Turbine rotor, and gas turbine equipped therewith

Abstract

To elongate axial length of a portion receiving force from a rotor disc, of a rotor blade and furthermore to suppress axial length of the rotor blade as a whole.SOLUTION: A turbine rotor comprises a rotor disc, a rotor blade, and a lid member amounted to the rotor disc. The rotor blade has a blade body, a platform arranged at an end of the blade body at the radial inside, a shank arranged at the radial inside of the platform, and a blade root arranged at the radial inside the of a shank. The rotor disc has a columnar small-diameter portion and a columnar large-diameter portion having an outside diameter larger than that of the small-diameter portion. The small-diameter portion has a passage groove recessed toward radial inside from an outer periphery of the small-diameter portion. The large-diameter portion has a blade groove recessed toward the radial inside from the radial outside in such a way as to allow the insertion of the blade root. The lid member blocks an opening of the passage groove.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a turbine rotor and a gas turbine including the same.

Background Art

[0002] A gas turbine includes a compressor that compresses air to generate compressed air, a combustor that burns fuel in the compressed air to generate fuel gas, and a turbine that is driven by the combustion gas. The turbine includes a turbine rotor that rotates about an axis, a turbine casing that covers the rotor, and a plurality of stationary blade rows.

[0003] For example, Patent Document 1 below discloses a turbine rotor of a gas turbine. This turbine rotor has a plurality of disk units arranged in the axial direction in which the axis extends, and a spindle bolt that extends in the axial direction and couples the plurality of disk units to each other. One disk unit has one rotor disk and one moving blade row attached to the outer peripheral portion of this rotor disk. One moving blade row has a plurality of moving blades arranged in the circumferential direction with respect to the axis.

[0004] The moving blade has a blade body, a platform, a shank, and a blade root. The blade body has an airfoil shape in a cross section perpendicular to the radial direction with respect to the axis and extends in the radial direction. The platform is provided at the end on the inner side in the radial direction of the blade body. The shank is provided on the inner side in the radial direction of the platform and extends in an inclined direction. The inclined direction is a direction that forms an included angle with respect to the axis. The blade root is provided on the inner side in the radial direction of the shank and extends in the inclined direction. The cross-sectional shape perpendicular to the inclined direction of the blade root is a shape that repeats concavities and convexities in the circumferential direction, in other words, a Christmas tree shape. The plurality of stationary blade rows are arranged in the axial direction and attached to the inner peripheral side of the turbine casing. Each of the plurality of stationary blade rows is arranged upstream of the axis of any one of the moving blade rows for each of the plurality of disk units. Each stationary blade row has a plurality of stationary blades arranged in the circumferential direction with respect to the axis.

[0005] The rotor disk of the final stage disk unit, which is the disk unit furthest downstream of the axis among the multiple disk units, has a cylindrical rear shaft portion centered on the axis, a first small-diameter portion that is cylindrical centered on the axis and has an outer diameter larger than the outer diameter of the rear shaft portion, a second small-diameter portion that is cylindrical centered on the axis and has an outer diameter larger than the outer diameter of the first small-diameter portion, and a large-diameter portion that is cylindrical centered on the axis and has an outer diameter larger than the outer diameter of the second small-diameter portion. The first small-diameter portion is connected to the upstream side of the axis of the rear shaft portion. The second small-diameter portion is connected to the upstream side of the axis of this first small-diameter portion. The large-diameter portion is connected to the upstream side of the axis of this second small-diameter portion.

[0006] The rear shaft section has a main cooling air passage through which cooling air can flow. The main cooling air passage extends from the rear end face of the rear shaft section toward the upstream side of the axis into the second small-diameter section.

[0007] The first small-diameter section has a plurality of first radial passages and a plurality of axial passages. The first radial passages extend radially within the first small-diameter section. The radially inner ends of these first radial passages are connected to the axially upstream end of the main cooling air passage. The axial passages extend from the radially outer ends of the second radial passages toward the axially upstream side into the first small-diameter section.

[0008] The second small-diameter section has a second radial passage and a passage groove. The second radial passage extends radially within the second small-diameter section. The radially inner end of this second radial passage is connected to the axial upstream end of the axial passage. The passage groove is recessed radially inward from the outer circumferential surface of the second small-diameter section, with its radially outer edge forming an opening, and extends in an inclined direction toward the axial upstream side from the radially outer end of the second radial passage.

[0009] The large-diameter section has a groove for each of the multiple rotor blades. The grooves are recessed radially inward from the outer surface of the large-diameter section and extend in the direction of inclination. The grooves have a Christmas tree-like cross-sectional shape perpendicular to the direction of inclination, similar to the rotor blade roots, so that the blade roots can fit into them. The bottom surface of these grooves is connected to the bottom surface of the passage groove.

[0010] The rotor blade comprises the aforementioned body, platform, shank, and root, as well as a jaw and a blade cooling air passage. The jaw protrudes in an inclined direction from the root toward the downstream axis. This jaw closes the opening in the passage groove of the second small-diameter section. The portion of the passage groove radially inward from the jaw forms a passage through which cooling air can flow. The blade cooling air passage extends through the root, shank, platform, and body. One end of this blade cooling air passage opens at the bottom surface of the root, and the other end opens at the wing surface of the body.

[0011] In this final stage disk unit, cooling air is supplied to the main cooling air passage in the rear shaft section. The cooling air flows from the main cooling air passage through the first radial passage and the axial passage of the first small diameter section to the second radial passage of the second small diameter section. From this second radial passage, the cooling air flows into the blade groove through the passage formed by the passage groove of the second small diameter section and the jaw portion of the rotor blade. The cooling air that has flowed into the blade groove flows into the blade cooling air passage of the rotor blade, cooling the rotor blade. [Prior art documents] [Patent Documents]

[0012] [Patent Document 1] Japanese Patent Publication No. 2009-243312 [Overview of the Initiative] [Problems that the invention aims to solve]

[0013] The rotor blade body is subjected to forces from the high-temperature, high-pressure combustion gases that collide with it. Furthermore, the rotor blade root receives a force opposite to the force received by the rotor blade body from the rotor disk, preventing the blade from moving relative to the rotor disk. Additionally, the blade root also receives a force that counteracts the centrifugal force acting on the blade from the rotor disk.

