JPH09310603A - Gas turbine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas turbine whose performance of plant efficiency and reliability are not deteriorated by leakage of steam, even in the case that flow passages of coolant penetrate connection surfaces betwen a moving blade and a rotor shaft body. SOLUTION: A gas turbine rotor shaft body 8 is provided. A moving blade 1 is parallelly arranged around the rotor shaft in a circumferential direction and includes a coolant flow passage thereinside. Coolant supply/discharge passages 11, 12 penetrate connection surfaces between the moving blade 1 and the rotor shaft body 8 for supplying and discharging the coolant with respect to the coolant flow passage of the moving blade 1. In such a gas turbine, recessions 20 are formed around the passages penetrating the connection surface, at the connection surface between the moving blade 1 and the rotor shaft body 8. A member 25 which performs elastic deformation is arranged in each recession 20. Step or inclination is formed on the connection surface in an axial direction of the rotor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a gas turbine, and more particularly to a gas turbine in which a cooling medium supply / discharge passage for cooling a moving blade is provided so as to penetrate a joint surface between the moving blade and a rotor. It is about.

[0002]

2. Description of the Related Art In a gas turbine of this type that has been generally adopted in the past, high-pressure compressed air is generated by a compressor directly connected to a turbine shaft, and fuel is added to the compressed air to burn the compressed air. Is used to drive a turbine by obtaining a high-temperature and high-pressure working fluid. The rotational energy of this turbine is generally converted to electrical energy by a generator coupled to the turbine.

Recently, great expectations have been placed on improving the performance and efficiency of a combined cycle in which a gas turbine and a steam turbine are combined. In order to improve the performance and efficiency of the combined cycle, it is necessary to further increase the temperature and pressure of the working fluid of the gas turbine.
Therefore, even if the temperature of the working fluid of the gas turbine is made higher than ever before, the high temperature part of the gas turbine is actively cooled by steam, and the steam whose temperature has risen is recovered and used to drive the steam turbine. There is an urgent need to develop a highly efficient and highly reliable combined plant that recovers thermal energy.

When cooling the gas turbine blade using the steam as the cooling medium on the premise of recovering the cooling medium, the major problem is the leakage of the steam as the cooling medium. Japanese Patent Laid-Open No. 6-257403 discloses, for example, a gas turbine related to the gas turbine.

That is, in the air-cooled gas turbine that has been adopted in many gas turbines in the past, FIG.
As also shown in FIG. 1, the rotor blades 1 are arranged side by side in the circumferential direction around the rotor shaft body 8, and the coupling thereof is provided on the base side (rotor shaft body side) of the rotor blades 1. The blade dovetail protrusions 2 and the dovetail recesses 9 provided on the outer circumference of the rotor shaft engage with each other and are fixedly coupled.

As for the cooling of the moving blade, the cooling air 33b and 33c for the moving blade is formed between the moving blade dovetail portion 2 and the rotor shaft dovetail 9 as shown in the cross section of FIG. It is formed so as to be supplied from the cavity 80.

[0007]

In this case, since the moving blade 1 and the rotor shaft body 8 are rotating bodies, a centrifugal force naturally acts, and the moving blade is arranged outside the rotor shaft body in the radius of rotation. Because of this, a larger centrifugal force acts, and a slight gap 6 is formed at the joint between the bottom surface of the rotor blade dovetail portion 2 and the rotor shaft body 8.
5 results. Here, supply cooling air 33b and 33c
Is supplied a little higher than the ambient pressure, so that the cooling air leaks to the outside through this gap 65. However, in the conventional air-cooled gas turbine, the cooling air after cooling the moving blades is finally discharged into the mainstream gas, so that the pressure difference between the cooling air supplied in the cavity and the outside may be relatively small, and the gap 65 The leakage of cooling air was relatively small, and it did not pose a problem so as to have a particularly large influence on the performance of the gas turbine.

However, in the case of performing steam cooling on the premise of recovery, the steam is higher than that in the case of air cooling in consideration of obtaining the recovery pressure to some extent and considering the pressure loss in the moving blade. Since the pressure is supplied, a large amount of steam leaks from a small gap due to the large pressure difference. In addition, leaking steam may cause a significant loss in exhaust heat recovery in a system that requires recovery of the cooling medium.

