Moving blade, and processing method for moving blade

Abstract

To provide a moving blade which suppresses a failure caused by creep deformation, and a processing method for a moving blade.SOLUTION: A moving blade comprises a shroud provided in an end of a blade body radially outside with respect to an axis. The shroud includes a shroud main body which is spread in a spread direction away from the blade body. The shroud main body includes a blade body connection region in which the blade body is connected and an outer edge side region which is formed outside of the blade body connection region in the spread direction. A gas path face of the blade body connection region is a curved face where a face change rate which is a ratio of a position change amount in a radial direction per unit position change amount in the spread direction becomes gradually small toward the spread direction. In a case where a change amount of a thickness which is an interval between the gas path face and an anti-gas-path face per unit position change amount in the spread direction is defined as a thickness change rate, an average thickness change rate in a specific outer edge side region in the outer edge side region is larger than a thickness change rate at a region edge in contact with the specific outer edge side region in the blade body connection region.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a moving blade and a method for machining a moving blade.

Background Art

[0002] A gas turbine, which is a type of axial flow rotary machine, includes a rotor that rotates about an axis and a casing that covers the rotor. The rotor has a rotor shaft and a plurality of moving blades attached to the rotor shaft.

[0003] For example, the moving blade described in Patent Document 1 below has a blade body forming an airfoil shape and a shroud. The blade body extends in the radial direction with respect to the axis. The shroud is provided at the outer end of the blade body in the radial direction with respect to the axis.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] As described above, the shroud is provided at the outer end of the blade body in the radial direction. Therefore, an increase in the weight of the shroud leads to an increase in the centrifugal force acting on the blade body. When the centrifugal force increases, the amount of creep deformation that turns upward from the blade body to the outside in the radial direction in the shroud increases. As a result, problems such as a shortened life of the shroud occur.

[0006] An object of the present disclosure is to provide a moving blade that suppresses problems caused by creep deformation and a method for machining the moving blade.

Means for Solving the Problems

[0007] As a first aspect of the moving blade according to the present disclosure for achieving the above object, In a moving blade attached to a rotor shaft centered on an axis, a blade body extending in a radial direction with respect to the axis and having an airfoil cross-sectional shape orthogonal to the radial direction, and a shroud provided at an end on the outer side in the radial direction with respect to the axis in the blade body are provided. The blade body has a leading edge on the most upstream side in the axial direction in which the axis extends, a trailing edge on the most downstream side, a ventral surface and a dorsal surface connecting the leading edge and the trailing edge and facing each other. The shroud has a shroud body that extends in a direction having a component perpendicular to the radial direction in which the blade body extends and in a spreading direction away from the blade body. The shroud body has a blade body connection region including a region where the blade body is connected, and an outer edge side region connected to the blade body connection region and formed outside the blade body connection region in the spreading direction. Both the blade body connection region and the outer edge side region have a counter gas path surface facing the outer side in the radial direction and a gas path surface facing the inner side in the radial direction with respect to the axis. The gas path surface of the blade body connection region is a curved surface in which a surface change rate, which is a ratio of a position change amount in the radial direction per unit position change amount in the spreading direction, gradually decreases as it goes in the spreading direction. When the change amount of the thickness, which is the interval between the gas path surface and the counter gas path surface per unit position change amount in the spreading direction, is defined as a thickness change rate, the average thickness change rate in a specific outer edge side region in the outer edge side region is larger than the thickness change rate at the region edge in the blade body connection region that is in contact with the specific outer edge side region.

[0008] The outer edge side region has less rigidity compared to the blade body connection region and is likely to undergo creep deformation due to centrifugal force.

[0009] In this aspect, the gas path surface of the blade body connection region is a curved surface in which the surface change rate, which is the ratio of the radial position change amount per unit position change amount in the spreading direction, gradually decreases as it goes in the spreading direction. Further, the average thickness change rate in a specific outer edge side region in the outer edge side region is larger than the thickness change rate at the region edge in the blade body connection region that is in contact with the specific outer edge side region. For this reason, while smoothly connecting the outer edge side region and the blade body connection region, the outer edge side region becomes thinner than the blade body connection region. Thereby, while maintaining the aerodynamic characteristics, the outer edge side region can be lightened. Therefore, the centrifugal force applied to the outer edge side region of the shroud can be reduced, and the creep deformation that turns up radially outward can be suppressed. Accordingly, problems due to creep deformation can be suppressed.

[0010] As a second aspect of the present disclosure for achieving the above object, a moving blade is In a moving blade attached to a rotor shaft centered on an axis, a blade body extending in the radial direction with respect to the axis and having an airfoil cross-sectional shape perpendicular to the radial direction, and a shroud provided at an end portion on the outer side in the radial direction with respect to the axis in the blade body, wherein the blade body has a leading edge on the most upstream side in the axial direction in which the axis extends, among the upstream side and the downstream side in the axial direction, a trailing edge on the most downstream side, a ventral surface and a dorsal surface connecting the leading edge and the trailing edge and facing each other, the shroud has a shroud body extending in a direction having a component perpendicular to the radial direction in which the blade body extends and spreading in a spreading direction away from the blade body, the shroud body has a counter gas path surface facing the outer side in the radial direction, a gas path surface facing the inner side in the radial direction with respect to the axis, and an end surface connecting the edge of the counter gas path surface and the edge of the gas path surface, the end surface has a front end surface facing the upstream side in the axis, the front end surface has a first front end surface and a second front end surface, the first front end surface is located upstream of the leading edge with respect to the axis and spreads in the circumferential direction centered on the axis and in a direction perpendicular to the axis, and the second front end surface is a surface inclined with respect to the first front end surface so as to gradually face the downstream side in the axis as it goes in the side away from the blade body in the circumferential direction.

[0011] In this aspect, a second end face inclined with respect to the first end face is formed at the end of the shroud on the upstream side of the axis. Therefore, compared with the case where the front end face extends in a straight line in a direction perpendicular to the axis in a radial view, the volume of the shroud can be reduced, and the end of the shroud on the upstream side of the axis can be lightened. Thereby, the centrifugal force applied to the shroud can be reduced, and the creep deformation that turns up radially outward of the shroud can be suppressed. Therefore, problems due to creep deformation can be suppressed.

[0012] As a third aspect of the moving blade according to the present disclosure for achieving the above object, In a moving blade attached to a rotor shaft centered on an axis, there is a blade body that extends in a radial direction with respect to the axis and has an airfoil cross-sectional shape perpendicular to the radial direction, and a shroud provided at an end portion on the outer side in the radial direction with respect to the axis in the blade body. The blade body has a leading edge on the most upstream side in the axial direction in which the axis extends, a trailing edge on the most downstream side in the axial direction, a ventral surface and a dorsal surface that connect the leading edge and the trailing edge and are in a back-to-back relationship with each other. The shroud has a shroud body that extends in a direction having a component perpendicular to the radial direction in which the blade body extends and extends in a spreading direction away from the blade body. The shroud body has a reverse gas path surface facing the outer side in the radial direction, a gas path surface facing the inner side in the radial direction with respect to the axis, and an end surface connecting the edge of the reverse gas path surface and the edge of the gas path surface. The end surface has a dorsal end surface facing the circumferential dorsal side where the dorsal surface exists with respect to the ventral surface in the circumferential direction centered on the axis and located on the circumferential dorsal side of the blade body, and a ventral end surface facing the circumferential ventral side where the ventral surface exists with respect to the dorsal surface in the circumferential direction and located on the circumferential ventral side of the blade body. The dorsal end surface has a dorsal contact surface that can contact a part of the ventral end surface of another shroud located on the circumferential dorsal side of the shroud, and the ventral end surface has a ventral contact surface that can contact a part of the dorsal end surface of another shroud located on the circumferential ventral side of the shroud. The width in the radial direction of the ventral contact surface is smaller than the width in the radial direction of the dorsal contact surface.

[0013] The blade body tends to deform so as to fall from the circumferential ventral side to the circumferential dorsal side. For this reason, the end portion on the circumferential ventral side of the shroud approaches a stationary-side structure (for example, a honeycomb material) located on the outer side in the radial direction than the shroud. Further, due to creep deformation caused by centrifugal force, when the end portion on the circumferential ventral side of the shroud creeps and turns up on the outer side in the radial direction, there is a risk that the ventral contact surface of the shroud comes into heavy contact with this stationary-side structure.

[0014] In this aspect, the circumferential ventral end of the shroud can be thinned, and it is possible to suppress the ventral contact surface from making heavy contact with the stationary structure. Therefore, problems due to creep deformation can be suppressed.

[0015] As a first aspect of the present disclosure for achieving the above object, a method for machining a moving blade is In a method for machining a moving blade attached to a rotor shaft centered on an axis, the moving blade includes a blade body extending in a radial direction with respect to the axis and having an airfoil cross-sectional shape perpendicular to the radial direction, and a shroud provided at an end on the outer side in the radial direction with respect to the axis in the blade body. The blade body has a leading edge on the most upstream side of the axis in the axial direction in which the axis extends, a trailing edge on the most downstream side of the axis, a ventral surface and a dorsal surface connecting the leading edge and the trailing edge and facing each other. The shroud has a shroud body that extends in a direction having a component perpendicular to the radial direction in which the blade body extends and in a spreading direction away from the blade body. The shroud body has a blade body connection region including a region where the blade body is connected, and an outer edge side region connected to the blade body connection region and formed outside the blade body connection region in the spreading direction. Both the blade body connection region and the outer edge side region have a counter gas path surface facing the outer side in the radial direction and a gas path surface facing the inner side in the radial direction with respect to the axis. The gas path surface of the blade body connection region is a curved surface in which the surface change rate, which is the ratio of the position change amount in the radial direction per unit position change amount in the spreading direction, gradually decreases as it goes in the spreading direction. When the change amount of the thickness, which is the interval between the gas path surface and the counter gas path surface per unit position change amount in the spreading direction, is defined as the thickness change rate, at least one of the counter gas path surface and the gas path surface in the specific outer edge side region in the outer edge side region is machined so that the average thickness change rate in the specific outer edge side region in the outer edge side region is larger than the thickness change rate at the region edge in the blade body connection region that is in contact with the specific outer edge side region.

[0016] As a second aspect of the present disclosure for achieving the above object, a method for machining a moving blade is as follows: In a method for machining a moving blade attached to a rotor shaft centered on an axis, the moving blade includes a blade body that extends in a radial direction with respect to the axis and has an airfoil shape in a cross-sectional shape perpendicular to the radial direction, and a shroud provided at an end portion on the outer side in the radial direction with respect to the axis in the blade body. The blade body has a leading edge on the most upstream side of the axis in the axial direction in which the axis extends, a trailing edge on the most downstream side of the axis, a ventral surface and a dorsal surface that connect the leading edge and the trailing edge and are in a back-to-back relationship. The shroud has a shroud body that extends in a direction having a component perpendicular to the radial direction in which the blade body extends and in a spreading direction away from the blade body. The shroud body has a reverse gas path surface facing the outer side in the radial direction, a gas path surface facing the inner side in the radial direction with respect to the axis, and an end surface connecting the edge of the reverse gas path surface and the edge of the gas path surface. The end surface has a front end surface facing the upstream side of the axis, and the front end surface has a first front end surface and a second front end surface. The first front end surface is located upstream of the axis with respect to the leading edge and extends in a circumferential direction centered on the axis and in a direction perpendicular to the axis. The front end surface is machined such that the second front end surface is inclined with respect to the first front end surface so as to gradually face the downstream side of the axis as it moves away from the blade body in the circumferential direction.

[0017] As a third aspect of the present disclosure for achieving the above object, a method for machining a moving blade is as follows: In a method for machining a moving blade attached to a rotor shaft centered on an axis, the moving blade includes a blade body that extends in a radial direction with respect to the axis and has an airfoil-shaped cross-sectional shape perpendicular to the radial direction, and a shroud provided at an end portion on the outer side in the radial direction with respect to the axis in the blade body. The blade body has a leading edge on the most upstream side in the axial direction in which the axis extends, a trailing edge on the most downstream side in the axial direction, a ventral surface and a dorsal surface that connect the leading edge and the trailing edge and are in a back-to-back relationship. The shroud has a shroud body that extends in a direction having a component perpendicular to the radial direction in which the blade body extends and in a spreading direction away from the blade body. The shroud body has a counter gas path surface facing the outer side in the radial direction, a gas path surface facing the inner side in the radial direction with respect to the axis, and an end surface connecting the edge of the counter gas path surface and the edge of the gas path surface. The end surface has a dorsal end surface facing the circumferential dorsal side where the dorsal surface exists with respect to the ventral surface in the circumferential direction centered on the axis and located on the circumferential dorsal side of the blade body, and a ventral end surface facing the circumferential ventral side where the ventral surface exists with respect to the dorsal surface in the circumferential direction and located on the circumferential ventral side of the blade body. The dorsal end surface has a dorsal contact surface that can contact a part of the ventral end surface of another shroud located on the circumferential dorsal side of the shroud. The ventral end surface has a ventral contact surface that can contact a part of the dorsal end surface of another shroud located on the circumferential ventral side of the shroud. At least one of the counter gas path surface and the gas path surface in a region including the ventral contact surface in an outer edge side region of the shroud body spaced apart from the blade body in the spreading direction is machined so that the width in the radial direction of the ventral contact surface is smaller than the width in the radial direction of the dorsal contact surface.

Advantages of the Invention

[0018] According to the moving blade and the method for machining the moving blade of the present disclosure, problems caused by creep deformation can be suppressed.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Mode for Carrying Out the Invention

[0020] Hereinafter, embodiments and various modifications of the present disclosure will be described in detail with reference to the drawings.

[0021] "Embodiment of Gas Turbine" An embodiment of a gas turbine according to the present disclosure will be described with reference to FIG. 1.

[0022] The gas turbine 10 of the present embodiment includes a compressor 20 that compresses air A, a combustor 30 that burns fuel F in the compressed air A by the compressor 20 to generate combustion gas G, and a turbine 40 that is driven by the combustion gas G.

[0023] 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 blade 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 blade rows 46. Hereinafter, the direction in which the axis Ar extends is defined as the axial direction Da, the circumferential direction centered on this axis Ar is simply defined as the circumferential direction Dc, and the direction perpendicular to the axis Ar is defined as the radial direction Dr. Also, one side in the axial direction Da is defined as the upstream side Dau of the axis, and the opposite side is defined as the downstream side Dad of the axis. Further, the side approaching the axis Ar in the radial direction Dr is defined as the inner side Dri in the radial direction, and the opposite side is defined as the outer side Dro in the radial direction.

[0024] The compressor 20 is disposed on the upstream side Dau of the axis with respect to the turbine 40. The compressor rotor 21 and the turbine rotor 41 are located on the same axis Ar and are connected to each other to form a gas turbine rotor 11. For example, a rotor of a generator GEN is connected to this gas turbine rotor 11. The gas turbine 10 further includes an intermediate casing 14 disposed between the compressor casing 25 and the turbine casing 45. The combustor 30 is attached to this intermediate casing 14. The compressor casing 25, the intermediate casing 14, and the turbine casing 45 are connected to each other to form a gas turbine casing 15.

