JP4625438B2 - Shaft seal device for rotating machinery - Google Patents

Description

  The present invention is applied to a fluid seal on the outer periphery of a rotating shaft, such as a gas turbine or a steam turbine, and is used for a rotating machine that seals a fluid flowing along the axial direction in a gap between the outer periphery of the rotating shaft of the rotating machine and a case member. The present invention relates to a shaft seal device.

  In gas turbines, steam turbines, etc., instead of labyrinth seals that have been used in recent years, a leaf made of a thin plate is rotated at the fluid seal between the outer periphery of the rotating shaft of the turbine rotor and the inner periphery of the stationary blade. A large number are arranged along the circumferential direction of the shaft, the outer peripheral portion of the leaf is fixed to the stationary blade (case member), and the inner peripheral portion is used as a free end, and a fluid is provided between the free end and the outer periphery of the rotating shaft. A leaf-type shaft seal unit in which a high-pressure side plate and a low-pressure side plate are formed opposite to each other in the axial direction so as to form a seal portion and suppress axial fluid flow passing through the leaf on both axial sides of the leaf Came to be used.

As one of the shaft seal devices for a rotary machine provided with such a leaf-type shaft seal unit, a technique of Patent Document 1 (Japanese Patent Laid-Open No. 2002-13647) relating to the applicant's application is provided. FIG. 13 is a perspective view of a main part of the shaft seal unit in Patent Document 1.
In FIG. 13, reference numeral 100 denotes a shaft seal unit, which is configured as follows.
7 rotary shaft 1 a leaf made of sheet metal, the leaf 1 is disposed a large number along the circumferential direction of the rotating shaft 7, the back spacer 9 an outer peripheral portion of the case member 5, such as vanes each leaf 1 The inner peripheral part is fixed as a free end, and a fluid seal part is formed between the free end and the outer periphery of the rotary shaft 7.
On both sides in the axial direction of the leaf, a high-pressure side plate 2 and a low-pressure side plate 3 that suppress the axial fluid flow G that passes through the leaf are disposed facing each other in the axial direction with the leaf 1 in between.

JP 2002-13647 A

FIG. 11 is a configuration diagram of the shaft seal unit as viewed in the direction of the rotational axis, and FIG. 12 is an enlarged view of a portion Z in FIG. FIG. 14 is a view taken along the arrow YY in FIG. 12 showing the form of the dividing portion of the shaft seal unit.
11 to 12, reference numeral 100 denotes a shaft seal unit configured as shown in FIG. 13 (the same members as those shown in FIG. 13 are denoted by the same reference numerals). As shown in FIG. In general, the rotary shaft 7 is divided into 2 to 8 parts in the circumferential direction for assembly to the outer periphery. Reference numeral 6 denotes a dividing gap formed in the dividing portion.

Therefore, in such shaft seal unit 100, as indicated by F arrows in FIG. 14, through the split gap 6 of the divided portion, the low pressure side plate from the high-pressure side facing the high-pressure side plate 2 of the shaft seal unit 100 Leakage of the fluid flowing to the low pressure side where 3 faces is generated. Due to the leakage of the fluid, the pressure distribution between the leaves 1 on the side close to the dividing gap 6 (H portion in FIG. 14) becomes a higher level pressure distribution than the pressure distribution on the side away from the dividing gap 6.
For this reason, in such a shaft seal unit 100, the floating characteristics of the leaf 1 on the side close to the dividing gap 6 (H portion in FIG. 14) are reduced, and the rotational shaft 7 outer periphery can increase the rotational speed of the rotational shaft 7. A proper gap cannot be formed between the leaf 1 and the contact between the leaf 1 and the outer periphery of the rotating shaft 7 during high rotation causes fluid leakage due to damage to the leaf 1 or defective sealing of the fluid seal at the tip of the leaf 1. There are problems such as being easy.

