JP2011141015A - Sealing device and fluid machine equipped with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sealing device and a fluid machine capable of stably obtaining a vibration suppressing effect. <P>SOLUTION: The sealing device includes a labyrinth seal 10 sealing a radial clearance formed between a rotatably provided rotor 2 and a stator 3 surrounding the rotor 2, and a swirl breaker part 21 extending radially inward from the stator 3 to intercept swirl flow circumferentially flowing through the clearance. The swirl breaker part 21 is provided on the high pressure side rather than the labyrinth seal 10 in an axial direction and is changeable in the angle of attack to the swirl flow. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a sealing device and a fluid machine including the same.

  As is well known, a fluid machine including a rotor provided rotatably and a stator surrounding the rotor includes a seal portion that seals a radial gap formed between the rotor and the stator. There is something. For example, a multi-stage centrifugal compressor is roughly composed of a rotor in which impellers are provided in a plurality of stages in the axial direction and a housing that accommodates the rotor, and an impeller outer peripheral portion and a housing inner peripheral portion in the vicinity of the impeller inlet of each stage. There is one in which a labyrinth seal is provided in a gap in the radial direction between them (for example, see Patent Document 1 below).

  By the way, in the fluid machine as described above, a swirling flow having a circumferential velocity component and flowing along the inner periphery of the stator may occur. When such swirling flow flows into the seal portion, the shaft system The natural frequency is excited and the vibration increases.

  As a means for suppressing vibration due to the swirling flow, a sealing device is known in which a plurality of swirl breakers extending radially inward in the seal portion are provided at intervals in the circumferential direction (for example, the following non-patent document) 1). That is, by blocking the swirling flow flowing in the circumferential direction by the swirl breaker, the swirling flow is decelerated to prevent an increase in vibration.

JP 2008-303767 A

Hideaki Ishimaru, Takuzo Iwasaki “Improved Stability of Grooved Seals and Reduction of Leakage-2nd Report, When a Swirl Breaker is Installed in the Inlet Groove of Parallel Grooved Seal and Spiral Grooved Seal”-The Japan Society of Mechanical Engineers Proceedings of Conference (Volume C) Vol.67, No.661 (2001-9)>

  However, in the prior art, there is a problem in that the vibration suppression effect varies depending on the operation state of the fluid machine, and the vibration suppression effect cannot be obtained stably.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a sealing device and a fluid machine that can stably obtain a vibration suppressing effect.

In order to achieve the above object, the present invention employs the following means.
That is, the sealing device according to the present invention includes a seal portion that seals a radial gap formed between a rotor that is rotatably provided and a stator that surrounds the rotor, and a radially inward portion from the stator. And a swirl breaker that blocks the swirling flow that flows in the circumferential direction through the gap. The swirl breaker is provided on the high pressure side of the seal portion in the axial direction, and the angle of attack with respect to the swirling flow can be changed. It is characterized by being.

  According to this configuration, since the angle of attack of the swirl breaker with respect to the swirl flow can be changed, it is possible to obtain a sufficient vibration suppressing effect by changing the angle of attack of the swirl breaker when the vibration suppressing effect is insufficient. it can. That is, for example, when the operating state changes from a low rotation to a high rotation, the speed and angle of the swirling flow change, so that the angle of attack that can sufficiently decelerate the swirling flow is large. Changes. However, according to the above-described configuration, the swirl breaker can be changed to an appropriate angle of attack, the swirling flow can be sufficiently decelerated, and the shaft vibration can be suppressed. Therefore, the vibration suppressing effect can be stably obtained regardless of the driving situation.

The swirl breaker is provided so as to be rotatable around the extending direction of the swirl breaker.
According to this configuration, since the swirl breaker is provided so as to be rotatable around the extending direction of the swirl breaker, the angle of attack of the swirl breaker can be easily changed with a relatively small amount of operation.

