JP3616016B2 - Shaft seal mechanism and gas turbine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a shaft seal mechanism suitable for use in a rotating shaft of a large fluid machine such as a gas turbine, a steam turbine, a compressor, a water turbine, a refrigerator, and a pump.
The present invention also relates to a gas turbine that generates power by converting high-temperature and high-pressure gas into a turbine to expand the gas and converting the heat energy of the gas into mechanical rotational energy, and more particularly, a shaft seal mechanism applied to the rotating shaft thereof. About.
[0002]
[Prior art]
In the gas turbine, a shaft seal mechanism is provided between the stationary blade and the rotary shaft to reduce the amount of combustion gas leaking from the high pressure side to the low pressure side. As this shaft seal mechanism, a non-contact type labyrinth seal has been widely used. By the way, this labyrinth seal has a large amount of gas leakage because the gap at the tip of the fin has to be increased to some extent so that the gap at the tip of the fin does not come into contact even during shaft vibration during transient rotation or transient thermal deformation. . In place of such a labyrinth seal, there is a brush seal as a seal material developed with the aim of reducing the amount of leakage.
[0003]
16A and 16B are schematic configuration diagrams of this type of brush seal. In the figure, reference numeral 1 is a rotating shaft, reference numeral 2 is a casing, reference numeral 3 is a low-pressure side plate, reference numeral 4 is a high-pressure side plate, reference numeral 5 is a brazing portion, and reference numeral 6 is a wire. The wire 6 is composed of a filament having a suitable diameter so as to absorb vibration of the rotating shaft 1 or eccentricity due to thermal deformation, and a width of 3 to 5 mm so that there is no gap between the wires 6. It is a dense bunch of. Further, the wire 6 is attached to be inclined with respect to the rotational direction so as to form an acute angle with the outer periphery of the rotary shaft 1. The tip of the wire 6 is in contact with the outer periphery of the rotating shaft 1 with a predetermined preload, and this contact has a structure that reduces the amount of leakage in the axial direction.
[0004]
Since the wire 6 slides in contact with the rotating shaft 1 and generates heat in accordance with the atmospheric conditions or the peripheral speed and becomes in a red hot state, a heat resistant material such as Inconel or Hastelloy is used depending on the use conditions. In addition, since the sliding surface on the outer periphery of the rotating shaft 1 is worn together with the wire 6, the sliding surface of the rotating shaft 1 is coated with an abrasion resistant material. Furthermore, since the wire 6 has a small axial rigidity of the rotating shaft 1, the inner diameter of the low-pressure side plate 3 is made substantially equal to the outer periphery of the rotating shaft 1 to prevent the wire 6 from being damaged.
[0005]
In addition, for example, a leaf seal 10 as shown in FIG. 17 has been developed. As shown in the figure, the leaf seal 10 has a structure in which flat plate-like thin plates 18 having a predetermined width dimension in the axial direction of the rotary shaft 11 are arranged in multiple layers in the circumferential direction of the rotary shaft 11.
These thin plates 18 are brazed (brazed portion 15) only in the outer peripheral side base end in the casing 12, and by sealing the outer periphery of the rotating shaft 11, the space around the rotating shaft 11 is separated from the high pressure side region and the low pressure. It is divided into side areas. Further, on both sides of the thin plate 18, a high-pressure side plate 14 is attached to the high-pressure side region, and a low-pressure side plate 13 is attached to the low-pressure side region as guide plates in the pressure acting direction.
[0006]
The thin plate 18 is designed to have a predetermined rigidity determined by the plate thickness in the axial direction of the rotary shaft 11. The thin plate 18 is attached to the casing 12 so that the angle formed with the peripheral surface of the rotary shaft 11 with respect to the rotation direction of the rotary shaft 11 is an acute angle. Although the rotary shaft 11 is in contact with the preload, the tip of the thin plate 18 is lifted by the dynamic pressure effect caused by the rotation of the rotary shaft 11 when the rotary shaft 11 rotates, so the thin plate 18 and the rotary shaft 11 are not in contact with each other. It becomes a 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, it can be regarded as substantially constant from the outer peripheral side proximal end to the inner peripheral side distal end.
[0007]
In the shaft sealing mechanism configured as described above, the thin plates 18 having a width in the axial direction of the rotating shaft 11 are arranged in multiple layers in the circumferential direction of the rotating shaft 11, and these thin plates 18 are arranged around the rotating shaft 11. It has a soft flexibility in the direction and a highly rigid seal mechanism in the axial direction.
According to this sealing mechanism, the thin plates 18 that are sealing members are arranged in parallel in the axial direction of the rotary shaft 11, so that brazing on the outer peripheral side fixed to the casing 12 is strong in the axial direction of the rotary shaft 11. It will be something. As a result, the thin plate 18 can be prevented from falling off the casing 12 like the wire dropping from the casing found in the conventional brush seal.
[0008]
[Problems to be solved by the invention]
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 rotary shaft 1 are problematic, but the seal differential pressure is the wire diameter of the wire 6, If the allowable value determined by the arrangement or the like of the low-pressure side plate 3 is exceeded, the entire wire 6 may be deformed and fall down on the low-pressure side, and the gap between the wire 6 and the rotating shaft 1 may be blown out and the sealing function may be lost. It is a problem that there is.
[0009]
The rigidity of the wire 6 constituting the brush seal is determined by the followability of the rotating shaft 1 with respect to the shaft runout and the appropriate preload with the rotating shaft 1, but the rigidity is increased by increasing the wire diameter of the wire 6 or the like. There are also limitations. Therefore, the seal differential pressure in one axial direction of the rotating shaft governed by the rigidity of the wire 6 is limited to about 0.5 MPa, and a large differential pressure cannot be sealed. Further, the wire diameter of the wire 6 is usually very thin, about 50 to 100 μm, and there is a danger that the wire 6 will break and fall off when it comes into contact with the peripheral surface of the rotating shaft 1 and slides. There was a problem to use over time.
[0010]
Further, the amount of gas leakage from the tip of the wire 6 is remarkably smaller than that of a labyrinth seal or the like because the wire 6 contacts and slides on the peripheral surface of the rotating shaft 1, but the amount of leakage from the tip of the wire 6 There is also a problem that it is difficult to keep the small and stable.
Further, since the wire 6 and the peripheral surface of the rotating shaft 1 are in contact with each other and slide, the surface of the rotating 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-term use on the peripheral surface of the large-diameter rotating shaft 1 has not been established, and the wear of the wire 6 and the rotating shaft 1 is large. Life is short and replacement frequency is high.
[0011]
The above-described leaf seal 10 also has the following problems.
The leaf seal 10 has a structure in which the tip of the thin plate 18 is lifted from the surface of the rotating shaft 11 by a 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. It has become. However, when the low-pressure side plate 13 and the high-pressure side plate 14 are provided so that the gap between the low-pressure side plate 13 and the thin plate 18 and the gap between the high-pressure side plate 14 and the thin plate 18 are equal, the pressure is applied from the high-pressure side. It is confirmed that a pressure load is applied to the thin plate 18 so as to deform it toward the radial center of the rotary shaft 11, and a non-contact state is brought about at the time of start-up with a small dynamic pressure effect. It was difficult to make.
[0012]
Therefore, in both the brush seal and the leaf seal described above, further improvement is required to achieve both the reduction of gas leakage and the improvement of wear resistance.
[0013]
The present invention has been made in view of the above circumstances, and provides a shaft seal mechanism that reduces the amount of gas leakage from the high-pressure side to the low-pressure side and is excellent in wear resistance, and a gas turbine including the shaft seal mechanism. It is aimed.
[0014]
[Means for Solving the Problems]
The present invention employs the following means in order to solve the above problems.
That is, the shaft seal mechanism according to claim 1 of the present invention has a width in the axial direction of the rotating shaft, the tip slides on the peripheral surface of the rotating shaft, and a gap is formed between the outer peripheral base ends. A plurality of flexible thin plates fixed to the side are provided in multiples so that the outer periphery of the rotary shaft can be sealed in the circumferential direction of the rotary shaft, and the thin plate and the peripheral surface of the rotary shaft form an acute angle, 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 rotational axis direction, respectively, and the thin plate is viewed in a cross section in a virtual plane perpendicular to the width direction. When the gas pressure from the high-pressure side plate to the low-pressure side plate is applied to the thin plate, the upper surface at an arbitrary position along the cross section of the thin plate is applied to the thin plate. The gas pressure applied to the lower surface is higher than the gas pressure applied Gas pressure regulating means is provided thatThe gas pressure adjusting means adjusts the gap size so that the gap between the thin plate and the low-pressure side plate is larger than the gap between the thin plate and the high-pressure side plate.It is characterized by that.
[0015]
According to a second aspect of the present invention, the shaft seal mechanism has a width in the axial direction of the rotary shaft, the tip slides on the peripheral surface of the rotary shaft, and the outer peripheral base end is fixed to the casing side with a gap therebetween. A plurality of thin plates having flexibility are provided in multiple numbers so that the outer periphery of the rotary shaft can be sealed in the circumferential direction of the rotary shaft, and the thin plate and the peripheral surface of the rotary shaft form an acute angle, and the rotation of the thin plate A shaft seal mechanism in which a low-pressure side plate and a high-pressure side plate are provided on both sides in the axial direction. When gas pressure directed from the high-pressure side plate to the low-pressure side plate is applied to the thin plate, On the other hand, there is provided a gas pressure adjusting means for forming a gas pressure distribution in which the gas pressure is highest at the corner located on the tip side and on the side of the high-pressure side plate and the gas pressure gradually decreases toward the diagonal. IsThe gas pressure adjusting means adjusts the gap size so that the gap between the thin plate and the low-pressure side plate is larger than the gap between the thin plate and the high-pressure side plate.It is characterized by that.
[0016]
According to the shaft seal mechanism of the first or second aspect, by providing the gas pressure adjusting means, a cross section of the thin plate is taken along a virtual plane perpendicular to the width direction, and a surface facing the rotation axis of the thin plate is provided. When the gas pressure applied from the high pressure side plate to the low pressure side plate is applied to the thin plate, the lower surface and the back side thereof are the upper surface, than 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, the tip of the thin plate is lifted and is not in contact with the rotating shaft.
[0017]
This will be described in detail. The gas flowing from the high pressure side toward the low pressure side flows between the rotating shaft peripheral surface and the thin plate tip, 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 rotating shaft peripheral surface, flows in a diagonal direction, and simultaneously applies vertically to the upper and lower surfaces of the thin plate. The pressure has a triangular distribution shape that is larger as it is closer to the distal end portion and is smaller toward the outer peripheral side proximal end. The pressure distribution shapes on the upper and lower surfaces are substantially the same as each other. However, since the thin plates are arranged obliquely so as to form an acute angle with respect to the circumferential surface of the rotating shaft, When the gas pressures at the upper and lower surfaces at arbitrary points from the outer peripheral proximal end side to the distal end side of the thin plate are compared, a difference occurs between the two.
[0018]
That is, since the gas pressure applied to the lower surface (referred to as Fb) is higher than the gas pressure applied to the upper surface (referred to as Fa), it acts in a direction to deform the thin plate so as to float from the rotating shaft. At this time, the portion near the tip of the thin plate is reversed, and gas pressure is applied only to the upper surface (if the cutting edge of the thin plate is cut obliquely so as to make surface contact with the circumferential surface of the rotating shaft, the portion corresponding to the lower surface However, this force acts in the direction that the gas pressure flowing between the rotating shaft peripheral surface and the thin plate tip floats from the rotating shaft peripheral surface (this is referred to as Fc). Since it cancels out, the force which tries to hold down the thin-plate front-end | tip to a rotating shaft is not produced. Therefore, since the pressure load due to the gas pressure applied to the thin plate becomes (Fb + Fc)> Fa, it is possible to deform the thin plate so that it floats from the circumferential surface of the rotating shaft.
[0019]
In addition, since the size of the fixing portion relative to the casing can be made relatively large as compared with the wire of the conventional brush seal, the thin plate can be firmly fixed to the casing.
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 difficult 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 is relaxed when the rotating shaft vibrates.