According to a cycle survey, there is a report that a loss of 1% of steam amount with respect to a gas turbine compressor inlet air flow rate due to leakage leads to a decrease in combined efficiency by 0.7 point. Further, if steam leaks, the surrounding members may be corroded by the steam, and there is a risk that the reliability of the gas turbine as a whole is significantly impaired.

The present invention has been made in view of the above circumstances, and an object thereof is to cool a cooling medium even if it is provided so as to penetrate a joint surface between a rotor blade and a rotor shaft. It is an object of the present invention to provide a gas turbine of this type, which has no medium leakage, and does not cause performance deterioration of plant efficiency or reliability of the gas turbine itself due to steam leakage.

[0011]

That is, the present invention comprises a gas turbine rotor shaft, and rotor blades which are arranged side by side in the circumferential direction around the rotor shaft and have a cooling medium flow passage therein. In a gas turbine in which a cooling medium supply / discharge passage for supplying / discharging a cooling medium to / from a cooling medium flow passage of the moving blade is provided so as to penetrate a joint surface between the moving blade and the rotor shaft body, the moving blade and the rotor are provided. A concave groove is provided on the joint surface with the shaft body and around the supply / discharge passage penetrating the joint surface, and an elastically deformable member is arranged in the concave groove, and a step in the rotor axial direction is formed on the joint surface. It is provided so as to achieve the intended purpose.

The cooling medium supply path and the cooling medium discharge path at the joint surface portion between the rotor blade and the rotor shaft are provided in parallel in the rotor axial direction, and the joint surface between the rotor blade and the rotor shaft is provided at the joint surface. It is formed so as to have a step in the direction, and concave grooves are provided around the cooling medium supply path and the cooling medium discharge path of the joint surface, and elastically deformable members are arranged in the respective concave grooves. It is a thing.

Further, in this case, the supply passage and the discharge passage of the cooling medium in the joint surface portion between the rotor blade and the rotor blade are provided on the surfaces having different steps. Further, the concave groove on the joint surface is provided on the joint surface on the rotor shaft side. Further, the elastically deformable member is formed of a metal O-ring or a rod-shaped metal pin.

The gas turbine rotor shaft is provided with a rotor blade arranged circumferentially in parallel around the rotor shaft body and having a cooling medium flow passage therein. The cooling medium flow passage of the rotor blade is provided. In a gas turbine in which a cooling medium supply passage for supplying the cooling medium to the cooling medium and a cooling medium discharge passage for discharging the cooling medium from the cooling medium flow passage are provided so as to penetrate the joint surface between the rotor blade and the rotor shaft, A cooling medium supply path and a cooling medium discharge path are provided side by side in the rotor axial direction at the joint surface portion between the rotor blade and the rotor shaft, and the joint surface between the rotor blade and the rotor shaft body is arranged with respect to the insertion direction of the rotor blade. , Having a slope, and provided with concave grooves around the cooling medium supply passage and the cooling medium discharge passage on the joint surface, and elastically deforming members are arranged in the respective concave grooves. Is.

That is, in the gas turbine thus formed, the elastically deformable member arranged at the joint of the rotor shaft and the cooling medium flow passage between the rotor blade and the rotor blade is connected to the rotor shaft body of the rotor blade. The damage received during insertion is mitigated.Therefore, in the steam-cooled recovery type gas turbine, it is possible to eliminate the gap at the joint of the cooling medium supply flow path that occurs during gas turbine operation, and to sufficiently prevent the leakage of steam that is the cooling medium. Even if the cooling medium flow passage is provided so as to penetrate through the joint surface between the rotor blade and the rotor shaft, there is no leakage of the cooling medium, and there is a decrease in plant efficiency performance or gas due to steam leakage. It is possible to sufficiently prevent the reliability of the turbine itself from being lowered.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the illustrated embodiments. FIG. 1 shows a cross section around the rotor blade of the gas turbine, and FIG. 2 shows a rotor shaft joint surface to be joined to the rotor blade.

In these figures, 1 is a rotor blade, 2 is a rotor blade dovetail portion, 8 is a rotor shaft, 10 is a cooling steam supply passage (cooling medium supply passage) for the rotor blade 1, and 12 is a rotor blade 1. Of the cooling steam recovery passage (cooling medium discharge passage), 14 is a cooling steam supply passage to the rotor blade 1 provided inside the rotor shaft body 8, and 16 is a movement passage provided inside the rotor shaft body 8. It is a cooling vapor recovery flow path from the blade 1. Further, 11 is a cooling steam intake port of the moving blade 1, 13 is a cooling steam discharge port of the moving blade 1, 15 is a cooling steam supply port to the moving blade 1 provided on the rotor shaft body 8, and 17 is also the rotor shaft. It is a cooling steam recovery port from the rotor blade 1 provided in the body 8.