[0025] The compressor rotor 21 has a rotor shaft 22 extending in the axial direction Da about the axis Ar, and a plurality of moving blade rows 23 attached to the rotor shaft 22. The plurality of moving blade rows 23 are arranged in the axial direction Da. Each moving blade row 23 is composed of a plurality of moving blades arranged in the circumferential direction Dc. On the downstream side Dad in the axial direction of each of the plurality of moving blade rows 23, one of the plurality of stationary blade rows 26 is arranged. Each stationary blade row 26 is provided inside the compressor casing 25. Each stationary blade row 26 is composed of a plurality of stationary blades arranged in the circumferential direction Dc.

[0026] The turbine rotor 41 has a rotor shaft 42 extending in the axial direction Da about the axis Ar, and a plurality of moving blade rows 43 attached to the rotor shaft 42. The plurality of moving blade rows 43 are arranged in the axial direction Da. Each moving blade row 43 is composed of a plurality of moving blades 50 arranged in the circumferential direction Dc. The moving blades 50 are attached to the rotor shaft 22. On the upstream side Dau in the axial direction of each of the plurality of moving blade rows 43, one of the plurality of stationary blade rows 46 is arranged. Each stationary blade row 46 is provided inside the turbine casing 45. Each stationary blade row 46 is composed of a plurality of stationary blades arranged in the circumferential direction Dc.

[0027] The compressor 20 sucks in air A and compresses it. The compressed air, that is, the compressed air, flows into the combustor 30 through the intermediate casing 14. Fuel F is supplied to the combustor 30 from the outside. The combustor 30 burns the fuel F in the compressed air to generate combustion gas G. This combustion gas G flows into the turbine casing 45 and rotates the turbine rotor 41. Due to the rotation of this turbine rotor 41, the generator GEN generates electricity.

[0028] Hereinafter, various embodiments of the moving blades 50 of the turbine 40 described above will be described.

[0029] "First Embodiment of Moving Blade" With reference to FIGS. 2 to 10, the moving blade 50 according to the first embodiment of the present invention will be described.

[0030] As shown in Fig. 2, the moving blade 50 of this embodiment includes a blade body 51, a platform 52, a blade root 53, and a shroud 60.

[0031] The blade body 51 extends in the radial direction Dr. The cross-section of the blade body 51 perpendicular to the radial direction Dr forms an airfoil shape. As shown in Fig. 3, the blade body 51 has a leading edge 54, a trailing edge 55, a ventral surface 56 which is a concave surface, and a dorsal surface 57 which is a convex surface. The leading edge 54 is the outer edge of the blade body 51 on the most upstream side Dau in the axial direction Da among the upstream side Dau and the downstream side Dad in the axial direction Da. The trailing edge 55 is the outer edge of the blade body 51 on the most downstream side Dad in the axial direction Da among the upstream side Dau and the downstream side Dad in the axial direction Da. The leading edge 54 and the trailing edge 55 are present at the connecting portion between the ventral surface 56 and the dorsal surface 57. Both the leading edge 54 and the trailing edge 55 extend in the radial direction Dr. The ventral surface 56 and the dorsal surface 57 are in a back-to-back relationship with each other.

[0032] Hereinafter, the side where the dorsal surface 57 exists with respect to the ventral surface 56 in the circumferential direction Dc is defined as the circumferential dorsal side Dc1, and the other side, where the ventral surface 56 exists with respect to the dorsal surface 57 in the circumferential direction Dc, is defined as the circumferential ventral side Dc2.

[0033] As shown in Fig. 2, the platform 52 is provided at the end of the blade body 51 on the inner side Dri in the radial direction. The platform 52 extends in a direction having a direction component perpendicular to the radial direction Dr. The blade root 53 is provided on the inner side Dri in the radial direction of the platform 52. The blade root 53 is a structure for attaching the moving blade 50 to the rotor shaft 42 (see Fig. 1).

[0034] The shroud 60 is provided at the radially outer end Dro of the blade body 51. A honeycomb material 47 is installed at a position radially outer Dro than the shroud 60. The honeycomb material 47 is fixed to the inner circumference of the turbine casing 45. The honeycomb material 47 suppresses leakage of the combustion gas G between the turbine casing 45 and the moving blade 50. Further, as shown in FIG. 3, the shroud 60 has a shroud body 61, a seal fin 66, and a protrusion 73.

[0035] The shroud body 61 extends in a spreading direction Dt away from the blade body 51. This spreading direction Dt is a direction having a component perpendicular to the radial direction Dr in which the blade body 51 extends, and is a direction on the side away from the blade body 51.

[0036] The shroud body 61 has a blade connection region 62 and an outer edge side region 63. The blade connection region 62 is a region including the region to which the blade body 51 is connected. The outer edge of the blade connection region 62 surrounds the blade body 51 from the outside in the radial direction Dr view. A plurality of air holes 90 are formed in the blade connection region 62 at positions overlapping the blade body 51 in the radial direction Dr. The plurality of air holes 90 are formed at intervals along the blade body 51 in the radial direction Dr view. The air holes 90 communicate with a cooling flow path (not shown) extending in the radial direction Dr inside the blade body 51. Cooling air flows toward the radially outer side Dro in this flow path inside the blade body 51. The shroud 60 is cooled by the cooling air being discharged to the outside from the air holes 90.

[0037] The outer edge side region 63 is connected to the blade connection region 62 and is formed outside the blade connection region 62 in the spreading direction Dt. The outer edge side region 63 is a region of the shroud body 61 excluding the blade connection region 62. The outer edge side region 63 is provided so as to surround the blade connection region 62 from the outside in the radial direction Dr view.

[0038] Also, as shown in FIG. 4, both the wing-body connection region 62 and the outer edge side region 63 have an anti-gas path surface 64 and a gas path surface 65. The anti-gas path surface 64 is a surface facing the radially outer side Dro with respect to the axis Ar, and the gas path surface 65 is a surface facing the radially inner side Dri with respect to the axis Ar.

[0039] A seal fin 66 protruding in the radially outer side Dro is formed on the anti-gas path surface 64. As shown in FIG. 3, the seal fin 66 is formed so as to extend in the circumferential direction Dc. The seal fin 66 faces the honeycomb material 47 (see FIG. 2) installed on the inner circumference of the turbine casing 45 in the radial direction Dr. In the present embodiment, the seal fins 66 are respectively formed on the upstream side Dau and the downstream side Dad of the axis of the shroud body 61. The seal fin 66 on the upstream side Dau of the axis is provided further upstream of the axis Dau than the air hole 90 on the most upstream side Dau among the plurality of air holes 90. The seal fin 66 on the downstream side Dad of the axis is provided further downstream of the axis Dad than the air hole 90 on the most downstream side Dad among the plurality of air holes 90.

[0040] Also, the gas path surface 65 has a fillet surface 67. The fillet surface 67 is a surface that extends so as to be gradually located on the radially outer side Dro as it extends in the spreading direction Dt from each of the ventral surface 56 and the dorsal surface 57 of the wing body 51. The fillet surface 67 is formed so as to surround the wing body 51 from the outside in the radial direction Dr view. In the present embodiment, the outer edge of the wing-body connection region 62 in the spreading direction Dt coincides with a fillet edge 67a which is the outer edge of the fillet surface 67 in the spreading direction Dt.

[0041] Also, the outer edge side region 63 has an end surface 68 that connects the edge of the anti-gas path surface 64 of the outer edge side region 63 and the edge of the gas path surface 65 of the outer edge side region 63. The end surface 68 has a front end surface 69, a rear end surface 70, a dorsal end surface 71, and a ventral end surface 72.

[0042] The front end face 69 is the face among the end faces 68 that faces the upstream side Dau of the axis. The front end face 69 has a first front end face 69a and a second front end face 69b.

[0043] The first front end face 69a is the face among the front end faces 69 that is located on the upstream side Dau of the axis with respect to the leading edge 54 of the airfoil 51. The first front end face 69a extends in the circumferential direction Dc in a direction perpendicular to the axis Ar. The first front end face 69a extends linearly in the circumferential direction Dc. In the present embodiment, the first front end face 69a constitutes the region of the circumferential ventral side Dc2 among the front end faces 69. The end on the circumferential dorsal side Dc1 of the first front end face 69a is at the same circumferential Dc position as the most circumferential dorsal side Dc1 of the fillet edge 67a. Also, in the region on the upstream side Dau of the axis that is further upstream of the seal fin 66 on the upstream side Dau of the shroud body 61 and includes the first front end face 69a, there are provided protruding portions 73 that protrude toward the radially outer side Dro. Two protruding portions 73 are provided side by side in the circumferential direction Dc. These two protruding portions 73 are located on the circumferential ventral side Dc2 with respect to the center of the circumferential direction Dc on the front end face 69.

[0044] The second front end face 69b is a face that is inclined with respect to the first front end face 69a such that it gradually faces the downstream side Dad of the axis as it moves away from the airfoil 51 in the circumferential direction Dc. In the present embodiment, the second front end face 69b is the face located on the circumferential dorsal side Dc1 with respect to the first front end face 69a. The second front end face 69b extends further toward the circumferential dorsal side Dc1 from the end on the circumferential dorsal side Dc1 of the first front end face 69a. The second front end face 69b is a face that is linearly inclined with respect to the first front end face 69a such that it gradually faces the downstream side Dad of the axis as it moves toward the circumferential dorsal side Dc1.

[0045] The rear end face 70 is the face among the end faces 68 that faces the downstream side Dad of the axis. The rear end face 70 extends linearly in the circumferential direction Dc in a radial Dr view.

[0046] The dorsal end face 71 is a face that faces the circumferential dorsal side Dc1 where the dorsal face 57 exists with respect to the ventral face 56 in the circumferential direction Dc among the end faces 68 and is located on the circumferential dorsal side Dc1 with respect to the wing body 51. The dorsal end face 71 connects the end on the circumferential dorsal side Dc1 of the front end face 69 and the end on the circumferential dorsal side Dc1 of the rear end face 70. In the radial direction Dr view, the dorsal end face 71 extends in a zigzag shape in the axial direction Da. The dorsal end face 71 has a first dorsal end face 71a, a curved dorsal end face 71b, a second dorsal end face 71c, and a third dorsal end face 71d. The first dorsal end face 71a, the curved dorsal end face 71b, the second dorsal end face 71c, and the third dorsal end face 71d are arranged in this order from the upstream side Dau of the axis to the downstream side Dad of the axis.

[0047] The first dorsal end face 71a extends from the end on the circumferential dorsal side Dc1 of the front end face 69 to the downstream side Dad of the axis. The first dorsal end face 71a is inclined with respect to the front end face 69 so as to gradually face the circumferential ventral side Dc2 as it goes toward the downstream side Dad of the axis.

[0048] The curved dorsal end face 71b is provided at the end on the downstream side Dad of the axis of the first dorsal end face 71a. In the radial direction Dr view, the curved dorsal end face 71b is curved in an arc shape so as to be recessed toward the circumferential ventral side Dc2. The curved dorsal end face 71b smoothly connects the first dorsal end face 71a and the second dorsal end face 71c.

[0049] The second dorsal end face 71c extends from the curved dorsal end face 71b to the downstream side Dad of the axis. The second dorsal end face 71c is inclined with respect to the first dorsal end face 71a so as to gradually face the circumferential dorsal side Dc1 as it goes toward the downstream side Dad of the axis.

[0050] The third dorsal end face 71d extends from the end on the downstream side Dad of the axis of the second dorsal end face 71c to the downstream side Dad of the axis. The third dorsal end face 71d is inclined with respect to the second dorsal end face 71c so as to gradually face the circumferential ventral side Dc2 as it goes toward the downstream side Dad of the axis. The end on the downstream side Dad of the third dorsal end face 71d is connected to the end on the circumferential dorsal side Dc1 of the rear end face 70.

[0051] The ventral end face 72 is a face that faces the circumferential ventral Dc2 where the ventral face 56 exists with respect to the dorsal face 57 in the circumferential direction Dc among the end faces 68 and is located on the circumferential ventral Dc2 side of the wing body 51. The ventral end face 72 connects the end on the circumferential ventral Dc2 side of the front end face 69 and the end on the circumferential ventral Dc2 side of the rear end face 70. The ventral end face 72 extends in a zigzag shape in the axial direction Da in the view of the radial direction Dr. The ventral end face 72 has a first ventral end face 72a, a second ventral end face 72b, a curved ventral end face 72c, and a third ventral end face 72d. The first ventral end face 72a, the second ventral end face 72b, the curved ventral end face 72c, and the third ventral end face 72d are arranged in this order from the axial upstream side Dau to the axial downstream side Dad.

[0052] The first ventral end face 72a extends from the end on the circumferential ventral Dc2 side of the front end face 69 to the axial downstream side Dad. The first ventral end face 72a is inclined with respect to the front end face 69 so as to gradually face the circumferential ventral Dc2 as it goes toward the axial downstream side Dad.

[0053] The second ventral end face 72b extends from the end on the axial downstream side Dad of the first ventral end face 72a to the axial downstream side Dad. The second ventral end face 72b is inclined with respect to the first ventral end face 72a so as to gradually face the circumferential dorsal Dc1 as it goes toward the axial downstream side Dad. The connection part between the first ventral end face 72a and the second ventral end face 72b is at a position overlapping with the curved dorsal end face 71b in the circumferential direction Dc.

[0054] The curved ventral end face 72c is provided at the end on the axial downstream side Dad of the second dorsal end face 71c. The curved ventral end face 72c is curved in an arc shape so as to be recessed in the circumferential dorsal Dc1 in the view of the radial direction Dr. The curved ventral end face 72c smoothly connects the second ventral end face 72b and the third ventral end face 72d. The curved ventral end face 72c is at a position overlapping with the connection part between the second dorsal end face 71c and the third dorsal end face 71d in the circumferential direction Dc.

[0055] The third ventral end face 72d extends from the curved ventral end face 72c to the downstream side Dad of the axis. The third ventral end face 72d is inclined with respect to the second ventral end face 72b so as to gradually face the circumferential ventral side Dc2 as it goes toward the downstream side Dad of the axis. The end of the third ventral end face 72d on the downstream side Dad of the axis is connected to the end of the rear end face 70 on the circumferential ventral side Dc2.

[0056] Here, for the anti-gas path surface 64 and the gas path surface 65, the ratio of the position change amount in the radial direction Dr per unit position change amount in the spreading direction Dt is defined as the surface change rate. As shown in FIG. 5, the gas path surface 65 in the wing body connection region 62 is a curved surface in which this surface change rate gradually decreases as it goes toward the spreading direction Dt.

[0057] In addition, the outer edge side region 63 has a specific outer edge side region 74. Here, the interval between the gas path surface 65 and the anti-gas path surface 64 per unit position change amount in the spreading direction Dt is defined as the thickness t of the shroud body 61, and the change amount of this thickness t is defined as the thickness change rate. The average thickness change rate in the specific outer edge side region 74 is larger than the thickness change rate at the region edge 62a in the wing body connection region 62 that is in contact with the specific outer edge side region 74. The specific outer edge side region 74 is a region having this feature.

[0058] In the present embodiment, the specific outer edge side region 74 is provided on both sides in the circumferential direction Dc with respect to the wing body 51. Further, the region edge 62a in the wing body connection region 62 that is in contact with the specific outer edge side region 74 in the spreading direction Dt is on the fillet edge 67a that is the outer edge of the fillet surface 67 in the spreading direction Dt.

