turbine

Abstract

To obtain a high attenuation effect relative to vibration of a blade.SOLUTION: A turbine includes a rotor and a plurality of turbine blades arranged along a circumferential direction of the rotor. The plurality of turbine blades each include: a first turbine blade including a first moving blade and a first shroud disposed in a tip portion of the first moving blade; and a second turbine blade including a second moving blade arranged adjacent to one side in the circumferential direction of the rotor relative to the first moving blade, and a second shroud disposed in a tip portion of the second moving blade. In an overlapping region in which at least a part of one-side lateral face at one side in the circumferential direction of the first shroud overlaps at least a part of the other-side lateral face at the other side in the circumferential direction of the second shroud in the circumferential direction, the one-side lateral face is positioned on a radially outer side relative to the other-side lateral face and the second shroud is heavier than the first shroud.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to turbines. [Background technology]

[0002] Turbines such as steam turbines and gas turbines have adopted several countermeasures to suppress blade vibration during operation. For example, Patent Document 1 discloses a configuration in which a shroud is provided for each of a plurality of blades, and adjacent shrouds are separated from each other and have pin engagement holes into which pins are inserted so as to have backlash. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-285931 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the technology described in Patent Document 1 suppresses vibration of the blade by sliding the pin into the pin engagement hole, and since the sliding contact area of ​​the pin is limited, the damping effect of suppressing blade vibration is small.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a turbine that can achieve a high damping effect against blade vibration. [Means for solving the problem]

[0006] In order to achieve the above object, the turbine of the present disclosure comprises a rotor and a plurality of turbine blades arranged circumferentially of the rotor, the plurality of turbine blades including a first turbine blade including a first rotor blade and a first shroud provided at a tip of the first rotor blade, and a second turbine blade including a second rotor blade arranged adjacent to the first rotor blade on one side of the rotor in the circumferential direction and a second shroud provided at a tip of the second rotor blade, wherein at least a portion of a one-side side surface on one side of the circumferential direction of the first shroud and at least a portion of a other-side side surface on the other side of the circumferential direction of the second shroud overlap in the circumferential direction, the one-side side surface is located radially outward from the other-side side surface, and the second shroud is heavier than the first shroud. [Effects of the Invention]

[0007] According to the turbine of the present disclosure, a high damping effect can be obtained against blade vibration. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic diagram illustrating an example gas turbine configuration including a turbine according to some embodiments. [Figure 2] FIG. 1 is a diagram schematically illustrating a configuration of a turbine according to a first embodiment. [Figure 3] 3A to 3C are diagrams for explaining an example of a method for forming a turbine according to the first embodiment. [Figure 4] 3 is an enlarged view of the periphery of one side surface of the first shroud shown in FIG. 2. [Figure 5] 3 is an enlarged view of the periphery of one side surface of the second shroud shown in FIG. 2. FIG. [Figure 6] FIG. 10 is an enlarged view of the periphery of one side surface of a first shroud according to a second embodiment. [Figure 7] FIG. 10 is a diagram schematically showing the internal configuration of a first rotor blade and the internal configuration of a second rotor blade according to a third embodiment. [Figure 8] FIG. 10 is a diagram schematically showing the configuration of a turbine according to a fourth embodiment. [Figure 9] FIG. 10 is a diagram schematically showing the internal configuration of a fourth rotor blade and the internal configuration of a fifth rotor blade according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, a turbine according to an embodiment of the present disclosure will be described with reference to the drawings. The embodiment shows one aspect of the present disclosure, but does not limit the present disclosure and can be modified as desired within the scope of the technical concept of the present disclosure.

[0010] (Gas Turbine) Fig. 1 is a diagram schematically illustrating an example configuration of a gas turbine 100 including a turbine 1 according to some embodiments. As illustrated in Fig. 1, the gas turbine 100 includes a compressor 102 for generating compressed air G2, a combustor 104 for generating combustion gas G3 using the compressed air G2 and fuel, and a turbine 1 configured to be rotationally driven by the combustion gas G3. The gas turbine 100 is applied, for example, as an aircraft engine for obtaining propulsion power for an aircraft. Note that the gas turbine 100 may also be used for other purposes, such as power generation.

[0011] The compressor 102 includes a compressor rotor 106 , a compressor casing 108 , a plurality of rows of compressor stator vanes 110 , and a plurality of rows of compressor rotor blades 112 .

[0012] The compressor rotor 106 is configured to be rotatable about an axis O. The compressor rotor 106 has a rod shape, and its longitudinal direction is along an axial direction D1 in which the axis O extends. The compressor casing 108 has a cylindrical shape, and covers the compressor rotor 106 from the outside in the radial direction of the compressor rotor 106.

[0013] The multiple compressor stator vane rows 110 are fixed to the compressor casing 108 at intervals along the axial direction D1. Each of the multiple compressor stator vane rows 110 includes multiple compressor stator vanes 111 arranged on the inner circumferential surface of the compressor casing 108 at intervals along the circumferential direction of the compressor rotor 106.

[0014] The multiple compressor rotor blade rows 112 are implanted in the compressor rotor 106 at intervals from one another along the axial direction D1 so as to be arranged alternately with respect to the compressor stator blade rows 110. Each of the multiple compressor rotor blade rows 112 includes multiple compressor rotor blades 113 arranged at intervals from one another along the circumferential direction of the compressor rotor 106 on the outer circumferential surface of the compressor rotor 106.

[0015] 1 is formed with an air intake 114 for taking in air G1 from the outside. The air G1 taken into the compressor 102 passes through a plurality of compressor stator blade rows 110 and a plurality of compressor rotor blade rows 112 and is compressed to become high-temperature, high-pressure compressed air G2.