In this structure, the cooling steam suction port 11 of the rotor blade dovetail portion 2 and the cooling steam supply port 1 of the rotor shaft 8 are provided.
5 and a joint surface between the cooling steam discharge port 13 of the rotor blade dovetail portion 2 and the cooling steam recovery port 17 of the rotor shaft body 8 are both formed parallel to the rotor blade insertion direction 51. Here, a seal groove (concave groove) 20 is formed on the rotor shaft 8 side at a joint between the cooling steam inlet 11 of the rotor blade dovetail portion 2 and the cooling steam supply port 15 of the rotor shaft 8. . Similarly, a seal groove 21 is formed at the joint between the cooling steam discharge port 13 of the rotor blade dovetail portion 2 and the cooling steam recovery port 17 of the rotor shaft body 8. These seal grooves 20 and 2
1 includes metal O-rings 24 and 25 which are elastically deformable bodies.
Is inserted in a compressed and elastically deformed state.

Next, the operating principle of the thus-formed gas turbine rotor blade and rotor shaft body will be described. The cooling steam 30 supplied to the rotor blade 1 is the cooling steam supply passages 14 and 10.
After cooling the moving blade 1, the recovered cooling steam 32 is recovered through the cooling steam recovery passages 12 and 16. FIG. 3 shows a state of the gas turbine rotor blade and the rotor shaft body during operation of the gas turbine having the structure of the present invention. Since the rotor blade 1 and the rotor shaft body 8 are rotating bodies, centrifugal force naturally works during operation.

A larger centrifugal force 60 acts on the moving blade 1 whose radius of rotation is outside the rotor shaft 8. As a result, gaps 65a, 65b, 65c are formed at the joint between the bottom surface of the rotor blade dovetail portion 2 and the rotor shaft body 8. However, in this structure of the present invention, even if a gap is created in the joint between the bottom surface of the rotor blade dovetail portion 2 and the rotor shaft body 8, the metal O-rings 24 and 25, which are elastic deformable bodies, are restored and deformed, and the rotor blade The metal O-ring 24 is kept in close contact between the periphery of the cooling steam intake port 11 and the periphery of the cooling shaft supply port 15 of the rotor shaft body, and the periphery of the cooling steam discharge port 13 and the cooling steam recovery port of the rotor shaft body. 1
Adhesion with the metal O-ring 25 is maintained between the surroundings.

Therefore, the supply cooling steam 30 has the gap 65.
a to the outside, and also to the outside through the recovery cooling steam 32 gap 65c. Further, the supply cooling steam 30 does not contribute to the cooling of the moving blade 1 through the clearance 65b and the recovery cooling steam 32 side. Can be prevented from leaking to.

By forming in this way, the leakage of steam, which is the cooling medium, to the outside can be significantly reduced, and the efficiency and performance of the entire power plant can be prevented from deteriorating.
Further, by preventing steam from leaking to the surroundings, problems such as corrosion of surrounding members are eliminated, and reliability of the gas turbine can be improved.

In the above description, both the seal grooves 20 and 21 are provided on the rotor shaft body 8 side, but this is also possible if one or both of the seal grooves 20 and 21 are provided on the rotor blade dovetail portion 2 side. Similar effects can be obtained, and the structure is not particularly limited. Also, the seal grooves 20 and 21
The metal O-rings 24 and 25 inserted in the
The effect is not particularly limited as long as it is an elastic O-ring that can withstand up to about 500 ° C., and is not particularly limited.

Further, in FIGS. 1 and 2, the seal groove 20 is used.
And 21 are not provided on the same plane but on different planes parallel to each other. This is a structure that is effective when the rotor blade 1 is assembled and arranged on the rotor shaft body 8. In FIG.
At the time of assembly, the rotor blade 1 is inserted into the rotor shaft body 8 which is stationary along the direction of the arrow 51 which is the same as the rotation axis of the gas turbine. When the rotor blade 1 is inserted, the rotor blade 1 contacts the bottom surface 3 of the rotor blade dovetail portion 2 with the metal O-ring 24 and slides on the metal O-ring 24 to compress and deform the metal O-ring 24 from above. , The bottom surface 4 of the blade dovetail portion 2
Is brought into contact with the metal O-ring 25, and the metal O-ring 25 is slid on the metal O-ring 25 so that the metal O-ring 25 is compressed and deformed from above and is inserted to a predetermined position.

