JP2002013647A - Shaft sealing mechanism and gas turbine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shaft sealing mechanism, capable of reducing the leakage amount of a gas from a high pressure side to a low pressure side and having superior abrasion resistance, and to provide a gas turbine having the shaft sealing mechanism. SOLUTION: In this shaft-sealing mechanism, a leaf seal 25 with a clearance adjustment for making a clearance at low pressure side 31 to be larger than a clearance at high pressure side 32, is applied as a gas pressure adjusting means for adjusting the gas pressure to be added to a lower face 29b higher than the gas pressure to be added to an upper face 29a at tan arbitrary position along the cross section of a thin plate 29. In this gas turbine, the constitution including the leaf seal 25 is adopted.

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 rotating shaft of a large fluid machine such as a gas turbine, a steam turbine, a compressor, a water turbine, a refrigerator, a pump, and the like. The present invention also relates to a gas turbine that guides a high-temperature and high-pressure gas to a turbine and expands the gas to convert the heat energy of the gas into mechanical rotational energy to generate power, and in particular, a shaft seal mechanism applied to a rotary shaft thereof. About.

[0002]

2. Description of the Related Art In a gas turbine, a shaft seal mechanism is provided between a stationary blade and a rotating shaft to reduce the amount of combustion gas leaking from a high pressure side to a low pressure side. As this shaft seal mechanism, a non-contact labyrinth seal has been widely used conventionally. By the way, in this labyrinth seal, since the gap at the fin tip must be increased to some extent so that the gap at the fin tip does not come into contact even during shaft vibration during transient rotation or transient thermal deformation,
Gas leakage is large. Instead of such a labyrinth seal, there is a brush seal as a seal material developed to reduce the amount of leakage.

FIGS. 16A and 16B are schematic diagrams of a brush seal of this type. In the figure, reference numeral 1 denotes a rotating shaft, reference numeral 2 denotes a casing, reference numeral 3 denotes a low-pressure side plate, and reference numeral 4
Is a high-pressure side plate, 5 is a brazing portion, and 6 is a wire. The wire 6 is composed of a filament having an appropriate rigidity and a wire diameter of 50 to 100 μm so as to absorb eccentricity due to vibration of the rotating shaft 1 or thermal deformation.
There is a dense bundle with a width of 3 to 5 mm so that there is no gap between them. The wire 6 is attached at an angle to the rotation direction so as to form an acute angle with the outer periphery of the rotating shaft 1. The distal end of the wire 6 is in contact with the outer periphery of the rotary shaft 1 with a predetermined preload, and the contact reduces the amount of leakage in the axial direction.

[0004] The wire 6 slides in contact with the rotating shaft 1 and generates heat under atmospheric conditions or peripheral speeds and becomes a red-hot state. I have. Since the sliding surface of the outer periphery of the rotary shaft 1 is worn together with the wire 6, the sliding surface of the rotary shaft 1 is coated with a wear-resistant material. further,
Since the wire 6 has a small rigidity in the axial direction of the rotary shaft 1, breakage of the wire 6 is prevented by making the inner diameter of the low-pressure side plate 3 substantially equal to the outer circumference of the rotary shaft 1.

In addition, a leaf seal 10 as shown in FIG. 17, for example, has been developed. As shown in FIG. 1, the leaf seal 10 includes a flat thin plate 18 having a predetermined width dimension in the axial direction of the rotary shaft 11.
1 are arranged in multiple layers in the circumferential direction. These thin plates 18 are brazed (brazed portions 15) only at the base end on the outer peripheral side in the casing 12. It is divided into side areas. In addition, thin plate 1
On both sides of 8, a high-pressure side plate 14 is mounted on the high-pressure side region, and a low-pressure side plate 13 is mounted on the low-pressure side region as a guide plate in the direction of pressure action.

The thin plate 18 is designed to have a predetermined rigidity determined by the thickness in the axial direction of the rotating shaft 11. Also,
The thin plate 18 is attached to the casing 12 so that an angle between the thin plate 18 and the peripheral surface of the rotary shaft 11 is acute with respect to the rotation direction of the rotary shaft 11. Although it is in contact with the rotating shaft 11, the rotating shaft 1
In the rotation of 1, the tip of the thin plate 18 floats due to the dynamic pressure effect generated by the rotation of the rotating shaft 11, so that the thin plate 18
And the rotating shaft 11 are in a non-contact state. A slight gap 19 is provided between the flat thin plates 18 arranged in multiple layers. Since the gap 19 has a sufficiently large seal diameter, in other words, the diameter of the rotating shaft 11 is sufficiently large, the gap 19 can be regarded as substantially constant from the outer peripheral base end to the inner peripheral end.

In the shaft sealing mechanism configured as described above, the thin plate 18 having a width in the axial direction of the rotating shaft 11 is
It is arranged in multiple layers in the circumferential direction of the rotating shaft 11, and these thin plates 18 have soft flexibility in the circumferential direction of the rotating shaft 11,
A highly rigid sealing mechanism is formed in the axial direction. According to this sealing mechanism, the brazing on the outer peripheral side fixed to the casing 12 is performed by arranging the thin plates 18 as the sealing members in parallel to the axial direction of the rotating shaft 11.
In the axial direction. Thus, it is possible to prevent the thin plate 18 from falling off the casing 12 as in the case of a wire falling off the casing as seen in a conventional brush seal.

[0008]

However, the brush seal described above has the following problems. That is, in this brush seal, leakage from between the wires 6 and leakage from the sliding surface where the tip of the wire 6 is in contact with the outer periphery of the rotating shaft 1 poses a problem. If the allowable value determined by the arrangement of the low-pressure side plate 3 or the like is exceeded, the entire wire 6 may be deformed on the low-pressure side and fall down, and the space between the wire 6 and the rotating shaft 1 may be blown off, thereby losing the sealing function. The problem is that there is.

The stiffness of the wire 6 constituting the brush seal is determined by the followability of the rotating shaft 1 against the shaft runout and an appropriate preload with the rotating shaft 1, but by increasing the diameter of the wire 6 or the like. There is a limit in increasing rigidity. Therefore, the seal differential pressure in the direction of one axis of the rotating shaft, which is governed by the rigidity of the wire 6, is limited to about 0.5 MPa, and a large differential pressure cannot be sealed. The wire diameter of the wire 6 is usually about 50 to
It is extremely thin, 100 μm, and there is a danger that the wire 6 will break and fall off by sliding in contact with the peripheral surface of the rotating shaft 1, and there is a problem in using the gas turbine for a long time.

The amount of gas leakage from the tip of the wire 6 is
Since the wire 6 comes into contact with the peripheral surface of the rotating shaft 1 and slides, it is significantly smaller than a labyrinth seal or the like, but it is difficult to stably keep the amount of leakage from between the distal ends of the wire 6 small. There is also. Further, since the wire 6 and the peripheral surface of the rotary shaft 1 come into contact with each other and slide, the surface of the rotary shaft 1 needs to be coated with a wear-resistant material. However, a technique for forming a coating of a wear-resistant material that can withstand long-time use on the peripheral surface of the large-diameter rotary shaft 1 has not been established, and the wear of the wire 6 and the rotary shaft 1 is large. Short life and high replacement frequency.

The above-described leaf seal 10 also has the following problems. This leaf seal 10
Has a structure in which the tip of the thin plate 18 floats from the surface of the rotating shaft 11 due to the dynamic pressure effect generated by the rotation of the rotating shaft 11 to avoid contact with the rotating shaft 11 and to prevent excessive heat generation and wear. . However, when the low-pressure side plate 13 and the high-pressure side plate 14 are provided such that the gap between the low-pressure side plate 13 and the thin plate 18 is equal to the gap between the high-pressure side plate 14 and the thin plate 18, pressure is applied from the high-pressure side. It has been confirmed that a pressure load is applied to the thin plate 18 so as to deform the thin plate 18 toward the center in the radial direction of the rotating shaft 11. It was difficult to make.

Therefore, in both the brush seal and the leaf seal described above, further improvement is required to achieve both a reduction in gas leakage and an improvement in wear resistance.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has a shaft seal mechanism which reduces the amount of gas leakage from a high pressure side to a low pressure side and has excellent wear resistance, and a gas turbine having the same. The purpose is to provide.

[0014]

The present invention employs the following means in order to solve the above-mentioned problems. That is, the shaft sealing mechanism according to claim 1 of the present invention has a width in the axial direction of the rotating shaft, a leading end sliding on the peripheral surface of the rotating shaft, a gap between each other, and a base end on the outer peripheral side being a casing. A plurality of flexible thin plates fixed to the side are provided in a multiplex manner so as to seal the outer periphery of the rotating shaft in the circumferential direction of the rotating shaft, and the thin plate and the peripheral surface of the rotating shaft form an acute angle, A low-pressure side plate and a high-pressure side plate are provided on both sides of the thin plate in the rotation axis direction, respectively.A cross-sectional view of the thin plate in an imaginary plane perpendicular to the width direction of the thin plate is provided on the rotation axis of the thin plate. The facing surface is the lower surface, the back side is the upper surface, and when gas pressure is applied to the thin plate from the high-pressure side plate toward the low-pressure side plate, the upper surface at an arbitrary position along the cross section of the thin plate The gas pressure applied to the lower surface is higher than the gas pressure applied. Wherein the gas pressure adjusting means is provided that.

According to a second aspect of the present invention, the shaft sealing mechanism has a width in the axial direction of the rotating shaft, and a tip slides on a peripheral surface of the rotating shaft.
A plurality of flexible thin plates whose outer peripheral base ends are fixed to the casing side with a gap therebetween are provided in a multiplex manner so as to seal the outer periphery of the rotating shaft in a circumferential direction of the rotating shaft, and the thin plate and the A shaft sealing mechanism in which a low-pressure side plate and a high-pressure side plate are provided on both sides of the thin plate in the rotation axis direction at an acute angle with the peripheral surface of the rotating shaft, and a gas flowing from the high-pressure side plate to the low-pressure side plate. When the pressure is applied to the thin plate, the gas pressure is highest at the corner located on the tip side and on the side of the high-pressure side plate with respect to the upper and lower surfaces of the thin plate, and gradually toward the diagonal. Gas pressure adjusting means for forming a gas pressure distribution in which the gas pressure is weakened is provided.

According to the shaft sealing mechanism of the first or second aspect of the present invention, by providing the gas pressure adjusting means, the thin plate is viewed in cross section on an imaginary plane perpendicular to the width direction of the thin plate, and the thin plate is in contact with the rotation axis of the thin plate. When the gas pressure directed from the high-pressure side plate to the low-pressure side plate is applied to the thin plate, the gas pressure applied to the upper surface at an arbitrary position along the cross section of the thin plate Since the gas pressure applied to the lower surface is higher than that of the lower surface, the tip of the thin plate floats and comes into a non-contact state with the rotating shaft.

More specifically, the gas flowing from the high pressure side to the low pressure side flows between the peripheral surface of the rotating shaft and the tip of the thin plate, and along the upper and lower surfaces of each thin plate. At this time, the gas flowing along the upper and lower surfaces of each thin plate flows from between the high-pressure side plate and the peripheral surface of the rotating shaft, flows while spreading diagonally, and simultaneously applies vertically to the upper and lower surfaces of the thin plate. The pressure has a triangular distribution shape in which the pressure increases as it approaches the distal end portion and decreases as it approaches the outer peripheral base end. Although the pressure distribution shapes of the upper and lower surfaces are substantially the same as each other, since the thin plates are arranged obliquely so as to form an acute angle with respect to the peripheral surface of the rotating shaft, the relative pressure distribution on the upper and lower surfaces is relatively small. When the gas pressures of the upper and lower surfaces at an arbitrary point from the outer peripheral base end side to the distal end side of the thin plate are compared with each other, a difference occurs between the two.

