JP2020176680A - Seal device, and turbine - Google Patents

Abstract

To provide a seal device capable of easily suppressing a leakage amount and preventing breakage.SOLUTION: In a seal device 5, a fin 60 protrudes on one of an outer peripheral surface of a rotary body 32 and an inner peripheral surface of a stationary body 50B and a projection 70 protrudes on the other surface. A height H70 of the projection protruding from the other surface is lower than a distance H71 between the other surface and a tip end of the fin in a radial direction. In the fin, a first fin 60d and a second fin 60c are disposed side by side with an inter-fin space S60c interposed therebetween in an axial direction. In the projection, a first projection 70c and a second projection 70c are disposed side by side with an inter-projection space S70b interposed therebetween in the axial direction. The first fin and the first projection are opposed in a radial direction. The second fin and the second projection are not opposed in the radial direction but the second fin and the inter-projection space are opposed in the radial direction.SELECTED DRAWING: Figure 1

Description

Embodiments of the present invention relate to sealing devices and turbines.

Turbines are required to have high efficiency. For high efficiency, for example, a sealing device is installed in the turbine. The sealing device is installed to prevent the hydraulic fluid such as steam from leaking from between the rotating body and the stationary body by sealing between the rotating body and the stationary body.

Patent No. 5518022

A turbine according to a related technique will be illustrated with reference to FIGS. 3 and 4. Here, FIG. 3 is a cross-sectional view of the turbine, and FIG. 4 is an enlarged cross-sectional view of the turbine paragraph in the turbine. In FIGS. 3 and 4, each part is schematically shown with respect to the vertical plane along the rotation axis AX.

In FIGS. 3 and 4, the lateral direction is the axial direction along the rotation axis AX of the turbine rotor 3, the left side is the upstream side Us of the working fluid, and the right side is the downstream side Ds of the working fluid. Further, in FIGS. 3 and 4, the vertical direction is the radial direction of the turbine rotor 3, and in FIG. 4, the upper side is the outer OT and the lower side is the inner IN. In each figure, the dimensional ratio of each part is appropriately changed for convenience of illustration.

As shown in FIG. 3, the turbine 1 has a casing 2 and a turbine rotor 3. The turbine 1 is a multi-stage axial flow turbine, and a plurality of turbine paragraphs are provided inside the casing 2 in the axial direction along the rotation axis AX.

The turbine 1 is, for example, a steam turbine, and steam flows into the inside from the inlet 2a of the casing 2 as a working fluid. Then, the working fluid sequentially flows through a plurality of turbine paragraphs inside the casing 2. That is, the working fluid flows sequentially from the first stage turbine paragraph to the last stage turbine paragraph, and expands and works in each turbine paragraph. As a result, the turbine rotor 3 rotates about the rotation shaft AX inside the casing 2. Then, the working fluid is discharged from the outlet 2b of the casing 2 after flowing out of the turbine paragraph of the final stage.

The details of each part constituting the turbine 1 will be sequentially described below.

Of the turbine 1, the casing 2 has, for example, a double structure and has an inner casing 21 and an outer casing 22, as shown in FIG. Of the casings 2, the inner casing 21 is housed in the internal space of the outer casing 22. The internal casing 21 houses the turbine rotor 3 inside.

In the casing 2, as shown in FIG. 3, a sleeve pipe 23 is installed at the inlet 2a. The sleeve tube 23 is installed so as to penetrate the outer casing 22 and the inner casing 21. Further, the casing 2 houses the nozzle box 24 inside the inner casing 21. The nozzle box 24 is an annular body and is fixed to the inner casing 21 so as to surround the outer peripheral surface of the turbine rotor 3. Further, in the casing 2, the nozzle diaphragm 4 is housed inside the inner casing 21.

