Turbine blade, turbine blade assembly, gas turbine, and method of repairing a gas turbine

Abstract

The present application reduces stress at a blade root of a turbine rotor blade. Either of a gap between a first base end side tooth and a second base end side tooth and a gap between the second base end side tooth and a third base end side tooth is larger than a gap between a first tip end side tooth and a second tip end side tooth. In a cross section orthogonal to an extending direction of the plurality of teeth, when a straight line connecting tooth bottoms formed between adjacent teeth in a blade height direction to each other is taken as a first straight line, an intersection of a second straight line including a linear portion of a tooth surface of a tip end side of each of the plurality of teeth and the first straight line is taken as a first intersection, and an intersection of a third straight line including a linear portion of a tooth surface of a base end side of each of the plurality of teeth and the first straight line is taken as a second intersection, a distance between the first intersection and the second intersection in the first base end side tooth is larger than a distance between the first intersection and the second intersection in a tooth other than the first base end side tooth.

Description

Technical Field

[0001] This disclosure relates to turbine blades, turbine blade assemblies, gas turbines, and methods for repairing gas turbines. Background Technology

[0002] The blade root of a turbine blade used in turbines such as gas turbines is a region repeatedly subjected to centrifugal stress caused by centrifugal loads transmitted from the airfoil and thermal stress caused by the temperature difference with the platform, and is therefore a stress concentration point. Thus, in order to suppress the reduction of the fatigue life of the turbine blade, designs have been developed to reduce the stress at the blade root (see, for example, Patent Document 1).

[0003] Prior art literature

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2021-131061

[0006] In the root of a blade with multiple teeth formed at different locations along the blade height, the stress can vary for each tooth. For example, there may be a case where the stress on the tooth at the base of the blade along the blade height is greater than that on other teeth. In this case, increasing the thickness of the tooth at the base increases its strength and reduces its stress, but this has the side effect of increasing the stress at the location where the tooth abuts against the blade slot forming the rotor disk. Therefore, when reducing the stress on the tooth by increasing its thickness, it is also necessary to consider stress suppression at that location. Summary of the Invention

[0007] At least one embodiment of this disclosure was made in view of the above circumstances, and its purpose is to reduce the stress at the root of the turbine blade while suppressing side effects.

[0008] (1) The turbine blade of at least one embodiment of the present disclosure comprises:

[0009] The wing-shaped part; and

[0010] At the base of the leaf, multiple teeth are formed at different positions along the leaf's height.

[0011] The plurality of teeth includes a base-end side first tooth, a base-end side second tooth, and a base-end side third tooth that extend along a direction intersecting the blade height direction and are arranged sequentially from the base end side in the blade height direction, and a front-end side first tooth and a front-end side second tooth that extend along the intersecting direction and are arranged sequentially from the front end side in the blade height direction.

[0012] The interval between the first tooth on the base side and the second tooth on the base side, and the interval between the second tooth on the base side and the third tooth on the base side, are both larger than the interval between the first tooth on the front end side and the second tooth on the front end side.

[0013] In a cross section orthogonal to the extension direction of the plurality of teeth, the straight line connecting the tooth bases of adjacent teeth formed in the blade height direction is taken as the first straight line.

[0014] In the cross-section, when the intersection of the second straight line, which includes the straight portion of the tooth surface on the front end side of each of the plurality of teeth, and the first straight line is taken as the first intersection point, and the intersection of the third straight line, which includes the straight portion of the tooth surface on the base end side of each of the plurality of teeth, and the first straight line is taken as the second intersection point,...

[0015] The distance between the first intersection point and the second intersection point in the first tooth on the base side is greater than the distance between the first intersection point and the second intersection point in the teeth other than the first tooth on the base side.

[0016] (2) The turbine blade assembly of at least one embodiment of the present disclosure includes:

[0017] The turbine blades of the structure described in (1) above; and

[0018] The rotor disk has blade grooves that can engage with the root of the turbine blade.

[0019] The blade groove has a base-end side first blade groove that can engage with the base-end side first tooth, a base-end side second blade groove that can engage with the base-end side second tooth, a base-end side third blade groove that can engage with the base-end side third tooth, a front-end side first blade groove that can engage with the front-end side first tooth, and a front-end side second blade groove that can engage with the front-end side second tooth.

[0020] When the tooth surface of the first tooth on the front end side is in close contact with the first blade groove on the front end side, a first gap is formed at least between the tooth surface of the first tooth on the front end side and the first blade groove on the base end side.

[0021] (3) The gas turbine of at least one embodiment of this disclosure comprises:

[0022] Multiple turbine blades, each having an airfoil and a blade root; and

[0023] The rotor disk has multiple blade slots that can engage with the root of the blades.

[0024] At least one of the plurality of turbine blades is a turbine blade with the structure described in (1) above.

[0025] (4) A method for repairing a gas turbine according to at least one embodiment of the present disclosure, wherein the gas turbine comprises: a plurality of turbine blades having airfoil portions and blade roots; and a rotor disk having a plurality of blade slots capable of engaging with the blade roots, wherein,

[0026] The repair method for the gas turbine includes a process of replacing at least one of the plurality of turbine blades mounted on the rotor disk with the turbine blades of the structure described above (1).

[0027] Invention Effects

[0028] According to at least one embodiment of this disclosure, stress at the root of the turbine blade can be reduced while suppressing side effects. Attached Figure Description

[0029] Figure 1 This is a schematic structural diagram of a gas turbine according to one embodiment.

[0030] Figure 2 This is a diagram of a turbine blade of one embodiment viewed from the direction of the leading edge toward the trailing edge (chord direction).

[0031] Figure 3 It is observed from the direction of the negative pressure side towards the pressure side (rotor circumference). Figure 2 The diagram shows a turbine blade.

[0032] Figure 4 It is shown Figure 3 A diagram of section AA.

[0033] Figure 5 It's enlarged. Figure 2 A schematic diagram of the engaging parts of each tooth and slot.

[0034] Figure 6 It's enlarged. Figure 2 A schematic diagram of the engaging parts of each tooth and slot.

[0035] Figure 7 It's enlarged. Figure 2 A schematic diagram of the engaging parts of each tooth and slot.

[0036] Explanation of reference numerals in the attached figures:

[0037] 1…gas turbine;

[0038] 6… turbine;

[0039] 24… Turbine blades;

[0040] 35…rotor disc;

[0041] 37…blade groove;

[0042] 44…wing-shaped section;

[0043] 50… leaf base;

[0044] 50a…end face;

[0045] 50b…bottom straight section;

[0046] 51… teeth;

[0047] 52, 55...tooth surface;

[0048] 52a, 55a… straight section;

[0049] 53…bottom of the tooth;

[0050] 54…receiving surface;

[0051] 90… Turbine blade assembly;

[0052] 381…First blade groove (first blade groove on the front end);

[0053] 382…Second blade groove (front-end side second blade groove);

[0054] 383… Third blade groove (base end side third blade groove);

[0055] 384… Fourth blade groove (second blade groove on the base side);

[0056] 385… Fifth blade groove (base end side first blade groove);

[0057] 511…First tooth (first tooth on the front side);

[0058] 511a, 511b, 511c, 511d, 511e… tooth surfaces;

[0059] 512…Second tooth (second tooth on the front side);

[0060] 513… Third tooth (third tooth on the basal side);

[0061] 514… Fourth tooth (second tooth on the basal side);

[0062] 515… Fifth tooth (first tooth on the basal side);

[0063] 515c…straight section of tooth tip;

[0064] 515d, 515e... curves. Detailed Implementation

[0065] Hereinafter, several embodiments of the present disclosure will be described with reference to the accompanying drawings. The dimensions, materials, shapes, and relative arrangements of the constituent components described as embodiments or shown in the drawings are not intended to limit the scope of the present disclosure, but are merely illustrative examples.

[0066] For example, expressions such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial" indicate a relative or absolute configuration, which not only strictly indicate such a configuration, but also indicate a state in which the relative displacement is within tolerance and to the extent that the same function can be obtained.

[0067] For example, expressions such as "same," "equal," and "homogeneous" that indicate the state of equality of things not only indicate a state of strict equality, but also indicate a state of difference in degree where there is a tolerance or the ability to obtain the same function.

[0068] For example, in this specification, the terms "quadrilateral shape," "cylindrical shape," etc., which describe shapes, not only refer to shapes in a strict geometric sense, but also include shapes such as concave and convex parts and chamfered parts within the range that can achieve the same effect.

[0069] On the other hand, expressions such as “having,” “possessing,” “having,” “including,” or “having” a constituent element are not exclusive expressions that exclude the existence of other constituent elements.

[0070] (Regarding the overall structure of gas turbine 1)

[0071] First, refer to Figure 1 The structure of a gas turbine with turbine blades according to one embodiment will be described. Figure 1 This is a schematic structural diagram of a gas turbine 1 according to one embodiment.

[0072] like Figure 1 As shown, one embodiment of the gas turbine 1 includes: a compressor 2 for generating compressed air; a combustor 4 for generating combustion gases using compressed air and fuel; and a turbine 6 configured to rotate driven by the combustion gases. In the case of the gas turbine 1 for power generation, a generator (not shown) is connected to the turbine 6, and power is generated using the rotational energy of the turbine 6.

[0073] exist Figure 1 In the gas turbine 1 shown, the compressor 2 has a rotor 30 that can rotate about the central axis AX, and a stator 5 arranged around the rotor 30.

[0074] The stator 5 has a compressor housing 10 and a plurality of compressor stator vanes 16 fixed to the side of the compressor housing 10.

