JP2018159356A - Shaft seal device and rotary machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shaft seal device which inhibits influence on seal characteristics and reduces influences of foreign matters on a seal body.SOLUTION: A shaft seal device 1A is provided between a rotor 102 and a stator 103 enclosing the rotor 102 and partitions a space between the rotor 102 and the stator 103 into a high pressure area S2 and a low pressure area S1 in a center axis direction Da of the rotor 102. The shaft seal device 1A includes: a seal ring comprising multiple seal segments 20A which are provided in a circumferential direction so that circumferential end surfaces 21s are located adjacent to each other; and a thin plate seal 25 fixed to the seal member body 21 and facing the rotor 102. The shaft seal device 1A includes a communication groove 50 which is formed in at least one seal segment 20A, is formed so as to be recessed from the end surface 21s, and allows the high pressure area S2 and the low pressure area S1 to communicate with each other so as to bypass the thin plate seal 25.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a shaft seal device and a rotary machine.

  A rotary machine such as a gas turbine or a steam turbine includes a shaft seal device in order to reduce a leakage amount of a working fluid flowing from the high pressure side to the low pressure side around the rotor. The shaft seal device includes a seal member that partitions a high pressure region and a low pressure region around the rotor.

  In a rotating machine, foreign matter such as scale may enter from the upstream side of the rotating machine. There is a possibility that the foreign matter reaches a seal body provided to face the outer peripheral surface of the rotor in the seal member. The seal body is affected by the arrival of foreign matter in this way, and the seal characteristics may change.

  On the other hand, Patent Document 1 discloses a configuration in which a sealing member is provided with a through hole penetrating in the axial direction of the rotor. The through hole allows the low pressure region and the high pressure region to communicate with each other, and foreign matter can be discharged through the through hole.

Japanese Patent No. 585890

However, the sealing member described in Patent Document 1 needs to form a through-hole so as to bypass the sealing body, which takes time for processing.
Further, the fluid moves from the high pressure region to the low pressure region through the through hole, so that the differential pressure before and after the seal member is reduced. Then, in the circumferential direction outside the rotor in the radial direction, a distribution occurs in the differential pressure between the high pressure region and the low pressure region around the portion where the through hole is provided and the other portion. As a result, the efficiency of the rotating machine may be reduced.
The present invention has been made in view of the above circumstances, and an object thereof is to provide a shaft seal device and a rotary machine that can reduce the influence of foreign matter on a seal body while suppressing the influence on seal characteristics. To do.

The present invention employs the following means in order to solve the above problems.
According to the first aspect of the present invention, the shaft seal device is provided between the rotor and the stator surrounding the rotor, and a space between the rotor and the stator is a high pressure region in the central axis direction of the rotor. And the low pressure area. The shaft seal device includes a seal ring including a plurality of seal ring pieces provided in the circumferential direction so that end faces in the circumferential direction are adjacent to each other, a seal body fixed to each of the seal ring pieces and facing the rotor, Is provided. At least one of the seal ring pieces is formed to be recessed from the end surface, and includes a communication groove that allows the high pressure region and the low pressure region to communicate with each other so as to bypass the seal body.

With this configuration, the foreign matter that has entered the space between the rotor and the stator and has reached the seal body is discharged around the seal body via the communication groove. This suppresses the seal body from being affected by foreign matter.
Such a communication groove is formed on the end surface of the seal ring piece, and is formed on a mating surface with another seal ring piece adjacent in the circumferential direction. In the portion where the end faces of the seal ring pieces are adjacent to each other, the working fluid leaks between the high pressure area and the low pressure area through the gap between the end faces of the adjacent seal ring pieces, so the differential pressure between the high pressure area and the low pressure area Is small. Even if the working fluid leaks through the communication groove provided in the portion where the differential pressure is small in this way, the influence of the leakage of the working fluid through the communication groove is small because the differential pressure is small in the first place.
Furthermore, by forming the communication groove on the end face of the seal ring piece, the processing for forming the communication groove can be easily performed as compared with the case where the through hole is formed in the seal ring piece.

According to the second aspect of the present invention, the shaft seal device according to the first aspect is provided in at least one of the high pressure region and the low pressure region with respect to the seal ring piece, and the outer peripheral surface of the seal body and the rotor A guide member that guides the working fluid to the outside in the radial direction with respect to the gap may be provided.
With this configuration, the working fluid is guided radially outward from the gap between the seal body and the outer peripheral surface of the rotor by the guide member. As a result, the foreign matter is guided radially outward from the gap between the seal body and the outer peripheral surface of the rotor together with the working fluid, and the foreign matter is prevented from entering the gap between the seal body and the outer peripheral surface of the rotor. Therefore, it is suppressed that a foreign material reaches the seal body.

According to the third aspect of the present invention, the guide member according to the second aspect is a blade provided on the outer peripheral surface of the rotor and guiding the working fluid radially outward by rotating integrally with the rotor. It may be.
With this configuration, when the blades provided on the outer peripheral surface of the rotor rotate integrally with the rotor, foreign matters are generated by the flow of the working fluid that is generated by the blades toward the outside in the radial direction. It is guided radially outward from the gap with the surface.

According to the fourth aspect of the present invention, the guide member according to the second aspect may be a wall provided on the outer peripheral surface of the rotor and extending radially outward.
By comprising in this way, it is suppressed by a wall body that a foreign material enters into the clearance gap between a sealing body and the outer peripheral surface of a rotor. Further, the foreign matter is guided radially outward together with the flow of the working fluid that has collided with the wall.

