define the annular groove, and a protrusion that protrudes from the ring segment body to the axial downstream side in the region between the blade grooves. This protrusion comes into contact with the bottom surface of the annular groove and divides the annular groove passage in the circumferential direction.

[0006] Cooling air for cooling the blade can flow into the multiple holes. Of the multiple holes, the cooling air that flows into the multiple second holes flows into the blade groove through annular groove passages formed by the annular groove. The cooling air that flows into the blade groove flows into the blade from the root of the blade that is fitted into the blade groove. On the other hand, of the multiple holes, the cooling air that flows into the first hole cannot flow into the annular groove passage that communicates with the blade groove due to the convex portion of the seal ring piece. In other words, cooling air is not supplied to the blade from the first hole.

[0007] Tensile stress is generated in the rotor disk when the rotor disk rotates around its axis. The tensile stress generated in the rotor disk is concentrated near the openings of the holes. Therefore, in the technology described in Patent Document 1 below, in addition to second holes that can supply cooling air to the rotor blades, first holes that cannot supply cooling air to the rotor blades are provided in order to alleviate the concentration of stress near the openings of the second holes.

[0008] Japanese Patent Application Laid-Open No. 2020-193564

[0009] In recent years, the temperature of the combustion gas sent from the combustor to the turbine has been increased to improve gas turbine efficiency. As the temperature of the combustion gas increases, it is necessary to increase the amount of cooling air for cooling the rotor blades exposed to the combustion gas.

[0010] In the technology described in Patent Document 1, the amount of cooling air flowing into the rotor blades can be increased by increasing the diameter of the second holes. However, this method requires machining the disk body, which increases the machining cost.

[0011] Therefore, an object of the present disclosure is to provide a technique that can adjust the amount of cooling air flowing into the rotor blade while suppressing processing costs.

[0012] To achieve the above object, one aspect of the invention provides a rotor disk comprising: a disk body; and a plurality of seal ring segments attached to the disk body. The disk body has a cylindrical large-diameter portion centered on an axis; and a small-diameter portion that protrudes from the large-diameter portion toward either the upstream or downstream side in the axial direction along which the axis extends, is annular about the axis, and has an outer diameter smaller than that of the large-diameter portion. The large-diameter portion has a large-diameter outer peripheral surface facing radially outward relative to the axis, and a plurality of blade grooves recessed from the large-diameter outer peripheral surface radially inward relative to the axis, into which blade roots of blades can be fitted. The small diameter portion has a small diameter outer peripheral surface facing radially outward, a small diameter inner peripheral surface facing radially inward, a small diameter end surface facing the one side and having a radially outer edge connected to the one edge of the small diameter outer peripheral surface, an annular groove recessed from the small diameter end surface toward the other side opposite the one side and extending in a circumferential direction about the axis, small diameter communicating passages provided for each of the plurality of blade grooves for communicating a space within the annular groove with a space within the blade groove, and a plurality of holes extending in a radial direction about the axis to allow cooling air to flow in. Each of the plurality of holes penetrates from the small diameter inner peripheral surface to the inner groove side surface facing radially outward in any one of a plurality of inter-blade groove regions that are regions between the plurality of blade grooves in the circumferential direction about the axis. The plurality of seal ring pieces are aligned in the circumferential direction and fit into the annular groove. Each of the plurality of seal ring pieces has a ring piece main body that closes the opening of the annular groove and is spaced apart in the axial direction from a bottom surface of the annular groove that faces the upstream side of the axis among the surfaces that define the annular groove, to ensure an annular groove passage between the ring piece main body and the bottom surface, and a protrusion that protrudes from the ring piece main body to the other side in the inter-blade groove region and enters the annular groove passage. The protrusion of the seal ring piece has a protrusion communicating passage that connects the hole and the annular groove passage.

[0013] In this aspect, the cooling air that flows into the hole flows into the annular groove passage through the convex portion communication passage in the convex portion of the seal ring segment. The cooling air that flows into the annular groove passage flows into the blade groove through the small diameter communication passage. The cooling air that flows into the blade groove flows into the cooling air passage of the blade fitted in the blade groove, cooling the blade.

[0014] As described above, in the main body aspect, cooling air can be sent to the rotor blades by processing the seal ring segments, which are much smaller than the disk main body, without processing the disk main body. Moreover, in this aspect, the flow rate of cooling air sent to the rotor blades can be adjusted by appropriately adjusting the cross-sectional area of ​​the convex portion communicating passages formed in the seal ring segments.

[0015] Therefore, in this aspect, the amount of cooling air flowing into the rotor blade can be adjusted while suppressing the processing cost.

[0016] A rotor shaft according to one aspect of the invention for achieving the above object comprises a plurality of rotor disks according to the above aspect, and a spindle bolt that passes through the plurality of rotor disks arranged in the axial direction in the axial direction and connects the plurality of rotor disks to each other.

[0017] In order to achieve the above object, a turbine rotor according to one aspect of the invention includes the rotor shaft according to the above aspect, and blades attached to the blade grooves of each of the plurality of rotor disks.

[0018] In order to achieve the above object, a gas turbine according to one aspect of the invention includes the turbine rotor according to the above aspect, and a turbine casing that covers an outer periphery of the turbine rotor.

[0019] According to one aspect of the present invention, it is possible to adjust the amount of cooling air flowing into the rotor blade while suppressing processing costs.

[0020] FIG. 1 is a schematic diagram showing the configuration of a gas turbine according to an embodiment of the present invention. FIG. 1 is a cross-sectional view of a main portion of a turbine according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of a main portion of a rotor disk according to an embodiment of the present invention. FIG. 3 is a view of a disk body and rotor blades according to an embodiment of the present invention, viewed from the upstream side of the axial line. FIG. 4 is a cross-sectional view of the disk body along line V-V in FIG. 4. FIG. 4 is a cross-sectional view of the disk body along line VI-VI in FIG. 4. FIG. 4 is a view of the disk body as viewed from the VII arrow in FIG. 4. FIG. 5 is a view of a seal ring segment according to an embodiment of the present invention, viewed from the radially outer side. FIG. 8 is a cross-sectional view of the seal ring segment according to an embodiment of the present invention. FIG. 9 is a cross-sectional view of a seal ring segment according to a modified embodiment of the present invention.

[0021] Hereinafter, embodiments of a gas turbine including a rotor disk according to the present invention, and various embodiments of the rotor disk will be described with reference to the drawings.

[0022] Embodiment of Gas Turbine An embodiment of a gas turbine according to the present invention will be described with reference to the drawings.

[0023] As shown in FIG. 1 , the gas turbine 10 of this embodiment includes a compressor 20 capable of compressing air A, a combustor 30 capable of burning fuel F in the air A compressed by the compressor 20 to generate combustion gas G, and a turbine 40 capable of being driven by the combustion gas G.

[0024] The compressor 20 has a compressor rotor 21 that rotates about the axis Ar, a compressor casing 25 that covers the compressor rotor 21, and a plurality of stator vane rows 26. 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 vane rows 46. Note that, hereinafter, the direction in which the axis Ar extends is referred to as the axial direction Da, the circumferential direction centered on 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.