[0021]
Further, in claim 1 or 2 aboveAccording to the described shaft seal mechanism, when pressurized from the high pressure side, the gas tries to flow from the high pressure side to the low pressure side through the thin plate. By making the gap larger than the gap between the thin plate and the high-pressure side plate and leaving a wide space, the gas that flows from between the high-pressure side plate and the rotating shaft circumferential surface flows along the upper and lower surfaces of the thin plate. At the same time as it flows widely toward the diagonal, a low-pressure region spreads at the outer peripheral base end. As a result, the gas pressure distribution applied to the upper and lower surfaces of the thin plate at an arbitrary position along the cross-section perpendicular to the width direction of the thin plate is a triangular shape that gradually decreases from the thin plate front end to the outer peripheral base end. Can do. Therefore, for the reason described above, a non-contact state can be formed by generating a pressure difference between the upper and lower surfaces of the thin plate and deforming the thin plate so as to float from the circumferential surface of the rotating shaft.
[0022]
Claim3The shaft seal mechanism described isA plurality of flexible thin plates having a width in the axial direction of the rotating shaft, the tip sliding on the peripheral surface of the rotating shaft, and having a gap between them and the outer peripheral base end fixed to the casing side, The outer periphery of the rotating shaft is provided in multiples so that the outer periphery of the rotating shaft can be sealed in the circumferential direction of the rotating shaft, the thin plate and the peripheral surface of the rotating shaft form an acute angle, and a low-pressure side plate and a high-pressure plate on both sides of the thin plate in the rotating shaft direction, respectively. A shaft seal mechanism provided with a side plate, wherein the thin plate is viewed in cross-section in a virtual plane perpendicular to the width direction of the thin plate, the surface facing the rotation axis of the thin plate is the lower surface, and the back side is the upper surface. On the other hand, when a gas pressure from the high-pressure side plate toward the low-pressure side plate is applied, the gas pressure applied to the lower surface is higher than the gas pressure applied to the upper surface at an arbitrary position along the cross section of the thin plate. Gas pressure adjusting means is provided,The gas pressure adjusting means is a side plate size adjustment in which the length dimension of the low pressure side plate in the radial direction of the rotation axis is shorter than the length dimension of the high pressure side plate in the radial direction of the rotation axis. .
According to a fourth aspect of the present invention, the shaft seal mechanism has a width in the axial direction of the rotary shaft, the tip slides on the peripheral surface of the rotary shaft, and the outer peripheral base end is fixed to the casing side with a gap therebetween. A plurality of thin plates having flexibility are provided in multiple numbers so that the outer periphery of the rotary shaft can be sealed in the circumferential direction of the rotary shaft, and the thin plate and the peripheral surface of the rotary shaft form an acute angle, and the rotation of the thin plate A shaft seal mechanism in which a low-pressure side plate and a high-pressure side plate are provided on both sides in the axial direction, and when gas pressure directed from the high-pressure side plate to the low-pressure side plate is applied to the thin plate, On the other hand, there is provided a gas pressure adjusting means that forms a gas pressure distribution in which the gas pressure is highest at the corner located on the tip side and on the high-pressure side plate and the gas pressure gradually decreases toward the diagonal. And the gas pressure adjusting means is configured such that the rotary shaft half of the low-pressure side plate is Characterized in that it is a plate dimensioning to the direction of the length shorter than the length of the rotary shaft radial direction of the high-pressure side plate.
[0023]
Claims above3 orAccording to the shaft seal mechanism described in No. 4, when 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. Gas flowing from between the high pressure side plate and the rotating shaft peripheral surface by making the length dimension in the direction shorter than the length dimension in the radial direction of the rotation axis of the high pressure side plate and leaving a wide space on the low pressure side 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. As a result, the gas pressure distribution applied to the upper and lower surfaces of the thin plate at an arbitrary position along the cross-section perpendicular to the width direction of the thin plate is a triangular shape that gradually decreases from the thin plate front end to the outer peripheral base end. Can do. Therefore, for the reason described above, a non-contact state can be formed by generating a pressure difference between the upper and lower surfaces of the thin plate and deforming the thin plate so as to float from the circumferential surface of the rotating shaft.
[0024]
The shaft seal mechanism according to claim 5 is:A plurality of flexible thin plates having a width in the axial direction of the rotating shaft, the tip sliding on the peripheral surface of the rotating shaft, and having a gap between them and the outer peripheral base end fixed to the casing side, The outer periphery of the rotating shaft is provided in multiples so that the outer periphery of the rotating shaft can be sealed in the circumferential direction of the rotating shaft, the thin plate and the peripheral surface of the rotating shaft form an acute angle, and a low-pressure side plate and a high-pressure plate on both sides of the thin plate in the rotating shaft direction, respectively. A shaft seal mechanism provided with a side plate, wherein the thin plate is viewed in cross-section in a virtual plane perpendicular to the width direction of the thin plate, the surface facing the rotation axis of the thin plate is the lower surface, and the back side is the upper surface. On the other hand, when a gas pressure from the high-pressure side plate toward the low-pressure side plate is applied, the gas pressure applied to the lower surface is higher than the gas pressure applied to the upper surface at an arbitrary position along the cross section of the thin plate. Gas pressure adjusting means is provided,The gas pressure adjusting means is a flexible plate that is arranged on the high-pressure side of the thin plate and has flexibility in the direction of the rotation axis.
According to a sixth aspect of the present invention, the shaft seal mechanism has a width in the axial direction of the rotary shaft, the tip slides on the peripheral surface of the rotary shaft, and the outer peripheral base end is fixed to the casing side with a gap therebetween. A plurality of thin plates having flexibility are provided in multiple numbers so that the outer periphery of the rotary shaft can be sealed in the circumferential direction of the rotary shaft, and the thin plate and the peripheral surface of the rotary shaft form an acute angle, and the rotation of the thin plate A shaft seal mechanism in which a low-pressure side plate and a high-pressure side plate are provided on both sides in the axial direction, and when gas pressure directed from the high-pressure side plate to the low-pressure side plate is applied to the thin plate, On the other hand, there is provided a gas pressure adjusting means that forms a gas pressure distribution in which the gas pressure is highest at the corner located on the tip side and on the high-pressure side plate and the gas pressure gradually decreases toward the diagonal. The gas pressure adjusting means is disposed on the high pressure side of the thin plate. Characterized in that it is a flexible plate having flexibility in the rotation axis direction.
[0025]
Claim 5 aboveOr 6According to the described shaft seal mechanism, when 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, but at this time, it has flexibility in the rotation axis direction. A flexible plate is provided on the high-pressure side of the thin plate (for example, the high-pressure side plate is formed into a thin plate having flexibility in the rotation axis direction, or the gap between the high-pressure side plate and the thin plate is arranged in the rotation axis direction. Etc.) and the flexure of the flexible plate due to the gas pressure on the high pressure side narrows the gap between the thin plate and the high pressure side plate, and the gap between the thin plate and the low pressure side plate. Smaller. Therefore, the gas flowing in between the high-pressure side plate and the peripheral surface of the rotary 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. As a result, the gas pressure distribution applied to the upper and lower surfaces of the thin plate at an arbitrary position along the cross-section perpendicular to the width direction of the thin plate is a triangular shape that gradually decreases from the thin plate front end to the outer peripheral base end. Can do. Therefore, for the reason described above, a non-contact state can be formed by generating a pressure difference between the upper and lower surfaces of the thin plate and deforming the thin plate so as to float from the circumferential surface of the rotating shaft.
[0026]
Claim7The shaft seal mechanism described isA plurality of flexible thin plates having a width in the axial direction of the rotating shaft, the tip sliding on the peripheral surface of the rotating shaft, and having a gap between them and the outer peripheral base end fixed to the casing side, The outer periphery of the rotating shaft is provided in multiples so that the outer periphery of the rotating shaft can be sealed in the circumferential direction of the rotating shaft, the thin plate and the peripheral surface of the rotating shaft form an acute angle, and a low-pressure side plate and a high-pressure plate on both sides of the thin plate in the rotating shaft direction, respectively. A shaft seal mechanism provided with a side plate, wherein the thin plate is viewed in cross-section in a virtual plane perpendicular to the width direction of the thin plate, the surface facing the rotation axis of the thin plate is the lower surface, and the back side is the upper surface. On the other hand, when a gas pressure from the high-pressure side plate toward the low-pressure side plate is applied, the gas pressure applied to the lower surface is higher than the gas pressure applied to the upper surface at an arbitrary position along the cross section of the thin plate. Gas pressure adjusting means is provided,The gas pressure adjusting means is a flexible plate with slits that is arranged on the high pressure side of the thin plate, has flexibility in the direction of the rotation axis, and has two or more slits formed on the entire circumference thereof. It is characterized by that.
The shaft seal mechanism according to claim 8 has a width in the axial direction of the rotating shaft, the tip slides on the peripheral surface of the rotating shaft, and the outer peripheral base end is fixed to the casing side with a gap therebetween. A plurality of thin plates having flexibility are provided in multiple numbers so that the outer periphery of the rotary shaft can be sealed in the circumferential direction of the rotary shaft, and the thin plate and the peripheral surface of the rotary shaft form an acute angle, and the rotation of the thin plate A shaft seal mechanism in which a low-pressure side plate and a high-pressure side plate are provided on both sides in the axial direction, and when gas pressure directed from the high-pressure side plate to the low-pressure side plate is applied to the thin plate, On the other hand, there is provided a gas pressure adjusting means that forms a gas pressure distribution in which the gas pressure is highest at the corner located on the tip side and on the high-pressure side plate and the gas pressure gradually decreases toward the diagonal. The gas pressure adjusting means is disposed on the high pressure side of the thin plate and Flexible in the rotational axis direction, and characterized in that it is a slotted flexible plate, the entire circumference at two points or more slits are formed.
[0027]
Claims above7 or 8According to the described shaft seal mechanism, when pressurized from the high pressure side, gas tends to flow from the high pressure side to the low pressure side through the thin plate. In addition, a flexible plate with slits in which two or more slits are formed on the entire circumference is provided on the high pressure side of the thin plate (for example, two or more slit shapes are formed on the entire circumference of the high voltage side plate). A thin plate having flexibility in the direction of the rotation axis, or a thin wall having flexibility in the direction of the rotation axis and having two or more slits around the entire circumference between the high-pressure side plate and the thin plate. And the flexure of the flexible plate due to the gas pressure on the high pressure side narrows the gap between the thin plate and the high pressure side plate, and becomes smaller than the gap between the thin plate and the low pressure side plate. Therefore, the gas flowing in between the high-pressure side plate and the peripheral surface of the rotary 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. As a result, the gas pressure distribution applied to the upper and lower surfaces of the thin plate at an arbitrary position along the cross-section perpendicular to the width direction of the thin plate is a triangular shape that gradually decreases from the thin plate front end to the outer peripheral base end. Can do. Therefore, for the reason described above, a non-contact state can be formed by generating a pressure difference between the upper and lower surfaces of the thin plate and deforming the thin plate so as to float from the circumferential surface of the rotating shaft.
[0028]
Claim9The shaft seal mechanism described isA plurality of flexible thin plates having a width in the axial direction of the rotating shaft, the tip sliding on the peripheral surface of the rotating shaft, and having a gap between them and the outer peripheral base end fixed to the casing side, The outer periphery of the rotating shaft is provided in multiples so that the outer periphery of the rotating shaft can be sealed in the circumferential direction of the rotating shaft, the thin plate and the peripheral surface of the rotating shaft form an acute angle, and a low-pressure side plate and a high-pressure plate on both sides of the thin plate in the rotating shaft direction, respectively. A shaft seal mechanism provided with a side plate, wherein the thin plate is viewed in cross-section in a virtual plane perpendicular to the width direction of the thin plate, the surface facing the rotation axis of the thin plate is the lower surface, and the back side is the upper surface. On the other hand, when a gas pressure from the high-pressure side plate toward the low-pressure side plate is applied, the gas pressure applied to the lower surface is higher than the gas pressure applied to the upper surface at an arbitrary position along the cross section of the thin plate. Gas pressure adjusting means is provided,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.