[0075] The rotor 30 has a rotor shaft 8 capable of rotating about a central shaft AX, a plurality of rotor discs 31 fixed to the rotor shaft 8, and a plurality of compressor blades 18 respectively mounted on the plurality of rotor discs 31.

[0076] The rotor shaft 8 is configured to pass through both the compressor housing 10 and the turbine housing 22, which will be described later.

[0077] The compressor blades 18 are arranged in multiple segments circumferentially along the central axis AX on the outer periphery of each of the multiple rotor disks 31. Furthermore, the rotor disks 31 are arranged in multiple segments spaced apart in a direction parallel to the central axis AX. Therefore, the compressor blades 18 are arranged in multiple segments spaced apart in a direction parallel to the central axis AX.

[0078] Multiple compressor stationary vanes 16 are arranged around the central shaft AX. Furthermore, multiple segments of the compressor stationary vanes 16 are arranged at intervals in a direction parallel to the central shaft AX. The compressor stationary vanes 16 are arranged in multiple segments between the compressor moving vanes 18 in a direction parallel to the central shaft AX.

[0079] In addition, Figure 1 In the gas turbine 1 shown, the compressor 2 includes an air intake 12 located on the inlet side of the compressor compartment 10 for taking in air, and inlet guide vanes 14 located on the side of the air intake 12. It should be noted that the compressor 2 may also include other components such as an extraction chamber (not shown). In such a compressor 2, air taken in from the air intake 12 is compressed by multiple compressor stationary vanes 16 and multiple compressor moving vanes 18, thereby generating compressed air. The compressed air is then delivered from the compressor 2 to the downstream burner 4.

[0080] exist Figure 1 In the gas turbine 1 shown, the burner 4 is disposed within the casing (burner chamber) 20. For example... Figure 1 As shown, multiple burners 4 can also be arranged in a ring around the rotor shaft 8 within the housing 20. By supplying fuel and compressed air generated by the compressor 2 to the burners 4 and burning the fuel, high-temperature and high-pressure combustion gas is generated, which serves as the working fluid of the turbine 6. The combustion gas is then transported from the burners 4 to the downstream turbine 6.

[0081] exist Figure 1 In the gas turbine 1 shown, the turbine 6 has a rotor 33 that can rotate about the central axis AX, and a stator 7 arranged around the rotor 33.

[0082] The stator 7 has a turbine housing 22 and a plurality of turbine stator blades 26 fixed to the side of the turbine housing 22.

[0083] The rotor 33 has the aforementioned rotor shaft 8, a plurality of rotor disks 35 fixed to the rotor shaft 8, and a plurality of turbine blades 24 respectively mounted on the plurality of rotor disks 35.

[0084] The turbine blades 24 are arranged in multiple segments circumferentially along the central axis AX on the outer periphery of each of the multiple rotor disks 35. Furthermore, the rotor disks 35 are arranged in multiple segments spaced apart in a direction parallel to the central axis AX. Therefore, the turbine blades 24 are arranged in multiple segments spaced apart in a direction parallel to the central axis AX.

[0085] Multiple turbine stator vanes 26 are arranged circumferentially along the central axis AX. Furthermore, multiple segments of the turbine stator vanes 26 are arranged at intervals in a direction parallel to the central axis AX. The turbine stator vanes 26 are arranged in multiple segments between the turbine moving vanes 24 in a direction parallel to the central axis AX.

[0086] It should be noted that in turbine 6, rotor shaft 8 is axially ( Figure 1 The combustion gases extend from the burner 4 side to the exhaust chamber 28 side (in the left and right directions). Figure 1 The flow is from left to right (within the middle). Therefore, in Figure 1 In the diagram, the left side represents the upstream side of the axial direction, and the right side represents the downstream side of the axial direction. Furthermore, in the following explanations, when only axial direction is mentioned, it indicates the direction parallel to the central axis AX; when only radial direction is mentioned, it indicates the radial direction centered on the central axis AX. In the following explanations, when circumferential direction of the rotor is mentioned, or only circumferential direction is mentioned, it indicates the circumferential direction centered on the central axis AX.

[0087] The turbine rotor blade 24 is configured, together with the turbine stator blade 26, to generate rotational driving force from the high-temperature, high-pressure combustion gas flowing within the turbine housing 22. This rotational driving force is transmitted to the rotor shaft 8, thereby driving a generator (not shown) connected to the rotor shaft 8.

[0088] An exhaust chamber 29 is connected to the turbine housing 22 on the axial downstream side via an exhaust chamber 28. The combustion gases after driving the turbine 6 are discharged to the outside through the exhaust chamber 28 and the exhaust chamber 29.

[0089] (Structure of turbine blade 24)

[0090] Next, a turbine blade 24 according to one embodiment will be described. In the following description, the turbine blade 24 of the turbine 6 of the gas turbine 1 will be described as a turbine blade 24 according to one embodiment, but in other embodiments, the turbine blade may also be a turbine blade of a steam turbine.

[0091] Figure 2This is a diagram showing the turbine blade 24 of one embodiment viewed from the leading edge toward the trailing edge (chord direction). Figure 3 It is observed from the direction of the negative pressure side towards the pressure side (rotor circumference). Figure 2 The schematic diagram shown is of the turbine blade 24. Figure 4 It is shown Figure 3 The diagram shows the AA section. It should be noted that... Figure 2 The illustration shows the rotor disk 35 and turbine blades 24 of the turbine 6.

[0092] like Figures 2-4 As shown, one embodiment of the turbine blade 24 includes a platform 42, an airfoil 44 located on opposite sides of each other in the blade height direction (also known as the span direction) across the platform 42, a blade root 50, and a shank 60 located between the platform 42 and the blade root 50. The airfoil 44, platform 42, blade root 50, and shank 60 can be integrally formed by casting or the like.

[0093] It should be noted that when the turbine blade 24 is mounted on the rotor disk 35, the blade height direction of the turbine blade 24 is aligned with the radial direction. In the following description, the leading edge side in the blade height direction refers to the outer radial direction of the turbine blade 24 when it is mounted on the rotor disk 35, and the base side in the blade height direction refers to the inner radial direction of the turbine blade 24 when it is mounted on the rotor disk 35. Furthermore, in the following description, the leading edge side in the blade height direction will be simply referred to as the leading edge side, and the base side in the blade height direction will be simply referred to as the base side.

[0094] The airfoil 44 is configured to extend relative to the rotor disk 35 in the blade height direction. The airfoil 44 has a leading edge 46 and a trailing edge 48 extending in the blade height direction, and a pressure surface 41 and a negative pressure surface 43 extending between the leading edge 46 and the trailing edge 48. Figure 4 As shown, a hollow portion 34 can be formed inside the airfoil portion 44. The hollow portion 34 can function as a cooling passage for the flow of cooling fluid for cooling the airfoil portion 44.

[0095] like Figure 2 As shown, in the turbine 6, the blade root 50 engages with the blade groove 37 provided on the rotor disk 35. In this way, the turbine blade 24 is mounted on the rotor disk 35 of the turbine 6 and rotates together with the rotor disk 35 around the central axis AX.

[0096] (50 cm from the base of the leaf)

[0097] In one embodiment of the turbine blade 24, the blade root 50 has a plurality of teeth 51 formed at different positions in the blade height direction. The plurality of teeth 51 extend in a direction intersecting the blade height direction, i.e., the extending direction of the blade root 50, and the tooth tips 51a protrude in the width direction of the blade root 50.

[0098] It should be noted that, in this specification, the "width direction" of the blade root 50 refers to the direction that runs across the turbine blade 24 from the pressure surface 41 side of the airfoil 44 to the negative pressure surface 43 side (or from the negative pressure surface 43 side to the pressure surface 41 side). The width direction of the blade root 50 corresponds to the circumferential direction of the rotor 33.

[0099] In one embodiment of the turbine blade 24, five teeth 51, positioned differently in the blade height direction, are provided on one side and the other side of the blade root 50 in the width direction. The five teeth 51 positioned differently in the blade height direction are, from the front end side, a first tooth 511, a second tooth 512, a third tooth 513, a fourth tooth 514, and a fifth tooth 515.

[0100] The positions of the multiple teeth 51 approach the center of the blade root 50 in the width direction as they move from the leading edge side in the blade height direction toward the base side.

[0101] It should be noted that the first tooth 511 is also called the first tooth on the front end side, and the second tooth 512 is also called the second tooth on the front end side. In addition, the fifth tooth 515 is also called the first tooth on the base end side, the fourth tooth 514 is also called the second tooth on the base end side, and the third tooth 513 is also called the third tooth on the base end side.

[0102] In the blade slot 37 of the rotor disk 35, five blade slots 38 are formed on one side and the other side of the blade root 50 in the width direction, with positions different from those in the blade height direction. Each slot engages with a tooth 51. Of the five blade slots 38, the slot that engages with the first tooth 511 is the first blade slot 381, the slot that engages with the second tooth 512 is the second blade slot 382, ​​the slot that engages with the third tooth 513 is the third blade slot 383, the slot that engages with the fourth tooth 514 is the fourth blade slot 384, and the slot that engages with the fifth tooth 515 is the fifth blade slot 385.

[0103] It should be noted that the first blade groove 381 is also called the front-end side first blade groove, and the second blade groove 382 is also called the front-end side second blade groove. In addition, the fifth blade groove 385 is also called the base-end side first blade groove, the fourth blade groove 384 is also called the base-end side second blade groove, and the third blade groove 383 is also called the base-end side third blade groove.

[0104] In one embodiment of the turbine blade 24, the blade root 50 has a receiving surface 54. The receiving surface 54 is the portion of the surface of each tooth 51 that contacts the surface of each blade slot 38 of the rotor disk 35 when the rotor disk 35 rotates and exerts a centrifugal force on the turbine blade 24. That is, the receiving surface 54 is the surface in the blade height direction facing from the blade root 50 toward the airfoil portion 44 (i.e., the surface facing radially outward).