That is, the gas pressure applied to the lower surface (this is referred to as Fb
) Is higher than the gas pressure applied to the upper surface (this is referred to as Fa), and acts in a direction to deform the thin plate so as to float from the rotation shaft. At this time, the gas pressure is applied only to the upper surface, and the gas pressure is applied only to the upper surface (the portion corresponding to the lower surface when the foremost portion of the thin plate is cut obliquely so as to make surface contact with the rotating shaft peripheral surface). However, this force causes the gas pressure of the gas flowing between the peripheral surface of the rotating shaft and the distal end of the thin plate to act in a direction in which the distal end of the thin plate floats from the peripheral surface of the rotating shaft (this is referred to as Fc). Since it counteracts, no force is exerted to press the thin plate tip against the rotating shaft. Therefore, the pressure load due to the gas pressure applied to the thin plate is (Fb + Fc)> Fa, so that the thin plate can be deformed so as to float above the rotating shaft peripheral surface.

In addition, when compared with a conventional brush seal wire, the size of the fixing portion for the casing can be relatively large, so that the thin plate can be firmly fixed to the casing. In addition, the tip of the thin plate has high rigidity in the axial direction of the rotating shaft and is soft in the circumferential direction of the rotating shaft, so that deformation in the differential pressure direction (axial direction) is unlikely to occur, and the seal differential pressure is allowed. In addition to increasing the value, the contact between the thin plate and the rotating shaft during the vibration of the rotating shaft is reduced.

The shaft seal mechanism according to the third aspect is the first aspect.
Or in the shaft seal mechanism according to 2, wherein the gas pressure adjusting means adjusts a gap between the thin plate and the low-pressure side plate to be larger than a gap between the thin plate and the high-pressure side plate. There is a feature.

According to the shaft seal mechanism of the third aspect, when the gas is pressurized from the high pressure side, the gas tends to flow from the high pressure side to the low pressure side through the thin plate. By making the gap between the low-pressure side plate larger than the gap between the thin plate and the high-pressure side plate and leaving a wide space,
Gas flowing from between the high-pressure side plate and the peripheral surface of the rotating shaft flows widely diagonally along the upper and lower surfaces of the thin plate, and at the same time, a low-pressure region spreads at the outer peripheral base end. Thereby, at an arbitrary position along a cross section perpendicular to the width direction of the thin plate, the gas pressure distribution applied to the upper and lower surfaces of the thin plate is formed into a triangular shape that gradually decreases from the leading end side of the thin plate toward the base end on the outer peripheral side. Can be. Therefore, for the above-mentioned reason, it is possible to generate a pressure difference between the upper and lower surfaces of the thin plate and deform the thin plate so as to float above the peripheral surface of the rotating shaft, thereby forming a non-contact state.

According to the fourth aspect of the present invention, there is provided a shaft sealing mechanism.
Or the shaft seal mechanism according to 2, wherein the gas pressure adjusting means makes the length of the low-pressure side plate in the radial direction of the rotating shaft shorter than the length of the high-pressure side plate in the radial direction of the rotating shaft. It is characterized by dimensional adjustment.

According to the shaft seal mechanism of the fourth aspect, when the gas is pressurized from the high pressure side, the gas passes through the thin plate and tends to flow from the high pressure side to the low pressure side. By making the length of the side plate in the radial direction of the rotating shaft shorter than the length of the high-pressure side plate in the radial direction of the rotating shaft and leaving a wide space on the low-pressure side, the space between the high-pressure side plate and the peripheral surface of the rotating shaft is reduced. The gas that has flowed in from between flows broadly diagonally along the upper and lower surfaces of the thin plate, and at the same time, a low pressure region spreads to the outer peripheral base. Thereby, at an arbitrary position along a cross section perpendicular to the width direction of the thin plate, the gas pressure distribution applied to the upper and lower surfaces of the thin plate is formed into a triangular shape that gradually decreases from the leading end side of the thin plate toward the base end on the outer peripheral side. Can be. Therefore, for the above-mentioned reason, it is possible to generate a pressure difference between the upper and lower surfaces of the thin plate and deform the thin plate so as to float above the peripheral surface of the rotating shaft, thereby forming a non-contact state.

According to a fifth aspect of the present invention, there is provided a shaft sealing mechanism.
3. The shaft seal mechanism according to claim 2, wherein the gas pressure adjusting means is a flexible plate disposed on the high pressure side of the thin plate and having flexibility in the rotation axis direction.

According to the shaft seal mechanism of the fifth aspect, when the gas is pressurized from the high pressure side, the gas tends to flow from the high pressure side to the low pressure side through the thin plate. A flexible plate having flexibility in the direction is provided on the high-pressure side of the thin plate (for example, the high-pressure side plate is formed into a thin plate shape having flexibility in the rotation axis direction, or a thin plate between the high-pressure side plate and the thin plate is provided. A thin plate having flexibility in the axial direction of the rotating shaft is provided in the gap, and the flexible plate is bent by the gas pressure on the high pressure side, so that the gap between the thin plate and the high pressure side plate is narrowed. It becomes smaller than the gap between the side plates. Therefore, gas flowing from between the high-pressure side plate and the peripheral surface of the rotating shaft flows widely diagonally along the upper and lower surfaces of the thin plate, and at the same time,
A low pressure region spreads to the outer peripheral base end. Thereby, at an arbitrary position along a cross section perpendicular to the width direction of the thin plate, the gas pressure distribution applied to the upper and lower surfaces of the thin plate is formed into a triangular shape that gradually decreases from the leading end side of the thin plate toward the base end on the outer peripheral side. Can be. Therefore, for the above-mentioned reason, it is possible to generate a pressure difference between the upper and lower surfaces of the thin plate and deform the thin plate so as to float above the peripheral surface of the rotating shaft, thereby forming a non-contact state.

[0026] The shaft sealing mechanism according to the sixth aspect is the first aspect.
Or the shaft seal mechanism according to 2, wherein the gas pressure adjusting means is arranged on the high pressure side of the thin plate, has flexibility in the rotation axis direction, and has two or more slits formed in the entire circumference thereof. It is a flexible plate with a slit.

According to the shaft seal mechanism of the sixth aspect, when the gas is pressurized from the high pressure side, the gas tends to flow from the high pressure side to the low pressure side through the thin plate. A flexible plate with slits having flexibility in the direction and having two or more slits formed on the entire circumference is provided on the high-pressure side of the thin plate (for example, two or more high-pressure side plates are provided on the entire circumference). Or a thin plate having a slit shape and having flexibility in the direction of the rotation axis, or having flexibility in the direction of the rotation axis between the high-pressure side plate and the thin plate and having two or more locations in the entire circumference. A thin plate with slits is formed.)
The gap between the thin plate and the high-pressure side plate is narrowed by the bending of the flexible plate due to the high-pressure gas pressure, and is smaller than the gap between the thin plate and the low-pressure side plate. Therefore, the gas flowing from between the high-pressure side plate and the peripheral surface of the rotary shaft widely flows diagonally along the upper and lower surfaces of the thin plate, and at the same time, a low-pressure region spreads to the outer peripheral base end. Thereby, at an arbitrary position along a cross section perpendicular to the width direction of the thin plate, the gas pressure distribution applied to the upper and lower surfaces of the thin plate is formed into a triangular shape that gradually decreases from the leading end side of the thin plate toward the base end on the outer peripheral side. Can be. Therefore, for the above-mentioned reason, it is possible to generate a pressure difference between the upper and lower surfaces of the thin plate and deform the thin plate so as to float above the peripheral surface of the rotating shaft, thereby forming a non-contact state.

[0028] The shaft sealing mechanism according to the seventh aspect is the first aspect.
3. The shaft seal mechanism according to claim 2, wherein the gas pressure adjusting means is a plurality of ventilation holes penetrating the low-pressure side plate in the axial direction of the rotating shaft.

According to the shaft seal mechanism of the present invention, when the gas is pressurized from the high pressure side, the gas passes through the thin plate and tends to flow from the high pressure side to the low pressure side. A plurality of ventilation holes that penetrate the low-pressure side plate in the axial direction of the low-pressure side plate are provided in the low-pressure side plate (for example, a plurality of pressure guiding holes formed in the low-pressure side plate toward the rotation axis axis direction, Alternatively, a porous material is used as the material of the low-pressure side plate, so that the gas flowing from between the high-pressure side plate and the peripheral surface of the rotating shaft spreads diagonally along the upper and lower surfaces of the thin plate. At the same time as the flow, a low pressure area spreads to the base end on the outer peripheral side. Thereby, at an arbitrary position along a cross section perpendicular to the width direction of the thin plate, the gas pressure distribution applied to the upper and lower surfaces of the thin plate is formed into a triangular shape that gradually decreases from the leading end side of the thin plate toward the base end on the outer peripheral side. Can be. Therefore, for the above-mentioned reason, it is possible to generate a pressure difference between the upper and lower surfaces of the thin plate and deform the thin plate so as to float above the peripheral surface of the rotating shaft, thereby forming a non-contact state.

In the shaft seal mechanism according to the present invention, the tip has a width in the axial direction of the rotating shaft, and the tip slides on the peripheral surface of the rotating shaft.
A plurality of flexible thin plates whose outer peripheral base ends are fixed to the casing side with a gap therebetween are provided in a multiplex manner so as to seal the outer periphery of the rotating shaft in a circumferential direction of the rotating shaft, and the thin plate and the A shaft sealing mechanism that forms an acute angle with the peripheral surface of the rotating shaft, and a gas passage space that allows the passage of gas from the high pressure side to the low pressure side is formed on the low pressure side in the axial direction of the thin plate. It is characterized by.

According to the shaft seal mechanism of the eighth aspect, when the gas is pressurized from the high pressure side, the gas tends to flow from the high pressure side to the low pressure side through the thin plate. By forming a gas passage space that allows the passage of gas from the high pressure side to the low pressure side on the low pressure side in the axial direction,
The gas flowing from between the high-pressure side plate and the peripheral surface of the rotating shaft widely flows diagonally along the upper and lower surfaces of the thin plate, and at the same time, a low-pressure region spreads to the base end on the outer peripheral side. Thereby, at an arbitrary position along a cross section perpendicular to the width direction of the thin plate, the gas pressure distribution applied to the upper and lower surfaces of the thin plate is formed into a triangular shape that gradually decreases from the leading end side of the thin plate toward the base end on the outer peripheral side. Can be. Therefore, for the above-mentioned reason, it is possible to generate a pressure difference between the upper and lower surfaces of the thin plate and deform the thin plate so as to float above the peripheral surface of the rotating shaft, thereby forming a non-contact state.

According to the ninth aspect of the present invention, there is provided a shaft seal mechanism according to the third aspect.
Or in the shaft seal mechanism according to any one of 5 or 6, when the thin plate approaches the low-pressure side plate between the low-pressure side plate and the thin plate,
A gap size adjusting means for supporting the thin plate and maintaining a gap size between the low-pressure side plate and the thin plate is provided.