[0059] In addition, the specific outer edge side region 74 has a first outer edge side region 75 and a second outer edge side region 76.

[0060] The average surface change rate on the gas path surface 65 of the first outer edge side region 75 is larger than the average surface change rate on the anti-gas path surface 64 of the first outer edge side region 75. The first outer edge side region 75 is a region having this feature.

[0061] In this embodiment, the first outer edge side region 75 is a region on the upstream side Dau of the axis in the shroud body 61, and is a region of the circumferential dorsal side Dc1 where the dorsal surface 57 exists with respect to the ventral surface 56 in the circumferential direction Dc. The first outer edge side region 75 is located on the upstream side Dau of the axis from the curved dorsal end face 71b. The first outer edge side region 75 extends in the circumferential dorsal side Dc1 from the fillet edge 67a (the outer edge of the wing body connection region 62) to the dorsal end face 71. Further, the first outer edge side region 75 extends downstream in the axis direction Da from the front end face 69.

[0062] A first recess 78 is formed in the gas path surface 65 of the first outer edge side region 75. As shown in FIG. 5, the inner surface of the first recess 78 is curved so as to be gradually located on the radially outer side Dro as it moves away from the wing body 51. Due to this first recess 78, the average surface change rate on the gas path surface 65 of the first outer edge side region 75 is larger than the average surface change rate on the anti-gas path surface 64 of the first outer edge side region 75. The first recess 78 extends from the upstream end Dau of the axis of the first outer edge side region 75 to the downstream end Dad of the axis. From another perspective, the width of the first outer edge side region 75 in the axis direction Da is defined by the first recess 78. The first recess 78 is located on the upstream side Dau of the axis from the curved dorsal end face 71b. Further, the first recess 78 is formed so as to extend in the circumferential ventral side Dc2 from the connection portion between the front end face 69 and the dorsal end face 71. The first recess 78 is formed in a triangular shape so as to expand in the axis direction Da as it goes toward the circumferential ventral side Dc2 in the radial direction Dr view. The outer edge of the upstream end Dau of the first recess 78 is on the second front end face 69b, and the outer edge of the downstream end Dad of the first recess 78 is on the first dorsal end face 71a. Further, the outer edge of the circumferential ventral side Dc2 of the first recess 78 linearly extends downstream in the axis direction Dad from the end of the circumferential ventral side Dc2 of the second front end face 69b in the radial direction Dr view. A part of the outer edge of the circumferential ventral side Dc2 of the first recess 78 is on the fillet edge 67a.

[0063] The average surface change rate on the anti-gas path surface 64 of the second outer edge side region 76 is larger than the average surface change rate on the gas path surface 65 of the second outer edge side region 76. The second outer edge side region 76 is a region having this characteristic.

[0064] In the present embodiment, the second outer edge side region 76 is a region on the upstream side Dau of the axis in the shroud main body 61, and is a region of the circumferential ventral side Dc2 where the ventral surface 56 exists with respect to the dorsal surface 57 in the circumferential direction Dc. The second outer edge side region 76 is located on the upstream side Dau of the axis rather than the second ventral end surface 72b, and extends in the circumferential ventral side Dc2 from the fillet edge 67a (the outer edge of the airfoil connection region 62) to the ventral end surface 72. Further, the second outer edge side region 76 extends from the region on the downstream side Dad of the axis rather than the seal fin 66 on the upstream side Dau of the axis to the downstream side Dad of the axis.

[0065] A second recess 79 is formed in the anti-gas path surface 64 of the second outer edge side region 76. As shown in FIG. 5, the inner surface of the second recess 79 is curved so as to be gradually located on the radially inner side Dri as it moves away from the airfoil 51. Due to this second recess 79, the average surface change rate on the anti-gas path surface 64 of the second outer edge side region 76 is larger than the average surface change rate on the gas path surface 65 of the second outer edge side region 76. The second recess 79 extends from the end on the upstream side Dau of the axis of the second outer edge side region 76 to the end on the downstream side Dad of the axis. From another viewpoint, the width of the second outer edge side region 76 in the axial direction Da is defined by the second recess 79. The second recess 79 is on the upstream side Dau of the axis rather than the second ventral end surface 72b and is located on the downstream side Dad of the axis rather than the front end surface 69. Further, the second recess 79 is located on the circumferential ventral side Dc2 rather than the fillet edge 67a of the circumferential dorsal side Dc1 at the same position in the axial direction Da. The second recess 79 is formed in a parallelogram shape that extends in the axial direction Da in the view of the radial direction Dr and is located on the circumferential ventral side Dc2 as it goes toward the downstream side Dad of the axis. The second recess 79 is formed along the first ventral end surface 72a. The outer edge of the circumferential ventral side Dc2 of the second recess 79 is on the first ventral end surface 72a.

[0066] Further, in the intermediate portion of the axis direction Da in the wing-body connection region 62 of the anti-gas path surface 64, an air introduction recess 91 communicating with some of the plurality of air holes 90 described above is formed. The air introduction recess 91 opens toward the radially outer side Dro. The air introduction recess 91 is closed by a lid portion 92.

[0067] Furthermore, inside the shroud main body 61, a plurality of cooling channels 93 extending in the spreading direction Dt from the air introduction recess 91 in the wing-body connection region 62 and allowing cooling air to flow are formed. The cooling channels 93 communicate with the air holes 90 via the air introduction recess 91. Cooling air that has passed through the air holes 90 flows in the spreading direction Dt through the cooling channels 93. Thereby, the shroud 60 is cooled from the inside.

[0068] The cooling channels 93 include a first cooling channel 93a, a second cooling channel 93b, and a third cooling channel 93c. The first cooling channel 93a extends from the air introduction recess 91 to the circumferentially dorsal side Dc1 and is linearly formed in a radially Dr view so as to be gradually positioned on the axially upstream side Dau as it goes toward the circumferentially dorsal side Dc1. The first cooling channel 93a extends from the air introduction recess 91 to the first dorsal end surface 71a. As shown in FIG. 6, the first cooling channel 93a extends along the anti-gas path surface 64. Also, the first cooling channel 93a is located radially outside Dro of the first recess 78 in the first outer edge side region 75. Note that the number of the first cooling channels 93a can be appropriately changed.

[0069] The second cooling flow path 93b extends from the air introduction recess 91 to the circumferential ventral side Dc2 and is linearly formed in a radial direction Dr view so as to be gradually located on the upstream side Dau of the axis as it goes toward the circumferential dorsal side Dc1. The second cooling flow path 93b extends in a direction from the air introduction recess 91 toward the first dorsal end face 71a. A plurality of the second cooling flow paths 93b are formed side by side in the axial direction Da. In the illustrated example, among the second cooling flow paths 93b, some of the second cooling flow paths 93b (intermediate second cooling flow paths 93b), excluding the second cooling flow paths 93b on the most upstream side Dau and the most downstream side Dad of the axis, are formed to communicate with the second recess 79 as shown in FIG. 7. Thereby, these intermediate second cooling flow paths 93b open in the spreading direction Dt at the anti-gas path surface 64 in the second outer edge side region 76. Further, the second cooling flow path 93b approaches the anti-gas path surface 64 as it goes toward the circumferential ventral side Dc2. The end portion on the circumferential ventral side Dc2 of the second cooling flow path 93b is located near the outer edge of the circumferential dorsal side Dc1 of the second recess 79 within the second recess 79. Note that the number of the second cooling flow paths 93b can be changed as appropriate.

[0070] The third cooling flow path 93c extends from the air introduction recess 91 to the circumferential dorsal side Dc1 and is linearly formed in a radial direction Dr view so as to be gradually located on the downstream side Dad of the axis as it goes toward the circumferential dorsal side Dc1. The third cooling flow path 93c extends from the air introduction recess 91 to the third dorsal end face 71d. A plurality of the third cooling flow paths 93c are formed side by side in the axial direction Da. Note that the number of the third cooling flow paths 93c can be changed as appropriate.

[0071] Incidentally, as shown in FIG. 3, a plurality of shrouds 60 are arranged annularly in the circumferential direction Dc. The shrouds 60 adjacent to each other in the circumferential direction Dc are connected. For this reason, the back end face 71 and the front end face 72 of the shroud 60 each have a contact surface 80 for connecting the shrouds 60 adjacent to each other in the circumferential direction Dc. Hereinafter, the contact surface 80 of the back end face 71 is referred to as a back contact surface 81, and the contact surface 80 of the front end face 72 is referred to as a front contact surface 82. The back contact surface 81 and the front contact surface 82 are formed at positions in the same axial direction Da.

[0072] The back contact surface 81 is capable of contacting a part (front contact surface 82) of the front end face 72 of another shroud 60 located on the circumferential back side Dc1 of the shroud 60. The back contact surface 81 is a region including the connection portion between the second back end face 71c and the third back end face 71d of the back end face 71, and is formed from the second back end face 71c to the third back end face 71d. The back contact surface 81 is on the downstream side Dad of the curved back end face 71b in the axial direction and on the upstream side Dau of the rear end face 70 in the axial direction.

[0073] The front contact surface 82 is capable of contacting a part (back contact surface 81) of the back end face 71 of another shroud 60 located on the circumferential front side Dc2 of the shroud 60. The front contact surface 82 is a region including the curved front end face 72c of the front end face 72, and is formed from the second front end face 72b to the third front end face 72d. The front contact surface 82 is on the downstream side Dad of the first front end face 72a in the axial direction and on the upstream side Dau of the rear end face 70 in the axial direction.

[0074] As shown in FIG. 8, in the present embodiment, a third recess 83 is formed at the position of the ventral contact surface 82 in the shroud body 61. The third recess 83 is located on the circumferential dorsal side Dc1 with respect to the airfoil 51. Further, the third recess 83 is located on the downstream side Dad of the axial line with respect to the first ventral end surface 72a and on the upstream side Dau of the axial line with respect to the rear end surface 70. The third recess 83 is formed in a U shape in the radial direction Dr view so as to follow the contact surface 80. Due to this third recess 83, the anti-gas path surface 64 in the region where the ventral contact surface 82 is located is located on the radially inner side Dri with respect to the anti-gas path surface 64 in the region where the dorsal contact surface 81 is located. As a result, the width in the radial direction Dr of the ventral contact surface 82 is smaller than the width in the radial direction Dr of the dorsal contact surface 81.

[0075] (Method for manufacturing a moving blade) Subsequently, with reference to the flow of FIG. 9, a method for manufacturing the above-described moving blade 50 will be described. As shown in FIG. 9, the method for manufacturing a moving blade according to the present embodiment includes a casting step S1 and a finishing step S2. First, the casting step S1 is performed. In the casting step S1, the raw material of the moving blade 50 is poured into a mold to form an intermediate product of the moving blade 50. In the casting step S1, the detailed shapes of the shroud 60 such as the first recess 78, the second recess 79, the second front end surface 69b, and the third recess 83 are integrally formed by casting. After the casting step S1, the finishing step S2 is performed. In the finishing step S2, for example, the following finishing treatment is performed on the intermediate product of the moving blade 50.

[0076] In the finishing step S2, for example, a cooling flow path 93 is machined and formed in the intermediate product of the moving blade 50. Then, the lid portion 92 is attached. Also, in the finishing step S2, a heat insulating coating is applied as necessary. The above-described moving blade 50 can be obtained by the above-described manufacturing method, but the above-described moving blade 50 can also be obtained by processing an existing moving blade.

[0077] (Method for processing a moving blade) Hereinafter, with reference to the flow of FIG. 10, a method for machining a moving blade will be described. The method for machining the moving blade of the present embodiment is a machining method for machining an existing moving blade to obtain the moving blade 50 described above. The existing moving blade used here has first to fourth cutting portions 95, 96, 97, 98, etc. shown in FIGS. 5 to 8 in addition to the configuration of the moving blade 50 described above.

[0078] As shown in FIG. 10, the method for machining the moving blade of the present embodiment includes a first cutting step S21, a second cutting step S22, a third cutting step S23, and a finishing step S2a. First, the first cutting step S21 is performed. In the first cutting step S21, at least one of the anti-gas path surface 64 and the gas path surface 65 in the specific outer edge side region 74 in the outer edge side region 63 of the existing moving blade is cut so that the average thickness change rate in the specific outer edge side region 74 in the outer edge side region 63 is greater than the thickness change rate at the region edge 62a in the blade body connection region 62 that is in contact with the specific outer edge side region 74. In the first cutting step S21 in the present embodiment, as shown in FIG. 5, the first cutting portion 95 on the gas path surface 65 is cut off to form the first concave portion 78, and the second cutting portion 96 on the anti-gas path surface 64 is cut off to form the second concave portion 79. The formation of the first concave portion 78 forms the first outer edge side region 75, and the formation of the second concave portion 79 forms the second outer edge side region 76.

[0079] After the first cutting step S21, the second cutting step S22 is performed. In the second cutting step S22, the front end surface 69 of the existing moving blade is cut so that the second front end surface 69b becomes a surface inclined with respect to the first front end surface 69a so as to gradually face the downstream side Dad of the axis as it moves away from the blade body 51 in the circumferential direction Dc. In the second cutting step S22 in the present embodiment, as shown in FIG. 3, the third cutting portion 97 on the front end surface 69 is cut off to form the second front end surface 69b.

[0080] After the second cutting step S22, a third cutting step S23 is performed. In the third cutting step S23, at least one of the anti-gas path surface 64 and the gas path surface 65 in the region including the ventral contact surface 82 in the outer edge region 63 spaced apart from the blade body 51 in the spreading direction Dt in the shroud body 61 of the existing moving blade is cut so that the width in the radial direction Dr of the ventral contact surface 82 is smaller than the width in the radial direction Dr of the dorsal contact surface 81. In the third cutting step S23 in the present embodiment, as shown in FIG. 8, the fourth cutting portion 98 on the anti-gas path surface 64 is cut off to form the third recess 83.

[0081] After the third cutting step S23, a finishing step S2a is performed. In the finishing step S2a, finishing processing is performed in the same manner as the above-described finishing step S2. In the finishing step S2a, for example, if there is a clogging in the cooling flow path 93, the clogging is removed. Also, in the finishing step S2, a heat insulating coating is applied as necessary.

[0082] Through the above procedure, the machining of the moving blade is completed, and the moving blade 50 of the present embodiment described above can be obtained. Note that the order of the first cutting step S21, the second cutting step S22, and the third cutting step S23 can be appropriately changed. Also, the first cutting step S21, the second cutting step S22, and the third cutting step S23 may be performed at the same timing as other cutting steps.

[0083] Subsequently, the operation and effect of the moving blade 50 described above will be described. In the present embodiment, the average thickness change rate in the specific outer edge region 74 in the outer edge region 63 is larger than the thickness change rate at the region edge 62a in the blade body connection region 62 that is in contact with the specific outer edge region 74.