[0105] like Figure 4 As shown, the blade root 50 can also extend at an angle relative to the axial direction. That is, the blade root 50 of the turbine blade 24 can also be inserted into the blade slot 37 in the rotor disk 35, which is provided at an angle relative to the axial direction.

[0106] The blade root 50 of the turbine rotor blade 24 is repeatedly subjected to centrifugal stress caused by the centrifugal load transmitted from the airfoil 44 and thermal stress caused by the temperature difference with the platform 42. In the blade root 50 having multiple teeth 51 formed at different positions in the blade height direction, sometimes the stress of each tooth 51 is different. For example, there is a case where the stress of the tooth 51 (fifth tooth 515) on the base side in the blade height direction is greater than that of the other teeth 51. In this case, if the thickness of the tooth on the base side (fifth tooth 515) is increased, the strength of the tooth (fifth tooth 515) increases and the stress decreases, but this produces the side effect of increased stress at the location of the blade groove 38 (fifth blade groove 385) of the rotor disk 35 that abuts against the tooth (fifth tooth 515). Therefore, when reducing the stress of the tooth (fifth tooth 515) by increasing its thickness, it is also necessary to consider suppressing the stress at this location.

[0107] Therefore, in one embodiment of the turbine blade 24, in order to achieve the objective of this application, which is to reduce the stress of the fifth tooth 515 and suppress the stress at the location where the fifth blade groove 385 is formed in the rotor disk 35, the shape of each tooth 51 is set as follows.

[0108] Figure 5 It's enlarged. Figure 2 A schematic diagram of the engagement part between each tooth 51 and each blade groove 38.

[0109] In one embodiment of the turbine blade 24, the spacing I between the first tooth (fifth tooth 515) on the base end side and the second tooth (fourth tooth 514) on the base end side is... 45 and the interval I between the second tooth (fourth tooth 514) on the base side and the third tooth (third tooth 513) on the base side. 34 The distance I between the first tooth (first tooth 511) and the second tooth (second tooth 512) on either side of the front end is... 12 big.

[0110] Here, the interval I between the first tooth (first tooth 511) and the second tooth (second tooth 512) on the front end side is... 12 The distance between the front tooth surface 511a of the first tooth 511 (i.e., the bearing surface 54 of the first tooth 511) and the front tooth surface 512a of the second tooth 512 (i.e., the bearing surface 54 of the second tooth 512).

[0111] Similarly, the interval I between the second tooth (second tooth 512) and the third tooth (third tooth 513) on the front end side 23 The distance between the front tooth surface 512a (i.e., the bearing surface 54 of the second tooth 512) and the front tooth surface 513a (i.e., the bearing surface 54 of the third tooth 513) is the distance between the front tooth surface 512a (i.e., the bearing surface 54 of the third tooth 513).

[0112] The interval I between the first tooth (fifth tooth 515) on the basal side and the second tooth (fourth tooth 514) on the basal side 45 The distance between the front tooth surface 515a of the fifth tooth 515 (i.e., the bearing surface 54 of the fifth tooth 515) and the front tooth surface 514a of the fourth tooth 514 (i.e., the bearing surface 54 of the fourth tooth 514).

[0113] The interval I between the second tooth (fourth tooth 514) on the basal side and the third tooth (third tooth 513) on the basal side 34 The distance between the front tooth surface 514a of the fourth tooth 514 (i.e., the bearing surface 54 of the fourth tooth 514) and the front tooth surface 513a of the third tooth 513 (i.e., the bearing surface 54 of the third tooth 513).

[0114] In the section orthogonal to the extension direction of multiple teeth 51, i.e. Figure 5 In the schematic cross section shown, the straight line connecting the tooth bases 53 formed between adjacent teeth 51 in the blade height direction is taken as the first straight line L1.

[0115] In the above cross section, the intersection point of the second straight line L2, which includes the straight portion 52a of the front end side of the tooth surface 52 of each of the plurality of teeth 51, and the first straight line L1 is taken as the first intersection point P1.

[0116] The intersection point of the third straight line L3, which includes the straight portion 55a of the tooth surface 55 on the base side of each of the multiple teeth 51, and the first straight line L1 is taken as the second intersection point P2.

[0117] It should be noted that in one embodiment of the turbine blade 24, the shape of each tooth 51 is set such that the straight line connecting the bottoms 53 of two adjacent teeth is entirely consistent with the first straight line L1. This allows for appropriate load distribution among the teeth 51.

[0118] In one embodiment of the turbine blade 24, the distance A5 between the first intersection point P1 and the second intersection point P2 in the first tooth (fifth tooth 515) on the base end side is greater than the distances A1, A2, A3, and A4 between the first intersection point P1 and the second intersection point P2 in the teeth 51 other than the first tooth (fifth tooth 515) on the base end side.

[0119] It should be noted that the distance between the first intersection point P1 and the second intersection point P2 in the first tooth 511 is A1, the distance between the first intersection point P1 and the second intersection point P2 in the second tooth 512 is A2, the distance between the first intersection point P1 and the second intersection point P2 in the third tooth 513 is A3, and the distance between the first intersection point P1 and the second intersection point P2 in the fourth tooth 514 is A4.

[0120] According to one embodiment of the turbine blade 24, since the distance A5 between the first intersection point P1 and the second intersection point P2 in the first tooth (fifth tooth 515) on the base end side is greater than the distances A1, A2, A3, and A4 between the first intersection point P1 and the second intersection point P2 in the teeth 51 other than the first tooth (fifth tooth 515) on the base end side, the thickness of the first tooth (fifth tooth 515) on the base end side is greater than the thickness of the teeth 51 other than the first tooth (fifth tooth 515) on the base end side. Therefore, stress at the first tooth (fifth tooth 515) on the base end side can be suppressed.

[0121] The rotor disk 35, having blade slots 37 capable of engaging with the blade root 50 of the turbine blade 24, has multiple blade slots 38 capable of engaging with multiple teeth 51 formed at different positions in the blade height direction. In a typical rotor disk, the spacing between adjacent blade slots 38 in the blade height direction (radial direction of the rotor disk 35) is the same for any two adjacent blade slots in the radial direction of the rotor disk.

[0122] It should be noted that the spacing between adjacent blade slots 38 in the radial direction of the rotor disk 35 is, for example, the spacing between the surfaces of the blade slots 38 that face the bearing surfaces 54 of each tooth 51. In one embodiment of the turbine 6, the spacing between adjacent blade slots 38 in the radial direction of the rotor disk 35 is the same for any two radially adjacent blade slots 38 of the rotor disk 35.

[0123] Therefore, if the interval I between the first tooth (fifth tooth 515) on the base side and the second tooth (fourth tooth 514) on the base side is... 45 The distance I between the first tooth (first tooth 511) and the second tooth (second tooth 512) on the front end side. 12If the rotational speed of the rotor disk 35 is sufficiently small, when the tooth surface 511a of the front end side of the first tooth (first tooth 511) is in close contact with the blade groove 38 (first blade groove 381) that engages with the first tooth (first tooth 511), a gap g is formed between the tooth surface 515a of the front end side of the first tooth (fifth tooth 515) and the blade groove 38 (fifth blade groove 385) that engages with the first tooth (fifth tooth 515).

[0124] Additionally, if the interval I between the second tooth (fourth tooth 514) and the third tooth (third tooth 513) on the base side is... 34 The distance I between the first tooth (first tooth 511) and the second tooth (second tooth 512) on the front end side. 12 If the rotational speed of the rotor disk 35 is sufficiently small, when the tooth surface 511a of the front end side of the first tooth (first tooth 511) is in close contact with the blade groove 38 (first blade groove 381) that engages with the first tooth (first tooth 511), a gap g is formed between the tooth surface 515a of the front end side of the first tooth (fifth tooth 515) and the blade groove 38 (fifth blade groove 385) that engages with the first tooth (fifth tooth 515), and between the tooth surface 514a of the front end side of the second tooth (fourth tooth 514) and the blade groove 38 (fourth blade groove 384) that engages with the second tooth (fourth tooth 514).

[0125] It should be noted that, in Figure 5 In the example shown, the interval 1 between the second tooth (fourth tooth 514) on the base side and the third tooth (third tooth 513) on the base side is... 34 The distance I between the first tooth (first tooth 511) and the second tooth (second tooth 512) on the front end side. 12 Big. In Figure 5 In the example shown, the spacing I between the first tooth (fifth tooth 515) on the base side and the second tooth (fourth tooth 514) on the base side 45 The interval I between the first tooth (first tooth 511) and the second tooth (second tooth 512) on the front end side 12 Equal. Figure 5 In the example shown, the spacing I between the second tooth on the front end side (second tooth 512) and the third tooth on the base end side (third tooth 513) is... 23 The interval 1 between the first tooth (first tooth 511) and the second tooth (second tooth 512) on the front side. 12 equal.

[0126] Therefore, when the turbine blade 24 of one embodiment is installed on a rotor disk 35 having the same structure as a general rotor disk, and the rotational speed of the rotor disk 35 is sufficiently low, when the tooth surface 511a of the front end side of the first tooth (first tooth 511) is in close contact with the blade groove 38 (first blade groove 381) for engaging the first tooth (first tooth 511), a gap g is formed between the tooth surface 515a of the front end side of the first tooth (fifth tooth 515) and the blade groove 38 (fifth blade groove 385) for engaging the first tooth (fifth tooth 515). Therefore, according to the turbine blade 24 of one embodiment, the gap I between the first tooth (fifth tooth 515) and the second tooth (fourth tooth 514) on the base end side is... 45 and the interval I between the second tooth (fourth tooth 514) on the base side and the third tooth (third tooth 513) on the base side. 34 The interval between the first tooth (first tooth 511) and the second tooth (second tooth 512) on the front side is 1. 12 Compared to the same case, it is possible to reduce the stress at the blade groove 38 (fifth blade groove 385) of the rotor disk 35 that abuts against the first tooth (fifth tooth 515) on the base end side when subjected to centrifugal stress caused by centrifugal load transmitted from the airfoil 44, as well as the stress at the first tooth (fifth tooth 515) on the base end side.