According to a tenth aspect of the present invention, in the shaft seal mechanism of the ninth aspect, the gap dimension adjusting means is provided on the side of the low-pressure side plate so as to protrude toward the thin plate side. A first step-shaped portion, wherein the first step-shaped portion forms an annular shape around the rotation axis along the low-pressure side plate.

The shaft seal mechanism according to an eleventh aspect of the present invention is the shaft seal mechanism according to the tenth aspect, wherein the first step-shaped portion is provided with a ventilation hole that communicates the annular inner and outer peripheral spaces. It is characterized by being formed.

According to a twelfth aspect of the present invention, in the shaft seal mechanism of the ninth aspect, the gap dimension adjusting means is provided on the side of the low-pressure side plate so as to protrude toward the thin plate side. A plurality of second step-shaped portions, wherein the second step-shaped portions are intermittently arranged so as to form an annular shape around the rotation axis along the low-pressure side plate while being spaced apart from each other; It is characterized by comprising an annular split plate.

A shaft seal mechanism according to a thirteenth aspect is the shaft seal mechanism according to any one of the tenth to twelfth aspects,
It is characterized in that the first or second step-shaped portion is provided with a plurality of steps concentrically with the rotation axis as an axis.

According to a fourteenth aspect of the present invention, in the shaft seal mechanism of the ninth aspect, the clearance dimension adjusting means is provided on the side of the low-pressure side plate so as to project toward the thin plate side. A third step-shaped portion, wherein the third step-shaped portion is spirally arranged from the inner peripheral side to the outer peripheral side of the low-pressure side plate when the low-pressure side plate is viewed from the thin plate side. It is characterized by comprising a plurality of spiral plates provided with an interval therebetween.

According to a fifteenth aspect of the present invention, in the shaft seal mechanism according to the tenth aspect, the first stepped portion is formed up to a position of the casing along a radial direction of the low-pressure side plate. It is characterized by being.

The shaft sealing mechanism according to a sixteenth aspect is the shaft sealing mechanism according to the fifteenth aspect, wherein:
A pressure guiding hole is formed through the high-pressure side plate in the axial direction of the rotating shaft.

In the shaft seal mechanism according to a seventeenth aspect, in the shaft seal mechanism according to the ninth aspect, the gap dimension adjusting means is provided on the thin plate side so as to protrude toward the low-pressure side plate. 4 is a step-shaped portion.

According to the shaft seal mechanism according to any one of the ninth to seventeenth aspects, by providing the clearance dimension adjusting means, even if the position of the thin plate approaches the side of the low-pressure side plate, the position of the thin plate can be reduced. Since the thin plate is supported by the gap size adjusting means, the approach is prevented,
The gap between the thin plate and the low-pressure side plate must be maintained at a predetermined gap even if the thin plate and the low-pressure side plate are deformed due to an assembly error when assembling the shaft seal mechanism or fluid pressure from the high pressure side to the low pressure side during operation. Can be. Therefore, the gap between the thin plate and the low-pressure side plate can be reliably kept larger than the gap between the thin plate and the high-pressure side plate. This allows
Since the function of any one of claims 3, 5, and 6 can be reliably obtained, a pressure difference is generated between the upper and lower surfaces of the thin plate, and the thin plate is deformed so as to float from the peripheral surface of the rotating shaft. Even when the dynamic pressure effect is small, the non-contact state can be reliably formed.

Further, according to the shaft seal mechanism of the eleventh aspect, since the ventilation hole is formed in the first step-shaped portion which is the clearance dimension adjusting means, the clearance space between the thin plate and the low pressure side plate. , The resistance to the gas flow between the two spaces on the inner peripheral side in the radial direction of the rotating shaft and the outer peripheral side in the radial direction of the rotating shaft with respect to the first step-shaped portion is reduced. Thus, while the support of the thin plate by the first step-shaped portion is ensured, the pressure distribution in the radial direction of the rotating shaft in the clearance space can be formed as if the first step-shaped portion does not exist. it can. Therefore, when the gas pressure from the high-pressure side plate toward the low-pressure side plate is applied to the thin plate, the upper and lower surfaces of the thin plate are at the corners located on the distal end side facing the rotation axis and on the high-pressure side plate side. Since the gas pressure distribution is the highest, and the gas pressure distribution range in which the gas pressure gradually decreases diagonally can be formed,
The pressure difference between the upper and lower surfaces of the thin plate is reliably generated, and the gas pressure for floating the thin plate, that is, the thin plate is lifted from the peripheral surface of the rotating shaft, can be accurately adjusted.

According to the shaft sealing mechanism of the twelfth aspect, the second step-shaped portion, which is the gap dimension adjusting means, is
By forming a plurality of annular divided plates annularly spaced apart from each other, the inner circumference in the rotation axis radial direction of the gap space between the thin plate and the low-pressure side plate, bordering on the second step-shaped portion The resistance to the gas flow between the space on the side and the outer periphery in the radial direction of the rotating shaft is reduced. Thereby, while the support of the thin plate by the second step-shaped portion is ensured, the pressure distribution in the radial direction of the rotating shaft in the clearance space can be formed as if the second step-shaped portion does not exist. it can. Therefore, when the gas pressure from the high-pressure side plate toward the low-pressure side plate is applied to the thin plate, the upper and lower surfaces of the thin plate are at the corners located on the distal end side facing the rotation axis and on the high-pressure side plate side. Since the gas pressure is highest and the range of the gas pressure distribution where the gas pressure gradually decreases in the diagonal direction can be formed wider, the pressure difference between the upper and lower surfaces of the thin plate is surely generated, The gas pressure for floating the thin plate by floating the thin plate from the peripheral surface of the rotating shaft can be accurately adjusted. Also, in the shaft seal mechanism according to the thirteenth aspect, the same operation as the shaft seal mechanism according to the twelfth aspect can be obtained.

According to the shaft sealing mechanism of the fourteenth aspect, the third step-shaped portion, which is the gap dimension adjusting means, is provided.
By making a plurality of spiral plates arranged in a spiral shape at intervals, the gap between the thin plate and the low-pressure side plate, between the radially inner circumferential side of the rotating shaft and the radially outer circumferential side of the rotating shaft. The resistance to gas flow between the two spaces is reduced. This makes it possible to form the pressure distribution in the radial direction of the rotating shaft in the gap space as if the third step-shaped portion does not exist, while securing the support of the thin plate by the third step-shaped portion. it can. Therefore, when the gas pressure from the high-pressure side plate toward the low-pressure side plate is applied to the thin plate, the upper and lower surfaces of the thin plate are at the corners located on the distal end side facing the rotation axis and on the high-pressure side plate side. Since the gas pressure is highest and the range of the gas pressure distribution where the gas pressure gradually decreases in the diagonal direction can be formed wider, the pressure difference between the upper and lower surfaces of the thin plate is surely generated, The gas pressure for floating the thin plate by floating the thin plate from the peripheral surface of the rotating shaft can be accurately adjusted.

According to the shaft seal mechanism of the seventeenth aspect, the fourth step-shaped portion, which is the gap dimension adjusting means, is
Since the projection is provided on the thin plate side, the inner peripheral side in the rotation axis radial direction and the outer periphery in the rotation axis radial direction of the gap space between the thin plate and the low-pressure side plate, bordering on the fourth step-shaped portion. Since the gas flow between the two spaces on the side and the side can flow through the gap between the thin plates, the resistance to the gas flow is reduced. This makes it possible to form the pressure distribution in the radial direction of the rotating shaft in the clearance space as if the fourth step-shaped portion does not exist, while securing the support of the thin plate by the fourth step-shaped portion. it can. Therefore, when the gas pressure from the high-pressure side plate toward the low-pressure side plate is applied to the thin plate, the upper and lower surfaces of the thin plate are at the corners located on the distal end side facing the rotation axis and on the high-pressure side plate side. Since the gas pressure is highest and the range of the gas pressure distribution where the gas pressure gradually decreases in the diagonal direction can be formed wider, the pressure difference between the upper and lower surfaces of the thin plate is surely generated, The gas pressure for floating the thin plate by floating the thin plate from the peripheral surface of the rotating shaft can be accurately adjusted.

In the gas turbine according to the present invention, the gas having a high temperature and a high pressure is guided to a casing, and is blown onto a moving blade of a rotating shaft rotatably supported inside the casing, thereby mechanically transferring the heat energy of the gas to the casing. A gas turbine that generates power by converting it into rotational energy,
17. A shaft seal mechanism according to any one of (17) to (17). According to the gas turbine according to the eighteenth aspect, it is possible to obtain the same operation as the shaft seal mechanism according to the first aspect.

[0047]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a shaft seal mechanism and a gas turbine provided with the same according to the present invention will be described below, but it should be understood that the present invention is not limited to these embodiments. Of course.

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 denotes a compressor,
Reference numeral 21 denotes a combustor, and reference numeral 22 denotes a turbine. The compressor 20 takes in a large amount of air therein and compresses it. Usually, in a gas turbine, a rotating shaft 2 described later is used.
Part of the power obtained in 3 is used as power for the compressor. The combustor 21 mixes fuel with air compressed by the compressor 20 and burns it. Turbine 22
Converts the heat energy of the combustion gas into mechanical rotation energy by introducing the combustion gas generated in the combustor 21 into the interior thereof, expanding the combustion gas, and blowing the combustion gas onto a moving blade 23 e provided on the rotation shaft 23. It generates power.

The turbine 22 has a plurality of moving blades 23e on the rotating shaft 23 side and a plurality of stationary blades 24 on the casing 24 side.
The moving blades 23e and the stationary blades 24a are alternately arranged in the axial direction of the rotating shaft 23. Bucket 2
Reference numeral 3e rotates the rotating shaft 23 by receiving the pressure of the combustion gas flowing in the axial direction of the rotating shaft 23, and rotational energy given to the rotating shaft 23 is taken out from the shaft end and used. 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.

FIG. 2 is a perspective view showing the structure of the leaf seal 25. As shown in FIG.
5 has a width in the axial direction of the rotating shaft 23, the tip of which is the rotating shaft 2;
3, a plurality of flexible thin plates 29 whose outer peripheral base ends are fixed to the casing 24 side (brazing portions 28) with a gap 30 therebetween, and The outer periphery of the rotating shaft 23 is multiplexed in the direction so as to be sealable,
The thin plate 29 and the peripheral surface 23a of the rotary shaft 23 form an acute angle, and the low-pressure side plate 26 and the high-pressure side plate 27 are provided on both sides of each thin plate 29 in the rotation axis direction.

Each thin plate 29 has a flat plate shape having a predetermined width in the axial direction of the rotating shaft 23, and has a structure arranged in multiple layers in the circumferential direction of the rotating shaft 23. The base end on the outer peripheral side is brazed (brazing portion 28) in the casing 24, and by sealing the outer periphery of the rotating shaft 23, the space around the rotating shaft 23 is divided into a high-pressure side region and a low-pressure side region. Is divided into Further, on both sides in the width direction of the thin plate 29, the high-pressure side plate 27 is mounted on the high-pressure side region, and the low-pressure side plate 26 is mounted on the low-pressure side region as a guide plate in the pressure acting direction.