As shown in FIGS. 3 and 4, the nozzle diaphragm 4 has a diaphragm inner ring 41, a stationary blade 42, and a diaphragm outer ring 43, and is fixed to the internal space of the inner casing 21. The nozzle diaphragm 4 is arranged around the turbine rotor 3 in the radial direction (radial direction) of the rotating shaft AX. In the nozzle diaphragm 4, a plurality of stationary blades 42 are installed between the inner ring 41 of the diaphragm and the outer ring 43 of the diaphragm. The plurality of stationary blades 42 are arranged along the rotation direction Rt in an annular flow path formed between the diaphragm inner ring 41 and the diaphragm outer ring 43. A plurality of stages of the nozzle diaphragm 4 are installed in the casing 2 corresponding to a plurality of turbine paragraphs. The plurality of stages of nozzle diaphragms 4 are arranged so as to be arranged with a gap in the axial direction along the rotation axis AX. Between the nozzle diaphragms 4 in a plurality of stages, the length (blade length) of the stationary blade 42 extending in the radial direction of the rotation axis AX is sequentially lengthened along the direction in which the working fluid flows.

Among the turbines 1, the turbine rotor 3 is a cylindrical rod-shaped body (shaft), and is configured to be rotated by a working fluid flowing in the axial direction along the rotation shaft AX. In the turbine rotor 3, the rotation shaft AX extends in the horizontal direction and penetrates the casing 2. In the turbine rotor 3, one end portion and the other end portion of the turbine rotor 3 are rotatably supported by bearings 6 outside the casing 2. Although not shown, the turbine rotor 3 has a generator (not shown) connected to one end thereof, and the rotation of the turbine rotor 3 drives the generator to generate electricity.

In the turbine rotor 3, a rotor disk 30 is formed on the outer peripheral surface of a portion housed inside the casing 2. The rotor disc 30 has a ring shape and protrudes outward in the radial direction of the rotating shaft AX, and a plurality of rotor discs 30 are provided at intervals in the axial direction along the rotating shaft AX. A moving blade 31 is fixed to the outer peripheral surface of the rotor disk 30. Although not shown, a plurality of rotor blades 31 are arranged along the rotation direction Rt of the turbine rotor 3. A cover portion 32 (shroud ring) is installed at the tip of the plurality of moving blades 31 arranged in the rotation direction Rt, and the cover portion 32 is connected between the plurality of moving blades 31.

Further, in the row of the plurality of rotor blades 31 arranged in the rotation direction Rt, a plurality of paragraphs (rows) are installed corresponding to the plurality of turbine paragraphs, and the plurality of paragraphs are along the rotation axis AX. They are arranged so as to be lined up with a gap in the axial direction. The moving blades 31 are arranged so that the height (blade length) of the moving blades 31 extending in the radial direction of the rotating shaft AX is sequentially increased along the flow direction of the working fluid.

As shown in FIG. 4, in the turbine paragraph, a sealing device 5 is installed to seal between a rotating body such as a turbine rotor 3 and a stationary body such as a nozzle diaphragm 4 fixed to a casing 2. There is.

As shown in FIG. 4, in the nozzle diaphragm 4, a holder 44 is installed on the inner peripheral surface of the diaphragm inner ring 41. The holder 44 has a ring shape similar to the diaphragm inner ring 41 and the diaphragm outer ring 43.

As shown in FIG. 4, the sealing device 5 includes packing rings 50A and 50B (labyrinth packing). In the turbine paragraph, two types of packing rings 50A and 50B are installed.

Of the two types of packing rings 50A and 50B, one packing ring 50A is fitted to the inner peripheral surface of the holder 44 installed on the inner ring 41 of the diaphragm, and the inner peripheral surface of the packing ring 50A is fitted to the outer peripheral surface of the turbine rotor 3. Are facing each other. The other packing ring 50B is fitted to the inner peripheral surface of the diaphragm outer ring 43, and the inner peripheral surface of the packing ring 50B faces the outer peripheral surface of the cover portion 32.

Although not shown, each of the two types of packing rings 50A and 50B is divided into arcuate segments (not shown) so that each segment (not shown) surrounds the outer peripheral surface of the turbine rotor 3. It is located in.

