Seal device, seal system, and rotary machine

Abstract

This seal device comprises: a movable seal member disposed in a first gap formed between a stationary member and a rotating member of a rotary machine; a holding member for supporting the movable seal member, which is disposed at a radially inner side, such that the movable seal member is movable along the radial direction; and a plurality of biasing devices that bias the movable seal member radially outward along the radial direction. The holding member or the movable seal member includes a first protrusion protruding toward the other along the radial direction, the other of the holding member and the movable seal member includes a first recess that can be engaged with the first protrusion, and each of the first protrusion and the first recess is disposed between an upper end-side biasing device disposed at an upper end side of the holding member in the circumferential direction and a lower end-side biasing device disposed at a lower end side thereof, and has a side surface extending along the radial direction when viewed from the axial direction, with the side surfaces slidably facing each other.

Description

Seal device, seal system and rotating machine

[0001] This application claims priority to Japanese Patent Application No. 2023-106867, filed on June 29, 2023, with the Japan Patent Office, the contents of which are incorporated herein by reference.

[0002] BACKGROUND ART A sealing device having a structure in which a movable sealing member can move radially depending on the operating state of the rotary machine is sometimes used as a sealing device for reducing fluid leakage through a gap between a rotating member and a stationary member in a rotary machine such as a gas turbine or a steam turbine.

[0003] In the sealing device (self-adjusting seal) described in Patent Document 1, movable sealing members (movable seal rings) are arranged above and below the rotating member in an annular gap between the rotating member and a stationary member, and fixed sealing members (fixed seal rings) are arranged on each side of the rotating member in the gap. In Patent Document 1, the movable sealing members arranged above and below the rotating member are configured to be movable in the vertical direction (radial direction) depending on the operating state of the rotary machine, etc.

[0004] In the sealing device described in Patent Document 1, when the rotary machine is in a start-stop operation or stopped state, the movable seal member is biased radially outward by the elastic member, thereby maintaining a large clearance between the rotating member and the movable seal member. Meanwhile, when the rotary machine is in a loaded operation state, the pressure of the high-pressure working fluid acts on the outer peripheral surface of the movable seal member, applying a radially inward force (i.e., a force that resists the biasing force of the elastic member) to the movable seal member. This displaces the movable seal member radially inward compared to when the rotary machine is in a start-stop operation or stopped state, thereby maintaining a small clearance between the rotating member and the movable seal member.

[0005] Japanese Patent Application Laid-Open No. 2021-124020

[0006] However, because the sealing device described in Patent Document 1 has a structure that makes it impossible to reduce the clearance between the rotating member and the fixed seal member, it is sometimes practiced to replace the fixed seal member with a movable seal member and replace all seal members disposed in the annular gap with movable seal members. When one circumferential end of the movable seal member is disposed higher than the other end, the operating direction of the movable seal member differs from the direction of gravity, and the movable seal member may tilt relative to the operating direction during operation. When the movable seal member tilts relative to the operating direction, the movement of the movable seal member during operation becomes poor, which may result in malfunction of the movable seal member.

[0007] In view of the above circumstances, an object of at least one embodiment of the present disclosure is to provide a seal device that can suppress malfunction of a movable seal member, and a seal system and a rotary machine that include the seal device.

[0008] a first recess with which the first protrusion can be engaged; a second recess with which the first protrusion can be engaged; a second recess with which the second protrusion can be engaged; a second recess with which the second protrusion can be engaged; a third recess with which the second protrusion can be engaged; a fourth recess with which the second protrusion can be engaged; a fourth recess with which the second protrusion can be engaged; a fifth recess with which the second protrusion can be engaged; a fifth recess with which the second protrusion can be engaged; a fifth recess with which the second protrusion can be engaged; a fifth recess with which the second protrusion can be engaged; a fifth recess with which the second protrusion can be engaged; a fifth recess with which the second protrusion can be engaged; a fifth recess with which the second protrusion can be engaged; a fifth recess with which the second protrusion can be engaged; a fifth recess with which the second protrusion can be engaged; a fifth recess with which the second protrusion can be engaged; a fifth recess with which the second protrusion can be engaged; a fifth recess with which the second protrusion can be engaged; a fifth recess with which the second protrusion can be engaged; a fifth recess with which the second protrusion can be engaged; a fifth recess with which the second protrusion can be engaged; a fifth recess with which the second protrusion can be engaged; a fifth recess with which the second protrusion can be engaged; a sixth ... Each of the first convex portion and the first concave portion is provided between the upper end side urging device arranged at the lower end side in the circumferential direction and the lower end side urging device arranged at the upper end side, and has side surfaces extending along the radial direction and slidably facing each other.

[0009] A sealing system according to at least one embodiment of the present disclosure is a sealing system for sealing a first gap formed between a rotating member of a rotary machine and a stationary member arranged radially outside the rotating member, and comprises a plurality of sealing devices arranged in a circumferential direction in the first gap, each of the plurality of sealing devices being constituted by the sealing device.

[0010] A rotary machine according to at least one embodiment of the present disclosure includes: the seal system; the rotating member; and the stationary member.

[0011] According to at least one embodiment of the present disclosure, there are provided a seal device capable of suppressing malfunction of a movable seal member, a seal system including the seal device, and a rotary machine.

[0012] 1 is a schematic cross-sectional view of the vicinity of a first gap of a rotary machine according to an embodiment of the present disclosure, viewed from one side in the axial direction; FIG. 2 is a schematic view of a sealing device according to an embodiment of the present disclosure, viewed from one side in the axial direction; FIG. 3 is a schematic cross-sectional view along the axial direction of the vicinity of a first gap of a rotary machine according to an embodiment of the present disclosure; FIG. 4 is a schematic view of the vicinity of a central position of a retaining member of a sealing device according to an embodiment of the present disclosure, viewed from one side in the axial direction; FIG. 5 is a schematic view of the vicinity of a lower end of a sealing device according to an embodiment of the present disclosure, viewed from one side in the axial direction; FIG. 6 is a schematic view of the vicinity of an upper end of a sealing device according to an embodiment of the present disclosure, viewed from one side in the axial direction; FIG. 7 is an explanatory view for describing forces acting on a sealing device according to a comparative example; FIG. 8 is an explanatory view for describing moments acting on a sealing device according to a comparative example; FIG. 9 is an explanatory view for describing changes in moment and actuation amount relative to load in a sealing device according to a comparative example; FIG. 10 is an explanatory view for describing moments acting on a sealing device according to an embodiment of the present disclosure; FIG. 11 is an explanatory view for describing changes in moment and actuation amount relative to load in a sealing device according to an embodiment of the present disclosure;

[0013] Hereinafter, several embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of components described as embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the present disclosure. "Extending along a certain direction" is not limited to extending in a certain direction, but also includes extending in a direction inclined within a predetermined angle (e.g., ±10°) relative to the certain direction.