Then, the leaf seal 25 has the shape shown in FIG.
As shown in (a), when a gas pressure from the high pressure side region toward the low pressure side region (from the high pressure side plate 27 to the low pressure side plate 26) is applied to each thin plate 29, the upper surface 29 of each thin plate 29
a and the high-pressure side plate 2 on the distal end side with respect to the lower surface 29b.
The gas pressure adjusting means for forming the gas pressure distribution 30a in which the gas pressure is the highest at the corner r1 located on the side of No. 7 and the gas pressure gradually decreases toward the diagonal corner r2 is provided. ing.

In other words, this gas pressure adjusting means is provided in
As shown in (b), each thin plate 29 is cross-sectionally viewed on an imaginary plane perpendicular to the width direction, the surface of the thin plate 29 facing the rotation axis 23 is defined as a lower surface 29b, and the back side thereof is defined as an upper surface 29a. When a gas pressure is applied from the high-pressure side region to the low-pressure side region (from the high-pressure side plate 27 to the low-pressure side plate 26), the gas applied to the upper surface 29a at an arbitrary position along the cross section of each thin plate 29 Lower surface 29b than pressure
It is possible to adjust the gas pressure so that the gas pressure applied to is higher (for this mechanism,
I will elaborate later. ).

In the present embodiment, the gap size adjustment is performed such that the low pressure side gap 31 between each thin plate 29 and the low pressure side plate 26 is larger than the high pressure side gap 32 between each thin plate 29 and the high pressure side plate 27. Is the gas pressure adjusting means. By adjusting the gap size in this way and leaving a relatively large space on the low pressure side plate side, when pressurized from the high pressure side, it passes through each thin plate 29 from the high pressure side region to the low pressure side region. The flowing gas g flows widely diagonally along the upper surface 29a and the lower surface 29b of each thin plate 29, and at the same time, a low pressure region spreads at the base end of the outer peripheral portion. Thereby, as described above, the gas pressure distribution applied to each of the upper surface 29a and the lower surface 29b of the thin plate 29 at an arbitrary position along the cross section perpendicular to the width direction of the thin plate 29 is changed from the distal end side to the outer peripheral side of the thin plate 29. It can be a triangular shape that gradually decreases toward the base end.

More specifically, the gas g flowing from the high pressure side region toward the low pressure side region is
3, and flows along the upper surface 29a and the lower surface 29b of each thin plate 29.
At this time, the gas g flowing along the upper surface 29a and the lower surface 29b of each thin plate 29 flows from between the high-pressure side plate 27 and the peripheral surface 23a of the rotating shaft 23 as shown in FIG.
It flows radially in the direction from 1 to r2, and a low pressure region spreads at the base end on the outer peripheral side. Thereby, the upper surface 29a of each thin plate 29
Pressure distribution 30b, 30 applied perpendicularly to the lower surface 29b
As shown in FIG. 3 (b), c has a triangular distribution shape that is larger as it is closer to the distal end portion and smaller as it approaches the outer peripheral base end.

The shapes of the gas pressure distributions 30b and 30c on the upper surface 29a and the lower surface 29b are substantially the same as each other.
Because it is arranged diagonally so as to form an acute angle with respect to
The relative positions of the gas pressure distributions 30b and 30c on the upper surface 29a and the lower surface 29b are shifted by the dimension s1,
When comparing the gas pressure of the upper surface 29a and the gas pressure of the lower surface 29b at an arbitrary point P from the outer peripheral base end side to the distal end side of the thin plate 29, a difference occurs between the two.

That is, as described above, the gas pressure applied to the lower surface 29b (referred to as Fb) is higher than the gas pressure applied to the upper surface 29a (referred to as Fa).
It acts in a direction to deform the thin plate 29 so as to float from the rotation shaft 23. At this time, the gas pressure is applied only to the upper surface 29a in the vicinity of the front end of the thin plate 29, and only the gas pressure is applied to the upper surface 29a. Provided, there is no portion corresponding to the lower surface 29b.) However, this force causes the gas pressure of the gas flowing between the peripheral surface 23a and the distal end of the thin plate 29 to move the distal end of the thin plate 29 to the peripheral surface 23a. Since it acts in the direction of floating from above (this is Fc) and cancels out,
No force is generated to press the tip of the thin plate 29 against the rotating shaft 23. Therefore, since the pressure load due to the gas pressure applied to each thin plate 29 is (Fb + Fc)> Fa, it is possible to deform each thin plate 29 so as to float above the peripheral surface 23a. Therefore, a pressure difference is generated between the upper surface 29a and the lower surface 29b of each thin plate 29, and these thin plates 29 can be deformed so as to float above the peripheral surface 23a to form a non-contact state.

In the above description, a mechanism has been described in which each thin plate 29 is brought into a non-contact state with respect to the rotating shaft 23 by utilizing the differential pressure when the pressure is applied from the high pressure side. In addition, each of the thin plates 2
9 can be brought into a non-contact state with the rotating shaft 23. That is, each thin plate 29 is designed to have a predetermined rigidity determined by the plate thickness in the axial direction of the rotating shaft 23. Further, as described above, each thin plate 29 is
Is attached to the casing 24 so that an angle between the peripheral surface 23a of the rotating shaft 23 and the rotating direction of the rotating shaft 23 is acute.
When the rotating shaft 23 is stopped, the tip of each thin plate 29 is in contact with the rotating shaft 23 with a predetermined preload. However, when the rotating shaft 23 rotates, the dynamic pressure effect generated by the rotation of the rotating shaft 23 causes each thin plate 29 to rotate. Since the tip floats, the thin plate 29 and the rotating shaft 23 are in a non-contact state.

It is to be noted that each flat plate-like thin plate 29 arranged in multiple layers
A slight gap 30 (see FIG. 2) is provided between them. Since the gap 30 has a sufficiently large seal diameter, in other words, the diameter of the rotating shaft 23 is sufficiently large, the gap 30 can be regarded as substantially substantially constant from the outer peripheral base end to the inner peripheral end.

The leaf seal 2 of the present embodiment described above
5 (shaft seal mechanism) and the gas turbine having the same, the angle between each thin plate 29 and the peripheral surface 23a of the rotating shaft 23 is made acute, and the pressure adjusting means for giving buoyancy to each thin plate 29 is used as the pressure adjusting means. By providing the gap size adjustment, the pressure load difference ((Fb + Fc)> Fa) between the upper surface 29a and the lower surface 29b of the thin plate 29 even at startup or the like where the dynamic pressure effect is small.
And the tip of the thin plate 29 is connected to the peripheral surface 23a of the rotating shaft 23.
To avoid contact with the rotating shaft 23. Therefore, excessive heat generation and abrasion due to contact between each thin plate 29 and the rotating shaft 23 can be prevented. Further, since heat generation due to contact between each thin plate 29 and the rotating shaft 23 is prevented, it is also possible to avoid occurrence of vibration due to thermal balance in the rotating shaft 23.

When the vibration of the rotating shaft 23 is large, such as when passing through a resonance point, the thin plate 29 attached at an acute angle is deformed, so that the contact with the rotating shaft 23 is eased. Due to the dynamic pressure effect caused by this, the tip of each thin plate 29 can be floated from the peripheral surface 23 a of the rotating shaft 23 to avoid contact with the rotating shaft 23.

Further, by using the thin plate 29 as a sealing member, the casing 24 can be compared with a conventional wire.
Since the size of the fixed portion with respect to is increased, each thin plate 2
9 is firmly fixed to the casing 24. As a result, it is possible to prevent the thin plate 29 from dropping from the casing 24 as in the case of a wire drop in a conventional brush seal. In addition, since the tip of each thin plate 29 has high rigidity in the axial direction of the rotating shaft 23 and is soft in the circumferential direction of the rotating shaft, deformation in the direction of the differential pressure is less likely to occur as compared with the conventional brush seal. It is possible to improve the allowable value of the pressure.

Further, by making the gaps 30 between the thin plates 29 equal on the outer circumferential side and the inner circumferential side, it becomes possible to arrange the thin plates 29 more densely, and the leading end of each thin plate 29 and the rotating shaft 2
3 can be significantly reduced as compared with a non-contact labyrinth seal or the like. This makes it possible to reduce the amount of leakage to about 1/10 of the labyrinth seal, thereby improving the performance of the gas turbine by about 10%. Therefore, according to the above-described leaf seal 25 and the gas turbine including the same, it is possible to reduce the amount of gas leakage from the high-pressure side region to the low-pressure side region and to improve the wear resistance.

In the first embodiment, as the pressure adjusting means, the low-pressure side plate 26 and the high-pressure side plate 27 are arranged such that the low-pressure side gap 31 is larger than the high-pressure side gap 32, so that the high-pressure side When the pressure is applied from the side, the above-mentioned pressure load difference is generated in the thin plate 29 so that the tip end of each thin plate 29 is floated. A form can also be adopted.

Hereinafter, a second embodiment of the present invention will be described with reference to FIG. 4, but the description will be focused on its characteristic portions, and the other portions will be the same as those of the first embodiment. The description of the parts is omitted. FIG. 4 shows a thin plate upper surface 29a of each thin plate 29 when pressed from the high pressure side region.
And a leaf seal 25 provided with another pressure adjusting means for causing a pressure load difference between the thin plate lower surface 29b and floating the leading end of each thin plate 29. In the present embodiment, the length of the low-pressure side plate 26 in the radial direction of the rotating shaft 23 (the low-pressure side plate length 33) is set to the high-pressure side plate 27.
Length of the rotary shaft 23 in the radial direction (high-pressure side plate length 3
The side plate dimension adjustment shorter than 4) is used as the gas pressure adjusting means.

By adjusting the size of the side plate and leaving a relatively large space on the side of the low-pressure side plate 26 as described above, when pressurized from the high-pressure side, the gas g passes through each thin plate 29 and the gas g passes through the high-pressure side. The gas g tends to flow from the region to the low pressure side region.
Along the upper surface 29a and the lower surface 29b of each thin plate 29.
It will flow radially from 1 to r2. Thereby, as described above, the gas pressure distribution applied to each of the upper surface 29a and the lower surface 29b of the thin plate 29 at an arbitrary position along the cross section perpendicular to the width direction of the thin plate 29 is changed from the distal end side to the outer peripheral side of the thin plate 29. It can be a triangular shape that gradually decreases toward the base end. Therefore, for the same reason as in the first embodiment, a difference is generated in the relative position of the pressure distribution between the upper surface 29a and the lower surface 29b of the thin plate 29, and each thin plate 29 floats from the peripheral surface 23a of the rotating shaft 23. Thus, the non-contact state can be formed.

That is, the gas pressure distribution 30a applied perpendicularly to the upper surface 29a and the lower surface 29b of the thin plate 29 by the gas g passing through the gap 30 is similar to that of the first embodiment, and is located at the tip end of the thin plate 29 and at the high pressure. The gas pressure distribution 30a has the highest gas pressure at the corner r1 located on the side plate 27 side, and the gas pressure gradually decreases toward the diagonal corner r2.