[0016] The combustor 104 is supplied with fuel and compressed air G2 generated by the compressor 102, and generates combustion gas G3, which is a working fluid of the turbine 1, by mixing and burning the fuel and compressed air G2. In the embodiment illustrated in FIG. 1 , the gas turbine 100 includes a combustor casing 116 disposed between the compressor casing 108 and a turbine casing 6, which will be described later, in the axial direction D1. A plurality of combustors 104 are disposed in the combustor casing 116.

[0017] The turbine 1 includes a turbine rotor 3, a turbine casing 6, a plurality of turbine stator blade rows 8, and a plurality of turbine rotor blade rows 10.

[0018] The turbine rotor 3 is configured to be rotatable about an axis O. The turbine rotor 3 has a rod shape, and its longitudinal direction is along an axial direction D1. In the embodiment illustrated in FIG. 1, the turbine rotor 3 and a compressor rotor 106 are integrally connected in the axial direction D1. In other words, the gas turbine 100 includes a gas turbine rotor 101 that is configured from the turbine rotor 3 and the compressor rotor 106.

[0019] Hereinafter, the radial direction of the turbine rotor 3 will be simply referred to as the "radial direction D2," and the circumferential direction of the turbine rotor 3 will be simply referred to as the "circumferential direction D3." The radial direction D2 is perpendicular to the axis O. The direction of the radial direction D2 that approaches the axis O is referred to as the direction toward the inside of the radial direction D2, and the direction that moves away from the axis O is referred to as the direction toward the outside of the radial direction D2.

[0020] The turbine casing 6 has a cylindrical shape and covers the turbine rotor 3 from the outside in the radial direction D2.

[0021] The plurality of turbine stator blade rows 8 are fixed to the turbine casing 6 at intervals along the axial direction D1. Each of the plurality of turbine stator blade rows 8 includes a plurality of turbine stator blades 12 arranged on the inner circumferential surface of the turbine casing 6 at intervals along the circumferential direction D3.

[0022] The plurality of turbine blade rows 10 are implanted in the turbine rotor 3 at intervals from one another along the axial direction D1 so as to be arranged alternately with respect to the turbine stator blade rows 8. Each of the plurality of turbine blade rows 10 includes a plurality of turbine blades 2 arranged on the outer circumferential surface of the turbine rotor 3 along the circumferential direction D3.

[0023] 1 is supplied with combustion gas G3 generated in a combustor 104, and this combustion gas G3 passes through a plurality of turbine stator vane rows 8 and a plurality of turbine rotor blade rows 10, thereby rotating and driving a turbine rotor 3. The rotational force of the turbine 1 is transmitted to the compressor 102 via the turbine rotor 3, and the compressor 102 compresses air G1 flowing through the compressor 102. The turbine 1 exhausts the combustion gas G3 (exhaust gas G4) that has passed through the plurality of turbine stator vane rows 8 and a plurality of turbine rotor blade rows 10, as propulsion force for the aircraft.

[0024] Although not shown, in some embodiments, the gas turbine 100 further includes a fan disposed on the opposite side of the compressor 102 from the turbine 1 in the axial direction D1 in order to increase the amount of air G1 taken into the compressor 102. The fan is connected to the turbine rotor 3 via the compressor rotor 106, and is rotationally driven by the rotational force of the turbine 1.

[0025] A specific configuration of the turbine 1 according to the present disclosure will be described below.

[0026] First Embodiment (composition) Fig. 2 is a diagram that schematically shows the configuration of the turbine 1 according to the first embodiment. Fig. 2 shows a schematic view of a part of the turbine rotor blade row 10 of Fig. 1 as viewed from the axial direction D1.

[0027] In the first embodiment, as illustrated in Fig. 2, the turbine 1 includes a rotor disk 14 fixed to the turbine rotor 3. The rotor disk 14 is fixed to the turbine rotor 3, for example, by being fitted into a hole formed in the outer circumferential surface of the turbine rotor 3. In some embodiments, the rotor disk 14 is fixed to the turbine rotor 3 by a fastener such as a bolt.

[0028] In the first embodiment, as illustrated in FIG. 2, the rotor disk 14 includes a radially extending portion 16 that is connected to the turbine rotor 3 and extends outward from the turbine rotor 3 in the radial direction D2, and a plate-shaped circumferentially extending portion 18 that extends from the tip of the radially extending portion 16 to both sides in the circumferential direction D3.

[0029] The plurality of turbine rotor blades 2 include a first turbine rotor blade 2A(2), a second turbine rotor blade 2B(2), and a third turbine rotor blade 2C(2).

[0030] The first turbine rotor blade 2A includes a first rotor blade 20 and a first shroud 24 provided at a tip 22 of the first rotor blade 20. The first rotor blade 20 is attached to the outer peripheral surface of the circumferentially extending portion 18 and extends outward in the radial direction D2 from the outer peripheral surface of the circumferentially extending portion 18. The first shroud 24 has a plate shape and extends from the tip 22 of the first rotor blade 20 to both sides in the circumferential direction D3.

[0031] In the first embodiment, the one-side side surface 24a on one side of the first shroud 24 in the circumferential direction D3 has an outer end e1 on the outside in the radial direction D2 located closer to one side in the circumferential direction D3 than an inner end e2 on the inside in the radial direction D2. The other-side side surface 24b on the other side of the first shroud 24 in the circumferential direction D3 has an outer end e3 on the outside in the radial direction D2 located closer to the other side in the circumferential direction D3 than an inner end e4 on the inside in the radial direction D2. The one-side side surface 24a and the other-side side surface 24b of the first shroud 24 each face toward the rotor disk 14 (inside) in the radial direction D2. The first shroud 24 has a symmetrical shape when viewed in the axial direction D1. The tip portion 22 of the first rotor blade 20 is located in the center of the first shroud 24 in the circumferential direction D3.