[0014] (Rotary machine) Fig. 1 is a schematic cross-sectional view of a first gap G1 and its vicinity of a rotary machine 10 according to an embodiment of the present disclosure, viewed from one axial side. As shown in Fig. 1, the rotary machine 10 according to some embodiments includes a rotating member 11 and a stationary member 12 arranged radially outward of the rotating member 11. A first gap G1 is formed between the rotating member 11 and the stationary member 12. Note that examples of the rotary machine 10 according to the present disclosure include a gas turbine and a steam turbine.

[0015] The rotating member 11 is configured to rotate about a rotation axis LA (radial center) when the rotating machine 10 is driven. The rotating member 11 includes at least a rotating shaft 11A that extends along the rotation axis LA and is configured to rotate about the rotation axis LA (radial center). Note that the rotating member 11 may further include another member that is fixed to the rotating shaft 11A and rotates about the rotation axis LA (radial center) in conjunction with the rotation of the rotating shaft 11A.

[0016] Hereinafter, the direction in which the rotation axis LA of the rotating member 11 extends is defined as the axial direction of the rotating member 11 (rotating machine 10), the direction perpendicular to the rotation axis LA is defined as the radial direction of the rotating member 11 (rotating machine 10), and the circumferential direction around the rotation axis LA is defined as the circumferential direction of the rotating member 11 (rotating machine 10). Hereinafter, the axial direction, radial direction, and circumferential direction of the rotating member 11 (rotating machine 10) may be simply referred to as the axial direction, radial direction, and circumferential direction.

[0017] The stationary member 12 is configured to remain stationary (not rotate) even when the rotating member 11 rotates when the rotary machine 10 is driven. The stationary member 12 includes at least a housing 12A configured to rotatably accommodate the rotating member 11. The stationary member 12 may further include another member fixed to the housing 12A. The housing 12A may accommodate and support a bearing (not shown) that rotatably supports the rotating member 11.

[0018] The rotating member 11 has a rotating-side outer peripheral surface 111 that defines a first gap G1. The stationary member 12 has a stationary-side inner peripheral surface 121 that defines the first gap G1. The rotating-side outer peripheral surface 111, the stationary-side inner peripheral surface 121, and the first gap G1 are formed in an annular shape extending along the circumferential direction of the rotating machine 10. The rotating-side outer peripheral surface 111 is provided radially outward of the stationary-side inner peripheral surface 121 and faces the stationary-side inner peripheral surface 121 across the annular first gap G1. The first gap G1 is a radial gap formed between the rotating-side outer peripheral surface 111 and the stationary-side inner peripheral surface 121.

[0019] (Sealing Device, Sealing System) The sealing device 1 and the sealing system 13 according to some embodiments are sealing structures that are provided in the rotary machine 10 and seal the first gap G1 to suppress fluid leakage through the first gap G1. The sealing system 13 includes a plurality of sealing devices 1 arranged side by side in the circumferential direction in the first gap G1.

[0020] Fig. 2 is a schematic view of a seal device 1 according to an embodiment of the present disclosure as viewed from one side in the axial direction. Fig. 3 is a schematic cross-sectional view along the axial direction of a rotary machine 10 according to an embodiment of the present disclosure near a first gap G1. As shown in Fig. 2, the seal device 1 according to some embodiments includes a movable seal member 2, a holding member 3, and a plurality of biasing devices 4.

[0021] (Movable seal member) The movable seal member 2 includes a main body portion 21 having an arc shape that extends circumferentially in the first gap G1, as shown in Fig. 1. As shown in Fig. 2, an upper end 22, which is one end of the main body portion 21 in the circumferential direction, is positioned higher than a lower end 23, which is the other end of the main body portion 21 in the circumferential direction.

[0022] (Holding member) As shown in Fig. 1, the holding member 3 supports the movable seal member 2 arranged radially inside so as to be movable along the radial direction. The holding member 3 is supported by the stationary member 12. The holding member 3 includes a main body portion 31 having an arc shape extending along the circumferential direction so as to cover the radial outside of the main body portion 21 of the movable seal member 2. As shown in Fig. 2, an upper end 32, which is one end in the circumferential direction of the main body portion 31, is positioned higher than a lower end 33, which is the other end in the circumferential direction.

[0023] In the illustrated embodiment, an arc-shaped or annular groove 122 extending circumferentially is formed in the stationary-side inner circumferential surface 121 of the stationary member 12. The groove 122 is recessed radially outward from the stationary-side inner circumferential surface 121. The outer periphery of the main body 21 of the movable seal member 2 and the retaining member 3 are housed inside the groove 122.

[0024] The first gap G1 has a higher pressure on one axial side of the movable seal member 2 than on the other axial side. In other words, the first gap G1 includes a low-pressure section PS2 provided on the other axial side of the movable seal member 2 and a high-pressure section PS1 provided on the one axial side of the movable seal member 2. The main body 21 has an outer peripheral surface that faces an inner circumferential surface of the main body 31 of the holding member 3 with a radial gap therebetween. The radial gap formed between the outer peripheral surface of the main body 21 and the inner circumferential surface of the holding member 3 can communicate with the high-pressure section PS1, for example, via an axial gap formed between an end face on one or the other axial side of the main body 21 and a wall surface of the groove 122 facing the end face, and the pressure of the fluid from the high-pressure section PS1 acts on the outer circumferential surface of the main body 21.