[0025] The gas turbine 10 of this embodiment further includes an intermediate casing 16. The compressor 20 is disposed on the axial upstream side Dau with respect to the turbine 40. The intermediate casing 16 is disposed between the compressor casing 25 and the turbine casing 45 in the axial direction Da, and connects the compressor casing 25 and the turbine casing 45. 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. For example, a rotor of a generator GEN is connected to this gas turbine rotor 11. 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.

[0026] The compressor rotor 21 has a rotor shaft 22 extending in the axial direction Da centered on 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 is composed of a plurality of rotor blades aligned in the circumferential direction Dc. One of a plurality of stator blade rows 26 is arranged on the axial downstream side Dad of each of the plurality of rotor blade rows 23. Each stator blade row 26 is provided inside the compressor casing 25. Each stator blade row 26 is composed of a plurality of stator blades aligned in the circumferential direction Dc.

[0027] 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 is composed of a plurality of rotor blades 44 aligned in the circumferential direction Dc. One of the plurality of stator blade rows 46 is arranged on the axial upstream side Dau of each of the plurality of rotor blade rows 43. Each stator blade row 46 is provided radially inward of the turbine casing 45. Each stator blade row 46 is composed of a plurality of stator blades 47 aligned in the circumferential direction Dc.

[0028] 2, the turbine casing 45 includes a cylindrical outer casing 45a constituting its outer shell, an inner casing 45b fixed to the radially inner side of the outer casing 45a, a plurality of heat shield rings 45c fixed to the radially inner side of the inner casing 45b, and ring segments 45d fixed to the radially inner side of each of the heat shield rings 45c. Each of the ring segments 45d is provided between the plurality of stator blade rows 46. Therefore, the rotor blade rows 43 are disposed on the radially inner side Dri of each ring segment 45d. Furthermore, a stator blade 47 is also fixed to the radially inner side Dri of each of the plurality of heat shield rings 45c.

[0029] The annular space between the outer periphery of the rotor shaft 42 and the inner periphery of the turbine casing 45, in which the stator blades 47 and rotor blades 44 are arranged in the axial direction Da, forms a combustion gas flow path 49 through which the combustion gas G from the combustor 30 flows.

[0030] As shown in FIG. 1 , the gas turbine 10 of this embodiment is provided with a cooling device 50. This cooling device 50 cools high-temperature components of the gas turbine that come into contact with high-temperature combustion gas. The cooling device 50 includes an extraction line 51 that extracts compressed air from the intermediate casing 16, a cooler 52 provided in the extraction line 51, a cooling air line 53 that guides the compressed air cooled by the cooler 52 as cooling air to the turbine rotor 41, which is one of the high-temperature components, and a booster 54 provided in the cooling air line 53 that boosts the pressure of the cooling air. A cooling air flow path 42p is formed in the rotor shaft 42 of the turbine 40. The cooling air flow path 42p extends to a plurality of rotor blades 44 attached to the rotor shaft 42.

[0031] As shown in FIG. 2 , the rotor shaft 42 has a plurality of rotor disks 42d arranged in the axial direction Da and spindle bolts 42s that penetrate the plurality of rotor disks 42d in the axial direction Da and connect the plurality of rotor disks 42d to one another. A plurality of rotor blades 44 constituting one rotor blade row 43 are attached to one rotor disk 42d. Each rotor blade 44 has an airfoil-shaped blade body 44b, a platform 44f formed on the radially inner side Dri of the blade body 44b, and a blade root 44r formed on the radially inner side Dri of the platform 44f. A cooling air passage 44p through which cooling air flows is formed in the rotor blade 44. An inlet opening of the cooling air passage 44p is formed in the bottom surface of the blade root 44r facing the radially inner side Dri.

[0032] As shown in FIG. 1 , the compressor 20 compresses air A to generate compressed air. This compressed air flows from the compressor 20 into the intermediate casing 16. A portion of the compressed air that has flowed into the intermediate casing 16 flows into the combustor 30. Fuel F is supplied to the combustor 30. In the combustor 30, the fuel F is combusted in the compressed air, generating high-temperature, high-pressure combustion gas G. This combustion gas G is sent from the combustor 30 to a combustion gas flow path 49 in the turbine 40. As the combustion gas G flows through the combustion gas flow path 49 toward the axial downstream side Dad, it rotates the turbine rotor 41. This rotation of the turbine rotor 41 rotates the rotor of a generator GEN connected to the gas turbine rotor 11. As a result, the generator GEN generates electricity.

[0033] The rotor blades 44 and stator vanes 47 of the turbine 40 are exposed to high-temperature combustion gas G. For this reason, the rotor blades 44 and stator vanes 47 are cooled with a cooling medium. In this embodiment, the rotor blades 44 are cooled with cooling air from a cooling device 50. A portion of the compressed air generated by the compressor 20 is extracted from the intermediate casing 16. This compressed air flows through an extraction line 51 into a cooler 52, where it is cooled. The compressed air cooled in the cooler 52 is pressurized by a booster 54, and then flows through a cooling air line 53 into a cooling air flow path 42p of the rotor shaft 42 as cooling air Ac. This cooling air Ac flows from the cooling air flow path 42p of the rotor shaft 42 into the cooling air passage 44p of the rotor blades 44, where it cools the rotor blades 44.

[0034] The rotor disk 42d described above will be described in detail below.

[0035] [Embodiment of Rotor Disk] Hereinafter, a rotor disk according to this embodiment will be described with reference to FIGS.

[0036] As shown in FIGS. 2 and 3, the rotor disk 60 in this embodiment includes a disk body 61, a plurality of seal ring pieces 90, and a plurality of seal caps 85.

[0037] The disk body 61 has a large diameter portion 62, a small diameter portion 72, and multiple protruding portions 81, 83. The large diameter portion 62 is cylindrical and centered on the axis Ar. The small diameter portion 72 is annular and centered on the axis Ar. The outer diameter of the small diameter portion 72 is smaller than the outer diameter of the large diameter portion 62. The small diameter portion 72 is provided on the axial upstream side Dau of the large diameter portion 62. The protruding portions 81, 83 include an upstream protruding portion 81 that protrudes from the axial upstream side Dau surface of the small diameter portion 72 toward the axial upstream side Dau, and a downstream protruding portion 83 that protrudes from the axial downstream side Dad surface of the large diameter portion 62 toward the axial downstream side Dad.

[0038] As shown in Figures 2 to 4, the large diameter portion 62 has a large diameter outer peripheral surface 63 facing the radially outer side Dro, and a plurality of blade grooves 64 recessed from the large diameter outer peripheral surface 63 toward the radially inner side Dri. The plurality of blade grooves 64 are arranged at equal intervals in the circumferential direction Dc. Each blade groove 64 has a blade groove bottom surface 64b (see Figure 4) facing the radially outer side Dro. A blade root 44r of the rotor blade 44 is attached to each of the plurality of blade grooves 64.

[0039] As shown in Figures 3 to 6, the annular small diameter portion 72 has a small diameter outer peripheral surface 73o facing the radially outward direction Dro, a small diameter inner peripheral surface 73i facing the radially inward direction Dri, a small diameter end face 74 facing the axial upstream side Dau, a plurality of small diameter communicating grooves 75, an annular groove 76, and a plurality of holes 77.