  In view of the problems of the prior art, the present invention suppresses the fluid leakage through the dividing gap formed in the dividing portion of the shaft seal unit, reduces the floating characteristics of the leaf due to the fluid leakage, and the accompanying leaf It is an object of the present invention to provide a shaft seal device for a rotary machine that avoids the occurrence of fluid leakage due to breakage or defective sealing of a fluid seal portion at the tip of a leaf.

The present invention achieves such an object, and is a shaft sealing device for a rotating machine that seals a fluid flowing along the axial direction between the outer periphery of the rotating shaft of the rotating machine and a case member, and includes a thin plate. A large number of leaves are arranged along the circumferential direction of the rotating shaft, the outer peripheral portion of the leaf is fixed to the case member, and the inner peripheral portion is a free end, and a fluid seal is provided between the free end and the outer periphery of the rotating shaft. to form a part rotation, equipped with a shaft seal unit comprising a high-pressure side plate and the low pressure side plate suppressing the axial fluid flow through the leaves in the axial direction on both sides of the leaf was placed to face in the axial direction In the shaft seal device of a machine, the shaft seal unit inserts a plurality of split portion shims whose outer peripheral portions are fixed to the case member into a split gap formed by splitting in the circumferential direction of the rotating shaft. Rutotomoni, by inserting the axial bent portion formed by bending the axial direction of the high-pressure side plate only the end the rotation axis of the split gap, and the said dividing portion shim axial bent portion It is characterized in that it is formed by stacking and closing the dividing gap.

According to this invention, the shaft seal unit is inserted into the dividing gap of the circumferential dividing portion of the rotating shaft with a plurality of dividing portion shims whose outer peripheral portions are fixed to the case member, and then only the high-pressure side plate. Since the axially bent portion formed by bending the end portion of the rotating shaft in the axial direction of the rotating shaft is laminated with the divided portion shim so as to block the divided gap, fluid flowing from the high pressure side toward the divided gap The flow into the divided gap is completely blocked by blocking the flow path at the axially bent portion at the end of the high-pressure side plate and blocking the flow path by a plurality of divided portion shims stacked on the axially bent portion. It becomes possible to do.

Therefore, according to this invention, it is possible to reliably avoid the leakage of the fluid flowing from the high pressure side to the low pressure side through the dividing gap, and the nonuniform pressure distribution due to the fluid leakage and the floating characteristics of the leaf due to this. Can be prevented.
As a result, it is possible to avoid the occurrence of fluid leakage due to the breakage of the leaf and the poor sealing of the fluid seal portion at the tip of the leaf due to such a decrease in the floating characteristics.
Further, according to the invention, the shaft sealing device having the above-described effect can be obtained by diverting other components to existing components only by changing the shape of the high-pressure side plate by bending only the high-pressure side plate. can get.

Further, the present invention provides the shaft seal device for the rotary machine, wherein the shaft seal unit includes a plurality of sheets whose outer peripheral portions are fixed to the case member in divided gaps formed by dividing in the circumferential direction of the rotary shaft. the dividing unit by inserting a shim with closing the split gap at the base of the dividing portion shim, the divided portion by bending the shims in the circumferential direction to form a circumferential bent portion, said circumferential direction bent portions The high-pressure side plate is configured to be in fluid-tight contact with the end portion of the high-pressure side plate, and the circumferentially bent portion of the split portion shim is overlapped with the end portion side surface of the high-pressure side plate .

According to the invention, the dividing gap in the circumferential direction divided portion of the rotary shaft, closes the split gap at the base of the dividing portion shim by inserting a plurality of divided portions shims outer peripheral portion is fixed to the case member Above,
Since the circumferentially bent portion formed by bending the dividing portion shim in the circumferential direction is in fluid-tight contact with the end portion of the high-pressure side plate, fluid flowing from the high-pressure side to the dividing gap is allowed to flow into the dividing gap of the dividing portion shim. a flow path blocking at the base closing the, by the flow path blocking by fixing the end portion of the circumferential bent portion and the high-pressure side plate of the split part shim, be completely blocked from flowing into the divided gap It becomes possible.
Therefore, it is possible to reliably avoid the leakage of the fluid flowing from the high pressure side through the dividing gap to the low pressure side, and to prevent the nonuniform pressure distribution due to the fluid leakage and the deterioration of the floating characteristics of the leaf due to this. Therefore, it is possible to avoid the occurrence of fluid leakage due to the breakage of the leaf accompanying the deterioration of the floating characteristics and the seal failure of the fluid seal portion at the tip of the leaf.