[0025] 2, the movable seal member 2 may have at least one through hole 24 formed therein, penetrating from the inner peripheral surface to the outer peripheral surface of the main body portion 21. The holding member 3 may have at least one through hole 34 formed therein, penetrating from the inner peripheral surface to the outer peripheral surface of the main body portion 31. The fluid from the high-pressure section PS1 may be able to flow into a gap formed between the outer peripheral surface of the main body portion 21 and the inner peripheral surface of the holding member 3 via at least one of the through hole 24 and the through hole 34.

[0026] In the embodiment shown in FIG. 2 , the upper end 32 of the holding member 3 is formed with an upper end convex portion 321 that protrudes radially inward, and the upper end 22 of the movable seal member 2 is formed with an upper end recess 221 that is recessed radially inward and into which the upper end convex portion 321 can be loosely inserted. A first upper end gap CG4, which is a circumferential gap, is formed between the upper end convex portion 321 and the upper end recess 221 in the circumferential direction. The lower end 33 of the holding member 3 is formed with a lower end convex portion 331 that protrudes radially inward, and the lower end 23 of the movable seal member 2 is formed with a lower end recess 231 that is recessed radially inward and into which the lower end convex portion 331 can be loosely inserted. A first lower end gap CG5, which is a circumferential gap, is formed between the lower end convex portion 331 and the lower end recess 231 in the circumferential direction.

[0027] 3, a plurality of seal fins 25 formed in a thin plate shape protruding toward the rotation-side outer peripheral surface 111 are provided on the inner peripheral surface facing the rotation-side outer peripheral surface 111 of the main body portion 21. In some embodiments, at least one seal fin 112 formed in a thin plate shape protruding toward the inner peripheral surface of the main body portion 21 may be provided on the rotation-side outer peripheral surface 111 of the rotating member 11 facing the inner peripheral surface of the main body portion 21.

[0028] (Using Device) Each of the multiple urging devices 4 is configured to urge the movable seal member 2 radially outward relative to the holding member 3. The multiple urging devices 4 are arranged at different positions in the circumferential direction. Each of the multiple urging devices 4 includes at least one upper-end urging device 4U arranged on the upper end side of the holding member 3 in the circumferential direction, and at least one lower-end urging device 4L arranged on the lower end side of the holding member 3 in the circumferential direction. Note that the upper end side of the holding member 3 in this paragraph refers to the upper end 32 side of the central position (circumferential central position) 30 of the holding member 3 in the circumferential direction, and the lower end side of the holding member 3 in this paragraph refers to the lower end 33 side of the central position 30 of the holding member 3 in the circumferential direction.

[0029] In the illustrated embodiment, the at least one upper-end urging device 4U includes a plurality of upper-end urging devices 4U1, 4U2. The first upper-end urging device 4U1 is disposed closer to the center position 30 (closer to the lower end 33) in the circumferential direction than the second upper-end urging device 4U2. The at least one lower-end urging device 4L includes a plurality of lower-end urging devices 4L1, 4L2. The first lower-end urging device 4L1 is disposed closer to the center position 30 (closer to the upper end 32) in the circumferential direction than the second lower-end urging device 4L2.

[0030] The holding member 3 supports the movable seal member 2 movably in the radial direction via a plurality of biasing devices 4. In the embodiment shown in FIG. 3 , each of the plurality of biasing devices 4 includes a head 41, a shaft 42, and a biasing member 43 configured to be expandable and contractible in the radial direction. The head 41 is accommodated in an accommodation groove 35 formed in the outer peripheral surface of the main body 31 of the holding member 3 and is formed with a larger diameter than the shaft 42. The shaft 42 extends in the radial direction, with one end connected to the head 41 and the other end connected to the main body 21 of the movable seal member 2. The biasing member 43 is disposed between a bottom surface 351 of the accommodation groove 35 and an opposing surface 411 that faces the bottom surface 351 of the head 41 via a radial gap, with one end abutting the opposing surface 411 and the other end abutting the bottom surface 351. In the embodiment shown in FIG. 3 , the biasing member 43 includes a compression coil spring arranged to cover the outer periphery of the shaft 42.

[0031] 3, a threaded portion 44 formed on the outer peripheral surface of the other end of the shaft portion 42 is adapted to threadably engage with a threaded hole 26 provided on the outer peripheral surface of the main body portion 21 of the movable seal member 2. In this case, it is easy to adjust the radial gap formed between the bottom surface 351 of the accommodation groove 35 and the opposing surface 411 of the head portion 41, thereby facilitating adjustment of the initial strain of the biasing member 43. Note that each of the multiple biasing devices 4 is not limited to the embodiment shown in the drawings. For example, the shaft portion 42 may be connected to the main body portion 21 of the movable seal member 2 by shrink fitting, welding, or the like.

[0032] When the rotary machine 10 is in a start-up / shutdown state or is stopped, the movable seal member 2 is urged radially outward by the multiple urging devices 4, so that a large clearance is maintained between the rotating member 11 and the main body 21 of the movable seal member 2. On the other hand, when the rotary machine 10 is in a load operation, the pressure of the fluid on the high-pressure side (the high-pressure section PS1 side) acts on the outer circumferential surface of the movable seal member 2, applying a radially inward force (i.e., a force that resists the urging force of the urging devices 4) to the movable seal member 2. As a result, the movable seal member 2 is displaced radially inward compared to when the rotary machine 10 is in a start-up / shutdown state or the like, so that a small clearance is maintained between the rotating member 11 and the main body 21 of the movable seal member 2.

[0033] (First convex portion, first concave portion) Fig. 4 is a schematic view of the vicinity of a central position 30 of the retaining member 3 of the seal device 1 according to an embodiment of the present disclosure, viewed from one side in the axial direction. Fig. 5 is a schematic view of the vicinity of a lower end 33 of the retaining member 3 of the seal device 1 according to an embodiment of the present disclosure, viewed from one side in the axial direction. Fig. 6 is a schematic view of the vicinity of an upper end 32 of the retaining member 3 of the seal device 1 according to an embodiment of the present disclosure, viewed from one side in the axial direction. In the seal device 1 according to some embodiments, as shown in Figs. 2 and 4 , one of the retaining member 3 or the movable seal member 2 includes a first convex portion 5 that protrudes radially toward the other of the retaining member 3 or the movable seal member 2, and the other of the retaining member 3 or the movable seal member 2 includes a first concave portion 6 with which the first convex portion 5 can engage.