[0084] The outer edge side region 63 has a lower rigidity compared to the wing-body connection region 62, and is prone to creep deformation due to centrifugal force. In the present embodiment, the gas path surface 65 of the wing-body connection region 62 is a curved surface where the surface change rate, which is the ratio of the position change amount in the radial direction Dr per unit position change amount in the spreading direction Dt, gradually decreases as it goes in the spreading direction Dt. Further, the average thickness change rate in the specific outer edge side region 74 in the outer edge side region 63 is larger than the thickness change rate in the region edge 62a in the wing-body connection region 62 that is in contact with the specific outer edge side region 74. Therefore, while smoothly connecting the outer edge side region 63 and the wing-body connection region 62, the outer edge side region 63 becomes thinner than the wing-body connection region 62. Thereby, while maintaining the aerodynamic characteristics, the outer edge side region 63 can be lightened. Thus, the centrifugal force applied to the outer edge side region 63 of the shroud 60 can be reduced, and the creep deformation that turns up in the radially outer side Dro can be suppressed. Therefore, problems due to creep deformation can be suppressed.

[0085] In the present embodiment, the specific outer edge side region 74 has a first outer edge side region 75. The average surface change rate on the gas path surface 65 of the first outer edge side region 75 is larger than the average surface change rate on the anti-gas path surface 64 of the first outer edge side region 75.

[0086] Structures such as seal fins 66 are formed on the anti-gas path surface 64 to prevent leakage of the working fluid (combustion gas G). For this reason, if the shape of the anti-gas path surface 64 is changed, it is necessary to redesign the shape and arrangement of structures such as the seal fins 66, which may lead to performance degradation. Therefore, changing the shape of the anti-gas path surface 64 is considered unfavorable. In the present embodiment, at the time of design, only the shape of the gas path surface 65 is changed in the first outer edge side region 75 without changing the shape of the anti-gas path surface 64, so that the outer edge side region 63 can be made thinner than the wing-body connection region 62 and the outer edge side region 63 can be lightened.

[0087] In the present embodiment, the first outer edge side region 75 is a region on the upstream side Dau of the shroud body 61 in the axial direction, and is a region of the circumferential dorsal side Dc1 where the dorsal surface 57 exists with respect to the ventral surface 56 in the circumferential direction Dc centered on the axis Ar.

[0088] In the present embodiment, at the time of design, only the shape of the gas path surface 65 is changed without changing the shape of the anti-gas path surface 64 in the upstream side Dau in the axial direction and the circumferential dorsal side Dc1 of the shroud 60, so that the outer edge side region 63 can be made thinner than the wing body connection region 62, and the outer edge side region 63 can be lightened.

[0089] In the present embodiment, the specific outer edge side region 74 has a second outer edge side region 76. The average surface change rate of the anti-gas path surface 64 of the second outer edge side region 76 is larger than the average surface change rate of the gas path surface 65 of the second outer edge side region 76.

[0090] The gas path surface 65 through which the working fluid flows is preferably formed in a smooth shape with few irregularities in terms of aerodynamic characteristics. In the present embodiment, at the time of design, only the shape of the anti-gas path surface 64 is changed without changing the shape of the gas path surface in the second outer edge side region 76, so that the outer edge side region 63 can be made thinner than the wing body connection region 62, and the outer edge side region 63 can be lightened.

[0091] In the present embodiment, the second outer edge side region 76 is a region on the upstream side Dau of the shroud body 61 in the axial direction, and is a region of the circumferential ventral side Dc2 where the ventral surface 56 exists with respect to the dorsal surface 57 in the circumferential direction Dc centered on the axis Ar.

[0092] In the present embodiment, at the time of design, only the shape of the anti-gas path surface 64 is changed without changing the shape of the gas path surface 65 in the upstream side Dau in the axial direction and the circumferential ventral side Dc2 of the shroud 60, so that the outer edge side region 63 can be made thinner than the wing body connection region 62, and the outer edge side region 63 can be lightened.

[0093] In the present embodiment, a cooling flow path 93 that extends in the spreading direction Dt from the wing body connection region 62 and allows cooling air to flow is formed inside the shroud main body 61. The cooling flow path 93 opens in the spreading direction Dt at the anti-gas path surface 64 in the second outer edge side region 76.

[0094] If the cooling flow path 93 opens to the gas path surface 65 side and the inner surface of the cooling flow path 93 is exposed, the exposed inner surface of the cooling flow path 93 becomes a step of the gas path surface 65, and the aerodynamic characteristics deteriorate. In the present embodiment, by opening the cooling flow path 93 to the anti-gas path surface 64 side, it is possible to suppress the exposure of the inner surface of the cooling flow path 93 to the gas path surface 65 side during design, and it is possible to suppress the deterioration of the aerodynamic characteristics.

[0095] In the present embodiment, the gas path surface 65 has a fillet surface 67 that extends so as to be gradually positioned radially outward Dro in the spreading direction Dt from each of the ventral surface 56 and the dorsal surface 57 of the wing body 51. The region edge 62a of the wing body connection region 62 in the spreading direction Dt is on the fillet edge 67a that is the outer edge of the fillet surface 67 in the spreading direction Dt.

[0096] In the region of the shroud main body 61 that is outside the fillet surface 67 in the spreading direction Dt, creep deformation due to centrifugal force is more likely to occur than in the region where the fillet surface 67 is formed. In the present embodiment, a specific outer region can be formed to extend in the spreading direction Dt from the fillet edge 67a. Therefore, only the region outside the fillet surface 67 in the spreading direction Dt where creep deformation is likely to occur can be lightened, and the amount of creep deformation can be reduced.

[0097] In the present embodiment, the front end surface 69 has a first front end surface 69a and a second front end surface 69b. The first front end surface 69a is located on the upstream side Dau of the axis from the leading edge 54 and extends in the circumferential direction Dc centered on the axis Ar and in a direction perpendicular to the axis Ar. The second front end surface 69b is a surface inclined with respect to the first front end surface 69a so as to gradually go toward the downstream side Dad of the axis as it goes toward the side away from the wing body 51 in the circumferential direction Dc.

[0098] In this embodiment, a second front end face 69b that is inclined with respect to the first front end face 69a is formed at the end of the shroud 60 on the upstream side Dau of the axis. For this reason, compared with the case where the front end face 69 extends in a straight line in a direction perpendicular to the axis Ar in a radial direction Dr view, the volume of the shroud 60 can be reduced, and the end of the shroud 60 on the upstream side Dau of the axis can be lightened. Thereby, the centrifugal force applied to the shroud 60 can be reduced, and the creep deformation that turns up toward the outer side Dro in the radial direction of the shroud 60 can be suppressed. Therefore, problems due to creep deformation can be suppressed.

[0099] In this embodiment, the second front end face 69b is a face that is located in the circumferential dorsal side Dc1 where the dorsal side face 57 exists with respect to the ventral side face 56 in the circumferential direction Dc with respect to the first front end face 69a. Further, the second front end face 69b is a face inclined with respect to the first front end face 69a so as to gradually face the downstream side Dad of the axis as it goes toward the circumferential dorsal side Dc1.

[0100] In this embodiment, a second front end face 69b that is inclined with respect to the first front end face 69a is formed at the end of the shroud 60 on the upstream side Dau of the axis and in the circumferential dorsal side Dc1. For this reason, the end of the shroud 60 on the upstream side Dau of the axis and in the circumferential dorsal side Dc1 can be lightened.

[0101] In this embodiment, the dorsal end face 71 has a dorsal contact face 81 that can contact a part of the ventral end face 72 of another shroud 60 located in the circumferential dorsal side Dc1 of the shroud 60. The ventral end face 72 has a ventral contact face 82 that can contact a part of the dorsal end face 71 of another shroud 60 located in the circumferential ventral side Dc2 of the shroud 60. The width in the radial direction Dr of the ventral contact face 82 is smaller than the width in the radial direction Dr of the dorsal contact face 81.

[0102] The blade body 51 tends to deform so as to fall from the circumferential ventral side Dc2 to the circumferential dorsal side Dc1. For this reason, the end of the circumferential ventral side Dc2 of the shroud 60 approaches a stationary-side (tip-side) structure (for example, the honeycomb material 47) located on the radially outer side Dro with respect to the shroud 60. Further, when the end of the circumferential ventral side Dc2 of the shroud 60 undergoes creep deformation so as to turn up toward the radially outer side Dro due to creep deformation caused by centrifugal force, the ventral contact surface 82 of the shroud 60 may come into heavy contact with this stationary-side structure.

[0103] In the present embodiment, by thinning the end of the circumferential ventral side Dc2 of the shroud 60, it is possible to suppress the ventral contact surface 82 from coming into heavy contact with the stationary-side structure. Therefore, it is possible to suppress the problems caused by creep deformation.

[0104] In the present embodiment, the anti-gas path surface 64 in the region where the ventral contact surface 82 is located is positioned on the radially inner side Dri with respect to the anti-gas path surface 64 in the region where the dorsal contact surface 81 is located.

[0105] In the present embodiment, the ventral contact surface 82 can be arranged on the radially inner side Dri with respect to the dorsal contact surface 81. Thereby, it is possible to more reliably suppress the ventral contact surface 80 from coming into heavy contact with the stationary-side structure.

[0106] "Second Embodiment of the Rotating Blade" With reference to FIGS. 11 to 14, the rotating blade 250 according to the second embodiment of the present invention will be described. Among the configurations of the second embodiment, the configurations that are the same as those of the first embodiment will be given the same names and the same reference numerals, and the description thereof will be omitted as appropriate.

[0107] The rotor blade 250 of this embodiment includes a blade body 51, a platform 52, a blade root 53, and a shroud 260 shown in FIG. 11. The shroud 260 is provided at the radially outer end Dro of the blade body 51. The shroud 260 has a shroud body 261 and a seal fin 266. The shroud body 261 extends in the spreading direction Dt away from the blade body 51.

[0108] The shroud body 261 has a blade body connection region 262 and an outer edge side region 263. The outer edge of the blade body connection region 262 surrounds the blade body 51 from the outside in the radial direction Dr view. A plurality of air holes 290 are formed in the blade body connection region 262 at positions overlapping the blade body 51 in the radial direction Dr. The plurality of air holes 290 are formed at intervals along the blade body 51 in the radial direction Dr view.

[0109] The outer edge side region 263 is connected to the blade body connection region 262 and is formed outside the blade body connection region 262 in the spreading direction Dt. The outer edge side region 263 is provided so as to surround the blade body connection region 262 from the outside in the radial direction Dr view.

[0110] Also, as shown in FIG. 12, both the blade body connection region 262 and the outer edge side region 263 have a reverse gas path surface 264 and a gas path surface 265.

[0111] A seal fin 266 protruding in the radially outer direction Dro is formed on the reverse gas path surface 264. As shown in FIG. 11, the seal fin 266 is provided at the central portion of the shroud body 261 in the axial direction Da. The seal fin 266 is formed to extend in the circumferential direction Dc. The seal fin 266 divides the plurality of air holes 290 into a plurality of air holes 290 on the upstream side Dau of the axis with the seal fin 266 interposed therebetween and a plurality of air holes 290 on the downstream side Dad of the axis with the seal fin 266 interposed therebetween.

[0112] Further, the gas path surface 265 has a fillet surface 267. Also in this embodiment, the outer edge of the airfoil connection region 262 in the spreading direction Dt coincides with the fillet edge 267a which is the outer edge of the fillet surface 267 in the spreading direction Dt.

[0113] In addition, the outer edge side region 263 has an end face 268 that connects the edge of the anti-gas path surface 264 of the outer edge side region 263 and the edge of the gas path surface 265 of the outer edge side region 263. The end face 268 has a front end face 269, a rear end face 270, a dorsal end face 271, and a ventral end face 272.

[0114] The front end face 269 has a first front end face 269a and a second front end face 269b. The first front end face 269a is a surface that extends in the circumferential direction Dc and curves toward the upstream side Dau of the axis as it goes toward the circumferential dorsal side Dc1. The second front end face 269b extends further toward the circumferential dorsal side Dc1 from the end of the first front end face 269a on the circumferential dorsal side Dc1. The second front end face 269b is a surface that linearly inclines with respect to the first front end face 269a so as to gradually go toward the downstream side Dad of the axis as it goes toward the circumferential dorsal side Dc1.

[0115] The rear end face 270 extends in the circumferential direction Dc and curves toward the downstream side Dad of the axis as it goes toward the circumferential ventral side Dc2.

[0116] The dorsal end face 271 connects the end of the front end face 269 on the circumferential dorsal side Dc1 and the end of the rear end face 270 on the circumferential dorsal side Dc1. The dorsal end face 271 extends in a zigzag shape in the axial direction Da when viewed in the radial direction Dr. The dorsal end face 271 has a first dorsal end face 271a, a curved dorsal end face 271b, a second dorsal end face 271c, and a third dorsal end face 271d. The first dorsal end face 271a, the curved dorsal end face 271b, the second dorsal end face 271c, and the third dorsal end face 271d are arranged in this order from the upstream side Dau to the downstream side Dad of the axis.

[0117] The first dorsal end face 271a extends from the end of the circumferential dorsal side Dc1 of the front end face 269 to the downstream side Dad of the axis. The first dorsal end face 271a is inclined with respect to the front end face 269 so as to gradually face the circumferential ventral side Dc2 as it goes toward the downstream side Dad of the axis.

[0118] The curved dorsal end face 271b is provided at the end of the downstream side Dad of the axis of the first dorsal end face 271a. The curved dorsal end face 271b is curved in an arc shape so as to be concave toward the circumferential ventral side Dc2 in the radial direction Dr view. The curved dorsal end face 271b connects the first dorsal end face 271a and the second dorsal end face 271c.

[0119] The second dorsal end face 271c extends from the curved dorsal end face 271b to the downstream side Dad of the axis. The second dorsal end face 271c is inclined with respect to the first dorsal end face 271a so as to gradually face the circumferential dorsal side Dc1 as it goes toward the downstream side Dad of the axis.

[0120] The third dorsal end face 271d extends from the end of the downstream side Dad of the axis of the second dorsal end face 271c to the downstream side Dad of the axis. The third dorsal end face 271d is inclined with respect to the second dorsal end face 271c so as to gradually face the circumferential ventral side Dc2 as it goes toward the downstream side Dad of the axis. The end of the downstream side Dad of the third dorsal end face 271d is connected to the end of the circumferential dorsal side Dc1 of the rear end face 270.

[0121] The ventral end face 272 connects the end of the circumferential ventral side Dc2 of the front end face 269 and the end of the circumferential ventral side Dc2 of the rear end face 270. The ventral end face 272 extends in a zigzag shape in the axial direction Da in the radial direction Dr view. The ventral end face 272 has a first ventral end face 272a, a second ventral end face 272b, a curved ventral end face 272c, a third ventral end face 272d, and a fourth ventral end face 272e. The first ventral end face 272a, the second ventral end face 272b, the curved ventral end face 272c, the third ventral end face 272d, and the fourth ventral end face 272e are arranged in this order from the upstream side Dau of the axis to the downstream side Dad of the axis.

[0122] The first ventral end face 272a extends from the end of the circumferential ventral side Dc2 of the front end face 269 to the downstream side Dad of the axis. The first ventral end face 272a is inclined with respect to the front end face 269 so as to gradually face the circumferential ventral side Dc2 as it goes toward the downstream side Dad of the axis.

[0123] The second ventral end face 272b extends from the end of the first ventral end face 272a on the downstream side Dad of the axis to the downstream side Dad of the axis. The second ventral end face 272b is inclined with respect to the first ventral end face 272a so as to gradually face the circumferential dorsal side Dc1 as it goes toward the downstream side Dad of the axis. The connection part between the first ventral end face 272a and the second ventral end face 272b is at a position overlapping with the curved dorsal end face 271b and the circumferential direction Dc.