[0014] To improve the performance of gas turbines, methods are being considered to increase the radial length of the blade, or in other words, to increase the blade height. Increasing the blade height increases the force the blade receives from the combustion gases, as well as the centrifugal force acting on the rotor blades. Therefore, increasing the blade height also increases the force the blade root receives from the rotor disk. To allow the blade root to withstand the force from the rotor disk, one method is to increase the axial length of the blade root. On the other hand, due to manufacturing considerations, it is desirable to keep the axial length of the rotor blades to a minimum.

[0015] Therefore, the present disclosure aims to provide a turbine rotor and a gas turbine equipped therewith that can increase the axial length of the portion of the rotor blade that receives force from the rotor disk while suppressing the overall axial length of the rotor blade. [Means for solving the problem]

[0016] A turbine rotor according to one embodiment of the invention for achieving the above objective is: The rotor comprises a rotor disk centered on an axis, a plurality of rotor blades attached to the rotor disk in a circumferential direction relative to the axis, and a cover member provided for each of the plurality of rotor blades and attached to the rotor disk. Each of the plurality of rotor blades has an airfoil-shaped cross-section perpendicular to the radial direction relative to the axis and extends in the radial direction, a platform provided at the end of the airfoil on the radially inner side of the airfoil, a shank provided on the radially inner side of the platform and extending in an inclined direction that forms a narrow angle with respect to the axis when viewed radially, a blade root provided on the radially inner side of the shank and extending in the inclined direction, and a blade cooling air passage formed in a continuous manner within the blade root, the shank, the platform, and the airfoil. The shank has a rear end face facing the downstream side of the axis, of the upstream side and the downstream side of the axis in the axial direction in which the axis extends. The blade root has a rear end face facing downstream of the axis and connected to the rear end face of the shank, and a base face facing radially inward, wherein the radially inward edge of the rear end face of the blade root is connected to the downstream edge of the base face. The downstream edge of the base face is at the same position as the rear end face of the shank in the axial direction, or is located upstream of the axis than the rear end face of the shank. The blade cooling air passage opens at the base face of the blade root and the blade surface of the blade body. The rotor disc has a cylindrical small-diameter portion centered on the axis and a large-diameter portion that is cylindrical centered on the axis and has an outer diameter larger than the outer diameter of the small-diameter portion. The small-diameter portion is connected to the downstream side of the large-diameter portion. The small-diameter portion has a passage groove for each of the plurality of rotor blades. The passage groove is recessed radially inward from the outer circumferential surface of the small-diameter portion, with its radially outer edge forming an opening, and extends in the inclined direction toward the large-diameter portion. The large-diameter portion has a blade groove for each of the plurality of rotor blades. The blade groove is recessed radially inward from the radially outer side so that the blade root can be inserted, extends in the inclined direction, and penetrates the large-diameter portion. The blade groove has a blade groove bottom surface that faces radially outward and is spaced radially apart from the root bottom surface of the blade root. The blade groove bottom surface is connected to the passage groove bottom surface, which is the bottom surface of the passage groove. The cover member closes the opening of the passage groove. The portion of the passage groove radially inward from the cover member forms a passage through which cooling air can flow and which connects to the blade groove of the large-diameter portion.

[0017] In this embodiment, cooling air flows into the blade cooling air passage of the rotor blade through a passage formed by the small-diameter passage groove and the cover member, and a passage formed between the root surface of the blade root and the bottom surface of the blade groove. As this cooling air flows through the blade cooling air passage, it cools the rotor blade and then flows out of the rotor blade through an opening formed on the blade surface. Therefore, in this embodiment, the rotor blade can be cooled with cooling air.

[0018] In this embodiment, the opening of the passage groove in the small-diameter section is closed by a cover member, which is a component independent of the rotor blade. Therefore, in this embodiment, the jaw portion that protrudes from the blade root toward the downstream axis, as in the rotor blade described in Patent Document 1, is unnecessary. Accordingly, the rotor blade in this embodiment has no jaw portion, the rear end surface of the blade root is connected to the rear end surface of the shank, and the radially inner edge of the rear end surface of the blade root is connected to the axially downstream edge of the root base surface.

[0019] Therefore, in this embodiment, even if the axial length of the blade root that receives force from the rotor disk within the rotor blade is increased, the axial length of the rotor blade can be kept down.

[0020] A gas turbine according to one embodiment of the invention for achieving the aforementioned objective is: The turbine rotor in the above aspect and a turbine casing covering the outer peripheral side of the turbine rotor are provided.

Advantages of the Invention

[0021] According to one aspect of the present disclosure, it is possible to suppress the axial length of the entire moving blade while increasing the axial length of the blade root, which is a part that receives force from the rotor disk in the moving blade.

Brief Description of the Drawings

[0022] [Figure 1] It is a schematic cross-sectional view of a gas turbine in an embodiment according to the present disclosure. [Figure 2] It is a cross-sectional view of a main part of a final-stage disk unit in an embodiment according to the present disclosure. [Figure 3] It is a detailed cross-sectional view of part III in FIG. 2. [Figure 4] It is an exploded view when the main part of the final-stage disk unit in an embodiment according to the present disclosure is developed in the circumferential direction and viewed from the radially outer side. [Figure 5] It is a cross-sectional view taken along line V-V in FIG. 3 with the lid member omitted. [Figure 6] It is a cross-sectional view taken along line V-V in FIG. 3 with the lid member not omitted. [Figure 7] It is an exploded perspective view of the main part of the final-stage disk unit in an embodiment according to the present disclosure.

Modes for Carrying Out the Invention

[0023] Hereinafter, embodiments of the turbine rotor of the present disclosure and a gas turbine including this turbine rotor will be described in detail with reference to the drawings.

[0024] As shown in FIG. 1, the gas turbine of the present embodiment includes a compressor 10 that compresses air A, a combustor 15 that burns fuel F in the air A compressed by the compressor 10 to generate combustion gas G, and a turbine 20 that is driven by the combustion gas G.

[0025] The compressor 10 includes a compressor rotor 13 that rotates around the axis Ar, a compressor casing 11 that covers the compressor rotor 13, and a plurality of stator blade rows 12. The turbine 20 includes a turbine rotor 23 that rotates around the axis Ar, a turbine casing 21 that covers the turbine rotor 23, and a plurality of stator blade rows 22. In the following, the direction in which the axis Ar extends will be called the axial direction Da, the circumferential direction around this axis Ar will simply be called the circumferential direction Dc, and the direction perpendicular to the axis Ar will be called the radial direction Dr. Also, one side of the axial direction Da will be called the upstream side Dau, and the opposite side will be called the downstream side Dad. Also, the side of the radial direction Dr that approaches the axis Ar will be called the inner radial direction Dri, and the opposite side will be called the outer radial direction Dr.

