JP2003004149A - Shaft seal mechanism and gas turbine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shaft seal mechanism capable of reducing an amount of leakage through a space between division parts and alloying a difference in thermal expansion between a shaft seal mechanism and its mounting part and a gas turbine having the mechanism. SOLUTION: The gas turbine adapts constitution that a joining member 41 to apply flow passage resistance on combustion gas G flowing in the axial direction through a space between division parts is situated between the division parts 40.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shaft seal mechanism suitable for use as a rotary shaft of a large fluid machine such as a gas turbine, a steam turbine, a compressor, a water turbine, a refrigerator, a pump or the like. The present invention also relates to a gas turbine that guides high-temperature and high-pressure gas to a turbine to expand the gas and converts the thermal energy of the gas into mechanical rotational energy to generate power, and particularly to a shaft seal applied to the rotating shaft thereof. Regarding the mechanism.

[0002]

2. Description of the Related Art Conventionally, in a rotary shaft of a fluid machine or the like, it has been a main purpose to prevent a working fluid from leaking from a high pressure side to a low pressure side through an annular gap between a stationary side and a rotating side. A shaft seal mechanism is used for this purpose. The shaft seal mechanism includes a labyrinth seal and a brush seal, each of which has a structure described below.

First, the labyrinth seal shown in FIG.
It is arranged and fixed so as to fill the annular space that is the gap between the stationary side 1 and the rotating side 2, and by narrowing the gap 4 between the rotating side 2 and the fins 3, it flows from the high pressure side 5 to the low pressure side 6. The flow passage area of the fluid is reduced, and the flow passage 7 having a large pressure loss resistance is formed. Such a configuration serves to reduce the flow rate of fluid that leaks from the high pressure side 5 to the low pressure side 6. Similarly, FIG.
The brush seal shown in FIG. 1 is also arranged and fixed so as to fill the annular space which is the gap between the stationary side 1 and the rotating side 2, and the wire side 7A is brought into contact with the rotating side 2 to fix the stationary side 1 By eliminating the gap between the rotating side 2 and the rotating side 2, and only allowing the substantial flow path 7B to pass between the wire tips 7A, the flow rate of the fluid leaking from the high pressure side 5 to the low pressure side 6 is significantly increased. It is possible to reduce to.

An example of the overall construction of the shaft seal mechanism as viewed from the front with reference to this brush seal is shown in FIG.
It shows in (b). Note that FIG. 22A shows a view A in FIG.
FIG. 22B is a front view seen further, and FIG.
It is a BB arrow line view of. As shown in FIGS. 22 (a) and 22 (b), the brush seal is divided at a plurality of positions in the circumferential direction (the figure shows an example of 6 divisions),
A gap 9 is formed in each of these divided portions. When the working fluid of the fluid machine is accompanied by a temperature change, these gaps 8 are made of different materials for the shaft seal mechanism and the mounting member,
Alternatively, it is essential in order to allow a difference in thermal expansion due to a difference in transitional temperature change.

[0005]

However, in such a divided structure, gaps 9 are formed between the respective divided pieces 8, and these gaps 9 are fluidized linearly from the high pressure side 5 to the low pressure side 6. Since the flow path 10 for passing the gas is formed, the amount of leakage that leaks through the flow path 10 having a low flow resistance increases, which causes a problem that the mechanical efficiency of the gas turbine is reduced. It will be. This problem can occur in all shaft seal mechanisms having the same divided structure, and is not limited to brush seals,
It can also be a problem with labyrinth seals.

The present invention has been made in view of the above circumstances, and reduces the amount of leakage from each divided portion, and
An object of the present invention is to provide a shaft seal mechanism capable of allowing a difference in thermal expansion between the shaft seal mechanism and a mounting portion thereof, and a gas turbine including the shaft seal mechanism.