[0124] The curved ventral end face 272c is provided at the end of the second ventral end face 272b on the downstream side Dad of the axis. The curved ventral end face 272c is curved in an arc shape so as to be concave toward the circumferential dorsal side Dc1 in the view of the radial direction Dr. The curved ventral end face 272c connects the second ventral end face 272b and the third ventral end face 272d. The curved ventral end face 272c is at a position overlapping with the connection part between the second dorsal end face 271c and the third dorsal end face 271d and the circumferential direction Dc.

[0125] The third ventral end face 272d extends from the curved ventral end face 272c to the downstream side Dad of the axis. The third ventral end face 272d is inclined with respect to the second ventral end face 272b so as to gradually face the circumferential ventral side Dc2 as it goes toward the downstream side Dad of the axis.

[0126] The fourth ventral end face 272e extends from the end of the third ventral end face 272d on the downstream side Dad of the axis to the downstream side Dad of the axis. The fourth ventral end face 272e is inclined with respect to the third ventral end face 272d so as to gradually face the circumferential dorsal side Dc1 as it goes toward the downstream side Dad of the axis. The end of the fourth ventral end face 272e on the downstream side Dad of the axis is connected to the end of the circumferential ventral side Dc2 of the rear end face 270.

[0127] Also, in this embodiment as well, the outer edge side region 263 has a specific outer edge side region 274. The average thickness change rate in the specific outer edge side region 274 is larger than the thickness change rate at the region edge 262a that is in contact with the specific outer edge side region 274 in the airfoil connection region 262, similar to the first embodiment.

[0128] Also in this embodiment, the specific outer edge side region 274 is provided on both sides in the circumferential direction Dc with respect to the airfoil 51. Also, the region edge 262a that is in contact with the specific outer edge side region 274 in the airfoil connection region 262 in the spreading direction Dt is on the fillet edge 267a which is the outer edge of the fillet surface 267 in the spreading direction Dt.

[0129] Also, the specific outer edge side region 274 has a first outer edge side region 275 and a second outer edge side region 276.

[0130] Also in this embodiment, the average surface change rate on the gas path surface 265 of the first outer edge side region 275 is larger than the average surface change rate on the anti-gas path surface 264 of the first outer edge side region 275.

[0131] The first outer edge side region 275 is a region on the upstream side of the axis Dau in the shroud main body 261, and is a region of the circumferential dorsal side Dc1 where the dorsal surface 57 exists with respect to the ventral surface 56 in the circumferential direction Dc. The first outer edge side region 275 is located on both sides of the axis Ar with respect to the second dorsal end face 271c. The first outer edge side region 275 extends in the circumferential dorsal side Dc1 from the fillet edge 267a (the outer edge of the airfoil connection region 262) to the dorsal end face 271. Also, the first outer edge side region 275 extends downstream in the axial direction Da from the front end face 269.

[0132] On the gas path surface 265 of the first outer edge side region 275, a first recess 278 is formed. As shown in FIG. 13, the inner surface of the first recess 278 is curved so as to be gradually located in the radially outer direction Dro as it moves away from the airfoil 51. Due to this first recess 278, the average surface change rate on the gas path surface 265 of the first outer edge side region 275 is larger than the average surface change rate on the anti-gas path surface 264 of the first outer edge side region 275. The first recess 278 extends from the upstream end Dau of the axis of the first outer edge side region 275 to the downstream end Dad of the axis. From another perspective, the first recess 278 defines the width in the axial direction Da of the first outer edge side region 275. The first recess 278 is located upstream Dau of the axis from the curved back end face 271b. Further, the first recess 278 is formed so as to extend from the connection portion of the front end face 269 and the back end face 271 to the circumferential ventral side Dc2. The first recess 278 is formed in a trapezoidal shape when viewed in the radial direction Dr. The outer edge of the circumferential dorsal side Dc1 of the first recess 278 extends from the second front end face 269b to the downstream side Dad of the axis along the first dorsal end face 271a. The outer edge of the circumferential ventral side Dc2 of the first recess 278 extends substantially parallel to the outer edge of the circumferential dorsal side Dc1 of the first recess 278. The outer edge of the upstream side Dau of the axis of the first recess 278 extends along the second front end face 269b. The outer edge of the downstream side Dad of the axis of the first recess 278 extends from the curved back end face 271b to the circumferential dorsal side Dc1.

[0133] Also in this embodiment, the average surface change rate on the anti-gas path surface 264 of the second outer edge side region 276 is larger than the average surface change rate on the gas path surface 265 of the second outer edge side region 276.

[0134] The second outer edge side region 276 is a region on the upstream side Dau of the axis in the shroud body 261, and is a region of the circumferential ventral side Dc2 where the ventral surface 56 exists with respect to the dorsal surface 57 in the circumferential direction Dc. The second outer edge side region 276 is located on the upstream side Dau of the axis from the second ventral end face 272b, and extends in the circumferential ventral side Dc2 from the fillet edge 267a (the outer edge of the wing body connection region 262) to the ventral end face 272. Further, the second outer edge side region 276 extends downstream in the axial direction Da from the region on the downstream side Dad of the axis from the seal fin 266 on the upstream side Dau of the axis.

[0135] A second recess 279 is formed in the anti-gas path surface 264 of the second outer edge side region 276. As shown in FIG. 13, the inner surface of the second recess 279 is curved so as to be gradually located on the radially inner side Dri as it moves away from the wing body 51. Due to this second recess 279, the average surface change rate on the anti-gas path surface 264 of the second outer edge side region 276 is larger than the average surface change rate on the gas path surface 265 of the second outer edge side region 276. The second recess 279 extends from the end on the upstream side Dau of the axis of the second outer edge side region 276 to the end on the downstream side Dad of the axis. From another perspective, the second recess 279 defines the width of the second outer edge side region 276 in the axial direction Da. The second recess 279 is located on the upstream side Dau of the axis from the second ventral end face 272b of the ventral end face 272. Further, the second recess 279 is located on the circumferential ventral side Dc2 from the wing body 51 at the same position in the axial direction Da. The second recess 279 is formed in a parallelogram shape that extends in the axial direction Da in the radial direction Dr view and is located on the circumferential ventral side Dc2 as it goes toward the downstream side Dad of the axis. The outer edge on the downstream side Dad of the second recess 279 extends along the first front end face 269a. The outer edge on the circumferential ventral side Dc2 of the second recess 279 extends along the first ventral end face 272a.

[0136] Further, as shown in FIG. 11, air introduction recesses 291 are formed on both sides in the axial direction Da with the seal fin 266 interposed therebetween. Each air introduction recess 291 is formed to extend along the camber line in the radial direction Dr view. Each air introduction recess 291 communicates with a plurality of air holes 290 that extend in the radial direction Dr inside the wing body 51. The air introduction recess 291 opens toward the radially outer side Dro. The air introduction recess 291 is closed by a lid portion 292.

[0137] Also, as shown in FIG. 11, also in this embodiment, the dorsal end face 271 and the ventral end face 272 of the shroud 260 each have a contact surface 280 for connecting the shrouds 260 adjacent to each other in the circumferential direction Dc. The contact surface 280 of the dorsal end face 271 is defined as the dorsal contact surface 281, and the contact surface 280 of the ventral end face 272 is defined as the ventral contact surface 282. The dorsal contact surface 281 and the ventral contact surface 282 are formed at positions in the same axial direction Da.

[0138] The dorsal contact surface 281 is capable of contacting a part (ventral contact surface 282) of the ventral end face 272 of another shroud 260 located in the circumferential dorsal side Dc1 of the shroud 260. The dorsal contact surface 281 is a region including the second dorsal end face 271c of the dorsal end face 271. The dorsal contact surface 281 is located on the downstream side Dad of the axis from the curved dorsal end face 271b and on the upstream side Dau of the axis from the third dorsal end face 271d.

[0139] The ventral contact surface 282 is capable of contacting a part (dorsal contact surface 281) of the dorsal end face 271 of another shroud 260 located in the circumferential ventral side Dc2 of the shroud 260. The ventral contact surface 282 is a region including the second ventral end face 272b of the ventral end face 272. The ventral contact surface 282 is located on the downstream side Dad of the axis from the first ventral end face 272a and on the upstream side Dau of the axis from the curved ventral end face 272c.

[0140] As shown in FIG. 14, in this embodiment, a third recess 283 is formed at the position of the ventral contact surface 282 in the shroud body 261. The third recess 283 is located on the circumferential dorsal side Dc1 with respect to the blade body 51. Further, the third recess 283 is located on the downstream side Dad of the first ventral end surface 272a with respect to the axis and on the upstream side Dau of the seal fin 266 with respect to the axis. The third recess 283 is formed along the contact surface 280. Due to this third recess 283, the anti-gas path surface 264 in the region where the ventral contact surface 282 is located is located on the radially inner side Dri with respect to the anti-gas path surface 264 in the region where the dorsal contact surface 281 is located. As a result, the width in the radial direction Dr of the ventral contact surface 282 is smaller than the width in the radial direction Dr of the dorsal contact surface 281.

[0141] The moving blade 250 of the second embodiment is manufactured through a casting process S1 and a finishing process S2 by the same manufacturing method as that of the first embodiment.

[0142] Also, similar to the moving blade 50 of the first embodiment, the above-described moving blade 250 can also be obtained by machining an existing moving blade. The existing moving blade used here has first to third cutting portions 295, 296, 297, etc. shown in FIGS. 13 and 14 in addition to the configuration of the above-described moving blade 250.

[0143] The machining method of the moving blade of this embodiment is performed in the same procedure as the machining method of the moving blade of the first embodiment. Note that in this embodiment, in the machining method of the moving blade 250, the second cutting process S22 is omitted.

[0144] In this embodiment, in the first cutting process S21, as shown in FIG. 13, the first cutting portion 295 on the gas path surface 265 of the existing moving blade is cut off to form the first recess 278, and the second cutting portion 296 on the anti-gas path surface 264 of the existing moving blade is cut off to form the second recess 279. When the first recess 278 is formed, the first outer edge side region 275 is formed, and when the second recess 279 is formed, the second outer edge side region 276 is formed.

[0145] Also, in the third machining step S23, as shown in FIG. 14, a third machining portion 297 on the counter gas path surface 264 of the existing moving blade is machined away to form a third recess 283.

[0146] Also, in the finishing step S2a, in this embodiment as well, finishing processing is performed in the same manner as in the first embodiment. For example, a heat insulation coating is applied as necessary.

[0147] The moving blade 250 of the second embodiment described above can exhibit the same operational effects as the moving blade 50 of the first embodiment for the same configuration as that of the first embodiment.

[0148] (Other Embodiments) Although the embodiments of the present disclosure have been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes and the like within the scope not departing from the gist of the present disclosure are also included.

[0149] The moving blade 50 having the configuration described in the above embodiments and modification examples is the moving blade 50 of the gas turbine 10. However, the moving blade 50 having the configuration described in the above embodiments and modification examples is not limited to the moving blade 50 of the gas turbine 10, and may be a moving blade of other axial flow rotating machines, for example, a steam turbine.

[0150] In the above embodiment, the case where the specific outer edge side regions 74, 274 have the first outer edge side regions 75, 275 and the second outer edge side regions 76, 276 has been described. However, the specific outer edge side regions 74, 274 may include only one of the first outer edge side regions 75, 275 and the second outer edge side regions 76, 276. Also, the first outer edge side regions 75, 275 may be provided on the circumferential ventral side Dc2 of the shroud main bodies 61, 261, and the second outer edge side regions 76, 276 may be provided on the circumferential dorsal side Dc1 of the shroud main bodies 61, 261. Further, the first outer edge side regions 75, 275 and the second outer edge side regions 76, 276 may be provided on the downstream side Dad of the axis of the shroud main bodies 61, 261.

[0151] In the first embodiment, it is assumed that the first front end face 69a is provided on the circumferential ventral side Dc2 of the front end face 69, and the second front end face 69b is provided on the circumferential dorsal side Dc1 of the front end face 69. However, the present invention is not limited to this. The first front end face 69a may be provided on the circumferential dorsal side Dc1 of the front end face 69, and the second front end face 69b may be provided on the circumferential ventral side Dc2 of the front end face 69. Also, regarding the second embodiment, similar to the first embodiment, the first front end face 269a may be located on the upstream side Dau of the leading edge 54 with respect to the axis, and may be formed in the circumferential direction Dc centered on the axis Ar so as to extend in a direction perpendicular to the axis Ar. Further, the second front end face 269b may be formed as a surface inclined with respect to the first front end face 269a so as to gradually face the downstream side Dad of the axis as it moves away from the airfoil 51 in the circumferential direction Dc.

[0152] In the first embodiment, the case where the cooling flow path 93 is formed in the shroud body 61 has been described. However, the cooling flow path 93 may not be formed in the shroud body 61. Conversely, in the second embodiment, a cooling flow path similar to the cooling flow path 93 of the first embodiment may be formed in the shroud body 261.

[0153] The characteristic configurations of the moving blades 50 and 250 described above are also applicable to moving blades having shrouds with shapes different from those of the shrouds 60 and 260, and the position and range can be appropriately changed according to the shape of the applied shroud. For example, the position and range of the specific outer edge side region can be appropriately changed according to the shape of the applied shroud.

[0154] "Supplementary Note" The moving blades 50 and 250 in the above embodiments and modification examples can be understood as follows, for example.

[0155] (1) The moving blades 50 and 250 in the first aspect are In the moving blades 50 and 250 attached to the rotor shaft 42 centered on the axis Ar, a blade body 51 that extends in the radial direction Dr with respect to the axis Ar and has an airfoil cross-sectional shape perpendicular to the radial direction Dr, and shrouds 60 and 260 provided at the radially outer Dro ends of the blade body 51 with respect to the axis Ar are provided. The blade body 51 has a leading edge 54 on the most upstream side Dau in the axial direction Da in which the axis Ar extends, a trailing edge 55 on the most downstream side Dad, a ventral surface 56 that connects the leading edge 54 and the trailing edge 55 and is in a back-to-back relationship with each other, and a dorsal surface 57. The shrouds 60 and 260 have shroud bodies 61 and 261 that extend in a spreading direction Dt that has a component perpendicular to the radial direction Dr in which the blade body 51 extends and that spreads away from the blade body 51. The shroud bodies 61 and 261 have a blade connection region 62 and 262 that includes a region where the blade body 51 is connected, and an outer edge side region 63 and 263 that is connected to the blade connection region 62 and 262 and is formed outside the blade connection region 62 and 262 in the spreading direction Dt. Both the blade connection region 62 and 262 and the outer edge side region 63 and 263 have a counter gas path surface 64 and 264 facing the radially outer Dro and a gas path surface 65 and 265 facing the radially inner Dri with respect to the axis Ar. The gas path surface 65 and 265 of the blade connection region 62 and 262 is a curved surface in which the surface change rate, which is the ratio of the position change amount of the radial direction Dr per unit position change amount in the spreading direction Dt, gradually decreases as it goes in the spreading direction Dt. When the change amount of the thickness, which is the interval between the gas path surface 65 and 265 and the counter gas path surface 64 and 264 per unit position change amount in the spreading direction Dt, is defined as the thickness change rate, the average thickness change rate in a specific outer edge side region 74 and 274 in the outer edge side region 63 and 263 is larger than the thickness change rate in a region edge 62a and 262a in the blade connection region 62 and 262 that is in contact with the specific outer edge side region 74 and 274.