According to the fifth aspect of the present invention, the guide member according to the second aspect may be an umbrella-shaped member provided on the seal ring piece and extending radially inward.
By comprising in this way, it becomes difficult for a foreign material to enter into the clearance gap between a sealing body and the outer peripheral surface of a rotor by an umbrella-shaped guide member.

According to the sixth aspect of the present invention, a plurality of sealing bodies according to any one of the first to fifth aspects may be provided at intervals in the central axis direction. The communication groove may include a branch groove communicating between the seal bodies adjacent to each other in the central axis direction.
By configuring in this way, even if foreign matter enters the gap between the seal body and the outer peripheral surface of the rotor, the foreign matter passes through the communication groove through the branch groove provided between the plurality of seal bodies. , It is discharged around the seal body.

According to a seventh aspect of the present invention, in the shaft sealing device according to the sixth aspect, a gap between the seal body and the outer peripheral surface of the rotor is provided on at least one of the outer peripheral surface of the seal body and the rotor. A guide surface for guiding the working fluid flowing along the direction to the branch groove side may be formed.
With this configuration, the foreign matter that has entered the gap between the seal body and the outer peripheral surface of the rotor is guided to the branch groove side by the guide surface. Thereby, the foreign matter can be more reliably fed into the communication groove through the branch groove.

According to an eighth aspect of the present invention, in the shaft seal device according to any one of the first to seventh aspects, the rotor rotates about the central axis with respect to the communication groove. You may make it provide the circumferential direction guide member which guides the said working fluid to the said communicating groove in the downstream of the flow along the said circumferential direction of the working fluid produced on the radial direction outer side.
By comprising in this way, the foreign material which flows with a working fluid along the circumferential direction is guided to a communicating groove by the circumferential direction guide member. As a result, the foreign matter can be more reliably fed into the communication groove.

According to the ninth aspect of the present invention, the shaft seal device is provided between the rotor and the stator surrounding the rotor, and partitions the high pressure region and the low pressure region in the central axis direction of the rotor. The shaft seal device includes a seal ring including a plurality of seal ring pieces provided in the circumferential direction so that end faces in the circumferential direction are adjacent to each other, a seal body fixed to each of the seal ring pieces and facing the rotor, Is provided. The shaft seal device includes a guide member that is provided at least on the high-pressure region side with respect to the seal ring piece and guides the working fluid radially outward from a gap between the seal body and the outer peripheral surface of the rotor.
With this configuration, the working fluid is guided radially outward from the gap between the seal body and the outer peripheral surface of the rotor by the guide member. As a result, foreign matter that has entered the space between the rotor and the stator is guided radially outward together with the working fluid from the gap between the seal body and the outer circumferential surface of the rotor, and the gap between the seal body and the outer circumferential surface of the rotor. To prevent foreign objects from entering. Therefore, it is suppressed that a foreign material reaches the seal body. This suppresses the seal body from being affected by foreign matter.

According to a tenth aspect of the present invention, a rotary machine includes the shaft seal device according to any one of the first to ninth aspects.
By comprising in this way, a foreign material is bypassed and discharged | emitted by detouring a sealing body via a communicating groove, and it suppresses that a sealing body is influenced by a foreign material. In addition, by forming the communication groove in the part where the end faces of the seal ring pieces with a small differential pressure between the high pressure region and the low pressure region face each other, the influence of the communication groove can be reduced, and the reduction in the operating efficiency of the rotating machine can be suppressed. be able to. Furthermore, the process for forming a communication groove can be easily performed by forming a communication groove in the end surface of a seal ring piece.

  According to the shaft sealing device and the rotating machine, it is possible to suppress the influence on the sealing characteristics and reduce the influence of the foreign matter on the seal body.

It is the figure which looked at the structure of the shaft seal apparatus provided in the rotary machine in one Embodiment of this invention from the center axis direction of the rotor. It is a figure which shows the structure in 1st embodiment of the said shaft seal apparatus, and is XX arrow sectional drawing of FIG. It is a figure which shows the communicating groove formed in the end surface of the seal segment which comprises the said shaft seal apparatus. It is a perspective view of the sealing member main body in which the said communicating groove was formed. It is sectional drawing which shows the structure in 2nd embodiment of the said shaft seal apparatus. It is sectional drawing which shows the structure in the 1st modification of 2nd embodiment of the said shaft seal apparatus. It is sectional drawing which shows the structure in the 2nd modification of 2nd embodiment of the said shaft seal apparatus. It is sectional drawing which shows the structure in 3rd embodiment of the said shaft seal apparatus. It is sectional drawing which shows the structure in the modification of 3rd embodiment of the said shaft seal apparatus. In 4th embodiment of the said shaft seal apparatus, it is the figure which looked at the circumferential direction guide member provided in the opposing part of a fixed seal member and a seal segment from the central-axis direction of the rotor.

Hereinafter, a shaft seal device and a rotary machine according to an embodiment of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a view of the configuration of a shaft seal device provided in a rotary machine according to an embodiment of the present invention, viewed from the direction of the central axis of a rotor. 2 is a cross-sectional view taken along line XX in FIG. FIG. 3 is a view showing a communication groove formed on an end face of a seal segment constituting the shaft seal device. FIG. 4 is a perspective view of the seal member main body in which a communication groove is formed.
As shown in FIGS. 1 and 2, a rotary machine 100 such as a steam turbine or a gas turbine is provided with a stator 103 attached to a passenger compartment (not shown) thereof and an inner side of the stator 103 in the radial direction Dr. And a rotor 102 provided rotatably (not shown).

The shaft seal device 1 </ b> A is provided in an annular space between the rotor 102 and the stator 103.
As shown in FIG. 2, the shaft seal device 1 </ b> A has an annular space formed in the low pressure region S <b> 1 formed on the first side in the central axial direction Da of the rotor 102 and on the second side in the central axial direction Da. And the high pressure region S2.