[0007]

The present invention adopts the following means in order to solve the above problems. That is, the shaft seal mechanism according to claim 1 of the present invention blocks fluid flowing in the axial direction of the rotary shaft through the annular space between the rotary shaft and the stationary portion, and is viewed from the front in the axial direction. In this case, in a ring-shaped shaft seal mechanism divided into a plurality of divided portions in the circumferential direction, a flow path resistance is imparted to the fluid flowing in the axial direction between the divided portions. A channel resistance forming portion is provided. Further, the shaft sealing mechanism according to claim 2 is the shaft sealing mechanism according to claim 1, wherein the flow path resistance forming portion is a first covering member that covers between the facing divided portions. To do. The shaft seal mechanism according to claim 3 is
The shaft seal mechanism according to claim 1, wherein the flow path resistance forming portion includes a convex portion protruding from each of the facing divided portions in a direction approaching each other, and a second covering member covering the convex portion. It is characterized by

According to the shaft seal mechanism of any one of claims 1 to 3, the flow path resistance by the flow path resistance forming portion is given to the fluid which leaks through between the divided portions. Therefore, pressure loss is likely to occur, and leakage can be prevented more easily than in the case of passing through a linear clearance channel as in the related art. Moreover, since the divided portions are kept separated from each other, they can be moved toward and away from each other, which allows the ring-shaped shaft seal member to expand its outer diameter without stress. It can also be contracted.

According to a fourth aspect of the present invention, there is provided the shaft sealing mechanism according to the third aspect, wherein the second covering member has a continuous outer shape between the divided portions facing each other from one to the other. It is characterized in that it has an outer shape that is connected so that According to the shaft seal mechanism of the fourth aspect, since the entire outer shape is a simple ring shape continuous in the circumferential direction, the second cover portion is provided to the stationary portion to which each divided portion is attached. It does not require additional processing for placement.

According to a fifth aspect of the present invention, there is provided the shaft sealing mechanism according to the first aspect, wherein the flow path resistance forming portion is an uneven fitting portion provided between the divided portions facing each other. It is characterized by According to the shaft seal mechanism of the fifth aspect, the flow path resistance is imparted to the fluid attempting to leak through the respective divided parts by the concave-convex fitting part that is the flow path resistance forming part. , Susceptible to pressure loss,
Leakage can be prevented more easily than in the case of passing through a linear clearance channel as in the related art. Moreover, since the divided portions are kept separated from each other, they can be moved toward and away from each other, which allows the ring-shaped shaft seal member to expand its outer diameter without stress. It will also be possible to contract.

A gas turbine according to a sixth aspect of the present invention introduces a high-temperature and high-pressure gas into a casing, and blows it onto the rotor blades of a rotating shaft rotatably supported inside the casing to generate thermal energy of the gas. In a gas turbine that converts power into mechanical rotational energy to generate power,
A shaft seal mechanism according to any one of claims 1 to 5 is provided. According to the gas turbine described in claim 6, it is possible to obtain the same operation as that of the shaft seal mechanism described in any of claims 1 to 5.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Each embodiment of a shaft seal mechanism and a gas turbine equipped with the same according to the present invention will be described below. However, it goes without saying that the present invention is not limited to these embodiments. Is.

First, the first embodiment will be described with reference to FIGS. FIG. 1 shows a schematic configuration of a gas turbine. In the figure, reference numeral 20 indicates a compressor, reference numeral 21 indicates a combustor, and reference numeral 22 indicates a gas turbine.
The compressor 20 takes in a large amount of air inside and compresses it. Usually, in a gas turbine, a part of the power obtained by a rotary shaft 23, which will be described later, is used as the power of the compressor. The combustor 21 mixes fuel with the air compressed by the compressor 20 and burns it. The turbine 22 introduces the combustion gas generated in the combustor 21 into the turbine 22 and expands the combustion gas, and a rotor blade 23 provided on the rotating shaft 23.
By spraying on e, the thermal energy of the combustion gas is converted into mechanical rotational energy to generate power.

The turbine 22 is provided with a plurality of stationary blades 24a fixed to the casing 24 side in addition to a plurality of moving blades 23e on the rotating shaft 23 side. They are arranged alternately in the axial direction of the rotary shaft 23. The rotor blade 23e receives the pressure of the combustion gas flowing in the axial direction of the rotary shaft 23, rotates the rotary shaft 23, and the rotational energy applied to the rotary shaft 23 is extracted from the shaft end and used. There is. A leaf seal 25 is provided between the stationary blade 24a and the rotary shaft 23 as a shaft seal mechanism for reducing the amount of combustion gas leaking from the high pressure side to the low pressure side.
Is provided.