[0032] The second turbine rotor blade 2B includes a second rotor blade 40 and a second shroud 44 provided at a tip 42 of the second rotor blade 40. The second rotor blade 40 is disposed adjacent to the first rotor blade 20 on one side in the circumferential direction D3. A space through which combustion gas G3 flows is formed between the first rotor blade 20 and the second rotor blade 40 in the circumferential direction D3. The second rotor blade 40 is attached to the outer peripheral surface of the circumferential extension portion 18 and extends outward in the radial direction D2 from the outer peripheral surface of the circumferential extension portion 18. The second shroud 44 has a plate shape and extends from the tip 42 of the second rotor blade 40 to both sides in the circumferential direction D3.

[0033] In the first embodiment, the one-side side surface 44a on one side of the second shroud 44 in the circumferential direction D3 has an outer end e5 on the outside in the radial direction D2 located closer to the other side in the circumferential direction D3 than an inner end e6 on the inside in the radial direction D2. The other-side side surface 44b on the other side of the second shroud 44 in the circumferential direction D3 has an outer end e7 on the outside in the radial direction D2 located closer to the one side in the circumferential direction D3 than an inner end e8 on the inside in the radial direction D2. The one-side side surface 44a and the other-side side surface 44b of the second shroud 44 each face away from the rotor disk 14 (outside) in the radial direction D2. The second shroud 44 has a symmetrical shape when viewed in the axial direction D1. The tip 42 of the second rotor blade 40 is located in the center of the second shroud 44 in the circumferential direction D3.

[0034] The third turbine rotor blade 2C includes a third rotor blade 60 and a third shroud 64 provided at a tip 62 of the third rotor blade 60. The third rotor blade 60 is disposed adjacent to the second rotor blade 40 on one side in the circumferential direction D3. A space through which combustion gas G3 flows is formed between the second rotor blade 40 and the third rotor blade 60 in the circumferential direction D3. The third rotor blade 60 is attached to the outer peripheral surface of the circumferential extension portion 18 and extends outward in the radial direction D2 from the outer peripheral surface of the circumferential extension portion 18. The third shroud 64 has a plate shape and extends from the tip 62 of the third rotor blade 60 to both sides in the circumferential direction D3.

[0035] In the first embodiment, the one-side side surface 64a on one side of the third shroud 64 in the circumferential direction D3 has an outer end e9 on the outside in the radial direction D2 located closer to one side in the circumferential direction D3 than an inner end e10 on the inside in the radial direction D2. The other-side side surface 64b on the other side of the third shroud 64 in the circumferential direction D3 has an outer end e11 on the outside in the radial direction D2 located closer to the other side in the circumferential direction D3 than an inner end e12 on the inside in the radial direction D2. The one-side side surface 64a and the other-side side surface 64b of the third shroud 64 each face toward the rotor disk 14 (inside) in the radial direction D2. The third shroud 64 has a symmetrical shape when viewed in the axial direction D1. The tip portion 62 of the third rotor blade 60 is located in the center of the third shroud 64 in the circumferential direction D3.

[0036] In the first embodiment, the first rotor blade 20, the second rotor blade 40, and the third rotor blade 60 are configured to have the same shape as each other. Furthermore, the first rotor blade 20, the second rotor blade 40, and the third rotor blade 60 are configured from the same material.

[0037] An example of a method for forming the one side surface 24a of the first shroud 24, the other side surface 44b of the second shroud 44, the one side surface 44a of the second shroud 44, and the other side surface 64b of the third shroud 64 according to the first embodiment will be described. Fig. 3 is a diagram for explaining an example of a method for forming the turbine 1 according to the first embodiment.

[0038] In the first embodiment, the turbine 1 employs a blisk structure in which the first turbine rotor blade 2A, the second turbine rotor blade 2B, the third turbine rotor blade 2C, and the rotor disk 14 are integrally formed by, for example, casting. In this case, as illustrated in Fig. 3, the first shroud 24, the second shroud 44, and the third shroud 64 are integrally formed as a single part (integral shroud 70).

[0039] Each of the one side surface 24a of the first shroud 24 and the other side surface 44b of the second shroud 44 is formed by a first cut surface 72 obtained by cutting the one-piece shroud 70 along a first cutting line C1. As a result of this cutting, a gap may be formed between the one side surface 24a of the first shroud 24 and the other side surface 44b of the second shroud 44, or the one side surface 24a of the first shroud 24 and the other side surface 44b of the second shroud 44 may be in contact with each other.

[0040] The first cutting line C1 extends linearly and passes between a portion of the integral shroud 70 where the tip 22 of the first rotor blade 20 is connected (the center of the first shroud 24) and a portion of the integral shroud 70 where the tip 42 of the second rotor blade 40 is connected (the center of the second shroud 44). The first cutting line C1 is closer to the center of the first shroud 24 in the circumferential direction D3 than to the center of the second shroud 44. In other words, the length of the first shroud 24 in the circumferential direction D3 is shorter than the length of the second shroud 44 in the circumferential direction D3. Therefore, the second shroud 44 has a larger volume than the first shroud 24 and is heavier than the first shroud 24.

[0041] Each of the one side surface 44a of the second shroud 44 and the other side surface 64b of the third shroud 64 has a second cut surface 74 formed by cutting the one-piece shroud 70 along the second cutting line C2. As a result of this cutting, a gap may be formed between the one side surface 44a of the second shroud 44 and the other side surface 64b of the third shroud 64, or the one side surface 44a of the second shroud 44 and the other side surface 64b of the third shroud 64 may be in contact with each other.