The shaft seal mechanism according to claim 10 has a width in the axial direction of the rotating shaft, the tip slides on the peripheral surface of the rotating shaft, and the outer peripheral side proximal end is fixed to the casing side with a gap therebetween. A plurality of thin plates having flexibility are provided in multiple numbers so that the outer periphery of the rotary shaft can be sealed in the circumferential direction of the rotary shaft, and the thin plate and the peripheral surface of the rotary shaft form an acute angle, and the rotation of the thin plate A shaft seal mechanism in which a low-pressure side plate and a high-pressure side plate are provided on both sides in the axial direction, and when gas pressure directed from the high-pressure side plate to the low-pressure side plate is applied to the thin plate, On the other hand, there is provided a gas pressure adjusting means that forms a gas pressure distribution in which the gas pressure is highest at the corner located on the tip side and on the high-pressure side plate and the gas pressure gradually decreases toward the diagonal. And the gas pressure adjusting means is arranged in the axial direction of the rotating shaft. It is a plurality of ventilation holes through the pressure side side plate.
[0029]
Claims above9 or 10According to the described shaft seal mechanism, when 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. At this time, the low pressure side plate in the axial direction of the rotating shaft A plurality of ventilation holes are provided in the low-pressure side plate (for example, a plurality of pressure guide holes formed in the direction of the rotation axis with respect to the low-pressure side plate are provided, or the material of the low-pressure side plate is provided. As a result, the gas flowing in between the high-pressure side plate and the rotary shaft peripheral surface flows widely diagonally along the top and bottom surfaces of the thin plate, and at the same time, A low pressure area spreads at the end. As a result, the gas pressure distribution applied to the upper and lower surfaces of the thin plate at an arbitrary position along the cross-section perpendicular to the width direction of the thin plate is a triangular shape that gradually decreases from the thin plate front end to the outer peripheral base end. Can do. Therefore, for the reason described above, a non-contact state can be formed by generating a pressure difference between the upper and lower surfaces of the thin plate and deforming the thin plate so as to float from the circumferential surface of the rotating shaft.
[0030]
Claim11The shaft seal mechanism described has a plurality of possible shafts having a width in the axial direction of the rotary shaft, the tip sliding on the peripheral surface of the rotary shaft, and a gap between each other and a base end on the outer peripheral side fixed to the casing side. A thin plate having flexibility is provided in multiple directions so that the outer periphery of the rotary shaft can be sealed in the circumferential direction of the rotary shaft, and the thin plate and the peripheral surface of the rotary shaft are an axis seal mechanism, and the thin plateAnd the low-pressure side plate,A gas passage space that allows passage of gas from the high pressure side to the low pressure side is formed.
[0031]
Claims above11According to the described shaft seal mechanism, when 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, but at this time, on the low pressure side in the axial direction of the thin plate, By forming a gas passage space that allows gas to pass from the high-pressure side to the low-pressure side, the gas flowing from between the high-pressure side plate and the rotating shaft peripheral surface is diagonally formed along the upper and lower surfaces of the thin plate. At the same time, a low pressure region spreads at the outer peripheral base end. As a result, the gas pressure distribution applied to the upper and lower surfaces of the thin plate at an arbitrary position along the cross-section perpendicular to the width direction of the thin plate is a triangular shape that gradually decreases from the thin plate front end to the outer peripheral base end. Can do. Therefore, for the reasons described above, a pressure difference between the upper and lower surfaces of the thin plate can be generated, and the thin plate can be deformed so as to float from the peripheral surface of the rotating shaft to form a non-contact state.
[0032]
Claim12The shaft seal mechanism described isAny one of Claims 1, 2, 5-8.In the shaft seal mechanism described in the above, when the thin plate is about to approach the low pressure side plate between the low pressure side plate and the thin plate, the thin plate is supported, and the low pressure side plate and A gap dimension adjusting means for maintaining a gap dimension between the thin plates is provided.
[0033]
Claim13The shaft seal mechanism described in the claims12In the shaft seal mechanism described above, the gap size adjusting means is a first step-shaped portion provided on the low-pressure side plate so as to protrude toward the thin plate, and the first step-shaped portion Is characterized by having an annular shape around the rotation axis along the low-pressure side plate.
[0034]
Claim14The shaft seal mechanism described in the claims13In the shaft seal mechanism described above, the first step-shaped portionIn addition,A vent hole is formed to communicate the annular inner and outer peripheral spaces.
[0035]
Claim15The shaft seal mechanism described in the claims12In the shaft seal mechanism described above, the gap dimension adjusting meansButA second step-shaped portion provided on the low-pressure side plate so as to protrude toward the thin plate, and the second step-shaped portion is spaced apart from the low-pressure side. It is characterized by comprising a plurality of annular dividing plates arranged intermittently so as to form an annular shape around the rotation axis along the side plate.
[0036]
Claim16The shaft seal mechanism described in the claimsAny one of 13-15In the shaft sealing mechanism described in (1), the first or second step-shaped portion is provided with a plurality of steps concentrically with the rotating shaft as an axis.
[0037]
Claim17The shaft seal mechanism described in the claims12In the shaft seal mechanism described above, the gap dimension adjusting means is a third step shape portion provided on the low pressure side plate side so as to protrude toward the thin plate side, and the third step shape portion However, when the low-pressure side plate is viewed from the thin plate side, the low-pressure side plate is composed of a plurality of spiral plates arranged in a spiral shape from the inner peripheral side to the outer peripheral side. , Are spaced apart from each other.
[0038]
Claim18The shaft seal mechanism described in the claims13The shaft seal mechanism described above is characterized in that the first step-shaped portion is formed to a position of the casing along a radial direction of the low-pressure side plate.
[0039]
Claim19The shaft seal mechanism described in the claims18The shaft seal mechanism described above is characterized in that a pressure guide hole is formed in the high-pressure side plate so as to penetrate the high-pressure side plate in the axial direction of the rotary shaft.
[0040]
Claim20The shaft seal mechanism described in the claims12The shaft seal mechanism described above is characterized in that the gap dimension adjusting means is a fourth step-shaped portion provided on the thin plate side so as to protrude toward the low-pressure side plate.
[0041]
Claims above12-20According to any of the shaft seal mechanisms described above, by providing the gap dimension adjusting means, even if the position of the thin plate approaches the low-pressure side plate side, the thin plate is supported by the gap dimension adjusting means. Therefore, even if there is an assembly error during assembly of the shaft seal mechanism or deformation of the thin plate due to fluid pressure from the high pressure side to the low pressure side during operation, the thin plate And the low-pressure side plate can be maintained at a predetermined gap size.
Therefore, the gap dimension between the thin plate and the low-pressure side plate can be reliably kept larger than the gap dimension between the thin plate and the high-pressure side plate. Thereby, since the effect | action of any of Claim 3, 5, 6 can be obtained reliably, the pressure difference in the upper and lower surfaces of a thin plate is produced, this thin plate is deformed so that it floats from the rotating shaft peripheral surface, A non-contact state can be reliably formed even when the dynamic pressure effect is small, such as during startup.
[0042]
Furthermore, the claim14According to the described shaft seal mechanism, the first step-shaped portion in the gap space between the thin plate and the low-pressure side plate is formed by forming the air holes in the first step-shaped portion which is the gap dimension adjusting means. The resistance to the gas flow between the space 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 at the boundary is reduced. Thereby, while ensuring the support of the thin plate by the first step shape portion, it is possible to form a pressure distribution in the radial direction of the rotation axis in the gap space as if the first step shape portion does not exist. it can.
Therefore, when gas pressure directed from the high-pressure side plate to the low-pressure side plate is applied to the thin plate, the corner portion located on the tip side facing the rotation axis and on the high-pressure side plate side with respect to the upper and lower surfaces of the thin plate. Since the gas pressure distribution range in which the gas pressure is highest and the gas pressure gradually decreases toward the diagonal can be made wider, it is possible to reliably generate a pressure difference between the upper and lower surfaces of the thin plate, It is possible to accurately adjust the gas pressure for ascending the thin plate so that the thin plate is floated from the circumferential surface of the rotating shaft.
[0043]
In addition, the above claims15According to the described shaft seal mechanism, the second step-shaped portion that is the gap dimension adjusting means is a plurality of annular divided plates that are annularly arranged at intervals from each other, so that the thin plate and the low-pressure side plate The resistance to the gas flow between the space on the inner peripheral side in the radial direction of the rotation axis and the outer peripheral side in the radial direction of the rotation axis with the second step shape portion as a boundary in the gap space between them is reduced. . Thereby, while ensuring the support of the thin plate by the second step shape portion, it is possible to form a pressure distribution in the radial direction of the rotation axis in the gap space as if the second step shape portion does not exist. it can.
Therefore, when gas pressure directed from the high-pressure side plate to the low-pressure side plate is applied to the thin plate, the corner portion located on the tip side facing the rotation axis and on the high-pressure side plate side with respect to the upper and lower surfaces of the thin plate. Since the gas pressure distribution range in which the gas pressure is highest and the gas pressure gradually decreases toward the diagonal can be made wider, it is possible to reliably generate a pressure difference between the upper and lower surfaces of the thin plate, It is possible to accurately adjust the gas pressure for ascending the thin plate so that the thin plate is floated from the circumferential surface of the rotating shaft.
Claims16Also in the shaft seal mechanism described above,15The same operation as the shaft seal mechanism described can be obtained.
[0044]
In addition, the above claims17According to the described shaft seal mechanism, the third step-shaped portion that is the gap dimension adjusting means is a plurality of spiral plates arranged in a spiral shape with a space between each other, so that the thin plate and the low-pressure side plate The resistance against the gas flow between the space between the inner peripheral side in the rotational axis radial direction and the outer peripheral side in the radial direction of the rotational axis in the gap space is reduced. Thereby, while ensuring the support of the thin plate by the third step shape portion, it is possible to form the pressure distribution in the radial direction of the rotation axis in the gap space as if the third step shape portion does not exist. it can.
Therefore, when gas pressure directed from the high-pressure side plate to the low-pressure side plate is applied to the thin plate, the corner portion located on the tip side facing the rotation axis and on the high-pressure side plate side with respect to the upper and lower surfaces of the thin plate. Since the gas pressure distribution range in which the gas pressure is highest and the gas pressure gradually decreases toward the diagonal can be made wider, it is possible to reliably generate a pressure difference between the upper and lower surfaces of the thin plate, It is possible to accurately adjust the gas pressure for ascending the thin plate so that the thin plate is floated from the circumferential surface of the rotating shaft.
[0045]
In addition, the above claims20According to the described shaft seal mechanism, the fourth step-shaped portion that is the gap dimension adjusting means is the protruding portion provided on the thin plate side, so that the gap space between the thin plate and the low-pressure side plate is Since the gas flow between both the space on the radially inner periphery side of the rotating shaft and the radially outer periphery side of the rotating shaft with the stepped shape part 4 as a boundary can flow through the gap between the thin plates, Resistance to gas flow is reduced. Thereby, while ensuring the support of the thin plate by the fourth step shape portion, it is possible to form the pressure distribution in the rotation axis radial direction in the gap space as if the fourth step shape portion does not exist. it can.
Therefore, when gas pressure directed from the high-pressure side plate to the low-pressure side plate is applied to the thin plate, the corner portion located on the tip side facing the rotation axis and on the high-pressure side plate side with respect to the upper and lower surfaces of the thin plate. Since the gas pressure distribution range in which the gas pressure is highest and the gas pressure gradually decreases toward the diagonal can be made wider, it is possible to reliably generate a pressure difference between the upper and lower surfaces of the thin plate, It is possible to accurately adjust the gas pressure for ascending the thin plate so that the thin plate is floated from the circumferential surface of the rotating shaft.
[0046]
Claim21The gas turbine according to the present invention converts high-temperature and high-pressure gas into mechanical rotation energy by guiding high-temperature and high-pressure gas to a casing and spraying it on a rotor blade of a rotating shaft that is rotatably supported inside the casing. A gas turbine for generating power is provided with the shaft seal mechanism according to any one of claims 1 to 17.
Claims above21According to the gas turbine described above,20The same action as the shaft seal mechanism described in any of the above can be obtained.
[0047]
DETAILED DESCRIPTION OF THE INVENTION
The embodiments of the shaft seal mechanism and the gas turbine equipped with the shaft seal mechanism according to the present invention will be described below, but it is needless to say that the present invention is not limited to these.