In particular, the present invention, a circumferential bent portion of the divided portions shim, in order to have a structure in which Ru superimposed on the end portion side of the high-pressure side plate, only subjected to bending in the circumferential direction in the split portion shim, The shaft sealing device having the above-described effects can be obtained by diverting other components to existing components.
Furthermore, the dividing unit shim may both deformation during deformation of the leaf to the circumferential direction, that is, since the circumferential bent portion of the divided portions shim can slide along the high-pressure side plate, according to claim 1 The deformation of the leaf is restrained by the high-pressure side plate integrally having such an axial bent portion, and the leaf sealing function is not hindered.

In the present invention, the following configuration is specifically preferred.
( 1 ) A side fitting groove having a predetermined length is formed along the circumferential direction on the outer surface of the end portion of the high-pressure side plate, and the circumferentially bent portion of the divided portion shim is used as the side fitting groove. The circumferentially bent portion is overlaid on the bottom surface of the base plate so that it fits in the side fitting groove.
If comprised in this way, a bending process to the circumferential direction will be given to a division part shim, and only the side part fitting groove will be carved in the end of a high voltage side plate, and other components will be replaced with existing parts. By diverting, a shaft seal device having the above-described effects can be obtained.
The split part shim can be deformed together when the leaf is deformed in the circumferential direction, i.e., the circumferentially bent part of the split part shim can slide along the side fitting groove. The deformation of the leaf is restrained by the high-pressure side plate integrally having such an axial bent portion, and the leaf sealing function is not hindered.
Moreover, since the circumferential direction bending part of the division part shim is stored in the side part fitting groove of the high-pressure side plate, the circumferential direction bending part of the division part shim is overlapped with the high-pressure side plate from the existing product. There is no increase in dimension in the axial direction on the high-pressure side, and the split part shim can be installed in the same axial direction as existing products.

( 2 ) An internal fitting groove having a predetermined length is formed along the circumferential direction inside the end portion of the high-pressure side plate, and the circumferentially bent portion of the divided portion shim is inserted into the internal fitting groove. To do.
If constituted in this way, the folding part shim is subjected to a bending process in the circumferential direction, and only an internal fitting groove having a predetermined length is formed in the end part of the high-pressure side plate along the circumferential direction. The shaft sealing device having the above-described effects can be obtained by diverting other components to existing components.
The split part shim can be deformed together when the leaf is deformed in the circumferential direction, that is, the circumferentially bent part of the split part shim can slide in the internal fitting groove. The high pressure side plate integrally having the axially bent portion restrains the deformation of the leaf and does not hinder the leaf sealing function.
Further, since the circumferentially bent portion of the dividing portion shim is housed in the internal fitting groove carved in the inside of the high-pressure side plate, the circumferentially bent portion of the dividing portion shim is overlapped on the high-pressure side plate. There is no increase in the axial dimension on the high-pressure side from the existing product, and the split part shim can be installed in the same axial direction as the existing product.
Further, since the circumferentially bent portion of the split portion shim is housed in the internal fitting groove inside the high-pressure side plate, the split portion shim is not deformed during handling when manufacturing the shaft seal device.

  Furthermore, the shaft seal unit according to the present invention is most suitable for a shaft seal device installed in a fluid seal portion between the outer periphery of the rotating shaft of the turbine rotor and the inner periphery of the stationary blade in a gas turbine or a steam turbine.