[0127] Therefore, in one embodiment of the turbine blade 24, the thickness of the first tooth (fifth tooth 515) on the base end side is greater than the thickness of the other teeth 51 on the base end side, thereby suppressing the stress at the first tooth (fifth tooth 515) on the base end side. Furthermore, in one embodiment of the turbine blade 24, the aforementioned side effects caused by the thickness of the first tooth (fifth tooth 515) on the base end side being greater than the thickness of the other teeth 51 on the base end side can be suppressed.

[0128] In one embodiment of the turbine blade 24, the distance A5 between the first intersection point P1 and the second intersection point P2 in the first tooth (fifth tooth 515) on the base end side is preferably 101% or more and 105% or less of the distance A4 between the first intersection point P1 and the second intersection point P2 in the second tooth (fourth tooth 514) on the base end side.

[0129] As described above, increasing the thickness of the base-end tooth 51 (fifth tooth 515) increases its strength and decreases its stress, but it also increases the stress at the location of the blade groove 38 (fifth blade groove 385) of the rotor disk 35 that abuts against the tooth (fifth tooth 515). As described above, by increasing the spacing I between the base-end first tooth (fifth tooth 515) and the base-end second tooth (fourth tooth 514)... 45and the interval I between the second tooth (fourth tooth 514) on the base side and the third tooth (third tooth 513) on the base side. 34 The interval between the first tooth (first tooth 511) and the second tooth (second tooth 512) on either side of the front end is 1. 12 Larger diameters can suppress the aforementioned side effects. However, if the distance between the first tooth (fifth tooth 515) and the second tooth (fourth tooth 514) on the base side is increased by I... 45 and the interval 1 between the second tooth (fourth tooth 514) on the base side and the third tooth (third tooth 513) on the base side. 34 The distance I between the first tooth (first tooth 511) and the second tooth (second tooth 512) on either side of the front end is... 12 If the size is too large, it will cause other side effects such as increased stress at the part of the blade groove 38 that can engage with the tooth 51 on the front end side of the first tooth (fifth tooth 515) or the second tooth (fourth tooth 514) on the base end side.

[0130] The inventors, through in-depth research, determined that if the distance A5 between the first intersection point P1 and the second intersection point P2 in the first tooth (fifth tooth 515) on the base side is more than 101% and less than 105% of the distance A4 between the first intersection point P1 and the second intersection point P2 in the second tooth (fourth tooth 514) on the base side, then by appropriately setting the interval I between the first tooth (fifth tooth 515) and the second tooth (fourth tooth 514) on the base side... 45 and the interval I between the second tooth (fourth tooth 514) on the base side and the third tooth (third tooth 513) on the base side. 34 It can suppress the aforementioned side effects as well as other side effects.

[0131] Therefore, it is possible to suppress the local increase of stress acting on the rotor disk 35, and to suppress the stress at the first tooth (fifth tooth 515) on the base end side.

[0132] In one embodiment of the turbine blade 24, the distance A5 between the first intersection point P1 and the second intersection point P2 in the first tooth (fifth tooth 515) on the base end side is preferably 102% or more and 104% or less of the distance A4 between the first intersection point P1 and the second intersection point P2 in the second tooth (fourth tooth 514) on the base end side.

[0133] The inventors, through in-depth research, determined that if the distance A5 between the first intersection point P1 and the second intersection point P2 in the first tooth (fifth tooth 515) on the base end side is more than 102% and less than 104% of the distance A4 between the first intersection point P1 and the second intersection point P2 in the second tooth (fourth tooth 514) on the base end side, then by appropriately setting the interval I between the first tooth (fifth tooth 515) and the second tooth (fourth tooth 514) on the base end side... 45and the interval I between the second tooth (fourth tooth 514) on the base side and the third tooth (third tooth 513) on the base side. 34 This can further suppress the other side effects mentioned above.

[0134] Therefore, it is possible to further suppress the local increase of stress acting on the rotor disk 35, and to suppress the stress at the first tooth (fifth tooth 515) on the base end side.

[0135] Figure 6 It's enlarged. Figure 2 The schematic diagram shows the engagement of each tooth 51 with each blade groove 38, only showing each tooth 51.

[0136] In one embodiment of the turbine blade 24, at a cross section orthogonal to the extending direction of the plurality of teeth 51, i.e. Figure 6 In the schematic cross-section shown, when the intersection of the fourth straight line L4 and the third straight line L3, which are parallel to the blade height direction and pass through the first intersection point P1, is taken as the third intersection point P3, the distance B5 between the first intersection point P1 and the third intersection point P3 in the first tooth (fifth tooth 515) on the base end side is preferably larger than the distances B1, B2, B3, and B4 between the first intersection point P1 and the third intersection point P3 in the teeth 51 other than the first tooth (fifth tooth 515) on the base end side.

[0137] It should be noted that the distance between the first intersection point P1 and the third intersection point P3 in the first tooth 511 is B1, the distance between the first intersection point P1 and the third intersection point P3 in the second tooth 512 is B2, the distance between the first intersection point P1 and the third intersection point P3 in the third tooth 513 is B3, and the distance between the first intersection point P1 and the third intersection point P3 in the fourth tooth 514 is B4.

[0138] When subjected to centrifugal stress caused by the centrifugal load transmitted from the airfoil 44, each of the multiple teeth 51 is subjected to force from the rotor disk 35 along the blade height direction, i.e., the extension direction of the fourth straight line L4. Therefore, in each of the multiple teeth 51, the distances B1, B2, B3, B4, and B5 between the first intersection point P1 and the third intersection point P3 are closely related to the strength of the tooth 51.

[0139] According to one embodiment of the turbine blade 24, since the strength in the first tooth (fifth tooth 515) on the base end side is greater than the strength in the other teeth 51 on the base end side, the stress at the first tooth (fifth tooth 515) on the base end side can be suppressed.

[0140] In one embodiment of the turbine blade 24, the distance B5 between the first intersection point P1 and the third intersection point P3 in the first tooth (fifth tooth 515) on the base end side is preferably 101% or more and 130% or less of the distance B4 between the first intersection point P1 and the third intersection point P3 in the second tooth (fourth tooth 514) on the base end side.

[0141] As described above, increasing the strength of the tooth on the base side (fifth tooth 515) reduces the stress on that tooth (fifth tooth 515), but this has the side effect of increasing the stress at the location of the blade groove 38 (fifth blade groove 385) of the rotor disk 35 that abuts against that tooth (fifth tooth 515). As described above, by increasing the spacing I between the first tooth (fifth tooth 515) and the second tooth (fourth tooth 514) on the base side... 45 and the interval I between the second tooth (fourth tooth 514) on the base side and the third tooth (third tooth 513) on the base side. 34 The distance I between the first tooth (first tooth 511) and the second tooth (second tooth 512) on either side of the front end is... 12 Larger diameters can suppress this side effect. However, if the distance between the first tooth (fifth tooth 515) and the second tooth (fourth tooth 514) on the basal side is I... 45 and the interval I between the second tooth (fourth tooth 514) on the base side and the third tooth (third tooth 513) on the base side. 34 The distance I between the first tooth (first tooth 511) and the second tooth (second tooth 512) on either side of the front end is... 12 If the size is too large, it will cause other side effects such as increased stress at the part of the blade groove 38 that can engage with the tooth 51 on the front end side of the first tooth (fifth tooth 515) or the second tooth (fourth tooth 514) on the base end side.

[0142] The inventors, through in-depth research, determined that if the distance B5 between the first intersection point P1 and the third intersection point P3 in the first tooth (fifth tooth 515) on the base end side is more than 101% and less than 130% of the distance B4 between the first intersection point P1 and the third intersection point P3 in the second tooth (fourth tooth 514) on the base end side, then by appropriately setting the interval I between the first tooth (fifth tooth 515) and the second tooth (fourth tooth 514) on the base end side... 45 and the interval I between the second tooth (fourth tooth 514) on the base side and the third tooth (third tooth 513) on the base side. 34 It can suppress the aforementioned side effects as well as other side effects.

[0143] Therefore, it is possible to suppress the local increase of stress acting on the rotor disk 35, and to suppress the stress at the first tooth (fifth tooth 515) on the base end side.

[0144] In one embodiment of the turbine blade 24, the distance B5 between the first intersection point P1 and the third intersection point P3 in the first tooth (fifth tooth 515) on the base end side is more than 105% and less than 110% of the distance B4 between the first intersection point P1 and the third intersection point P3 in the second tooth (fourth tooth 514) on the base end side.

[0145] The inventors, through in-depth research, determined that if the distance B5 between the first intersection point P1 and the third intersection point P3 in the first tooth (fifth tooth 515) on the base end side is more than 105% and less than 110% of the distance B4 between the first intersection point P1 and the third intersection point P3 in the second tooth (fourth tooth 514) on the base end side, then by appropriately setting the interval I between the first tooth (fifth tooth 515) and the second tooth (fourth tooth 514) on the base end side... 45 and the interval 1 between the second tooth (fourth tooth 514) on the base side and the third tooth (third tooth 513) on the base side. 34 This can further suppress the other side effects mentioned above.