At this time, the radial pressure distribution of an arbitrary cross section of the axial width of the thin plate 29 is the same as that of the first embodiment shown in FIG.
As shown in the gas pressure distributions 30b and 30c described in (b), a pressure load difference ((Fb + Fc)> Fa) is generated between the thin plate upper surface 29a and the thin plate lower surface 29b and the thin plate tip surface 29c. The pressure load difference acts on the thin plate 29 as a force in the direction of lifting the tip thereof. Therefore, the force in the direction of floating the tip portion acts due to the pressure load difference generated in the thin plate 29. When the present embodiment is compared with the above-described first embodiment, the size of the low-pressure side gap 31 and the high-pressure side gap 32 is controlled as in the first embodiment. It is more preferable to control the length 33 of the low-pressure side plate and the length 34 of the high-pressure side plate, because dimensional accuracy is not required and the assembly is easy, the manufacturing is easy, and the manufacturing cost can be reduced.

In this embodiment, the low pressure side plate 26
Of the rotary shaft 23 in the radial direction (the low-pressure side plate length 3
In (3), the gas pressure adjusting means is used to adjust the side plate dimension to make the length of the high-pressure side plate 27 shorter than the radial length of the rotating shaft 23 (the high-pressure side plate length 34).
On the low-pressure side of the rotating shaft 23 in the axial direction, a gas passage space that allows the passage of the gas g from the high-pressure side region to the low-pressure side region is formed (for example, a configuration in which the low-pressure side plate 26 is omitted). However, a similar effect can be obtained.

Hereinafter, a third embodiment of the present invention will be described with reference to FIGS. 5 (a) and 5 (b). The description of the same parts as those of the first embodiment is omitted. Note that, in the present embodiment, a configuration is adopted in which a flexible plate disposed on the high-pressure region side of the thin plate 29 and having flexibility in the direction of the rotation shaft 23 is used as the gas pressure adjusting means. FIG.
(A) and (b) are for generating a pressure load difference between the thin plate upper surface 29a and the thin plate lower surface 29b of each thin plate 29 when pressurized from the high pressure side region, and for floating the tip end of each thin plate 29. FIG. 5A shows a leaf seal 25 provided with another pressure adjusting means, in which the high-pressure side plate 27 is a thin plate having flexibility in the axial direction of the rotating shaft 23.
(B) is such that a high-pressure-side gap fine-adjustment thin plate 35 having flexibility in the axial direction of the rotating shaft 23 is disposed in a gap between the high-pressure side plate 27 and the thin plate 29.

The high-pressure side plate 27 having such flexibility
Alternatively, by providing the high-pressure-side gap fine-adjustment thin plate 35, when pressurized from the high-pressure side, the high-pressure-side gasket pressure causes the high-pressure side plate 27 or the high-pressure-side gap fine adjustment thin plate 35 to rotate along the axis of the rotating shaft 23. The gap between the high-pressure side plate 23 and the thin plate 29 can be kept small. At this time, the gas g flowing along the upper surface 29a and the lower surface 29b of each thin plate 29 is as shown in FIG.
, The high-pressure side plate 27 and the peripheral surface 23 of the rotating shaft 23
and flows radially in the direction from r1 to r2, and a low-pressure region spreads at the outer peripheral base end. This allows
At any position along the cross section perpendicular to the width direction of the thin plate 29, the gas pressure applied to the upper and lower surfaces of the thin plate 29 can be formed into a triangular shape that gradually decreases from the leading end of the thin plate toward the base end on the outer peripheral side. . Therefore, for the same reason as in the first embodiment, a difference is generated in the relative position of the pressure distribution between the upper surface 29a and the lower surface 29b of the thin plate 29, and each thin plate 29 floats from the peripheral surface 23a of the rotating shaft 23. Thus, the non-contact state can be formed.

That is, the gas pressure distribution 30a applied perpendicularly to the upper surface 29a and the lower surface 29b of the thin plate 29 by the gas g passing through the gap 30 is similar to that of the first embodiment, and is located at the tip end of the thin plate 29 and at the high pressure. A gas pressure distribution shape is obtained in which the gas pressure is highest at the corner r1 located on the side plate 27 side and the gas pressure gradually decreases toward the diagonal corner r2.
At this time, the radial pressure distribution of the cross section at an arbitrary position in the axial width of the thin plate 29 becomes like the gas pressure distributions 30b and 30c described with reference to FIG. Since a pressure load difference ((Fb + Fc)> Fa) is generated between the thin plate 29a and the thin plate lower surface 29b and the thin plate front end surface 29c, the pressure load difference is generated as a force in the direction of lifting the front end of the thin plate 29 with respect to the thin plate 29. Works.

Therefore, the force in the direction of lifting the tip portion acts on the thin plate 29 due to the pressure load difference generated on the thin plate 29. When this embodiment is compared with the first embodiment, for the same reasons as described in the second embodiment, the assemblability and manufacturing cost are low, and the gap (thin plate) There is a merit that the gap between the high pressure side plate 27 and the high pressure side gap fine adjustment thin plate 35) can be automatically formed with high precision.

Hereinafter, a fourth embodiment of the present invention will be described with reference to FIGS. 6 (a) and 6 (b). The description of the same parts as those of the first embodiment is omitted. In the present embodiment, the thin plate 29 is arranged on the high pressure side, has flexibility in the direction of the rotating shaft 23, and has a width of 2
A configuration is adopted in which a flexible plate with a slit in which two or more slits are formed is used as the gas pressure adjusting means. FIG. 6 (a) shows the high-pressure side plate in which two or more slits 41a are formed in the entire circumference and flexibility is provided in the axial direction of the rotating shaft 23.
FIG. 6B shows that two or more slits 42 a are formed in the gap between the high-pressure side plate 27 and the thin plate 29 in the axial direction of the rotary shaft 23 and have two or more slits around the entire circumference. In this case, the obtained thin plate is used as the flexible plate 42 with the slit.

The flexible plates 41 and 42 having such slits
Is provided, when pressurized from the high pressure side, the high pressure side plate 27 or the high pressure side gap fine adjustment thin plate 40 bends in the axial direction of the rotating shaft 23 due to the gas pressure on the high pressure side, and the high pressure side plate 2
The gap between 3 and thin plate 29 can be kept small. At this time, the gas g flowing along the upper surface 29a and the lower surface 29b of each thin plate 29 flows from between the high-pressure side plate 27 and the peripheral surface 23a of the rotating shaft 23 as shown in FIG. Flow radially in the direction, and a low pressure area spreads at the base end on the outer peripheral side. Thereby, at an arbitrary position along a cross section perpendicular to the width direction of the thin plate 29, the gas pressure applied to the upper and lower surfaces of the thin plate 29 is
The shape can be a triangular shape that gradually decreases from the distal end side of the thin plate toward the base end on the outer peripheral side. Therefore, for the same reason as in the first embodiment, the upper surface 29a of the thin plate 29 is formed.
By making a difference in the relative position of the pressure distribution between the lower surface 29b and the lower surface 29b, each thin plate 29 can be deformed so as to float above the peripheral surface 23a of the rotating shaft 23, and a non-contact state can be formed.

That is, the gas pressure distribution 30 a vertically applied to the upper surface 29 a and the lower surface 29 b of the thin plate 29 by the gas g passing through the gap 30 is similar to that in the first embodiment, and is located at the tip end of the thin plate 29 and at high pressure. A gas pressure distribution shape is obtained in which the gas pressure is highest at the corner r1 located on the side plate 27 side and the gas pressure gradually decreases toward the diagonal corner r2.
At this time, the radial pressure distribution of an arbitrary cross section of the thin plate 29 in the axial direction becomes the gas pressure distribution 30b, 30c described in FIG. 3B of the first embodiment, and the thin plate upper surface 29a , A pressure load difference ((Fb + Fc)> Fa) is generated between the thin plate lower surface 29b and the thin plate front end surface 29c, and this pressure load difference acts as a force in the direction of lifting the front end portion of the thin plate 29. I do.

Therefore, the force in the direction of lifting the tip portion acts on the thin plate 29 due to the pressure load difference generated. When this embodiment is compared with the first embodiment, for the same reasons as described in the second embodiment, the assemblability and manufacturing cost are low, and the gap (thin plate) There is a merit that a gap between the slit 29 and the slit-shaped flexible plates 41 and 42) can be automatically formed with high precision. Also, in the present embodiment, in addition to being superior in terms of assemblability and manufacturing cost as compared with the first embodiment, the third embodiment
The gaps (the thin plate 29, the flexible plate 41 with slits,
There is an advantage that the fine adjustment of the gap between the gap and the gap 42 is possible.

Hereinafter, a fifth embodiment of the present invention will be described with reference to FIG. 7, but the description will be focused on the features of the fifth embodiment, and the other features will be the same as those of the first embodiment. The description of the parts is omitted. In this embodiment, a configuration is adopted in which a plurality of ventilation holes penetrating through the low-pressure side plate 26 in the axial direction of the rotating shaft 23 are used as the gas pressure adjusting means. FIG. 7 is a cross-sectional view of the leaf seal 25 as viewed from a cross-section passing through the axis of the rotating shaft 23, and reference numeral 26a indicates the ventilation hole. In addition, a configuration using a porous material as the low-pressure side plate 26 can be adopted.

When the low-pressure side plate 26 having such ventilation holes 26a is employed, the upper surface 29a of the thin plate 29 is pressed by the gas passing through the gap 30 when pressurized with gas from the high-pressure side.
The pressure distribution of the gas pressure applied vertically to the lower surface 29b and the lower surface 29b has the isobar distribution shape shown in the pressure distribution 30a, as in the first embodiment. That is, in the thin plate 29, the gas pressure distribution shape is such that the gas pressure is highest at the corner r1 located on the distal end side and on the high-pressure side plate 27 side, and the gas pressure gradually decreases toward the diagonal corner r2. Become.

At this time, the radial pressure distribution of an arbitrary cross section of the thin plate 29 in the axial width is the same as that of the first embodiment shown in FIG.
As shown in the gas pressure distributions 30b and 30c described in (b), a pressure load difference ((Fb + Fc)> Fa) is generated between the thin plate upper surface 29a and the thin plate lower surface 29b and the thin plate tip surface 29c. The pressure load difference acts on the thin plate 29 as a force in the direction of lifting the tip thereof.

Therefore, the force in the direction of floating the tip portion acts due to the pressure load difference generated on the thin plate 29. Moreover, in the present embodiment, since only the hole shape of the ventilation hole 26a is formed, the production is easy, the assemblability is good, and the production cost can be reduced. Further, a complicated pressure distribution can be formed depending on the arrangement and size of the hole shape. Further, there is an advantage that the exposed portion of the thin plate is smaller than that of the second embodiment, and the deformation of the thin plate due to contact during assembly is small.

Hereinafter, the sixth embodiment of the present invention will be described with reference to FIG. The description of the parts is omitted. The present embodiment is particularly characterized in that it further includes a gap dimension adjusting means for maintaining the low pressure side gap 31 larger than the high pressure side gap 32 without fail.
FIG. 8A is a cross-sectional view of the leaf seal 25 viewed from a cross-section passing through the axis of the rotating shaft 23, and FIG.
It is sectional drawing seen from the -C line.

As shown in the drawing, between the low pressure side plate 26 and each thin plate 29, each thin plate 2
9 supports the thin plate 29 when approaching,
The low pressure side gap 3 between the low pressure side plate 26 and each thin plate 29
A step-shaped portion 50 (first step-shaped portion) is provided as the gap size adjusting means for maintaining the first gap size. As shown in FIG. 8A, the step-shaped portion 50 is formed such that each of the thin plates 29
8B is provided on the side of the low-pressure side plate 26 so as to project toward the side, and as shown in FIG.
When viewed from a cross section perpendicular to the axis, the ring-shaped component forms a continuous ring along the entire circumference around the rotation shaft 23 along the low-pressure side plate 26. The stepped portion 50 may be a separate component from the low-pressure side plate 26, or may be a component integrated with the low-pressure side plate 26.