[0034] As shown in FIG. 2 , the first protrusion 5 and the first recess 6 are each provided in a circumferential range between the upper end biasing device 4U1, which is located at the lowest end in the circumferential direction, and the lower end biasing device 4L1, which is located at the highest end in the circumferential direction. As shown in FIG. 4 , the first protrusion 5 includes an upper end side surface 51, which is the upper end surface in the circumferential direction, and a lower end side surface 52, which is the lower end surface in the circumferential direction. The first recess 6 includes an upper end side surface 61 formed above the upper end side surface 51 of the first protrusion 5 and facing the upper end side surface 51, and a lower end side surface 62 formed below the lower end side surface 52 of the first protrusion 5 and facing the lower end side surface 52. Each of the upper end side surface 51, the lower end side surface 52, the upper end side surface 61, and the lower end side surface 62 extends radially.

[0035] The upper end side surfaces 51, 61 of the first convex portion 5 and the first concave portion 6 slidably face each other. As shown in FIG. 4 , gravity FG acting on the movable seal member 2 maintains the upper end side surfaces 51, 61 in sliding contact with each other during operation of the movable seal member 2. A circumferential gap CG1 is formed between the lower end side surfaces 52, 62 to prevent contact between the retaining member 3 and the movable seal member 2 other than at the upper end side surfaces 51 and 61 during operation of the movable seal member 2. The movable seal member 2 can move upward in the circumferential direction by the circumferential gap CG1 relative to the retaining member 3 that supports the movable seal member 2. In other words, the circumferential gap CG1 provides a circumferential movement allowance for the movable seal member 2.

[0036] (Sealing Device According to Comparative Example) Fig. 7 is an explanatory diagram illustrating forces acting on the sealing device 01 according to the comparative example. Fig. 8 is an explanatory diagram illustrating moments acting on the sealing device 01 according to the comparative example. Fig. 9 is an explanatory diagram illustrating changes in the moment and actuation amount relative to a load in the sealing device 01 according to the comparative example. The sealing device 01 according to the comparative example does not have the first convex portion 5 and the first concave portion 6 described above, and the upper end 22 of the movable sealing member 2 is guided by an upper end stopper 91 attached to the upper end 32 of the holding member 3. Furthermore, the lower end 23 of the movable sealing member 2 is guided by a lower end stopper 92 attached to the lower end 33 of the holding member 3.

[0037] 7, the movable seal member 2 operates in the operating direction DM, i.e., radially inward, at rated load. The biasing forces FS (FS1, FS2, FS3, FS4) of the multiple biasing devices 4 act radially outward, while the pressure FP of the high-pressure fluid acting on the outer peripheral surface of the movable seal member 2 acts radially inward. Gravity FG acting on the movable seal member 2 acts radially inward in a direction different from the operating direction DM.

[0038] In the sealing device 01 according to the comparative example, gravity FG acting on the movable seal member 2 causes the lower end 23 of the movable seal member 2 to contact the lower end stopper 92. CM1 shown in FIG. 8 is the origin (center of rotation) when calculating the moment acting on the movable seal member 2 of the sealing device 01. The origin CM1 is located at the lower end 23 of the movable seal member 2. In FIG. 8, the rotational direction (clockwise direction in FIG. 8) in which the moment MG acting on the movable seal member 2 due to gravity FG acts is defined as the positive direction (+), and the side opposite to the positive direction (+) is defined as the negative direction (-). The moment MS acting on the movable seal member 2 due to the biasing forces FS of the multiple biasing devices 4 acts in the negative direction (-), while the moment MP acting on the movable seal member 2 due to the pressure FP of the high-pressure fluid acts in the positive direction (+).

[0039] 9 shows a graph with the load L of the rotary machine 10 on the horizontal axis and the moment M acting on the movable seal member 2 and the radial operating amount ST of the movable seal member 2 on the vertical axis. When the load L of the rotary machine 10 exceeds a lower threshold L1, the movable seal member 2 begins to operate, and continues to operate until the load L reaches an upper threshold L2. The moment M is a composite moment obtained by combining the moments MG, MS, and MP acting on the movable seal member 2. As shown in FIG. 9, in the sealing device 01 according to the comparative example, the moment M acting on the movable seal member 2 is large.

[0040] In the sealing device 01 of the comparative example, during operation of the movable sealing member 2, the lower end 23 comes into contact with the lower end stopper 92, and a moment M acts due to the friction generated between the lower end 23 and the lower end stopper 92, causing the upper end 22 of the movable sealing member 2 to operate before the lower end 23. As a result, the movable sealing member 2 tilts relative to the operating direction DM during operation, and there is a risk that operation of the lower end 23 side of the movable sealing member 2 will be delayed.

[0041] FIG. 10 is an explanatory diagram illustrating a moment acting on a sealing device 1 according to an embodiment of the present disclosure. FIG. 11 is an explanatory diagram illustrating changes in moment and actuation amount relative to a load in a sealing device 1 according to an embodiment of the present disclosure. In the sealing device 1, gravity FG acting on the movable seal member 2 causes the upper end side surface 51 of the first convex portion 5 to contact the upper end side surface 61 of the first recessed portion 6. CM2 shown in FIG. 10 is the origin (center of rotation) when calculating the moment acting on the movable seal member 2 of the sealing device 1. The origin CM2 is located at the contact point between the upper end side surface 51 of the first convex portion 5 and the upper end side surface 61 of the first recessed portion 6 when the movable seal member 2 is not in operation.