[0026] The compressor 10 is positioned on the axial upstream side Dau relative to the turbine 20.

[0027] The compressor rotor 13 and the turbine rotor 23 are located on the same axis Ar and are connected to each other to form a gas turbine rotor 3. For example, the rotor of a generator GEN is connected to this gas turbine rotor 3. The gas turbine further includes an intermediate casing 2. This intermediate casing 2 is located in the axial direction Da between the compressor casing 11 and the turbine casing 21. A combustor 15 is mounted on this intermediate casing 2. The compressor casing 11, the intermediate casing 2, and the turbine casing 21 are connected to each other to form a gas turbine casing 1.

[0028] The compressor rotor 13 has a rotor shaft 13r extending in the axial direction Da with respect to the axis Ar, and a plurality of rotor blade rows 13b attached to this rotor shaft 13r. The plurality of rotor blade rows 13b are arranged in the axial direction Da. Each rotor blade row 13b is composed of a plurality of rotor blades arranged in the circumferential direction Dc. One of a plurality of stator blade rows 12 is positioned at the downstream Da of each rotor blade row 13b along its axis. Each stator blade row 12 is located inside the compressor casing 11. Each stator blade row 12 is composed of a plurality of stator blades arranged in the circumferential direction Dc.

[0029] The turbine rotor 23 has a plurality of disk units 25 arranged in the axial direction Da, and spindle bolts 26 extending in the axial direction Da and connecting the plurality of disk units 25 to each other. One disk unit 25 has one rotor disk 27 and one rotor blade row 23b attached to the outer circumference of this rotor disk 27. One rotor blade row 23b has a plurality of rotor blades arranged in the circumferential direction Dc with respect to the axis Ar. The rotor disks 27 of each of the plurality of disk units 25 are connected to each other by the aforementioned spindle bolts 26 to form the rotor shaft 23r of the turbine rotor 23. A plurality of stator blade rows 22 are arranged in the axial direction Da and attached to the inner circumference side of the turbine casing 21. Each of the plurality of stator blade rows 22 is positioned on the axial upstream side Dau of one of the rotor blade rows 23b of the plurality of disk units 25. Each row of stator vanes 22 has multiple stator vanes arranged in the circumferential direction Dc with respect to the axis Ar.

[0030] Of the multiple disk units 25, the final stage disk unit 25f, which is the disk unit 25 furthest downstream of the axis Dad, has, as shown in Figures 2 and 3, a rotor disk 27f, a row of rotor blades 23b attached to this rotor disk 27f, multiple front seal plates 70, front seal plate retaining members 71, multiple rear seal plates 72, multiple cover members 80 for each rotor blade, and multiple cover retaining members 85 for each rotor blade. Note that Figure 3 is an enlarged view of part III in Figure 2.

[0031] The multiple rotor blades 50 constituting the rotor blade row 23b each have a blade body 51, a platform 52, a shank 61, and a blade root 65, as shown in Figures 4 to 7. Figure 4 is an exploded view of the main part of the final stage disk unit 25f, unfolded in the circumferential direction Dc and viewed from the radially outer direction Dro. Figure 5 is a cross-sectional view along the VV line in Figure 3 with the cover member 80 omitted. Figure 6 is a cross-sectional view along the VV line in Figure 3 with the cover member 80 included. Figure 7 is an exploded perspective view of the main part of the final stage disk unit 25f.

[0032] The wing body 51 has an airfoil shape with a cross section perpendicular to the radial direction Dr with respect to the axis Ar, and extends in the radial direction Dr.

[0033] The platform 52 is located at the end of the airfoil 51 on the radially inward Dri. As shown in Figures 3, 4, and 7, the platform 52 has a gas path surface 53, an anti-gas path surface 54, a front end surface 55 (see Figures 4 and 7), a rear end surface 56, and a pair of side surfaces 57. The gas path surface 53 faces radially outward Dro. The airfoil 51 extends radially outward Dro from this gas path surface 53. The anti-gas path surface 54 is back-to-back with the gas path surface 53 and faces radially inward Dri. The front end surface 55 extends radially in Dr and circumferentially in Dc and faces upstream of the axis Dau. The rear end surface 56 is back-to-back with the front end surface 55. This rear end surface 56 extends radially in Dr and circumferentially in Dc and faces downstream of the axis Dad. The rear end surface 56 is parallel to the front end surface 55. Both of the pair of side surfaces 57 extend radially in the Dr and in the inclination direction Di, and face circumferentially in the Dc direction. The inclination direction Di is the direction that forms a narrow angle with respect to the axis Ar, as shown in Figure 4. The pair of side surfaces 57 are parallel to each other. Therefore, when viewed from the radial direction Dr, the platform 52 has a parallelogram shape. The platform 52 further has a front seal plate groove 58 and a rear seal plate groove 59. The front seal plate groove 58 is formed in the part of the platform 52 closer to the front end surface 55. The rear seal plate groove 59 is formed in the part of the platform 52 closer to the rear end surface 56. Both the front seal plate groove 58 and the rear seal plate groove 59 are recessed radially outward from the anti-gas pass surface 54 toward Dr and extend in the circumferential direction Dc.

[0034] The shank 61 is located on the radially inward Dri of the platform 52 and extends in the inclined direction Di. The shank 61 has a front end face 62 (see Figure 7), a rear end face 63, and a pair of side faces 64. The front end face 62 widens radially in the Dr and circumferentially in the Dc direction and faces upstream of the axis Dau. The rear end face 63 is back-to-back with the front end face 62. This rear end face 63 widens radially in the Dr and circumferentially in the Dc direction and faces downstream of the axis Dad. The rear end face 63 is parallel to the front end face 62. The pair of side faces 64 both widen radially in the Dr and circumferentially in the Di direction and face circumferentially in the Dc direction. The distance between the pair of side faces 64 in the circumferential direction Dc gradually narrows towards the radially inward Dri, as shown in Figure 5.