[0042] The second cutting line C2 extends linearly and passes between a portion of the integral shroud 70 where the tip end 42 of the second rotor blade 40 is connected (the center portion of the second shroud 44) ​​and a portion of the integral shroud 70 where the tip end 62 of the third rotor blade 60 is connected (the center portion of the third shroud 64). The second cutting line C2 is closer to the center portion of the third shroud 64 in the circumferential direction D3 than to the center portion of the second shroud 44. In other words, the length of the third shroud 64 in the circumferential direction D3 is shorter than the length of the second shroud 44 in the circumferential direction D3. Therefore, the second shroud 44 has a larger volume than the third shroud 64 and is heavier than the third shroud 64.

[0043] The other side surface 24b of the first shroud 24 and the one side surface 64a of the third shroud 64 may be formed by cutting the one-piece shroud 70. In this case, the one-piece shroud 70 extends further in the circumferential direction D3 than the formed portion of the other side surface 24b of the first shroud 24, and extends further in the circumferential direction D3 than the one side surface 64a of the third shroud 64. In some embodiments, the other side surface 24b of the first shroud 24 and the other side surface 64b of the third shroud 64 may be formed simultaneously with the production (casting) of the one-piece shroud 70.

[0044] Fig. 4 is an enlarged view of the periphery of one side surface 24a of the first shroud 24 shown in Fig. 2. Fig. 5 is an enlarged view of the periphery of one side surface 44a of the second shroud 44 shown in Fig. 2.

[0045] In the first embodiment, as illustrated in FIG. 4, one side surface 24a of the first shroud 24 and the other side surface 44b of the second shroud 44 each have a planar shape that is entirely flat.

[0046] A first overlap region R1 is a region where a portion 24a1 of the one side surface 24a of the first shroud 24 and a portion 44b1 of the other side surface 44b of the second shroud 44 overlap with each other in the circumferential direction D3. As illustrated in Fig. 4, in the first overlap region R1, the one side surface 24a of the first shroud 24 is located outward in the radial direction D2 from the other side surface 44b of the second shroud 44.

[0047] In the first embodiment, as illustrated in FIG. 5, each of one side surface 44a of the second shroud 44 and the other side surface 64b of the third shroud 64 has a planar shape that is entirely flat.

[0048] A second overlap region R2 is a region where a portion 44a1 of the one side surface 44a of the second shroud 44 and a portion 64b1 of the other side surface 64b of the third shroud 64 overlap with each other in the circumferential direction D3. As illustrated in Fig. 5, in the second overlap region R2, the one side surface 44a of the second shroud 44 is located outward in the radial direction D2 from the other side surface 64b of the third shroud 64.

[0049] (Actions and Effects) The operation and effect of the turbine 1 according to the first embodiment will be described. According to the first embodiment, the second shroud 44 is heavier than the first shroud 24, and therefore, during operation of the turbine 1, the centrifugal force acting on the second rotor blades 40 is greater than the centrifugal force acting on the first rotor blades 20. As a result, the second rotor blades 40 extend longer in the radial direction D2 than the first rotor blades 20. In the first overlap region R1, the one-side side surface 24a of the first shroud 24 is positioned outward in the radial direction D2 from the other-side side surface 44b of the second shroud 44, and therefore a portion 44b1 of the other-side side surface of the second shroud 44 comes into contact with or presses against a portion 24a1 of the one-side side surface 24a of the first shroud 24. Therefore, when one or both of the first turbine rotor blade 2A and the second turbine rotor blade 2B vibrate, a portion 44b1 of the other side surface 44b of the second shroud 44 slides against a portion 24a1 of the one side surface 24a of the first shroud 24, thereby achieving a high damping effect due to friction.

[0050] According to the first embodiment, the first shroud 24 and the second shroud 44 have different shapes, and therefore the static deformation characteristics of the first turbine rotor blade 2A and the second turbine rotor blade 2B during operation of the turbine 1 are different from each other. As a result, the natural frequencies of the first turbine rotor blade 2A and the second turbine rotor blade 2B are non-uniform, and a so-called mistuned structure can be adopted for the turbine 1, thereby suppressing vibration of the turbine 1.

[0051] According to the first embodiment, the second shroud 44 is heavier than the third shroud 64, and therefore, during operation of the turbine 1, the centrifugal force acting on the second rotor blade 40 is greater than the centrifugal force acting on the third rotor blade 60. For this reason, the second rotor blade 40 extends longer in the radial direction D2 than the third rotor blade 60. In the second overlap region R2, the other side surface 64b of the third shroud 64 is located outward in the radial direction D2 from the one side surface 44a of the second shroud 44, and therefore a portion 44a1 of the one side surface 44a of the second shroud 44 comes into contact with or presses a portion 64b1 of the other side surface 64b of the third shroud 64. Therefore, when one or both of the second turbine rotor blades 2B and the third turbine rotor blades 2C vibrate, a portion 44a1 of one side surface 44a of the second shroud 44 slides against a portion 64b1 of the other side surface 64b of the third shroud 64, thereby achieving a high damping effect due to friction.

[0052] According to the first embodiment, the one side surface 24a of the first shroud 24 and the other side surface 44b of the second shroud 44 can be simultaneously formed by simply cutting the one-piece shroud 70 along the first cutting line C1. Similarly, the one side surface 44a of the second shroud 44 and the other side surface 64b of the third shroud 64 can be simultaneously formed by simply cutting the one-piece shroud 70 along the second cutting line C2. This reduces the amount of work required to process the turbine 1 compared to when separate parts (pins) are required, as described in Patent Document 1. Furthermore, since the sliding area can be increased compared to Patent Document 1, in which pins slide in pin engagement holes, a greater damping effect can be achieved than in Patent Document 1.

[0053] In the first embodiment, the number of turbine rotor blades 2 is three, but the present disclosure is not limited to this. The turbine 1 may include two turbine rotor blades 2, or four or more turbine rotor blades 2.