In addition, a sensor unit that measures the flow of the swirl flow and a control unit that controls an angle of attack of the swirl breaker, the control unit based on the measurement value input from the sensor unit. The angle of attack is controlled so that the swirl breaker intersects the first and second swirl breakers.
According to this configuration, since the control unit controls the angle of attack so that the swirl breaker intersects the swirl flow, the swirl flow is automatically and continuously adjusted by automatically adjusting the angle of attack of the swirl breaker. It can be decelerated.

A storage unit that stores an inclination angle formed by the swirl breaker with respect to an axial direction and that minimizes the speed of the swirling flow for each of the different rotation speeds of the rotor; and the reception of the swirl breaker A control unit that controls an angle, and the control unit controls the angle of attack so that the tilt angle becomes an optimum tilt angle according to the number of rotations of the rotor.
According to this configuration, the angle of attack is controlled so that the tilt angle of the swirl breaker becomes the optimum tilt angle according to the rotational speed of the rotor, so that the turning that follows the circumferential direction in proportion to the rotational speed of the rotor Using the nature of the flow, the swirl flow can be automatically and continuously decelerated by automatically adjusting the angle of attack of the swirl breaker.

Furthermore, the fluid machine according to the present invention includes any one of the above-described sealing devices.
According to this configuration, since any one of the above-described sealing devices is provided, a fluid machine in which vibration is stably suppressed can be obtained.

According to the sealing device of the present invention, it is possible to stably obtain a vibration suppressing effect.
Moreover, according to the fluid machine which concerns on this invention, the fluid machine by which the vibration was suppressed stably can be obtained.

It is a schematic structure sectional view of seal device 1 concerning a first embodiment of the present invention. It is a schematic block diagram of the sealing device 1 which concerns on 1st embodiment of this invention, Comprising: It is I arrow directional view in FIG. It is a schematic structure sectional view of seal device 1 concerning a first embodiment of the present invention, and is a sectional view taken along line II-II. FIG. 2 is a development view of the sealing device 1 according to the first embodiment of the present invention, and is a development view developed in the circumferential direction with one wing member 20 as a reference. It is a schematic block diagram of the sealing device 1 which concerns on 1st embodiment of this invention, Comprising: It is the III arrow directional view in FIG. It is a schematic block diagram of the sealing apparatus 1 which concerns on 1st embodiment of this invention, Comprising: It is the IV arrow directional view in FIG. It is a schematic block diagram of the sealing device 1 which concerns on 1st embodiment of this invention, Comprising: It is the III arrow directional view in FIG. 1 which showed the state different from FIG. It is a schematic block diagram of the sealing device 1 which concerns on 1st embodiment of this invention, Comprising: It is the IV arrow directional view in FIG. 1 which showed the state different from FIG. It is a schematic block diagram of the sealing apparatus 101 which concerns on 2nd embodiment of this invention, Comprising: It is a figure equivalent to FIG. It is a graph for demonstrating the control conditions of the sealing apparatus 101 which concerns on 2nd embodiment of this invention. It is a schematic block diagram of the centrifugal compressor 204 to which the sealing apparatus which concerns on embodiment of this invention is applied.

(First embodiment)
Embodiments of the present invention will be described below with reference to the drawings.
1 is a schematic cross-sectional view of a sealing device 1 according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along arrow I in FIG. 1, and FIG. 3 is a cross-sectional view taken along line II-II.
As shown in FIG. 1, the sealing device 1 is used in a fluid machine 4 that includes a rotor 2 that is rotatably provided and a cylindrical housing (stator) 3 that surrounds the rotor 2. As shown in FIG. 1, the sealing device 1 is schematically configured from a labyrinth seal (seal part) 10, a plurality of wing members 20, and a movable mechanism 30.

  As shown in FIG. 1, the labyrinth seal 10 includes a plurality of annular fins 11 extending radially inward from the peripheral wall 3 a of the housing 3 in the axial direction. The gap S in the radial direction formed therebetween is sealed to prevent fluid from leaking from the high pressure side to the low pressure side (left side to right side in FIG. 1).