The details of the sealing device 5 according to the related technique will be described with reference to FIG. FIG. 5 schematically enlarges and shows a portion where the packing ring 50B fitted to the inner peripheral surface of the diaphragm outer ring 43 (stationary body) and the cover portion 32 (rotating body) are provided (FIG. 4). reference).

As shown in FIG. 5, the inner peripheral surface of the packing ring 50B is provided with fins 60 so as to project from the outer OT toward the inner IN in the radial direction. The width of the tip of the fin 60 in the axial direction becomes narrower from the outer OT to the inner IN. Although not shown, the fin 60 is configured to extend along the rotation direction Rt.

There are a plurality of fins 60, and the plurality of fins 60 are arranged in the axial direction. An inter-fin space S60 is interposed between the plurality of fins 60.

Here, the fins 60 include a low fin 601 and a high fin 602 higher than the low fin 601, and the low fins 601 and the high fins 602 are arranged so as to be arranged alternately with each other via the interfin space S60 in the axial direction.

The outer peripheral surface of the cover portion 32 is provided with a convex portion 70 so as to project from the inner IN toward the outer OT in the radial direction. The tip portion of the convex portion 70 has a constant axial width and includes a surface along the axial direction. Although not shown, the convex portion 70 is configured to extend along the rotation direction Rt like the fin 60.

There are a plurality of convex portions 70, and the plurality of convex portions 70 are arranged so as to be arranged in the axial direction. A space S70 (recessed portion) between the convex portions is interposed between the plurality of convex portions 70.

The low fin 601 faces the convex portion 70 in the radial direction. On the other hand, the high fin 602 does not face the convex portion 70 in the radial direction. The high fin 602 faces a portion of the outer peripheral surface of the cover portion 32 where the convex portion 70 is not provided in the radial direction.

With the above configuration, the sealing device 5 has the working fluid flowing in the axial direction along the rotating shaft AX with the cover portion 32 which is a rotating body and the packing ring 50B provided on the diaphragm outer ring 43 which is a stationary body. It suppresses leakage from between.

However, in the case of the above configuration, the high fin 602 may come into contact with the convex portion 70 due to the difference in thermal elongation in the axial direction. In particular, in a low-pressure turbine in which the turbine rotor 3 is long, in a portion largely separated from the bearing (thrust bearing) that rotatably supports the turbine rotor 3, when the turbine is in a transient state (starting, etc.), in the axial direction. Since the difference in thermal expansion is large, the above problems are likely to occur.

In order to prevent the above-mentioned problems from occurring, it is conceivable to increase the distance L between the high fin 602 and the convex portion 70, as shown in FIG.

Also in this case, the leaking fluid LF1 of the working fluid leaked between the high fin 602 and the cover portion 32 flows along the axial direction and then collides with the convex portion 70. Then, the leaking fluid LF1 goes from the inner IN to the outer OT in the radial direction.

As a result, the counter vortex LF2 is generated in the portion located on the outer OT of the convex portion 70 in the radial direction. The counter vortex LF2 goes from the outer OT to the inner IN in the radial direction in the vicinity of the low fin 601. Therefore, the amount of the leaking fluid LF3 leaking from between the low fin 601 and the convex portion 70 can be reduced.

However, as shown in FIG. 6, when the distance L between the high fin 602 and the convex portion 70 is increased, the number of fins 60 and the convex portion 70 that can be installed per unit length in the axial direction is increased. Is reduced. As a result, it may be difficult to sufficiently reduce the amount of leakage.

Due to the above circumstances, it may be difficult for the conventional sealing device to achieve both suppression of the amount of leakage and prevention of damage.

Therefore, an object to be solved by the present invention is to provide a sealing device and a turbine that can easily realize suppression of leakage amount and prevention of damage.