[0042] 10, the rotational direction (clockwise direction in FIG. 10) in which the moment MG acting on the movable seal member 2 due to gravity FG acts is designated as the positive direction +, and the direction opposite to the positive direction + is designated as the negative direction -. In the seal device 1, compared to the seal device 01 according to the comparative example, the moment balance between the upper and lower end portions of the movable seal member 2 during operation of the movable seal member 2 is adjusted, and the biasing forces FS (FS1, FS2, FS3, FS4) of the multiple biasing devices 4 and the pressure FP of the high-pressure fluid acting on the outer peripheral surface of the movable seal member 2 are balanced. This makes it possible to prevent the movable seal member 2 from tilting relative to the operating direction during operation.

[0043] 11 shows a graph with the load L of the rotary machine 10 on the horizontal axis and the moment M acting on the movable seal member 2 and the radial operating amount ST of the movable seal member 2 on the vertical axis. When the load L of the rotary machine 10 exceeds a lower threshold L1, the movable seal member 2 begins to operate, and continues to operate until the load L reaches an upper threshold L2. The moment M is a composite moment obtained by combining the moments MG, MS, and MP acting on the movable seal member 2. As shown in FIG. 11 , in the sealing device 1, the moment M acting on the movable seal member 2 is smaller than in the sealing device 01 according to the comparative example, and is constant regardless of the load L.

[0044] According to the above configuration, gravity acting on the movable seal member 2 maintains the sliding contact between the upper end side surfaces 51, 61 of the first convex portion 5 and the first concave portion 6. Furthermore, by providing the first convex portion 5 and the first concave portion 6 between the upper end biasing device 4U1 and the lower end biasing device 4L1 in the circumferential direction, the moment balance between the upper end portion and the lower end portion of the movable seal member 2 is adjusted during operation of the movable seal member 2. This prevents the movable seal member 2 from tilting relative to the operating direction during operation, which would cause delays in operation of the lower end 23 of the movable seal member 2, thereby preventing malfunction of the movable seal member 2.

[0045] 2 and 4 , in the sealing device 1 according to some embodiments, the first convex portion 5 and the first concave portion 6 are each provided in a circumferential range that includes a central position 30 in the circumferential direction of the holding member 3. In this case, by providing the first convex portion 5 and the first concave portion 6 near the central position 30 of the holding member 3, the moment balance between the upper end portion and the lower end portion of the movable seal member 2 during operation of the movable seal member 2 is suitably adjusted. This effectively prevents the movable seal member 2 from tilting with respect to the operating direction during operation.

[0046] In some embodiments of the sealing device 1, as shown in FIG. 4 , the holding member 3 includes the first convex portion 5, and the movable seal member 2 includes the first concave portion 6. In this case, during operation of the movable seal member 2, the upper end side surface 61 of the first concave portion 6 provided in the movable seal member 2 is guided by the upper end side surface 51 of the first convex portion 5 provided in the holding member 3. This prevents the movable seal member 2 from tilting relative to the operating direction during operation and delaying the operation of the lower end 23 of the movable seal member 2. Furthermore, when the movable seal member 2 includes the first concave portion 6, the weight of the movable seal member 2 can be reduced compared to when the movable seal member 2 includes the first convex portion 5, and the gravity FG acting on the movable seal member 2 can be reduced. By reducing the gravity FG acting on the movable seal member 2, the moment balance between the upper and lower end portions of the movable seal member 2 is improved.

[0047] In the sealing device 1 according to some other embodiments, the holding member 3 includes the first recess 6, and the movable seal member 2 includes the first protrusion 5. In this case, during operation of the movable seal member 2, the upper end side surface 51 of the first protrusion 5 provided on the movable seal member 2 is guided by the upper end side surface 61 of the first recess 6 provided on the holding member 3. This prevents the movable seal member 2 from tilting with respect to the operating direction during operation, and prevents delay in operation of the lower end 23 side of the movable seal member 2.

[0048] 2 , in the seal device 1 according to some embodiments, the holding member 3 includes a plurality of accommodation grooves 35 that respectively accommodate the plurality of biasing devices 4, and a plurality of second protrusions 7 that protrude radially inward in circumferential ranges that respectively include the plurality of accommodation grooves 35. The movable seal member 2 includes a plurality of second recesses 8 into which the plurality of second protrusions 7 are inserted, respectively.

[0049] In the illustrated embodiment, as shown in Figures 2 and 3, each of the multiple second protrusions 7 protrudes radially inward from the inner peripheral surface of the main body portion 31 of the retaining member 3 in a circumferential range including the accommodation groove 35 corresponding to the second protrusion 7. The second protrusion 7 includes an outer peripheral surface 71 extending radially and an inner end face 72 in the radial direction. As shown in Figures 2 and 3, each of the multiple second recesses 8 is formed to be recessed radially inward from the outer peripheral surface of the main body portion 21 of the movable seal member 2 in a circumferential range including the second protrusion 7 corresponding to the second recess 8. The second recess 8 includes an inner peripheral surface 81 facing the outer peripheral surface 71 and a groove bottom surface 82 facing the end face 72. In addition, when the movable seal member 2 is positioned at the radially outermost position within the operating range of the movable seal member 2, a radial gap may be formed between the groove bottom surface 82 and the end face 72, or the groove bottom surface 82 and the end face 72 may abut against each other.

[0050] According to the above configuration, by providing the second convex portions 7 in a circumferential range that includes each of the multiple accommodating grooves 35 of the holding member 3, the radial dimension of the holding member 3 can be reduced. Furthermore, by providing the movable seal member 2 with multiple second recesses 8 into which the multiple second convex portions 7 are respectively inserted, the radial dimension of the movable seal member 2 can be reduced. This allows the radial dimension of the seal device 1 to be reduced. Furthermore, by providing the movable seal member 2 with multiple second recesses 8, the weight of the movable seal member 2 can be reduced, and gravity acting on the movable seal member 2 can be reduced. By reducing gravity acting on the movable seal member 2, the moment balance between the upper end portion and the lower end portion of the movable seal member 2 is improved.

[0051] 2 , in the seal device 1 according to some embodiments, each of the plurality of second recesses 8 described above has a second gap G2 (CG2, CG3) that is a circumferential gap formed between the second recesses 8 and the second protrusion 7 inserted into the second recesses 8 in the circumferential direction. The second gap G2 includes a second upper-end gap CG2 that is a circumferential gap formed on the upper end side of the second protrusion 7 in the circumferential direction, and a second lower-end gap CG3 that is a circumferential gap formed on the lower end side of the second protrusion 7 in the circumferential direction. Regardless of the operating state of the movable seal member 2, the inner circumferential surface 81 of the second recesses 8 faces the outer circumferential surface 71 of the second protrusion 7 via a gap.