[0146] Therefore, it is possible to further suppress the local increase of stress acting on the rotor disk 35, and to suppress the stress at the first tooth (fifth tooth 515) on the base end side.

[0147] Figure 7 It's enlarged. Figure 2 The schematic diagram shows the engagement of each tooth 51 with each blade groove 38, only showing each tooth 51.

[0148] In one embodiment of the turbine blade 24, at a cross section orthogonal to the extending direction of the plurality of teeth 51, i.e. Figure 7 In the schematic cross-section shown, when the intersection of the fourth straight line L4, which is parallel to the blade height direction and passes through the first intersection point P1, and the fifth straight line L5, which is orthogonal to the blade height direction and passes through the second intersection point P2, is taken as the fourth intersection point P4, the distance C5 between the first intersection point P1 and the fourth intersection point P4 of the first tooth (fifth tooth 515) on the base end side is preferably larger than the distances C1, C2, C3, and C4 between the first intersection point P1 and the fourth intersection point P4 of the teeth 51 other than the first tooth (fifth tooth 515) on the base end side.

[0149] It should be noted that the distance between the first intersection point P1 and the fourth intersection point P4 in the first tooth 511 is C1, the distance between the first intersection point P1 and the fourth intersection point P4 in the second tooth 512 is C2, the distance between the first intersection point P1 and the fourth intersection point P4 in the third tooth 513 is C3, and the distance between the first intersection point P1 and the fourth intersection point P4 in the fourth tooth 514 is C4.

[0150] In each of the plurality of teeth 5, the distances C1, C2, C3, C4, and C5 between the first intersection point P1 and the fourth intersection point P4 are equivalent to the blade height components of the distances A1, A2, A3, A4, and A5 between the first intersection point P1 and the second intersection point P2. Therefore, as described above, if the distance A5 between the first intersection point P1 and the second intersection point P2 in the base-end side first tooth (fifth tooth 515) is greater than the distances A1, A2, A3, and A4 between the first intersection point P1 and the second intersection point P2 in the teeth 51 other than the base-end side first tooth (fifth tooth 515), then the distance C5 between the first intersection point P1 and the fourth intersection point P4 in the base-end side first tooth (fifth tooth 515) is greater than the distances C1, C2, C3, and C4 between the first intersection point P1 and the fourth intersection point P4 in the teeth 51 other than the base-end side first tooth (fifth tooth 515).

[0151] Therefore, the thickness of the first tooth (fifth tooth 515) on the base end side is greater than the thickness of the other teeth 51 on the base end side, thus suppressing the stress at the first tooth (fifth tooth 515) on the base end side.

[0152] In one embodiment of the turbine blade 24, the distance C5 between the first intersection point P1 and the fourth intersection point P4 in the first tooth (fifth tooth 515) on the base end side is preferably 100.5% or more and 110% or less of the distance C4 between the first intersection point P1 and the fourth intersection point P4 in the second tooth (fourth tooth 514) on the base end side.

[0153] As described above, increasing the strength of the tooth on the base side (fifth tooth 515) reduces the stress on that tooth (fifth tooth 515), but this has the side effect of increasing the stress at the location of the blade groove 38 (fifth blade groove 385) of the rotor disk 35 that abuts against that tooth (fifth tooth 515). As described above, by increasing the spacing I between the first tooth (fifth tooth 515) and the second tooth (fourth tooth 514) on the base side... 45 and the interval I between the second tooth (fourth tooth 514) on the base side and the third tooth (third tooth 513) on the base side. 34 The distance I between the first tooth (first tooth 511) and the second tooth (second tooth 512) on either side of the front end is... 12 Larger diameters can suppress this side effect. However, if the distance between the first tooth (fifth tooth 515) and the second tooth (fourth tooth 514) on the basal side is I... 45 and the interval I between the second tooth (fourth tooth 514) on the base side and the third tooth (third tooth 513) on the base side. 34 The distance I between the first tooth (first tooth 511) and the second tooth (second tooth 512) on either side of the front end is... 12If the size is too large, it will cause other side effects such as increased stress at the part of the blade groove 38 that can engage with the tooth 51 on the front end side of the first tooth (fifth tooth 515) or the second tooth (fourth tooth 514) on the base end side.

[0154] The inventors, through in-depth research, determined that if the distance C5 between the first intersection point P1 and the fourth intersection point P4 in the first tooth (fifth tooth 515) on the base end side is more than 100.5% and less than 110% of the distance C4 between the first intersection point P1 and the fourth intersection point P4 in the second tooth (fourth tooth 514) on the base end side, then by appropriately setting the interval I between the first tooth (fifth tooth 515) and the second tooth (fourth tooth 514) on the base end side... 45 and the interval I between the second tooth (fourth tooth 514) on the base side and the third tooth (third tooth 513) on the base side. 34 It can suppress the aforementioned side effects as well as other side effects.

[0155] Therefore, it is possible to suppress the local increase of stress acting on the rotor disk 35, and to suppress the stress at the first tooth (fifth tooth 515) on the base end side.

[0156] In one embodiment of the turbine blade 24, the distance C5 between the first intersection point P1 and the fourth intersection point P4 in the first tooth (fifth tooth 515) on the base end side is preferably 100.5% or more and 105% or less of the distance C4 between the first intersection point P1 and the fourth intersection point P4 in the second tooth (fourth tooth 514) on the base end side.

[0157] The inventors, through in-depth research, determined that if the distance C5 between the first intersection point P1 and the fourth intersection point P4 in the first tooth (fifth tooth 515) on the base end side is more than 100.5% and less than 105% of the distance C4 between the first intersection point P1 and the fourth intersection point P4 in the second tooth (fourth tooth 514) on the base end side, then by appropriately setting the interval 1 between the first tooth (fifth tooth 515) and the second tooth (fourth tooth 514) on the base end side... 45 and the interval I between the second tooth (fourth tooth 514) on the base side and the third tooth (third tooth 513) on the base side. 34 This can further suppress the other side effects mentioned above.

[0158] Therefore, it is possible to further suppress the local increase of stress acting on the rotor disk 35, and to suppress the stress at the first tooth (fifth tooth 515) on the base end side.

[0159] In one embodiment of the turbine blade 24, the first tooth (fifth tooth 515) on the base end side is preferably located at a cross section orthogonal to the extending direction of the plurality of teeth 51, i.e. Figures 5 to 7In the schematic cross-section shown, a straight portion 515c of the tooth tip 51a is formed on the tooth tip 51a of the first tooth (fifth tooth 515) on the base end side. The straight portion 515c of the tooth tip and the straight portion 52a of the tooth surface 515a on the front end side are preferably connected in the above cross-section by a curve 515d. The straight portion 515c of the tooth tip and the straight portion 55a of the tooth surface 55 on the base end side are preferably connected in the above cross-section by a curve 515e.

[0160] Therefore, in the above cross section, the tip 51a of the first tooth (fifth tooth 515) on the base side can be prevented from protruding unnecessarily from the other teeth 51.

[0161] In one embodiment of the turbine blade 24, the end face 50a on the base end side of the blade root 50 preferably has a bottom straight section 50b orthogonal to the blade height direction in the aforementioned cross section. The end face 50a on the base end side and the fifth intersection point P5 of the fourth straight line L4, which is parallel to the blade height direction and passes through the first intersection point P1 of the first tooth (fifth tooth 515) on the base end side, preferably exist on the bottom straight section 50b.

[0162] Therefore, in the above cross-section, compared to the case where a fifth intersection point P5 exists on the curve 515e connecting the top 51a of the first tooth (fifth tooth 515) and the bottom straight section 50b, the distance between the first intersection point P1 and the fifth intersection point P5 of the first tooth (fifth tooth 515) on the base end side is increased. Therefore, compared to the case where a fifth intersection point P5 exists on the curve 515e connecting the top 51a of the first tooth (fifth tooth 515) and the bottom straight section 50b, the thickness of the first tooth (fifth tooth 515) on the base end side can be increased.

[0163] The turbine blade assembly 90 of at least one embodiment of this disclosure (see reference) Figure 2The device includes a turbine blade 24 according to one embodiment and a rotor disk 35 having a blade groove 37 capable of engaging with the blade root 50 of the turbine blade 24. The blade groove 37 has a base-end side first blade groove (fifth blade groove 385) capable of engaging with a base-end side first tooth (fifth tooth 515), a base-end side second blade groove (fourth blade groove 384) capable of engaging with a base-end side second tooth (fourth tooth 514), a base-end side third blade groove (third blade groove 383) capable of engaging with a base-end side third tooth (third tooth 513), a front-end side first blade groove (first blade groove 381) capable of engaging with a front-end side first tooth (first tooth 511), and a front-end side second blade groove (second blade groove 382) capable of engaging with a front-end side second tooth (second tooth 512). When the tooth surface 511a of the front end side of the first tooth (first tooth 511) is in close contact with the first blade groove (first blade groove 381) on the front end side, a first gap g1 is formed at least between the tooth surface 515a of the front end side of the first tooth (fifth tooth 515) on the base end side and the first blade groove (fifth blade groove 385) on the base end side.

[0164] Since the thickness of the first tooth (fifth tooth 515) on the base end side is greater than the thickness of the other teeth 51 on the base end side, the stress at the first tooth (fifth tooth 515) on the base end side can be suppressed.

[0165] When the tooth surface 511a of the front end side of the first tooth (first tooth 511) is in close contact with the front end side first blade groove (first blade groove 381), at least the tooth surface 515a of the front end side of the first tooth (fifth tooth 515) and the base end side first blade groove (fifth blade groove 385) are formed, a first gap g1 is formed between them. Therefore, when subjected to centrifugal stress caused by the centrifugal load transmitted from the airfoil 44, the stress at the part where the base end side first blade groove (fifth blade groove 385) is formed and the stress at the base end side first tooth (fifth tooth 515) can be reduced.