[0040] As shown in Figures 3, 4, and 6, each of the multiple small-diameter communicating grooves 75 is recessed radially inward Dri from the small-diameter outer peripheral surface 73o to a position radially inward Dri of the blade groove bottom surface 64b. Each of the multiple small-diameter communicating grooves 75 is formed in one of the blade groove regions AG, which are regions in which multiple blade grooves 64 exist in the circumferential direction Dc. The small-diameter communicating groove 75 has a communicating groove bottom surface 75b facing radially outward Dro. This communicating groove bottom surface 75b is located radially inward Dri of the blade groove bottom surface 64b. Therefore, each of the multiple small-diameter communicating grooves 75 is in communication with one of the multiple blade grooves 64.

[0041] As shown in FIGS. 3 to 5 , the annular groove 76 is recessed from the small-diameter end surface 74 of the small-diameter portion 72 toward the axial downstream side Dad and extends in the circumferential direction Dc. The annular groove 76 has an inner groove side surface 76i facing the radially outer side Dro, an outer groove side surface 76o facing the radially inner side Dri, and an annular groove bottom surface 76b facing the axially upstream side Dau. The inner groove side surface 76i is located radially inward Dri of the outer groove side surface 76o and faces the outer groove side surface 76o in the radial direction Dr. As shown in FIG. 6 , a portion of the inner groove side surface 76i of the annular groove 76 forms the communicating groove bottom surface 75b of the small-diameter communicating groove 75. Therefore, the annular groove 76 is in communication with multiple small-diameter communicating grooves 75.

[0042] As shown in FIGS. 3 to 7 , the multiple holes 77 include multiple first holes 77 a and multiple second holes 77 b. The multiple first holes 77 a and the multiple second holes 77 b all extend in the radial direction Dr and penetrate from the small-diameter inner circumferential surface 73 i of the small-diameter portion 72 to the inner groove side surface 76 i of the annular groove 76. Each of the multiple second holes 77 b opens in one of the blade groove regions AG, in the inner groove side surface 76 i of the annular groove 76, where multiple blade grooves 64 exist in the circumferential direction Dc. Each of the multiple first holes 77 a opens in one of the inter-blade groove regions AM, which are regions between the multiple blade grooves 64 in the circumferential direction Dc, in the inner groove side surface 76 i of the annular groove 76. The blade groove regions AG and the inter-blade groove regions AM are alternately arranged in the circumferential direction Dc. Therefore, the first holes 77 a and the second holes 77 b are arranged alternately in the circumferential direction Dc. Cooling air Ac can flow into both the first holes 77 a and the second holes 77 b from the radially inner side Dri of the annular small diameter portion 72.

[0043] As shown in Figures 3, 8, and 9, the seal ring segment 90 has a ring segment main body 91 and a protrusion 92. The ring segment main body 91 closes the opening of the annular groove 76 and is spaced apart from the annular groove bottom surface 76b in the axial direction Da to define an annular groove passage 76p between the ring segment main body 91 and the annular groove bottom surface 76b. The protrusion 92 has a first protrusion 92A and a second protrusion 92B. Both the first protrusion 92A and the second protrusion 92B protrude from the ring segment main body 91 toward the axial downstream side Dad and divide the annular groove passage 76p in the circumferential direction Dc. The first protrusion 92A protrudes from the ring segment main body 91 toward the axial downstream side Dad at a position where the first hole 77a is located in a first inter-blade groove region AM1 among the multiple inter-blade groove regions AM. The second convex portion 92B protrudes from the ring piece main body 91 toward the axial downstream side Dad at a position where the first hole 77a is present in a second inter-blade groove region AM2 among the multiple inter-blade groove regions AM. The first inter-blade groove region AM1 and the second inter-blade groove region AM2 are adjacent to each other in the circumferential direction Dc, sandwiching the blade groove region AG. A first annular groove passage 76pa is formed by the ring piece main body 91 between the first convex portion 92A and the second convex portion 92B in the circumferential direction Dc. A second annular groove passage 76pb is formed by the ring piece main body 91 in the region opposite the first convex portion 92A in the circumferential direction Dc, relative to the second convex portion 92B.

[0044] The first convex portion 92A has a ring piece bolt hole 93, a first convex portion inner surface 92Ai, and a first convex portion communicating groove 92Ag. The ring piece bolt hole 93 penetrates the first convex portion 92A in the radial direction Dr and communicates with the first hole 77a located in the first inter-blade groove region AM1. The first convex portion inner surface 92Ai faces the radially inward direction Dr and faces the inner groove side surface 76i of the annular groove 76. The first convex portion communicating groove 92Ag is recessed radially outward from the first convex portion inner surface 92Ai and extends from the ring piece bolt hole 93 in the circumferential direction Dc to communicate with the first annular groove passage 76pa. The first convex portion communicating passage 92Ap is formed by a portion of the space formed by the ring piece bolt hole 93 and the space within the first convex portion communicating groove 92Ag. The first convex portion communication passage 92Ap connects the first hole 77a present in the first inter-blade groove region AM1 with the first annular groove passage 76pa.

[0045] The second protrusion 92B has a second protrusion inner surface 92Bi and a second protrusion communicating groove 92Bg. The second protrusion inner surface 92Bi faces the radially inward direction Dri and faces the inner groove side surface 76i of the annular groove 76. The second protrusion communicating groove 92Bg is recessed from the second protrusion inner surface 92Bi toward the radially outward direction Dro and extends in the circumferential direction Dc, connecting the first hole 77a present in the second inter-blade groove region AM2 to the second annular groove passage 76pb. A second protrusion communicating passage 92Bp, which connects the first hole 77a present in the second inter-blade groove region AM2 to the second annular groove passage 76pb, is formed in the space within the second protrusion communicating groove 92Bg.

[0046] The cross-sectional area of ​​the first hole 77a is the same at any position in the radial direction Dr. The cross-sectional area of ​​the second hole 77b is the same at any position in the radial direction Dr. The cross-sectional area of ​​the first hole 77a is the same as the cross-sectional area of ​​the second hole 77b. The cross-sectional area of ​​the first protrusion communicating groove 92Ag is the same at any position in the circumferential direction Dc. The cross-sectional area of ​​the second protrusion communicating groove 92Bg is the same at any position in the circumferential direction Dc. The cross-sectional area of ​​the second protrusion communicating groove 92Bg is the same as the cross-sectional area of ​​the first protrusion communicating groove 92Ag and is smaller than the cross-sectional areas of the second hole 77b and the first hole 77a. Therefore, in this embodiment, the minimum cross-sectional areas of the first protrusion communicating passages 92Ap and the second protrusion communicating passages 92Bp are smaller than the minimum cross-sectional areas of the second hole 77b and the first hole 77a.

[0047] 3, 7, and 8, the small diameter portion 72 has small diameter bolt holes 79 in the first inter-blade groove region AM1 that penetrate from the small diameter outer peripheral surface 73o into the blade grooves 64. The small diameter bolt holes 79 communicate with ring piece bolt holes 93 in the first convex portion 92A. Bolts 99 for attaching the seal ring pieces 90 to the small diameter portion 72 are inserted into the small diameter bolt holes 79 and ring piece bolt holes 93.