[0054] In the first embodiment, the first turbine rotor blade 2A, the second turbine rotor blade 2B, and the third turbine rotor blade 2C are attached to a common rotor disk 14, but the present disclosure is not limited to this. The rotor disk 14 to which the first turbine rotor blade 2A is attached and the rotor disk 14 to which the second turbine rotor blade 2B is attached may be separate bodies. The rotor disk 14 to which the second turbine rotor blade 2B is attached and the rotor disk 14 to which the third turbine rotor blade 2C is attached may be separate bodies.

[0055] In the first embodiment, the turbine 1 has been described as having a blisk structure in which the turbine rotor blades 2 and the rotor disk 14 are integrally formed, but the present disclosure is not limited to this. The turbine rotor blades 2 and the rotor disk 14 may be formed separately.

[0056] In the first embodiment, the first shroud 24, the second shroud 44, and the third shroud each have a symmetrical shape when viewed in the axial direction D1, but the present disclosure is not limited to this. Any one of the first shroud 24, the second shroud 44, and the third shroud may have an asymmetrical shape when viewed in the axial direction D1.

[0057] In the first embodiment, a portion 24a1 of the one-side side surface 24a of the first shroud and a portion 44b1 of the other-side side surface 44b of the second shroud overlap each other in the first overlap region R1, but the present disclosure is not limited to this. In some embodiments, the entire one-side side surface 24a of the first shroud and the entire other-side side surface 44b of the second shroud overlap each other in the first overlap region R1. In some embodiments, the portion 24a1 of the one-side side surface 24a of the first shroud and the entire other-side side surface 44b of the second shroud overlap each other in the first overlap region R1.

[0058] Second Embodiment A turbine 1 according to a second embodiment of the present disclosure will be described. The turbine 1 according to the second embodiment differs from the turbine 1 according to the first embodiment in the shape of one side surface 24a of the first shroud 24. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0059] (composition) Fig. 6 is an enlarged view of the periphery of one side surface 24a of the first shroud 24 according to the second embodiment. In the second embodiment, as illustrated in Fig. 6, the one side surface 24a of the first shroud 24 includes an inward stepped surface 80 that faces inward in the radial direction D2. The other side surface 44b of the second shroud 44 includes an outward stepped surface 82 that faces outward in the radial direction D2.

[0060] In the second embodiment, the one side surface 24a of the first shroud 24 includes an inward stepped surface 80, a first inner side surface 81, and a first outer side surface 83. The first inner side surface 81 extends outward in the radial direction D2 from an inner end e2 of the one side surface 24a of the first shroud 24. The first outer side surface 83 extends inward in the radial direction D2 from an outer end e1 of the one side surface 24a of the first shroud 24. The inward stepped surface 80 extends along the circumferential direction D3 and connects the first inner side surface 81 and the first outer side surface 83.

[0061] The other-side side surface 44b of the second shroud 44 includes an outward stepped surface 82, a second inner surface 85, and a second outer surface 87. The second inner surface 85 extends outward in the radial direction D2 from an inner end e8 of the other-side side surface 44b of the second shroud 44. The second outer surface 87 extends inward in the radial direction D2 from an outer end e7 of the other-side side surface 44b of the second shroud 44. The outward stepped surface 82 extends along the circumferential direction D3 and connects the second inner surface 85 and the second outer surface 87.

[0062] Each of the inward step surface 80 and the outward step surface 82 has a planar shape consisting of a flat surface. The inward step surface 80 and the outward step surface 82 extend parallel to each other along the axial direction D1. The inward step surface 80 includes a portion 24a1 of the one-side side surface 24a that is included in the first overlap region R1. The outward step surface 82 includes a portion 44b1 of the other-side side surface 44b that is included in the first overlap region R1.

[0063] (Actions and Effects) The following describes the operation and effect of the turbine 1 according to the second embodiment. According to the second embodiment, compared to the first embodiment, it is easier to control the area where the other side surface 44b of the second shroud 44 contacts or presses against the one side surface 24a of the first shroud 24 during operation of the turbine 1. Therefore, vibrations of the turbine 1 can be suppressed as intended.

[0064] In the second embodiment, the case where the one side surface 24a of the first shroud 24 is stepped has been described, but the one side surface 44a of the second shroud 44 may also be stepped.

[0065] Third Embodiment A turbine 1 according to a third embodiment of the present disclosure will be described. The turbine 1 according to the third embodiment is obtained by further limiting the configuration of the turbine 1 according to the first embodiment. In the third embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0066] (composition) FIG. 7 is a diagram schematically showing the internal configuration of a first rotor blade 20 and an internal configuration of a second rotor blade 40 according to the third embodiment.

[0067] In the third embodiment, as illustrated in Fig. 7 , a first cooling channel 90 is formed inside the first rotor blade 20, through which a first refrigerant F1 for cooling the first rotor blade 20 flows. The inlet and outlet of the first cooling channel 90 are formed in the blade root 23 of the first rotor blade 20, on the opposite side of the tip 22 of the first rotor blade 20 in the radial direction D2. A second cooling channel 92 is formed inside the second rotor blade 40, through which a second refrigerant F2 for cooling the second rotor blade 40 flows. The inlet and outlet of the second cooling channel 92 are formed in the blade root 43 of the second rotor blade 40, on the opposite side of the tip 22 of the first rotor blade 20 in the radial direction D2. The second refrigerant F2 is the same refrigerant as the first refrigerant F1.

[0068] The first cooling surface 91 defining the first cooling passage 90 has a larger area than the second cooling surface 93 defining the second cooling passage 92. In a third embodiment, the first cooling passage 90 is longer than the second cooling passage 92. In some embodiments, the first cooling passage 90 has a larger flow cross-section than the second cooling passage 92.