According to the present invention, the shaft seal unit includes the axially bent portion formed at the end portion of the high-pressure side plate after the plurality of divided portion shims are inserted into the divided gaps of the circumferentially divided portion of the rotating shaft. Since the dividing gap is laminated to close the dividing gap, the fluid flowing from the high pressure side to the dividing gap is blocked by the flow path block at the axial bending portion of the high pressure side plate end and the axial bending. The flow into the divided gap can be completely blocked by the flow path blocking by the plurality of divided section shims stacked on the section.
Further, according to the present invention, the fluid flowing from the high pressure side to the split gap is blocked in the split gap, and the flow path is blocked at the base portion that closes the split gap of the split shim, and the circumferentially bent portion of the split shim It is possible to completely block the flow into the dividing gap by blocking the flow path by fluid tight contact with the end of the high-pressure side plate.

  Therefore, according to the present invention, it is possible to surely avoid the leakage of the fluid flowing from the high pressure side through the dividing gap to the low pressure side, the nonuniform pressure distribution due to the fluid leakage, and the floating characteristics of the leaf due to this. A shaft seal device for a rotating machine, particularly a turbine rotor in a gas turbine or a steam turbine, which can prevent the occurrence of fluid leakage due to breakage of the leaf accompanying such a decrease in floating characteristics and the failure of the fluid seal at the tip of the leaf. A shaft seal device can be provided that is installed in a fluid seal portion between the outer periphery of the rotating shaft and the inner periphery of the stationary blade or the case member.

  Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in this embodiment are not intended to limit the scope of the present invention only to the description unless otherwise specified. It is just an example.

FIG. 10 is a schematic cross-sectional view along the turbine rotor axial center line showing the structure of the gas turbine to which the present invention is applied.
In FIG. 10, 20 is a compressor, 21 is a combustor, 22 is a turbine, and 7 is a rotating shaft of the compressor 20 and the turbine 22. Reference numeral 24 denotes a turbine casing of the turbine 22, reference numeral 23 denotes a plurality of moving blades of the turbine 22, and reference numeral 24a denotes a plurality of stationary blades.
During the operation of the gas turbine, high-pressure air compressed by the compressor 20 driven by the turbine 22 via the rotating shaft 7 is introduced into the combustor 21, and is converted into the high-pressure air in the combustor 21. The fuel is combusted by being injected, and the combustion gas expands at the stationary blade 24a of the turbine 22 to increase the velocity energy, and acts on the moving blade 23 to rotationally drive the rotary shaft 7. A generator is driven by force.
Reference numeral 100 denotes a shaft seal unit that performs a gas seal between the inner periphery of each stationary blade 24a and the outer periphery of the rotary shaft 7.
The present invention relates to a shaft seal device for a rotary machine applied to the shaft seal unit 100 of the gas turbine.

FIG. 11 is a configuration diagram of the shaft seal unit as viewed in the direction of the rotational axis, and FIG. 12 is an enlarged view of a portion Z in FIG.
11 to 12, reference numeral 100 denotes a shaft seal unit, which is configured as follows.
Reference numeral 1 denotes a leaf made of a thin plate. A large number of the leaves 1 are arranged along the circumferential direction of the rotating shaft 7 (see FIGS. 10 and 13), and each leaf 1 has its outer peripheral portion disposed on the stationary blade 24a (see FIG. 10) and the like, and the inner peripheral portion is fixed as a free end through a back spacer 9 (see FIG. 13). A fluid seal portion is provided between the free end and the outer periphery of the rotary shaft 7. Is forming. The axially opposite sides of the leaf 1, as shown in FIG. 13, the axial fluid flow suppressing high-pressure side plate 2 and the low-pressure side plate 3 passing through the leaf 1, axially sandwiched form the leaf 1 It is installed opposite to.
The shaft seal unit 100 is usually divided into 2 to 8 parts in the circumferential direction for assembly to the outer periphery of the rotary shaft 7 as shown in FIG. Reference numeral 6 denotes a dividing gap formed in the dividing portion.