  As shown in FIG. 1, the wing member 20 includes a swirl breaker portion (swirl breaker) 21 located in the gap S and a mounting shaft portion 22 attached to the housing 3.

  As shown in FIGS. 1 to 3, the swirl breaker portion 21 is formed in a plate shape, and extends radially inward from the mounting shaft portion 22.

  As shown in FIGS. 1 and 3, the mounting shaft portion 22 is formed in a step shape with two different outer diameters, and rotates on a bearing member 3 b (described later) fixed to the peripheral wall 3 a of the housing 3. It is possible to fit.

  A plurality of such blade members 20 are paired with the bearing member 3b and are disposed at positions adjacent to the labyrinth seal 10 on the high-pressure side in the axial direction as shown in FIG. 1, as shown in FIG. In addition, they are annularly arranged at equal intervals.

As shown in FIGS. 1 and 3, the bearing member 3b is a member including a bearing body 3b1 formed in a substantially cylindrical shape and a locking wall 3b2 projecting in a normal direction from one end surface of the bearing body 3b1. (See FIG. 5), the shaft hole 3b3 penetrates the bearing body 3b1 and the locking wall 3b2.
The bearing member 3b is airtightly fixed in a state of penetrating the peripheral wall 3a, and the locking wall 3b2 is positioned outside the housing 3, and the locking wall 3b2 is directed in a tangential direction of the peripheral wall 3a ( (See FIG. 5).
Note that the blade member 20 is restrained from being displaced except in the radial direction, which is the extending direction of the swirl breaker portion 21, because the mounting shaft portion 22 formed in a step shape interferes with the bearing member 3 b.

FIG. 4 is a development view developed in the circumferential direction with one wing member 20 as a reference.
As shown in FIGS. 1 and 3, the swirl breaker portion 21 has a radial direction that is an extending direction as shown in FIG. 4 by fitting the mounting shaft portion 22 rotatably to the bearing member 3 b. It can be rotated around a predetermined range. More specifically, the inclination angle α formed by the reference center line P passing through the center of the member thickness of the swirl breaker portion 21 with respect to the axial direction is rotatable within a predetermined range.

As shown in FIGS. 1 and 2, the movable mechanism 30 includes an outer ring member 31, a gripping member 32, and a plurality of connecting members 33.
As shown in FIG. 2, the outer ring member 31 has an outer diameter larger than the outer diameter of the peripheral wall 3 a of the housing 3, and surrounds the peripheral wall 3 a of the housing 3 with a space therebetween. The outer ring member 31 is supported by the peripheral wall 3a via the connecting member 33, the wing member 20, and the bearing member 3b.
As shown in FIG. 2, the gripping member 32 is a long member, is bolted to the lower side of the outer ring member 31, and is suspended from the outer ring member 31.

5 is a view taken in the direction of arrow III in FIG. 1, and FIG. 6 is a view taken in the direction of arrow IV in FIG.
As shown in FIG. 5, each connecting member 33 is a book-like member and is paired with the wing member 20. Each connecting member 33 connects the mounting shaft portion 22 of the paired wing member 20 and the outer peripheral surface of the outer ring member 31.

More specifically, as shown in FIG. 5, each connecting member 33 is connected to the mounting shaft portion 22 of the paired wing member 20 via a bolt 34 a and is connected to the mounting shaft portion 22. The relative displacement is restricted.
Further, as shown in FIG. 5, each connecting member 33 is connected to the outer ring member 31 via a bolt 34 b, and relative displacement in the circumferential direction is restricted with respect to the outer ring member 31, and the radial direction Relative rotation is allowed around.