[0069] (Actions and Effects) The operation and effect of the turbine 1 according to the third embodiment will be described. According to the third embodiment, the first cooling surface 91 has a larger area than the second cooling surface 93, and therefore, thermal expansion acting on the second rotor blade 40 is greater than that acting on the first rotor blade 20. That is, the second rotor blade 40 extends longer in the radial direction D2 due to thermal expansion than the first rotor blade 20. Therefore, during operation of the turbine 1, not only the difference in magnitude between the centrifugal force acting on the second rotor blade 40 and the centrifugal force acting on the first rotor blade 20 but also the difference in magnitude between the thermal expansion acting on the second rotor blade 40 and the first rotor blade 20 is utilized to cause a portion 44b1 of the other side surface 44b of the second shroud 44 to slide against a portion 24a1 of the one side surface 24a of the first shroud 24. This achieves an even greater damping effect due to friction.

[0070] The configurations of the first rotor blade 20 and the second rotor blade 40 according to the third embodiment illustrated in FIG. 7 may be applied to the turbine 1 according to the second embodiment.

[0071] <Fourth embodiment> (composition) A turbine 1 according to a fourth embodiment of the present disclosure will now be described. Fig. 8 is a diagram schematically showing the configuration of the turbine 1 according to the fourth embodiment. Fig. 8 shows two turbine rotor blades 2 included in the turbine rotor blade row 10 of Fig. 1.

[0072] In the fourth embodiment, as illustrated in Fig. 8, the turbine 1 includes a rotor disk 14 fixed to the turbine rotor 3. The rotor disk 14 is fixed to the turbine rotor 3, for example, by being fitted into a hole formed in the outer circumferential surface of the turbine rotor 3. In some embodiments, the rotor disk 14 is fixed to the turbine rotor 3 by a fastener such as a bolt.

[0073] The plurality of turbine rotor blades 2 include a fourth turbine rotor blade 2D(2) and a fifth turbine rotor blade 2E(2).

[0074] The fourth turbine rotor blade 2D includes a fourth rotor blade 200 and a fourth shroud 204 provided at a tip 202 of the fourth rotor blade 200. The fourth rotor blade 200 extends outward in the radial direction D2 from the rotor disk 14. The fourth shroud 204 has a plate shape and extends from the tip 202 of the fourth rotor blade 200 to both sides in the circumferential direction D3.

[0075] The fifth turbine rotor blade 2E includes a fifth rotor blade 210 and a fifth shroud 214 provided at a tip 212 of the fifth rotor blade 210. The fifth rotor blade 210 is disposed adjacent to the fourth rotor blade 200 on one side in the circumferential direction D3. The fifth rotor blade 210 extends outward in the radial direction D2 from the rotor disk 14. A space through which combustion gas G3 flows is formed between the fourth rotor blade 200 and the fifth rotor blade 210 in the circumferential direction D3. The fifth shroud 214 has a plate shape and extends from the tip 212 of the fifth rotor blade 210 to both sides in the circumferential direction D3.

[0076] In the fourth embodiment, the fourth rotor blade 200 and the fifth rotor blade 210 are configured to have the same shape as each other. Furthermore, the fourth rotor blade 200 and the fifth rotor blade 210 are configured from the same material.

[0077] In the fourth embodiment, the turbine 1 employs a configuration in which the fourth turbine rotor blades 2D, the fifth turbine rotor blades 2E, and the rotor disk 14 are separate bodies. The fourth turbine rotor blades 2D and the fifth turbine rotor blades 2E are attached to the rotor disk 14 by a mechanical connection method such as fitting.

[0078] A third overlap region R3 is a region where the one side surface 204a of the fourth shroud 204 and the other side surface 214b of the fifth shroud 214 overlap with each other in the circumferential direction D3. As illustrated in Fig. 8, in the third overlap region R3, the one side surface 204a of the fourth shroud 204 is located outward in the radial direction D2 from the other side surface 214b of the fifth shroud 214.

[0079] FIG. 9 is a diagram schematically showing the internal configuration of a fourth rotor blade 200 and a fifth rotor blade 210 according to the fourth embodiment.

[0080] In the fourth embodiment, as illustrated in Fig. 9, a fourth cooling channel 206 is formed inside the fourth bucket 200, through which a fourth refrigerant F4 for cooling the fourth bucket 200 flows. The inlet and outlet of the fourth cooling channel 206 are formed in the blade root 203 of the fourth bucket 200, on the opposite side of the tip 202 of the fourth bucket 200 in the radial direction D2. The fifth bucket 210 is formed inside a fifth cooling channel 216, through which a fifth refrigerant F5 for cooling the fifth bucket 210 flows. The inlet and outlet of the fifth cooling channel 216 are formed in the blade root 213 of the fifth bucket 210, on the opposite side of the tip 212 of the fifth bucket 210 in the radial direction D2. The fifth refrigerant F5 is the same refrigerant as the fourth refrigerant F4.

[0081] The fourth cooling surface 207 defining the fourth cooling channel 206 has a larger area than the fifth cooling surface 217 defining the fifth cooling channel 216. In the fourth embodiment, the fourth cooling channel 206 is longer than the fifth cooling channel 216. In some embodiments, the fourth cooling channel 206 has a larger channel cross-section than the fifth cooling channel 216.

[0082] (Actions and Effects) The operation and effect of the turbine 1 according to the fourth embodiment will be described. According to the fourth embodiment, the fourth cooling surface 207 has a larger area than the fifth cooling surface 217. Therefore, during operation of the turbine 1, the elongation of the fifth bucket 210 due to thermal expansion acting on the fifth bucket 210 is larger than the elongation of the fourth bucket 200 due to thermal expansion acting on the fourth bucket 200. In the third overlap region R3, the one side surface 204a of the fourth shroud 204 is located outward in the radial direction D2 from the other side surface 214b of the fifth shroud 214. Therefore, the other side surface 214b of the fifth shroud 214 comes into contact with or presses the one side surface 204a of the fourth shroud 204. Therefore, when one or both of the fourth turbine rotor blades 2D and the fifth turbine rotor blades 2E vibrate, the other side surface 214b of the fifth shroud 214 slides against the one side surface 204a of the fourth shroud 204, thereby achieving a high damping effect due to friction.