In order to support each thin plate 29, it is necessary to bring the step-shaped portion 50 as close as possible to each thin plate 29 side.
However, it is necessary to prevent the step-shaped portion 50 from being deformed by pressing the side edge of each thin plate 29 too close, so that the thickness of the step-shaped portion 50 is set to t1 (the axis of the rotating shaft 23). Thickness in the direction) and the low pressure side gap 31
When the gap size of t is t2, t2 ≧ t1 (the thickness dimension t1 is equal to the gap dimension t2 of the low pressure side gap 31,
Or narrower). According to the step-shaped portion 50, the displacement or deformation of each thin plate 29 is restrained, so that the gap size t2 of the low pressure side gap 31 can be prevented from being smaller than t2, and the predetermined gap size can be easily maintained. Becomes possible.

The leaf seal 2 of the present embodiment described above
According to 5 (shaft seal mechanism) and the gas turbine provided with the same, the provision of the stepped portion 50 allows the position of each thin plate 29 to approach the low-pressure side plate 26,
Since the thin plates 29 are supported by the step-shaped portion 50, the approach is prevented. Therefore, there is an assembly error at the time of assembling the shaft seal mechanism and a fluid pressure from the high pressure side to the low pressure side at the time of operation. Even if each thin plate 29 is deformed, the gap between each thin plate 29 and the low-pressure side plate 26 can be maintained at the predetermined gap size t2.

Thus, each thin plate 29 and the low pressure side plate 26
Between the thin plates 29 and the high-pressure side plate 2.
7, the gap size adjustment described in the first embodiment, which is made larger than the high-pressure side gap 32, can be surely performed. Therefore, even when the dynamic pressure effect is small at the time of starting or the like, the tip of each thin plate 29 can be reliably lifted to make a non-contact state with the peripheral surface 23a of the rotating shaft 23. Therefore, excessive heat generation and abrasion due to contact between each thin plate 29 and the rotating shaft 23 can be prevented. Further, since heat generation due to contact between each thin plate 29 and the rotating shaft 23 is prevented, it is also possible to avoid occurrence of vibration due to thermal balance in the rotating shaft 23. In addition,
In addition, it goes without saying that the same effects as those described in the first embodiment can be obtained.

Next, a seventh embodiment of the present invention will be described with reference to FIG. This embodiment corresponds to a modified example of the sixth embodiment. Therefore, the description will be focused on the differences from the sixth embodiment, and the other points will be described. The description of the same parts as in the sixth embodiment will be omitted. 9A is a cross-sectional view of the leaf seal 25 as viewed from a cross-section passing through the axis of the rotating shaft 23, and FIG. 9B is a cross-sectional view of FIG. 9A as viewed from the line DD.

As shown in the figure, in this embodiment, the annular step-shaped portion 50 described in the sixth embodiment is used.
In addition, a characteristic feature is that a vent hole 51 is formed to communicate the annular inner and outer spaces. As shown in FIG. 9B, a plurality of the ventilation holes 51 are formed at equal intervals. As described above, by forming the plurality of ventilation holes 51 in the step-shaped portion 50, in the gap space between each thin plate 29 and the low-pressure side plate 26, in the radial direction of the rotation axis with the step-shaped portion 50 as a boundary. The resistance to the gas flow between both the space on the circumferential side and the space on the outer circumferential side in the radial direction of the rotating shaft is reduced. Thereby, while the support of each thin plate 29 by the step-shaped portion 50 is ensured, the pressure distribution in the radial direction of the rotating shaft in the clearance space can be formed as if the step-shaped portion 50 does not exist. become.

Thus, when gas pressure from the high pressure side plate 27 to the low pressure side plate 26 is applied to each thin plate 29,
With respect to the upper and lower surfaces of these thin plates 29, corners r1 located on the front end side facing the rotating shaft 23 and on the high pressure side plate 27 side.
The gas pressure distribution where the gas pressure is the highest and the gas pressure gradually decreases toward the diagonal corner r2 is widened (FIG. 9A).
In the range indicated by the solid line arrow R1).
For example, it is possible to prevent the gas pressure distribution in a narrow range indicated by a two-dot chain line arrow R2 in FIG. 9A. Therefore, a wide gas pressure distribution can be given to each thin plate 29, so that a pressure difference is reliably generated on the upper and lower surfaces of each thin plate 29 over a wide range, and these thin plates 29 are attached to the peripheral surface 23a of the rotating shaft 23. It is possible to accurately adjust the gas pressure for floating the thin plate, that is, to make it float more.

Next, an eighth embodiment of the present invention will be described with reference to FIG. This embodiment corresponds to a modified example of the sixth embodiment. Therefore, the description will be focused on the differences from the sixth embodiment, and the other points will be described. The description of the same parts as in the sixth embodiment will be omitted. (A) of FIG.
It is sectional drawing which looked at the leaf seal 25 from the cross section which passes along the axis of the rotating shaft 23, (b), (c) is sectional drawing which looked at (a) from EE line.

As shown in FIG. 10B, in the present embodiment, the step-shaped portions 50 which are annularly continuous over the entire periphery described in the sixth embodiment are replaced with equal intervals. In the state where G is placed, a step-shaped portion 50A (the second portion 50A) composed of a plurality of annular divided plates 50a intermittently arranged so as to form an annular shape around the rotation axis 23 along the low-pressure side plate 26.
Is characterized by being fixed to the low-pressure side plate 26 for one turn (one step). This step-shaped portion 50A
As shown in FIG. 10A, when viewed in a cross section passing through the axis of the rotating shaft 23, is provided on the side of the low-pressure side plate 26 so as to project toward each thin plate 29. In addition,
The step-shaped portion 50A (annular split plate 50a) may be a separate component from the low-pressure side plate 26, or may be a component integrated with the low-pressure side plate 26.

In the present embodiment, the gaps G serve as substitutes for the ventilation holes 51 of the seventh embodiment, so that the gaps between the thin plates 29 and the low-pressure side plate 26 are provided. The resistance to the gas flow between the space on the inner side in the radial direction of the rotating shaft and the outer side in the radial direction on the rotating shaft with the step-shaped portion 50A as a boundary is reduced. Thereby, while the support of each thin plate 29 by the step-shaped portion 50A is ensured, it is possible to form the pressure distribution in the radial direction of the rotating shaft in the gap space as if the step-shaped portion 50A does not exist. become.

Thus, when the gas pressure from the high pressure side plate 27 to the low pressure side plate 26 is applied to each thin plate 29,
With respect to the upper and lower surfaces of these thin plates 29, corners r1 located on the front end side facing the rotating shaft 23 and on the high pressure side plate 27 side.
The gas pressure distribution where the gas pressure is the highest and the gas pressure gradually decreases toward the diagonal corner r2 (FIG. 10)
(A range indicated by a solid arrow R1 in FIG. 10A), for example, so that a gas pressure distribution in a narrow range indicated by a two-dot chain line arrow R2 in FIG. Therefore, a wide gas pressure distribution can be given to each thin plate 29, so that a pressure difference is reliably generated on the upper and lower surfaces of each thin plate 29 over a wide range, and these thin plates 29
The gas pressure can be adjusted accurately for floating the thin plate, that is, floating the peripheral surface 23a of the rotating shaft 23.

As a modification of the present embodiment, for example, as shown in FIG. 10C, the step-shaped portion 50A is arranged concentrically around the rotation shaft 23 in two rounds (two steps). ,
Alternatively, a configuration (not shown) of arranging three or more rounds (three or more stages) is of course possible.

Next, a ninth embodiment of the present invention will be described with reference to FIG. This embodiment corresponds to a modified example of the sixth embodiment. Therefore, the description will be focused on the differences from the sixth embodiment, and the other points will be described. The description of the same parts as in the sixth embodiment will be omitted. (A) of FIG.
It is sectional drawing which looked at the leaf seal 25 from the cross section which passes along the axis of the rotating shaft 23, (b), (c) is sectional drawing which looked at (a) from FF line.

As shown in FIG. 11 (b), in this embodiment, each thin plate 29 is replaced with the stepped portion 50 which is annularly continuous over the entire circumference described in the sixth embodiment.
When the low pressure side plate 26 is viewed from the side, the low pressure side plate 26
A step-shaped portion 50B (third step-shaped portion) composed of a plurality of spiral plates 50b arranged in a spiral shape from the inner peripheral side toward the outer peripheral side and having an interval G therebetween is provided. The point that it is fixed to the low-pressure side plate 26 is particularly characteristic. As shown in FIG. 11A, the step-shaped portion 50B has a cross section passing through the axis of the rotating shaft 23, as shown in FIG.
The low-pressure side plate 26 projects toward each thin plate 29 side.
Side. And each spiral plate 50b
When the low-pressure side plate 26 is viewed from each thin plate 29 side (that is, when viewed from the line of sight of FIG. 11B), the low-pressure side plate 26 is inclined in the cross direction crossing each thin plate 29.
It is fixed to. The stepped portion 50B (spiral plate 50b) may be a separate component from the low-pressure side plate 26, or may be a component integrated with the low-pressure side plate 26.

As a modification of the present embodiment, for example, as shown in FIG.
When the low-pressure side plate 26 is viewed from the side of each thin plate 29, the low-pressure side plate 26 is tilted in the same direction and at a different tilt angle (the tilt angle of the rotating shaft 23 with respect to the peripheral surface 23a). Of course, a fixed configuration can also be adopted. However, it is more preferable to incline in the cross direction shown in FIG. 11B because a larger number of thin plates 29 can be supported by one spiral plate 50b.

In the present embodiment, since the gaps G serve as substitutes for the ventilation holes 51 of the seventh embodiment, the gap G between the thin plates 29 and the low-pressure side plate 26 is used. The resistance to the gas flow between the space on the inner side in the radial direction of the rotating shaft and the outer peripheral side in the radial direction on the rotating shaft with the step-shaped portion 50B as a boundary is reduced. Thus, the pressure distribution in the radial direction of the rotating shaft in the gap space can be formed as if the step-shaped portion 50B does not exist, while securing the support of each thin plate 29 by the step-shaped portion 50B. become.

Thus, when the gas pressure from the high pressure side plate 27 to the low pressure side plate 26 is applied to each thin plate 29,
With respect to the upper and lower surfaces of these thin plates 29, the gas pressure is highest at a corner r1 located on the tip side facing the rotating shaft 23 and on the side of the high pressure side plate, and gradually toward the diagonal corner r2. The gas pressure distribution in which the gas pressure is weakened can be formed in a wide range (the range indicated by the solid arrow R1 in FIG. 11A), and the gas pressure distribution in a narrow range can be prevented. Therefore, a wide gas pressure distribution can be given to each thin plate 29, so that a pressure difference is reliably generated on the upper and lower surfaces of each thin plate 29 over a wide range, and these thin plates 29
The gas pressure can be adjusted accurately for floating the thin plate, that is, floating the peripheral surface 23a of the rotating shaft 23.

