WO2012039386A1

WO2012039386A1 - Self-adjusting seal for turbo rotary machine

Info

Publication number: WO2012039386A1
Application number: PCT/JP2011/071352
Authority: WO
Inventors: 西本　慎; 上原　秀和; 中野　隆
Original assignee: 三菱重工業株式会社
Priority date: 2010-09-24
Filing date: 2011-09-20
Publication date: 2012-03-29
Also published as: JP2012067878A; US20120211944A1; DE212011100145U1; CN203730770U

Abstract

A self-adjusting seal (1) includes a movable seal member (20) fitted to a groove (6) of a dummy ring (4) and along a rotor (2). The movable seal member (20) is biased outward in the radial direction by a disc spring (30), and the gap between the movable seal member (20) and the rotor (2) is widened when the turbo rotary machine is activated and stopped. During rated operation of the turbo rotary machine, on the other hand, the movable seal member (20) is pressed to the rotor (2) against the biasing force of the disc spring (30) by a fluid flowing into the groove (6) through between a high-pressure end face of the movable seal member (20) and the groove (6). At least one of a low-pressure end face of the movable seal member (20) and a wall surface of the groove (6) facing the low-pressure end face is treated so as to smoothen the sliding movement relative to each other.

Description

Self-adjusting seal for turbo rotating machinery

The present invention relates to a self-adjusting seal used for a turbo rotating machine such as a steam turbine, a gas turbine, and a compressor. Here, the self-adjusting seal refers to a seal in which the seal gap is automatically adjusted according to the operating state of the turbo rotating machine.

In turbo rotating machines such as steam turbines, gas turbines, and compressors, from the viewpoint of improving operating efficiency, leakage of working fluid through a gap between a rotating member (rotor or moving blade) and a stationary member (chamber or stationary blade) Seals are provided at various locations to prevent this.
For example, a dummy ring seal provided between the high-pressure part and the intermediate-pressure part of a high- and medium-pressure chamber integrated steam turbine, a ground seal provided at a site where the rotor penetrates the vehicle compartment, and between the blade tip and the vehicle compartment Examples thereof include a moving blade tip seal provided, a stationary blade tip seal provided between a stationary blade tip and a rotor.

Conventionally, a labyrinth seal composed of a labyrinth block having a plurality of fins and a leaf spring that elastically supports the labyrinth block from the back surface is generally used for this type of seal. In this case, with the labyrinth block fitted in the groove formed in the stationary member, the labyrinth block is pressed from the back with a leaf spring so that the gap between the fin and the rotating member is maintained constant. Yes. As a result, when the minute gap between the fin and the rotating member passes, the fluid rapidly expands and the pressure decreases, so that fluid leakage is suppressed.

However, in the labyrinth seal configured as described above, if the gap between the fin and the rotating member is too small, depending on the operating state of the turbo rotating machine (especially when starting and stopping), the influence of the difference in thermal expansion between the rotating member and the stationary member In some cases, the fin comes into contact with the rotating member, causing wear of the fin or axial vibration. On the other hand, when the gap between the fin and the rotating member is increased, there is a problem that fluid leakage cannot be sufficiently prevented and the operation efficiency of the turbo rotating machine is lowered.

Therefore, as an alternative to the conventional labyrinth seal, Patent Document 1 describes an automatic adjustment seal in which the seal gap is automatically adjusted according to the operating state of the turbo rotating machine.
This seal includes a fixed seal ring disposed near the horizontal dividing surface of the rotating member (rotor) and a movable seal ring disposed near the center. Among these, the movable seal ring is urged radially outward by an elastic body (a corrugated spring, a disc spring, a metal bellows, etc.), and a sufficient seal clearance is ensured when the turbo rotating machine is started and stopped. It is like that. On the other hand, during the rated operation of the turbo rotating machine, the movable seal ring is pushed radially inward against the urging force of the elastic body by the pressure of the fluid in the turbo rotating machine, so that the seal gap is minimized. can do.