[0035] The wing root 65 is located radially inward Dri of the shank 61 and extends in the inclined direction Di. The wing root 65 has a front end face 66 (see Figure 7), a rear end face 67, a base face 65b, and a pair of side faces 68. The front end face 66 extends radially Dr and circumferentially Dc and faces upstream Dau along the axis. The rear end face 67 is back-to-back with the front end face 66. This rear end face 67 extends radially Dr and circumferentially Dc and faces downstream Dad along the axis. The rear end face 67 is parallel to the front end face 66. This rear end face 67 is connected to the rear end face 63 of the shank 61. The base face 65b is located radially inward Dri on the wing root 65 and faces radially inward Dri. The edge of the base surface 65b on the upstream side Dau of the axis is connected to the radially inner edge Dri of the front end surface 66 of the wing root 65. Similarly, the edge of the base surface 65b on the downstream side Da is connected to the radially inner edge Dri of the rear end surface 67 of the wing root 65. Furthermore, the downstream side Da of the base surface 65b is located in the same position as the rear end surface 63 of the shank 61 in the axial direction Da, or is located on the axially upstream side Dau than the rear end surface 63 of the shank 61. Both of the pair of side surfaces 68 extend radially in the Dr direction and in the inclination direction Di. As shown in Figure 5, the wing root 65 is formed such that the width between the pair of side surfaces 68 alternates between large and small sections. In other words, the cross-sectional shape of the wing root 65 perpendicular to the inclination direction Di is Christmas tree shaped. For the sake of the following explanation, the portion with the widest width between the pair of sides 68, specifically the portion with the innermost radial width Dri, will be referred to as the first wide portion 65f.

[0036] The rotor blade 50 further has a blade cooling air passage 69. The blade cooling air passage 69 extends within the blade root 65, shank 61, platform 52, and blade body 51. One end of the blade cooling air passage 69 opens at the base surface 65b of the blade root 65, and the other end opens at the blade surface of the blade body 51.

[0037] As shown in Figure 2, the rotor disk 27f of the final stage disk unit 25f has a cylindrical rear shaft portion 28 centered on the axis Ar, a first small diameter portion 31 that is cylindrical centered on the axis Ar and has an outer diameter larger than the outer diameter of the rear shaft portion 28, a second small diameter portion 34 that is cylindrical centered on the axis Ar and has an outer diameter larger than the outer diameter of the first small diameter portion 31, and a large diameter portion 41 that is cylindrical centered on the axis Ar and has an outer diameter larger than the outer diameter of the second small diameter portion 34. The first small diameter portion 31 is connected to the upstream side Dau of the axis of the rear shaft portion 28. The second small diameter portion 34 is connected to the upstream side Dau of the axis of the first small diameter portion 31. The large diameter portion 41 is connected to the upstream side Dau of the axis of the axis of the second small diameter portion 34.

[0038] The rear shaft portion 28 has a main cooling air passage 29 through which cooling air Ac can flow. The main cooling air passage 29 extends from the rear end face (not shown) of the rear shaft portion 28 toward the upstream side Dau of the axis into the second small diameter portion 34.

[0039] The first small-diameter section 31 has a plurality of first radial passages 32 and a plurality of axial passages 33. The first radial passages 32 extend radially Dr within the first small-diameter section 31. The radially inner end Dri of these first radial passages 32 is connected to the axially upstream end Dau of the main cooling air passage 29. The axial passages 33 extend from the radially outer end Dro of the first radial passages 32 toward the axially upstream end Dau into the first small-diameter section 31.

[0040] The second small-diameter section 34 (hereinafter sometimes simply referred to as the small-diameter section) has a plurality of second radial passages 35, a plurality of passage grooves 36, a seal plate groove 37, and a lid retaining groove 38, as shown in Figures 3 to 7. The plurality of second radial passages 35 and the plurality of passage grooves 36 are present for each of the plurality of rotor blades 50. The second radial passage 35 (hereinafter sometimes simply referred to as the radial passage) extends radially Dr within the second small-diameter section 34. The radially inner end Dri of this second radial passage 35 is connected to the axial upstream end Dau of the axial passage 33 in the first small-diameter section 31. The passage groove 36 is recessed radially inward Dri from the outer circumferential surface of the second small-diameter section 34, with its radially outer edge Dro forming an opening, and extends in an inclined direction Di toward the axial upstream end Dau from the radially outer end Dro of the second radial passage 35. The seal plate groove 37 is formed in the second small diameter section 34 at the boundary with the large diameter section 41. This seal plate groove 37 is recessed from the radially outer Dro to the radially inner Dri and extends in the circumferential direction Dc. The groove depth of this seal plate groove 37 is shallower than the groove depth of the passage groove 36. The lid retaining groove 38 is formed in the second small diameter section 34 at a position Da downstream of the axis of the multiple second radial passages 35. This lid retaining groove 38 is recessed from the radially outer Dro to the radially inner Dri and extends in the circumferential direction Dc. The groove depth of this seal plate groove 37 is also shallower than the groove depth of the passage groove 36.

[0041] The large-diameter section 41 has a wing groove 42 for each of the multiple rotor blades 50. The wing groove 42 is recessed radially inward Dri from the outer circumferential surface 41o of the large-diameter section 41, extends in the inclination direction Di, and penetrates the large-diameter section 41. The wing groove 42 has a Christmas tree shape in its cross-sectional shape perpendicular to the inclination direction Di, similar to the wing root 65, so that the wing root 65 of the rotor blade 50 can be fitted into it. Here, for the sake of the following explanation, the portion with the largest width between the sides of a pair of grooves, the portion with the largest radial inward Dri, will be called the first wide section 42f. The surface of this first wide section 42f that is located with the largest radial inward Dri and faces radial inward Dri forms the wing groove bottom surface 42b of this wing groove 42. The radial Dr dimension of the first wide section 42f of the wing groove 42 is larger than the radial Dr dimension of the first wide section 65f of the wing root 65. Therefore, when the wing root 65 is fitted into the wing groove 42, an inclined passage 43 is formed between the root base surface 65b and the wing groove base surface 42b, which is a passage through which cooling air can flow. The cross-sectional shape of the passage groove 36 in the second small diameter section 34 perpendicular to the inclination direction Di matches the cross-sectional shape of the first wide section 42f in the wing groove 42 perpendicular to the inclination direction Di, and the passage groove base surface 36b, which is the bottom surface of the passage groove 36, is connected to the wing groove base surface 42b.