[0052] According to the above configuration, the second gap G2, which is a circumferential gap, is formed between the second convex portion 7 and the second recessed portion 8, thereby preventing contact between the second convex portion 7 and the second recessed portion 8. If the second convex portion 7 and the second recessed portion 8 were to come into contact, friction would occur between the second convex portion 7 and the second recessed portion 8, which could cause the movable seal member 2 to tilt relative to the operating direction during operation. However, by preventing the second convex portion 7 from contacting the second recessed portion 8, it is possible to prevent the movable seal member 2 from tilting relative to the operating direction due to the friction during operation. This prevents malfunction of the movable seal member 2.

[0053] 6, in the sealing device 1 according to some embodiments, when the upper end side surfaces 51, 61 of the holding member 3 and the movable seal member 2 are in contact with each other (see FIG. 4), the upper end 32 of the holding member 3 is located a distance (circumferential distance) D1 circumferentially above the upper end 22 of the movable seal member 2. In one embodiment, the distance D1 is 0.1 mm or more and 1 mm or less.

[0054] According to the above configuration, by having the upper end 32 of the holding member 3 protrude further upward in the circumferential direction than the upper end 22 of the movable seal member 2, it is possible to prevent the upper end 22 of the movable seal member 2 from coming into contact with another member located on the upper end side in the circumferential direction relative to the movable seal member 2, even when the movable seal member 2 is located at the radially innermost position within the operating range of the movable seal member 2. An example of this other member is the movable seal member 2 of another seal device 1 arranged adjacent to the lower end side in the circumferential direction.

[0055] 5, in the sealing device 1 according to some embodiments, when the upper end side surfaces 51, 61 of the holding member 3 and the movable seal member 2 are in contact with each other (see FIG. 4), the lower end 33 of the holding member 3 is located a distance (circumferential distance) D2 lower in the circumferential direction than the lower end 23 of the movable seal member 2. In one embodiment, the distance D2 is 0.6 mm or more and 1.5 mm or less.

[0056] According to the above configuration, by having the lower end 33 of the holding member 3 protrude further downward in the circumferential direction than the lower end 23 of the movable seal member 2, it is possible to prevent the lower end 23 of the movable seal member 2 from coming into contact with another member located on the lower end side in the circumferential direction relative to the movable seal member 2, even when the movable seal member 2 is located at the radially innermost position within the operating range of the movable seal member 2. An example of this other member is the movable seal member 2 of another seal device 1 arranged adjacent to the upper end side in the circumferential direction.

[0057] In the seal device 1 according to some embodiments, the distance D1 is greater than the distance D2. There is a possibility that the movable seal member 2 may shift toward the upper end in the circumferential direction by an amount corresponding to the circumferential gap (the circumferential movement allowance of the movable seal member 2) formed between the lower end side surface 52 and the lower end side surface 62 in the circumferential direction. For this reason, the distance D2 is preferably equal to or greater than the distance D1 plus the circumferential movement allowance of the movable seal member 2. In one embodiment, the circumferential movement allowance of the movable seal member 2 is 0.5 mm.

[0058] According to the above configuration, if the first convex portion 5 becomes misaligned inside the first concave portion 6 during operation of the movable seal member 2 and the sliding contact between the upper end side surfaces 51, 61 of the first convex portion 5 and the first concave portion 6 is released, the movable seal member 2 may shift circumferentially toward the upper end relative to the holding member 3. By taking into consideration the circumferential movement allowance of the movable seal member 2 toward the upper end and making the distance D1 greater than the distance D2, even if the movable seal member 2 shifts circumferentially toward the upper end, the upper end 22 of the movable seal member 2 can be prevented from protruding above the upper end 32 of the movable seal member 2. This prevents the upper end 22 of the movable seal member 2 from coming into contact with other members even if the movable seal member 2 is tilted with respect to the operating direction during operation.

[0059] Each of the above-mentioned first upper end gap CG4, first lower end gap CG5, second upper end gap CG2 and second lower end gap CG3 is larger than the circumferential movement allowance of the movable seal member 2, i.e., the above-mentioned circumferential gap CG1 (see Figure 4), in order to suppress contact between the movable seal member 2 and the retaining member 3 when the movable seal member 2 shifts toward the upper end in the circumferential direction.

[0060] 12 is an explanatory diagram illustrating forces and moments acting on the seal device 1 according to an embodiment of the present disclosure. In the seal device 1 according to some embodiments, the at least one upper-end biasing device 4U is configured to have a greater biasing force than the at least one lower-end biasing device 4L.

[0061] In Figure 12, the rotational direction (clockwise in Figure 8) in which the moment MG acting on the movable seal member 2 due to gravity FG acts is designated as the positive direction (+), and the opposite side to the positive direction (+) is designated as the negative direction (-). Moments MS1 and MS2 acting on the movable seal member 2 due to the biasing forces FS1 and FS2 of the upper-end biasing devices 4U (4U1, 4U2) act in the negative direction (-). In contrast, moments MS3 and MS4 acting on the movable seal member 2 due to the biasing forces FS3 and FS4 of the lower-end biasing devices 4L (4L1, 4L2) act in the positive direction (+). By making at least one of the biasing forces FS1 and FS2 larger than the biasing forces FS3 and FS4, the resultant moment MS acting in the negative direction (-) due to the biasing forces FS of the multiple biasing devices 4 can be increased, thereby reducing the influence of the moment MG on the movable seal member 2 caused by gravity.

[0062] Possible measures to increase the biasing force include, for example, using a compression coil spring (biasing member) for the upper end biasing device 4U that has a higher spring constant than the compression coil spring (biasing member) for the lower end biasing device 4L, or making the gap between the bottom surface 351 on which the biasing member of the upper end biasing device 4U is arranged and the opposing surface 411 smaller than the gap between the bottom surface 351 on which the biasing member of the lower end biasing device 4L is arranged and the opposing surface 411.