As shown in FIGS. 2 and 3, the leaf seal 25 has a width in the axial direction of the rotary shaft 23, and its tip slides on the peripheral surface 23a of the rotary shaft 23 to leave a gap 30 therebetween. A plurality of flexible thin plates 29 whose outer peripheral side ends are brazed and fixed to the inner peripheral surface of the leaf seal casing 24A.
Are multiply provided in the circumferential direction of the rotary shaft 23 so that the outer circumference of the rotary shaft 23 can be sealed, and each thin plate 29 and the circumferential surface 23a of the rotary shaft 23 form an acute angle, and both thin plate 29 both sides in the rotary shaft direction. A low-pressure side plate 26 and a high-pressure side plate 27 are provided in each. And this leaf seal 25
Is the flow of the combustion gas G (fluid) leaking in the axial direction of the rotary shaft 23 through the annular gap space (annular space) between the leaf seal 25 (stationary portion) and the peripheral surface 23a of the rotary shaft 23. This is a ring shape that is divided (six divisions) into a plurality of (six) divisions 40 in the circumferential direction when viewed from the front in the axial direction.

Each thin plate 29 has a flat plate shape having a predetermined width in the axial direction of the rotary shaft 23, and has a structure of being arranged in multiple layers in the circumferential direction of the rotary shaft 23. By sealing the outer circumference of the rotary shaft 23, the space around the rotary shaft 23 is partitioned into a high pressure side region and a low pressure side region. Further, on both sides in the width direction of each thin plate 29, the high-pressure side plate 27 is arranged in the high-pressure side region, and the low-pressure side plate 26 is arranged in the low-pressure region as guide plates in the pressure acting direction.

Then, the leaf seal 25 of the present embodiment.
As shown in FIGS. 2 to 4, between the divided portions 40, which face each other as flow passage resistance forming portions that give flow passage resistance to the combustion gas G that extends in the axial direction between them. Joining member 41 (first covering member) that covers between the divided portions 40
The point that is provided is particularly characteristic. This joining member 4
1 is an end portion 40a of one of the divided portions 40 and the end portion 40a
End 40b of the other divided portion 40 facing each other and a predetermined dimension (for example, 0.
It is a gate-shaped part that covers the clearance c1 of about 1 mm to 1 mm) and can cover the joint part between the divided parts 40 except the inner peripheral side part of each divided part 40 provided with each thin plate 29. It is possible.

That is, as shown in FIG. 5, each of the joining members 41 is a portion of the joining portion between the divided portions 40, which overlaps the side surfaces 40c and 40d facing the high-pressure side area and the low-pressure side area, and the above-mentioned portion. A pair of side walls 41a, 4 covering the gap c1
1b, a portion overlapping each outer peripheral surface 40e, and the gap c1.
And an outer peripheral wall 41c that covers the. Further, as shown in the figure, both side walls 41a, 4 of each joining member 41 are
1b is formed with stepped locking portions 41a1 and 41b1 that lock with stepped locked portions 40c1 and 40d1 formed on the side surfaces 40c and 40d of the split portions 40, respectively. It is possible to prevent each joining member 41 from coming off in the radial direction of the leaf seal 25. In addition,
As the clearance c2 between each side wall 41a, 41b and each side surface 40c, 40d, a dimension (c2) which is 1/2 or less of the clearance c1.
It is preferable to adopt <0.5 × c1), and in some cases, sliding contact (c2 = 0) may be performed.

The leaf seal 25 of this embodiment described above
According to the above, since the flow resistance of each joining member 41 is imparted to the combustion gas G which is about to leak out between the respective divided portions 40, the combustion gas G is likely to be subjected to the pressure loss and the straight line as in the conventional case. It is possible to prevent the gas from leaking more easily as compared with the case where the gas flows through the general clearance passage, and it is possible to improve the mechanical efficiency of the gas turbine.