As shown in FIGS. 5 and 6, each connecting member 33 is connected to the wing member 20 so that the reference center line P of the swirl breaker portion 21 of the paired wing member 20 faces the longitudinal direction of the connecting member 33. Has been.
As shown in FIGS. 5 and 6, each connecting member 33 overlaps the reference center line P of the swirl breaker portion 21 with the longitudinal direction of the connecting member 33. As shown in FIGS. 1 and 2, each connecting member 33 is set so that the longitudinal direction thereof is oriented in the axial direction together with the reference center line P of the swirl breaker portion 21 at the initial position where the gripping member 32 is located at the lowest position. Has been. In this state, a gap G is formed between the locking wall 3b2 of the bearing member 3b and the outer ring member 31, as shown in FIG.

7 is a view taken along arrow III in FIG. 1 when the movable mechanism 30 is operated, and FIG. 8 is a view taken along arrow IV in FIG. 1 when the movable mechanism 30 is operated.
In the movable mechanism 30 as described above, when the outer ring member 31 rotates in the circumferential direction, the connecting members 33 are driven by the outer ring member 31.
That is, when the outer ring member 31 receives a force in the circumferential direction, the connecting member 33 receives a force in the circumferential direction. As described above, relative displacement of the connecting member 33 in the circumferential direction with respect to the outer ring member 31 is restricted, and relative rotation around the radial direction is allowed. Further, relative displacement is restricted with respect to the mounting shaft portion 22 that can be rotated around the radial direction. For this reason, as shown in FIGS. 4 and 6, the connecting member 33 has the mounting shaft portion 22 of the wing member 20 as the rotation center, and the tangential direction (or circumferential direction) from the state in which the longitudinal direction is directed in the axial direction. Rotate to tilt. By this rotation, the swirl breaker portion 21 of the wing member 20 is moved from the state in which the reference center line P is directed in the longitudinal direction (inclination angle α = 0 °) as shown in FIG. It is rotated so as to be inclined in the tangential direction (or circumferential direction) (inclination angle α> 0 ° or inclination angle α <0 °).

At this time, when the gap G between the locking wall 3b2 of the bearing member 3b and the outer ring member 31 is reduced and the locking wall 3b2 and the outer ring member 31 come into contact with each other as shown in FIG. = 0) The inclination angle α is maximized, and the rotation of the swirl breaker portion 21 is restricted to a predetermined range.
In this way, the movable mechanism 30 changes the inclination angle α of the swirl breaker portion 21 with respect to the axial direction by synchronizing the wing members 20.
A fixing pin or the like may be used in order to more securely fix the set inclination angle α.

Next, the operation of the sealing device 1 will be described. In the following description, a case where the operation of the fluid machine 4 is changed from the high output mode (high rotation state) to the low output mode (low rotation state) will be described.
First, due to the rotation of the rotor 2, a shearing force acts on the fluid around the rotor 2 in the rotational tangential direction from the rotor 2. Due to the action of the shearing force, a swirling flow C having a circumferential velocity component is generated (hereinafter, the swirling flow C in the high output mode is referred to as “swirling flow C1”).

  When the operation of the fluid machine 4 is in the high output mode, since the rotor 2 is rotating at high speed, the shear force acting on the fluid is relatively large, and the axial velocity component of the swirling flow C1. However, the ratio of the velocity component in the tangential direction is large. For this reason, the direction of the swirling flow C1 is along the circumferential direction as shown in FIG.

At this time, as shown in FIG. 4, the swirl breaker portion 21 of the wing member 20 has the reference center line P directed in the axial direction, so that the angle of attack β1, which is a relative angle with respect to the swirl flow C1, becomes a substantially right angle. The swirl flow C1 collides with the swirl breaker portion 21 so as to be orthogonal. For this reason, the velocity component in the tangential direction of the swirling flow C1 is sufficiently decelerated.
Even if the fluid in which the velocity component in the tangential direction is sufficiently decelerated flows into the labyrinth seal 10, the natural frequency of the rotor 2 is not excited, and the rotor 2 rotates stably without vibration.