[0042] As shown in Figure 2, the front seal plate 70 faces the front end faces 62 of the shanks 61 of the multiple rotor blades 50 and extends in the circumferential direction Dc, so as to be able to seal the portion of the shank 61 between each of the multiple rotor blades 50 on the upstream side Dau of the axis. The radially outer portion Dro of this front seal plate 70 fits into the front seal plate groove 58 of the platform 52. The radially inner portion Dri of this front seal plate 70 is restrained by the front seal plate retaining member 71 so as to be unable to move relative to the rotor disc 27f.

[0043] The rear seal plate 72 has a plate body 73 and a projection 74. The plate body 73 faces the rear end face 63 of the shank 61 and extends in the circumferential direction Dc, so that it can seal the portion of the axis downstream Da between the shanks 61 of each of the multiple rotor blades 50. The projection 74 protrudes radially inward from a part of the edge of the radially inward Dri of the plate body 73. The radially outward Dro portion of the plate body 73 fits into the rear seal plate groove 59 of the platform 52. The radially outward Dro portion of the plate body 73 also fits into the seal plate groove 37 of the second small diameter portion 34.

[0044] The cover member 80 is a component independent of the rotor blade 50 and is a component that fits into the passage groove 36 of the second small diameter portion 34 and closes the opening 36o of the passage groove 36. As mentioned above, the passage groove 36 is a groove that extends in the inclined direction Di. Therefore, the cover member 80 is also a component that extends in the inclined direction Di. The cover member 80 has a front end surface 81 facing the upstream side Dau of the axis, a rear end surface 82 facing the downstream side Dad of the axis, a cover bottom surface 80b facing the radially inward Dri, and a seal plate movement restricting groove 83. When the cover member 80 is fitted into the passage groove 36 and closing the opening 36o of the passage groove 36, the front end surface 81 of the cover member 80 faces the portion of the first wide portion 65f in the inclined direction Di within the rear end surface 67 of the blade root 65. Furthermore, in this state, the cover bottom surface 80b becomes substantially flush with the root bottom surface 65b. Furthermore, the cross-sectional shape of the lid member 80 perpendicular to the inclination direction Di corresponds to the cross-sectional shape of the first wide portion 65f of the wing root 65 perpendicular to the inclination direction Di. As mentioned above, the cross-sectional shape of the passage groove 36 perpendicular to the inclination direction Di coincides with the cross-sectional shape of the first wide portion 42f of the wing groove 42 perpendicular to the inclination direction Di. Therefore, when the lid member 80 is fitted into the passage groove 36, a passage in the inclination direction 39 is formed between the lid bottom surface 80b and the passage groove bottom surface 36b, allowing cooling air to flow and communicating with the inclination direction passage 43 between the root bottom surface 65b and the wing groove bottom surface 42b. Moreover, when the lid member 80 is fitted into the passage groove 36 of the second small diameter portion 34, the lid member 80 can no longer move relative to the second small diameter portion 34 radially outward Dro.

[0045] The seal plate movement restricting groove 83 of the lid member 80 is formed at a position Dau on the upstream side of the axis within the lid member 80. This seal plate movement restricting groove 83 is recessed from the radially outward Dro to the radially inward Dri so that the protrusion 74 of the rear seal plate 72 can fit into it. When the lid member 80 is fitted into the passage groove 36 and the opening 36o of the passage groove 36 is closed, this seal plate movement restricting groove 83 is formed at the same position as the rear seal plate groove 59 of the second small diameter portion 34 in the axial direction Da. When the lid member 80 is fitted into the passage groove 36 and the opening 36o of the passage groove 36 is closed, the bottom surface of this seal plate movement restricting groove 83 is located radially inward Dri than the bottom surface of the seal plate groove 37 of the second small diameter portion 34.

[0046] The lid retaining member 85 has a first retaining member 86 present for each of the multiple rotor blades 50, a multiple second retaining member 87, and a spacing changing member 88 present for each of the multiple rotor blades 50. The first retaining member 86 is a plate-shaped member that can contact the rear end surface 82 of the lid member 80. The second retaining member 87 is a plate-shaped member that extends in the circumferential direction Dc and is positioned on the downstream side Da of the axis of the first retaining member 86. The spacing changing member 88 is a male screw. The first retaining member 86 and the second retaining member 87 each have female screws 86s and 87s that penetrate in the axial direction Da and into which the male screw spacing changing member 88 can be screwed. However, the female screw 87s of the second retaining member 87 is a reverse thread with respect to the female screw 86s of the first retaining member 86. Therefore, after screwing the male threaded spacing member 88 into the female threads 86s of the first fastening member 86 and the female threads 87s of the second fastening member 87, rotating the male threaded spacing member 88 changes the axial spacing Da between the first fastening member 86 and the second fastening member 87.

[0047] Next, we will explain the assembly sequence of the final stage disk unit 25f described above. First, the blade groove 42 of the rotor disc 27f and the blade root 65 of the rotor blade 50 are aligned in the axial direction Da. Then, the rotor blade 50 is moved in the inclined direction Di so that the blade root 65 of the rotor blade 50 fits into the blade groove 42 of the rotor disc 27f.

[0048] Next, the front seal plate 70 and the rear seal plate 72 are attached to the rotor disc 27f. When attaching the rear seal plate 72, the rear seal plate 72 is moved in the circumferential direction Dc so that the radially outer Dro portion of the plate body 73 of the rear seal plate 72 is fitted into the rear seal plate groove 59 of the rotor blade 50, and the radially inner Dri portion of the plate body 73 of the rear seal plate 72 is fitted into the seal plate groove 37 of the second small diameter portion 34. At this time, the rear seal plate 72 is moved in the circumferential direction Dc so that the protruding portion 74 of the rear seal plate 72 is in the same position as the passage groove 36 of the second small diameter portion 34 in the circumferential direction Dc.

[0049] Next, the front end surface 81 of the lid member 80 and the passage groove 36 of the second small diameter portion 34 are brought into opposition in the axial direction Da. Then, the lid member 80 is moved in the inclined direction Di to fit the lid member 80 into the passage groove 36, and the front end surface 81 of the lid member 80 is brought into opposition with the rear end surfaces 63 and 67 of the wing root 65 in the axial direction Da. When the lid member 80 is fitted into the passage groove 36, the lid member 80 becomes immobile in the radial direction Dr relative to the second small diameter portion 34. Also, when the lid member 80 is fitted into the passage groove 36, the protruding portion 74 of the rear seal plate 72 is contained within the seal plate movement restricting groove 83 of the lid member 80, and the rear seal plate 72 becomes immobile in the circumferential direction Dc. As described above, in this embodiment, the rear seal plate 72 can be made immobile in the circumferential direction Dc with a simple configuration and a simple assembly sequence.