  As shown in FIG. 1, the shaft seal device 1 </ b> A includes a plurality (eight in this embodiment) of seal segments (seal ring pieces) 20 </ b> A extending in an arc shape. The plurality of seal segments (seal ring pieces) 20A are annularly arranged along the circumferential direction Dc. The shaft seal device 1A constitutes an annular seal ring 5 as a whole by arranging these eight seal segments 20A in the circumferential direction Dc. That is, the seal ring 5 of the shaft seal device 1 </ b> A has a structure that is divided into a plurality of portions in the circumferential direction Dc of the rotor 102.

As shown in FIG. 2, the seal segment 20 </ b> A is held by a housing 104 provided inside the stator 103 in the radial direction Dr. The housing 104 is formed with a groove 105 extending continuously in the circumferential direction Dc around the central axis of the rotor 102.
The groove 105 has an accommodation recess (high-pressure fluid introduction part) 106 and a communication part 107. The accommodating recess 106 is formed in a rectangular cross section. The communication portion 107 communicates the accommodating recess 106 with the inner peripheral surface 104 f of the housing 104. Protruding portions 108 are formed on both sides of the communication portion 107 in the central axis direction Da so as to protrude from the inner wall surface 106a of the housing recess 106 toward the inside of the central axis direction Da. Due to the protrusions 108 and 108, the communication portion 107 has an opening dimension in the central axis direction Da smaller than a width dimension in the central axial direction Da of the housing recess 106.

The seal segment 20 </ b> A includes a seal member main body 21, a thin plate seal (seal body) 25, and a seal fin (seal body) 26.
The seal member body 21 is integrally provided with a pressure receiving portion 22, a base portion 23, and a connecting portion 24.

The pressure receiving portion 22 is housed in the housing recess 106. A pressure receiving surface 22 f is formed outside the pressure receiving portion 22 in the radial direction Dr.
Here, the seal member main body 21 includes notches 35 at a plurality of locations spaced in the circumferential direction Dc. These notches communicate the space 106 s between the pressure receiving surface 22 f and the inner peripheral surface 106 g located outside the radial direction Dr of the housing recess 106 and the high pressure region S <b> 2.

The base portion 23 is disposed on the inner side in the radial direction Dr from the inner peripheral surface 104 f of the housing 104. The width dimension of the base portion 23 in the central axis direction Da is larger than the width dimension of the communication portion 107 in the central axis direction Da.
The connecting part 24 connects the pressure receiving part 22 and the base part 23 through the communication part 107.

  The thin plate seal 25 includes a plurality of metal thin plate seal pieces 27 that are arranged in a multiple manner at a minute interval in the circumferential direction Dc of the rotor 102. In the plurality of thin plate seal pieces 27, the base end portions 27a on the radially outer side are fixed to each other by welding, for example.

The thin plate seal piece 27 is held by a holding member 28 at a base end portion 27 a outside in the radial direction Dr. The holding member 28 includes holding rings 28a and 28b and a connection member 28c. The retaining rings 28a and 28b are formed in a U-shaped cross section. In the connecting member 28c, convex portions 27c and 27d extending on both sides in the central axis direction Da are formed at the base end portion 27a of the thin plate seal piece 27 connecting the holding rings 28a and 28b. The thin plate seal piece 27 is held by the holding member 28 by the convex portions 27 c and 27 d being fitted into the holding rings 28 a and 28 b of the holding member 28. These thin plate sealing pieces 27 are held by the holding member 28 so that the angle formed with the outer peripheral surface of the rotor 102 with respect to the rotation direction of the rotor 102 becomes an acute angle.
Between the base end portion 27 a of the thin plate sealing piece 27 and the holding member 28, a spacer 29 for suppressing rattling of each thin plate sealing piece 27 is provided.

  The thin plate seal 25 and the holding member 28 are accommodated in a concave groove 30 formed in the seal member main body 21. The concave groove 30 includes an outer peripheral groove portion 31 and an inner peripheral groove portion 32. The outer peripheral groove portion 31 is formed at an intermediate portion in the radial direction Dr of the seal member main body 21 and continuously extends in the peripheral direction Dc (see FIG. 1). The inner circumferential groove portion 32 extends from the outer circumferential groove portion 31 toward the inner side in the radial direction Dr, and opens to the inner circumferential surface of the base portion 23 (in other words, the inner circumferential surface 21f of the seal member main body 21). The outer circumferential groove portion 31 is formed to have a larger width dimension in the central axial direction Da than the inner circumferential groove portion 32. The holding member 28 is accommodated in the outer peripheral groove portion 31. The thin plate seal piece 27 has a distal end portion 27 b inside in the radial direction Dr protruding from the base portion 23 through the inner circumferential groove portion 32 inward in the radial direction Dr.

  A leaf spring 33 is provided outside the holding member 28 in the radial direction Dr. The plate spring 33 urges each thin plate seal piece 27 toward the rotor 102 inside in the radial direction Dr.

  In such a thin plate seal 25, when the rotor 102 is stopped, the distal end portion 27b of each thin plate seal piece 27 contacts the rotor 102 with a predetermined preload. When the rotor 102 rotates, the thin plate seal 25 floats from the rotor 102 by the distal end portion 27 b of the thin plate seal piece 27 being displaced radially outward by the dynamic pressure effect generated by the rotation of the rotor 102. As a result, the thin plate seal piece 27 and the rotor 102 are brought into a non-contact state through a slight seal clearance. Thereby, wear of the thin plate seal piece 27 and the rotor 102 is prevented, and leakage of the working fluid (steam) from the high pressure region S2 toward the low pressure region S1 is suppressed.