JP 2000-97352 A

Incidentally, the self-adjusting seal described in Patent Document 1 takes into account the frictional force (f) of the sliding portion between the movable seal ring and the stationary member to which the movable seal ring is fixed, and the fluid pressure (P ) Is sufficiently larger than the biasing force (F) by the elastic body.
That is, the shape (effective area) of the movable seal ring and the material and shape of the elastic body are determined so that the following inequality (1) is established at the rated operation of the turbo rotating machine.
Back pressure (P) x effective area of seal ring (A)> biasing force (F) + frictional force (f) (1)

However, in reality, the self-adjusting seal designed by such a method does not always work well, and the seal clearance during the rated operation of the turbo rotating machine becomes excessive, and fluid leakage cannot be prevented sufficiently. It may happen that the movable seal ring operates and contacts the rotating member before passing the critical point during the unsteady operation of the turbo rotating machine. In particular, when the latter situation occurs in ACC abradable seals that have been actively developed in recent years, the abradable material provided on the surface of the movable seal ring is damaged more than expected, and thereafter The seal gap cannot be formed. Note that the ACC abradable seal here is easily cut so that even if the movable seal ring comes into contact with the rotating member for some reason, heat generation that causes bending deformation of the rotating member is suppressed. An automatic adjustment seal with an abradable material provided on the surface of a movable seal ring.
In addition, when a plurality of self-adjusting seals are arranged side by side as dummy ring seals, the timing at which the movable seal ring operates may vary.

Therefore, as a result of examining the factors affecting the operation of the automatic adjustment seal, the present inventors have found that the frictional force (f) of the sliding portion between the movable seal ring and the stationary member varies due to individual differences of the automatic adjustment seal. It was found that the operation of the self-adjusting seal is greatly affected.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an automatically adjusting seal that operates at a desired timing according to the operating state of a turbo rotating machine and can appropriately adjust a seal gap. To do.

An automatic adjustment seal for a turbo rotating machine according to the present invention is an automatic adjustment seal for a turbo rotating machine in which a rotating member rotates while facing a stationary member and transfers energy between the rotating member and a fluid. A movable seal member fitted in a groove provided in the stationary member along the rotary member, and a biasing means for biasing the movable seal member so that a gap between the rotary member and the rotary member is widened. At least during the rated operation of the turbo rotating machine, the movable seal member is urged by the fluid flowing into the groove through the gap between the high-pressure end surface of the movable seal member and the groove. It is configured to be pressed against the urging force against the rotating member side, and at least of the low pressure side end surface of the movable seal member and the wall surface of the groove facing the low pressure side end surface On the other hand, characterized in that the process that facilitates sliding between the wall surface of the low-pressure side end face and the groove of the movable seal member is applied.

In this specification, the “process for smoothing the sliding” refers to an arbitrary process for reducing the friction coefficient in the sliding portion. In addition, although the friction coefficient in a sliding part changes with materials etc. of a movable seal member and a stationary member, when special processing is not performed, it is usually larger than 0.5. Therefore, “the process of smoothing the sliding” can also be referred to as a process of setting the friction coefficient of the sliding part to 0.5 or less, for example, a process of setting the friction coefficient of the sliding part to 0.1 to 0.5. Means.

In the automatic adjustment seal, at least one of the low pressure side end surface of the movable seal member and the wall surface of the groove of the stationary member facing the low pressure side end surface (that is, the sliding portion between the movable seal member and the stationary member) is slid on both. Processing to smooth the movement is applied. For this reason, the “frictional force (f)” in the second term on the right side in the inequality (1) is reduced, and mainly “the back pressure (P) × the effective area of the seal ring (A)” on the left side and the first term on the right side. The operation timing of the self-adjusting seal is determined based on the magnitude relationship of “biasing force (F)”. As a result, the frictional force of the sliding part, which tends to vary due to individual differences in the self-adjusting seal, does not significantly affect the operation of the self-adjusting seal, so the self-adjusting seal at a desired timing according to the operating state of the turbo rotating machine. Can be operated.
In addition, by applying a process for smoothing the sliding of the sliding portion between the movable seal member and the stationary member, the variation in the frictional force of the sliding portion itself is reduced, so that depending on the operating state of the turbo rotating machine The self-adjusting seal can be operated at a desired timing.