Now, let us consider a case where the seal grooves 20 and 21 are on the same plane. The rotor blade 1 is inserted by first compressing and deforming the metal O-ring 24 on the bottom surface 4 of the rotor blade dovetail portion 2 by the method described above, and then similarly compressing and deforming the metal O-ring 25. After the metal O-ring is compressed and deformed, a force acts on the seal surface due to a restoring force. Therefore, it is not desirable to rub the seal surface on the seal surface because scratches and the like easily occur.

In this case, however, the metal O-ring 24 will continue to be rubbed on its sealing surface until the bottom surface 4 of the blade dovetail portion reaches a predetermined position.
It may damage the sealing surface of 4. On the other hand, the seal grooves 20 and 2
In the structure in which 1 is provided on different planes, since the bottom surface of the blade dovetail portion 2 is divided into two different planes, the distance that the metal O-ring 24 near the insertion side is rubbed on the bottom surface of the blade dovetail portion is short. In addition, there is an advantage that it can reduce the damage to the metal O-ring.

Next, a modification of the present invention will be shown. FIG. 4 is a partial cross-sectional view of the rotor blade dovetail portion and the rotor shaft body, and FIG. 5 is a top view of the rotor shaft body joint surface. In these drawings, the basic structure and operating principle are the same as those in FIG. 1, but in FIG. 4, a minute gradient 70 is provided at the joint between the rotor blade dovetail portion 2 and the rotor shaft body 8, and the seal groove 20b and Two
1b is also formed so as to match the joint surface having the slope 70.

A metal O-ring 24 is provided in the seal groove 20b.
However, the metal O-ring 25 is inserted in the seal groove 21b. Here, since the gradient 70 is very small, the metal O-rings 24 and 25 are restored and deformed during the gas turbine operation as in the structure shown in FIG. 1, and the surroundings of the cooling steam intake port 11 of the rotor blade and the rotor shaft body. The leakage of cooling steam is prevented by maintaining close contact with the periphery of the cooling steam supply port 15 and between the periphery of the cooling steam discharge port 13 of the moving blade and the periphery of the cooling steam recovery port 17 of the rotor shaft.

FIG. 6 is a view showing a state in which the rotor blade 8 is being inserted while the rotor blade 1 is being incorporated. The rotor blade 1 is inserted into the rotor shaft body 8 along the direction of the arrow 51, which is the same as the rotation axis of the gas turbine, as in the case of FIG. At this time, the slope is 7 on the joint surface.
Since 0 is attached and the insertion direction is 51, the distance 67 between the bottom surface 7 of the rotor blade dovetail portion 2 and the joint surface of the rotor shaft body 8 is initially secured to some extent. Linearly decreases as the wing 1 is inserted,
When it is completely inserted, it becomes almost 0.

That is, in the structure shown in FIG. 1, the metal O-rings 24 and 2 are formed on the bottom surfaces 3 and 4 of the rotor blade dovetail.
5 is compressed and elastically deformed while sliding on the top surface of the rotor blade 5, the metal O-ring can be pressed and compressed from above by the bottom surface 7 of the rotor blade dovetail portion in this structure. Is easier than the above-mentioned example, the possibility of damaging the sealing surface of the metal O-ring is further reduced, and the reliability of the leakage prevention effect of steam as a cooling medium is improved. Also in this modification, the same effect can be obtained even if one or both of the seal grooves 20b and 21b are provided on the rotor blade dovetail side, and there is no particular limitation.

Although the elastic deformable body has been described above with respect to the annular metal O-ring, the elastic deformable body is not particularly limited as long as it has a structure suitable for sealing. In FIG. 7, the blade dovetail portion 2 is shown. 2 shows a case where the elastically deformable body inserted in the joint portion between the rotor shaft body 8 and the rotor shaft body is a metal pin having a rod shape and a circular cross section. FIG. 8 is a top view of the rotor shaft joint surface. In these drawings, the sealing groove 2 is formed by sandwiching the cooling steam supply flow paths 10 and 14 and the cooling steam recovery flow paths 12 and 16 from both sides.
6, 27 and 28 are formed on the rotor shaft side, and the metal pin 41 is inserted into the seal groove 26, the metal pin 42 is inserted into the seal groove 27, and the metal pin 43 is inserted into the seal groove 28 while being elastically deformed. Has been done.