  The seal fin 26 is provided on the base portion 23 of the seal member main body 21. A plurality of seal fins 26 are provided at intervals in the central axis direction Da of the rotor 102. Each seal fin 26 protrudes from the base portion 23 of the seal member main body 21 toward the inside in the radial direction Dr. A plurality of seal fins 26 are provided on both sides of the central axis direction Da with the thin plate seal 25 interposed therebetween. A labyrinth seal is formed on the high-pressure side and the low-pressure side of the thin plate seal 25 by these seal fins 26.

  During the rated operation, the seal segment 20A has a difference in fluid pressure between the low pressure region S1 and the high pressure region S2 on both sides in the central axis direction Da with respect to the seal segment 20A. As shown in FIG. 2, the high-pressure fluid in the high-pressure region S <b> 2 flows through the notch 35 into the space 106 s between the pressure-receiving surface 22 f and the inner peripheral surface 106 g on the radially outer side of the housing recess 106. Then, as shown in FIG. 1, the back pressure Ph that presses the pressure receiving surface 22f inward from the outside in the radial direction Dr is generated by the high-pressure fluid that has flowed in. With this back pressure Ph, the seal member main body 21 moves to the rotor 102 side. As a result, the clearance is reduced between the thin plate seal 25 and the seal fin 26 and the outer peripheral surface of the rotor 102, and the high pressure region S2 and the low pressure region S1 are partitioned, and a sealing function is exhibited.

  The shaft seal device 1A as described above includes the communication groove 50 in the seal segment 20A. In this embodiment, as shown in FIGS. 3 and 4, for example, the communication groove 50 is formed on the end surface 21s located at the end of the seal member body 21 of the seal segment 20A in the circumferential direction Dc.

  The communication groove 50 is formed in a groove shape extending along the end surface 21s and recessed inward in the circumferential direction Dc from the end surface 21s. One end portion 50a of the communication groove 50 opens toward the low pressure region S1, and the other end portion 50b opens toward the high pressure region S2. The communication groove 50 has one end 50a and the other end 50b extending in the central axis direction Da. The communication groove 50 includes radial flow paths 50c and 50d and an axial flow path 50e between the one end 50a and the other end 50b. The radial flow paths 50c and 50d extend from the one end 50a and the other end 50b toward the outside in the radial direction Dr. The axial flow path 50 e is located outside the radial direction Dr of the thin plate seal 25. The axial flow path 50e extends in the central axial direction Da and connects the outer ends of the radial flow paths 50c and 50d in the radial direction Dr. That is, the communication groove 50 is formed so as to bypass the thin plate seal 25. The communication groove 50 communicates the high pressure region S2 and the low pressure region S1.

  The communication groove 50 exemplified in this embodiment includes a branch groove 51 that communicates between the seal fins 26 and 26 adjacent to each other in the central axis direction Da. The branch groove 51 opens toward the inner side in the radial direction Dr on the inner peripheral surface 21f of the seal member main body 21. The branch groove 51 extends outward in the radial direction Dr, and is connected to one end 50a and the other end 50b of the communication groove 50.

Such a communication groove 50 is formed in the end surface 21s of the seal member main body 21 of the seal segment 20A. In the portion where the end surfaces 21s of the seal segment 20A are adjacent to each other in the circumferential direction Dc, the working fluid leaks from the high pressure region S2 toward the low pressure region S1 through the gap between the adjacent end surfaces 21s. The foreign matter that has entered the space between the stator 103 and the rotor 102 passes through the communication groove 50 together with the leakage flow of the working fluid flowing through the gap between the end faces 21s. In this way, the foreign matter that has entered the space between the rotor 102 and the stator 103 bypasses the thin plate seal 25 via the communication groove 50 and is discharged to the low pressure region S1.
In addition, when foreign matter enters a gap between the inner peripheral surface 21f of the seal member main body 21 and the outer peripheral surface 102f of the rotor 102, the foreign matter passes through the branch grooves 51 and the communication grooves 50 provided between the plurality of seal fins 26. The sheet seal 25 is detoured and discharged.

Therefore, according to the shaft seal device 1 </ b> A and the rotary machine 100 of the first embodiment described above, the foreign matter that has entered the space between the rotor 102 and the stator 103 bypasses the thin plate seal 25 via the communication groove 50. Discharged. This suppresses the thin plate seal 25 from being affected by foreign matter.
Further, since the working fluid leaks between the high pressure region S2 and the low pressure region S1 through the gap between the end surfaces 21s of the seal segment 20A, the high pressure region S2 and the low pressure region S1 are originally formed in the portion where the communication groove 50 is provided. The differential pressure is small. Even if the working fluid leaks through the communication groove 50 provided in the portion where the differential pressure is small in this way, the effect of the leakage of the working fluid in the communication groove 50 is small because the differential pressure is small in the first place.
Further, by forming the communication groove 50 on the end surface 21 s of the seal member main body 21, the processing for forming the communication groove 50 is performed by an end mill, electric discharge machining, or the like as compared with the case where the through hole is formed in the seal member main body 21. Can be easily performed.

  A branch groove 51 communicating with the communication groove 50 is provided between the seal fins 26 adjacent to each other in the central axis direction Da. As a result, even if the foreign matter enters the gap between the inner peripheral surface 21f of the seal member main body 21 and the outer peripheral surface 102f of the rotor 102, the thin plate seal 25 is passed through the branch groove 51 and the communication groove 50. It is possible to discharge foreign substances by detour.