The sealing device of the embodiment includes fins and convex portions, and is arranged around a rotating body that is rotated by a working fluid flowing in an axial direction along a rotating shaft and around the rotating body in the radial direction of the rotating shaft. It is configured to seal between the stationary body and the stationary body. The fins are provided so as to project in the radial direction on one of the outer peripheral surface of the rotating body and the inner peripheral surface of the stationary body. The convex portion is provided so as to project in the radial direction on the other surface of the outer peripheral surface of the rotating body and the inner peripheral surface of the stationary body. The convex portion is wider in the axial direction than the fin, and the height protruding from the other surface is lower than the distance between the other surface in the radial direction and the tip of the fin. The fins include a first fin and a second fin located upstream of the first fin in the axial direction, and the first fin and the second fin pass through the inter-fin space in the axial direction. Lined up. The convex portion includes a first convex portion and a second convex portion located upstream of the first convex portion in the axial direction, and the first convex portion and the second convex portion are in the axial direction. They are lined up through the space between the convex parts. Here, the first fin and the first convex portion face each other in the radial direction. Then, the second fin and the second convex portion do not face each other in the radial direction, but the second fin and the space between the convex portions face each other in the radial direction.

FIG. 1 is an enlarged view showing the sealing device 5 in the turbine according to the embodiment. FIG. 2 is an enlarged view showing the sealing device 5 in the turbine according to the modified example of the embodiment. FIG. 3 is a cross-sectional view of a turbine according to a related technique. FIG. 4 is an enlarged cross-sectional view showing a turbine paragraph in a turbine according to a related technique. FIG. 5 is an enlarged cross-sectional view showing the sealing device 5 in the turbine according to the related technique. FIG. 6 is an enlarged view showing the sealing device 5 in a turbine according to another related technique.

The embodiment will be described with reference to the drawings.

[Constitution]
The details of the sealing device 5 according to the embodiment will be described with reference to FIG. In FIG. 1, as in the case of FIG. 5, a portion where the packing ring 50B fitted to the inner peripheral surface of the diaphragm outer ring 43 and the cover portion 32 is provided is schematically enlarged (FIG. 4). reference).

In the sealing device 5 of the present embodiment, as shown in FIG. 1, the form of the fin 60 and the arrangement relationship between the fin 60 and the convex portion 70 are the same as in the case of the related technology described above (see FIG. 5). It's different. Except for these points and related points, the present embodiment is the same as in the case of the related technology described above. Therefore, the description of overlapping matters will be omitted as appropriate.

In the sealing device 5 of the present embodiment, the fins 60 are provided on the inner peripheral surface of the packing ring 50B so as to project from the outer OT toward the inner IN in the radial direction. Here, a plurality of fins 60 are arranged in the axial direction via the inter-fin space S60. That is, the fins 60a, the fins 60b, the fins 60c, and the fins 60d are sequentially arranged at equal intervals from the upstream side Us to the downstream side Ds. An inter-fin space S60a is interposed between the fins 60a and 60b, an inter-fin space S60b is interposed between the fins 60b and 60c, and an inter-fin space S60c is interposed between the fins 60c and 60d. Is intervening.

In the sealing device 5 of the present embodiment, the convex portion 70 is provided on the outer peripheral surface of the cover portion 32 so as to project from the inner IN to the outer OT in the radial direction. The convex portion 70 has a width in the axial direction wider than that of the fin 60. Here, a plurality of convex portions 70 are arranged in the axial direction via the inter-convex portion space S70. That is, the convex portions 70a, the convex portions 70b, and the convex portions 70c are sequentially arranged at equal intervals from the upstream side Us to the downstream side Ds. An inter-convex space S70a is interposed between the convex portion 70a and the convex portion 70b, and an inter-convex space S70b is interposed between the convex portion 70b and the convex portion 70c. The pitch on which the plurality of convex portions 70 are arranged is wider than the pitch on which the plurality of fins 60 are arranged.

In the present embodiment, each of the plurality of fins 60 (60a, 60b, 60c, 60d) has the same height protruding from the inner peripheral surface of the packing ring 50B, unlike the case of the related technology.