That is, as shown in FIG. 4, the combustion gas G which is about to leak from the high pressure side region toward the low pressure side region.
The leakage amount can be reduced for the following reasons (1) to (3). (1) Since it has to pass through a detour path that is complicatedly bent so as to bend at four points a, b, c, and d, pressure loss increases and it becomes difficult to leak. (2) In addition to the flow path of the clearance c1, the entire flow path length is increased by the flow path of the clearance c2, so that the pressure loss also increases and the leakage becomes difficult. (3) Since the passage of the gap c2 that is narrower than the gap c1 has to be passed, the area of the passage is narrowed at this portion, and the pressure loss also increases and the leakage becomes difficult.

Moreover, the respective divided portions 40 are kept separated from each other with the gaps c1 between them, and
Since the joining members 41 do not restrain the divided portions 40 from each other, they can move toward and away from each other.
The ring-shaped leaf seal 25 can also expand or contract its outer diameter dimension without causing stress.

As described above, in the leaf seal 25 of this embodiment, the joining members 41 for imparting flow path resistance to the combustion gas G extending between the divided portions 40 in the axial direction are provided between the divided portions 40. The configuration provided is adopted. According to this configuration, by the flow path resistance given by each joining member 41,
It is possible to reduce the flow rate of the combustion gas G that leaks between the divided portions 40. Moreover, since the divided portions 40 are kept in a separated state, the thermal expansion difference between the leaf seal 25 and its mounting portion may be allowed by the approaching / separating operation between these dividing portions 40. It is possible.

The joining member 41 of the present embodiment is different from the inner peripheral side portion of each divided portion 40 provided with each thin plate 29.
Although the joint portion between the divided portions 40 is covered, the present invention is not limited to this. For example, as shown in FIG. 6, the inner peripheral surface side of the low-pressure side plate 26 and the high-pressure side plate 27 (the surface of the rotary shaft 23). It is also possible to adopt a shape that also covers the surface on the side to be processed. In this case, as shown in the same figure, since the joining member 41 can prevent the leakage of the combustion gas G from the outer peripheral side toward the inner peripheral side where the rotary shaft 23 is located, the leakage amount can be further reduced. It becomes possible to further improve the mechanical efficiency of the gas turbine.

Next, a second embodiment of the present invention will be described with reference to FIGS. 7 to 10. The characteristic part will be mainly described, and the other parts are the same as those of the first embodiment. Description of parts is omitted. As shown in FIGS. 7 to 9, the leaf seals 50 of the present embodiment (provided that a new reference numeral 50 is provided to distinguish them from the leaf seals 25) approach each other from between the facing divided portions 40. A particular feature is that each convex portion 51 projecting in each direction and the joining member 52 (second covering member) that covers these convex portions 51 are adopted as the flow path resistance forming portion.

Each convex portion 51 has an outer shape in which the outer shape of each divided portion 40 is made similar to each other, and is formed integrally with each divided portion 40. Then, as one side wall of each convex portion 51, a low-pressure side plate 26 that is continuous with the low-pressure side plate 26 of each dividing part 40, and as another side wall, a high-pressure side plate 27 that is continuous with the high-pressure side plate 27 of each dividing part 40 is formed. ing. Each joining member 52 has a convex portion 51 of one divided portion 40, a convex portion 51 of the other divided portion 40 facing the convex portion 51, and a predetermined dimension (for example, 0 .1 mm to 1 m
It is a gate-shaped component that covers the clearance c1 of about m), and can cover each convex portion 51 except the inner peripheral side portion of each convex portion 51 provided with each thin plate 29. .

That is, as shown in FIG. 10, each joining member 52 covers a portion of each convex portion 51, which overlaps the side surfaces 51a and 51b facing the high-pressure side area and the low-pressure side area, and the gap c1. It is configured to include a pair of side walls 52a and 52b and an outer peripheral wall 52c that covers a portion overlapping each outer peripheral surface 51c and the gap c1. Further, as shown in the figure, the side walls 52a, 52b of each joining member 52 are locked to the stepped locked portions 51a1, 51b1 formed on each side surface 51a, 51b of each convex portion 51. The step-like locking portions 52a1 and 52b1 are formed to prevent the joining members 52 from coming off in the radial direction of the leaf seal 50. In addition, each side wall 52a, 5
The clearance c3 between the 2b and each side surface 51a, 51b is not more than half the clearance c1 (c3 <0.5 × c1).
Is preferable, and in some cases, sliding contact (c3 =
0) may be performed.