FIG. 9 shows the assembly structure of the shaft seal unit 100 as viewed in a direction perpendicular to the direction of the rotation axis 7a.
In Figure 9, 5a, 5b in the case member which is divided into two in the axial direction, wherein each leaf 1 is sandwiched as shown in arrow in FIG its outer peripheral portion 1a the case member 5a, at 5b, the back spacer 9 on the outer peripheral side Is inserted and the outer periphery is fixed to the case members 5a and 5b, and the inner periphery is a free end. On both sides in the axial direction of the leaf 1, a high-pressure side plate 2 and a low-pressure side plate 3 that suppress the axial fluid flow passing through the leaf 1 are installed opposite to each other in the axial direction with the leaf 1 interposed therebetween. ing.
The low pressure side plate 3 disposed on the downstream side of the high-pressure side plate 2 and the axial fluid flow is disposed upstream of said axial fluid flow, said leaf as their upper end in FIG arrow The leaf 1 is fixed to the outer periphery by engaging with the groove at the base of the outer periphery.

FIG. 1 is a structural diagram of a divided portion of a shaft seal unit in a gas turbine according to a first embodiment of the present invention, and is a view taken along line YY in FIG. 12, and FIG.
1 and 2, reference numeral 1 is a thin plate, and a large number of leaves are arranged along the circumferential direction of the rotating shaft 7 (see FIGS. 10 and 13). Reference numeral 5 is a case member. The outer peripheral portion 1a of each leaf 1 is sandwiched and fixed by being divided (5a, 5b).
2 is a high-pressure side plate disposed on the upstream side of the leaf 1, and 3 is a low-pressure side plate disposed on the downstream side of the leaf 1. Reference numeral 4 denotes a plurality of divided portion shims inserted into the divided gap 6 shown in FIG.

  In the first embodiment, as shown in FIG. 2, the axially bent portion is formed by bending the end portion of the high-pressure side plate 2 in the direction of the rotation axis 7a (see FIG. 11) of the rotary shaft 7. 2a is formed, and the axially bent portion 2a and the plurality of divided portion shims 4 are stacked and inserted into the divided gap 6 to close the divided gap 6, and the fluid in the divided gap 6 is blocked. The passage is blocked.

  According to the first embodiment, the shaft seal unit 100 is inserted into the divided gap 6 of the circumferentially divided portion of the rotating shaft 7 and a plurality of divided portion shims 4 whose outer peripheral portions 1a are fixed to the case member 5 are inserted. After that, the end portion of the high-pressure side plate 2 is bent in the direction of the rotation axis 7a of the rotary shaft 7 (2s is a bent portion) to form an axial bent portion 2a, and this axial bent portion 2a. Is divided with the dividing portion shim 4 so as to block the dividing gap 6, so that the fluid flowing from the high pressure side toward the dividing gap 6 flows in the axially bent portion 2 a at the end of the high pressure side plate 2. The flow into the divided gap 6 can be completely blocked by the blocking and the flow path blocking by the plurality of divided shims 4 stacked on the axial bent portion 2a.

Therefore, according to this first embodiment, the fluid flowing in Figure 14, as indicated by F arrows, from the high pressure side facing said high-pressure side plate 2 through the split gap 6 into the low pressure side facing the low pressure side plate 3 14 can be surely avoided, and the non-uniform pressure distribution due to the fluid leakage as shown by the range H in FIG.
Thereby, it is possible to avoid the occurrence of fluid leakage due to the breakage of the leaf 1 and the seal failure of the fluid seal portion at the tip of the leaf 1 due to the deterioration of the floating characteristics.
In addition, according to the first embodiment, the other components are replaced with existing components only by changing the shape of the high-pressure side plate 2 by bending the high-pressure side plate 2 to form the axial bent portion 2a. By diverting, the shaft seal unit 100 having the above-described effects can be obtained.