Even in the structure constructed as described above, even if a gap is generated in the joint surface between the rotor blade dovetail portion 2 and the rotor shaft body 8 during the operation of the gas turbine, as shown in FIGS. 1, 3 and 4. Similar to the case of the metal O-rings 24 and 25 of the structure, the metal pins 41, 42, 43 are restored and deformed to prevent the leakage of the cooling steam. Here, the effect is the same even if the cross section of the metal pin is not limited to a circular shape but an elliptical shape, and is not particularly limited as long as it is a shape that effectively restores and deforms and maintains the sealing surface.

In this structure as well, the seal grooves 26, 2
It is possible to provide a part or all of 7, 28 on the blade dovetail portion 2 side, and there is no particular limitation. Further, if the seal grooves 26, 27, and 28 are arranged on different planes that are parallel to each other, the moving blade 1 can be provided in the same manner as the effect that the seal grooves 20 and 21 are arranged on different planes in the structure shown in FIG. When the rotor blade 8 is inserted into the rotor shaft body 8, the distance by which the bottom surface of the rotor blade dovetail portion 2 slides on the sealing surface of the metal pins 41 and 42 becomes shorter, and the sealing surface can be prevented from being damaged. Further, if a slight gradient is provided at the joint between the rotor blade dovetail portion 2 and the rotor shaft body 8,
Similar to the structure shown in FIG. 4, when inserting the rotor blade 1 into the rotor shaft body 8, the metal pins 41, 4 can be easily and effectively inserted.
2, 43 can be compressed and deformed.

Although the embodiments of the present invention have been described above, the structure of the present invention can be applied to various cooling media such as air, water and nitrogen regardless of whether the cooling medium is steam. Also in the above, it is possible to provide a highly reliable cooling medium recovery type gas turbine by using the rotor blade and the rotor shaft having the structure of the present invention.

[0035]

As described above, according to the present invention, even if the flow passage of the cooling medium is provided so as to penetrate the joint surface between the rotor blade and the rotor shaft, the leakage of the cooling medium is prevented. In addition, it is possible to obtain this type of gas turbine that does not cause performance deterioration of plant efficiency and reliability of the gas turbine itself due to steam leakage.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view showing an embodiment of a gas turbine of the present invention.

2 is a plan view of a rotor shaft joint surface of FIG. 1. FIG.

FIG. 3 is a longitudinal sectional view of an essential part showing a gas turbine rotor blade and a rotor shaft body of the present invention during gas turbine operation.

FIG. 4 is a longitudinal sectional view of a main part showing another embodiment of the gas turbine blade and the rotor shaft body of the present invention.

5 is a top view of the rotor shaft joint surface of FIG. 4. FIG.

FIG. 6 is a longitudinal cross-sectional view of a main part showing a situation in which a gas turbine rotor blade according to another embodiment of the present invention shown in FIG. 4 is inserted into a rotor shaft body when the rotor blade body is inserted into the rotor shaft body.

FIG. 7 is a longitudinal sectional view of a main part showing another embodiment of the gas turbine rotor blade and the rotor shaft body of the present invention.

8 is a top view of the rotor shaft joint surface of FIG. 7. FIG.

FIG. 9 is a partial side view of a conventional air-cooled gas turbine rotor blade and rotor shaft body.