[0048]
First, the first embodiment will be described with reference to FIGS.
FIG. 1 shows a schematic configuration of the 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 and compresses it. Usually, in a gas turbine, a part of the power obtained by a rotary shaft 23 described later is used as power for the compressor. The combustor 21 mixes fuel with the air compressed by the compressor 20 and burns it. The turbine 22 introduces and expands the combustion gas generated in the combustor 21 and blows it to the rotor blades 23e provided on the rotating shaft 23 to convert the thermal energy of the combustion gas into mechanical rotational energy. Thus, power is generated.
[0049]
In addition to the plurality of moving blades 23e on the rotating shaft 23 side, the turbine 22 is provided with a plurality of stationary blades 24a on the casing 24 side. The moving blades 23e and the stationary blades 24a are arranged in the axial direction of the rotating shaft 23. Are arranged alternately. The moving blade 23e receives the pressure of the combustion gas flowing in the axial direction of the rotating shaft 23, rotates the rotating shaft 23, and the rotational energy given to the rotating shaft 23 is extracted 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.
[0050]
FIG. 2 is a perspective view showing the configuration of the leaf seal 25. As shown in the figure, the leaf seal 25 has a width in the axial direction of the rotating shaft 23, the tip slides on the peripheral surface 23a of the rotating shaft 23, and a gap 30 is formed between each other so that the base end on the outer peripheral side is A plurality of flexible thin plates 29 fixed to the casing 24 side (brazing portion 28) are provided in a multiplex manner so that the outer periphery of the rotating shaft 23 can be sealed in the circumferential direction of the rotating shaft 23, and the thin plate 29 and the rotating shaft are provided. 23 is formed with an acute angle, and a low-pressure side plate 26 and a high-pressure side plate 27 are provided on both sides of each thin plate 29 in the rotation axis direction.
[0051]
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 in which multiple layers are arranged in the circumferential direction of the rotating shaft 23. And the outer peripheral side base end is brazed (brazing part 28) in the casing 24, and the outer periphery of the rotating shaft 23 is sealed, so that the space around the rotating shaft 23 is divided into a high pressure side region and a low pressure side region. It 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.
[0052]
When the gas pressure from the high pressure side region to the low pressure side region (from the high pressure side plate 27 toward the low pressure side plate 26) is applied to each thin plate 29, as shown in FIG. Furthermore, with respect to the upper surface 29a and the lower surface 29b of each thin plate 29, the gas pressure is highest at the corner portion r1 located on the tip side and on the high pressure side plate 27 side, and gradually toward the diagonal corner portion r2. A gas pressure adjusting means for forming a gas pressure distribution 30a in which the gas pressure is weakened is provided.
[0053]
In other words, as shown in FIG. 3B, the gas pressure adjusting means is a cross-sectional view of each thin plate 29 in a virtual plane perpendicular to the width direction, and the surface of the thin plate 29 facing the rotation shaft 23 is the bottom surface. 29b, when the gas pressure 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) is applied to each thin plate 29, with the back side as the upper surface 29a. It is possible to adjust the gas pressure so that the gas pressure applied to the lower surface 29b is higher than the gas pressure applied to the upper surface 29a at an arbitrary position along the cross section (this mechanism will be described in detail later). To do.)
[0054]
In the present embodiment, the gas gap adjustment is performed so 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. The pressure adjustment means.
By adjusting the gap size in this way and leaving a relatively wide space on the low-pressure side plate side, when pressurized from the high-pressure side, it passes through each thin plate 29 and 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 outer peripheral portion base end. 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 any position along the cross section perpendicular to the width direction of the thin plate 29 is changed from the front end side to the outer peripheral side of the thin plate 29. A triangular shape that gradually decreases toward the base end can be formed.
[0055]
More specifically, the gas g flowing from the high pressure side region toward the low pressure side region is between the peripheral surface 23a of the rotating shaft 23 and the tip of the thin plate 29 and along the upper surface 29a and the lower surface 29b of each thin plate 29. Flowing. At this time, the gas g flowing along the upper surface 29a and the lower surface 29b of each thin plate 29 flows in between the high-pressure side plate 27 and the peripheral surface 23a of the rotating shaft 23, as shown in FIG. Flows radially in the direction of r2, and a low pressure region spreads at the outer peripheral base end. As a result, the gas pressure distributions 30b and 30c applied perpendicularly to the upper surface 29a and the lower surface 29b of each thin plate 29 are larger toward the distal end portion as shown in FIG. 3B and smaller toward the outer peripheral base end. A triangular distribution shape is obtained.
[0056]
The shapes of the gas pressure distributions 30b and 30c on the upper surface 29a and the lower surface 29b are substantially the same, but the thin plates 29 are arranged obliquely so as to form an acute angle with respect to the peripheral surface 23a of the rotating shaft 23. Therefore, 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, and the gas on the upper surface 29a and the lower surface 29b at an arbitrary point P from the outer peripheral proximal end side to the distal end side of the thin plate 29. When the pressures are compared, there will be a difference between the two.
[0057]
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), so that the thin plate 29 is floated from the rotating shaft 23. Acting in the direction of deformation. At this time, the portion near the tip of the thin plate 29 is reversed, and only the gas pressure is applied only to the upper surface 29a (the most distal portion of the thin plate 29 is obliquely cut so as to come into surface contact with the peripheral surface 23a and cut surface 29c. However, there is no portion corresponding to the lower surface 29b.) However, this force is caused by the gas pressure of the gas flowing between the peripheral surface 23a and the tip of the thin plate 29, and the tip of the thin plate 29 is set to the peripheral surface 23a. Therefore, the force that tries to press the tip of the thin plate 29 against the rotating shaft 23 is not generated. Therefore, since the pressure load due to the gas pressure applied to each thin plate 29 satisfies (Fb + Fc)> Fa, each thin plate 29 can be deformed so as to float from 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 from the peripheral surface 23a to form a non-contact state.
[0058]
In the above description, the mechanism for bringing each thin plate 29 into a non-contact state with respect to the rotating shaft 23 using the differential pressure when pressurized from the high pressure side has been described. Each thin plate 29 can be brought into a non-contact state with respect to the rotating shaft 23 by the rotation of the 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 rotary shaft 23. Further, as described above, each thin plate 29 is attached to the casing 24 so that the angle formed with the peripheral surface 23a of the rotation shaft 23 with respect to the rotation direction of the rotation shaft 23 is an acute angle. The tips of the thin plates 29 are in contact with the rotary shaft 23 with a predetermined preload, but the tips of the thin plates 29 float due to the dynamic pressure effect generated by the rotation of the rotary shaft 23 when the rotary shaft 23 rotates. The thin plate 29 and the rotating shaft 23 are in a non-contact state.
[0059]
Note that a slight gap 30 (see FIG. 2) is provided between the thin plate plates 29 arranged in multiple layers. 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 constant from the outer peripheral base end to the inner peripheral front end.
[0060]
According to the leaf seal 25 (shaft seal mechanism) and the gas turbine equipped with the leaf seal 25 of the present embodiment described above, the angle between each thin plate 29 and the peripheral surface 23a of the rotating shaft 23 is set to an acute angle, and each thin plate. By providing the gap size adjustment as a pressure adjusting means for giving buoyancy to 29, the pressure load difference ((Fb + Fc)> Fa) between the upper surface 29a and the lower surface 29b of the thin plate 29 even at the start-up when the dynamic pressure effect is small. And the tip of the thin plate 29 can be lifted from the peripheral surface 23a of the rotating shaft 23 to avoid contact with the rotating shaft 23. Therefore, excessive heat generation and wear 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 possible to avoid the occurrence of vibration due to thermal balance in the rotating shaft 23.
[0061]
Further, when the vibration of the rotating shaft 23 is large, such as when passing through the resonance point, the thin plate 29 attached at an acute angle is deformed and the contact with the rotating shaft 23 is relaxed, and the movement caused by the rotation of the rotating shaft 23 is also reduced. The tip of each thin plate 29 can be lifted from the peripheral surface 23a of the rotating shaft 23 by the pressure effect to avoid contact with the rotating shaft 23.
[0062]
Further, by using the thin plate 29 as the sealing member, the size of the fixing portion with respect to the casing 24 is increased as compared with the conventional wire, so that each thin plate 29 is firmly fixed to the casing 24. Thereby, it is possible to prevent the thin plate 29 from dropping off from the casing 24 like the wire dropping in the conventional brush seal.
Further, 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, it is less likely to cause deformation in the differential pressure direction than the conventional brush seal, and the difference in seal It is possible to improve the allowable pressure value.
[0063]
Further, by making the gaps 30 between the thin plates 29 equal on the outer peripheral side and the inner peripheral side, it becomes possible to arrange the thin plates 29 more densely, and the gap between the tip of each thin plate 29 and the rotary shaft 23 is reduced. Compared with a non-contact type labyrinth seal, it can be drastically reduced. As a result, the amount of leakage can be reduced to about 1/10 of the labyrinth seal, and as a result, the performance of the gas turbine can be improved by about 10%.
Therefore, according to the leaf seal 25 described above and the gas turbine including the leaf seal 25, it is possible to reduce the amount of gas leakage from the high-pressure side region to the low-pressure side region and improve wear resistance.
[0064]
By the way, in the first embodiment, as the pressure adjusting means, the low pressure side plate 26 and the high pressure side plate 27 are arranged so that the low pressure side gap 31 is larger than the high pressure side gap 32, so that the pressure adjustment means can be applied from the high pressure side. When the pressure is applied, the pressure difference is generated in the thin plate 29 so that the tip of each thin plate 29 floats. In addition to this, for example, the following embodiments are also adopted as modifications. Is possible.
[0065]
Hereinafter, the second embodiment of the present invention will be described with reference to FIG. 4. However, the description will focus on the characteristic portion, and the other parts that are the same as those of the first embodiment will be described. Description is omitted.
FIG. 4 shows another pressure adjusting means for causing a pressure load difference between the thin plate upper surface 29a and the thin plate lower surface 29b of each thin plate 29 when the pressure is applied from the high pressure side region, and for floating the tip of each thin plate 29. The leaf seal 25 provided with is shown.
In this embodiment, the radial length dimension of the rotary shaft 23 of the low-pressure side plate 26 (low-pressure side plate length 33) is the radial length dimension of the rotary shaft 23 of the high-pressure side plate 27 (high-pressure side). The side plate dimension adjustment that is shorter than the side plate length 34) is used as the gas pressure adjusting means.
[0066]
By adjusting the side plate dimensions in this way and leaving a relatively wide space on the low pressure side plate 26 side, when pressurized from the high pressure side, the gas g passes through each thin plate 29 and is low pressure from the high pressure side region. Although the gas g tends to flow to the side region, the gas g flows in a radial direction from r1 to r2 along the upper surface 29a and the lower surface 29b of each thin plate 29. 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 any position along the cross section perpendicular to the width direction of the thin plate 29 is changed from the front end side to the outer peripheral side of the thin plate 29. A triangular shape that gradually decreases toward the base end can be formed.
Therefore, for the same reason as in the first embodiment, a difference is caused 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. In this way, the non-contact state can be formed.
[0067]
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 the tip side of the thin plate 29 and the high pressure side plate 27 as in the first embodiment. The gas pressure distribution 30a is such that the gas pressure is highest at the corner r1 located on the side and gradually decreases toward the diagonal corner r2.
[0068]
At this time, the radial pressure distribution in an arbitrary cross section of the axial width of the thin plate 29 becomes the gas pressure distributions 30b and 30c described in FIG. 3B of the first embodiment, and the thin plate upper surface 29a. And a thin plate lower surface 29b and a thin plate front end surface 29c, a pressure load difference ((Fb + Fc)> Fa) is generated, and this pressure load difference acts as a force in the direction of floating the tip of the thin plate 29. To do.
Therefore, due to the pressure load difference generated in the thin plate 29, a force in the direction of floating the tip portion acts. When this embodiment is compared with the first embodiment, it is more like the present embodiment than when the dimensions of the low-pressure side gap 31 and the high-pressure side gap 32 are controlled as in the first embodiment. Furthermore, it can be said that it is more preferable to control the low-pressure side plate length 33 and the high-pressure side plate length 34 because dimensional accuracy is not required and easy, as well as easy assembly and easy manufacturing, and low manufacturing costs.