[0156] The outer edge side regions 63, 263 have a lower rigidity compared to the blade body connection regions 62, 262, and are prone to creep deformation due to centrifugal force. In this embodiment, the gas path surfaces 65, 265 of the blade body connection regions 62, 262 are curved surfaces where the surface change rate, which is the ratio of the position change amount in the radial direction Dr per unit position change amount in the spreading direction Dt, gradually decreases as it goes in the spreading direction Dt. Furthermore, the average thickness change rate in the specific outer edge side regions 74, 274 in the outer edge side regions 63, 263 is larger than the thickness change rate in the region edges 62a, 262a in the blade body connection regions 62, 262 that are in contact with the specific outer edge side regions 74, 274. For this reason, while smoothly connecting the outer edge side regions 63, 263 and the blade body connection regions 62, 262, the outer edge side regions 63, 263 are thinner than the blade body connection regions 62, 262. Thereby, while maintaining the aerodynamic characteristics, the outer edge side regions 63, 263 can be lightened. Thus, the centrifugal force applied to the outer edge side regions 63, 263 of the shrouds 60, 260 can be reduced, and the creep deformation that turns up in the radially outer side Dro can be suppressed. Therefore, problems due to creep deformation can be suppressed.

[0157] (2) The moving blades 50, 250 in the second embodiment are In the moving blades 50, 250 in the first embodiment, the specific outer edge side regions 74, 274 have first outer edge side regions 75, 275, and the average surface change rate of the first outer edge side regions 75, 275 on the gas path surface 65, 265 is larger than the average surface change rate of the first outer edge side regions 75, 275 on the reverse gas path surface 64, 264.

[0158] On the anti-gas path surfaces 64, 264, structures such as seal fins 66, 266 are formed to prevent leakage of the working fluid. Therefore, if the shape of the anti-gas path surfaces 64, 264 is changed, it is necessary to redesign the shape and arrangement of structures such as the seal fins 66, 266, which may lead to a performance decline. For this reason, changing the shape of the anti-gas path surfaces 64, 264 is considered unfavorable. In this embodiment, during design, only the shape of the gas path surface 65, 265 is changed without changing the shape of the anti-gas path surface 64, 264 in the first outer edge side regions 75, 275, so that the outer edge side regions 63, 263 can be made thinner than the airfoil connection regions 62, 262, and the outer edge side regions 63, 263 can be lightened.

[0159] (3) The moving blades 50, 250 in the third embodiment are In the moving blades 50, 250 in the second embodiment, the first outer edge side regions 75, 275 are regions on the upstream side Dau of the axis in the shroud main bodies 61, 261, and are regions of the circumferential dorsal side Dc1 where the dorsal surface 57 exists with respect to the ventral surface 56 in the circumferential direction Dc centered on the axis Ar.

[0160] In this embodiment, during design, only the shape of the gas path surface 65, 265 is changed without changing the shape of the anti-gas path surface 64, 264 on the upstream side Dau and circumferential dorsal side Dc1 of the axis of the shroud 60, 260, so that the outer edge side regions 63, 263 can be made thinner than the airfoil connection regions 62, 262, and the outer edge side regions 63, 263 can be lightened.

[0161] (4) The moving blades 50, 250 in the fourth embodiment are In the moving blades 50, 250 in any one of the first to third embodiments, the specific outer edge side regions 74, 274 have second outer edge side regions 76, 276, and the average surface change rate of the anti-gas path surface 64, 264 in the second outer edge side regions 76, 276 is larger than the average surface change rate of the gas path surface 65, 265 in the second outer edge side regions 76, 276.

[0162] The gas path surfaces 65, 265 through which the working fluid flows are preferably formed in a smooth shape with few irregularities in terms of aerodynamic characteristics. In this embodiment, during design, only the shape of the anti-gas path surfaces 64, 264 is changed without changing the shape of the gas path surfaces 65, 265 in the second outer edge side regions 76, 276, so that the outer edge side regions 63, 263 can be made thinner than the blade connection regions 62, 262, and the outer edge side regions 63, 263 can be lightened.

[0163] (5) The moving blades 50, 250 in the fifth aspect are In the moving blades 50, 250 in the fourth aspect, the second outer edge side regions 76, 276 are regions of the shroud main bodies 61, 261 on the upstream side Dau of the axis, and are regions of the circumferential ventral side Dc2 where the ventral side 56 exists with respect to the dorsal side 57 in the circumferential direction Dc centered on the axis Ar.

[0164] In this embodiment, during design, only the shape of the anti-gas path surfaces 64, 264 is changed without changing the shape of the gas path surfaces 65, 265 on the upstream side Dau and circumferential ventral side Dc2 of the shroud 60, 260, so that the outer edge side regions 63, 263 can be made thinner than the blade connection regions 62, 262, and the outer edge side regions 63, 263 can be lightened.

[0165] (6) The moving blades 50, 250 in the sixth aspect are In the moving blades 50, 250 in the fourth or fifth aspect, a cooling flow path 93 for circulating cooling air is formed in the shroud main body 61, 261, extending from the blade connection region 62, 262 in the spreading direction Dt, and the cooling flow path 93 opens in the spreading direction Dt at the anti-gas path surface 64, 264 in the second outer edge side region 76, 276.

[0166] If the cooling channel 93 opens to the gas path surface 65, 265 side and the inner surface of the cooling channel 93 is exposed, the exposed inner surface of the cooling channel 93 becomes a step of the gas path surface 65, 265, and the aerodynamic characteristics deteriorate. In this aspect, by opening the cooling channel 93 to the anti-gas path surface 64, 264 side, it is possible to suppress the exposure of the inner surface of the cooling channel 93 to the gas path surface 65, 265 side during design, and it is possible to suppress the deterioration of the aerodynamic characteristics.

[0167] (7) The moving blades 50, 250 in the seventh aspect are In the moving blades 50, 250 in any one of the first aspect to the sixth aspect, the gas path surface 65, 265 has fillet surfaces 67, 267 that extend so as to be gradually positioned on the radially outer side Dro in the spreading direction Dt from the ventral surface 56 and the dorsal surface 57 of the blade body 51, and the region edges 62a, 262a of the blade connection region 62, 262 in the spreading direction Dt are on the fillet edges 67a, 267a that are the outer edges of the fillet surfaces 67, 267 in the spreading direction Dt.

[0168] In the shroud body 61, 261, the region outside the fillet surfaces 67, 267 in the spreading direction Dt is more likely to undergo creep deformation due to centrifugal force than the region where the fillet surfaces 67, 267 are formed. In this aspect, a specific outer region can be formed to extend in the spreading direction Dt from the fillet edges 67a, 267a. Therefore, only the region outside the fillet surfaces 67, 267 in the spreading direction Dt, which is more likely to undergo creep deformation, can be lightened, and the amount of creep deformation can be reduced.

[0169] (8) The moving blade 50 in the eighth aspect is In the moving blade 50 according to any one of the first to seventh aspects, the outer edge side region 63 has an end face 68 connecting the edge of the anti-gas path surface 64 of the outer edge side region 63 and the edge of the gas path surface 65 of the outer edge side region 63. The end face 68 has a front end face 69 facing the upstream side Dau of the axis. The front end face 69 has a first front end face 69a and a second front end face 69b. The first front end face 69a is located on the upstream side Dau of the axis rather than the leading edge 54, and extends in the circumferential direction Dc centered on the axis Ar and in a direction perpendicular to the axis Ar. The second front end face 69b is a surface inclined with respect to the first front end face 69a so as to gradually face the downstream side Dad of the axis as it goes away from the blade body 51 in the circumferential direction Dc.

[0170] In this aspect, a second front end face 69b inclined with respect to the first front end face 69a is formed at the end of the shroud 60 on the upstream side Dau of the axis. Therefore, compared with the case where the front end face 69 extends in a straight line in a direction perpendicular to the axis Ar in the radial direction Dr view, the volume of the shroud 60 can be reduced, and the end of the shroud 60 on the upstream side Dau of the axis can be lightened. Thereby, the centrifugal force applied to the shroud 60 can be reduced, and the creep deformation that turns up to the outer side Dro in the radial direction of the shroud 60 can be suppressed. Therefore, problems due to creep deformation can be suppressed.

[0171] (9) The moving blade 50 in the ninth aspect is In the moving blade 50 according to the eighth aspect, the second front end face 69b is a surface located in the circumferential dorsal side Dc1 where the dorsal side 57 exists with respect to the ventral side 56 in the circumferential direction Dc with respect to the first front end face 69a. The second front end face 69b is a surface inclined with respect to the first front end face 69a so as to gradually face the downstream side Dad of the axis as it goes toward the circumferential dorsal side Dc1.

[0172] In this aspect, a second front end face 69b inclined with respect to the first front end face 69a is formed at the end of the shroud 60 on the upstream side Dau of the axis and on the circumferential back side Dc1. Therefore, the end of the shroud 60 on the upstream side Dau of the axis and on the circumferential back side Dc1 can be lightened.

[0173] (10) The moving blades 50, 250 in the tenth aspect are In the moving blades 50, 250 in any one of the first aspect to the ninth aspect, the outer edge side regions 63, 263 have end faces 68, 268 connecting the edge of the anti-gas path surface 64, 264 of the outer edge side regions 63, 263 and the edge of the gas path surface 65, 265 of the outer edge side regions 63, 263. The end faces 68, 268 face the circumferential back side Dc1 where the back side 57 exists with respect to the ventral side surface 56 in the circumferential direction Dc centered on the axis Ar and are located on the circumferential back side Dc1 rather than the blade body 51. They have dorsal end faces 71, 271 and ventral end faces 72, 272. The dorsal end faces 71, 271 have dorsal contact surfaces 81, 281 that can contact a part of the ventral end faces 72, 272 of the other shrouds 60, 260 located on the circumferential back side Dc1 of the shrouds 60, 260. The ventral end faces 72, 272 have ventral contact surfaces 82, 282 that can contact a part of the dorsal end faces 71, 271 of the other shrouds 60, 260 located on the circumferential ventral side Dc2 of the shrouds 60, 260. The width of the ventral contact surfaces 82, 282 in the radial direction Dr is smaller than the width of the dorsal contact surfaces 81, 281 in the radial direction Dr.

[0174] The blade body 51 tends to deform so as to fall from the circumferential ventral side Dc2 to the circumferential dorsal side Dc1. For this reason, the end of the circumferential ventral side Dc2 of the shrouds 60, 260 approaches a stationary structure (for example, the honeycomb material 47) located radially outside Dro than the shrouds 60, 260. Further, due to creep deformation caused by centrifugal force, if the end of the circumferential ventral side Dc2 of the shrouds 60, 260 undergoes creep deformation so as to turn up radially outside Dro, there is a risk that the ventral contact surfaces 82, 282 of the shrouds 60, 260 may come into heavy contact with this stationary structure.

[0175] In this aspect, the end of the circumferential ventral side Dc2 of the shrouds 60, 260 can be thinned, and it is possible to suppress the ventral contact surfaces 82, 282 from coming into heavy contact with the stationary structure. Therefore, it is possible to suppress the problems caused by creep deformation.

[0176] (11) The moving blades 50, 250 in the eleventh aspect are In the moving blades 50, 250 in the tenth aspect, the anti-gas path surfaces 64, 264 in the region where the ventral contact surfaces 82, 282 are located are located radially inside Dri than the anti-gas path surfaces 64, 264 in the region where the dorsal contact surfaces 81, 281 are located.

[0177] In this aspect, the ventral contact surfaces 82, 282 can be arranged radially inside Dri than the dorsal contact surfaces 81, 281. Thereby, it is possible to more reliably suppress the ventral contact surfaces 80, 280 from coming into heavy contact with the stationary structure.

[0178] (12) The moving blade 50 in the twelfth aspect is In the moving blade 50 attached to the rotor shaft 42 centered on the axis Ar, a blade body 51 extending in the radial direction Dr with respect to the axis Ar and having an airfoil cross-sectional shape perpendicular to the radial direction Dr, and a shroud 60 provided at the end on the outer side Dro in the radial direction with respect to the axis Ar in the blade body 51 are provided. The blade body 51 has a leading edge 54 on the most upstream side Dau in the axial direction Da in which the axis Ar extends, a trailing edge 55 on the most downstream side Dad, a ventral surface 56 and a dorsal surface 57 connecting the leading edge 54 and the trailing edge 55 and facing each other. The shroud 60 has a shroud body 61 extending in a direction having a component perpendicular to the radial direction Dr in which the blade body 51 extends and in a spreading direction Dt away from the blade body 51. The shroud body 61 has a reverse gas path surface 64 facing the outer side Dro in the radial direction, a gas path surface 65 facing the inner side Dri in the radial direction with respect to the axis Ar, and an end surface 68 connecting the edge of the reverse gas path surface 64 and the edge of the gas path surface 65. The end surface 68 has a front end surface 69 facing the upstream side Dau in the axis. The front end surface 69 has a first front end surface 69a and a second front end surface 69b. The first front end surface 69a is located on the upstream side Dau in the axis with respect to the leading edge 54 and extends in the circumferential direction Dc centered on the axis Ar in a direction perpendicular to the axis Ar. The second front end surface 69b is a surface inclined with respect to the first front end surface 69a so as to gradually face the downstream side Dad in the axis as it moves away from the blade body 51 in the circumferential direction Dc.

[0179] (13) The moving blade 50 in the thirteenth aspect is In the rotor blade 50 in the twelfth aspect, the end face 68 faces the circumferential dorsal side Dc1 where the dorsal surface 57 exists with respect to the ventral surface 56 in the circumferential direction Dc and is located on the circumferential dorsal side Dc1 rather than the airfoil 51, and a dorsal end face 71; and faces the circumferential ventral side Dc2 where the ventral surface 56 exists with respect to the dorsal surface 57 in the circumferential direction Dc and is located on the circumferential ventral side Dc2 rather than the airfoil 51, and a ventral end face 72. The dorsal end face 71 has a dorsal contact surface 81 that can contact a part of the ventral end face 72 of the other shroud 60 located on the circumferential dorsal side Dc1 of the shroud 60. The ventral end face 72 has a ventral contact surface 82 that can contact a part of the dorsal end face 71 of the other shroud 60 located on the circumferential ventral side Dc2 of the shroud 60. The width in the radial direction Dr of the ventral contact surface 82 is smaller than the width in the radial direction Dr of the dorsal contact surface 81.