[0050] Next, the spacing-changing member 88, which is a male screw, is screwed into the female threads 86s of the first stopping member 86 and the female threads 87s of the second stopping member 87 so that the gap between the first stopping member 86 and the second stopping member 87 is minimized, thereby connecting the first stopping member 86 and the second stopping member 87 with the spacing-changing member 88. Next, the first stopping member 86 and the second stopping member 87, which are connected by the spacing-changing member 88, are placed into the lid-retaining groove 38 of the second small-diameter section 34. Then, the spacing-changing member 88, which is a male screw, is rotated to widen the gap between the first stopping member 86 and the second stopping member 87, bringing the first stopping member 86 into contact with the rear end surface 82 of the lid member 80, and bringing the front end surface 81 of this lid member 80 into contact with the rear end surface 67 of the wing root 65. As a result, the lid member 80 becomes immobile in the inclined direction Di.

[0051] This completes the assembly of the final stage disk unit 25f.

[0052] At the radially outer Dro of the platform 52 and the radially inner Dri of the turbine casing 21, combustion gas G from the combustor 15 flows into the annular combustion gas flow path of the rotor blade 50 for each of the multiple rotor blade rows 23b. The blade bodies 51 of the rotor blade 50 are located within this combustion gas flow path.

[0053] In this final stage disk unit 25f, cooling air Ac is supplied into the main cooling air passage 29 of the rear shaft section 28. The cooling air Ac flows from the main cooling air passage 29 through the first radial passage 32 and the axial passage 33 of the first small diameter section 31 into the second radial passage 35 of the second small diameter section 34. From this second radial passage 35, the cooling air Ac flows through the inclined passage 39 formed by the passage groove 36 of the second small diameter section 34 and the cover member 80 into the inclined passage 43 in the blade groove 42. The cooling air Ac that has flowed into the inclined passage 43 in the blade groove 42 flows into the blade cooling air passage 69 of the rotor blade 50, cooling the blade body 51 of the rotor blade 50.

[0054] In this embodiment, the opening 36o of the passage groove 36 of the small diameter portion 34 is closed by a cover member 80, which is a component independent of the rotor blade 50. Therefore, in this embodiment, the jaw portion that protrudes from the blade root toward the downstream side Dad of the axis, as in the rotor blade described in Patent Document 1, is unnecessary. Accordingly, the rotor blade 50 in this embodiment has no jaw portion, the rear end surface 67 of the blade root 65 is connected to the rear end surface 63 of the shank 61, and the radially inner edge Dri of the rear end surface 67 of the blade root 65 is connected to the downstream side Dad of the root surface 65b of the blade root 65.

[0055] Therefore, in this embodiment, even if the length of the axial Da of the blade root 65 that receives force from the rotor disk 27f within the rotor blade 50 is increased, the length of the axial Da of the rotor blade 50 can be kept down.

[0056] This disclosure is not limited to the embodiments described above. Various additions, modifications, substitutions, partial deletions, etc., are possible without departing from the conceptual idea and spirit of the present invention derived from the claims and their equivalents.

[0057] "Addendum" The turbine rotor in the above embodiments can be understood, for example, as follows.

[0058] (1) The turbine rotor in the first embodiment is The system comprises a rotor disk 27f centered on an axis Ar, a plurality of rotor blades 50 attached to the rotor disk 27f and aligned in the circumferential direction Dc with respect to the axis Ar, and a cover member 80 provided for each of the plurality of rotor blades 50 and attached to the rotor disk 27f. Each of the plurality of rotor blades 50 has an airfoil-shaped cross-section perpendicular to the radial direction Dr with respect to the axis Ar, and includes a blade body 51 extending in the radial direction Dr, a platform 52 provided at the end of the blade body 51 on the radially inner Dri side of the radial direction Dr, a shank 61 provided on the radially inner Dri side of the platform 52 and extending in an inclined direction Di which forms a narrow angle with respect to the axis Ar when viewed radially, a blade root 65 provided on the radially inner Dri side of the shank 61 and extending in the inclined direction Di, and a blade cooling air passage 69 formed in a continuous manner within the blade root 65, the shank 61, the platform 52, and the blade body 51. The shank 61 has a rear end face 63 facing the downstream side Da of the axis, which is one of the two sides of the axis in the axial direction Da to which the axis Ar extends, Dau on the upstream side and Da on the downstream side. The blade root 65 has a rear end surface 67 facing the downstream side Da of the axis and connected to the rear end surface 63 of the shank 61, and a base surface 65b facing the radially inward Dri. The radially inward Dri edge of the rear end surface 67 of the blade root 65 is connected to the downstream side Da of the base surface 65b. The downstream side Da of the base surface 65b is in the same position as the rear end surface 63 of the shank 61 in the axial direction Da, or is located upstream Dau of the axis than the rear end surface 63 of the shank 61. The blade cooling air passage 69 opens at the base surface 65b of the blade root 65 and the blade surface of the blade body 51. The rotor disc 27f has a cylindrical small-diameter portion 34 centered on the axis Ar, and a large-diameter portion 41 that is cylindrical centered on the axis Ar and has an outer diameter larger than the outer diameter of the small-diameter portion 34. The small-diameter portion 34 is connected to the Dad on the downstream side of the axis of the large-diameter portion 41. The small-diameter portion 34 has a passage groove 36 for each of the plurality of rotor blades 50. The passage groove 36 is recessed from the outer circumferential surface of the small-diameter portion 34 radially inward Dri, with the edge of the radially outward Dro forming an opening 36o, and extends toward the large-diameter portion 41 in the inclined direction Di. The large-diameter portion 41 has a blade groove 42 for each of the plurality of rotor blades 50. The blade groove 42 is recessed from the radially outward Dro to the radially inward Dri so that the blade root 65 can be inserted, extends in the inclined direction Di, and penetrates the large-diameter portion 41. The blade groove 42 has a blade groove bottom surface 42b that faces radially outward in the Dr direction and is separated from the root bottom surface 65b of the blade root 65 by a distance in the radial direction in the Dr direction. The blade groove bottom surface 42b is connected to the passage groove bottom surface 36b, which is the bottom surface of the passage groove 36. The cover member 80 closes the opening 36o of the passage groove 36. In the passage groove 36, the portion radially inward in the Dr direction from the cover member 80 forms a passage 39 through which cooling air Ac can flow and which is connected to the blade groove 42 of the large diameter portion 41.