In the self-adjusting seal for the turbo rotating machine, as a process for smoothing the sliding, a lubricating film is formed on at least one of the low-pressure side end surface of the movable seal member and the wall surface of the groove facing the low-pressure side end surface May be.

In this case, the lubricating film can be formed, for example, by coating, spraying or plating.

The lubricating coating is made of at least one of molybdenum disulfide, graphite, tungsten disulfide, graphite fluoride, boron nitride, copper, nickel, lead, tin, silver, tetrafluoroethylene, polyimide, and high-density polyethylene. A solid lubricant may be included.

When using a lubricating coating containing a solid lubricant, dimples for fixing the solid lubricant are formed on at least one of the low-pressure side end surface of the movable seal member and the wall surface of the groove facing the low-pressure side end surface. It is preferable.
Thereby, it is possible to prevent the effect of smooth sliding between the movable seal member and the groove wall surface of the stationary member from being lost, and to maintain the normal operation of the automatic adjustment seal for a long period of time.

In the self-adjusting seal for the turbo rotating machine, as a process for smoothing the sliding, a corner portion of the wall surface of the groove facing the low-pressure side end surface of the movable seal member may be chamfered.

Alternatively, in the self-adjusting seal for the turbo rotating machine, as a process for smoothing the sliding, the surface roughness of at least one of the low pressure side end surface of the movable seal member and the wall surface of the groove facing the low pressure side end surface Ra may be 6.3 μm or less.

In the self-adjusting seal for the turbo rotating machine, it is preferable that a film of an abradable material is formed on a surface of the movable seal member facing the rotating member.
As described above, the automatic adjustment seal (so-called ACC abradable seal) in which the abradable material is provided on the surface of the movable seal member is such that the movable seal member contacts the rotary member for some reason during the operation of the turbo rotating machine. However, since the abradable material is easily cut, heat generation can be suppressed, and the bending deformation of the rotating member due to the heat generation can be prevented. Therefore, practical application is strongly desired. However, in the case of the ACC abradable seal, the movable seal member operates faster than the desired timing, and before the turbo rotating machine reaches the rated operation (especially, until it passes the critical point during unsteady operation). When the seal gap becomes narrow and comes into contact with the rotating member, the abradable material is damaged more than expected, and thereafter, a desired seal gap cannot be formed.
In this respect, since the automatic adjustment seal can be operated at a desired timing according to the operating state of the turbo rotating machine, if applied to the ACC abradable seal, damage beyond the abradable material can be prevented. .

According to the present invention, since the sliding portion between the movable seal member and the stationary member has been subjected to a process for smoothing the sliding of the both, the biasing force by the biasing means and the biasing force are mainly resisted. The operation timing of the self-adjusting seal is determined by the relationship with the pressure of the fluid that pushes the movable seal member toward the rotating member. Therefore, the frictional force of the sliding part, which tends to vary due to individual differences in the self-adjusting seal, does not affect the operation of the self-adjusting seal so much. It can be operated.
In addition, by applying a process for smoothing the sliding of the sliding portion between the movable seal member and the stationary member, the variation in the frictional force of the sliding portion itself is reduced, so that depending on the operating state of the turbo rotating machine The self-adjusting seal can be operated at a desired timing.

It is a front view which shows the example of whole structure of an automatic adjustment seal | sticker. It is sectional drawing which shows the structural example of a movable seal member. It is a figure which shows a mode that a movable seal member moves according to the operating state of a turbo rotating machine, (a) is a state of the movable seal member at the time of starting and stopping, (b) is movable at the time of rated operation. The state of the seal member is shown. It is sectional drawing which shows the structural example of the movable seal member in the automatic adjustment seal | sticker of 1st Embodiment. It is sectional drawing which shows the structural example of the movable seal member in the automatic adjustment seal | sticker of 2nd Embodiment. It is sectional drawing which shows the structural example of the movable seal member in the automatic adjustment seal | sticker of 3rd Embodiment. It is sectional drawing which shows the other structural example of a movable seal member.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, and are merely illustrative examples. Only.