Further, as shown in FIGS. 8 and 9, each joining member 52 has an outer shape in which the outer shape between the divided portions 40 facing each other is continuously connected from one side to the other side. . That is, each side wall 52 of each joining member 52
The shapes of a and 52b, which respectively face the low-pressure side area and the high-pressure side area, are the same as the shapes of both side surfaces of the respective divided portions 40 on both sides thereof, and are continuous.

The leaf seal 50 of this embodiment described above
According to the above, since the flow path resistance due to the respective convex portions 51 and the respective joint members 52 is imparted to the combustion gas G which is about to leak through between the respective divided portions 40, it is easy to receive the pressure loss, As compared with the case of passing through such a linear clearance flow path as described above, leakage can be prevented more easily, and the mechanical efficiency of the gas turbine can be improved. The reason why the leakage amount of the combustion gas G can be reduced is the same as the above-mentioned reasons (1) to (3), but in the present embodiment, as shown in FIG.
Since a new flow path for the gap c4 is further provided,
Compared with the leaf seal 25 of the embodiment, the pressure loss is further increased and it is more difficult to leak.

The leaf seal 50 of this embodiment described above
According to the first embodiment, as in the first embodiment, the flow rate of the combustion gas G that leaks between the divided portions 40 can be reduced, and the difference in thermal expansion between the leaf seal 25 and its attachment portion can be reduced. It is also possible to allow. further,
The leaf seal 50 of the present embodiment has the respective joining members 52.
Has an outer shape in which the outer shape between the divided portions 40 facing each other is continuously connected from one side to the other side, so that only the location of each joining member 52 is special with respect to the mounting portion of the leaf seal 50. It can be said that it is more preferable because it is not necessary to perform various processes, the assembling property is improved, and the processing cost can be reduced.

The joining member 52 of the present embodiment covers the space between the convex portions 51 except the inner peripheral side portion of the convex portions 51 provided with the thin plates 29, but is not limited to this. For example, as shown in FIG. 11, the low-pressure side plate 26 and the high-pressure side plate 2
A shape that covers the inner peripheral surface side of 7 may also be adopted. In this case, as shown in the figure, even if the leakage of the combustion gas G from the outer peripheral side toward the inner peripheral side where the rotary shaft 23 is located, the joining member 5
Therefore, it is possible to reduce the amount of leakage and further improve the mechanical efficiency of the gas turbine.

Next, a third embodiment of the present invention will be described with reference to FIGS. 12 to 15. The characteristic part will be mainly described, and the other parts are the same as those of the first embodiment. Description of parts is omitted. As shown in FIGS. 12 to 14, the leaf seals 60 of the present embodiment (provided with a new reference numeral 60 to be distinguished from the leaf seals 25) are divided portions 40 facing each other.
A particular feature is that the concave-convex fitting portion 61 provided therebetween is used as the flow path resistance forming portion. That is, the concave-convex fitting portion 61 is provided with the convex portion 6 provided so as to project from one of the facing divided portions 40 toward the other.
2 and the convex portion 62 so as to cover them, and the other split portion 4
0 and a concave portion 63 (fitting portion).

The convex portion 62 has an outer shape in which the outer shape of each divided portion 40 is thinned in a similar shape, and is integrally formed with each divided portion 40. Then, as one side wall of each convex portion 62,
Low-pressure side plate 2 continuous with the low-pressure side plate 26 of each divided portion 40
6. As the other side wall, a high-pressure side plate 27 that is continuous with the high-pressure side plate 27 of each dividing portion 40 is formed. As shown in FIG. 14, the recess 63 has a gap c1 of a predetermined dimension (for example, about 0.1 mm to 1 mm) in the circumferential direction in a state where the projection 62 is fitted into the recess 63 and assembled. It is formed at the end of the divided portion 40 so as to be secured, and it is possible to cover the periphery of the convex portion 62 except for the inner peripheral side portion of the convex portion 62 where each thin plate 29 is provided.