[0083] The contents described in each of the above embodiments can be understood, for example, as follows.

[0084] [1] The turbine (1) according to the present disclosure includes: A rotor (3), a plurality of turbine blades (2) arranged along a circumferential direction (D3) of the rotor, the plurality of turbine blades include a first turbine blade (2A) including a first rotor blade (20) and a first shroud (24) provided at a tip portion (22) of the first rotor blade, and a second turbine blade (2B) including a second rotor blade (40) arranged adjacent to the first rotor blade on one side in the circumferential direction of the rotor and a second shroud (44) provided at a tip portion (42) of the second rotor blade, in an overlapping region (R1) where at least a portion (24a1) of one side surface (24a) of the first shroud on one side in the circumferential direction and at least a portion (44b1) of the other side surface (44b) of the second shroud on the other side in the circumferential direction overlap in the circumferential direction, the one side surface is located outward in the radial direction (D2) from the other side surface, The second shroud is heavier than the first shroud.

[0085] According to the configuration described in [1] above, since the second shroud is heavier than the first shroud, the centrifugal force acting on the second rotor blades during turbine operation is greater than the centrifugal force acting on the first rotor blades. Therefore, the second rotor blades extend radially longer than the first rotor blades. Furthermore, in the overlapping region, the one side surface of the first shroud is located radially outward of the other side surface of the second shroud, so that at least a portion of the other side surface of the second shroud contacts or presses against at least a portion of the one side surface of the first shroud. Therefore, when one or both of the first turbine blades or the second turbine blades vibrate, at least a portion of the other side surface of the second shroud slides against at least a portion of the one side surface of the first shroud, thereby achieving a high damping effect due to friction.

[0086] [2] In some embodiments, in the configuration described in [1] above, The length of the first shroud in the circumferential direction is shorter than the length of the second shroud in the circumferential direction.

[0087] According to the configuration described in [2] above, the first shroud and the second shroud have different shapes, and therefore the static deformation characteristics of the first turbine blade and the second turbine blade during turbine operation are different from each other. As a result, the natural frequencies of the first turbine blade and the second turbine blade are non-uniform, and a so-called mistuned structure can be adopted for the turbine, thereby suppressing turbine vibration.

[0088] [3] In some embodiments, in the configuration described in [1] or [2] above, Each of the one side surface and the other side surface is formed by a cut surface (72) obtained by cutting an integrated shroud (70) in which the first shroud and the second shroud are integrally formed.

[0089] According to the configuration described in [3] above, one side surface and the other side surface can be formed simultaneously by simply cutting the integrated shroud, which reduces the amount of work required to process the turbine compared to the case where a separate part (pin) needs to be created as described in Patent Document 1.

[0090] [4] In some embodiments, in the configuration described in any one of [1] to [3] above, Each of the one side surface and the other side surface has a planar shape consisting of a flat surface as a whole.

[0091] According to the configuration described in [4] above, the overlapping region can be formed with a simple configuration, and the one side surface can be positioned radially outward relative to the other side surface.

[0092] [5] In some embodiments, in the configuration described in any one of [1] to [3] above, The one side surface includes an inward stepped surface (80) facing inward in the radial direction, The other side surface includes an outward stepped surface (82) facing outward in the radial direction.

[0093] According to the configuration described in [5] above, it is easier to control the area where the other side surface contacts or presses against the one side surface during operation of the turbine, compared to the configuration described in [4] above.

[0094] [6] In some embodiments, in the configuration described in any one of [1] to [5] above, the plurality of turbine blades further include a third turbine blade (2C) including a third rotor blade (60) arranged adjacent to the second rotor blade on one side in the circumferential direction of the rotor and a third shroud (64) provided at a tip portion (62) of the third rotor blade, in a second overlap region (R2) where at least a portion (44a1) of one side surface (44a) on one side in the circumferential direction of the second shroud and at least a portion (64b1) of another side surface (64b) on the other side in the circumferential direction of the third shroud overlap in the circumferential direction, the another side surface on the other side in the circumferential direction of the third shroud is located radially outward of the one side surface on the one side in the circumferential direction of the second shroud, The second shroud is heavier than the third shroud.

[0095] According to the configuration described in [6] above, since the second shroud is heavier than the third shroud, the centrifugal force acting on the second rotor blades during turbine operation is greater than the centrifugal force acting on the third rotor blades. Therefore, the second rotor blades extend radially longer than the third rotor blades. Furthermore, in the second overlap region, the other side surface of the third shroud is located radially outward of the one side surface of the second shroud, so that at least a portion of the one side surface of the second shroud contacts or presses against at least a portion of the other side surface of the third shroud. Therefore, when one or both of the second turbine blades and the third turbine blades vibrate, at least a portion of the one side surface of the second shroud slides against at least a portion of the other side surface of the third shroud, thereby achieving a high damping effect due to friction.

[0096] [7] In some embodiments, in the configuration described in any one of [1] to [6] above, a first cooling flow path (90) through which a coolant (F1) for cooling the first rotor blade flows is formed inside the first rotor blade; a second cooling flow path (92) through which a coolant (F2) for cooling the second rotor blade flows is formed inside the second rotor blade, A first cooling surface (91) defining the first cooling flow path has a larger area than a second cooling surface (93) defining the second cooling flow path.

[0097] According to the configuration described in [7] above, by utilizing not only the difference in magnitude of the centrifugal force acting on the second rotor blade and the centrifugal force acting on the first rotor blade but also the difference in magnitude of the thermal expansion acting on the second rotor blade and the thermal expansion acting on the first rotor blade, at least a part of the other side surface of the second shroud slides against at least a part of the one side surface of the first shroud during turbine operation, thereby achieving an even higher damping effect due to friction.