[0166] Therefore, the aforementioned side effects caused by making the thickness of the first tooth (fifth tooth 515) on the base side greater than the thickness of the other teeth 51 on the base side are suppressed.

[0167] In one embodiment of the turbine blade assembly 90, when the tooth surface 511a of the front end side of the first tooth (first tooth 511) is in close contact with the first blade groove (first blade groove 381) on the front end side, a second gap g2 may be formed between the tooth surface 514a of the front end side of the second tooth (fourth tooth 514) on the base end side and the second blade groove (fourth blade groove 384) on the base end side.

[0168] This reduces the stress at the location where the second blade groove (fourth blade groove 384) is formed on the base end side, as well as the stress at the second tooth (fourth tooth 514) on the base end side.

[0169] In one embodiment of the turbine blade assembly 90, the distance A5 between the first intersection point P1 and the second intersection point P2 in the first tooth (fifth tooth 515) on the base end side is preferably more than 820 times and less than 830 times the first clearance g1.

[0170] The inventors, through in-depth research, determined that by setting the distance A5 between the first intersection point P1 and the second intersection point P2 in the first tooth (fifth tooth 515) on the base end side, and the first gap g1, in a manner where the distance A5 between the first intersection point P1 and the second intersection point P2 in the first tooth (fifth tooth 515) on the base end side is more than 820 times and less than 830 times the first gap g1, the aforementioned side effects and other side effects can be suppressed.

[0171] Therefore, it is possible to suppress the local increase of stress acting on the rotor disk 35, and to suppress the stress at the first tooth (fifth tooth 515) on the base end side.

[0172] In one embodiment of the turbine blade assembly 90, the distance B5 between the first intersection point P1 and the third intersection point P3 in the first tooth (fifth tooth 515) on the base end side is preferably more than 770 times and less than 820 times the first gap g1.

[0173] The inventors, through in-depth research, determined that by setting the distance B5 between the first intersection point P1 and the third intersection point P3 in the first tooth (fifth tooth 515) on the base end side, and the first gap g1, in a manner that the distance B5 between the first intersection point P1 and the third intersection point P3 in the first tooth (fifth tooth 515) on the base end side is more than 770 times and less than 820 times the first gap g1, the aforementioned side effects and other side effects can be suppressed.

[0174] Therefore, it is possible to suppress the local increase of stress acting on the rotor disk 35, and to suppress the stress at the first tooth (fifth tooth 515) on the base end side.

[0175] One embodiment of the gas turbine 1 includes: a plurality of turbine blades 24, each having an airfoil portion 44 and a blade root portion 50; and a rotor disk 35 having a plurality of blade slots 37 capable of engaging with the blade root portions 50. At least one of the plurality of turbine blades 24 is the turbine blade 24 of the above-described embodiment.

[0176] This improves the durability of the rotor disk 35 and the turbine blades 24.

[0177] (Repair methods for gas turbines)

[0178] The gas turbine repair method of at least one embodiment of this disclosure is a repair method for a gas turbine 1 having a plurality of turbine blades 24 and a rotor disk 35. The plurality of turbine blades 24 have airfoil portions 44 and blade roots 50, and the rotor disk 35 has a plurality of blade slots 37 capable of engaging with the blade roots 50. The gas turbine repair method of at least one embodiment of this disclosure includes a step of replacing at least one of the plurality of turbine blades mounted on the rotor disk 35 with the turbine blade 24 of the above-described embodiment.

[0179] Therefore, when repairing an existing gas turbine, by replacing at least one of the multiple turbine blades mounted on the rotor disk with the turbine blade 24 of the above-described embodiment, it is possible to suppress the local increase in stress acting on the rotor disk 35 of the existing gas turbine 1, and to suppress the stress at the first tooth (fifth tooth 515) on the base end side.

[0180] This disclosure is not limited to the above-described embodiments, but also includes modifications to the above-described embodiments, as well as appropriate combinations of these embodiments.

[0181] For example, in the turbine blade 24 of the above-described embodiment, the number of multiple teeth 51 formed at different positions in the blade height direction is 5, but it can also be 3 or 4, or even 6 or more.

[0182] It should be noted that when there are three teeth 51 formed at different positions along the blade height direction, the interval between the first tooth on the base side and the second tooth on the base side is preferably larger than the interval between the first tooth on the front side and the second tooth on the front side. Furthermore, the distance between the first intersection point P1 and the second intersection point P2 of the first tooth on the base side is preferably larger than the distance between the first intersection point and the second intersection point of any tooth other than the first tooth on the base side. It should also be noted that when there are three teeth 51 formed at different positions along the blade height direction, the second tooth on the base side and the second tooth on the front side are the same tooth.

[0183] The contents described in the above embodiments can be understood as follows, for example.

[0184] (1) The turbine blade 24 of at least one embodiment of the present disclosure includes: an airfoil portion 44; and a blade root portion 50 having a plurality of teeth 51 formed at different positions in the blade height direction. The plurality of teeth 51 includes a base-end side first tooth (fifth tooth 515), a base-end side second tooth (fourth tooth 514), and a base-end side third tooth (third tooth 513) arranged sequentially from the base end side in the blade height direction, extending in a direction intersecting the blade height direction, and a front end side first tooth (first tooth 511) and a front end side second tooth (second tooth 512) arranged sequentially from the front end side in the blade height direction, extending in the aforementioned intersecting direction. The interval I between the base-end side first tooth (fifth tooth 515) and the base-end side second tooth (fourth tooth 514) is... 45 and the interval I between the second tooth (fourth tooth 514) on the base side and the third tooth (third tooth 513) on the base side. 34 Either of them, compared to the distance I between the first tooth (first tooth 511) and the second tooth (second tooth 512) on the front end side. 12 Large. In a cross section orthogonal to the extension direction of the plurality of teeth 51, the straight line connecting the tooth bases 53 formed between adjacent teeth 51 in the blade height direction is taken as the first straight line L1. In the above cross section, the intersection of the second straight line L2, which includes the straight portion 52a of the tooth surface 52 on the front end side of each of the plurality of teeth 5, and the first straight line L1 is taken as the first intersection point P1. The intersection of the third straight line L3, which includes the straight portion 55a of the tooth surface 55 on the base end side of each of the plurality of teeth 5, and the first straight line L1 is taken as the second intersection point P2. The distance A5 between the first intersection point P1 and the second intersection point P2 in the first tooth (fifth tooth 515) on the base end side is larger than the distances A1, A2, A3, and A4 between the first intersection point P1 and the second intersection point P2 in the teeth 51 other than the first tooth (fifth tooth 515) on the base end side.

[0185] According to the structure described in (1) above, since the distance A5 between the first intersection point P1 and the second intersection point P2 in the first tooth (fifth tooth 515) on the base end side is greater than the distances A1, A2, A3, and A4 between the first intersection point P1 and the second intersection point P2 in the teeth other than the first tooth (fifth tooth 515) on the base end side, the thickness of the first tooth (fifth tooth 515) on the base end side is greater than the thickness of the teeth 51 other than the first tooth (fifth tooth 515) on the base end side. As a result, the stress at the first tooth (fifth tooth 515) on the base end side can be suppressed.

[0186] The rotor disk 35, having blade slots 37 capable of engaging with the blade root 50 of the turbine blade 24, has multiple blade slots 38 capable of engaging with multiple teeth 51 formed at different positions in the blade height direction. In the rotor disk 35, the spacing between adjacent blade slots 38 in the blade height direction (radial direction of the rotor disk 35) is the same for any two adjacent blade slots in the radial direction of the rotor disk, as is typical in a rotor disk.

[0187] Therefore, if the interval I between the first tooth (fifth tooth 515) on the base side and the second tooth (fourth tooth 514) on the base side is... 45 The distance I between the first tooth (first tooth 511) and the second tooth (second tooth 512) on the front end side. 12 If the rotational speed of the rotor disk 35 is sufficiently small, when the tooth surface 511a of the front end side of the first tooth (first tooth 511) is in close contact with the blade groove 38 (first blade groove 381) that engages with the first tooth (first tooth 511), a gap g is formed between the tooth surface 515a of the front end side of the first tooth (fifth tooth 515) and the blade groove 38 (fifth blade groove 385) that engages with the first tooth (fifth tooth 515).

[0188] Additionally, if the interval between the second tooth (fourth tooth 514) and the third tooth (third tooth 513) on the base side is 1 34 The distance I between the first tooth (first tooth 511) and the second tooth (second tooth 512) on the front end side. 12 If the rotational speed of the rotor disk 35 is sufficiently small, when the tooth surface 511a of the front end side of the first tooth (first tooth 511) is in close contact with the blade groove 38 (first blade groove 381) that engages with the first tooth (first tooth 511), a gap g is formed between the tooth surface 515a of the front end side of the first tooth (fifth tooth 515) and the blade groove 38 (fifth blade groove 385) that engages with the first tooth (fifth tooth 515), and between the tooth surface 514a of the front end side of the second tooth (fourth tooth 514) and the blade groove 38 (fourth blade groove 384) that engages with the second tooth (fourth tooth 514).