[0180] (14) The rotor blades 50, 250 in the fourteenth aspect are In the moving blades 50 and 250 attached to the rotor shaft 42 centered on the axis Ar, a blade body 51 extending in the radial direction Dr with respect to the axis Ar and having an airfoil cross-sectional shape perpendicular to the radial direction Dr, and shrouds 60 and 260 provided at the radially outer ends Dro with respect to the axis Ar in the blade body 51. The blade body 51 has a leading edge 54 at the most upstream side Dau in the axial direction Da in which the axis Ar extends, a trailing edge 55 at the most downstream side Dad, a ventral surface 56 connecting the leading edge 54 and the trailing edge 55 and being in a back-to-back relationship, and a dorsal surface 57. The shrouds 60 and 260 have shroud bodies 61 and 261 that extend in a spreading direction Dt away from the blade body 51, which is a direction having a component perpendicular to the radial direction Dr in which the blade body 51 extends. The shroud bodies 61 and 261 have a reverse gas path surface 64 and 264 facing the radially outer side Dro, a gas path surface 65 and 265 facing the radially inner side Dri with respect to the axis Ar, and end faces 68 and 268 connecting the edge of the reverse gas path surface 64 and 264 and the edge of the gas path surface 65 and 265. The end faces 68 and 268 face a circumferential dorsal side Dc1 where the dorsal surface 57 exists with respect to the ventral surface 56 in the circumferential direction Dc centered on the axis Ar and are located on the circumferential dorsal side Dc1 further than the blade body 51, and have a dorsal end face 71 and 271. They also face a circumferential ventral side Dc2 where the ventral surface 56 exists with respect to the dorsal surface 57 in the circumferential direction Dc and are located on the circumferential ventral side Dc2 further than the blade body 51, and have a ventral end face 72 and 272. The dorsal end face 71 and 271 have a dorsal contact surface 81 and 281 that can contact a part of the ventral end face 72 and 272 of the other shroud 60 and 260 located on the circumferential dorsal side Dc1 of the shroud 60 and 260. The ventral end face 72 and 272 have a ventral contact surface 82 and 282 that can contact a part of the dorsal end face 71 and 271 of the other shroud 60 and 260 located on the circumferential ventral side Dc2 of the shroud 60 and 260. The width of the ventral contact surface 82 and 282 in the radial direction Dr is smaller than the width of the dorsal contact surface 81 and 281 in the radial direction Dr.

[0181] The method for machining the moving blade in the above-described embodiments and modified examples can be understood as follows, for example. (15) The method for machining the moving blade in the fifteenth aspect is In a method of machining the moving blades 50 and 250 attached to the rotor shaft 42 centered on the axis Ar, the moving blades 50 and 250 extend in the radial direction Dr with respect to the axis Ar, and include an airfoil body 51 having an airfoil-shaped cross-sectional shape perpendicular to the radial direction Dr, and shrouds 60 and 260 provided at the radially outer ends Dro with respect to the axis Ar in the airfoil body 51. The airfoil body 51 has a leading edge 54 at the most upstream side Dau in the axial direction Da in which the axis Ar extends, a trailing edge 55 at the most downstream side Dad, a ventral surface 56 connecting the leading edge 54 and the trailing edge 55 and being in a back-to-back relationship with each other, and a dorsal surface 57. The shrouds 60 and 260 have shroud bodies 61 and 261 that extend in a direction having a component perpendicular to the radial direction Dr in which the airfoil body 51 extends and spread in a spreading direction Dt away from the airfoil body 51. The shroud bodies 61 and 261 have an airfoil connection region 62 and 262 including a region where the airfoil body 51 is connected, and an outer edge side region 63 and 263 connected to the airfoil connection region 62 and 262 and formed outside the airfoil connection region 62 and 262 in the spreading direction Dt. The airfoil connection region 62 and 262 and the outer edge side region 63 and 263 each have a counter gas path surface 64 and 264 facing the radially outer side Dro and a gas path surface 65 and 265 facing the radially inner side Dri with respect to the axis Ar. The gas path surface 65 and 265 of the airfoil connection region 62 and 262 is a curved surface in which the surface change rate, which is the ratio of the position change amount of the radial direction Dr per unit position change amount in the spreading direction Dt, gradually decreases as it goes in the spreading direction Dt. When the change amount of the thickness, which is the interval between the gas path surface 65 and 265 and the counter gas path surface 64 and 264 per unit position change amount in the spreading direction Dt, is defined as the thickness change rate, at least one of the counter gas path surface 64 and 264 and the gas path surface 65 and 265 in the specific outer edge side region 74 and 274 in the outer edge side region 63 and 263 is machined so that the average thickness change rate in the specific outer edge side region 74 and 274 in the outer edge side region 63 and 263 is larger than the thickness change rate in the region edge 62a and 262a in the airfoil connection region 62 and 262 that is in contact with the specific outer edge side region 74 and 274.

[0182] (16) The method for machining the moving blade in the sixteenth aspect is In the method for machining the moving blade in the fifteenth aspect, the outer edge side region 63 has an end face 68 connecting the edge of the anti-gas path surface 64 of the outer edge side region 63 and the edge of the gas path surface 65 of the outer edge side region 63. The end face 68 has a front end face 69 facing the upstream side Dau of the axis. The front end face 69 has a first front end face 69a and a second front end face 69b. The first front end face 69a is located on the upstream side Dau of the axis relative to the leading edge 54 and extends in the circumferential direction Dc centered on the axis Ar in a direction perpendicular to the axis Ar. The front end face 69 is machined such that the second front end face 69b is a surface inclined with respect to the first front end face 69a so as to gradually face the downstream side Dad of the axis as it moves away from the blade body 51 in the circumferential direction Dc.

[0183] (17) The method for machining the moving blade in the seventeenth aspect is In the method for machining the moving blade according to the fifteenth or sixteenth aspect, the outer edge side regions 63, 263 have end faces 68, 268 that connect the edge of the anti-gas path face 64, 264 of the outer edge side regions 63, 263 and the edge of the gas path face 65, 265 of the outer edge side regions 63, 263. The end faces 68, 268 face the circumferential dorsal side Dc1 where the dorsal side face 57 exists with respect to the ventral side face 56 in the circumferential direction Dc centered on the axis Ar and are located on the circumferential dorsal side Dc1 with respect to the blade body 51. The end faces 68, 268 include a dorsal end face 71, 271 and a ventral end face 72, 272. The dorsal end face 71, 271 has a dorsal contact face 81, 281 that can contact a part of the ventral end face 72, 272 of the other shroud 60, 260 located on the circumferential dorsal side Dc1 of the shroud 60, 260. The ventral end face 72, 272 has a ventral contact face 82, 282 that can contact a part of the dorsal end face 71, 271 of the other shroud 60, 260 located on the circumferential ventral side Dc2 of the shroud 60, 260. At least one of the anti-gas path face 64, 264 and the gas path face 65, 265 in the region including the ventral contact face 82, 282 in the outer edge side region 63, 263 is machined so that the width in the radial direction Dr of the ventral contact face 82, 282 is smaller than the width in the radial direction Dr of the dorsal contact face 81, 281.

[0184] (18) The method for machining the moving blade according to the eighteenth aspect is In a method for machining a moving blade 50 attached to a rotor shaft 42 centered on an axis Ar, the moving blade 50 includes an airfoil 51 extending in a radial direction Dr with respect to the axis Ar and having an airfoil-shaped cross-sectional shape perpendicular to the radial direction Dr, and a shroud 60 provided at an end portion on the outer side Dro in the radial direction with respect to the axis Ar in the airfoil 51. The airfoil 51 has a leading edge 54 on the most upstream side Dau in the axial direction Da in which the axis Ar extends, a trailing edge 55 on the most downstream side Dad, a ventral surface 56 and a dorsal surface 57 connecting the leading edge 54 and the trailing edge 55 and facing each other. The shroud 60 has a shroud body 61 extending in a direction having a component perpendicular to the radial direction Dr in which the airfoil 51 extends and spreading in a spreading direction Dt away from the airfoil 51. The shroud body 61 has a counter gas path surface 64 facing the outer side Dro in the radial direction, a gas path surface 65 facing the inner side Dri in the radial direction with respect to the axis Ar, and an end surface 68 connecting an edge of the counter gas path surface 64 and an edge of the gas path surface 65. The end surface 68 has a front end surface 69 facing the upstream side Dau. The front end surface 69 has a first front end surface 69a and a second front end surface 69b. The first front end surface 69a is located on the upstream side Dau of the leading edge 54 and extends in a circumferential direction Dc centered on the axis Ar and perpendicular to the axis Ar. The front end surface 69 is machined such that the second front end surface 69b is inclined with respect to the first front end surface 69a so as to gradually face the downstream side Dad in the circumferential direction Dc as it moves away from the airfoil 51.

[0185] (19) The method for machining a moving blade in the nineteenth aspect is In the method for machining the moving blade according to the eighteenth aspect, the end face 68 faces the circumferential dorsal side Dc1 where the dorsal surface 57 exists with respect to the ventral surface 56 in the circumferential direction Dc and is located on the circumferential dorsal side Dc1 with respect to the blade body 51, and has a dorsal end face 71; and faces the circumferential ventral side Dc2 where the ventral surface 56 exists with respect to the dorsal surface 57 in the circumferential direction Dc and is located on the circumferential ventral side Dc2 with respect to the blade body 51, and has a ventral end face 72. The dorsal end face 71 has a dorsal contact surface 81 that can contact a part of the ventral end face 72 of the other shroud 60 located on the circumferential dorsal side Dc1 of the shroud 60. The ventral end face 72 has a ventral contact surface 82 that can contact a part of the dorsal end face 71 of the other shroud 60 located on the circumferential ventral side Dc2 of the shroud 60. At least one of the anti-gas path surface 64 and the gas path surface 65 in the region including the ventral contact surface 82 in the outer edge side region 63 of the shroud body 61 that is separated from the blade body 51 in the spreading direction Dt is machined so that the width in the radial direction Dr of the ventral contact surface 82 is smaller than the width in the radial direction Dr of the dorsal contact surface 81.

[0186] (20) The method for machining the moving blade according to the twentieth aspect is In a method for machining the moving blades 50, 250 attached to a rotor shaft 42 centered on an axis Ar, the moving blades 50, 250 include an airfoil body 51 that extends in a radial direction Dr with respect to the axis Ar and has an airfoil shape in a cross-sectional shape perpendicular to the radial direction Dr, and shrouds 60, 260 provided at the radially outer ends Dro with respect to the axis Ar in the airfoil body 51. The airfoil body 51 has a leading edge 54 at the most upstream side Dau in the axial direction Da in which the axis Ar extends, a trailing edge 55 at the most downstream side Dad, a ventral surface 56 that connects the leading edge 54 and the trailing edge 55 and is in a back-to-back relationship with each other, and a dorsal surface 57. The shrouds 60, 260 have shroud bodies 61, 261 that extend in a spreading direction Dt that has a component perpendicular to the radial direction Dr in which the airfoil body 51 extends and that spreads away from the airfoil body 51. The shroud bodies 61, 261 have a reverse gas path surface 64, 264 facing the radially outer side Dro, a gas path surface 65, 265 facing the radially inner side Dri with respect to the axis Ar, and end faces 68, 268 that connect the edge of the reverse gas path surface 64, 264 and the edge of the gas path surface 65, 265. The end faces 68, 268 face a circumferential dorsal side Dc1 where the dorsal surface 57 exists with respect to the ventral surface 56 in the circumferential direction Dc centered on the axis Ar and are located on the circumferential dorsal side Dc1 further than the airfoil body 51, and have dorsal end faces 71, 271, and face a circumferential ventral side Dc2 where the ventral surface 56 exists with respect to the dorsal surface 57 in the circumferential direction Dc and are located on the circumferential ventral side Dc2 further than the airfoil body 51, and have ventral end faces 72, 272. The dorsal end faces 71, 271 have dorsal contact surfaces 81, 281 that can contact a part of the ventral end faces 72, 272 of the other shrouds 60, 260 located on the circumferential dorsal side Dc1 of the shrouds 60, 260, and the ventral end faces 72, 272 have ventral contact surfaces 82, 282 that can contact a part of the dorsal end faces 71, 271 of the other shrouds 60, 260 located on the circumferential ventral side Dc2 of the shrouds 60, 260. The width of the ventral contact surface 82, 282 in the radial direction Dr is made smaller than the width of the dorsal contact surface 81, 281 in the radial direction Dr, and the shroud body 61,At least one of the anti-gas path surfaces 64, 264 and the gas path surfaces 65, 265 in the region including the ventral contact surfaces 82, 282 in the outer edge side regions 63, 263 spaced apart from the airfoil 51 in the spreading direction Dt in 261 is machined.,

Explanation of Signs

[0187] 10: Gas turbine 11: Gas turbine rotor 14: Intermediate casing 15: Gas turbine casing 20: Compressor 21: Compressor rotor 22: Rotor shaft 23: Moving blade row 25: Compressor casing 26: Stationary blade row 30: Combustor 40: Turbine 41: Turbine rotor 42: Rotor shaft 43: Moving blade row 45: Turbine casing 46: Stationary blade row 47: Honeycomb material 50, 250: Moving blade 51: Airfoil 52: Platform 53: Blade root 54: Leading edge 55: Trailing edge 56: Ventral surface 57: Dorsal surface 60, 260: Shroud 61, 261: Shroud body 62, 262: Airfoil connection region 62a, 262a: Region edge 63, 263: Outer edge side region 64, 264: Anti-gas path surface 65, 265: Gas path surface 66, 266: Seal fin 67, 267: Fillet surface 67a, 267a: Fillet edge 68, 268: End face 69,269: Front end face 69a,269a: First front end face 69b,269b: Second front end face 70,270: Rear end face 71,271: Dorsal end face 71a,271a: First dorsal end face 71b,271b: Curved dorsal end face 71c,271c: Second dorsal end face 71d,271d: Third dorsal end face 72,272: Ventral end face 72a,272a: First ventral end face 72b,272b: Second ventral end face 72c,272c: Curved ventral end face 72d,272d: Third ventral end face 272e: Fourth ventral end face 73: Protrusion 74,274: Specific outer edge side region 75,275: First outer edge side region 76,276: Second outer edge side region 78,278: First recess 79,279: Second recess 80,280: Contact surface 81,281: Dorsal contact surface 82,282: Ventral contact surface 83,283: Third recess 90,290: Air hole 91,291: Air inlet recess 92,292: Cover part 93: Cooling flow path 93a: First cooling flow path 93b: Second cooling flow path 93c: Third cooling flow path 95,295: First cut part 96,296: Second cut part 97,297: Third cut part 98: Fourth cut part A: Air F: Fuel G: Combustion gas Ar: Axis Da: Axial direction Dau: Upstream side of the axis Dad: Downstream side of the axis Dc: Circumferential direction Dc1: Back side in the circumferential direction Dc2: Front side in the circumferential direction Dr: Radial direction Dri: Inner side in the radial direction Dro: Outer side in the radial direction Dt: Spreading direction S1: Casting process S2, S2a: Finishing process S21: First machining process S22: Second machining process S23: Third machining process t: Thickness GEN: Generator

Claims

1. In a moving blade attached to a rotor shaft centered on an axis, a blade body that extends in a radial direction with respect to the axis and has an airfoil cross-sectional shape perpendicular to the radial direction; a shroud provided at an end portion on the outer side in the radial direction with respect to the axis in the blade body; comprising the blade body has a leading edge on the most upstream side of the axis in the axial direction in which the axis extends, a trailing edge on the most downstream side of the axis, a ventral surface and a dorsal surface that connect the leading edge and the trailing edge and are in a back-to-back relationship with each other; the shroud has a shroud body that has a component perpendicular to the radial direction in which the blade body extends and extends in a spreading direction away from the blade body; the shroud body has a blade body connection region including a region where the blade body is connected, and an outer edge side region that is connected to the blade body connection region and is formed outside the blade body connection region in the spreading direction; both the blade body connection region and the outer edge side region have a counter gas path surface facing the outer side in the radial direction and a gas path surface facing the inner side in the radial direction with respect to the axis; the gas path surface of the blade body connection region is a curved surface in which a surface change rate, which is a ratio of a position change amount in the radial direction per unit position change amount in the spreading direction, gradually decreases as it goes in the spreading direction; when a change amount of thickness, which is an interval between the gas path surface and the counter gas path surface per unit position change amount in the spreading direction, is defined as a thickness change rate, an average thickness change rate in a specific outer edge side region in the outer edge side region is larger than a thickness change rate at a region edge in the blade body connection region that is in contact with the specific outer edge side region; Moving blade.