  In this way, the influence on the sealing characteristics of the shaft seal device 1A can be suppressed, and the influence of foreign matter on the thin plate seal 25 can be reduced.

(Second embodiment)
Next, a second embodiment of the shaft seal device and the rotary machine according to the present invention will be described. In the second embodiment described below, in addition to the configuration shown in the first embodiment, only the configuration including the guide member is different, so that FIG. 1 is used and the same reference numerals are used for the same parts as in the first embodiment. Will be described. Further, the description overlapping with the first embodiment is omitted.

  As shown in FIG. 1, the shaft seal device 1B is provided in an annular space between the rotor 102 and the stator 103, similarly to the shaft seal device 1A shown in the first embodiment. The shaft seal device 1B includes a plurality of seal segments (seal ring pieces) 20B.

FIG. 5 is a cross-sectional view showing a configuration in the second embodiment of the shaft seal device.
As shown in FIG. 5, the shaft seal device 1 </ b> B has an annular space formed in the low pressure region S <b> 1 formed on the first side in the central axial direction Da of the rotor 102 and on the second side in the central axial direction Da. And the high pressure region S2.
The seal segment 20 </ b> B includes a seal member main body 21, a thin plate seal 25, and seal fins 26.

The seal segment 20 </ b> B includes a communication groove 50 on the end surface 21 s of the seal member main body 21.
The communication groove 50 is formed in a groove shape extending along the end surface 21s and recessed inward in the circumferential direction Dc from the end surface 21s. One end portion 50a of the communication groove 50 opens toward the low pressure region S1, and the other end portion 50b opens toward the high pressure region S2. The communication groove 50 has radial flow paths 50c and 50d and an axial flow path 50e between the one end 50a and the other end 50b, and is formed so as to bypass the thin plate seal 25. The communication groove 50 communicates the high pressure region S2 and the low pressure region S1.

  The communication groove 50 includes a branch groove 51 communicating between the seal fins 26 and 26 adjacent to each other in the central axis direction Da.

  The seal segment 20B includes a guide member 60 that guides the working fluid to the outside in the radial direction Dr rather than the gap between the inner peripheral surface 21f of the seal member main body 21 and the outer peripheral surface 102f of the rotor 102. In this embodiment, the guide member 60 includes a plurality of wings 61. A plurality of blades 61 are provided on the outer peripheral surface 102f of the rotor 102 at intervals in the circumferential direction Dc. The plurality of blades 61 rotate integrally with the rotor 102 to guide the working fluid to the outside in the radial direction Dr.

  With this configuration, the working fluid is guided by the guide member 60 to the outside in the radial direction Dr rather than the gap between the inner peripheral surface 21f of the seal member main body 21 and the outer peripheral surface 102f of the rotor 102. Accordingly, the foreign matter is guided to the outside in the radial direction Dr together with the working fluid, and is difficult to enter the gap between the inner peripheral surface 21f of the seal member main body 21 and the outer peripheral surface 102f of the rotor 102.

  Therefore, according to the second embodiment described above, the guide member 60 guides the flow Fb of the working fluid to the outside in the radial direction Dr with respect to the gap between the inner peripheral surface 21f of the seal member main body 21 and the outer peripheral surface 102f of the rotor 102. Is done. This prevents foreign matter from entering the gap between the inner peripheral surface 21 f of the seal member main body 21 and the outer peripheral surface 102 f of the rotor 102. Further, the flow of the working fluid Fb is guided to the outside in the radial direction Dr, so that the foreign matter easily flows into the communication groove 50 together with the working fluid. As a result, foreign matter can be prevented from reaching the thin plate seal 25.

Further, as in the first embodiment, the foreign matter that has entered the space between the rotor 102 and the stator 103 is discharged through the communication groove 50 around the thin plate seal 25. Thereby, it can suppress that the thin plate seal | sticker 25 is influenced by a foreign material.
Further, the communication groove 50 is provided in a portion where the working fluid leaks between the high pressure region S2 and the low pressure region S1 through the gap between the end surfaces 21s of the seal segment 20B. Accordingly, even if the working fluid leaks through the communication groove 50, the influence of the communication groove 50 can be reduced.
Furthermore, by forming the communication groove 50 on the end surface 21 s of the seal member main body 21, the processing for forming the communication groove 50 can be easily performed as compared with the case where the through hole is formed in the seal member main body 21. .

  In this way, it is possible to suppress the influence on the sealing characteristics of the shaft seal device 1B and reduce the influence of foreign matter on the thin plate seal 25.

(First modification of the second embodiment)
In the second embodiment, the wing 61 is provided as the guide member 60, but is not limited thereto.
FIG. 6 is a cross-sectional view illustrating a configuration in a first modification of the second embodiment of the shaft seal device.
As shown in FIG. 6, the seal segment (seal ring piece) 20C of the shaft seal device 1C is located on the outer side in the radial direction Dr with respect to the gap between the inner peripheral surface 21f of the seal member main body 21 and the outer peripheral surface 102f of the rotor 102. A guide member 60 for guiding the working fluid is provided. In this embodiment, the guide member 60 is a wall body 62 provided on the outer peripheral surface 102f of the rotor 102 and extending outward in the radial direction Dr.
The wall 62 extends continuously along the circumferential direction Dc. The wall body 62 may be formed at a height extending outward in the radial direction Dr from the gap between the inner peripheral surface 21f of the seal member main body 21 and the outer peripheral surface 102f of the rotor 102.