[First Embodiment]
FIG. 1 is a front view showing an overall configuration example of an automatic adjustment seal for a turbo rotating machine. As shown in the figure, the automatic adjustment seal 1 is composed of a fixed seal member 10 and a movable seal member 20 provided in an annular shape along the rotor 2 of the turbo rotating machine.

The self-adjusting seal 1 is fitted in a groove formed in a dummy ring 4 (see FIG. 2) attached to a casing (not shown) of the turbo rotating machine, and seals the gap between the rotor 2 and the dummy ring 4. It is like that. Hereinafter, an example in which the automatic adjustment seal 1 is applied to the dummy ring seal provided between the dummy ring 4 as the “stationary member” and the rotor 2 as the “rotating member” of the turbo rotating machine will be described. The self-adjusting seal according to the present invention can be used as a seal for various turbo rotating machines including a gland seal, a stationary blade tip seal, and the like.

In the fixed seal member 10, a pair of upper member 10 </ b> A and lower member 10 </ b> B are disposed on both the left and right sides of the rotor 2, and the upper member 10 </ b> A and lower member 10 </ b> B that make a pair are joined together at a mating surface 12. Seal fins are provided on the inner peripheral side of the fixed seal member 10, and a labyrinth effect is expressed by the seal fins and the concave and convex grooves formed along the circumferential direction of the rotor 2, and the fixed seal member 10 and the rotor The leakage of the fluid between the two (steam when the turbo rotating machine is a steam turbine) is suppressed.
The fixed seal member 10 is elastically supported from the back by a leaf spring or the like, and is configured to be able to escape radially outward when it comes into contact with the rotor 2. It does not move according to the operating state of the rotating machine.

On the other hand, as described below, the movable seal member 20 has a large seal gap with the rotor 2 when the turbo rotating machine is started and stopped, and contacts the fixed seal member 10 at the mating surface 14 during rated operation of the turbo rotating machine. It moves in the direction of the arrow in the figure so as to come into contact, and the seal gap is narrowed.

FIG. 2 is a cross-sectional view illustrating a configuration example of the movable seal member 20. As shown in the figure, the movable seal member 20 is fitted in a groove 6 formed in a dummy ring 4 attached to a passenger compartment (casing).
Seal fins 22 are provided on the inner peripheral side of the movable seal member 20, and the labyrinth effect is expressed by the concave and convex grooves 8 formed along the circumferential direction of the rotor 2 and the seal fins 22. Fluid leakage through the rotor 2 is suppressed.
Further, a disc spring 30 for biasing the upper presser plate 24 of the movable seal member 20 radially outward and a support plate 32 for supporting the disc spring 30 from below are provided in the groove 6 of the dummy ring 4. It has been. Accordingly, the movable seal member 20 is biased by the disc spring 30 so that the gap between the seal fin 22 and the rotor 2 is widened. Instead of the disc spring 30, any biasing means such as a plate spring or a metal bellows may be used.

FIG. 3 is a diagram schematically showing how the movable seal member 20 moves in accordance with the operating state of the turbo rotating machine. FIG. 3A shows the state of the movable seal member 20 when the turbo rotating machine is started and stopped. FIG. 3B shows the state of the movable seal member 20 during the rated operation of the turbo rotating machine.