2. In the moving blade according to Claim 1, the specific outer edge side region has a first outer edge side region, an average surface change rate on the gas path surface of the first outer edge side region is larger than an average surface change rate on the counter gas path surface of the first outer edge side region; Moving blade.

3. In the moving blade according to Claim 2, the first outer edge side region is a region on the upstream side of the axis in the shroud body and is a circumferentially dorsal region where the dorsal surface exists with respect to the ventral surface in the circumferential direction centered on the axis; Moving blade.

4. In the moving blade according to Claim 1 or 2, the specific outer edge side region has a second outer edge side region, The average surface change rate on the anti-gas path surface of the second outer edge side region is larger than the average surface change rate on the gas path surface of the second outer edge side region. Moving blade.

5. In the moving blade according to claim 4, The second outer edge side region is a region on the upstream side of the axis in the shroud body, and is a circumferential ventral region where the ventral surface exists with respect to the dorsal surface in the circumferential direction centered on the axis. Moving blade.

6. In the moving blade according to claim 4, A cooling flow path that extends from the blade body connection region in the spreading direction and allows cooling air to flow is formed in the shroud body. The cooling flow path opens in the spreading direction on the anti-gas path surface in the second outer edge side region. Moving blade.

7. In the moving blade according to claim 1 or 2, The gas path surface has a fillet surface that extends so as to be gradually located on the radially outer side as it goes from each of the ventral surface and the dorsal surface of the blade body in the spreading direction. The region edge of the blade body connection region in the spreading direction is on a fillet edge that is the outer edge of the fillet surface in the spreading direction. Moving blade.

8. In the moving blade according to claim 1, The outer edge side region has an end surface that connects the edge of the anti-gas path surface of the outer edge side region and the edge of the gas path surface of the outer edge side region. The end surface has a front end surface facing the upstream side of the axis. The front end surface has a first front end surface and a second front end surface. The first front end surface is located on the upstream side of the axis with respect to the leading edge, and spreads in the circumferential direction centered on the axis and in a direction perpendicular to the axis. The second front end surface is a surface inclined with respect to the first front end surface so as to gradually face the downstream side of the axis as it goes toward the side away from the blade body in the circumferential direction. Moving blade.

9. In the moving blade according to claim 8, The second front end surface is a surface located on the circumferential dorsal side where the dorsal surface exists with respect to the ventral surface in the circumferential direction with respect to the first front end surface. The second front end surface is a surface inclined with respect to the first front end surface so as to gradually face the downstream side of the axis as it goes toward the circumferential dorsal side. Moving blade.

10. In the moving blade according to claim 1, The outer edge side region has an end surface that connects the edge of the anti-gas path surface of the outer edge side region and the edge of the gas path surface of the outer edge side region. The end face has a dorsal end face that faces the circumferential dorsal side where the dorsal side is present with respect to the ventral side in the circumferential direction centered on the axis and is located on the circumferential dorsal side of the blade body, and a ventral end face that faces the circumferential ventral side where the ventral side is present with respect to the dorsal side in the circumferential direction and is located on the circumferential ventral side of the blade body. The dorsal end face has a dorsal contact surface that can contact a part of the ventral end face of the other shroud located on the circumferential dorsal side of the shroud. The ventral end face has a ventral contact surface that can contact a part of the dorsal end face of the other shroud located on the circumferential ventral side of the shroud. The radial width of the ventral contact surface is smaller than the radial width of the dorsal contact surface. Moving blade.

11. In the moving blade according to claim 10, The anti-gas path surface in the region where the ventral contact surface is located is located radially inward of the anti-gas path surface in the region where the dorsal contact surface is located. Moving blade.

12. In a moving blade attached to a rotor shaft centered on an axis, a blade body that extends in the radial direction with respect to the axis and has an airfoil cross-sectional shape perpendicular to the radial direction; a shroud provided at an end portion on the radially outer side with respect to the axis in the blade body; comprising The blade body has a leading edge on the most upstream side of the axis in the axial direction in which the axis extends, a trailing edge on the most downstream side of the axis, a ventral surface and a dorsal surface that connect the leading edge and the trailing edge and are in a back-to-back relationship. The shroud has a shroud body that extends in a direction having a component perpendicular to the radial direction in which the blade body extends and extends in a spreading direction away from the blade body. The shroud body has an anti-gas path surface facing the radially outer side, a gas path surface facing the radially inner side with respect to the axis, and an end face connecting the edge of the anti-gas path surface and the edge of the gas path surface. The end face has a front end face facing the upstream side of the axis. The front end face has a first front end face and a second front end face. The first front end face is located upstream of the axis with respect to the leading edge and extends in the circumferential direction centered on the axis and in a direction perpendicular to the axis. The second front end face is a surface inclined with respect to the first front end face so as to gradually face the downstream side of the axis as it goes in the circumferential direction away from the blade body. Moving blade.

13. In the moving blade according to claim 12, the end face has a dorsal end face that faces the circumferential dorsal side where the dorsal face exists with respect to the ventral face in the circumferential direction and is located on the circumferential dorsal side of the blade body, and a ventral end face that faces the circumferential ventral side where the ventral face exists with respect to the dorsal face in the circumferential direction and is located on the circumferential ventral side of the blade body, the dorsal end face has a dorsal contact surface that can contact a part of the ventral end face of the other shroud located on the circumferential dorsal side of the shroud, the ventral end face has a ventral contact surface that can contact a part of the dorsal end face of the other shroud located on the circumferential ventral side of the shroud, the width in the radial direction of the ventral contact surface is smaller than the width in the radial direction of the dorsal contact surface, Moving blade.

14. In a moving blade attached to a rotor shaft centered on an axis, a blade body that extends in the radial direction with respect to the axis and has an airfoil cross-sectional shape perpendicular to the radial direction, a shroud provided at an end portion on the outer side in the radial direction with respect to the axis in the blade body, comprising the blade body has a leading edge on the most upstream side in the axial direction among the upstream side and the downstream side in the axial direction in which the axis extends, a trailing edge on the most downstream side, and a ventral face and a dorsal face that connect the leading edge and the trailing edge and are in a back-to-back relationship with each other, the shroud has a shroud body that extends in a direction having a component perpendicular to the radial direction in which the blade body extends and extends in a spreading direction away from the blade body, the shroud body has a reverse gas path surface facing the outer side in the radial direction, a gas path surface facing the inner side in the radial direction with respect to the axis, and an end face connecting the edge of the reverse gas path surface and the edge of the gas path surface, the end face has a dorsal end face that faces the circumferential dorsal side where the dorsal face exists with respect to the ventral face in the circumferential direction centered on the axis and is located on the circumferential dorsal side of the blade body, and a ventral end face that faces the circumferential ventral side where the ventral face exists with respect to the dorsal face in the circumferential direction and is located on the circumferential ventral side of the blade body, the dorsal end face has a dorsal contact surface that can contact a part of the ventral end face of the other shroud located on the circumferential dorsal side of the shroud, the ventral end face has a ventral contact surface that can contact a part of the dorsal end face of the other shroud located on the circumferential ventral side of the shroud, The width in the radial direction on the ventral contact surface is smaller than the width in the radial direction on the dorsal contact surface. Moving blade.

15. In a method for machining a moving blade attached to a rotor shaft centered on an axis, The moving blade is An airfoil that extends in the radial direction with respect to the axis and has an airfoil shape in a cross-sectional shape perpendicular to the radial direction, A shroud provided at an end portion on the outer side in the radial direction with respect to the axis in the airfoil, Comprising The airfoil has a leading edge on the most upstream side of the axis in the axial direction in which the axis extends, a trailing edge on the most downstream side of the axis, a ventral surface and a dorsal surface that connect the leading edge and the trailing edge and are in a back-to-back relationship with each other. The shroud has a shroud body that extends in a direction having a component perpendicular to the radial direction in which the airfoil extends and extends in a spreading direction away from the airfoil. The shroud body has an airfoil connection region including a region where the airfoil is connected, and an outer edge side region connected to the airfoil connection region and formed outside the airfoil connection region in the spreading direction. Both the airfoil connection region and the outer edge side region have a counter gas path surface facing the outer side in the radial direction and a gas path surface facing the inner side in the radial direction with respect to the axis. The gas path surface of the airfoil connection region is a curved surface in which the surface change rate, which is the ratio of the position change amount in the radial direction per unit position change amount in the spreading direction, gradually decreases as it goes in the spreading direction. When the change amount of the thickness, which is the interval between the gas path surface and the counter gas path surface per unit position change amount in the spreading direction, is defined as the thickness change rate, at least one of the counter gas path surface and the gas path surface in the specific outer edge side region in the outer edge side region is machined so that the average thickness change rate in the specific outer edge side region in the outer edge side region is larger than the thickness change rate at the region edge in the airfoil connection region that is in contact with the specific outer edge side region. Method for machining a moving blade.

16. In the method for machining a moving blade according to claim 15, The outer edge side region has an end surface connecting the edge of the counter gas path surface of the outer edge side region and the edge of the gas path surface of the outer edge side region. The end surface has a front end surface facing the upstream side of the axis. The front end surface has a first front end surface and a second front end surface. The first front end face is located on the upstream side of the axis with respect to the leading edge, extends in the circumferential direction centered on the axis, and extends in a direction perpendicular to the axis. The front end face is machined such that the second front end face is a surface inclined with respect to the first front end face so as to gradually face the downstream side of the axis as it moves away from the blade body in the circumferential direction. A method for machining a moving blade.

17. In the method for machining a moving blade according to claim 15, The outer edge side region has an end face connecting the edge of the anti-gas path surface of the outer edge side region and the edge of the gas path surface of the outer edge side region. The end face has a back-side end face that faces the circumferential back side where the back side exists with respect to the ventral side face in the circumferential direction centered on the axis and is located on the circumferential back side of the blade body, and a ventral-side end face that faces the circumferential ventral side where the ventral side exists with respect to the back side face in the circumferential direction and is located on the circumferential ventral side of the blade body. The back-side end face has a back-side contact surface that can contact a part of the ventral-side end face of the other shroud located on the circumferential back side of the shroud. The ventral-side end face has a ventral-side contact surface that can contact a part of the back-side end face of the other shroud located on the circumferential ventral side of the shroud. At least one of the anti-gas path surface and the gas path surface in the region including the ventral-side contact surface in the outer edge side region is machined such that the radial width of the ventral-side contact surface is smaller than the radial width of the back-side contact surface. A method for machining a moving blade.

18. In a method for machining a moving blade attached to a rotor shaft centered on an axis, The moving blade includes: A blade body extending in the radial direction with respect to the axis and having an airfoil cross-sectional shape perpendicular to the radial direction; A shroud provided at the radially outer end of the blade body with respect to the axis; And comprises: The blade body has a leading edge on the most upstream side of the axis in the axial direction in which the axis extends, a trailing edge on the most downstream side of the axis, a ventral side face and a dorsal side face that connect the leading edge and the trailing edge and are in a back-to-back relationship with each other. The shroud has a shroud body that extends in a direction having a component perpendicular to the radial direction in which the blade body extends and extends in a spreading direction away from the blade body. The shroud body has a reverse gas path surface facing the radially outer side, a gas path surface facing the radially inner side with respect to the axis, and an end surface connecting the edge of the reverse gas path surface and the edge of the gas path surface. The end surface has a front end surface facing the upstream side of the axis. The front end surface has a first front end surface and a second front end surface. The first front end surface is located upstream of the axis with respect to the leading edge, extends in the circumferential direction centered on the axis, and extends in a direction perpendicular to the axis. The front end surface is machined such that the second front end surface is inclined with respect to the first front end surface so as to gradually face the downstream side of the axis as it moves away from the airfoil in the circumferential direction. A method for machining a moving blade.

19. In the method for machining a moving blade according to Claim 18, the end surface has a dorsal end surface facing the circumferential dorsal side where the dorsal surface exists with respect to the ventral surface in the circumferential direction and located on the circumferential dorsal side of the airfoil, and a ventral end surface facing the circumferential ventral side where the ventral surface exists with respect to the dorsal surface in the circumferential direction and located on the circumferential ventral side of the airfoil. The dorsal end surface has a dorsal contact surface that can contact a part of the ventral end surface of the other shroud located on the circumferential dorsal side of the shroud. The ventral end surface has a ventral contact surface that can contact a part of the dorsal end surface of the other shroud located on the circumferential ventral side of the shroud. At least one of the reverse gas path surface and the gas path surface in the region including the ventral contact surface in the outer edge region of the shroud body spaced apart from the airfoil in the spreading direction is machined such that the radial width of the ventral contact surface is smaller than the radial width of the dorsal contact surface. A method for machining a moving blade.

20. In a method for machining a moving blade attached to a rotor shaft centered on an axis, the moving blade includes an airfoil extending in the radial direction with respect to the axis and having an airfoil shape in a cross-sectional shape perpendicular to the radial direction, and a shroud provided at an end portion on the radially outer side of the airfoil with respect to the axis. The airfoil has a leading edge on the most upstream side of the axis in the axial direction in which the axis extends, a trailing edge on the most downstream side of the axis, a ventral surface and a dorsal surface connecting the leading edge and the trailing edge and facing each other back to back. ​ The shroud has a shroud body that extends in a direction having a component perpendicular to the radial direction in which the blade body extends and in a spreading direction away from the blade body. The shroud body has a reverse gas path surface facing the outside in the radial direction, a gas path surface facing the inside in the radial direction with respect to the axis, and an end surface connecting the edge of the reverse gas path surface and the edge of the gas path surface. The end surface has a dorsal end surface facing the circumferential dorsal side where the dorsal surface exists with respect to the ventral surface in the circumferential direction centered on the axis and located on the circumferential dorsal side of the blade body, and a ventral end surface facing the circumferential ventral side where the ventral surface exists with respect to the dorsal surface in the circumferential direction and located on the circumferential ventral side of the blade body. The dorsal end surface has a dorsal contact surface that can contact a part of the ventral end surface of the other shroud located on the circumferential dorsal side of the shroud. The ventral end surface has a ventral contact surface that can contact a part of the dorsal end surface of the other shroud located on the circumferential ventral side of the shroud. At least one of the reverse gas path surface and the gas path surface in the region including the ventral contact surface in the outer edge region of the shroud body separated from the blade body in the spreading direction is cut so that the width in the radial direction of the ventral contact surface is smaller than the width in the radial direction of the dorsal contact surface. A method for machining a moving blade.

Images