Each of the plurality of convex portions 70 (70a, 70b, 70c) has the same height protruding from the outer peripheral surface of the cover portion 32, as in the case of the related technology. Here, in each of the plurality of convex portions 70, the height H70 protruding from the outer peripheral surface of the cover portion 32 is lower than the distance H71 between the outer peripheral surface of the cover portion 32 and the tip of the fin 60 in the radial direction. (That is, H70 <H71).

Further, in the present embodiment, the fin 60a located on the most upstream side Us among the plurality of fins 60 and the convex portion 70a located on the most upstream side Us among the plurality of convex portions 70 face each other in the radial direction. .. Similarly, the fin 60d located on the most downstream side Ds of the plurality of fins 60 and the convex portion 70a located on the most downstream side Ds of the plurality of convex portions 70 face each other in the radial direction.

On the other hand, the fin 60b located next to the fin 60a on the downstream side Ds of the fin 60a and the fin 60c located next to the fin 60d on the upstream side Us of the fin 60d have a convex portion 70 (70a) in the radial direction. , 70b, 70c) are not facing.

The fins 60b face each other in the radial direction with the inter-convex space S70a interposed between the convex portions 70a and the convex portions 70b. Here, the fins 60b are provided so that their tips face each other in the radial direction with respect to the portion located on the downstream side Ds in the interconvex space S70a.

The fins 60c face each other in the radial direction with respect to the interconvex space S70b interposed between the convex portions 70b and the convex portions 70c. Specifically, the fins 60c are provided so that their tips face each other in the radial direction with respect to the portion located on the upstream side Us in the interconvex space S70b. That is, the axial distance X between the side surface located on the upstream side Us in the interconvex space S70b and the tip of the fin 60c and the axial width W of the interconvex space S70b are the following equations (A). The relationship shown in is satisfied.

0 <X≤W / 2 ... (A)

[Action]
The operation of the sealing device 5 of the present embodiment configured as described above will be described. Here, in the sealing device 5 of the present embodiment, the leaking fluid LF1 leaked into the inter-fin space S60b will be specifically described.

The leaking fluid LF1 leaking into the inter-fin space S60b flows along the axial direction and then flows into the gap located between the fin 60c and the convex portion 70b. As described above, the fins 60c do not face the convex portion 70b in the radial direction, but face the inter-convex space S70b. Therefore, after the leaking fluid LF1 flows into the narrow gap located between the fin 60c and the convex portion 70b, the leaking fluid LF1 bends and flows in a direction inclined with respect to the axial direction so as to go toward the interconvex space S70b. ..

Then, the leaking fluid LF1 collides with the convex portion 70c in the inter-convex space S70b, and then bends and flows toward the inter-fin space S60b. That is, the leaking fluid LF1 goes from the inner IN to the outer OT in the radial direction.

As a result, the counter vortex LF2 is generated in the portion of the inter-fin space S60b located outside the convex portion 70c in the radial direction. The counter vortex LF2 goes from the outer OT to the inner IN in the radial direction in the vicinity of the fin 60d. Therefore, the amount of the leaking fluid LF3 leaking from between the fin 60d and the convex portion 70c can be reduced.

[effect]
As described above, the sealing device 5 of the present embodiment includes fins 60 and convex portions 70. The fins 60 are provided so as to project in the radial direction on the inner peripheral surface of the packing ring 50B. The convex portion 70 is provided so as to project in the radial direction on the outer peripheral surface of the cover portion 32, and the width in the axial direction is wider than that of the fin 60. In the present embodiment, the height H70 of the convex portion 70 protruding from the outer peripheral surface of the cover portion 32 is lower than the distance H71 between the outer peripheral surface of the cover portion 32 and the tip of the fin 60 in the radial direction. Therefore, when the turbine is in a transient state (at the time of starting, etc.), a thermal expansion difference occurs in the axial direction, and the positional relationship between the packing ring 50B which is a stationary body and the cover portion 32 which is a rotating body changes. Even in this case, contact between the fin 60 and the convex portion 70 does not occur. Therefore, in this embodiment, the number of fins 60 and protrusions 70 that can be installed increases per unit length in the axial direction. As a result, in the present embodiment, it is possible to prevent damage and easily reduce the amount of leakage.