As shown in FIG. 3A, when the turbo rotating machine is started / stopped, the movable seal member 20 is pushed outward in the radial direction by the biasing force F by the disc spring 30, and the seal fin 22 and the rotor 2 are The gap is widened.
On the other hand, during the rated operation of the turbo rotating machine, as shown in FIG. 3B, there is a difference in the fluid pressure on both sides of the movable seal member 20, and the movable seal member 20 has a thrust force (force caused by the pressure difference). ) in the example shown in the low pressure side (FIG undergoing F ₀ moves to the right) of the movable seal member 20, the low-pressure side end face 26 of the movable seal member 20 is opposed to the groove wall surface (low pressure side end surface 26 of the dummy ring 4 It contacts the wall surface 9) of the groove 6. At this time, the high-pressure side fluid passes between the high-pressure side end face 28 of the movable seal member 20 and the groove 6 of the dummy ring 4 and flows into the internal space 7 of the groove 6. The pressure rises (note that although not shown, several bypass grooves are provided along the circumferential direction of the fixed seal member 20 in FIG. 1 to guide the fluid on the high-pressure side to the internal space 7 of the groove 6. ) As a result, the movable seal member 20 is pressed radially inward by the high-pressure fluid that has flowed into the internal space 7 of the groove 6.

At this time, in order for the movable seal member 20 to actually move inward in the radial direction, it is necessary to satisfy the following inequality.
Back pressure (P) x effective area of seal ring (A)> biasing force (F) + frictional force (f) (1)
Here, the frictional force (f) is obtained by multiplying the friction coefficient μ ₀ at the sliding portion 29 between the low pressure side end face 26 of the movable seal member 20 and the wall surface 9 of the groove 6 by the thrust force F ₀ .

As a result of intensive studies, the inventors have a tendency that the frictional force (f) of the sliding portion 29 tends to vary, and the frictional force (f) at the sliding portion 29 greatly affects the operation of the automatic adjustment seal 1. It came to recognize.

Therefore, in the present embodiment, a lubricating film is provided on at least one of the low pressure side end surface 26 of the movable seal member 20 and the wall surface 9 of the groove 6 facing the low pressure side end surface 26 to facilitate sliding of the sliding portion 29. It has been processed.

FIG. 4 is a cross-sectional view showing a configuration example of the movable seal member 20 in which the sliding portion 29 is provided with a lubricating film. In the example shown in the figure, the lubricating film 40 is provided on both the low pressure side end face 26 of the movable seal member 20 and the wall surface 9 of the groove 6 facing the low pressure side end face 26, but the lubricating film 40 is provided only on one of them. May be provided. The film thickness of the lubricating film 40 is preferably 2 to 7 μm from the viewpoint of sufficiently smoothing the sliding at the sliding portion 29.

As the formation method of the lubricating film 40, it is preferable to select an appropriate method according to the constituent material of the lubricating film 40, and it may be coating, thermal spraying, or plating. For example, the lubricating film 40 may be formed by applying a grease or paste in which a solid lubricant having a powdery or scaly solid having antifriction properties is dispersed.

The solid lubricant used for the lubricating film 40 is at least one of molybdenum disulfide, graphite, tungsten disulfide, graphite fluoride, boron nitride, copper, nickel, lead, tin, silver, tetrafluoroethylene, polyimide, and high-density polyethylene. Preferably it consists of one. Among these, molybdenum disulfide having excellent lubricity and heat resistance can be suitably used as the material for the lubricating film 40.

When the lubricating film 40 includes a solid lubricant, dimples 42 are provided on either the low pressure side end surface 26 of the movable seal member 20 or the wall surface 9 of the groove 6 facing the low pressure side end surface 26 to fix the solid lubricant. It is preferable. FIG. 4 shows an example in which dimples 42 are provided on the wall surface 9 of the groove 6 facing the low-pressure side end surface 26.
Thereby, it is possible to prevent the sliding smoothing effect between the movable seal member 20 and the wall surface of the groove 6 from being lost, and to maintain the normal operation of the automatic adjustment seal 1 over a long period of time.
The dimple 42 may be formed as a recess having a depth of about 10 μm by shot peening, for example.