[0048] 10 , the seal cap 85 enters the small-diameter communicating groove 75 from the radially outer side Dro and closes the opening of the small-diameter communicating groove 75. A gap is formed in the radial direction Dr between the seal cap 85 and the communicating groove bottom surface 75b of the small-diameter communicating groove 75. This gap forms a small-diameter communicating passage 75p that communicates between the annular groove passage 76p and the space within the blade groove 64.

[0049] 4, 8, and 10, the cooling air Ac that flows into the second holes 77b present in the blade groove region AG in the circumferential direction Dc flows through these second holes 77b radially outward Dro and flows into the blade groove 64 via the small diameter communicating passage 75p. The cooling air Ac that flows into the blade groove 64 flows into the cooling air passage 44p from the inlet opening of the cooling air passage 44p of the rotor blade 44 that is fitted in this blade groove 64. The cooling air Ac that flows into the cooling air passage 44p cools the rotor blade 44, and then flows out of this rotor blade 44 into the combustion gas flow path 49. Therefore, the second holes 77b form main air holes for the rotor blade 44.

[0050] As shown in Figures 4, 8, and 9, cooling air Ac that flows into the first holes 77a present in the first inter-blade-groove region AM1 in the circumferential direction Dc flows radially outward through the first holes 77a and into the first convexity communicating passages 92Ap formed in the first convexity 92A of the seal ring segment 90. The cooling air Ac that flows into the first convexity communicating passages 92Ap flows in the circumferential direction Dc through the first convexity communicating passages 92Ap and flows into the blade grooves 64 via the first annular groove passages 76pa formed between the annular groove 76 and the ring segment main body 91 and the small-diameter communicating passages 75p connected to the first annular groove passages 76pa. The cooling air Ac that flows into the blade grooves 64 flows into the cooling air passages 44p through the inlet openings of the cooling air passages 44p of the blades 44 fitted in the blade grooves 64. Therefore, the first holes 77a serve as auxiliary air holes for the blades 44.

[0051] That is, the cooling air Ac from the first holes 77a present in the first inter-blade-groove region AM1 also flows into the moving blade 44 into which the cooling air Ac from the second holes 77b present in the blade groove region AG flows.

[0052] The cooling air Ac that flows into the first holes 77a present in the second inter-blade groove region AM2 in the circumferential direction Dc flows radially outward within the first holes 77a and into a second convex portion communicating passage 92Bp formed in the second convex portion 92B of the seal ring segment 90. The cooling air Ac that flows into the second convex portion communicating passage 92Bp flows in the circumferential direction Dc within the second convex portion communicating passage 92Bp and flows into the blade groove 64 via a second annular groove passage 76pb formed between the annular groove 76 and the ring segment main body 91 and a small diameter communicating passage 75p connected to the second annular groove passage 76pb. The cooling air Ac that flows into the blade groove 64 flows into the cooling air passage 44p from the inlet opening of the cooling air passage 44p of the blade root 44r fitted in the blade groove 64. The blade 44 into which this cooling air Ac flows is the blade 44 adjacent in the circumferential direction Dc to the blade 44 into which the cooling air Ac flows from the first hole 77a present in the first blade groove inter-region AM1, and is the blade 44 that is present on the opposite side of the first convex portion 92A in the circumferential direction Dc based on the second convex portion 92B.

[0053] Cooling air Ac also flows into this moving blade 44 from the second holes 77 b in the blade groove region AG where the blade groove 64 into which this moving blade 44 is fitted exists, via the small diameter communicating passage 75 p and the blade groove 64 .

[0054] That is, the blade 44 into which cooling air Ac flows from the first hole 77a present in the second blade groove inter-region AM2 also receives cooling air Ac from the second hole 77b in the blade groove region AG in which the blade groove 64 into which the blade 44 is fitted is present.

[0055] As described above, in this embodiment, the first hole 77a, the second hole 77b, the first convex portion connecting passage 92Ap, the second convex portion connecting passage 92Bp, the annular groove passage 76p, the small diameter connecting passage 75p, and the space within the blade groove 64 form part of the cooling air flow path 42p described using Figures 1 and 2.

[0056] Incidentally, the first holes 77a, which are auxiliary air holes in this embodiment, are holes whose main purpose is to alleviate stress concentration near the openings of the second holes 77b, which are main air holes. In this embodiment, the disk body 61 is not machined, but rather the seal ring piece 90, which is a component much smaller than the disk body 61, is machined, thereby making it possible to send the cooling air Ac that has flowed into the auxiliary air holes (first holes) 77a to the rotor blades 44. Furthermore, in this aspect, the flow rate of the cooling air Ac sent to the rotor blades 44 can be adjusted by appropriately adjusting the cross-sectional areas of the convex portion communicating passages 92Ap, 92Bp formed in this seal ring piece 90.

[0057] Therefore, in this embodiment, the amount of cooling air Ac flowing into the rotor blades 44 can be adjusted while suppressing processing costs.

[0058] Modified Example of Rotor Disk A modified example of the rotor disk in the above embodiment will be described with reference to FIG.

[0059] In the above embodiment, the first convex portion 92A of the seal ring piece 90 has the ring piece bolt hole 93 and the first convex portion communicating groove 92Ag, and the second convex portion 92B of this seal ring piece 90 has the second convex portion communicating groove 92Bg. However, as shown in Fig. 11 , the first convex portion 92A of the seal ring piece 90 may have the first convex portion communicating groove 92Ag, and the second convex portion 92B of this seal ring piece 90 may have the ring piece bolt hole 93 and the second convex portion communicating groove 92Bg. In this modification, the space formed within the first convex portion communicating groove 92Ag forms the first convex portion communicating passage 92Ap, and a part of the space formed by the ring piece bolt hole 93 and the space formed within the second convex portion communicating groove 92Bg form the second convex portion communicating passage 92Bp. In addition, in this modified example, a small diameter bolt hole 79 communicating with the aforementioned ring piece bolt hole 93 is formed in the second blade groove inter-region AM2, which is the region in the small diameter portion 72 where the second convex portion 92B exists in the circumferential direction Dc.

[0060] In the above-described embodiment and modifications, the cross-sectional shapes of the second hole 77 b and the first hole 77 a are both round. However, the cross-sectional shapes of the second hole 77 b and the first hole 77 a do not have to be round, and only one of the cross-sectional shapes does not have to be round.

[0061] In the above embodiment and modified examples, one second hole 77b is provided for one blade groove region AG. However, a plurality of second holes 77b may be provided for one blade groove region AG.

[0062] In the above-described embodiment and modified examples, the convex portion 92 of the seal ring piece 90 has convex portion communicating grooves 92Ag, 92Bg formed along the convex portion inner surfaces 92Ai, 92Bi, and the spaces including the spaces within the convex portion communicating grooves 92Ag, 92Bg are defined as the convex portion communicating passages 92Ap, 92Bp. However, the convex portion 92 of the seal ring piece 90 may have a hole extending in the circumferential direction Dc at a central position in the radial direction Dr of the convex portion 92, and the space within the hole may be a part of the convex portion communicating passages 92Ap, 92Bp. However, if the convex portion 92 does not have ring piece bolt holes 93, it is preferable to form the convex portion communicating groove 92Bg in the convex portion 92 and define the space within the convex portion communicating groove 92Bg as the convex portion communicating passage 92Bp, as in the above-described embodiment and modified examples. This is because, if the convex portion 92 does not have a ring piece bolt hole 93, in order to form the convex portion communicating passage 92Bp in the convex portion 92, in addition to a hole extending in the circumferential direction Dc at the middle position in the radial direction Dr of the convex portion 92, it is also necessary to form a hole extending in the radial direction Dr that communicates with the first hole 77a.