[0063] According to the above configuration, by making the biasing force of the upper-end biasing device 4U greater than the biasing force of the lower-end biasing device 4L, it is possible to eliminate the imbalance in the moment of the movable seal member 2 caused by gravity. By eliminating the imbalance in the moment of the movable seal member 2 caused by gravity, the moment balance between the upper end portion and the lower end portion of the movable seal member 2 is further improved.

[0064] 1, a seal system 13 according to some embodiments includes a plurality of seal devices 1 arranged side by side in the circumferential direction in the first gap G1 described above. Each of the plurality of seal devices 1 included in the seal system 13 is configured as the above-described seal device 1 including a movable seal member 2, a holding member 3, and a plurality of biasing devices 4.

[0065] According to the above configuration, the seal system 13 can suppress fluid leakage through the first gap G1 formed between the rotating member 11 and the stationary member 12. By suppressing malfunction of the movable seal members 2 of the multiple seal devices 1 that make up the seal system 13, it is possible to suppress deterioration of the sealing performance of the seal system 13 that would otherwise be caused by such malfunction. Furthermore, by suppressing malfunction of the movable seal members 2 of the multiple seal devices 1 that make up the seal system 13, it is possible to suppress contact between the movable seal members 2 of the multiple seal devices 1 that are arranged side by side in the circumferential direction. Furthermore, each of the multiple seal devices 1 can operate independently without being affected by adjacent seal devices 1.

[0066] In some embodiments, as shown in FIG. 1 , the seal system 13 includes the first gap G1, and the above-described seal devices 1 are disposed in each of the regions obtained by equally dividing the first gap G1 in the circumferential direction. In the embodiment shown in FIG. 1 , the first gap G1 is divided into eight regions, but the number of divisions is not limited to the illustrated example. The first gap G1 may be equally divided into an even number of regions, such as two, four, or six, in the circumferential direction, or an odd number of regions, such as three or five. The stationary member 12 of the rotary machine 10 may be configured so that it can be divided into two halves, an upper half positioned above a horizontal plane including the rotation axis LA, and a lower half positioned below the horizontal plane, during maintenance, etc. In such a case, when the seal system 13 needs to be divided into a region above and a region below the horizontal plane including the rotation axis LA, it is preferable that the first gap G1 be equally divided into an even number of regions in the circumferential direction so that it can be divided into upper and lower halves on the horizontal plane including the rotation axis LA.

[0067] In some other embodiments, the seal system 13 may include a stationary seal member (not shown) that is provided adjacent to the seal device 1 in the circumferential direction. In other words, the stationary seal member (not shown) may be arranged in at least one of a plurality of equally divided regions of the first gap G1. The stationary seal member is configured so as not to move in the radial direction.

[0068] 1 , a rotary machine 10 according to some embodiments includes the above-described rotating member 11, the above-described stationary member 12, and the above-described seal system 13. In this case, by suppressing malfunction of the movable seal members 2 of the multiple seal devices 1 constituting the seal system 13, it is possible to suppress deterioration in the sealing performance of the seal system 13 due to the malfunction, and therefore it is possible to effectively suppress fluid leakage through the first gap G1 in the rotary machine 10.

[0069] In this specification, expressions expressing relative or absolute arrangements, such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial," not only strictly express such arrangements, but also express a state in which there is a relative displacement with a tolerance or an angle or distance to the extent that the same function is obtained. For example, expressions expressing that things are in an equal state, such as "identical," "equal," and "homogeneous," not only express a state in which there is a strict equivalence, but also express a state in which there is a tolerance or a difference to the extent that the same function is obtained. Furthermore, in this specification, expressions expressing shapes such as a rectangular shape or a cylindrical shape not only express shapes such as a rectangular shape or a cylindrical shape in the strict geometric sense, but also express shapes including concave and convex portions, chamfered portions, etc., to the extent that the same effect is obtained. Furthermore, in this specification, the expressions "comprise," "include," or "have" a component are not exclusive expressions that exclude the presence of other components.

[0070] The present disclosure is not limited to the above-described embodiments, but also includes modifications to the above-described embodiments and appropriate combinations of these modifications.

[0071] The contents of the above-described embodiments can be understood, for example, as follows.

[0072] 1) A sealing device (1) according to at least one embodiment of the present disclosure is a sealing device (1) for sealing a first gap (G1) formed between a rotating member (11) of a rotary machine (10) and a stationary member (12) arranged radially outward of the rotating member (11), the sealing device (1) comprising: a movable sealing member (2) extending along a circumferential direction in the first gap (G1) and having one end (upper end 22) in the circumferential direction arranged higher than the other end (lower end 23); a holding member (3) for supporting the movable sealing member (2) arranged radially inward so as to be movable along the radial direction; and a plurality of biasing devices (4) each configured to bias the movable sealing member (2) radially outward relative to the holding member (3), the plurality of biasing devices (4) comprising: at least one upper-end biasing device (4U) arranged on an upper end (32) side of the holding member (3) in the circumferential direction; and at least one lower-end-side urging device (4L) arranged on the lower end (33) side of the holding member (3) in the circumferential direction, wherein one of the holding member (3) or the movable seal member (2) includes a first convex portion (5) that protrudes toward the other of the holding member (3) or the movable seal member (2) along the radial direction, and the other of the holding member (3) or the movable seal member (2) includes a first concave portion (6) with which the first convex portion (5) can engage, and each of the first convex portion (5) and the first concave portion (6) is provided between the upper-end-side urging device (4U1) arranged closest to the lower end (33) in the circumferential direction and the lower-end-side urging device (4L1) arranged closest to the upper end (31), and has side surfaces (51, 61) that extend along the radial direction and slidably face each other.