Then, in the present embodiment, the fins 60c and the fins 60d are arranged side by side with each other via the inter-fin space S60c in the axial direction. At the same time, the convex portion 70b and the convex portion 70c are arranged side by side with each other via the space between the convex portions S70b in the axial direction. Here, the fin 60d (first fin) and the convex portion 70c (first convex portion) face each other in the radial direction. The fin 60c (second fin) and the convex portion 70b (second convex portion) are provided so as not to face each other in the radial direction but to face the fin 60c and the inter-convex space S70b. Therefore, in the present embodiment, as described above, the counter vortex LF2 is generated in the portion located on the outer OT of the convex portion 70c, so that the leakage amount can be effectively suppressed.

In particular, in the present embodiment, the fins 60c (second fins) are provided so as to face the portion located on the upstream side Us in the interconvex space S70b. As a result, the gap located between the fin 60c and the convex portion 70b becomes narrower. As a result, the leaking fluid LF1 that has flowed into the narrow gap located between the fin 60c and the convex portion 70b tends to bend in a direction inclined with respect to the axial direction so as to go toward the interconvex space S70b. Therefore, in the present embodiment, the counter vortex LF2 is likely to be generated, so that the amount of leakage can be suppressed more effectively.

[Modification example]
In the above embodiment, the case where the fin 60 is provided on the inner peripheral surface of the packing ring 50B which is a stationary body and the convex portion 70 is provided on the outer peripheral surface of the cover portion 32 which is a rotating body has been described. , Not limited to this.

The details of the sealing device 5 according to the modified example of the above embodiment will be described with reference to FIG. In FIG. 2, a portion where the packing ring 50B and the cover portion 32 are provided is schematically enlarged and shown as in the case of FIG. 1 (see FIG. 4).

As shown in FIG. 2, a plurality of fins 60 may be provided on the outer peripheral surface of the cover portion 32 which is a rotating body, and a plurality of convex portions 70 may be provided on the inner peripheral surface of the packing ring 50B which is a stationary body.

In FIG. 2, fins 60a (second fins) and fins 60b (first fins) are sequentially arranged from the upstream side Us to the downstream side Ds, and fins 60a and fins 60b are located between the fins 60a and the fins 60b. An intervening space S60 is present. Then, the convex portion 70a (second convex portion) and the convex portion 70b (first convex portion) are sequentially arranged from the upstream side Us to the downstream side Ds, and the convex portion 70a and the convex portion 70b A space S70 between convex portions is interposed between them.

In this modification, the fins 60a and 60b have the same height protruding from the outer peripheral surface of the cover portion 32.

In this modification, the convex portion 70a and the convex portion 70b have the same height protruding from the inner peripheral surface of the packing ring 50B. Here, the height H70 of the convex portion 70a and the convex portion 70b protruding from the inner peripheral surface of the packing ring 50B is larger than the distance H71 between the inner peripheral surface of the packing ring 50B and the tip of the fin 60 in the radial direction. It is configured to be low (that is, H70 <H71).

In this modification, the fin 60b located on the most downstream side Ds and the convex portion 70b located on the most downstream side Ds face each other in the radial direction.

On the other hand, the fin 60a located on the most upstream side Us and the convex portion 70a located on the most upstream side Us do not face each other in the radial direction. The fins 60a face each other in the radial direction with respect to the interconvex space S70 interposed between the convex portions 70a and the convex portions 70b. Specifically, the fins 60a are provided so that their tips face each other in the radial direction with respect to a portion located on the upstream side Us in the interconvex space S70.