[0059] In this embodiment, cooling air Ac flows into the blade cooling air passage 69 of the rotor blade 50 via a passage 39 formed by the passage groove 36 of the small diameter portion 34 and the cover member 80, and a passage 43 formed between the base surface 65b of the blade root 65 and the base surface 42b of the blade groove 42. As this cooling air Ac flows through the blade cooling air passage 69, it cools the rotor blade 50 and then flows out of the rotor blade 50 through an opening formed on the blade surface of the rotor blade 50. Therefore, in this embodiment, the rotor blade 50 can be cooled by the cooling air Ac.

[0060] In this embodiment, the opening 36o of the passage groove 36 of the small diameter portion 34 is closed by a cover member 80, which is a component independent of the rotor blade 50. Therefore, in this embodiment, the jaw portion that protrudes from the blade root toward the downstream side Dad of the axis, as in the rotor blade described in Patent Document 1, is unnecessary. Accordingly, the rotor blade 50 in this embodiment has no jaw portion, the rear end surface 67 of the blade root 65 is connected to the rear end surface 63 of the shank 61, and the radially inner edge Dri of the rear end surface 67 of the blade root 65 is connected to the downstream side Dad of the root surface 65b of the blade root 65.

[0061] Therefore, in this embodiment, even if the length of the axial Da of the blade root 65 that receives force from the rotor disk 27f within the rotor blade 50 is increased, the length of the axial Da of the rotor blade 50 can be kept down.

[0062] (2) The turbine rotor in the second embodiment is In the turbine rotor 23 according to the first embodiment, the small-diameter portion 34 has a radial passage 35 for each of the plurality of rotor blades 50. The radial passage 35 extends radially in the Dr direction within the small-diameter portion 34 so that cooling air Ac can flow through it. The passage groove 36 extends in the inclined direction Di toward the large-diameter portion 41 from the radially outer end of the radial passage 35 toward the large-diameter portion 41.

[0063] (3) The turbine rotor in the third embodiment is In the turbine rotor 23 according to the first or second embodiment, a rear seal plate 72 is provided, having a plate body 73 that faces the rear end face 63 of the shank 61 of the plurality of rotor blades 50 and extends in the circumferential direction Dc, and closes the portion Dad on the downstream side of the axis between the shank 61 of each of the plurality of rotor blades 50. The radially outer portion Dro of the rear seal plate 72 is in contact with the platform 52, and the radially inner portion Dri of the rear seal plate 72 is in contact with the cover member 80.

[0064] In this embodiment, it is possible to suppress the flow of combustion gas G that has entered between the shanks 61 of adjacent rotor blades 50 in the circumferential direction Dc, from this point to the downstream side Dad along the axis.

[0065] (4) The turbine rotor in the fourth embodiment is In the turbine rotor 23 of the third embodiment, the rear seal plate 72 has a plate body 73 and a projection 74 that protrudes from a part of the edge of the radially inner Dri of the plate body 73 toward the radially inner Dri. The platform 52 has a rear seal plate groove 59 that is recessed from the radially inner Dri toward the radially outer Dro and extends toward the circumferential Dc, into which the portion of the radially outer Dro of the plate body 73 fits. The cover member 80 has a seal plate movement restricting groove 83 that is recessed from the radially outer Dro toward the radially inner Dri, into which the projection 74 of the rear seal plate 72 fits, restricting the movement of the rear seal plate 72 toward the circumferential Dc.

[0066] When assembling the turbine rotor 23, in this embodiment, first, the blade roots 65 of the rotor blades 50 are placed in the blade grooves 42 of the large-diameter section 41. Next, the radially outer portion Dro of the plate body 73 of the rear seal plate 72 is placed in the rear seal plate groove 59 of the rotor blade 50. Then, the rear seal plate 72 is moved in the circumferential direction Dc so that the protruding portion 74 of the rear seal plate 72 is positioned in the passage groove 36. After that, the opening 36o of the passage groove 36 is closed with the cover member 80. The protruding portion 74 of the rear seal plate 72 fits into the seal plate movement restricting groove 83 of the cover member 80 that has closed the opening 36o of the passage groove 36, and the movement of the rear seal plate 72 in the circumferential direction Dc is suppressed. As described above, in this embodiment, the movement of the rear seal plate 72 in the circumferential direction Dc can be suppressed with a simple configuration and a simple assembly sequence.

[0067] (5) The turbine rotor in the fifth embodiment is In the turbine rotor 23 in any one of the first to fourth embodiments, a lid retaining member 85 is provided that contacts the rear end surface 82 of the lid member 80 facing the downstream Dad of the axis, and restricts the movement of the lid member 80 toward the downstream Dad of the axis relative to the rotor disk 27f. The small diameter portion 34 of the rotor disk 27f has a lid retaining groove 38 that is recessed from the radially outer Dro toward the radially inner Dri, into which the lid retaining member 85 fits.

[0068] This embodiment can suppress the movement of the lid member 80 toward the downstream side Dad along the axis.

[0069] (6) The turbine rotor in the sixth embodiment is In the turbine rotor 23 of the fifth embodiment, the lid retaining member 85 includes a first retaining member 86 that can contact the rear end surface 82 of the lid member 80, a second retaining member 87 positioned on the downstream side Da of the axis of the first retaining member 86, and a spacing changing member 88 that can change the spacing between the first retaining member 86 and the second retaining member 87 in the axial direction Da.