Further, as shown in FIG. 15, in the concave portion 63, a step-like engagement for engaging with the step-like engaged portions 62a1, 62b1 formed on the respective side surfaces 62a, 62b of the projection 62. The portions 63a1 and 63b1 are formed, and it is possible to prevent the fitted state between the concave portion 63 and the convex portion 62 from coming off in the radial direction of the leaf seal 50. As the gap c5 between the concave portion 63 and the convex portion 62, it is preferable to adopt a dimension (c5 <c1) which is equal to or smaller than the gap c1 and may be slidably contacted (c5 = 0) in some cases.

The leaf seal 60 of this embodiment described above
According to the above, since the flow path resistance due to the concave-convex fitting portion 61 is imparted to the combustion gas G which is about to leak through between the divided portions 40, pressure loss is likely to occur, and the combustion gas G as in the conventional case is obtained. Leakage can be prevented more easily than in the case of passing through a linear clearance flow path, and the mechanical efficiency of the gas turbine can be improved. Therefore, according to the leaf seal 60 of the present embodiment, it is possible to reduce the flow rate of the combustion gas G that leaks between the divided portions 40, as in the first embodiment, and yet the leaf seal 60 and its It is also possible to allow a difference in thermal expansion with the mounting portion.

Furthermore, the leaf seal 60 of this embodiment.
In comparison with the first embodiment, it is not necessary to manufacture a separate component such as the joining member 41, and the outer shape between the divided portions 40 facing each other is continuous from one to the other. Since the outer shape of the leaf seal 60 is formed as described above, it is not necessary to perform special processing on the mounting portion of the leaf seal 60 only at the concave-convex fitting portion 61, so that the assemblability is improved and the processing cost is reduced. It is possible to say that it is more preferable.

The concave portion 63 of this embodiment is formed by each thin plate 2.
Although the circumference of each convex portion 62 is covered except for the inner peripheral side portion of each convex portion 62 where 9 is provided, the present invention is not limited to this. For example, as shown in FIG. Side plate 2
A shape that covers the inner peripheral surface side of 7 may also be adopted. In this case, as shown in the same figure, the leakage of the combustion gas G from the outer peripheral side toward the inner peripheral side where the rotary shaft 23 is located can also be blocked by the recess 63, so that the leakage amount can be further reduced.
It is possible to further improve the mechanical efficiency of the gas turbine.

As a modified example of the concave-convex fitting portion 61 of this embodiment, for example, there are those shown in FIGS. 17 to 19, but it goes without saying that other concave-convex fitting shapes may be adopted.
In addition, in these modified examples, the case where the present invention is applied to the brush seal having the brush 70 is described as an example. That is, the concavo-convex fitting portion 61 of the modified example shown in FIG. 17 is formed at the end portion of one of the divided portions 40 with the square convex portion 71 and the square concave portion 72, and at the end portion of the other divided portion 40. The square convex portion 73 and the square concave portion 74 are meshed with each other so as to secure a gap c1 having a predetermined dimension (for example, about 0.1 mm to 1 mm).

Similarly, the concavo-convex fitting portion 61 of the modified example shown in FIG. 18 has a triangular convex portion 81 and a triangular concave portion 82 formed at the ends of one of the divided portions 40, and the other divided portion. Four
The triangular convex portion 83 and the triangular concave portion 84 formed at the end portion of 0 have a predetermined size (for example, 0.1 mm to 1 mm).
It is configured by meshing with each other so as to secure a clearance c1 of about (about). Further, the uneven fitting portion 61 of the modified example shown in FIG. 19 has a meshing surface between the low-pressure side plates 26 and a meshing surface between the high-pressure side plates 27, which are linear in FIG. Is an example in the case of being configured in a triangular concavo-convex shape.

Also in each of the modified examples of FIGS. 17 to 19 described above, it is possible to obtain the same operation and effect as those of the above-described third embodiment, and the bypass in which the flow path of the combustion gas G flows is further complicated. Since it becomes a passage, it is possible to give a larger flow path resistance to the combustion gas G passing therethrough.
It is possible to further reduce the leakage amount of.