[0189] Therefore, when the turbine blade 24 of the above-described (1) structure is mounted on a rotor disk 35 having the same structure as a general rotor disk, and when the rotational speed of the rotor disk 35 is sufficiently low, when the tooth surface 511a of the front end side of the first tooth (first tooth 511) is in close contact with the blade groove 38 (first blade groove 381) for engaging the first tooth (first tooth 511), a gap g is formed between the tooth surface 515a of the front end side of the first tooth (fifth tooth 515) and the blade groove 38 (fifth blade groove 385) for engaging the first tooth (fifth tooth 515). Therefore, according to the above-described (1) structure, the gap 1 between the first tooth (fifth tooth 515) and the second tooth (fourth tooth 514) on the base end side is... 45 and the interval I between the second tooth (fourth tooth 514) on the base side and the third tooth (third tooth 513) on the base side. 34 The distance I between the first tooth (first tooth 511) and the second tooth (second tooth 512) on either side of the front end is... 12 Compared to the same case, it is possible to reduce the stress at the blade groove 38 (fifth blade groove 385) of the rotor disk 35 that abuts against the first tooth (fifth tooth 515) on the base end side when the rotor disk 35 is subjected to centrifugal stress caused by the centrifugal load transmitted from the airfoil 44, as well as the stress at the first tooth (fifth tooth 515) on the base end side.

[0190] Therefore, according to the structure described in (1) above, by making the thickness of the first tooth (fifth tooth 515) on the base end side greater than the thickness of the teeth 51 other than the first tooth (fifth tooth 515) on the base end side, stress at the first tooth (fifth tooth 515) on the base end side can be suppressed. In addition, according to the structure described in (1) above, the aforementioned side effects caused by making the thickness of the first tooth (fifth tooth 515) on the base end side greater than the thickness of the teeth 51 other than the first tooth (fifth tooth 515) on the base end side can be suppressed.

[0191] (2) In several embodiments, in the structure described in (1) above, it is preferable that the distance A5 between the first intersection point P1 and the second intersection point P2 in the first tooth (fifth tooth 515) on the base end side is more than 101% and less than 105% of the distance A4 between the first intersection point P1 and the second intersection point P2 in the second tooth (fourth tooth 514) on the base end side.

[0192] According to the structure described in (2) above, it is possible to suppress the local increase of stress acting on the rotor disk 35, and to suppress the stress at the first tooth (fifth tooth 515) on the base end side.

[0193] (3) In several embodiments, in the structure described in (2) above, it is preferable that the distance A5 between the first intersection point P1 and the second intersection point P2 in the first tooth (fifth tooth 515) on the base end side is more than 102% and less than 104% of the distance A4 between the first intersection point P1 and the second intersection point P2 in the second tooth (fourth tooth 514) on the base end side.

[0194] According to the structure described in (3) above, it is possible to further suppress the local increase of stress acting on the rotor disk 35, and to suppress the stress at the first tooth (fifth tooth 515) on the base end side.

[0195] (4) In several embodiments, in any of the structures described in (1) to (3) above, it is preferable that, in the cross section described above, when the intersection of the fourth straight line L4 and the third straight line L3, which are parallel to the blade height direction and pass through the first intersection point P1, is taken as the third intersection point P3, the distance B5 between the first intersection point P1 and the third intersection point P3 of the first tooth (fifth tooth 515) on the base end side is greater than the distances B1, B2, B3, and B4 between the first intersection point P1 and the third intersection point P3 of the teeth 51 other than the first tooth (fifth tooth 515) on the base end side.

[0196] According to the structure described above (4), the strength in the first tooth (fifth tooth 515) on the base end side is greater than the strength in the other teeth 51 on the base end side, thus suppressing the stress at the first tooth (fifth tooth 515) on the base end side.

[0197] (5) In several embodiments, in the structure of (4) above, it is preferred that the distance B5 between the first intersection point P1 and the third intersection point P3 in the first tooth (fifth tooth 515) on the base end side is more than 101% and less than 130% of the distance B4 between the first intersection point P1 and the third intersection point P3 in the second tooth (fourth tooth 514) on the base end side.

[0198] According to the structure described in (5) above, it is possible to suppress the local increase of stress acting on the rotor disk 35, and to suppress the stress at the first tooth (fifth tooth 515) on the base end side.

[0199] (6) In several embodiments, in the structure of (5) above, it is preferable that the distance B5 between the first intersection point P1 and the third intersection point P3 in the first tooth (fifth tooth 515) on the base end side is more than 105% and less than 110% of the distance B4 between the first intersection point P1 and the third intersection point P3 in the second tooth (fourth tooth 514) on the base end side.

[0200] According to the structure described in (6) above, it is possible to further suppress the local increase of stress acting on the rotor disk 35, and to suppress the stress at the first tooth (fifth tooth 515) on the base end side.

[0201] (7) In several embodiments, in any of the structures in (1) to (6) above, it is preferred that, in the above cross section, when the intersection of the fourth straight line L4, which is parallel to the blade height direction and passes through the first intersection point P1, and the fifth straight line L5, which is orthogonal to the blade height direction and passes through the second intersection point P2, is taken as the fourth intersection point P4, the distance C5 between the first intersection point P1 and the fourth intersection point P4 of the first tooth (fifth tooth 515) on the base end side is greater than the distances C1, C2, C3, and C4 between the first intersection point P1 and the fourth intersection point P4 of the teeth 51 other than the first tooth (fifth tooth 515) on the base end side.

[0202] According to the structure described above (7), since the thickness of the first tooth (fifth tooth 515) on the base end side is greater than the thickness of the other teeth 51 on the base end side (fifth tooth 515), the stress at the first tooth (fifth tooth 515) on the base end side can be suppressed.

[0203] (8) In several embodiments, in the structure of (7) above, it is preferable that the distance C5 between the first intersection point P1 and the fourth intersection point P4 in the first tooth (fifth tooth 515) on the base end side is more than 100.5% and less than 110% of the distance C4 between the first intersection point P1 and the fourth intersection point P4 in the second tooth (fourth tooth 514) on the base end side.

[0204] According to the structure described above (8), it is possible to suppress the local increase of stress acting on the rotor disk 35, and to suppress the stress at the first tooth (fifth tooth 515) on the base end side.

[0205] (9) In several embodiments, in the structure of (8) above, it is preferable that the distance C5 between the first intersection point P1 and the fourth intersection point P4 in the first tooth (fifth tooth 515) on the base end side is more than 100.5% and less than 105% of the distance C4 between the first intersection point P1 and the fourth intersection point P4 in the second tooth (fourth tooth 514) on the base end side.

[0206] According to the structure described above (9), it is possible to further suppress the local increase of stress acting on the rotor disk and to suppress the stress at the first tooth on the base end side.

[0207] (10) In several embodiments, in any of the structures described in (1) to (9) above, it is preferable that the base-end side first tooth (fifth tooth 515) has a tooth tip straight portion 515c formed on the tooth tip 51a of the base-end side first tooth (fifth tooth 515) in the cross section. Preferably, the tooth tip straight portion 515c and the straight portion 52a of the front end side tooth surface 515a are connected in the cross section by a curve 515d. Preferably, the tooth tip straight portion 515c and the straight portion 55a of the base end side tooth surface 55 are connected in the cross section by a curve 515e.

[0208] According to the structure described in (10), in the cross section described above, the tip 51a of the first tooth (fifth tooth 515) on the base side can be prevented from protruding unnecessarily from the other teeth 51.

[0209] (11) In several embodiments, in any of the structures described in (1) to (10) above, it is preferable that the end face 50a on the base end side of the blade root 50 has a bottom straight section 50b orthogonal to the blade height direction in the cross section described above. Preferably, the end face 50a on the base end side and the fifth intersection point P5 of the fourth straight line L4, which is parallel to the blade height direction and passes through the first intersection point P1 of the first tooth (fifth tooth 515) on the base end side, exist on the bottom straight section 50b.

[0210] According to the structure described in (11), in the cross-section described above, compared to the case where a fifth intersection point P5 exists on the curve 515e connecting the top 51a of the first tooth (fifth tooth 515) on the base end side and the bottom straight section 50b, the distance between the first intersection point P1 and the fifth intersection point P5 of the first tooth (fifth tooth 515) on the base end side increases. Therefore, compared to the case where a fifth intersection point P5 exists on the curve 515e connecting the top 51a of the first tooth (fifth tooth 515) on the base end side and the bottom straight section 50b, the thickness of the first tooth (fifth tooth 515) on the base end side can be increased.

[0211] (12) The turbine blade assembly 90 of at least one embodiment of the present disclosure includes: a turbine blade 24 with any of the structures described in (1) to (11) above; and a rotor disk 35 having a blade groove 37 capable of engaging with the blade root 50 of the turbine blade 24. The blade groove 37 has a base-end side first blade groove (fifth blade groove 385) capable of engaging with a base-end side first tooth (fifth tooth 515), a base-end side second blade groove (fourth blade groove 384) capable of engaging with a base-end side second tooth (fourth tooth 514), a base-end side third blade groove (third blade groove 383) capable of engaging with a base-end side third tooth (third tooth 513), a front-end side first blade groove (first blade groove 381) capable of engaging with a front-end side first tooth (first tooth 511), and a front-end side second blade groove (second blade groove 382) capable of engaging with a front-end side second tooth (second tooth 512). When the tooth surface 511a of the front end side of the first tooth (first tooth 511) is in close contact with the first blade groove (first blade groove 381) on the front end side, a first gap g1 is formed at least between the tooth surface 515a of the front end side of the first tooth (fifth tooth 515) on the base end side and the first blade groove (fifth blade groove 385) on the base end side.

[0212] According to the structure described in (12), since the turbine blade 24 has any of the structures described in (1) to (11), the thickness of the first tooth (fifth tooth 515) on the base end side is greater than the thickness of the other teeth 51 on the base end side. As a result, the stress at the first tooth (fifth tooth 515) on the base end side can be suppressed.