  With this configuration, when the working fluid hits the wall body 62, the flow Fc changes toward the outside in the radial direction Dr. This prevents foreign matter from entering the gap between the inner peripheral surface 21 f of the seal member main body 21 and the outer peripheral surface 102 f of the rotor 102. Further, since the working fluid flow Fc is guided to the outside in the radial direction Dr, the foreign matter easily flows into the communication groove 50 together with the working fluid. Therefore, it is possible to suppress foreign matters from reaching the thin plate seal 25.

(Second modification of the second embodiment)
FIG. 7 is a cross-sectional view showing a configuration in a second modification of the second embodiment of the shaft seal device.
As shown in FIG. 7, the seal segment (seal ring piece) 20D of the shaft seal device 1D is located on the outer side in the radial direction Dr with respect to the gap between the inner peripheral surface 21f of the seal member main body 21 and the outer peripheral surface 102f of the rotor 102. A guide member 60 for guiding the working fluid is provided.

  In this embodiment, the guide member 60 is an umbrella-like member 63 provided on the seal member main body 21 and extending inward in the radial direction Dr. The umbrella-shaped member 63 is formed in an annular shape extending continuously in the circumferential direction Dc around the central axis of the rotor 102. The umbrella-shaped member 63 is provided inside the radial direction Dr with the central axis of the rotor 102 as the center with respect to the other end portion 50 b of the communication groove 50. The umbrella-shaped member 63 is formed in an umbrella shape in which the outer diameter around the central axis of the rotor 102 gradually decreases as the distance from the side surface of the base portion 23 of the seal member main body 21 toward the central axis direction Da increases. ing. The umbrella member 63 does not contact the outer peripheral surface 102 f of the rotor 102.

  With this configuration, the flow Fd of the working fluid hitting the umbrella-shaped member 63 by the guide member 60 including the umbrella-shaped member 63 causes the inner peripheral surface 21f of the seal member main body 21 and the outer peripheral surface 102f of the rotor 102 to flow. It is guided to the outside in the radial direction Dr rather than the gap. That is, the working fluid flow Fd is guided toward the other end 50 b of the communication groove 50. This makes it difficult for foreign matter to enter the gap between the inner peripheral surface 21 f of the seal member main body 21 and the outer peripheral surface 102 f of the rotor 102. In addition, since the working fluid flow Fd is guided to the outside in the radial direction Dr, foreign matter easily flows into the communication groove 50 together with the working fluid. Therefore, it is possible to suppress foreign matter from reaching the thin plate seal 25.

  In the second embodiment and its modifications, it is possible to adopt a configuration in which the communication groove 50 and the branch groove 51 are not provided.

(Third embodiment)
Next, a third embodiment of the shaft seal device and the rotary machine according to the present invention will be described. In the third embodiment described below, in addition to the configuration shown in the first embodiment, only the configuration including the guide surface is different, so that FIG. 1 is used and the same reference numerals are used for the same parts as in the first embodiment. Will be described. Moreover, the description which overlaps with 1st embodiment is abbreviate | omitted.

  As shown in FIG. 1, the shaft seal device 1 </ b> E is provided in an annular space between the rotor 102 and the stator 103, similarly to the shaft seal device 1 </ b> A of the first embodiment. The shaft seal device 1E includes a plurality of seal segments (seal ring pieces) 20E.

FIG. 8 is a cross-sectional view showing the configuration of the third embodiment of the shaft seal device.
As shown in FIG. 8, the shaft seal device 1E has an annular space formed in the low pressure region S1 formed on the first side in the central axial direction Da of the rotor 102 and on the second side in the central axial direction Da. The high-pressure region S2 is divided.

  The seal segment 20E includes a seal member main body 21, a thin plate seal 25, and seal fins 26.

  The seal segment 20E includes a communication groove 50 on the end surface 21s of the seal member main body 21. The communication groove 50 is formed in a groove shape extending along the end surface 21s and recessed inward in the circumferential direction Dc from the end surface 21s. One end portion 50a of the communication groove 50 opens toward the low pressure region S1, and the other end portion 50b opens toward the high pressure region S2. The communication groove 50 has radial flow paths 50c and 50d and an axial flow path 50e between one end 50a and the other end 50b, and is formed so as to bypass the thin plate seal 25. . The communication groove 50 allows the high pressure region S2 and the low pressure region S1 to communicate with each other.

  The communication groove 50 includes a branch groove 51 communicating between the seal fins 26 and 26 adjacent to each other in the central axis direction Da.

The seal segment 20E includes a guide surface 64. The guide surface 64 is formed facing the upstream side of the flow F of the working fluid in the seal fin 26.
The rotor 102 includes a guide surface 65. The guide surface 65 is formed in an annular recess 66 formed in the outer peripheral surface 102 f of the rotor 102 and recessed inward in the radial direction Dr. The guide surface 65 is formed in the recess 66 so as to face the upstream side of the flow F of the working fluid. In the central axis direction Da, the seal fin 26 disposed in the portion where the recess 66 is formed is formed with such a length that the tip end portion 26a is disposed in the recess 66.

  The flow Fe of the working fluid flowing into the gap between the inner peripheral surface 21f of the seal member main body 21 and the outer peripheral surface 102f of the rotor 102 passes through the gap between the seal fin 26 and the outer peripheral surface 102f of the rotor 102, and then the guide surface 64. Alternatively, when it hits the guide surface 65, it winds up in a spiral shape and is guided radially outward. As a result, the working fluid efficiently flows into the branch groove 51. With this configuration, the foreign matter that has entered the gap between the inner peripheral surface 21 f of the seal member main body 21 and the outer peripheral surface 102 f of the rotor 102 is guided to the branch groove 51 by the guide surfaces 64 and 65. As a result, the foreign matter can be more reliably fed into the communication groove 50 through the branch groove 51.