The shaft seal mechanism of the present invention and the first to third embodiments of the gas turbine equipped with the shaft seal mechanism and various modifications thereof have been described above. The gas turbine uses combustion gas. In addition to a general gas turbine that rotates a turbine shaft to obtain power, it can also be applied to an aircraft gas turbine engine or the like. Further, the gas turbine according to the present invention can be diverted to a fluid machine such as a steam turbine using steam. Further, the shaft seal mechanism according to the present invention can be applied to various fluid machines such as a gas turbine, a gas turbine engine, and a steam turbine.

Although each leaf seal 40, 50, 60 has a six-divided structure, the present invention is not limited to this, and a structure of five or less, or seven or more may be adopted. Further, in the present embodiment, the case where the present invention is applied to the leaf seals 40, 50, 60 having the respective thin plates 29 has been described as an example, but the present invention is not limited to this, and a split structure such as a brush seal and a labyrinth seal is provided. It is needless to say that the present invention may be applied to the shaft seal mechanism of No.

[0042]

The shaft seal mechanism according to the first to third aspects of the present invention provides a flow passage resistance forming portion for imparting flow passage resistance to the fluid flowing in the axial direction between the divided portions. Is adopted. According to this configuration, it is possible to reduce the flow rate of the fluid that leaks between the divided parts due to the resistance given by the flow path resistance forming part. Furthermore, since the separated portions are maintained in a separated state, it is possible to allow a difference in thermal expansion between the shaft seal mechanism and its mounting portion by the approaching and separating operations between these divided portions. Become.

Further, the shaft seal mechanism according to claim 4 is
In the shaft seal mechanism according to a third aspect of the present invention, the second cover member has an outer shape in which the outer shapes of the divided portions facing each other are continuous from one side to the other side. According to this configuration, it is not necessary to perform additional processing for disposing the second cover portion on the stationary portion to which each divided portion is attached, so that it is possible to prevent an increase in processing cost.

Further, the shaft seal mechanism according to claim 5 is
The configuration in which the concavo-convex fitting part is provided between the divided parts is provided as a flow path resistance forming part that gives flow path resistance to the fluid flowing between them in the axial direction. According to this configuration, it is possible to reduce the flow rate of the fluid that leaks between the divided portions due to the resistance provided by the concave-convex fitting portion. Furthermore, since the separated portions are maintained in a separated state, it is possible to allow a difference in thermal expansion between the shaft seal mechanism and its mounting portion by the approaching and separating operations between these divided portions. Become.

A gas turbine according to a sixth aspect of the present invention adopts a configuration including the shaft seal mechanism according to any of the first to fifth aspects. According to this configuration, the amount of leakage from each divided portion is reduced to improve the mechanical efficiency, and
It is possible to allow a difference in thermal expansion between the shaft seal mechanism and its mounting portion.

[Brief description of drawings]

FIG. 1 is a schematic overall configuration cross-sectional view showing a first embodiment of a gas turbine provided with a shaft seal mechanism according to the present invention.

FIG. 2 is a view showing a coaxial seal mechanism of the same gas turbine, and is a view taken along the line CC of FIG.

FIG. 3 is a view showing a main part of the coaxial seal mechanism, and is a perspective view of a D part in FIG. 2.

FIG. 4 is a view showing the main part of the coaxial seal mechanism,
It is a EE arrow line view of FIG.

FIG. 5 is a view showing the main part of the coaxial seal mechanism,
FIG. 5 is a sectional view taken along line FF of FIG. 4.

FIG. 6 is a view showing a modified example of the coaxial seal mechanism,
FIG. 6 is a partially enlarged view corresponding to a G part in FIG. 5.

FIG. 7 is a view showing a second embodiment of the shaft seal mechanism of the present invention, and is a perspective view of relevant parts corresponding to FIG. 3.

FIG. 8 is a view showing the main part of the coaxial seal mechanism,
It is the front view seen from the arrow H of FIG.

FIG. 9 is a view showing the main part of the coaxial seal mechanism,
FIG. 9 is a view on arrow I-I of FIG. 8.