FIG. 3 is a view corresponding to FIG. 1 showing a second embodiment of the present invention, and FIG. 4 is a sectional view taken along line BB of FIG.
In the second embodiment, the shaft seal unit 100 is inserted into the divided gap 6 by inserting a plurality of divided portion shims 4 whose outer peripheral portions are fixed to the case member 5, and the base portion of the divided portion shim 4. 4a closes the dividing gap 6 and bends the dividing portion shim 4 in the circumferential direction (4s is a bending portion) to form a circumferential bending portion 4b. The circumferential bending portion 4b is connected to the high-pressure side. It is configured to be fluid-tightly fixed to the end of the side plate 2.
Other configurations are the same as those of the first embodiment, and the same members are denoted by the same reference numerals.

According to the second embodiment, the dividing gap 6, the split gap 6 by inserting a plurality of divided portions shim 4 which outer peripheral portion is fixed to the case member 5 at the base 4a of the split portion shim 4 After closing, the circumferentially bent portion 4b formed by bending the dividing portion shim 4 in the circumferential direction is brought into fluid tight contact with the end portion of the high-pressure side plate 2, so that the dividing gap 6 is formed from the high-pressure side. The flow path is blocked by the fluid flowing toward the base 4a that blocks the dividing gap 6 of the dividing portion shim 4 and the contact between the circumferential bent portion 4b of the dividing portion shim 4 and the end of the high-pressure side plate 2. Thus, it is possible to completely block the inflow into the dividing gap 6.
Accordingly, it is possible to reliably avoid the leakage of the fluid flowing from the high pressure side through the dividing gap 6 to the low pressure side, thereby reducing the non-uniform pressure distribution due to the fluid leakage and reducing the floating characteristics of the leaf 1 due to this. It is possible to prevent the occurrence of fluid leakage due to the breakage of the leaf 1 and the sealing failure of the fluid seal portion at the tip of the leaf 1 due to the deterioration of the floating characteristics.

Further, according to the second embodiment, in addition to the same effects as those of the first embodiment, the circumferentially bent portion 4b of the dividing portion shim 4 is overlapped with the end portion side surface of the high-pressure side plate 2. Since the structure is in contact, the shaft seal unit having the effects of the first embodiment can be obtained by simply bending the divided portion shim 4 in the circumferential direction and diverting other components to existing components. 100 is obtained.
Further, according to the second embodiment, the dividing portion shim 4 can be deformed even when the leaf 1 is deformed in the circumferential direction, that is, the dividing portion shim 4 is fixed to the case member 5 at the outer peripheral portion. Since the circumferentially bent portion 4a of the dividing portion shim 4 can slide along the high-pressure side plate 2, the high-pressure side integrally including the axially-folded portion 2a as in the first embodiment. The side plate 2 restrains the deformation of the leaf 1 and does not hinder the leaf sealing function.

FIG. 5 is a view corresponding to FIG. 1 showing a third embodiment of the present invention, and FIG. 6 is a sectional view taken along the line CC of FIG.
In the third embodiment, a side fitting groove 2b having a predetermined length is formed along the circumferential direction on the outer surface of the end portion of the high-pressure side plate 2, and the circumferential folding of the dividing portion shim 4 is performed. The portion 4b is superposed on the bottom surface of the side fitting groove 2b in a fluid-tight state so that the circumferentially bent portion 4b fits in the side fitting groove 2b.
Other configurations are the same as those of the first embodiment or the second embodiment, and the same members are denoted by the same reference numerals.

According to the third embodiment, in addition to the same effects as in the first embodiment, the dividing portion shim 4 is bent in the circumferential direction (4s is a bent portion), and the high-pressure side plate 2 The shaft seal unit 100 having the effects of the first embodiment can be obtained by simply carving the side fitting groove 2b at the end and diverting other components to existing components.
Further, according to the third embodiment, the dividing portion shim 4 can be deformed even when the leaf 1 is deformed in the circumferential direction, that is, the dividing portion shim 4 is fixed to the case member 5 at the outer peripheral portion. Therefore, since the circumferentially bent portion 4a of the dividing portion shim 4 can slide along the side fitting groove 2b, the axially bent portion 2a is integrally provided as in the first embodiment. The deformation of the leaf 1 is restrained by the high-pressure side plate 2 and the leaf sealing function is not hindered.
Furthermore, according according to the third embodiment, the since the circumferential bent portion 4b of the divided portions shim 4 are accommodated in the side groove 2b of the high-pressure side plate 2, circumferential fold division part shim 4 There is no increase in the dimension in the axial direction on the high-voltage side from the existing product by superimposing the curved portion 4b on the high-pressure side plate 2, and the dividing portion shim 4 can be installed in the same space as the existing product in the axial direction.