[0070] The gas turbine in the above embodiments can be understood, for example, as follows: (7) The gas turbine in the seventh embodiment is The turbine comprises a turbine rotor 23 according to any one of the first to sixth embodiments, and a turbine casing 21 covering the outer circumference of the turbine rotor 23. [Explanation of Symbols]

[0071] 1: Gas turbine casing 2: Intermediate casing 3: Gas turbine rotor 10: Compressor 11: Compressor casing 12: Stator Wing Arrow 13: Compressor rotor 13b: Moving blade row 13r: Rotor shaft 15: Combustor 20: Turbine 21: Turbine casing 22: Static Wing Arrow 23: Turbine rotor 23b: Moving blade row 23r: Rotor shaft 25: Disk Unit 25f: Final stage disk unit 26: Spindle bolt 27: Rotor Disc 27f: (Final stage) rotor disc 28: Rear shaft part 29: Main cooling air passage 31:First small diameter section 32: First radial passage 33: Axial passage 34: Second small diameter section (or simply small diameter section) 35: Second radial passage (or simply radial passage) 36: Passage groove 36b: Passage groove bottom surface 36o: opening 37: Seal plate groove 38: Cover retaining groove 39: Slope direction passage 41: Large diameter section 41o: Outer surface 42: Wing groove 42b: Bottom surface of wing groove 42f: First wide section 43: Slope direction passage 50: Moving blade 51: Wing body 52: Platform 53: Gas Pass Surface 54: Anti-gas path surface 55: Front end surface 56: Rear end surface 57: Side view 58: Front seal plate groove 59: Rear seal plate groove 61: Shank 62: Front end surface 63: Rear end surface 64: Side view 65: Wing root 65b: Fundamental surface 65f: First wide section 66: Front end surface 67: Rear end surface 68: Side view 69: Wing cooling air passage 70: Front sealing plate 71: Front seal plate fastening member 72: Rear sealing plate 73: Main body of the board 74:Protrusion 80: Lid component 80b: Lid bottom 81: Front end surface 82: Rear end surface 83: Seal plate movement regulating groove 85: Lid retaining member 86: First fastening member 86s: Female thread 87: Second fastening member 87s: Female thread 88: Spacing adjustment member A: Air AC: Cooling air F:Fuel G: Combustion gas Ar: Axis line Da: Axial direction Dau: Axis upstream side Dad: Downstream side of the axis Dc: Circumferential direction Dr: Radial direction Dri: Radial inner side Dro: Radial outer side Di: Incline direction

Claims

1. A rotor disc centered on the axis, Multiple rotor blades mounted on the rotor disk are arranged in the circumferential direction with respect to the aforementioned axis, A cover member provided for each of the plurality of rotor blades and attached to the rotor disk, Equipped with, The aforementioned plurality of rotor blades are all, The airfoil body has a cross-section perpendicular to the radial direction with respect to the aforementioned axis, and extends in the radial direction. A platform provided at the end of the wing body on the radially inner side of the radial direction, A shank provided on the radially inward side of the platform, extending in an inclined direction which forms a narrow angle with respect to the axis when viewed radially, The shank is provided on the radially inward side and has a wing root extending in the direction of inclination, The wing root, the shank, the platform, and the wing cooling air passage formed in connection within the wing body, It has, The shank has a rear end face that faces the downstream side of the axis, among the upstream and downstream sides of the axis in the axial direction in which the axis extends. The wing root has a rear end surface facing downstream of the axis and connected to the rear end surface of the shank, and a base surface facing radially inward, wherein the radially inward edge of the rear end surface of the wing root is connected to the downstream edge of the base surface. The downstream edge of the base surface is in the same position as the rear end surface of the shank in the axial direction, or is located upstream of the rear end surface of the shank. The wing cooling air passage opens at the root surface of the wing root and the wing surface of the wing body, The rotor disc has a cylindrical small-diameter portion centered on the axis and a cylindrical large-diameter portion centered on the axis with an outer diameter larger than the outer diameter of the small-diameter portion. The small diameter portion is connected to the downstream side of the axis of the large diameter portion, The small diameter portion has a passage groove for each of the plurality of rotor blades, The passage groove is recessed radially inward from the outer circumferential surface of the small diameter portion, with its radially outer edge forming an opening, and extends toward the large diameter portion in the inclined direction. The aforementioned large-diameter section has a blade groove for each of the multiple rotor blades. The wing groove is recessed from the radially outer to the radially inward so that the wing root can be inserted, extends in the inclined direction and penetrates the large diameter portion. The wing groove has a wing groove bottom surface that faces radially outward and is separated radially from the root surface of the wing root, The bottom surface of the wing groove is connected to the bottom surface of the passage groove, The cover member closes the opening of the passage groove, In the passage groove, the portion radially inward from the cover member forms a passage through which cooling air can flow and which connects to the blade groove in the large-diameter portion. Turbine rotor.

2. In the turbine rotor according to claim 1, The small diameter portion has a radial passage for each of the plurality of rotor blades, The radial passage extends radially within the small diameter portion so that cooling air can flow through it. The passage groove extends in the inclined direction from the radially outer end of the radial passage toward the large diameter portion. Turbine rotor.

3. In the turbine rotor according to claim 1, The plurality of rotor blades are provided with a rear sealing plate having a plate body that faces the rear end surface of the shank and extends in the circumferential direction, and that closes the portion on the downstream side of the axis between the shanks of each of the plurality of rotor blades, The radially outer portion of the rear seal plate is in contact with the platform, and the radially inner portion of the rear seal plate is in contact with the lid member. Turbine rotor.

4. In the turbine rotor according to claim 3, The aforementioned rear sealing plate has a plate body and a projection that protrudes radially inward from a part of the radially inward edge of the plate body, The platform has a rear seal plate groove that is recessed from the radially inward to the radially outward, extends in the circumferential direction, and into which the radially outward portion of the plate body fits. The lid member has a seal plate movement restricting groove that is recessed from the radially outer side to the radially inner side, into which the protruding portion of the rear seal plate fits, thereby restricting the circumferential movement of the rear seal plate. Turbine rotor.

5. In the turbine rotor according to any one of claims 1 to 4, The lid member is provided with a lid retaining member that contacts the rear end surface of the lid member facing downstream of the axis and restricts the movement of the lid member downstream of the axis relative to the rotor disk, The small diameter portion of the rotor disc has a recess extending from the radially outer side to the radially inner side, into which the lid retaining member fits. Turbine rotor.

6. In the turbine rotor according to claim 5, The lid retaining member comprises a first retaining member that can contact the rear end surface of the lid member, a second retaining member positioned downstream of the first retaining member along its axis, and a spacing changing member that can change the axial distance between the first retaining member and the second retaining member. Turbine rotor.

7. A turbine rotor according to any one of claims 1 to 4, A turbine casing that covers the outer circumference of the turbine rotor, A gas turbine equipped with a gas turbine.

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