[0069]
In the present embodiment, the radial dimension (low pressure side plate length 33) of the rotary shaft 23 of the low pressure side plate 26 is set to the radial length (high pressure side) of the rotary shaft 23 of the high pressure side plate 27. Although the gas pressure adjusting means is used to adjust the side plate dimension shorter than the side plate length 34), the present invention is not limited to this, and the thin plate 29 is directed from the high pressure side region toward the low pressure side region toward the low pressure side in the axial direction of the rotating shaft 23. A similar effect can be obtained by forming a gas passage space that permits the passage of the gas g (for example, a configuration in which the low-pressure side plate 26 is omitted).
[0070]
Hereinafter, the third embodiment of the present invention will be described with reference to FIGS. 5 (a) and 5 (b). The features of the third embodiment will be mainly described, and the other first embodiments will be described. A description of the same parts as those in FIG. In the present embodiment, a configuration is adopted in which a flexible plate arranged on the high pressure region side of the thin plate 29 and having flexibility in the direction of the rotating shaft 23 is used as the gas pressure adjusting means.
FIGS. 5A and 5B show a difference in pressure load 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 the tip of each thin plate 29 is levitated. FIG. 5 (a) shows a case where the high-pressure side plate 27 is a thin plate having flexibility in the axial direction of the rotary shaft 23. FIG. In FIG. 5B, a high pressure side clearance fine adjustment thin plate 35 having flexibility in the axial direction of the rotary shaft 23 is disposed in the clearance between the high pressure side plate 27 and the thin plate 29.
[0071]
By providing such a flexible high-pressure side plate 27 or high-pressure side clearance fine adjustment thin plate 35, the high-pressure side plate 27 or the high-pressure side is caused by the gas pressure on the high-pressure side when pressurized from the high-pressure side. The gap fine adjustment thin plate 35 bends in the axial direction of the rotary shaft 23, and 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 flows in between the high-pressure side plate 27 and the peripheral surface 23a of the rotating shaft 23 as shown in FIG. Flows radially in the direction, and a low-pressure region spreads at the outer peripheral base end. As a result, the gas pressure applied to the upper and lower surfaces of the thin plate 29 at an arbitrary position along the cross section perpendicular to the width direction of the thin plate 29 has a triangular shape that gradually decreases from the front end side of the thin plate toward the base end on the outer peripheral side. be able to.
Therefore, for the same reason as in the first embodiment, a difference is caused 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. In this way, the non-contact state can be formed.
[0072]
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 the tip side of the thin plate 29 and the high pressure side plate 27 as in the first embodiment. The gas pressure distribution shape is such that the gas pressure is highest at the corner portion r1 located on the side and gradually decreases toward the diagonal corner portion r2. At this time, the radial pressure distribution of the cross section at an arbitrary position of the axial width of the thin plate 29 becomes the gas pressure distribution 30b, 30c described in FIG. 3B of the first embodiment, and the upper surface of the thin plate Since a pressure load difference ((Fb + Fc)> Fa) is generated between the thin plate lower surface 29b and the thin plate front end surface 29c, this pressure load difference is a force in the direction in which the front end portion of the thin plate 29 is levitated. Works.
[0073]
Therefore, due to the pressure load difference generated in the thin plate 29, a force in the direction of floating the tip portion acts. When this embodiment is compared with the first embodiment, for the same reason as described in the second embodiment, the assemblability and the manufacturing cost are low, and the gap (thin plate) is caused by the seal differential pressure. 29 and the high-pressure side plate 27 or the high-pressure side gap fine adjustment thin plate 35) can be automatically formed with high accuracy.
[0074]
Hereinafter, the fourth embodiment of the present invention will be described with reference to FIGS. 6 (a) and 6 (b). The features will be mainly described, and the other first embodiments will be described. A description of the same parts as those in FIG. In the present embodiment, a flexible plate with slits arranged on the high-pressure side of the thin plate 29 and having flexibility in the direction of the rotary shaft 23 and having two or more slits formed on the entire circumference thereof. A configuration as the gas pressure adjusting means is adopted.
FIG. 6A shows a slit-formed flexible plate 41 in which two or more slits 41a are formed on the entire circumference of the high-pressure side plate and are flexible in the axial direction of the rotary shaft 23. FIG. 6B shows a case in which 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 at the entire circumference. The case where the thin plate made into the said flexible plate 42 with a slit is shown.
[0075]
By providing such flexible plates 41 and 42 with slits, when pressurized from the high pressure side, the high pressure side plate 27 or the high pressure side clearance fine adjustment thin plate 40 is rotated by the rotating shaft 23 due to the gas pressure on the high pressure side. 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 flows in between the high-pressure side plate 27 and the peripheral surface 23a of the rotating shaft 23 as shown in FIG. Flows radially in the direction, and a low-pressure region spreads at the outer peripheral base end. As a result, the gas pressure applied to the upper and lower surfaces of the thin plate 29 at an arbitrary position along the cross section perpendicular to the width direction of the thin plate 29 has a triangular shape that gradually decreases from the front end side of the thin plate toward the base end on the outer peripheral side. be able to.
Therefore, for the same reason as in the first embodiment, a difference is caused 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. In this way, the non-contact state can be formed.
[0076]
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 the tip side of the thin plate 29 and the high pressure side plate 27 as in the first embodiment. The gas pressure distribution shape is such that the gas pressure is highest at the corner portion r1 located on the side and gradually decreases toward the diagonal corner portion r2. At this time, the radial pressure distribution in an arbitrary cross section of the axial width of the thin plate 29 becomes the gas pressure distributions 30b and 30c described in FIG. 3B of the first embodiment, and the thin plate upper surface 29a. And a thin plate lower surface 29b and a thin plate front end surface 29c, a pressure load difference ((Fb + Fc)> Fa) is generated, and this pressure load difference acts as a force in the direction of floating the tip of the thin plate 29. To do.
[0077]
Therefore, due to the pressure load difference generated in the thin plate 29, a force in the direction of floating the tip portion acts. When this embodiment is compared with the first embodiment, for the same reason as described in the second embodiment, the assemblability and the manufacturing cost are low, and the gap (thin plate) is caused by the seal differential pressure. 29 and the slits (flexible plates 41 and 42) can be automatically formed with high accuracy. Further, in the present embodiment, in addition to being excellent in assemblability and manufacturing cost as compared with the first embodiment, a gap is also formed by the shape of the slits 41a and 42a as compared with the third embodiment. There is an advantage that fine adjustment of (the gap between the thin plate 29 and the flexible plates 41 and 42 with slits) is possible.
[0078]
In the following, the fifth embodiment of the present invention will be described with reference to FIG. 7, but the description will focus on the characteristic parts, and the other parts that are the same as in the first embodiment will be described. Description is omitted. In the present embodiment, a configuration is adopted in which a plurality of ventilation holes penetrating 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 rotary shaft 23, and the reference numeral 26a indicates the vent hole. In addition, a configuration using a porous material as the low-pressure side plate 26 can be employed.
[0079]
When the low pressure side plate 26 having such a ventilation hole 26a is employed, the gas pressure applied perpendicularly to the upper surface 29a and the lower surface 29b of the thin plate 29 by the gas passing through the gap 30 when pressurized with gas from the high pressure side. Similar to the first embodiment, the pressure distribution has the isobar distribution shape shown in the pressure distribution 30a. That is, in the thin plate 29, the gas pressure distribution shape in which the gas pressure is highest at the corner portion r1 located on the tip side and on the high pressure side plate 27 side, and the gas pressure gradually decreases toward the diagonal corner portion r2. Become.
[0080]
At this time, the radial pressure distribution in an arbitrary cross section of the axial width of the thin plate 29 becomes the gas pressure distributions 30b and 30c described in FIG. 3B of the first embodiment, and the thin plate upper surface 29a. And a thin plate lower surface 29b and a thin plate front end surface 29c, a pressure load difference ((Fb + Fc)> Fa) is generated, and this pressure load difference acts as a force in the direction of floating the tip of the thin plate 29. To do.
[0081]
Therefore, due to the pressure load difference generated in the thin plate 29, a force in the direction of floating the tip portion acts. In addition, in the present embodiment, since only the hole shape of the ventilation hole 26a is formed, the manufacturing is easy, the assemblability is good, and the manufacturing cost can be reduced. Furthermore, a complicated pressure distribution can be formed by the arrangement and size of the hole shape. In addition, the exposed portion of the thin plate is smaller than that of the second embodiment, and there is an advantage that the deformation of the thin plate due to contact during assembly is small.
[0082]
In the following, the sixth embodiment of the present invention will be described with reference to FIG. 8, but its characteristic part will be mainly described, and other parts that are the same as those of the first embodiment will be described. Description is omitted. The present embodiment is particularly characterized in that it further includes gap size adjusting means for maintaining the low-pressure side gap 31 to be always larger than the high-pressure side gap 32.
8A is a cross-sectional view of the leaf seal 25 as viewed from a cross section passing through the axis of the rotary shaft 23, and FIG. 8B is a cross-sectional view of the leaf seal 25 as viewed from line CC.
[0083]
As shown in the figure, when each thin plate 29 is about to approach the low-pressure side plate 26 between the low-pressure side plate 26 and each thin plate 29, the thin plate 29 is supported and these low-pressure side plates 26 are supported. A step shape portion 50 (first step shape portion) is provided as the gap size adjusting means for maintaining the gap size of the low pressure side gap 31 between the side plate 26 and each thin plate 29.
As shown in FIG. 8A, the stepped portion 50 is formed on the low pressure side plate 26 side so as to protrude toward the thin plate 29 side when viewed in a cross section passing through the axis of the rotary shaft 23. As shown in FIG. 8B, when viewed from a cross section perpendicular to the axis of the rotating shaft 23, the entire circumference around the rotating shaft 23 is formed along the annular low-pressure side plate 26. It is a ring-shaped part that forms a continuous ring. The step-shaped 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.
[0084]
In order to support each thin plate 29, the stepped portion 50 needs to be as close as possible to each thin plate 29 side. However, since it is necessary to prevent the stepped portion 50 from being deformed by being too close to the side edges of the thin plates 29, the thickness dimension of the stepped portion 50 is set to t1 (the axis of the rotating shaft 23). (Thickness dimension in the direction) and t2 is the clearance dimension of the low-pressure side gap 31 (the thickness dimension t1 is equal to or smaller than the clearance dimension t2 of the low-pressure side gap 31). There is a need to. According to this step-shaped portion 50, by restraining the displacement or deformation of each thin plate 29, it is possible to prevent the low-pressure side gap 31 from becoming smaller than the gap dimension t2, and easily maintain the predetermined gap dimension. Is possible.
[0085]
According to the leaf seal 25 (shaft seal mechanism) and the gas turbine equipped with the leaf seal 25 of the present embodiment described above, the position of each thin plate 29 is on the low pressure side plate 26 side by providing the step-shaped portion 50. The thin plate 29 is supported by the step-shaped portion 50 even if it approaches, so that the approach is prevented. Therefore, from the assembly error during assembly of the shaft seal mechanism and the high pressure side during operation. Even if the thin plates 29 are deformed by the fluid pressure toward the low pressure side, the gaps between the thin plates 29 and the low pressure side plates 26 can be maintained at a predetermined gap dimension t2.
[0086]
Thereby, the low pressure side gap 31 between each thin plate 29 and the low pressure side plate 26 is made larger than the high pressure side gap 32 between each thin plate 29 and the high pressure side plate 27. It is possible to reliably perform the gap dimension adjustment described in the above. Therefore, even when the dynamic pressure effect is small, such as at the time of activation, the tip of each thin plate 29 can be reliably lifted so as not to be in contact with the peripheral surface 23a of the rotating shaft 23. Therefore, excessive heat generation and wear 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 possible to avoid the occurrence of vibration due to thermal balance in the rotating shaft 23. In addition to this, it goes without saying that the same effects as those described in the first embodiment can be obtained.
[0087]
Next, a seventh embodiment of the present invention will be described with reference to FIG. The present embodiment corresponds to a modification of the sixth embodiment, and therefore, the description will focus on the differences from the sixth embodiment. The description of the same parts as those in the sixth embodiment will be omitted.