[0063] In the above-described embodiment and modified examples, the seal ring segment 90 has two protrusions 92. However, the number of protrusions 92 may be one or three or more. When the number of protrusions 92 is one, a seal ring segment 90 having a first protrusion 92A and a seal ring segment 90 having a second protrusion 92B are arranged in the circumferential direction Dc. When the number of protrusions 92 is three, a seal ring segment having a first protrusion 92A, a second protrusion 92B, and a first protrusion 92A arranged in the circumferential direction Dc, and a seal ring segment having a second protrusion 92B, a first protrusion 92A, and a second protrusion 92B arranged in the circumferential direction Dc are arranged in the circumferential direction Dc.

[0064] However, if the seal ring piece has only one convex portion, the number of seal ring pieces that block the opening of the annular groove 76 increases, resulting in increased labor required to install the seal ring pieces. Furthermore, two types of seal ring pieces 90 must be prepared: a seal ring piece with a first convex portion and a reel ring piece with a second convex portion. Also, as mentioned above, if the seal ring piece has three convex portions, two types of seal ring pieces must be prepared. Furthermore, if the seal ring piece has three or more convex portions, the length of each seal ring piece in the circumferential direction Dc increases, making handling more difficult. For these reasons, as in the above-described embodiments and modifications, it is preferable for the seal ring piece to have two convex portions.

[0065] In the above embodiment and modified examples, there are two types of protrusions 92: protrusion 92A having ring piece bolt holes 93, and protrusion 92B not having ring piece bolt holes 93. However, all of the protrusions may have ring piece bolt holes 93. Also, all of the protrusions may not have ring piece bolt holes 93. However, it is preferable that at least one of the multiple seal ring segments has one protrusion having a ring piece bolt hole. This is to determine the circumferential positions of the multiple seal ring segments within the annular groove 76 of the small diameter portion 72.

[0066] In the above-described embodiment and modified examples, the small diameter portion 72 protrudes from the large diameter portion 62 toward the axial upstream side Dau. However, the small diameter portion 72 may protrude from the large diameter portion 62 toward the axial downstream side Dad. In this case, the small diameter end face 74 faces the axial downstream side Dad. The annular groove 76 is recessed from the small diameter end face 74 toward the axial upstream side Dau. Furthermore, the protrusions 92, 92A, 92B of the seal ring piece 90 protrude from the ring piece main body 91 of the seal ring piece 90 toward the axial upstream side Dau.

[0067] In the above embodiment and modified examples, the protrusions 92, 92A, 92B of the seal ring piece 90 divide the annular groove passage 76p in the circumferential direction Dc. However, the protrusions 92, 92A, 92B do not have to divide the annular groove passage 76p in the circumferential direction Dc.

[0068] 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.

[0069] [Additional Notes] The rotor disk 60 in the above-described embodiment and each of the modified examples can be understood, for example, as follows.

[0070] (1) A rotor disk 60 according to a first aspect includes a disk body 61 and a plurality of seal ring pieces 90 attached to the disk body 61. The disk body 61 has a cylindrical large-diameter portion 62 centered on the axis Ar, and a small-diameter portion 72 that protrudes from the large-diameter portion 62 toward either an axial upstream side Dau or an axial downstream side Dad in the axial direction Da along which the axis Ar extends, is annular and centered on the axis Ar, and has an outer diameter smaller than that of the large-diameter portion 62. The large-diameter portion 62 has a large-diameter outer peripheral surface 63 that faces a radially outer side Dro relative to the axis Ar, and a plurality of blade grooves 64 that are recessed from the large-diameter outer peripheral surface 63 toward a radially inner side Dri relative to the axis Ar, and into which blade roots 44r of blades 44 can be fitted. The small diameter portion 72 has a small diameter outer peripheral surface 73o facing the radially outer side Dro, a small diameter inner peripheral surface 73i facing the radially inner side Dri, a small diameter end face 74 facing the one side Dau and having an edge of the radially outer side Dro connected to an edge of the one side Dau of the small diameter outer peripheral surface 73o, an annular groove 76 recessed from the small diameter end face 74 to the other side Dad opposite the one side Dau and extending in a circumferential direction Dc relative to the axis Ar, small diameter communicating passages 75p provided for each of the plurality of blade grooves 64 and connecting the space within the annular groove 76 with the space within the blade groove 64, and a plurality of holes 77a extending in the radial direction Dr relative to the axis Ar and through which cooling air Ac can flow. Each of the plurality of holes 77a penetrates from the small diameter inner circumferential surface 73i to an inner groove side surface 76i that faces the radially outer side Dro among the surfaces that define the annular groove 76, in any one of a plurality of inter-blade groove regions AM that are regions between the plurality of blade grooves 64 in the circumferential direction Dc relative to the axis Ar. The plurality of seal ring pieces 90 are lined up in the circumferential direction Dc and each fits into the annular groove 76. Each of the multiple seal ring pieces 90 has a ring piece main body 91 that closes the opening of the annular groove 76 and is spaced apart in the axial direction Da from an annular groove bottom surface 76b that faces the axial upstream side Dau among the surfaces that define the annular groove 76, thereby ensuring an annular groove passage 76p between itself and the annular groove bottom surface 76b, and convex portions 92, 92A, 92B that protrude from the ring piece main body 91 to the other side Dad in the inter-blade groove region AM and enter the annular groove passage 76p.The protrusions 92, 92A, 92B of the seal ring piece 90 have protrusion communication passages 92Ap, 92Bp that communicate between the hole 77a and the annular groove passage 76p.

[0071] In this embodiment, the cooling air Ac that has flowed into the hole 77a flows into the annular groove passage 76p via the convex portion communication passages 92Ap, 92Bp of the convex portions 92, 92A, 92B of the seal ring piece 90. The cooling air Ac that has flowed into the annular groove passage 76p flows into the blade groove 64 via the small diameter communication passage 75p. The cooling air Ac that has flowed into the blade groove 64 flows into the cooling air passage 44p of the blade 44 fitted in the blade groove 64, and cools the blade 44.

[0072] As described above, in the main body aspect, the cooling air Ac can be sent to the rotor blades 44 by processing the seal ring piece 90, which is a component that is much smaller than the disk main body 61, without processing the disk main body 61. Furthermore, in this aspect, the flow rate of the cooling air Ac sent to the rotor blades 44 can be adjusted by appropriately adjusting the cross-sectional areas of the convex portion communicating passages 92Ap, 92Bp formed in the seal ring piece 90.

[0073] Therefore, in this embodiment, the amount of cooling air Ac flowing into the rotor blade 44 can be adjusted while suppressing the processing cost.