10 is a view showing the main part of the coaxial seal mechanism and is a cross-sectional view taken along line JJ of FIG.

FIG. 11 is a view showing a modified example of the coaxial seal mechanism, and is a partially enlarged view corresponding to a K portion in FIG.

FIG. 12 is a view showing a third embodiment of the shaft seal mechanism of the present invention, and is a perspective view of relevant parts corresponding to FIG. 3.

13 is a view showing the same main part of the coaxial seal mechanism, and is a front view seen from an arrow L in FIG.

FIG. 14 is a view showing the main part of the coaxial seal mechanism and is a view taken along the line MM in FIG. 13.

15 is a view showing the same main part of the coaxial seal mechanism, which is a sectional view taken along line NN of FIG.

16 is a view showing a modified example of the coaxial seal mechanism, and is a partial enlarged view corresponding to the portion O in FIG.

17 is a view showing another modification of the coaxial seal mechanism, and is a partially enlarged view corresponding to FIG. 4. FIG.

FIG. 18 is a view showing another modification of the coaxial seal mechanism, and is a partially enlarged view corresponding to FIG. 4.

FIG. 19 is a view showing another modification of the coaxial seal mechanism, and is a partially enlarged view corresponding to FIG. 4.

FIG. 20 is a view showing a labyrinth seal which is an example of a conventional shaft seal mechanism, and is a cross-sectional view seen from a cross-section including an axis of a rotating shaft.

FIG. 21 is a view showing a brush seal which is another example of the conventional shaft seal mechanism, and is a cross-sectional view seen from a cross-section including the axis of the rotating shaft.

FIG. 22 is a view showing the brush seal, showing (a).
Is a front view seen from the arrow A of FIG. 21, and (b) is a view taken along the line BB of (a).

[Explanation of symbols]

22 ... Gas turbine 23 ... Rotating shaft 23e ... Moving blade 24 ... Casing 25, 50, 60 ... Leaf seal (shaft seal mechanism) 40 ... Dividing part 41 ... Joining member (Flow path resistance forming portion, first covering member) 51, 52 ... Convex portion, joining member (convex portion, second covering member,
Flow path resistance forming part) 61 ... concave-convex fitting part G ... combustion gas (fluid, gas)

Continued front page    (72) Inventor Koichi Akagi             2-1-1 Niihama, Arai-cho, Takasago, Hyogo Prefecture             Takasago Works, Mitsubishi Heavy Industries, Ltd. (72) Inventor, Masanori Yuri             2-1-1 Niihama, Arai-cho, Takasago, Hyogo Prefecture             Takasago Works, Mitsubishi Heavy Industries, Ltd. F-term (reference) 3G002 HA02                 3J042 AA04 AA11 BA03 CA10 DA11

Claims (6)

[Claims] 1. A plurality of divided parts in a circumferential direction when a fluid flowing in an axial direction of the rotary shaft is blocked through an annular space between the rotary shaft and a stationary part, when viewed from the axial direction in a front view. In the ring-shaped shaft seal mechanism divided into, the flow path resistance forming portion that provides flow path resistance to the fluid flowing in the axial direction between the split portions is provided between the split portions. A shaft seal mechanism characterized in that 2. The shaft seal mechanism according to claim 1, wherein the flow path resistance forming portion is a first covering member that covers between the facing divided portions. 3. The shaft seal mechanism according to claim 1, wherein the flow path resistance forming portion projects from the facing divisional portions in respective directions approaching each other, and a second portion covering the projections. A shaft seal mechanism comprising: a cover member. 4. The shaft seal mechanism according to claim 3, wherein the second covering member has an outer shape that connects the outer shapes of the divided portions facing each other so as to be continuous from one side to the other side. A shaft seal mechanism characterized by. 5. The shaft seal mechanism according to claim 1, wherein the flow path resistance forming portion is an uneven fitting portion provided between the divided portions facing each other. 6. A high temperature and high pressure gas is introduced into a casing,
A gas turbine that converts the thermal energy of the gas into mechanical rotational energy to generate power by spraying on the rotor blades of a rotating shaft that is rotatably supported inside the casing. A gas turbine comprising the shaft sealing mechanism according to claim 1.