FIG. 10 is a longitudinal sectional view of a main part of a conventional air-cooled gas turbine rotor blade and rotor shaft body.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Moving blade, 2 ... Moving blade dovetail portion, 3 ... Moving blade dovetail portion bottom surface, 4 ... Moving blade dovetail portion bottom surface, 7 ... Moving blade dovetail portion bottom surface, 8 ... Rotor shaft body, 9 ... Rotor shaft body dovetail portion, DESCRIPTION OF SYMBOLS 10 ... Moving blade cooling steam supply flow path, 11 ... Moving blade cooling steam inlet, 12 ... Moving blade cooling steam recovery flow path, 13 ... Moving blade cooling steam discharge port, 14 ... Rotor shaft cooling steam supply flow path, 15
... rotor shaft cooling steam supply port, 16 ... rotor shaft cooling steam recovery passageway, 17 ... rotor shaft cooling steam recovery port, 20 ...
Seal groove, 20b ... Seal groove, 21 ... Seal groove, 21b
... seal groove, 24 ... metal O ring, 25 ... metal O ring, 26 ... seal groove, 27 ... seal groove, 28 ... seal groove, 30 ... supply cooling steam, 32 ... recovery cooling steam, 33b
... Supply cooling air, 33c ... Supply cooling air, 41 ... Metal pin, 42 ... Metal pin, 43 ... Metal pin, 51 ... Moving blade insertion direction, 60 ... Centrifugal force acting on moving blade, 65 ... Gap, 65
a ... Gap, 65b ... Gap, 65c ... Gap, 67 ... Gap distance between joint of rotor blade dovetail bottom surface and rotor shaft body when blade is inserted, 70 ... Gradient, 80 ... Cooling air supply cavity, 81a ... Cooling air supply channel, 81b ... Cooling air supply channel.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication location F02C 7/28 F02C 7/28 Z (72) Inventor Kazuhiko Kawaike 7-2 Omika-cho, Hitachi City, Ibaraki Prefecture No. 1 Electric Power Company / Electric Machinery Development Division, Hitachi, Ltd.

Claims (7)

[Claims] 1. A gas turbine rotor shaft, and rotor blades arranged in parallel in the circumferential direction around the rotor shaft body and having a cooling medium flow passage therein, the cooling medium flow passage of the rotor blade. In a gas turbine in which a cooling medium supply / discharge passage for supplying / discharging a cooling medium is provided so as to penetrate through a joint surface between a moving blade and a rotor shaft body, and a joint surface between the moving blade and the rotor shaft body, and It is characterized in that a concave groove is provided around a supply / discharge passage that penetrates the joint surface, an elastically deformable member is arranged in the concave groove, and a step in the rotor axial direction is provided on the joint surface. gas turbine. 2. A gas turbine rotor shaft, and rotor blades arranged in parallel in the circumferential direction around the rotor shaft body and having a cooling medium flow passage therein, the cooling medium flow passage of the rotor blade. In a gas turbine in which a cooling medium supply path for supplying a cooling medium to and a cooling medium discharge path for discharging the cooling medium from the cooling medium flow path are provided so as to penetrate the joint surface between the rotor blade and the rotor shaft, A cooling medium supply passage and a cooling medium discharge passage are provided side by side in the rotor axial direction at the joint surface portion between the rotor blade and the rotor shaft, and the joint surface between the rotor blade and the rotor shaft body has a step in the rotor axial direction. And a concave groove is provided around the cooling medium supply passage and the cooling medium discharge passage on the joint surface, and an elastically deformable member is arranged in each concave groove. gas turbine. 3. The gas turbine according to claim 1, wherein a cooling medium supply passage and a cooling medium passage at a joint surface portion between the rotor blade and the rotor shaft body are provided on surfaces having different steps. 4. A gas turbine rotor shaft, and rotor blades arranged in parallel in the circumferential direction around the rotor shaft body and having a cooling medium passage therein. In a gas turbine in which a cooling medium supply path for supplying a cooling medium to and a cooling medium discharge path for discharging the cooling medium from the cooling medium flow path are provided so as to penetrate the joint surface between the rotor blade and the rotor shaft, A cooling medium supply path and a cooling medium discharge path are provided side by side in the rotor axial direction at the joint surface portion between the rotor blade and the rotor shaft, and the joint surface between the rotor blade and the rotor shaft body is arranged with respect to the insertion direction of the rotor blade. ,
In addition to forming it with a gradient, concave grooves are provided around the cooling medium supply passage and the cooling medium discharge passage on the joint surface, and elastically deformable members are arranged in the respective concave grooves. Characteristic gas turbine. 5. The concave groove in the joint surface is provided in the joint surface on the rotor shaft side.
The described gas turbine. 6. The gas turbine according to claim 1, 2, 3, 4, or 5, wherein the elastically deformable member is a metal O-ring. 7. The gas turbine according to claim 1, 2, 3, 4, or 5, wherein the elastically deformable member is a rod-shaped metal pin.