[0074] (2) A rotor disk 60 according to a second aspect is the rotor disk 60 according to the first aspect, wherein the convex portions 92, 92A, 92B of the seal ring piece 90 have convex portion inner surfaces 92Ai, 92Bi and convex portion communicating grooves 92Ag, 92Bg. The convex portion inner surfaces 92Ai, 92Bi face the radially inner side Dri and face the inner groove side surface 76i of the annular groove 76. The convex portion communicating grooves 92Ag, 92Bg are recessed from the convex portion inner surfaces 92Ai, 92Bi toward the radially outer side Dro, extend in the circumferential direction Dc, and communicate with the annular groove passage 76p. The convex portion communicating passages 92Ap, 92Bp are formed by having spaces within the convex portion communicating grooves 92Ag, 92Bg.

[0075] A hole extending in the circumferential direction Dc may be formed in the protrusion 92 of the seal ring piece 90 at a central position in the radial direction Dr of the protrusion 92, with the space within this hole serving as a part of the protrusion communicating passage. In this case, however, to form the protrusion communicating passage in the protrusion 92, in addition to the hole extending in the circumferential direction Dc at the central position in the radial direction Dr of the protrusion 92, a hole extending in the radial direction Dr that communicates with the hole 77a in the small diameter portion 72 must also be formed. On the other hand, in this embodiment, the protrusion communicating passages 92Ap, 92Bp can be formed in the space within the protrusion communicating grooves 92Ag, 92Bg that are recessed radially outward from the protrusion inner surfaces 92Ai, 92Bi and extend in the circumferential direction Dc. In this manner, in this embodiment, there is no need to form an additional hole extending in the radial direction Dr that communicates with the hole 77a in the small diameter portion 72, thereby reducing processing costs.

[0076] (3) A rotor disk 60 according to a third aspect includes the rotor disk 60 according to the first aspect, and includes bolts 99 for fixing each of the seal ring segments 90 to the disk body 61. The small diameter portion 72 has small diameter bolt holes 79 in the inter-blade groove region AM, which penetrate from the small diameter outer peripheral surface 73o into the annular groove 76 and allow the bolts to be inserted therethrough. The convex portion 92A of the seal ring segment 90 has ring piece bolt holes 93, a convex portion inner side surface 92Ai, and a convex portion communicating groove 92Ag. The ring piece bolt holes 93 penetrate the convex portion 92A in the radial direction Dr, communicate with the small diameter bolt holes 79, and allow the bolts 99 to be inserted therethrough. The convex portion inner side surface 92Ai faces the radially inward direction Dr and faces the inner groove side surface 76i of the annular groove 76. The convex portion communicating groove 92Ag is recessed from the convex portion inner surface 92Ai toward the radially outer side Dro, extends from the ring piece bolt hole 93 in the circumferential direction Dc, and communicates with the annular groove passage 76p. The convex portion communicating passage 92Ap is formed by a part of the space formed by the ring piece bolt hole 93 and the space within the convex portion communicating groove 92Ag.

[0077] In this embodiment, a part of the space formed by the ring piece bolt holes 93 penetrating the protrusion 92A in the radial direction Dr is used as part of the protrusion communication passage 92Ap, so that the processing cost can be reduced.

[0078] (4) A rotor disk 60 according to a fourth aspect is the rotor disk 60 according to the first aspect, wherein the convex portions 92A, 92B in the rotor disk 60 according to the first aspect include a first convex portion 92A protruding from the ring piece main body 91 in a first inter-blade groove region AM1 among the plurality of inter-blade groove regions AM, and a second convex portion 92B protruding from the ring piece main body 91 in a second inter-blade groove region AM2 among the plurality of inter-blade groove regions AM that is adjacent to the first inter-blade groove region AM1 in the circumferential direction Dc. The first convex portion 92A of the seal ring piece 90 includes a first convex portion communicating passage 92Ap that is the convex portion communicating passage 92Ap that connects the hole 77a present in the first inter-blade groove region AM1 among the plurality of holes 77a, with a first annular groove passage 76pa that is the annular groove passage 76p formed in the annular groove 76 between the first convex portion 92A and the second convex portion 92B. The second convex portion 92B of the seal ring piece 90 has a second convex portion communicating passage 92Bp which is a convex portion communicating passage 92Bp that connects the hole 77a among the multiple holes 77a that exists in the second blade groove inter-region AM2 with the second annular groove intra-passage 76p which is the annular groove intra-passage 76p formed on the opposite side of the first convex portion 92A in the circumferential direction Dc with respect to the second convex portion 92B in the annular groove 76.

[0079] If the seal ring piece 90 has only one protrusion 92, the number of seal ring pieces 90 that block the opening of the annular groove 76 increases, and the labor required to install the seal ring pieces 90 increases. Also, if the seal ring piece 90 has three or more protrusions 92, the length of each seal ring piece 90 in the circumferential direction Dc increases, making handling more difficult. For these reasons, it is preferable that the seal ring piece 90 have two protrusions 92, as in this embodiment.

[0080] (5) A rotor disk 60 according to a fifth aspect includes the rotor disk 60 according to the fourth aspect, and includes bolts 99 for fixing each of the seal ring segments 90 to the disk body 61. The small diameter portion 72 has small diameter bolt holes 79, which penetrate from the small diameter outer peripheral surface 73o into the annular groove 76 in the first inter-blade groove region AM1 and through which the bolts can be inserted. The first convex portion 92A has ring piece bolt holes 93, a first convex portion inner side surface 92Ai, and a first convex portion communicating groove 92Ag. The ring piece bolt holes 93 penetrate the first convex portion 92A in the radial direction Dr and communicate with the small diameter bolt holes 79, through which the bolts 99 can be inserted. The first convex portion inner side surface 92Ai faces the radially inward direction Dr and faces the inner groove side surface 76i of the annular groove 76. The first convex portion communicating groove 92Ag is recessed from the first convex portion inner surface 92Ai toward the radially outer side Dro and extends from the ring piece bolt hole 93 in the circumferential direction Dc to communicate with the first annular groove passage 76pa. The first convex portion communicating passage 92Ap is formed by a part of the space formed by the ring piece bolt hole 93 and the space within the first convex portion communicating groove 92Ag. The second convex portion 92B has a second convex portion inner surface 92Bi and a second convex portion communicating groove 92Bg. The second convex portion inner surface 92Bi faces the radially inner side Dri and faces the inner groove side surface 76i of the annular groove 76. The second convex portion communicating groove 92Bg is recessed from the second convex portion inner surface 92Bi toward the radially outer side Dro and extends in the circumferential direction Dc to communicate with the second annular groove passage 76pb. The second convex portion communication passage 92Bp is formed by the space within the second convex portion communication groove 92Bg.

[0081] In this embodiment, the first convex portion 92A, which is one of the two convex portions 92A, 92B that the seal ring piece 90 has, has a ring piece bolt hole 93, so that by inserting a bolt 99 into this ring piece bolt hole 93, the seal ring piece 90 can be easily positioned and fixed to the small diameter portion 72.