(A) of FIG. 9 is sectional drawing which looked at the leaf seal 25 from the cross section which passes along the axis line of the rotating shaft 23, (b) is sectional drawing which looked at (a) from DD line.
[0088]
As shown in the figure, in the present embodiment, the annular stepped portion 50 described in the sixth embodiment is provided with a vent hole 51 for communicating the space on the inner peripheral side and the outer peripheral side of the ring. The points formed are characteristic. As shown in FIG. 9B, a plurality of the vent holes 51 are formed at equal intervals.
In this way, by forming the plurality of vent holes 51 in the stepped portion 50, in the radial direction of the rotation axis with the stepped portion 50 as a boundary in the gap space between each thin plate 29 and the low-pressure side plate 26. Resistance to gas flow between both the space on the peripheral side and the outer peripheral side in the radial direction of the rotation axis is reduced. Thereby, while ensuring the support of each thin plate 29 by the step-shaped portion 50, it is possible to form a pressure distribution in the rotation axis radial direction in the gap space as if the step-shaped portion 50 does not exist. become.
[0089]
As a result, when a gas pressure from the high-pressure side plate 27 toward the low-pressure side plate 26 is applied to each thin plate 29, the top and bottom surfaces of the thin plates 29 facing the rotating shaft 23 and the high-pressure side plate 27. The gas pressure distribution at which the gas pressure is highest at the corner r1 located on the side and gradually decreases toward the diagonal corner r2 is a wide range (range indicated by the solid arrow R1 in FIG. 9A). For example, the gas pressure distribution in a narrow range indicated by a two-dot chain line arrow R2 in FIG. 9A can be prevented.
Therefore, since a wide gas pressure distribution can be given to each thin plate 29, a pressure difference is surely generated in the upper and lower surfaces of each thin plate 29, and these thin plates 29 are made to have a peripheral surface 23 a of the rotating shaft 23. This makes it possible to accurately adjust the gas pressure for floating the thin plate.
[0090]
Next, an eighth embodiment of the present invention will be described with reference to FIG. The present embodiment corresponds to a modification of the sixth embodiment, and therefore, the description will focus on the differences from the sixth embodiment. The description of the same parts as those in the sixth embodiment will be omitted.
10A is a cross-sectional view of the leaf seal 25 as viewed from a cross section passing through the axis of the rotary shaft 23. FIGS. 10B and 10C are cross-sectional views of the leaf seal 25 as viewed from line EE. is there.
[0091]
As shown in FIG. 10 (b), in the present embodiment, an equal interval G is provided instead of the stepped portion 50 that is annularly continuous over the entire circumference described in the sixth embodiment. In this state, a stepped portion 50A (second stepped portion) composed of a plurality of annular divided plates 50a that are intermittently arranged so as to form a ring around the rotation shaft 23 along the low-pressure side plate 26. One feature (one stage) is that it is fixed to the low-pressure side plate 26. As shown in FIG. 10A, the step-shaped portion 50A is formed on the side of the low-pressure side plate 26 so as to protrude toward the thin plate 29 when viewed in a cross section passing through the axis of the rotary shaft 23. Is provided.
The step-shaped portion 50A (annular divided 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.
[0092]
In the present embodiment, since the gaps G serve as substitutes for the vent holes 51 of the seventh embodiment, the step shape in the gap space between the thin plates 29 and the low-pressure side plate 26 is used. The resistance to the gas flow between both the space on the inner periphery side in the rotation axis radial direction and the outer periphery side in the rotation shaft radial direction with the portion 50A as a boundary is reduced. Thereby, while ensuring the support of each thin plate 29 by the step-shaped portion 50A, it is possible to form a pressure distribution in the radial direction of the rotation axis in the gap space as if the step-shaped portion 50A does not exist. become.
[0093]
As a result, when a gas pressure from the high-pressure side plate 27 toward the low-pressure side plate 26 is applied to each thin plate 29, the top and bottom surfaces of the thin plates 29 facing the rotating shaft 23 and the high-pressure side plate 27. The gas pressure distribution in which the gas pressure is highest at the corner r1 located on the side of the gas and the gas pressure gradually decreases toward the diagonal corner r2 is a wide range (range indicated by the solid arrow R1 in FIG. 10A). For example, the gas pressure distribution in a narrow range indicated by a two-dot chain line arrow R2 in FIG.
Therefore, since a wide gas pressure distribution can be given to each thin plate 29, a pressure difference is surely generated in the upper and lower surfaces of each thin plate 29, and these thin plates 29 are made to have a peripheral surface 23 a of the rotating shaft 23. This makes it possible to accurately adjust the gas pressure for floating the thin plate.
[0094]
As a modification of the present embodiment, for example, as shown in FIG. 10 (c), the stepped portions 50A are arranged in two rounds (two steps) in a concentric manner with the rotation shaft 23 as an axis, or 3 Of course, a configuration (not shown) arranged in a circumference or more (three or more stages) is also possible.
[0095]
Next, a ninth embodiment of the present invention will be described with reference to FIG. The present embodiment corresponds to a modification of the sixth embodiment, and therefore, the description will focus on the differences from the sixth embodiment. The description of the same parts as those in the sixth embodiment will be omitted.
11A is a cross-sectional view of the leaf seal 25 as viewed from a cross section passing through the axis of the rotary shaft 23, and FIGS. 11B and 11C are cross-sectional views of FIG. is there.
[0096]
As shown in FIG. 11 (b), in this embodiment, instead of the stepped portion 50 that is annularly continuous over the entire circumference described in the sixth embodiment, a low pressure is applied from each thin plate 29 side. When the side plate 26 is viewed, the low pressure side plate 26 is arranged in a spiral shape from the inner peripheral side toward the outer peripheral side, and includes a plurality of spiral plates 50b having a gap G therebetween. A feature is that the stepped portion 50B (third stepped portion) is fixed to the low-pressure side plate 26. As shown in FIG. 11A, the step-shaped portion 50B is formed on the side of the low-pressure side plate 26 so as to protrude toward the thin plate 29 when viewed in a cross section passing through the axis of the rotary shaft 23. Is provided.
Each spiral plate 50b is inclined in the cross direction intersecting with each thin plate 29 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 fixed.
The step-shaped 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.
[0097]
As a modification of the present embodiment, for example, as shown in FIG. 11C, each spiral plate 50b has the same direction as each thin plate 29 when the low-pressure side plate 26 is viewed from the thin plate 29 side. Of course, it is also possible to employ a configuration in which it is fixed to the low-pressure side plate 26 in a state where it is inclined at different inclination angles (inclination angles with respect to the peripheral surface 23a of the rotating shaft 23). However, it is more preferable to incline in the cross direction shown in FIG. 11B because a large number of thin plates 29 can be supported by one spiral plate 50b.
[0098]
In the present embodiment, since the gaps G serve as substitutes for the vent holes 51 of the seventh embodiment, the step shape in the gap space 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 peripheral side in the rotational axis radial direction and the outer peripheral side in the radial direction of the rotational axis with the portion 50B as a boundary is reduced. Thereby, while ensuring the support of each thin plate 29 by the step-shaped portion 50B, it is possible to form a pressure distribution in the radial direction of the rotation axis in the gap space as if the step-shaped portion 50B does not exist. become.
[0099]
Thereby, when the gas pressure which goes to the low voltage | pressure side plate 26 from the high voltage | pressure side plate 27 is added to each thin plate 29, it is the front end side which opposes the rotating shaft 23 with respect to the upper and lower surfaces of these thin plates 29, and a high pressure side plate. The gas pressure distribution in which the gas pressure is highest at the corner r1 positioned on the side and the gas pressure gradually decreases toward the diagonal corner r2 is wide (range indicated by the solid arrow R1 in FIG. 11A). The gas pressure distribution in a narrow range can be prevented.
Therefore, since a wide gas pressure distribution can be given to each thin plate 29, a pressure difference is surely generated in the upper and lower surfaces of each thin plate 29, and these thin plates 29 are made to have a peripheral surface 23 a of the rotating shaft 23. This makes it possible to accurately adjust the gas pressure for floating the thin plate.
[0100]
Next, a tenth embodiment of the present invention will be described with reference to FIG. The present embodiment corresponds to a modification of the sixth embodiment, and therefore, the description will focus on the differences from the sixth embodiment. The description of the same parts as those 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 rotary shaft 23.
[0101]
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, it protrudes toward the low-pressure side plate 26. As described above, the step-shaped portion 50C (fourth step-shaped portion) provided on each thin plate 29 side is particularly characteristic.
Each step-shaped portion 50C is a protruding portion formed integrally with each thin plate 29, and a gap having the same size as the gap formed between the thin plates 29 is formed between them.
[0102]
In the present embodiment, since the gaps between the step-shaped portions 50C serve as substitutes for the vent holes 51 of the seventh embodiment, the gaps between the thin plates 29 and the low-pressure side plates 26. In the space, the resistance to the gas flow between the space on the inner peripheral side in the rotation axis radial direction and the outer peripheral side in the rotation shaft radial direction with the stepped portion 50C as a boundary is reduced. Thereby, while ensuring the support of each thin plate 29 by the step-shaped portion 50C, it is possible to form a pressure distribution in the radial direction of the rotation axis in the gap space as if the step-shaped portion 50C does not exist. become.
[0103]
As a result, when a gas pressure from the high-pressure side plate 27 toward the low-pressure side plate 26 is applied to each thin plate 29, the top and bottom surfaces of the thin plates 29 facing the rotating shaft 23 and the high-pressure side plate 27. A gas pressure distribution in which the gas pressure is highest at the corner r1 located on the side and gradually decreases toward the diagonal corner r2 is formed in a wide range (range indicated by the solid arrow R1 in FIG. 12). For example, the gas pressure distribution in a narrow range indicated by the two-dot chain line arrow R2 in FIG. 12 can be prevented.
Therefore, since a wide gas pressure distribution can be given to each thin plate 29, a pressure difference is surely generated in the upper and lower surfaces of each thin plate 29, and these thin plates 29 are made to have a peripheral surface 23 a 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, it is not necessary to process or attach to the low-pressure side plate 26 only by changing the shape of each thin plate 29, so that there is an effect that the merit is great in terms of manufacturing cost.
[0104]
Next, an eleventh embodiment of the present invention will be described with reference to FIG. The present embodiment corresponds to a modification of the sixth embodiment, and therefore, the description will focus on the differences from the sixth embodiment. The description of the same parts as those in the sixth embodiment will be omitted.
FIG. 13 is a cross-sectional view of the leaf seal 25 as seen from a cross section passing through the axis of the rotary shaft 23.
[0105]
As shown in FIG. 13, in the present embodiment, the annular stepped portion 50 (first stepped portion) described in the sixth embodiment extends along the radial direction of the low-pressure side plate 26. It is particularly characteristic that it is continuously formed up to the position of the casing 24. That is, the step-shaped portion 50 of the present embodiment is continuous to the base position (base) of the low-pressure side plate 26, which is a connection portion between the casing 24 and the low-pressure side plate 26, when viewed in the cross section of FIG. Wide. In the normal operation state, the step-shaped portion 50 has a state in which a surface facing each thin plate 29 is not in direct contact with each thin plate 29 and a minute gap is formed between the two. It has become. According to this step-shaped portion 50, by restraining the displacement or deformation of each thin plate 29, it is possible to prevent the low-pressure side gap 31 from becoming smaller than the gap dimension t2, and easily maintain the predetermined gap dimension. Is possible.
[0106]
According to the leaf seal 25 (shaft seal mechanism) and the gas turbine equipped with the leaf seal 25 of the present embodiment described above, the position of each thin plate 29 is on the low pressure side plate 26 side by providing the step-shaped portion 50. The thin plate 29 is supported by the step-shaped portion 50 even if it approaches, so that the approach is prevented. Therefore, from the assembly error during assembly of the shaft seal mechanism and the high pressure side during operation. Even if the thin plates 29 are deformed by the fluid pressure toward the low pressure side, the gaps between the thin plates 29 and the low pressure side plates 26 can be maintained at a predetermined gap dimension t2.