[0213] According to the structure described above (12), when the tooth surface 511a of the front end side of the first tooth (first tooth 511) is in close contact with the first blade groove (first blade groove 381) on the front end side, a first gap g1 is formed at least between the tooth surface 515a of the front end side of the first tooth (fifth tooth 515) on the base end side and the first blade groove (fifth blade groove 385) on the base end side. Therefore, the stress at the part of the first blade groove (fifth blade groove 385) on the base end side and the stress at the first tooth (fifth tooth 515) on the base end side can be reduced when subjected to centrifugal stress caused by centrifugal load transmitted from the airfoil 44.

[0214] Therefore, according to the structure described above (12), the aforementioned side effects caused by making the thickness of the first tooth (fifth tooth 515) on the base side greater than the thickness of the teeth 51 other than the first tooth (fifth tooth 515) on the base side can be suppressed.

[0215] (13) In several embodiments, in the structure described in (12) above, it is preferable that when the tooth surface 511a of the front end side of the first tooth (first tooth 511) is in close contact with the first blade groove (first blade groove 381) on the front end side, a second gap g2 is formed between the tooth surface 514a of the front end side of the second tooth (fourth tooth 514) on the base end side and the second blade groove (fourth blade groove 384) on the base end side.

[0216] According to the structure described above (13), the stress at the location where the second blade groove (fourth blade groove 384) is formed on the base end side and the stress at the second tooth (fourth tooth 514) on the base end side can be reduced when subjected to centrifugal stress caused by centrifugal load transmitted from the airfoil 44.

[0217] (14) In several embodiments, in the structure of (12) or (13) above, it is preferred that the distance A5 between the first intersection point P1 and the second intersection point P2 in the first tooth (fifth tooth 515) on the base end side is more than 820 times and less than 830 times the first gap g1.

[0218] The inventors, through in-depth research, determined that by setting the distance A5 between the first intersection point P1 and the second intersection point P2 in the first tooth (fifth tooth 515) on the base end side, and the first gap g1, in a manner where the distance A5 between the first intersection point P1 and the second intersection point P2 in the first tooth (fifth tooth 515) on the base end side is more than 820 times and less than 830 times the first gap g1, the aforementioned side effects and other side effects can be suppressed.

[0219] According to the structure described above (14), it is possible to suppress the local increase of stress acting on the rotor disk 35, and to suppress the stress at the first tooth (fifth tooth 515) on the base end side.

[0220] (15) The gas turbine 1 of at least one embodiment of the present disclosure includes: a plurality of turbine blades 24 having airfoil portions 44 and blade roots 50; and a rotor disk 35 having a plurality of blade slots 37 capable of engaging with the blade roots 50. At least one of the plurality of turbine blades 24 is a turbine blade 24 with any of the structures described in (1) to (11) above.

[0221] According to the structure described above (15), the durability of the rotor disk 35 and the turbine blade 24 can be improved.

[0222] (16) A repair method for a gas turbine 1 according to at least one embodiment of the present disclosure, the gas turbine comprising: a plurality of turbine blades 24 having airfoil portions 44 and blade roots 50; and a rotor disk 35 having a plurality of blade slots 37 capable of engaging with the blade roots 50, the repair method for the gas turbine 1 comprising a step of replacing at least one of the plurality of turbine blades mounted on the rotor disk 35 with a turbine blade 24 of any of the structures described in (1) to (11) above.

[0223] According to the method described in (16) above, when repairing an existing gas turbine, by replacing at least one of the multiple turbine blades mounted on the rotor disk with a turbine blade 24 of any of the structures described in (1) to (11) above, it is possible to suppress the local increase in stress on the rotor disk 35 of the existing gas turbine 1, and to suppress the stress at the first tooth (fifth tooth 515) on the base end side.

Claims

1. A turbine blade, wherein the turbine blade has: a wing portion; and a blade root portion having a plurality of teeth formed at different positions in a blade height direction, the plurality of teeth include a first base end side tooth, a second base end side tooth, and a third base end side tooth, which extend in a direction intersecting the blade height direction and are arranged in order from a most base end side in the blade height direction, and a first tip end side tooth and a second tip end side tooth, which extend in the intersecting direction and are arranged in order from a most tip end side in the blade height direction, either one of a distance between a tooth surface of the tip end side in the first base end side tooth and a tooth surface of the tip end side in the second base end side tooth, and a distance between the tooth surface of the tip end side in the second base end side tooth and a tooth surface of the tip end side in the third base end side tooth, is larger than a distance between the tooth surface of the tip end side in the first tip end side tooth and the tooth surface of the tip end side in the second tip end side tooth, in a cross section orthogonal to an extending direction of the plurality of teeth, a straight line connecting tooth bottom portions formed between teeth adjacent in the blade height direction to each other is a first straight line, in the cross section, when an intersection of a second straight line including a straight line portion of the tooth surface of the tip end side in each of the plurality of teeth and the first straight line is a first intersection, and an intersection of a third straight line including a straight line portion of the tooth surface of the base end side in each of the plurality of teeth and the first straight line is a second intersection, a distance between the first intersection and the second intersection in the first base end side tooth is larger than a distance between the first intersection and the second intersection in the tooth other than the first base end side tooth.

2. The turbine blade according to claim 1, wherein the distance between the first intersection and the second intersection in the first base end side tooth is 101% or more and 105% or less of the distance between the first intersection and the second intersection in the second base end side tooth.

3. The turbine blade according to claim 2, wherein the distance between the first intersection and the second intersection in the first base end side tooth is 102% or more and 104% or less of the distance between the first intersection and the second intersection in the second base end side tooth.

4. The turbine blade according to any one of claims 1 to 3, wherein in the cross section, when an intersection of a fourth straight line parallel to the blade height direction and passing through the first intersection and the third straight line is a third intersection, the distance between the first intersection and the third intersection in the first base end side tooth is larger than the distance between the first intersection and the third intersection in the tooth other than the first base end side tooth.

5. The turbine blade according to claim 4, wherein the distance between the first intersection and the third intersection in the first base end side tooth is 101% or more and 130% or less of the distance between the first intersection and the third intersection in the second base end side tooth.

6. The turbine blade according to claim 5, wherein The distance between the first intersection point and the third intersection point in the base end side first tooth is 105% or more and 110% or less of the distance between the first intersection point and the third intersection point in the base end side second tooth.

7. The turbine rotor blade according to any one of claims 1 to 3, wherein In the cross section, when an intersection point of a fourth straight line that is parallel to the blade height direction and passes through the first intersection point in each of the plurality of teeth and a fifth straight line that is orthogonal to the blade height direction and passes through the second intersection point is taken as a fourth intersection point, The distance between the first intersection point and the fourth intersection point in the base end side first tooth is larger than the distance between the first intersection point and the fourth intersection point in the tooth other than the base end side first tooth.

8. The turbine rotor blade according to claim 7, wherein The distance between the first intersection point and the fourth intersection point in the base end side first tooth is 100.5% or more and 110% or less of the distance between the first intersection point and the fourth intersection point in the base end side second tooth.

9. The turbine rotor blade according to claim 8, wherein The distance between the first intersection point and the fourth intersection point in the base end side first tooth is 100.5% or more and 105% or less of the distance between the first intersection point and the fourth intersection point in the base end side second tooth.

10. The turbine rotor blade according to any one of claims 1 to 3, wherein The base end side first tooth has a tooth top linear portion formed at a tooth top portion of the base end side first tooth in the cross section, The tooth top linear portion and the linear portion of the front end side tooth surface are connected by a curved line in the cross section, The tooth top linear portion and the linear portion of the base end side tooth surface are connected by a curved line in the cross section.

11. The turbine rotor blade according to any one of claims 1 to 3, wherein The base end side end surface of the blade root has a bottom linear portion orthogonal to the blade height direction in the cross section, A fifth intersection point of the base end side end surface and a fourth straight line that is parallel to the blade height direction and passes through the first intersection point of the base end side first tooth exists on the bottom linear portion.

12. A turbine rotor blade assembly, wherein The turbine rotor blade assembly includes: The turbine rotor blade according to any one of claims 1 to 3; and A rotor disk having a blade groove portion capable of engaging with the blade root of the turbine rotor blade, The blade groove portion has a base end side first blade groove capable of engaging with the base end side first tooth, a base end side second blade groove capable of engaging with the base end side second tooth, a base end side third blade groove capable of engaging with the base end side third tooth, a front end side first blade groove capable of engaging with the front end side first tooth, and a front end side second blade groove capable of engaging with the front end side second tooth, When the front end side tooth surface of the front end side first tooth is brought into close contact with the front end side first blade groove, a first gap is formed at least between the front end side tooth surface of the base end side first tooth and the base end side first blade groove.

13. The turbine rotor blade assembly according to claim 12, wherein A second gap is formed between the tooth surface on the tip side of the base end side second tooth and the base end side second blade slot when the tooth surface on the tip side of the tip side first tooth is in close contact with the tip side first blade slot.

14. The turbine blade assembly of claim 12, wherein, The distance between the first intersection and the second intersection in the base end side first tooth is 820 times or more and 830 times or less of the first gap.

15. A gas turbine, wherein, The gas turbine comprises: A plurality of turbine blades having an airfoil portion and a blade root portion; and A rotor disk having a plurality of blade slot portions capable of engaging with the blade root portions, At least one of the plurality of turbine blades is the turbine blade according to any one of claims 1 to 3.

16. A repair method of a gas turbine comprising: a plurality of turbine blades having an airfoil portion and a blade root portion; and a rotor disk having a plurality of blade slot portions capable of engaging with the blade root portions, wherein, The repair method of the gas turbine includes a step of replacing at least one of the plurality of turbine blades mounted to the rotor disk with the turbine blade according to any one of claims 1 to 3.

Images