[Second Embodiment]
Next, the automatic adjustment seal of the second embodiment will be described.
The self-adjusting seal of the present embodiment is a specific aspect of the process of smoothing the sliding at the sliding portion 29 of the wall surface 9 of the groove 6 facing the low pressure side end surface 26 and the low pressure side end surface 26 of the movable seal member 20. Except for this, it is common with the automatic adjustment seal of the first embodiment. Therefore, here, only the sliding smoothing process in the sliding portion 29 will be described.

FIG. 5 is a cross-sectional view showing a configuration example around the low-pressure side end face 26 of the movable seal member 20 in the automatic adjustment seal of the present embodiment. As shown in the figure, as a process for smoothing the sliding of the sliding portion 29, the corner portion 44 of the wall surface 9 of the groove 6 facing the low-pressure side end surface 26 of the movable seal member 20 is chamfered (preferably 1 mm or more). Chamfering). By chamfering the corner portion 44, the corner portion 44 can be prevented from being caught by the low-pressure side end surface 26 of the movable seal member 20, and the sliding portion 29 can be smoothly slid.
The shape of the corner portion 44 after chamfering is not particularly limited. However, as shown in FIG. 5, the corner portion 44 has an R shape (curved shape), so that the corner portion 44 is on the low pressure side of the movable seal member 20. It is possible to reliably prevent the end face 26 from being caught.

[Third Embodiment]
Next, the automatic adjustment seal according to the third embodiment will be described.
The self-adjusting seal of the present embodiment is a specific aspect of the process of smoothing the sliding at the sliding portion 29 of the wall surface 9 of the groove 6 facing the low pressure side end surface 26 and the low pressure side end surface 26 of the movable seal member 20. Except for this, it is common with the automatic adjustment seal of the first embodiment. Therefore, here, only the sliding smoothing process in the sliding portion 29 will be described.

FIG. 6 is a cross-sectional view showing an example of the configuration around the low-pressure side end face 26 of the movable seal member 20 in the automatic adjustment seal of the present embodiment. In this embodiment, the surface roughness Ra of at least one of the low pressure side end face 26 of the movable seal member 20 and the wall surface 9 of the groove 6 facing the low pressure side end face 26 is set to 6.3 μm or less. As a result, the friction coefficient μ ₀ of the sliding portion 29 can be reduced, and the sliding at the sliding portion 29 can be made smooth.

As described above, in the first to third embodiments, the sliding of the movable seal member 20 on at least one of the low-pressure side end surface 26 and the wall surface 9 of the groove 6 facing the low-pressure side end surface 26 is performed. Some sort of processing that smoothes For this reason, the “frictional force (f)” in the second term on the right side in the above inequality (1) is reduced, and mainly “the back pressure (P) × the effective area of the seal ring (A)” on the left side and the first term on the right side. The operation timing of the automatic adjustment seal 1 is determined based on the magnitude relationship of the “urging force (F)”. As a result, the frictional force of the sliding portion 29 that is likely to vary due to individual differences of the automatic adjustment seal 1 does not significantly affect the operation of the automatic adjustment seal 1, so that the desired timing is obtained according to the operating state of the turbo rotating machine. The automatic adjustment seal 1 can be operated.
Further, by applying a process for smoothing the sliding of the sliding portion 29 to at least one of the low-pressure side end surface 26 of the movable seal member 20 and the wall surface 9 of the groove 6 facing the low-pressure side end surface 26. Since the variation of the frictional force itself is also reduced, the automatic adjustment seal 1 can be operated at a desired timing according to the operating state of the turbo rotating machine.

As mentioned above, although embodiment of this invention was described in detail, it cannot be overemphasized that this invention is not limited to this, In the range which does not deviate from the summary of this invention, various improvement and deformation | transformation may be performed.

For example, in the above-described embodiment, the example in which the sliding of the sliding portion 29 is smoothed by a single process has been described. However, the sliding of the sliding portion 29 in the first to third embodiments is facilitated. You may employ | adopt combining a process suitably.