Therefore, according to the shaft seal device 1E and the rotary machine 100 of the third embodiment described above, the foreign matter that has flowed into the gap between the inner peripheral surface 21f of the seal member main body 21 and the outer peripheral surface 102f of the rotor 102 is guided by the guide surface 64, 65 is guided in a direction toward the outer branching groove 51 in the radial direction Dr. Thereby, the foreign matter can be more reliably fed into the communication groove 50 through the branch groove 51.
As a result, foreign matter can be prevented from reaching the thin plate seal 25 and the thin plate seal 25 can be prevented from being affected.

Similar to the first embodiment, the communication groove 50 is provided in a portion where the working fluid leaks between the high pressure region S2 and the low pressure region S1 through the gap between the end surfaces 21s of the seal segment 20E. Accordingly, even if the working fluid leaks through the communication groove 50, the influence of the communication groove 50 can be reduced.
Furthermore, by forming the communication groove 50 on the end surface 21 s of the seal member main body 21, the processing for forming the communication groove 50 can be easily performed as compared with the case where the through hole is formed in the seal member main body 21. .

  In this way, it is possible to suppress the influence on the sealing characteristics of the shaft seal device 1E and reduce the influence of foreign matter on the thin plate seal 25.

(Modification of the third embodiment)
In the third embodiment, the guide surface 65 is formed in the recess 66 formed in the outer peripheral surface 102f of the rotor 102. However, the present invention is not limited to this.
FIG. 9 is a cross-sectional view showing a configuration of a modification of the third embodiment of the shaft seal device.
As shown in FIG. 9, in the modification of the third embodiment, the seal segment (seal ring piece) 20F of the shaft seal device 1F extends from the inner peripheral surface 21f of the seal member main body 21 to the inside in the radial direction Dr. The seal fins 26 and seal fins (seal bodies) 26F extending from the outer peripheral surface 102f of the rotor 102 to the outside in the radial direction Dr are alternately arranged along the central axis direction Da.

  The seal segment 20F includes a guide surface 64. The guide surface 64 is formed facing the upstream side of the flow F of the working fluid in the seal fin 26. The rotor 102 includes seal fins 26 </ b> F that extend from the outer peripheral surface 102 f of the rotor 102 to the outside in the radial direction Dr. The guide surface 67 is formed facing the upstream side of the flow F of the working fluid in the seal fin 26F.

  The flow Ff of the working fluid that has flowed into the gap between the inner peripheral surface 21f of the seal member main body 21 and the outer peripheral surface 102f of the rotor 102 passes through the gap between the seal fin 26 and the outer peripheral surface 102f of the rotor 102, and then the guide surface 64. Alternatively, when it hits the guide surface 67, it winds up in a spiral shape and is guided outward in the radial direction Dr. As a result, the working fluid efficiently flows into the branch groove 51. With this configuration, the foreign matter that has entered the gap between the inner peripheral surface 21 f of the seal member main body 21 and the outer peripheral surface 102 f of the rotor 102 can be more reliably sent to the communication groove 50 through the branch groove 51.

(Fourth embodiment)
Next, a fourth embodiment of the shaft seal device and the rotary machine according to the present invention will be described. In the fourth embodiment described below, in addition to the configuration shown in the first embodiment, only the configuration including the circumferential guide member is different, so that FIG. 1 is used and the same part as the first embodiment is used. The same reference numerals are used for explanation. Furthermore, the description which overlaps with 1st embodiment is abbreviate | omitted.

  As shown in FIG. 1, the shaft sealing device 1G is provided in an annular space between the rotor 102 and the stator 103, like the shaft sealing device 1A shown in the first embodiment. The shaft seal device 1G includes a plurality of seal segments (seal ring pieces) 20G.

FIG. 10 is a view of the circumferential guide member provided in the facing portion between the fixed seal member and the seal segment as viewed from the central axis direction of the rotor in the fourth embodiment of the shaft seal device.
As shown in FIG. 10, the seal segment 20 </ b> G includes a seal member main body 21, a thin plate seal 25, and seal fins 26.

  The seal segment 20G includes a communication groove 50 on the end surface 21s of the seal member main body 21. The communication groove 50 is formed in a groove shape extending along the end surface 21s and recessed inward in the circumferential direction Dc from the end surface 21s. The communication groove 50 communicates the high pressure region S2 and the low pressure region S1.

  The seal segment 20G includes a circumferential guide member 68. The circumferential guide member 68 is provided on the downstream side of the flow Fg in the circumferential direction Dc of the working fluid generated outside the radial direction Dr of the rotor 102 when the rotor 102 rotates around the central axis with respect to the communication groove 50. Yes. The circumferential guide member 68 is formed on the inner circumferential surface 21f of the seal member main body 21 of the seal segment 20C so as to protrude inward in the radial direction Dr.

  When the rotor 102 rotates, the working fluid on the outer side in the radial direction of the rotor 102 is swung in the same direction as the rotation direction R <b> 1 of the rotor 102 due to the influence of a frictional force generated between the rotor 102 and the outer peripheral surface 102 f of the rotor 102. The flow becomes Fg. The flow Fg of the working fluid along the circumferential direction Dc generated outside the radial direction Dr of the rotor 102 collides with the circumferential guide member 68 and is guided to the communication groove 50 radially outside.

  Therefore, according to the above-described fourth embodiment, the flow Fg of the working fluid in the circumferential direction Dc generated outside the radial direction Dr of the rotor 102 collides with the circumferential direction guide member 68, thereby communicating radially outside. Guided to the groove 50. As a result, the foreign matter can be more reliably fed into the communication groove 50. As a result, the foreign matter is prevented from reaching the thin plate seal 25, and the thin plate seal 25 is prevented from being affected.