[0107]
That is, since each thin plate 29 and the high-pressure side plate 27 and the low-pressure side plate 26 can be formed with predetermined gap sizes, even if pressure fluctuations occur between the high-pressure side and the low-pressure side. Since each gap dimension is less likely to change, the applied seal differential pressure range can be expanded. Further, as described above, since a minute gap is formed between the stepped portion 50 and each thin plate 29, the clearance tolerance between the high pressure side plate 27 and the low pressure side plate 26 and each thin plate 29 is loosened. Can be designed and the processing cost can be reduced.
In addition to this, it goes without saying that the same effects as those described in the sixth embodiment can be obtained.
[0108]
Next, a twelfth embodiment of the present invention will be described with reference to FIG. The present embodiment corresponds to a modification of the eleventh embodiment, and therefore, differences from the eleventh embodiment will be mainly described. The description of the same parts as those of the eleventh embodiment is omitted.
FIG. 14 is a cross-sectional view of the leaf seal 25 as viewed from a cross section passing through the axis of the rotary shaft 23.
[0109]
As shown in FIG. 14, in the present embodiment, in addition to the step-shaped portion 50 described in the eleventh embodiment, the third embodiment will be described with reference to FIG. The high pressure side clearance fine adjustment thin plate 35 is particularly characterized in that it is disposed in the clearance between the high pressure side plate 27 and the thin plate 29.
According to this configuration, when a gas pressure from the high-pressure side plate 27 toward the low-pressure side plate 26 is applied to each thin plate 29, the top and bottom surfaces of the thin plates 29 are on the tip side facing the rotary shaft 23 and are high pressure. It is possible to form a gas pressure distribution in which the gas pressure is highest at the corner portion r1 located on the side plate 27 side and gradually decreases toward the diagonal corner portion r2.
According to the leaf seal 25 (shaft seal mechanism) of the present embodiment described above and the gas turbine equipped with the same, the same operational effects as those of the eleventh embodiment and the third embodiment can be obtained. Is possible.
[0110]
Next, a thirteenth embodiment of the present invention will be described with reference to FIG. Since this embodiment corresponds to a modification of the twelfth embodiment, the description will focus on the differences from the twelfth embodiment. The description of the same parts as those in the twelfth embodiment is omitted.
FIG. 15 is a cross-sectional view of the leaf seal 25 as viewed from a cross section passing through the axis of the rotary shaft 23.
[0111]
As shown in FIG. 15, in the present embodiment, the high pressure side plate 27 of the twelfth embodiment has a pressure guide hole 100 penetrating the high pressure side plate 27 in the axial direction of the rotary shaft 23 in the circumferential direction. This is particularly characteristic in that a plurality are provided.
According to this configuration, a part of the gas in the high-pressure side region can be added to the high-pressure side clearance fine adjustment thin plate 35 so as to pass through the high-pressure side plate 27 through the pressure guide holes 100. The side clearance fine adjustment thin plate 35 can be bent more effectively. Therefore, the operation of the twelfth embodiment can be obtained more reliably.
According to the leaf seal 25 (shaft seal mechanism) and the gas turbine provided with the leaf seal 25 of the present embodiment described above, the effects of the twelfth embodiment can be obtained more reliably.
[0112]
The shaft sealing mechanism of the present invention and the first to thirteenth embodiments of the gas turbine provided with the shaft sealing mechanism have been described above. As this gas turbine, the turbine shaft is rotated using combustion gas. In addition to a general gas turbine that obtains power, an aircraft gas turbine engine and the like are also included. In addition, 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, the above-described gap dimension adjusting means 50, 50A, 50B, 50C are combined with the shaft seal mechanism (leaf seal 25) of the third and fourth embodiments and the gas turbine provided with the shaft seal mechanism. Can also be adopted. In this case as well, it is needless to say that the same effect can be obtained by adopting the gap size adjusting means 50, 50A, 50B, 50C.
[0113]
【The invention's effect】
Claims 1 to 1 of the present invention20A shaft seal mechanism according to any one of claims 1 to 3, or a claim21According to the described gas turbine, the angle between the thin plate and the rotating shaft peripheral surface is made acute, and the pressure adjusting means is provided so that buoyancy is applied to the thin plate, so that the rotating shaft when passing through the resonance point, etc. When the vibration is large, the thin plate attached at an acute angle is deformed and the contact with the rotating shaft is relaxed. In addition, the rated pressure is due to the dynamic pressure effect caused by the rotation of the rotating shaft. Further, due to the pressure load difference generated in the thin plate, the tip of the thin plate is lifted from the surface of the rotating shaft, and contact with the rotating shaft is avoided. Therefore, excessive heat generation and wear due to contact between the thin plate and the rotating shaft can be prevented. Furthermore, since heat generation due to contact between the thin plate and the rotating shaft is prevented, occurrence of vibration due to thermal balance in the rotating shaft can be avoided.
[0114]
Further, by using a thin plate for the seal member, the fixing portion for the casing is enlarged as compared with the conventional wire, so that the thin plate is firmly fixed to the casing. Thereby, the drop-off from the casing such as the drop-out of the wire in the conventional brush seal can be prevented.
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, making it difficult to cause deformation in the differential pressure direction compared to conventional brush seals. Can be improved.
[0115]
In addition, it is possible to arrange the thin plates more closely by making the gap between the thin plates equal on the outer peripheral side and inner peripheral side, and the gap between the thin plate tip and the rotating shaft is compared with non-contact type labyrinth seals etc. Can be dramatically reduced. Thereby, it becomes possible to reduce the amount of gas leakage, and when this is used for a gas turbine, the performance can be improved.
Accordingly, claims 1 to 1 described above.20A shaft seal mechanism according to any one of claims 1 to 3, or a claim21According to the described gas turbine, it is possible to reduce the amount of gas leakage from the high-pressure side to the low-pressure side and to improve wear resistance.
[0116]
Furthermore, the claim14-17Or any of the above claims20The shaft seal mechanism according to claim 1, or the shaft seal mechanism.21According to the described gas turbine, the resistance to the gas flow flowing between both 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 is reduced. Thereby, it is possible to form a pressure distribution in the radial direction of the rotation axis in the gap space between the thin plate and the low-pressure side plate while ensuring the support of the thin plate.
Therefore, when gas pressure directed from the high-pressure side plate to the low-pressure side plate is applied to the thin plate, the corner portion located on the tip side facing the rotation axis and on the high-pressure side plate side with respect to the upper and lower surfaces of the thin plate. Since the gas pressure distribution range in which the gas pressure is highest and the gas pressure gradually decreases toward the diagonal can be made wider, it is possible to reliably generate a pressure difference between the upper and lower surfaces of the thin plate, It is possible to accurately adjust the gas pressure for ascending the thin plate so that the thin plate is floated from the circumferential surface of the rotating shaft.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing a first embodiment of a gas turbine provided with a shaft seal mechanism according to the present invention.
FIG. 2 is a perspective view of a leaf seal (shaft seal mechanism) according to the embodiment.
FIG. 3 is a view showing a leaf seal of the same embodiment, wherein (a) is a cross-sectional view seen from a cross-section passing through the axis of the rotary shaft, and (b) is a cross-sectional view taken along line BB. FIG.
FIG. 4 is a diagram showing a second embodiment of a shaft seal mechanism (leaf seal) according to the present invention, and is a cross-sectional view seen from a cross section passing through the axis of a rotation shaft.
FIGS. 5A and 5B are diagrams showing a third embodiment of a shaft seal mechanism (leaf seal) according to the present invention, wherein FIGS. 5A and 5B are cross-sectional views as seen from a cross section passing through an axis of a rotary shaft; FIGS. is there.
6A and 6B are diagrams showing a fourth embodiment of a shaft seal mechanism (leaf seal) according to the present invention, in which FIG. 6A is a perspective view thereof, and FIG. 6B is a perspective view showing a modified example thereof. It is.
FIG. 7 is a view showing a fifth embodiment of a shaft seal mechanism (leaf seal) according to the present invention, and is a cross-sectional view seen from a cross section passing through the axis of a rotation shaft.
FIG. 8 is a view showing a sixth embodiment of a shaft seal mechanism (leaf seal) according to the present invention, in which (a) is a cross-sectional view as seen from a cross section passing through the axis of the rotary shaft; ) Is a cross-sectional view of FIG.
FIG. 9 is a view showing a seventh embodiment of a shaft seal mechanism (leaf seal) according to the present invention, in which (a) is a cross-sectional view as seen from a cross section passing through the axis of the rotary shaft; ) Is a cross-sectional view of (a) as seen from line DD.
FIG. 10 is a view showing an eighth embodiment of a shaft seal mechanism (leaf seal) according to the present invention, in which (a) is a cross-sectional view as seen from a cross section passing through the axis of the rotary shaft; ), (C) are cross-sectional views of (a) as seen from line EE.
FIG. 11 is a diagram showing a ninth embodiment of a shaft seal mechanism (leaf seal) according to the present invention, in which (a) is a cross-sectional view as seen from a cross section passing through the axis of the rotary shaft; ), (C) are cross-sectional views of (a) taken along 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 rotary shaft.
FIG. 13 is a diagram showing an eleventh 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 the axis of a rotary shaft.
FIG. 14 is a diagram showing a twelfth embodiment of a shaft seal mechanism (leaf seal) according to the present invention, and is a cross-sectional view seen from a cross section passing through the axis of a rotary shaft.
FIG. 15 is a diagram showing a thirteenth embodiment of a shaft seal mechanism (leaf seal) according to the present invention, and is a cross-sectional view seen from a cross section passing through the axis of a rotary shaft.
FIGS. 16A and 16B are diagrams showing an example of a conventional shaft seal mechanism, in which FIG. 16A is a cross-sectional view as seen from a cross section passing through the axis of a rotary shaft, and FIG. 16B is from a line AA in FIG. FIG.
FIG. 17 is a perspective view showing another example of a conventional shaft seal mechanism.
[Explanation of symbols]
23 ... Rotating shaft
23a ... peripheral surface
23e ... Rotor blade
24 ... Casing
25 ... Leaf seal (shaft seal mechanism)
26 ... Low pressure side plate
26a ... Ventilation hole
27, 35 ... high-pressure side plate, high-pressure side clearance fine adjustment thin plate (flexible plate)
29 ... Thin plate
29a ... upper surface
29b ... lower 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 ... Length of the low-pressure side plate (length of the low-pressure side plate in the rotational axis radial direction)
34 ... Length of the high-pressure side plate (length of the high-pressure side plate in the radial direction of the rotation axis)
41, 42 ... Flexible plate with slit
41a, 42a ... slit
50... Clearance dimension adjusting means, first step shape portion
50A: Clearance dimension adjusting means, second step shape portion
50B: Clearance dimension adjusting means, third step shape portion
50C: Clearance dimension adjusting means, fourth step shape portion
50a ... annular dividing plate
50b ... spiral board
51 ... Ventilation hole
100 ... Induction hole
G ... Interval
g ・ ・ ・ Gas
r1 ... Corner
r2 ... Corner (diagonal)

Claims (21)

A plurality of flexible thin plates having a width in the axial direction of the rotating shaft, the tip sliding on the peripheral surface of the rotating shaft, and having a gap between them and the outer peripheral base end fixed to the casing side, The outer periphery of the rotating shaft is provided in multiples such that the outer periphery of the rotating shaft can be sealed in the circumferential direction of the rotating shaft, the thin plate and the peripheral surface of the rotating shaft form an acute angle, It is a shaft seal mechanism provided with side plates,
A cross-sectional view of the thin plate in a virtual plane perpendicular to the width direction thereof, a surface facing the rotation axis of the thin plate as a lower surface, and a back side thereof as an upper surface, from the high-pressure side plate to the low-pressure side plate with respect to the thin plate Gas pressure adjusting means is provided to increase the gas pressure applied to the lower surface rather than the gas pressure applied to the upper surface at an arbitrary position along the cross section of the thin plate when a gas pressure is applied .