Next, a tenth embodiment of the present invention will be described with reference to FIG. This embodiment corresponds to a modified example of the sixth embodiment. Therefore, the description will be focused on the differences from the sixth embodiment, and the other points will be described. The description of the same parts as in the sixth embodiment will be omitted. FIG. 12 is a cross-sectional view of the leaf seal 25 as viewed from a cross section passing through the axis of the rotating shaft 23.

As shown in FIG. 12, in the present embodiment,
Instead of the step-shaped portion 50 provided on the low pressure side thin plate 26 side described in the sixth embodiment, the low pressure side plate 26
This is particularly characterized in that a step-shaped portion 50C (fourth step-shaped portion) provided on each thin plate 29 side so as to project toward the thin plate 29 is provided. Each step-shaped portion 50C is a protruding portion formed integrally with each thin plate 29, and a gap having the same size as a gap formed between each thin plate 29 is generated between them.

In the present embodiment, each of the stepped portions 50 is replaced by the stepped portion 50 instead of the vent hole 51 of the seventh embodiment.
Since the gap between C is formed, in the gap space between each thin plate 29 and the low-pressure side plate 26, with the step-shaped portion 50C as a boundary,
The resistance to the gas flow between the two spaces on the inner peripheral side in the radial direction of the rotating shaft and the outer peripheral side in the radial direction on the rotating shaft is reduced. Thereby, each thin plate 2 by the step-shaped portion 50C is formed.
9, the pressure distribution in the radial direction of the rotating shaft in the clearance space can be formed as if the step-shaped portion 50C does not exist.

Accordingly, when the gas pressure from the high pressure side plate 27 to the low pressure side plate 26 is applied to each thin plate 29,
With respect to the upper and lower surfaces of these thin plates 29, corners r1 located on the front end side facing the rotating shaft 23 and on the high pressure side plate 27 side.
The gas pressure distribution where the gas pressure is the highest and the gas pressure gradually decreases toward the diagonal corner r2 can be formed in a wide range (the range indicated by the solid arrow R1 in FIG. 12). The gas pressure distribution in the narrow range shown by the two-dot chain line arrow R2 can be prevented. Therefore,
Since a wide gas pressure distribution can be given to each thin plate 29, a pressure difference is surely generated on the upper and lower surfaces of each thin plate 29 over a wide range, and these thin plates 29 are floated from the peripheral surface 23a of the rotating shaft 23. This makes it possible to accurately adjust the gas pressure for floating the thin plate. Further, in the present embodiment, only by changing the shape of each thin plate 29, the low-pressure side plate 26
Since there is no need to process or attach the device, there is also an effect that there is a great advantage in terms of manufacturing cost.

Next, an eleventh embodiment of the present invention will be described with reference to FIG. This embodiment corresponds to a modified example of the sixth embodiment. Therefore, the description will be focused on the differences from the sixth embodiment, and the other points will be described. The description of the same parts as in the sixth embodiment will be omitted. FIG. 13 is a cross-sectional view of the leaf seal 25 as viewed from a cross-section passing through the axis of the rotating shaft 23.

As shown in FIG. 13, in the present embodiment,
The annular step-shaped portion 5 described in the sixth embodiment.
It is particularly characteristic that 0 (first step-shaped portion) is formed continuously to the position of the casing 24 along the radial direction of the low-pressure side plate 26. That is, the step-shaped portion 50 of the present embodiment, when viewed in the cross section in FIG. 3, is continuous to the base position (base portion) of the low-pressure side plate 26, which is the connection portion between the casing 24 and the low-pressure side plate 26. It is formed wide. In addition, this step-shaped part 50 is
In the normal operation state, the surface facing each thin plate 29 is not in direct contact with each thin plate 29, and a small gap is formed between the two. This step-shaped part 5
According to 0, by restricting the displacement or deformation of each thin plate 29, it is possible to prevent the gap size t2 of the low pressure side gap 31 from becoming smaller than the gap size t2, and it is possible to easily maintain the gap size at a predetermined size. .

The leaf seal 2 of the present embodiment described above
According to 5 (shaft seal mechanism) and the gas turbine provided with the same, the provision of the stepped portion 50 allows the position of each thin plate 29 to approach the low-pressure side plate 26,
Since the thin plates 29 are supported by the step-shaped portion 50, the approach is prevented. Therefore, there is an assembly error at the time of assembling the shaft seal mechanism and a fluid pressure from the high pressure side to the low pressure side at the time of operation. Even if each thin plate 29 is deformed, the gap between each thin plate 29 and the low-pressure side plate 26 can be maintained at the predetermined gap size t2.

That is, each thin plate 29 and the high-pressure side plate 27
Since the gap between the high-pressure side and the low-pressure side plate 26 can be formed to have a predetermined gap size, even if a pressure fluctuation occurs between the high-pressure side and the low-pressure side, each gap size is unlikely to change. It is possible to expand the range of the seal differential pressure. Further, since a minute gap is formed between the step-shaped portion 50 and each thin plate 29 as described above, the gap tolerance between the high-pressure side plate 27 and the low-pressure side plate 26 and each thin plate 29 is relaxed. And the processing cost can be reduced. In addition, it goes without saying that effects similar to those described in the sixth embodiment can be obtained.

Next, a twelfth embodiment of the present invention will be described with reference to FIG. This embodiment corresponds to a modification of the eleventh embodiment, and therefore, will be described focusing on the differences from the eleventh embodiment. The description of the same parts as in the eleventh embodiment is omitted. FIG.
Is a cross-sectional view of the leaf seal 25 viewed from a cross-section passing through the axis of the rotating shaft 23.

As shown in FIG. 14, in the present embodiment,
In addition to the stepped portion 50 described in the eleventh embodiment, the high-pressure-side gap fine-adjustment thin plate 35 described in the third embodiment with reference to FIG. The point that it is arranged in the gap between the side plate 27 and the thin plate 29 is particularly characteristic. According to this configuration, when gas pressure from the high-pressure side plate 27 to the low-pressure side plate 26 is applied to each thin plate 29, the rotating shaft 2
The gas pressure distribution is formed such that the gas pressure is highest at the corner r1 located on the side of the high-pressure side plate 27 on the front end side opposite to the pressure side 3 and the gas pressure gradually decreases toward the diagonal corner r2. Can be. According to the leaf seal 25 (shaft seal mechanism) of the present embodiment described above and the gas turbine provided with the same, it is possible to obtain the same operation and effects as those of the above-described eleventh and third embodiments. Becomes possible.

Next, a thirteenth embodiment of the present invention will be described with reference to FIG. This embodiment is equivalent to a modification of the twelfth embodiment, and therefore, will be described focusing on the differences from the twelfth embodiment. The description of the same parts as in the twelfth embodiment is omitted. FIG.
Is a cross-sectional view of the leaf seal 25 viewed from a cross-section passing through the axis of the rotating shaft 23.

As shown in FIG. 15, in the present embodiment,
In the high-pressure side plate 27 of the twelfth embodiment, a pressure guiding hole 100 penetrating the high-pressure side plate 27 in the axial direction of the rotating shaft 23.
However, it is particularly characterized in that a plurality of such members are provided in the circumferential direction. According to this configuration, a part of the gas in the high-pressure side region can be added to the high-pressure-side gap fine-adjustment thin plate 35 so as to pass through the high-pressure side plate 27 through each pressure guiding hole 100. The side gap fine-adjustment thin plate 35 can be more effectively bent. Therefore, the first
The operation of the second embodiment can be obtained more reliably. According to the leaf seal 25 (shaft seal mechanism) of the present embodiment described above and the gas turbine provided with the same, the effects of the twelfth embodiment can be obtained more reliably.

The shaft seal mechanism according to the present invention and the first to thirteenth embodiments of the gas turbine provided with the same have been described above. This gas turbine uses a combustion gas to reduce the turbine shaft. In addition to a general gas turbine that obtains power by rotating, it also includes an aircraft gas turbine engine and 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. Further, with respect to the shaft seal mechanism (leaf seal 25) of each of the third and fourth embodiments and the gas turbine provided with the same, the clearance dimension adjusting means 50, 50A, 50B, 50 described above is provided.
A configuration in which C is combined can also be adopted. Also in this case, the gap dimension adjusting means 50, 50A, 50B, 50
Obviously, the same operation and effect can be obtained by adopting C.

[0113]

According to the shaft sealing mechanism according to any one of claims 1 to 17 of the present invention or the gas turbine according to claim 18, the angle between the thin plate and the peripheral surface of the rotary shaft is made acute, In addition, by providing pressure adjusting means so that buoyancy is applied to the thin plate, the thin plate attached at an acute angle is deformed when vibration of the rotating shaft is large, such as when passing through a resonance point, so that contact with the rotating shaft is reduced. In addition, under the rated conditions, the tip of the thin plate floats from the surface of the rotating shaft due to the dynamic pressure effect generated by the rotation of the rotating shaft, and also due to the difference in pressure load generated in the thin plate even at startup when the dynamic pressure effect is small. Contact with the shaft is avoided. Therefore, excessive heat generation and wear due to contact between the thin plate and the rotating shaft can be prevented. Further, since heat generation due to contact between the thin plate and the rotating shaft is prevented, it is possible to avoid occurrence of vibration due to thermal balance in the rotating shaft.

Further, by using a thin plate for the seal member, the fixed portion to the casing is enlarged as compared with the conventional wire, so that the thin plate is firmly fixed to the casing. As a result, it is possible to prevent the brush seal from falling off the casing, such as the wire falling off. In addition, the tip of the thin plate has high rigidity in the axial direction of the rotating shaft and is soft in the circumferential direction of the rotating shaft. Can be improved.

Further, by making the gap between the thin plates equal between the outer circumferential side and the inner circumferential side, the thin plates can be arranged more densely, and the gap between the leading end of the thin plate and the rotating shaft can be replaced with a non-contact type labyrinth seal. It can be dramatically reduced as compared to the like. As a result, the amount of gas leakage can be reduced, and when this is used in a gas turbine, its performance can be improved. Therefore, according to the shaft seal mechanism according to any one of claims 1 to 17 described above or the gas turbine according to claim 18, the amount of gas leakage from the high pressure side to the low pressure side is reduced and the wear resistance is reduced. Can be improved.

Further, according to any one of claims 11 to 14 or the shaft seal mechanism according to claim 17, or according to the gas turbine according to claim 18, which is provided with the shaft seal mechanism, the radial direction of the rotary shaft is limited. The resistance to the gas flow flowing between the space on the circumferential side and the space on the radially outer side in the radial direction of the rotating shaft is reduced. Thereby, the pressure distribution in the radial direction of the rotating shaft can be formed in the gap space between the thin plate and the low-pressure side plate while securing the support of the thin plate. Therefore, when the gas pressure from the high-pressure side plate toward the low-pressure side plate is applied to the thin plate, the upper and lower surfaces of the thin plate are at the corners located on the distal end side facing the rotation axis and on the high-pressure side plate side. Since the gas pressure is highest and the range of the gas pressure distribution where the gas pressure gradually decreases in the diagonal direction can be formed wider, the pressure difference between the upper and lower surfaces of the thin plate is surely generated, The gas pressure for floating the thin plate by floating the thin plate from the peripheral surface of the rotating shaft can be accurately adjusted.

[Brief description of the drawings]

FIG. 1 is a schematic configuration 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 perspective view of a leaf seal (shaft seal mechanism) of the embodiment.

3A and 3B are views showing the leaf seal according to the embodiment, wherein FIG. 3A is a cross-sectional view as viewed from a cross-section passing through the axis of the rotating shaft, and FIG. It is sectional drawing seen.