[0082] (6) A rotor disk 60 according to a sixth aspect includes the rotor disk 60 according to the fourth aspect, and further includes bolts 99 for fixing each of the seal ring segments 90 to the disk body 61. The small diameter portion 72 has small diameter bolt holes 79, which penetrate from the small diameter outer peripheral surface 73o into the annular groove 76 in the second inter-blade groove region AM2 and through which the bolts 99 can be inserted. The first convex portion 92A has a first convex portion inner surface 92Ai and a first convex portion communicating groove 92Ag. The first convex portion inner surface 92Ai faces the radially inner side Dri and faces the inner groove side surface 76i of the annular groove 76. The first convex portion communicating groove 92Ag is recessed from the first convex portion inner surface 92Ai toward the radially outer side Dro, extends in the circumferential direction Dc, and communicates with the first annular groove passage 76pa. The first protrusion communicating passage 92Ap is formed in the space within the first protrusion communicating groove 92Ag. The second protrusion 92B has a ring piece bolt hole 93, a second protrusion inner side surface 92Bi, and a second protrusion communicating groove 92Bg. The ring piece bolt hole 93 penetrates the second protrusion 92B in the radial direction Dr and communicates with the small diameter bolt hole 79, allowing the bolt 99 to be inserted therethrough. The second protrusion inner side surface 92Bi faces the radially inner side Dri and faces the inner groove side surface 76i of the annular groove 76. The second protrusion communicating groove 92Bg is recessed from the second protrusion inner side surface 92Bi toward the radially outer side Dro, extends from the ring piece bolt hole 93 in the circumferential direction Dc, and communicates with the second annular groove passage 76pb. The second convex portion communication passage 92Bp is formed by a part of the space formed by the ring piece bolt hole 93 and the space inside the second convex portion communication groove 92Bg.

[0083] In this embodiment, the second convex portion 92B, which is one of the two convex portions 92A, 92B that the seal ring piece 90 has, has a ring piece bolt hole 93, so that by inserting a bolt into this ring piece bolt hole 93, the seal ring piece 90 can be easily positioned and fixed to the small diameter portion 72.

[0084] (7) A rotor disk 60 according to a seventh aspect is the rotor disk 60 according to any one of the first to sixth aspects, wherein the minimum cross-sectional area of ​​the protrusion communicating passages 92Ap, 92Bp is smaller than the minimum cross-sectional area of ​​the hole 77a.

[0085] (8) In an eighth aspect, the rotor disk 60 is the rotor disk 60 of any one of the first to seventh aspects, wherein the small diameter portion 72 has a plurality of second holes 77b in addition to the first holes 77a that are the holes 77a present in each of the plurality of inter-blade groove regions AM. Each of the plurality of second holes 77b extends in the radial direction Dr in one of the blade groove regions AG after a plurality of blade groove regions AG that are regions in which the plurality of blade grooves 64 exist in the circumferential direction Dc, and penetrates from the small diameter inner circumferential surface 73i to the inner groove side surface 76i of the annular groove 76.

[0086] In this embodiment, more cooling air Ac can be guided to the rotor blade 44 than when the holes 77a include only the first holes 77a. Furthermore, since the small diameter portion 72 has a plurality of first holes 77a and a plurality of second holes 77b, stress concentration near the openings of the holes 77a, 77b can be alleviated.

[0087] The rotor shaft 42 in the above-described embodiments and modified examples can be understood, for example, as follows: (9) The rotor shaft 42 in a ninth aspect includes a plurality of rotor disks 60 in any one of the first to eighth aspects, and also includes spindle bolts 42s that penetrate, in the axial direction Da, the plurality of rotor disks 60 that are arranged in the axial direction Da and connect the plurality of rotor disks 60 to each other.

[0088] The turbine rotor 41 in the above-described embodiment and each modified example can be understood, for example, as follows: (10) A turbine rotor 41 in a tenth aspect includes the rotor shaft 42 in the ninth aspect and rotor blades 44 attached to the blade grooves 64 of each of the plurality of rotor disks 60.

[0089] The gas turbine 10 in the above-described embodiment and each modified example can be understood, for example, as follows: (11) A gas turbine 10 in an eleventh aspect includes the turbine rotor 41 in the tenth aspect and a turbine casing 45 that covers the outer periphery of the turbine rotor 41.

[0090] According to one aspect of the present disclosure, it is possible to adjust the amount of cooling air flowing into the rotor blade while suppressing processing costs.

[0091] 10: Gas turbine 11: Gas turbine rotor 15: Gas turbine casing 16: Intermediate casing 20: Compressor 21: Compressor rotor 22: Rotor shaft 23: Rotor blade row 25: Compressor casing 26: Stator blade row 30: Combustor 40: Turbine 41: Turbine rotor 42: Rotor shaft 42p: Cooling air flow path 42d, 60: Rotor disk 42s: Spindle bolt 43: Rotor blade row 44: Rotor blade 44b: Blade body 44f: Platform 44r: Blade root 42p: Cooling air flow path 45: Turbine casing 45a: Outer casing 45b: Inner casing 45c: Heat shield ring 45d: Segment ring 46: Stator blade row 47: Stator blade 49: Combustion gas flow path 50: Cooling device 51: Extraction line 52: Cooler 53: Cooling air line 54: Booster 61: Disk body 62: Large diameter portion 63: Large diameter outer peripheral surface 64: Blade groove 64b: Blade groove bottom surface 72: Small diameter portion 73o: Small diameter outer peripheral surface 73i: Small diameter inner peripheral surface 74: Small diameter end face 75: Small diameter connecting groove 75b: Connecting groove bottom surface 75p: Small diameter connecting passage 76: Annular groove 76i: Inner groove side surface 76o: Outer groove side surface 76b: Annular groove bottom surface 76p: Annular groove passage 76pa: First annular groove passage 76pb: Second annular groove passage 77: Hole 77a: First hole (or auxiliary air hole) 77b: Second hole (or main air hole) 79: Small diameter bolt hole 81: Upstream side protrusion 83: Downstream side protrusion 85: Seal cap 90: Seal ring piece 91: Ring piece main body 92: Convex portion 92A: First convex portion 92Ai: Inner surface of first convex portion 92Ag: First convex portion communicating groove 92Ap: First convex portion communicating passage 92B: Second convex portion 92Bi: Inner surface of second convex portion 92Bg: Second convex portion communicating groove 92Bp: Second convex portion communicating passage 93: Ring piece bolt hole 99: Bolt A: Air Ac: Cooling air F: Fuel G: Combustion gas AG: Blade groove region AM: Inter-blade groove region AM1: First inter-blade groove region AM2: Second inter-blade groove region Ar: Axis Da: Axial direction Dau: Axial upstream side Dad: Axial downstream side Dc: Circumferential direction Dr: Radial direction Dri: Radially inner side Dro: Radially outer side