The shaft seal mechanism is characterized in that the gas pressure adjusting means is a gap size adjustment that makes a gap between the thin plate and the low-pressure side plate larger than a gap between the thin plate and the high-pressure side plate. . A plurality of flexible thin plates having a width in the axial direction of the rotating shaft, the tip sliding on the peripheral surface of the rotating shaft, and having a gap between them and the outer peripheral base end fixed to the casing side, The outer periphery of the rotating shaft is provided in multiples such that the outer periphery of the rotating shaft can be sealed in the circumferential direction of the rotating shaft, the thin plate and the peripheral surface of the rotating shaft form an acute angle, It is a shaft seal mechanism provided with side plates,
When a gas pressure from the high-pressure side plate toward the low-pressure side plate is applied to the thin plate, the gas is most gas at the corner located on the tip side and on the high-pressure side plate with respect to the upper and lower surfaces of the thin plate. pressure is high and the gas pressure adjusting means for forming a gas pressure distribution gradually weakens the gas pressure toward a diagonally disposed,
The shaft seal mechanism is characterized in that the gas pressure adjusting means is a gap size adjustment that makes a gap between the thin plate and the low-pressure side plate larger than a gap between the thin plate and the high-pressure side plate. . A plurality of flexible thin plates having a width in the axial direction of the rotating shaft, the tip sliding on the peripheral surface of the rotating shaft, and having a gap between them and the outer peripheral base end fixed to the casing side, The outer periphery of the rotating shaft is provided in multiples such that the outer periphery of the rotating shaft can be sealed in the circumferential direction of the rotating shaft, the thin plate and the peripheral surface of the rotating shaft form an acute angle, It is a shaft seal mechanism provided with side plates,
  A cross-sectional view of the thin plate in a virtual plane perpendicular to the width direction thereof, a surface facing the rotation axis of the thin plate as a lower surface, and a back side thereof as an upper surface, and from the high-pressure side plate to the low-pressure side plate with respect to the thin plate Gas pressure adjusting means is provided to increase the gas pressure applied to the lower surface rather than the gas pressure applied to the upper surface at an arbitrary position along the cross section of the thin plate when a gas pressure is applied.
  The gas pressure adjusting means is a side plate size adjustment in which the length dimension of the low pressure side plate in the radial direction of the rotation axis is shorter than the length dimension of the high pressure side plate in the radial direction of the rotation axis. Shaft seal mechanism. A plurality of flexible thin plates having a width in the axial direction of the rotary shaft, the tip sliding on the peripheral surface of the rotary shaft, and having a gap between them and the outer peripheral side proximal end fixed to the casing side, The outer periphery of the rotating shaft is provided in multiples such that the outer periphery of the rotating shaft can be sealed in the circumferential direction of the rotating shaft, the thin plate and the peripheral surface of the rotating shaft form an acute angle, A shaft seal mechanism provided with a side plate,
When a gas pressure from the high-pressure side plate toward the low-pressure side plate is applied to the thin plate, the gas is most gas at the corner located on the tip side and on the high-pressure side plate with respect to the upper and lower surfaces of the thin plate. A gas pressure adjusting means for forming a gas pressure distribution in which the pressure is high and the gas pressure gradually decreases toward the diagonal is provided,
The gas pressure adjusting means is a side plate size adjustment in which the length dimension of the low-pressure side plate in the radial direction of the rotational axis is shorter than the length dimension of the high-pressure side plate in the radial direction of the rotary shaft. Shaft seal mechanism. Having a width in the axial direction of the rotating shaft slides on the peripheral surface of the tip is the rotary shaft, a thin plate having a plurality of flexible outer peripheral side proximal end with a gap is fixed to the casing side each other The outer periphery of the rotating shaft is provided in multiples so that the outer periphery of the rotating shaft can be sealed in the circumferential direction of the rotating shaft, the thin plate and the peripheral surface of the rotating shaft form an acute angle, It is a shaft seal mechanism provided with a high-pressure side plate,
A cross-sectional view of the thin plate in a virtual plane perpendicular to the width direction thereof, a surface facing the rotation axis of the thin plate as a lower surface, and a back side thereof as an upper surface, from the high-pressure side plate to the low-pressure side plate with respect to the thin plate Gas pressure adjusting means is provided for increasing the gas pressure applied to the lower surface than the gas pressure applied to the upper surface at an arbitrary position along the cross section of the thin plate when a gas pressure is applied to the thin plate,
The shaft seal mechanism, 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 direction of the rotation axis. A plurality of flexible thin plates having a width in the axial direction of the rotating shaft, the tip sliding on the peripheral surface of the rotating shaft, and having a gap between them and the outer peripheral base end fixed to the casing side, The outer periphery of the rotating shaft is provided in multiples such that the outer periphery of the rotating shaft can be sealed in the circumferential direction of the rotating shaft, the thin plate and the peripheral surface of the rotating shaft form an acute angle, It is a shaft seal mechanism provided with side plates,
  When a gas pressure from the high-pressure side plate toward the low-pressure side plate is applied to the thin plate, the gas is the most gas at the corner located on the tip side and on the high-pressure side plate with respect to the upper and lower surfaces of the thin plate. A gas pressure adjusting means for forming a gas pressure distribution in which the pressure is high and the gas pressure gradually decreases toward the diagonal is provided,
  The shaft seal mechanism, wherein the gas pressure adjusting means is a flexible plate that is disposed on a high pressure side of the thin plate and has flexibility in the direction of the rotation axis. A plurality of flexible thin plates having a width in the axial direction of the rotating shaft, the tip sliding on the peripheral surface of the rotating shaft, and having a gap between them and the outer peripheral base end fixed to the casing side, The outer periphery of the rotating shaft is provided in multiples such that the outer periphery of the rotating shaft can be sealed in the circumferential direction of the rotating shaft, the thin plate and the peripheral surface of the rotating shaft form an acute angle, It is a shaft seal mechanism provided with side plates,
  A cross-sectional view of the thin plate in a virtual plane perpendicular to the width direction thereof, a surface facing the rotation axis of the thin plate is a lower surface, and a back side thereof is an upper surface, and from the high pressure side plate to the low pressure side plate with respect to the thin plate Gas pressure adjusting means is provided to increase the gas pressure applied to the lower surface rather than the gas pressure applied to the upper surface at an arbitrary position along the cross section of the thin plate when a gas pressure is applied.
  The gas pressure adjusting means is a flexible plate with slits that is arranged on the high pressure side of the thin plate, has flexibility in the direction of the rotation axis, and has two or more slits formed on the entire circumference thereof. A shaft seal mechanism characterized by that. A plurality of flexible thin plates having a width in the axial direction of the rotating shaft, the tip sliding on the peripheral surface of the rotating shaft, and having a gap between them and the outer peripheral base end fixed to the casing side, The outer periphery of the rotating shaft is provided in multiples such that the outer periphery of the rotating shaft can be sealed in the circumferential direction of the rotating shaft, the thin plate and the peripheral surface of the rotating shaft form an acute angle, It is a shaft seal mechanism provided with side plates,
  When a gas pressure from the high-pressure side plate toward the low-pressure side plate is applied to the thin plate, the gas is the most gas at the corner located on the tip side and on the high-pressure side plate with respect to the upper and lower surfaces of the thin plate. A gas pressure adjusting means for forming a gas pressure distribution in which the pressure is high and the gas pressure gradually decreases toward the diagonal is provided,
  The gas pressure adjusting means is a flexible plate with slits that is arranged on the high pressure side of the thin plate, has flexibility in the direction of the rotation axis, and has two or more slits formed on the entire circumference thereof. A shaft seal mechanism characterized by that. A plurality of flexible thin plates having a width in the axial direction of the rotating shaft, the tip sliding on the peripheral surface of the rotating shaft, and having a gap between them and the outer peripheral base end fixed to the casing side, The outer periphery of the rotating shaft is provided in multiples such that the outer periphery of the rotating shaft can be sealed in the circumferential direction of the rotating shaft, the thin plate and the peripheral surface of the rotating shaft form an acute angle, It is a shaft seal mechanism provided with side plates,
  A cross-sectional view of the thin plate in a virtual plane perpendicular to the width direction thereof, a surface facing the rotation axis of the thin plate is a lower surface, and a back side thereof is an upper surface, and from the high pressure side plate to the low pressure side plate with respect to the thin plate Gas pressure adjusting means is provided to increase the gas pressure applied to the lower surface rather than the gas pressure applied to the upper surface at an arbitrary position along the cross section of the thin plate when a gas pressure is applied.
  The shaft seal mechanism, 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. A plurality of flexible thin plates having a width in the axial direction of the rotating shaft, the tip sliding on the peripheral surface of the rotating shaft, and having a gap between them and the outer peripheral base end fixed to the casing side, The outer periphery of the rotating shaft is provided in multiples such that the outer periphery of the rotating shaft can be sealed in the circumferential direction of the rotating shaft, the thin plate and the peripheral surface of the rotating shaft form an acute angle, It is a shaft seal mechanism provided with side plates,
  When a gas pressure from the high-pressure side plate toward the low-pressure side plate is applied to the thin plate, the gas is the most gas at the corner located on the tip side and on the high-pressure side plate with respect to the upper and lower surfaces of the thin plate. A gas pressure adjusting means for forming a gas pressure distribution in which the pressure is high and the gas pressure gradually decreases toward the diagonal is provided,
  The shaft seal mechanism, 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. A plurality of flexible thin plates having a width in the axial direction of the rotating shaft, the tip sliding on the peripheral surface of the rotating shaft, and having a gap between them and the outer peripheral base end fixed to the casing side, A shaft sealing mechanism in which the outer periphery of the rotating shaft is provided in a multiplexable manner 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 shaft seal mechanism characterized in that a gas passage space is formed between the thin plate and the low-pressure side plate to allow gas to pass from the high-pressure side to the low-pressure side. In the shaft seal mechanism according to any one of claims 1, 2, 5 to 8,
  Between the low-pressure side plate and the thin plate, when the thin plate tries to approach the low-pressure side plate, the thin plate is supported and the gap dimension between the low-pressure side plate and the thin plate is maintained. A shaft seal mechanism provided with a gap dimension adjusting means. The shaft seal mechanism according to claim 12,
  The gap dimension adjusting means is a first step-shaped portion provided on the low-pressure side plate so as to protrude toward the thin plate,
  The shaft sealing mechanism, wherein the first step-shaped portion has an annular shape around the rotation axis along the low-pressure side plate. The shaft seal mechanism according to claim 13,
  The shaft seal mechanism according to claim 1, wherein the first step-shaped portion is formed with a vent hole communicating the annular inner and outer circumferential spaces. The shaft seal mechanism according to claim 12,
  The gap dimension adjusting means is a second step-shaped portion provided on the low-pressure side plate so as to protrude toward the thin plate,
  The second step-shaped portion is composed of a plurality of annular dividing plates arranged intermittently so as to form an annular shape around the rotation axis along the low-pressure side plate in a state of being spaced apart from each other. Shaft seal mechanism. The shaft seal mechanism according to any one of claims 13 to 15,
  The shaft sealing mechanism according to claim 1, wherein the first or second step-shaped portion is provided with a plurality of steps concentrically with the rotating shaft as an axis. The shaft seal mechanism according to claim 12,
  The gap dimension adjusting means is a third step-shaped portion provided on the low-pressure side plate side so as to protrude toward the thin plate side,
  The third stepped portion comprises a plurality of spiral plates arranged in a spiral shape 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. This A shaft seal mechanism characterized in that a space is provided between the spiral plates. The shaft seal mechanism according to claim 13,
  The shaft seal mechanism according to claim 1, wherein the first step-shaped portion is formed up to a position of the casing along a radial direction of the low-pressure side plate. The shaft seal mechanism according to claim 18,
  The shaft sealing mechanism, wherein the high-pressure side plate is formed with a pressure introduction hole penetrating the high-pressure side plate in the axial direction of the rotary shaft. The shaft seal mechanism according to claim 12,
  The shaft seal mechanism, wherein the gap dimension adjusting means is a fourth step-shaped portion provided on the thin plate side so as to protrude toward the low-pressure side plate. A gas turbine that generates heat by converting the thermal energy of the gas into mechanical rotational energy by guiding high-temperature and high-pressure gas to the casing and spraying it on the rotor blades of a rotating shaft that is rotatably supported inside the casing. In
  A gas turbine comprising the shaft seal mechanism according to any one of claims 1 to 20.

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