In the above-described embodiment, the fixed seal member 10 and the movable seal member 20 are provided, and seal fins are provided on the inner peripheral sides of the fixed seal member 10 and the movable seal member 20, and the seal fin and the circumferential direction of the rotor 2 are provided. The self-adjusting seal 1 configured to suppress fluid leakage with the concave and convex grooves formed along the groove has been described, but the self-adjusting seal according to the present invention is not limited to this example. For example, the concave and convex grooves may be provided in the fixed seal member 10 and the movable seal member 20, and the seal fin may be provided in the rotating member (rotor 2).
FIG. 7 is a cross-sectional view showing an example in which the concave and convex grooves are provided in the movable seal member 20 and the seal fins are provided in the rotor 2. As shown in the figure, concave and convex grooves 50 are formed along the circumferential direction on the inner peripheral surface of the movable seal member 20 facing the rotor 2, and seal fins 52 are formed along the circumferential direction on the rotor 2. Yes.

As shown in FIG. 7, it is preferable that a coating 54 made of an abradable material is formed on the surface of the movable seal member 20 facing the rotor 2 by thermal spraying.
As a result, even if the movable seal member 20 may come into contact with the rotor 2 for some reason during the operation of the turbo rotating machine, heat generation can be suppressed because the coating 54 is easily cut. The bending deformation of the rotating member can be prevented. On the other hand, the automatic adjustment seal 1 having the above-described configuration can be operated at a desired timing according to the operating state of the turbo rotating machine, and before the turbo rotating machine reaches the rated operation, before the turbo rotating machine reaches the rated operation ( In particular, since the seal gap does not narrow until the critical point at the time of unsteady operation is passed, damage beyond the expected due to contact of the film 54 made of abradable material with the rotor 2 can be prevented.

Claims

A rotating member rotates while facing a stationary member, and is an automatic adjustment seal for a turbo rotating machine that transfers energy between the rotating member and a fluid,
A movable seal member fitted in a groove provided in the stationary member so as to follow the rotating member;
Urging means for urging the movable seal member so that a gap with the rotating member is widened,
At least during rated operation of the turbo rotating machine, the movable seal member is attached to the biasing means by the fluid flowing into the groove through the gap between the high-pressure end surface of the movable seal member and the groove. It is configured to be pressed against the rotating member against the force,
A process for facilitating sliding between the low pressure side end surface of the movable seal member and the wall surface of the groove on at least one of the low pressure side end surface of the movable seal member and the wall surface of the groove facing the low pressure side end surface. Self-adjusting seal for turbo rotating machines, characterized in that
The lubrication film is formed in at least one among the low-pressure side end surface of the said movable seal member and the wall surface of the said groove | channel facing this low-pressure side end surface as a process which makes the said sliding smooth. Self-adjusting seal for turbo rotating machines.
The self-adjusting seal for a turbo rotating machine according to claim 2, wherein the lubricating coating is formed by coating, spraying or plating.
The lubricating coating is a solid lubricant composed of at least one of molybdenum disulfide, graphite, tungsten disulfide, graphite fluoride, boron nitride, copper, nickel, lead, tin, silver, tetrafluoroethylene, polyimide, and high-density polyethylene. The self-adjusting seal for a turbo rotating machine according to claim 2, further comprising an agent.
5. The dimple for fixing the solid lubricant is formed on at least one of the low-pressure side end surface of the movable seal member and the wall surface of the groove facing the low-pressure side end surface. Self-adjusting seal for turbo rotating machines.
The corner portion of the wall surface of the groove facing the low-pressure end surface of the movable seal member is chamfered as the smoothing process. Self-adjusting seal for turbo rotating machines.
As a process for facilitating the sliding, the surface roughness Ra of at least one of the low pressure side end face of the movable seal member and the wall surface of the groove facing the low pressure side end face is set to 6.3 μm or less. The self-adjusting seal for a turbo rotating machine according to any one of claims 1 to 6.
The abradable material film is formed on a surface of the movable seal member facing the rotating member, and the automatic for turbo rotating machines according to any one of claims 1 to 7. Adjustment seal.