Claims

1. A disk body comprising: a disk body; and a plurality of seal ring pieces attached to the disk body, wherein the disk body has: a large diameter portion that is cylindrical about an axis; and a small diameter portion that protrudes from the large diameter portion to either the upstream side or the downstream side in the axial direction along which the axis extends, is annular about the axis, and has an outer diameter smaller than the outer diameter of the large diameter portion, wherein the large diameter portion has: a large diameter outer peripheral surface facing radially outward relative to the axis; and a plurality of blade grooves that are recessed from the large diameter outer peripheral surface radially inward relative to the axis and into which blade roots of blades can be fitted, wherein the small diameter portion has: a small diameter outer peripheral surface facing radially outward; a small diameter inner peripheral surface facing radially inward; and a small diameter end surface that faces the one side and whose radially outer edge is connected to the edge on the one side of the small diameter outer peripheral surface; an annular groove recessed from the small diameter end face to the other side opposite to the one side and extending in a circumferential direction about the axis; small diameter communicating passages provided for each of the plurality of blade grooves for communicating a space within the annular groove with a space within the blade groove; and a plurality of holes extending in a radial direction about the axis to allow cooling air to flow in, wherein each of the plurality of holes penetrates from the small diameter inner peripheral surface to an inner groove side surface facing radially outward in a surface defining the annular groove, in any one of a plurality of inter-blade groove regions which are regions between the plurality of blade grooves in the circumferential direction about the axis; the plurality of seal ring pieces are lined up in the circumferential direction and each fit into the annular groove, and each of the plurality of seal ring pieces: a ring piece body that closes an opening of the annular groove and is spaced in the axial direction from an annular groove bottom surface facing the axial upstream side in the surface defining the annular groove to ensure an annular groove passage between itself and the annular groove bottom surface; a convex portion that protrudes from the ring piece main body to the other side in the inter-blade groove region and enters the annular groove passage, and the convex portion of the seal ring piece has a convex portion communicating passage that communicates the hole with the annular groove passage.

2. A rotor disk as claimed in claim 1, wherein the convex portion of the seal ring segment has a convex portion inner surface and a convex portion communicating groove, the convex portion inner surface faces radially inward and faces the inner groove side surface of the annular groove, the convex portion communicating groove is recessed radially outward from the convex portion inner surface and extends in the circumferential direction to communicate with the annular groove inner passage, and the convex portion communicating passage is formed by having a space within the convex portion communicating groove.

3. A rotor disk as claimed in claim 1, comprising bolts for fixing each of the plurality of seal ring pieces to the disk body, wherein the small diameter portion has small diameter bolt holes in the inter-blade groove region that penetrate from the small diameter outer circumferential surface into the annular groove and through which the bolts can be inserted, the convex portion of the seal ring piece has ring piece bolt holes, a convex portion inner surface and a convex portion communicating groove, wherein the ring piece bolt holes penetrate the convex portion in the radial direction and communicate with the small diameter bolt holes so that the bolts can be inserted, the convex portion inner surface faces radially inward and faces the inner groove side surface of the annular groove, the convex portion communicating groove is recessed radially outward from the convex portion inner surface and extends circumferentially from the ring piece bolt holes to communicate with the annular groove intra-passage, and the convex portion communicating passage is formed by a part of the space formed by the ring piece bolt holes and the space within the convex portion communicating groove.

4. A rotor disk as claimed in claim 1, wherein the convex portion comprises a first convex portion protruding from the ring piece main body in a first inter-blade groove region among the plurality of inter-blade groove regions, and a second convex portion protruding from the ring piece main body in a second inter-blade groove region among the plurality of inter-blade groove regions that is adjacent to the first inter-blade groove region in the circumferential direction, the first convex portion of the seal ring piece having a first convex portion communicating passage that is the convex portion communicating passage that connects a hole among the plurality of holes that exists in the first inter-blade groove region with a first annular groove passage that is the annular groove passage formed in the annular groove between the first convex portion and the second convex portion, and the second convex portion of the seal ring piece having a second convex portion communicating passage that is the convex portion communicating passage that connects a hole among the plurality of holes that exists in the second inter-blade groove region with a second annular groove passage that is the annular groove passage formed in the annular groove on the opposite side of the second convex portion to the first convex portion in the circumferential direction with respect to the second convex portion.

5. A rotor disk according to claim 4, further comprising bolts for fixing each of the plurality of seal ring segments to the disk body, the small diameter portion having small diameter bolt holes in the first inter-groove region that penetrate from the small diameter outer circumferential surface into the annular groove and through which the bolts can be inserted, the first convex portion having ring piece bolt holes, a first convex portion inner surface, and a first convex portion communicating groove, the ring piece bolt holes penetrating the first convex portion in the radial direction and communicating with the small diameter bolt holes so that the bolts can be inserted, the first convex portion inner surface facing inward in the radial direction and opposing the inner groove side surface of the annular groove, the first convex portion communicating groove recessed radially outward from the first convex portion inner surface and extending circumferentially from the ring piece bolt holes to communicate with the first annular groove passage, the first convex portion communicating passage being formed by a part of the space formed by the ring piece bolt holes and the space within the first convex portion communicating groove, the second convex portion has a second convex portion inner surface and a second convex portion communicating groove, the second convex portion inner surface faces radially inward and faces the inner groove side surface of the annular groove, the second convex portion communicating groove is recessed radially outward from the second convex portion inner surface and extends in the circumferential direction to communicate with the second annular groove passage, and the second convex portion communicating passage is formed by a space within the second convex portion communicating groove.

6. A rotor disk according to claim 4, comprising bolts for fixing each of the plurality of seal ring segments to the disk body, the small diameter portion having small diameter bolt holes in the second inter-blade groove region that penetrate from the small diameter outer circumferential surface into the annular groove and through which the bolts can be inserted, the first convex portion having a first convex portion inner surface and a first convex portion communicating groove, the first convex portion inner surface facing inward in the radial direction and opposing the inner groove side surface of the annular groove, the first convex portion communicating groove recessed radially outward from the first convex portion inner surface and extending in the circumferential direction to communicate with the first annular groove passage, the first convex portion communicating groove being formed in the space within the first convex portion communicating groove, and the second convex portion having ring piece bolt holes, a second convex portion inner surface and a second convex portion communicating groove, the ring piece bolt holes penetrate the second convex portion in the radial direction and communicate with the small diameter bolt holes, allowing the bolts to be inserted therethrough; the inner surface of the second convex portion faces radially inward and faces the inner groove side surface of the annular groove; the second convex portion communicating groove is recessed radially outward from the inner surface of the second convex portion and extends circumferentially from the ring piece bolt holes to communicate with the second annular groove inner passage; and the second convex portion communicating passage is formed by a part of the space formed by the ring piece bolt holes and the space within the second convex portion communicating groove.

7. A rotor disk according to claim 1, wherein the minimum cross-sectional area of ​​the protrusion communicating passage is smaller than the minimum cross-sectional area of ​​the hole.

8. A rotor disk as claimed in claim 1, wherein the small diameter portion has a plurality of second holes in addition to the first holes which are the holes present in each of the plurality of inter-blade groove regions, and each of the plurality of second holes extends in the radial direction in any one of a plurality of blade groove regions which are regions in which a plurality of blade grooves exist in the circumferential direction, penetrating from the small diameter inner peripheral surface to the inner groove side surface of the annular groove.

9. A rotor shaft comprising a plurality of rotor disks according to any one of claims 1 to 8, and a spindle bolt passing through the plurality of rotor disks arranged in the axial direction in the axial direction and connecting the plurality of rotor disks to each other.

10. A turbine rotor comprising: a rotor shaft according to claim 9; and rotor blades mounted in the blade grooves of each of the plurality of rotor disks.

11. A gas turbine comprising: a turbine rotor according to claim 10; and a turbine casing that covers the outer periphery of the turbine rotor.

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