FIG. 4 is a shaft seal mechanism (leaf seal) according to the present invention.
FIG. 6 is a view showing a second embodiment of the present invention, and is a cross-sectional view as viewed from a cross-section passing through an axis of a rotating shaft.

FIG. 5 is a shaft seal mechanism (leaf seal) according to the present invention.
FIGS. 7A and 7B are diagrams showing a third embodiment of the present invention, wherein FIGS.
Is a cross-sectional view as seen from a cross-section passing through the axis of the rotating shaft.

FIG. 6 is a shaft seal mechanism (leaf seal) according to the present invention.
FIGS. 9A and 9B are views showing a fourth embodiment of the present invention, in which FIG. 9A is a perspective view thereof, and FIG.

FIG. 7 is a shaft seal mechanism (leaf seal) according to the present invention.
FIG. 14 is a view showing a fifth embodiment of the present invention, and is a cross-sectional view as seen from a cross-section passing through an axis of a rotating shaft.

FIG. 8 is a shaft seal mechanism (leaf seal) according to the present invention.
FIG. 13 is a view showing a sixth embodiment of the present invention, in which (a) is a cross-sectional view as viewed from a cross-section passing through the axis of the rotating shaft, and (b) is a cross-sectional view as viewed from (a) along line CC. It is.

FIG. 9 shows a shaft seal mechanism (leaf seal) according to the present invention.
FIG. 14 is a view showing a seventh embodiment of the present invention, in which (a) is a cross-sectional view as viewed from a cross-section passing through the axis of the rotating shaft, and (b) is a cross-sectional view as viewed from (a) along line DD. It is.

FIG. 10 is a view showing an eighth embodiment of a shaft seal mechanism (leaf seal) according to the present invention, wherein FIG. 10 (a) is a cross-sectional view as viewed from a cross section passing through the axis of the rotating shaft, and FIG. ),
(C) is a cross-sectional view of (a) taken along line EE.

11A and 11B are diagrams showing a ninth embodiment of the shaft seal mechanism (leaf seal) according to the present invention, in which FIG. ),
(C) is a sectional view of (a) as seen from line FF.

FIG. 12 is a view showing a tenth embodiment of a shaft seal mechanism (leaf seal) according to the present invention, and is a cross-sectional view as seen from a cross-section passing through an axis of a rotating shaft.

FIG. 13 is a shaft seal mechanism (leaf seal) according to the present invention.
FIG. 29 is a view showing the eleventh embodiment of the present invention, and is a cross-sectional view as viewed from a cross-section passing through the axis of the rotating shaft.

FIG. 14 is a shaft seal mechanism (leaf seal) according to the present invention.
FIG. 39 is a view showing the twelfth embodiment of the present invention, and is a cross-sectional view as viewed from a cross-section passing through the axis of the rotating shaft.

FIG. 15 is a shaft seal mechanism (leaf seal) according to the present invention.
FIG. 37 is a view showing a thirteenth embodiment of the present invention, and is a cross-sectional view as viewed from a cross-section passing through an axis of a rotation shaft.

16A and 16B are views showing an example of a conventional shaft sealing mechanism, wherein FIG. 16A is a cross-sectional view as viewed from a cross-section passing through the axis of the rotating shaft, and FIG. 16B is a cross-sectional view taken along line AA of FIG. It is sectional drawing seen.

FIG. 17 is a perspective view showing another example of the conventional shaft seal mechanism.

[Explanation of symbols]

Reference numeral 23: rotating shaft 23a: peripheral surface 23e: moving blade 24: casing 25: leaf seal (shaft sealing mechanism) 26: low-pressure side plate 26a: ventilation holes 27, 35 ... High-pressure side plate, high-pressure side gap fine adjustment thin plate (flexible plate) 29 ... Thin plate 29a ... Top surface 29b ... Bottom surface 30 ... Gap 30a ... Gas pressure distribution 31 ... Low pressure side gap (gap between thin plate and low pressure side plate) 32 ... High pressure side gap (gap between thin plate and high pressure side plate) 33 ... Low pressure side plate length (rotation axis of low pressure side plate) (Length in radial direction) 34 ... Length of high-pressure side plate (Length of rotation direction of high-pressure side plate in radial direction) 41, 42 ... Flexible plate with slit 41a, 42a ... Slit 50 ..Gap size adjusting means, first stepped portion 50A ... Gap size adjusting means, Second step-shaped portion 50B: gap size adjusting means, third step-shaped portion 50C: gap size adjusting means, fourth step-shaped portion 50a: annular split plate 50b: spiral plate 51 ..Ventilation hole 100 ・ ・ ・ Pressure guide hole G ・ ・ ・ Interval g ・ ・ ・ Gas r1 ・ ・ ・ Corner r2 ・ ・ ・ Corner (diagonal)

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Koichi Akagi 2-1-1, Shinhama, Arai-machi, Takasago City, Hyogo Prefecture Inside the Takasago Works, Mitsubishi Heavy Industries, Ltd. No.1 Mitsubishi Heavy Industries, Ltd. Takasago Plant F-term (reference) 3G002 HA03 HA09 3J042 AA05 BA01 CA01

Claims (18)

[Claims] 1. A plurality of flexible members each having a width in the axial direction of a rotating shaft, a leading end sliding on a peripheral surface of the rotating shaft, and a base end on an outer peripheral side fixed to a casing side with a gap therebetween. Are provided in a multiplex manner so as to seal the outer periphery of the rotating shaft in the circumferential direction of the rotating shaft, the thin plate and the circumferential surface of the rotating shaft form an acute angle, and are provided on both sides of the thin plate in the rotating shaft direction. A shaft seal mechanism provided with a low-pressure side plate and a high-pressure side plate. When a gas pressure is applied to the thin plate from the high-pressure side plate toward the low-pressure side plate, a gas applied to the lower surface more than a gas pressure applied to the upper surface at an arbitrary position along the cross section of the thin plate. Gas pressure adjusting means to increase the pressure is provided Shaft sealing mechanism, wherein the door. 2. A plurality of flexible members each having a width in the axial direction of the rotating shaft, the leading ends sliding on the peripheral surface of the rotating shaft, and the outer peripheral base fixed to the casing side with a gap therebetween. Are provided in a multiplex manner so as to seal the outer periphery of the rotating shaft in the circumferential direction of the rotating shaft, the thin plate and the circumferential surface of the rotating shaft form an acute angle, and are provided on both sides of the thin plate in the rotating shaft direction. A shaft sealing mechanism provided with a low-pressure side plate and a high-pressure side plate, wherein when gas pressure from the high-pressure side plate toward the low-pressure side plate is applied to the thin plate, the tip ends with respect to the upper and lower surfaces of the thin plate. Gas pressure adjusting means for forming a gas pressure distribution in which the gas pressure is highest at a corner located on the side of the high pressure side plate and the gas pressure gradually decreases diagonally. Characteristic shaft seal mechanism. 3. The shaft sealing mechanism according to claim 1, wherein the gas pressure adjusting means includes a gap between the thin plate and the low pressure side plate and a gap between the thin plate and the high pressure side plate. A shaft seal mechanism characterized in that the gap size is adjusted to be larger than the gap. 4. The shaft seal mechanism according to claim 1, wherein the gas pressure adjusting means adjusts a length dimension of the low-pressure side plate in the radial direction of the rotating shaft in a direction of the radial direction of the high-pressure side plate. A shaft seal mechanism wherein side plate dimensions are adjusted to be shorter than a length dimension. 5. The shaft sealing mechanism according to claim 1, wherein the gas pressure adjusting means is a flexible plate disposed on a high pressure side of the thin plate and having flexibility in the rotation axis direction. A shaft sealing mechanism. 6. The shaft sealing mechanism according to claim 1, wherein the gas pressure adjusting means is disposed on a high pressure side of the thin plate, has flexibility in the direction of the rotation axis, and has a full circumference. A shaft seal mechanism comprising a flexible plate with a slit in which two or more slits are formed. 7. The shaft seal according to claim 1, wherein the gas pressure adjusting means is a plurality of ventilation holes that penetrate the low-pressure side plate in an axial direction of the rotating shaft. mechanism. 8. A plurality of flexible members each having a width in the axial direction of the rotating shaft, the leading ends sliding on the peripheral surface of the rotating shaft, and the outer peripheral side base end fixed to the casing side with a gap therebetween. A thin plate having a multiplicity of seals in the circumferential direction of the rotating shaft so as to seal the outer periphery of the rotating shaft, wherein the thin plate and the circumferential surface of the rotating shaft form an acute angle, A shaft sealing mechanism, wherein a gas passage space is formed on the low pressure side in the axial direction to allow passage of gas from the high pressure side to the low pressure side. 9. The shaft seal mechanism according to claim 3, wherein the thin plate approaches the low-pressure side plate between the low-pressure side plate and the thin plate. A shaft seal mechanism provided with gap size adjusting means for supporting the thin plate and maintaining a gap size between the low-pressure side plate and the thin plate. 10. The shaft seal mechanism according to claim 9, wherein the gap dimension adjusting means is a first step-shaped portion provided on the side of the low-pressure side plate so as to protrude toward the thin plate side. The shaft seal mechanism, wherein the first stepped portion forms an annular shape around the rotation axis along the low-pressure side plate. 11. The shaft seal mechanism according to claim 10, wherein the first step-shaped portion is formed with a ventilation hole that communicates the annular inner and outer spaces. Shaft sealing mechanism. 12. The shaft seal mechanism according to claim 9, wherein the clearance dimension adjusting means is a second step-shaped portion provided on the side of the low-pressure side plate so as to project toward the thin plate side. The second step-shaped portion comprises a plurality of annular divided plates intermittently arranged so as to form an annular shape around the rotation axis along the low-pressure side plate while being spaced from each other. Shaft seal mechanism. 13. The shaft seal mechanism according to claim 10, wherein the first or second step-shaped portion is provided with a plurality of steps concentrically around the rotation axis. A shaft seal mechanism. 14. The shaft seal mechanism according to claim 9, wherein the clearance dimension adjusting means is a third step-shaped portion provided on the side of the low-pressure side plate so as to protrude toward the thin plate side. The third stepped portion is formed by a plurality of spiral plates arranged in a spiral from the inner peripheral side to the outer peripheral side of the low-pressure side plate when the low-pressure side plate is viewed from the thin plate side. A shaft seal mechanism characterized in that a gap is provided between the spiral plates. 15. The shaft seal according to claim 10, wherein the first stepped portion is formed up to a position of the casing along a radial direction of the low-pressure side plate. mechanism. 16. The shaft seal according to claim 15, wherein the high-pressure side plate is formed with a pressure guiding hole passing through the high-pressure side plate in an axial direction of the rotating shaft. mechanism. 17. The shaft seal mechanism according to claim 9, wherein the clearance dimension adjusting means is a fourth step-shaped portion provided on the side of the thin plate so as to project toward the low-pressure side plate. A shaft sealing mechanism. 18. A high-temperature and high-pressure gas is introduced into a casing, and is blown onto a rotor blade of a rotating shaft rotatably supported inside the casing, thereby converting heat energy of the gas into mechanical rotational energy to convert the heat energy into mechanical rotational energy. A gas turbine comprising the shaft seal mechanism according to any one of claims 1 to 17.