  On the other hand, when the operation of the fluid machine 4 is set to the low output mode, the rotor 2 is rotated at a low speed, so that the shearing force acting on the fluid around the rotor 2 is relatively small. In this case, the ratio of the tangential velocity component to the axial velocity component of the swirling flow C is smaller than that in the high output mode (hereinafter, the swirling flow C in the low output mode is referred to as “swirl flow C2”). And). Therefore, the swirl flow C2 is inclined in the axial direction as shown in FIG.

  At this time, as shown in FIG. 4, the swirl breaker portion 21 of the wing member 20 has the reference center line P directed in the axial direction, so that the angle of attack β2 with respect to the swirling flow C2 becomes an acute angle, and the swirl breaker portion 21 On the other hand, the swirl flow C2 collides obliquely. For this reason, the velocity component in the tangential direction of the swirl flow C2 that has collided with the swirl breaker portion 21 cannot be sufficiently decelerated, and the swirl flow C2 flows along the swirl breaker portion 21 to the labyrinth seal 10. Inflow. For this reason, the velocity component in the tangential direction is not sufficiently decelerated, and the swirling flow C2 flows into the labyrinth seal 10, and the natural frequency of the rotor 2 may be excited and the rotor 2 may be unstablely vibrated.

  Therefore, by changing the inclination angle α of the swirl breaker portion 21 with respect to the axial direction, the angle of attack β, which is the relative angle of the swirl breaker portion 21 with respect to the swirl flow C2, is set to an angle at which the swirl flow C2 can be sufficiently decelerated. adjust. Specifically, as described above, the movable mechanism 30 is operated to rotate the swirl breaker portion 21 around the extending direction so that the angle of attack β2 becomes a substantially right angle of attack β2 ′.

  When the swirl breaker portion 21 reaches the angle of attack β2 ′, the swirl flow C2 collides so as to be orthogonal to the swirl breaker portion 21, so that the velocity component in the tangential direction of the swirl flow C2 is sufficiently decelerated. As described above, even if the fluid in which the velocity component in the tangential direction is sufficiently decelerated flows into the labyrinth seal 10, the natural frequency of the rotor 2 is not excited, so that the rotor 2 is stably in a state without vibration. Rotate.

  As described above, in the sealing device 1 of the present embodiment, the angle of attack β of the swirl breaker portion 21 with respect to the swirl flow C (C1, C2) can be changed, so that the swirl is insufficient when the vibration suppressing effect is insufficient. A sufficient vibration suppressing effect can be obtained by changing the angle of attack β of the breaker unit 21. That is, for example, when the rotor 2 rotates from a low rotation to a high rotation and the operating state changes, the speed and angle of the swirling flow C change, and therefore the angle of attack that can sufficiently decelerate the swirling flow C. The magnitude of β changes. However, according to the above-described configuration, the swirl breaker portion 21 can be changed to an appropriate angle of attack β, and the swirling flow C can be sufficiently decelerated, and axial vibration can be suppressed. Therefore, the vibration suppressing effect can be stably obtained regardless of the driving situation.

  Further, since the swirl breaker portion 21 is provided so as to be rotatable around the extending direction of the swirl breaker portion 21, the angle of attack β of the swirl breaker portion 21 can be easily changed with relatively little operation. .

  Further, by adjusting the angle of attack β (β1, β2) so that the swirl breaker portion 21 is orthogonal to the swirl flow C, the velocity component in the tangential direction of the swirl flow C can be sufficiently decelerated. A vibration suppressing effect can be obtained.

  Moreover, in the fluid machine 4 of this embodiment, since the sealing device 1 is provided, vibrations can be stably suppressed in a wide rotation range of the rotor 2.

(Second embodiment)
FIG. 9 is a schematic configuration diagram of the sealing device 101 according to the second embodiment of the present invention, and corresponds to FIG. 2 of the first embodiment described above. In FIG. 9, the same components as those in FIGS. 1 to 8 are denoted by the same reference numerals, and the description thereof is omitted.