Similarly to the first embodiment, the communication groove 50 is provided in a portion where the working fluid leaks between the high pressure region S2 and the low pressure region S1 through the gap between the end surfaces 21s of the seal segment 20G. Accordingly, even if the working fluid leaks through the communication groove 50, the influence of the communication groove 50 can be reduced.
Furthermore, by forming the communication groove 50 on the end surface 21 s of the seal member main body 21, the processing for forming the communication groove 50 can be easily performed as compared with the case where the through hole is formed in the seal member main body 21. .

  In this way, the influence on the sealing characteristics of the shaft seal device 1G can be suppressed, and the influence of foreign matter on the thin plate seal 25 can be reduced.

(Other variations)
The present invention is not limited to the above-described embodiments and modifications, and includes various modifications made to the above-described embodiments without departing from the spirit of the invention. That is, the specific shapes, configurations, and the like given in the embodiment are merely examples, and can be changed as appropriate.
For example, the shaft seal devices 1A to 1G include the thin plate seal 25 and the seal fin 26. However, as long as the seal function can be exhibited between the high pressure region S2 and the low pressure region S1, other seal structures are appropriately used. May be adopted.

In addition, the configurations shown in the above embodiments can be used in appropriate combination.
For example, the blade 61, the wall body 62, and the umbrella-shaped member 63 are formed between the seal fins 26 adjacent to each other in the central axis direction of the rotor 102 or between the seal fins 26 and 26F, and the flow F is formed on the branch groove 51 side. You may make it lead to.

  Furthermore, the shaft seal devices 1A to 1G are not limited to steam turbines and gas turbines, and can be applied to other rotating machines.

1A to 1G Shaft seal device 5 Seal ring 20A to 20G Seal segment (seal ring piece)
21 Seal member body 21f Inner peripheral surface 21s End surface 22 Pressure receiving portion 22f Pressure receiving surface 23 Base portion 24 Connecting portion 25 Thin plate seal (seal body)
26, 26F Seal fin (seal body)
26a distal end 27 thin plate seal piece 27a proximal end 27b distal end 27c, 27d convex 28 holding member 28a, 28b holding ring 28c connecting member 29 spacer 30 concave groove 31 outer peripheral groove 32 inner peripheral groove 33 leaf spring 35 notch 50 communication Groove 50a One end 50b Other end 50c, 50d Radial flow path 50e Axial flow path 51 Branch groove 60 Guide member 61 Wing 62 Wall body 63 Umbrella members 64, 65, 67 Guide surface 66 Recess 68 Circumferential guide member 100 Rotating machine 102 Rotor 102f Outer peripheral surface 103 Stator 103f Inner peripheral surface 105 Groove 106 Housing recess 106a Inner wall surface 106g Inner peripheral surface 106s Space 107 Communication portion 108 Protruding portion Da Central axis direction Dc Circumferential direction Dr Radial direction F Direction Ph Back pressure R1 Rotation Direction R2 Direction S1 Low pressure region S2 High pressure region

Claims (10)

A shaft seal device provided between a rotor and a stator surrounding the rotor, and partitioning a high pressure region and a low pressure region in a central axis direction of the rotor,
A seal ring composed of a plurality of seal ring pieces provided in the circumferential direction so that end faces in the circumferential direction are adjacent to each other;
A seal body fixed to each seal ring piece and facing the rotor,
At least one of the seal ring pieces is formed to be recessed from the end surface, and includes a communication groove that communicates the high pressure region and the low pressure region so as to bypass the seal body.   2. The shaft according to claim 1, further comprising a guide member that is provided at least on the high-pressure region side with respect to the seal ring piece and guides the working fluid radially outward from a gap between the seal body and the outer peripheral surface of the rotor. Sealing device.   The shaft sealing device according to claim 2, wherein the guide member includes a blade that is provided on an outer peripheral surface of the rotor and guides the working fluid to a radially outer side by rotating integrally with the rotor.   The shaft seal device according to claim 2, wherein the guide member is a wall body provided on an outer peripheral surface of the rotor and extending radially outward.   The shaft seal device according to claim 2, wherein the guide member is an umbrella-shaped member provided on the seal ring piece and extending radially inward. A plurality of the sealing bodies are provided at intervals in the central axis direction,
6. The shaft sealing device according to claim 1, wherein the communication groove includes a branch groove that communicates between the seal bodies adjacent to each other in the central axis direction.   A guide surface is formed on at least one of the outer peripheral surfaces of the seal body and the rotor to guide the working fluid flowing along the central axis direction through the gap between the seal body and the outer peripheral surface of the rotor to the branch groove side. The shaft seal device according to claim 6.   With respect to the communication groove, the working fluid is guided to the communication groove on the downstream side of the circumferential flow of the working fluid generated on the radially outer side of the rotor as the rotor rotates around the central axis. The shaft seal device according to any one of claims 1 to 7, further comprising a direction guide member. A shaft seal device provided between a rotor and a stator surrounding the rotor, and partitioning a high pressure region and a low pressure region in a central axis direction of the rotor,
A seal ring composed of a plurality of seal ring pieces provided in the circumferential direction so that end faces in the circumferential direction are adjacent to each other;
A seal body fixed to each of the seal ring pieces and facing the rotor;
A guide member that is provided in at least one of the high-pressure region and the low-pressure region with respect to the seal ring piece, and guides the working fluid radially outward from the gap between the seal body and the outer peripheral surface of the rotor;
A shaft seal device comprising:   A rotary machine comprising the shaft seal device according to any one of claims 1 to 9.

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