Each of the fins 60a and 60b of this modification is configured in the same manner as the fins 60c and 60d of the above embodiment (see FIG. 1). Each of the convex portion 70a and the convex portion 70b of this modification is configured in the same manner as the convex portion 70b and the convex portion 70c of the above embodiment (see FIG. 1).

Therefore, even in this modified example, the same effect as that of the above-described embodiment can be obtained.

Further, in the above embodiment, the fin 60 or the convex portion 70 is provided on the inner peripheral surface of the packing ring 50B which is a stationary body, and the fin 60 or the convex portion 70 is provided on the outer peripheral surface of the cover portion 32 which is a rotating body. Has been explained, but it is not limited to this.

For example, the fin 60 or the convex portion 70 is provided on the inner peripheral surface of the packing ring 50A fitted to the holder 44 installed on the inner ring 41 of the diaphragm as in the above embodiment, and the outer peripheral surface of the turbine rotor 3 is provided with the above embodiment. The fin 60 or the convex portion 70 may be provided in the same manner as in the above (see FIG. 4). As described above, fins 60 are provided on one of the outer peripheral surface of the rotating body and the inner peripheral surface of the stationary body, and the convex portion 70 is provided on the other surface of the outer peripheral surface of the rotating body and the inner peripheral surface of the stationary body. May be provided.

Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are also included in the scope of the invention described in the claims and the equivalent scope thereof.

1 ... Turbine, 2 ... Casing, 2a ... Inlet, 2b ... Outlet, 3 ... Turbine rotor, 4 ... Nozzle diaphragm, 5 ... Sealing device, 6 ... Bearing, 21 ... Internal casing, 22 ... External casing, 23 ... Sleeve tube, 24 ... Nozzle box, 30 ... Rotor disc, 31 ... Moving wing, 32 ... Cover, 41 ... Diaphragm inner ring, 42 ... Static wing, 43 ... Diaphragm outer ring, 44 ... Holder, 50A ... Packing ring, 50B ... Packing ring, 60 ... Fin, 60a ... Fin, 60b ... Fin, 60c ... Fin, 60d ... Fin, 70 ... Convex, 70a ... Convex, 70b ... Convex, 70c ... Convex, 601 ... Low fin, 602 ... High fin, AX ... Rotation Shaft, Ds ... downstream side, IN ... inside, LF1 ... leaked fluid, LF2 ... counter vortex, LF3 ... leaked fluid, OT ... outside, Rt ... rotation direction, S60 ... interfin space, S60a ... fin space, S60b ... fin Inter-space, S60c ... Inter-fin space, S70 ... Inter-convex space, S70a ... Inter-convex space, S70b ... Inter-convex space, Us ... Upstream side

Claims (3)

A sealing device that seals between a rotating body rotated by a working fluid flowing in an axial direction along a rotating shaft and a stationary body arranged around the rotating body in the radial direction of the rotating shaft.
Fins provided so as to project in the radial direction on one of the outer peripheral surface of the rotating body and the inner peripheral surface of the stationary body.
It is provided so as to project in the radial direction on the other surface of the outer peripheral surface of the rotating body and the inner peripheral surface of the stationary body, the width in the axial direction is wider than that of the fin, and the other surface. With a convex portion whose height protruding from the surface is lower than the distance between the other surface in the radial direction and the tip of the fin.
The fins include a first fin and a second fin located upstream of the first fin in the axial direction, and the first fin and the second fin are in the axial direction. Lined up through the space between the fins in
The convex portion includes a first convex portion and a second convex portion located upstream of the first convex portion in the axial direction, and the first convex portion and the second convex portion. The portions are lined up in the axial direction via the space between the convex portions.
The first fin and the first convex portion face each other in the radial direction.
The second fin and the second convex portion do not face each other in the radial direction, but the second fin and the space between the convex portions face each other in the radial direction.
Sealing device. The second fin is provided so as to face a portion located on the upstream side in the space between the convex portions.
The sealing device according to claim 1. The sealing device according to claim 1 or 2.
Turbine.

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