  Whereas the sealing device 1 according to the first embodiment described above is configured to manually rotate the outer ring member 31 and the swirl breaker portion 21, the sealing device 101 of the present embodiment includes the outer ring member 31 and The swirl breaker unit 21 is automatically rotated.

  As shown in FIG. 9, the sealing device 101 includes an outer ring member 131, a gear mechanism 110, and a control device 120.

The outer ring member 131 has substantially the same configuration as the outer ring member 31, but differs from the outer ring member 31 in that an outer tooth 31 a is formed on a part of the outer peripheral portion.
The gear mechanism 110 includes a gear 111 that meshes with the external teeth 31a and is rotated by external power.
The control device 120 includes a storage unit 121 and a control unit 122.

FIG. 10 is a graph showing the relationship between the turning flow velocity V and the inclination angle α, where the thin line is a graph at a relatively low rotational speed N1, and the thick line is a graph at a relatively high rotational speed N2. .
The storage unit 121 stores an inclination angle α of the swirl breaker unit 21 at which the swirl flow velocity of the swirl flow C is minimized for each predetermined number of rotations of the rotor 2. That is, when the rotational speed of the rotor 2 changes, the turning direction of the swirling flow C changes, so that the optimum inclination angle α _j of the swirl breaker portion 21 that can minimize the flow velocity of the swirling flow C changes. For example, when the rotational speed N1 is a relatively low rotational speed, the optimum inclination angle α _j is small (inclination angle α1), and when the rotational speed N2 is a relatively high rotational speed, the optimal inclination angle is set. The angle α _j increases (inclination angle α2 (> α1)).
The storage unit 121 stores the optimum inclination angle α _j for each predetermined rotation speed N1... N2 of the rotor 2.

The controller 122 receives the detected rotation speed of the rotor 2 and outputs a drive control signal to the gear mechanism 110. More specifically, the gear mechanism is configured so that the optimum inclination angle α _j is obtained by referring to the storage unit 121 based on the input rotational speed of the rotor 2 and the swirl breaker part 21 has the optimum inclination angle α _j. 110 is driven and controlled.

As described above, according to the sealing device 101 according to the present embodiment, the angle of attack β is controlled so that the inclination angle α of the swirl breaker portion 21 becomes the optimum inclination angle α _j according to the rotational speed of the rotor 2. To do. That is, since the rotational speed of the rotor 2 and the swirl direction of the swirl flow C are correlated, the swirl flow is changed by changing the inclination angle α of the swirl breaker portion 21 with respect to the axial direction based on the revolving speed of the rotor 2. It is possible to feed-forward control the angle of attack β of the swirl breaker unit 21 with respect to C to an optimum value. The swirl flow C is automatically adjusted by automatically adjusting the angle of attack β of the swirl breaker portion 21 by utilizing the property of the swirl flow C that extends along the circumferential direction in proportion to the rotational speed of the rotor 2. In addition, the vehicle can be sufficiently decelerated continuously.

  Also, according to the sealing device 101, the angle of attack β is controlled so that the swirl breaker portion 21 is orthogonal to the swirl flow C. Therefore, the angle of attack β of the swirl breaker portion 21 is automatically adjusted to rotate the swirl flow C Can be slowed down more automatically and continuously.

  In the present embodiment, the swirl breaker unit 21 is feedforward controlled. However, for example, a fluid sensor is provided in the gap S to detect the direction of the swirling flow, and is orthogonal to the detected direction of the swirling flow. Even if the angle of attack β of the swirl breaker 21 is changed, the swirl flow C can be decelerated automatically and continuously more sufficiently. Even with such feedback control, it is possible to continuously obtain the vibration suppressing effect.

  In this embodiment, the movable mechanism 30 includes the outer ring member 31, the gripping member 32, and the connecting member 33, and the wing member 20 is rotated by the gear mechanism 110, but the wing member 20 is simply driven. A wing member 20 may be rotated by providing a motor.