[0098] [8] The turbine according to the present disclosure comprises: A rotor (3), a plurality of turbine blades (2) arranged along a circumferential direction (D3) of the rotor, the plurality of turbine blades include a first turbine blade (2D) including a first rotor blade (200) and a first shroud (204) provided at a tip portion (202) of the first rotor blade, and a second turbine blade (2E) including a second rotor blade (210) arranged adjacent to the first rotor blade on one side in the circumferential direction of the rotor and a second shroud (214) provided at a tip portion (212) of the second rotor blade, in an overlapping region (R3) where at least a part of one-side side surface (204a) on one side in the circumferential direction of the first shroud and at least a part of another-side side surface (214b) on the other side in the circumferential direction of the second shroud overlap in the circumferential direction, the one-side side surface is located outward in the radial direction (D2) from the other-side side surface, a first cooling flow path (206) through which a coolant (F4) for cooling the first rotor blade flows is formed inside the first rotor blade; a second cooling flow path (216) through which a coolant (F5) for cooling the second rotor blade flows is formed inside the second rotor blade; The first cooling surface (207) defining the first cooling channel has a larger area than the second cooling surface (217) defining the second cooling channel.

[0099] According to the configuration described in [8] above, since the first cooling surface has a larger area than the second cooling surface, during turbine operation, the elongation of the second rotor blade due to thermal expansion acting on the second rotor blade is greater than the elongation of the first rotor blade due to thermal expansion acting on the first rotor blade. Furthermore, in the overlap region, the one side surface of the first shroud is located radially outward of the other side surface of the second shroud, so that at least a portion of the other side surface of the second shroud contacts or presses against at least a portion of the one side surface of the first shroud. Therefore, when one or both of the first turbine blade and the second turbine blade vibrate, at least a portion of the other side surface of the second shroud slides against at least a portion of the one side surface of the first shroud, thereby achieving a high damping effect due to friction. [Explanation of symbols]

[0100] 1 turbine 2. Turbine blades 2A No. 1 turbine blade 2B No. 2 turbine blade 2C No. 3 turbine blade 2D No. 4 turbine blade 2E No. 5 turbine blade 3 Turbine rotor 14 rotor disc 20 1st rotor blade 22 Tip of first rotor blade 24 First Shroud 24a One side of the first shroud 24a1 Part of one side of the first shroud 40 2nd moving blade 42 Tip of second rotor blade 44 Second Shroud 44a One side of the second shroud 44a1 Part of one side of the second shroud 44b The other side of the second shroud 44b1 Part of the other side of the second shroud 60 Third moving blade 62 Tip of third rotor blade 64 Third Shroud 64b The other side of the third shroud 64b1 Part of the other side of the third shroud 70 One-piece shroud 72 1st cutting plane 74 Second cutting plane 80 Inward step surface 82 Outward step surface 90 First cooling channel 91 1st cooling surface 92 Second cooling channel 93 Second cooling surface 200 4th moving blade 202 Tip of the fourth rotor blade 204 Fourth Shroud 204a One side of the fourth shroud 206 4th cooling channel 207 4th cooling surface 210 5th moving blade 212 Tip of No. 5 rotor blade 214 5th Shroud 214b The other side of the fifth shroud 216 5th cooling channel 217 5th cooling surface C1 First cutting line C2 Second cutting line D1 Axial direction D2 radial direction D3 Circumferential direction F1 First refrigerant F2 Second refrigerant F4 4th refrigerant F5 5th refrigerant O axis R1 1st overlap area R2 2nd overlap area R3 3rd overlap area

Claims

1. A rotor, a plurality of turbine blades arranged along the circumferential direction of the rotor, the plurality of turbine blades include a first turbine blade including a first rotor blade and a first shroud provided at a tip of the first rotor blade, and a second turbine blade including a second rotor blade arranged adjacent to the first rotor blade on one side in the circumferential direction of the rotor and a second shroud provided at a tip of the second rotor blade, in an overlap region in which at least a portion of a one-side surface of the first shroud on the one side in the circumferential direction and at least a portion of a other-side surface of the second shroud on the other side in the circumferential direction overlap in the circumferential direction, the one-side surface is located radially outward of the other-side surface, the second shroud is heavier than the first shroud; a first cooling flow path through which a coolant for cooling the first rotor blade flows is formed inside the first rotor blade; a second cooling flow path through which a coolant for cooling the second rotor blade flows is formed inside the second rotor blade, a first cooling surface defining the first cooling passage has an area larger than a second cooling surface defining the second cooling passage, whereby thermal expansion acting on the second blade is larger than thermal expansion acting on the first blade; Turbine.

2. a length of the first shroud in the circumferential direction is shorter than a length of the second shroud in the circumferential direction; The turbine of claim 1 .

3. Each of the one side surface and the other side surface has a planar shape consisting of an entirely flat surface. A turbine according to claim 1 or 2.

4. the one-side side surface includes an inward step surface facing inward in the radial direction, The other side surface includes an outward stepped surface facing outward in the radial direction. A turbine according to claim 1 or 2.

5. the plurality of turbine blades further include a third turbine blade including a third rotor blade arranged adjacent to the second rotor blade on one side in the circumferential direction of the rotor and a third shroud provided at a tip of the third rotor blade, in a second overlap region in which at least a portion of a one-side side surface on the one side in the circumferential direction of the second shroud and at least a portion of a other-side side surface on the other side in the circumferential direction of the third shroud overlap in the circumferential direction, the other-side side surface on the other side in the circumferential direction of the third shroud is located radially outward of the one-side side surface on the one side in the circumferential direction of the second shroud, The second shroud is heavier than the third shroud. A turbine according to any one of claims 1 to 4.

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