FIG. 7 is a view corresponding to FIG. 1 showing a fourth embodiment of the present invention, and FIG. 8 is a sectional view taken along the line DD of FIG.
In the fourth embodiment, an internal fitting groove 2c having a predetermined length is formed in the end portion of the high-pressure side plate 2 along the circumferential direction, and the circumferentially bent portion 4b of the dividing portion shim 4 is formed. Is inserted into the internal fitting groove 2c and fitted in a fluid-tight state.
Other configurations are the same as those of the first embodiment or the second embodiment, and the same members are denoted by the same reference numerals.

According to this 4th Example, in addition to the effect similar to the said 1st Example, the division part shim 4 is bent in the circumferential direction, and the inside of the edge part of the high voltage | pressure side plate 2 is circumferential. The shaft seal unit 100 having the effects of the first embodiment can be obtained by diving the internal fitting groove 2c having a predetermined length along the line and diverting other components to existing components.
Further, according to the fourth embodiment, the dividing portion shim 4 can be deformed even when the leaf 1 is deformed in the circumferential direction. That is, the dividing portion shim 4 has its outer peripheral portion fixed to the case member 5. Since the circumferential bent portion 4a of the dividing portion shim 4 can slide in the internal fitting groove 2c, the high pressure side integrally including the axial bent portion 2a as in the first embodiment. The side plate 2 restrains the deformation of the leaf 1 and does not hinder the leaf sealing function.

According to the fourth embodiment, since the circumferentially bent portion 4b of the dividing portion shim 4 is housed in the internal fitting groove 2c formed in the high-pressure side plate 2, the dividing portion shim There is no increase in the axial dimension on the high-pressure side from the existing product by overlapping the circumferentially bent portion 4b of 4 on the high-pressure side plate 2, and the dividing portion shim 4 can be installed in the same axial space as the existing product. .
Further, since the circumferentially bent portion 4b of the dividing portion shim 4 is housed in the internal fitting groove 2c inside the high-pressure side plate 2, the dividing portion shim is handled during handling such as carrying when the shaft seal unit 100 is manufactured. 4 is not deformed.

  In addition to the gas turbine, the present invention provides a shaft for a rotary machine, such as a steam turbine, an axial compressor, etc., that seals fluid flowing along the axial direction in the gap between the outer periphery of the rotary shaft and the case member. Applicable to all sealing devices.

  According to the present invention, fluid leakage through the dividing gap formed in the dividing portion of the shaft seal unit is suppressed, and the floating characteristics of the leaf due to such fluid leakage are reduced. It is possible to provide a shaft seal device for a rotary machine that avoids the occurrence of fluid leakage due to poor sealing of the fluid seal portion.

FIG. 13 is a structural diagram of a split portion of the shaft seal unit in the gas turbine according to the first embodiment of the present invention, and is a view on arrow YY in FIG. 12. It is the sectional view on the AA line of FIG. 1 in the said 1st Example. FIG. 3 is a view corresponding to FIG. 1 showing a second embodiment of the present invention. It is the BB sectional drawing of FIG. 3 in the said 2nd Example. FIG. 6 is a view corresponding to FIG. 1 showing a third embodiment of the present invention. It is CC sectional view taken on the line of FIG. 5 in the said 3rd Example. FIG. 6 is a view corresponding to FIG. 1 showing a fourth embodiment of the present invention. It is the DD sectional view taken on the line of FIG. 7 in the said 4th Example. It is the figure seen in the direction orthogonal to the rotating shaft center which shows the assembly structure of the shaft seal unit in the 1st-4th Example of this invention. It is a schematic sectional drawing in alignment with the turbine rotor axial center line which shows the structure of the gas turbine to which this invention is applied. It is a block diagram of the rotating shaft center line direction of the shaft seal unit to which this invention is applied. It is the Z section enlarged view in FIG. It is a principal part perspective view of the shaft seal unit which concerns on a prior art. It is action | operation explanatory drawing of a prior art, and is a YY arrow line view of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Shaft seal mechanism 1 Leaf 2 High pressure side plate 2a Axial bent part 2b Side fitting groove 2c Internal fitting groove 3 Low pressure side plate 4 Dividing part shim 4a Base part 4b Circumferential bending part 2s, 4s Bending part 5 , 5a, 5b Case member 6 Dividing gap 7 Rotating shaft 9 Back spacer