Note that the operation procedure shown in the above-described embodiment, various shapes and combinations of the constituent members, and the like are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.
For example, in the embodiment described above, the swirl breaker portion 21 is formed in a plate shape, but other shapes may be used, for example, a streamline type may be used.

For example, in the above-described embodiment, the sealing device 1 or 101 according to the present invention is applied to the fluid machine 4, but the present invention can be suitably applied to a centrifugal compressor.
For example, as shown in FIG. 11, in a centrifugal compressor 204 schematically constituted by a rotor 202 having an impeller 202 b provided on a shaft 202 a and a housing 203 that accommodates the rotor 202, an impeller outer peripheral portion 202 c in the vicinity of the impeller 202 b inlet. Or the seal device 1 or the seal described above in the radial clearance between the shaft 202a and the housing inner peripheral portion 203b on the downstream side of the rotor 202 in the axial direction. The apparatus 101 can be applied.
Thereby, vibration can be stably suppressed in a wide rotation range of the rotor 202.

  In the above-described embodiment, the swirl breaker portion 21 extends in the radial direction. However, the swirl breaker portion 21 may extend in the axial direction or the tangential direction as long as it is on the radial side. Even in this case, by setting the swirl breaker portion 21 to be rotatable around the extending direction, the angle of attack α can be changed with a small number of operations.

  In the embodiment described above, the movable mechanism 30 is configured to change the inclination angle α of the swirl breaker portion 21 by providing the outer ring member 31 and the connecting member 33. However, the mechanism of the movable mechanism 30 has been described above. The thing using not only a thing but various link mechanisms and cam mechanisms can be used.

  In the above-described embodiment, the swirl breaker portion 21 is positioned on the upstream side in the axial direction of the labyrinth seal 10. However, instead of the labyrinth seal 10, another seal (parallel annular seal or parallel grooved seal) is used. You may make it the structure which provides the swirl breaker part 21 in the axial direction upstream.

DESCRIPTION OF SYMBOLS 1,101 ... Sealing device 2,202 ... Rotor 3,203 ... Housing (stator)
4 ... Fluid machine C (C1, C2) ... Swirl S ... Gap 10 ... Labyrinth seal (seal part)
21 ... Swirl Breaker (Swirl Breaker)
121 ... Storage unit 122 ... Control unit 202 ... Rotor 204 ... Centrifugal compressor (fluid machine)
α: Inclination angle formed by the reference center line P of the swirl breaker portion 21 with respect to the axial direction β: Angle of attack α _j formed by the reference center line P of the swirl breaker portion 21 with respect to the swirling flow C ... Optimum tilt angle that can minimize the flow velocity

Claims (5)

A seal portion for sealing a radial gap formed between a rotor provided rotatably and a stator surrounding the rotor;
A swirl breaker extending radially inward from the stator and blocking a swirling flow flowing in the circumferential direction through the gap,
The swirl breaker is provided on a higher pressure side than the seal portion in the axial direction, and the angle of attack with respect to the swirl flow can be changed.   The seal device according to claim 1, wherein the swirl breaker is provided so as to be rotatable around an extending direction of the swirl breaker. A sensor unit for measuring the flow of the swirling flow;
A control unit for controlling the angle of attack of the swirl breaker,
The said control part controls the said angle of attack so that the said swirl breaker may cross | intersect the said swirl flow based on the measured value input from the said sensor part. Sealing device. A storage unit that stores an optimum inclination angle that is the inclination angle formed by the swirl breaker with respect to the axial direction and that minimizes the speed of the swirling flow for each different rotation speed of the rotor;
A control unit for controlling the angle of attack of the swirl breaker,
The sealing device according to claim 1, wherein the control unit controls the angle of attack so that the inclination angle becomes an optimum inclination angle in accordance with the number of rotations of the rotor.   A fluid machine comprising the sealing device according to any one of claims 1 to 4.

Images