Claims (5)

A shaft sealing device for a rotating machine that seals a fluid flowing along an axial direction between the outer periphery of a rotating shaft of a rotating machine and a case member, and a large number of thin plate leaves along the circumferential direction of the rotating shaft And a fluid seal portion is formed between the free end and the outer periphery of the rotating shaft with the outer peripheral portion of the leaf fixed to the case member and the inner peripheral portion as a free end, and both axial sides of the leaf in the shaft sealing device of a rotary machine of the high-pressure side plate and the low pressure side plate suppressing the axial fluid flow provided with a shaft seal unit consisting installed to face in the axial direction across the leaf through the leaf,
The shaft seal unit inserts a plurality of split portion shims whose outer peripheral portions are fixed to the case member into a split gap formed by splitting in the circumferential direction of the rotating shaft, and only the high-pressure side plate the the end axial bent portion formed by bending in the axial direction of the rotary shaft is inserted into the divided gap, closing the split gap by laminating the above said dividing portion shim axial bent portion A shaft seal device for a rotary machine, comprising: A shaft sealing device for a rotating machine that seals a fluid flowing along an axial direction between the outer periphery of a rotating shaft of a rotating machine and a case member, and includes a plurality of thin leafs along the circumferential direction of the rotating shaft. And a fluid seal portion is formed between the free end and the outer periphery of the rotating shaft with the outer peripheral portion of the leaf fixed to the case member and the inner peripheral portion as a free end, and both axial sides of the leaf In a shaft seal device for a rotary machine comprising a shaft seal unit in which a high-pressure side plate and a low-pressure side plate that suppress axial fluid flow passing through the leaf are installed facing each other in the axial direction across the leaf,
The shaft seal unit is configured by inserting a plurality of divided portion shims whose outer peripheral portions are fixed to the case member into a divided gap formed by dividing the rotating shaft in the circumferential direction of the rotating shaft. The dividing gap is closed and the dividing portion shim is bent in the circumferential direction to form a circumferential bending portion, and the circumferential bending portion is fluidly contacted with an end portion of the high-pressure side plate. And
Further, the shaft sealing device for a rotary machine , wherein the circumferentially bent portion of the divided portion shim is overlapped on the side surface of the end portion of the high-pressure side plate .   A side fitting groove having a predetermined length is formed along the circumferential direction on the outer side surface of the end portion of the high-pressure side plate, and the circumferentially bent portion of the dividing portion shim is formed on the bottom surface of the side fitting groove. The shaft seal device for a rotary machine according to claim 2, wherein the circumferentially bent portions are overlapped so as to be accommodated in the side fitting grooves.   An internal fitting groove having a predetermined length is cut along the circumferential direction inside the end portion of the high-pressure side plate, and the circumferentially bent portion of the divided portion shim is inserted into the internal fitting groove. 3. The shaft seal device for a rotary machine according to claim 2, wherein The rotary machine is either a gas turbine or a steam turbine, and the shaft seal unit is installed in a fluid seal portion between an outer periphery of a rotating shaft of a turbine rotor and an inner periphery of a stationary blade. A shaft seal device for a rotary machine according to any one of claims 1 to 4 .

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