[0073] According to the configuration of 1), during operation of the movable seal member (2), gravity acting on the movable seal member (2) maintains a sliding contact state between the side surfaces (51, 61) of the first convex portion (5) and the first concave portion (6). Furthermore, by providing the first convex portion (5) and the first concave portion (6) between the upper end biasing device (4U1) and the lower end biasing device (4L1) in the circumferential direction, a moment balance is achieved between the upper end portion and the lower end portion of the movable seal member (2) during operation of the movable seal member (2). This prevents the movable seal member (2) from tilting relative to the operating direction during operation, which would otherwise cause a delay in operation of the lower end (23) of the movable seal member (2), thereby preventing malfunction of the movable seal member (2).

[0074] 2) In some embodiments, the seal device (2) described in 1) above, wherein the retaining member (3) includes the first convex portion (5), and the movable seal member (2) includes the first concave portion (6).

[0075] According to the configuration of 2) above, during operation of the movable seal member (2), the side surface (61) of the first recess (6) provided on the movable seal member (2) is guided by the side surface (51) of the first protrusion (5) provided on the holding member (3). This prevents the movable seal member (2) from tilting relative to the operating direction during operation, which would otherwise cause delay in operation of the lower end (23) of the movable seal member (2). Furthermore, when the movable seal member (2) is provided with the first recess (6), the weight of the movable seal member (2) can be reduced compared to when the movable seal member (2) is provided with the first protrusion (5), thereby reducing the gravity acting on the movable seal member (2). By reducing the gravity acting on the movable seal member (2), the moment balance between the upper end portion and the lower end portion of the movable seal member (2) is improved.

[0076] 3) In some embodiments, the seal device (2) described in 1) above, wherein the retaining member (3) includes the first recess (6), and the movable seal member (2) includes the first protrusion (5).

[0077] According to the configuration of 3), during operation of the movable seal member 2, the side surface 51 of the first convex portion 5 provided on the movable seal member 2 is guided by the side surface 61 of the first concave portion 6 provided on the holding member 3. This prevents the movable seal member 2 from tilting with respect to the operating direction during operation, and prevents delay in operation of the lower end 23 of the movable seal member 2.

[0078] 4) In some embodiments, in the seal device (1) described in any one of 1) to 3) above, the retaining member (3) includes a plurality of accommodating grooves (35) that respectively accommodate the plurality of biasing devices (4), and a plurality of second protrusions (7) that protrude radially inward in a circumferential range that includes each of the plurality of accommodating grooves (35) in the circumferential direction, and the movable seal member (2) includes a plurality of second recesses (8) into which the plurality of second protrusions (7) are respectively inserted.

[0079] According to the configuration 4) above, by providing the second convex portions (7) in a circumferential range that includes each of the multiple accommodation grooves (35) of the holding member (3), the radial dimension of the holding member (3) can be reduced. Furthermore, by providing the movable seal member (2) with multiple second recesses (8) into which the multiple second convex portions (7) are respectively inserted, the radial dimension of the movable seal member (2) can be reduced. This allows the radial dimension of the seal device (1) to be reduced. Furthermore, by providing the movable seal member (2) with multiple second recesses (8), the weight of the movable seal member (2) can be reduced, thereby reducing gravity acting on the movable seal member (2). By reducing gravity acting on the movable seal member (2), the moment balance between the upper end portion and the lower end portion of the movable seal member (2) is improved.

[0080] 5) In some embodiments, in the sealing device (1) described in 4) above, a second gap (G2) is formed, which is a circumferential gap formed between each of the plurality of second recesses (8) and the second protrusion (7) inserted into the second recess (8) in the circumferential direction.

[0081] According to the configuration of 5) above, the second gap (G2), which is a circumferential gap, is formed between the second convex portion (7) and the second concave portion (8), thereby preventing contact between the second convex portion (7) and the second concave portion (8). If the second convex portion (7) and the second concave portion (8) were to come into contact with each other, friction would occur between the second convex portion (7) and the second concave portion (8), which could cause the movable seal member (2) to tilt relative to the operating direction during operation. However, by preventing the second convex portion (7) from contacting the second concave portion (8), it is possible to prevent the movable seal member (2) from tilting relative to the operating direction due to the friction during operation. This prevents malfunction of the movable seal member (2).

[0082] 6) In some embodiments, in the sealing device (1) described in any of 1) to 5) above, when the side surfaces (51, 61) of the retaining member (3) and the movable seal member (2) are in contact with each other, the upper end (32) of the retaining member (3) is located a distance (circumferential distance) D1 closer to the upper end than the upper end (22) of the movable seal member (2) in the circumferential direction, and when the side surfaces (51, 61) of the retaining member (3) and the movable seal member (2) are in contact with each other, the lower end (33) of the retaining member (3) is located a distance (circumferential distance) D2 closer to the lower end than the lower end (23) of the movable seal member (2) in the circumferential direction.

[0083] According to the configuration 6) above, by having the upper end (32) of the holding member (3) protrude upward in the circumferential direction beyond the upper end (22) of the movable seal member (2), even when the movable seal member (2) is located at the radially innermost position within the operating range of the movable seal member (2), it is possible to prevent the upper end (22) of the movable seal member (2) from contacting another member located on the upper end side relative to the movable seal member (2). Furthermore, by having the lower end (33) of the holding member (3) protrude downward in the circumferential direction beyond the lower end (23) of the movable seal member (2), it is possible to prevent the lower end (23) of the movable seal member (2) from contacting another member located on the lower end side relative to the movable seal member (2), even when the movable seal member (2) is located at the radially innermost position within the operating range of the movable seal member (2).

[0084] 7) In some embodiments, the sealing device (1) described in 6) above, wherein the distance D1 is greater than the distance D2.

[0085] According to the configuration of 7) above, if the first convex portion (5) becomes misaligned within the first concave portion (6) during operation of the movable seal member (2), and the sliding contact between the side surfaces (51, 61) of the first convex portion (5) and the first concave portion (6) is released, the movable seal member (2) may shift toward the upper end in the circumferential direction relative to the retaining member (3). By taking into consideration the circumferential movement allowance of the movable seal member (2) toward the upper end and making the distance D1 greater than the distance D2, even if the movable seal member (2) shifts toward the upper end in the circumferential direction, the upper end (22) of the movable seal member (2) can be prevented from protruding above the upper end (32) of the retaining member (3). This prevents the upper end (22) of the movable seal member (2) from contacting other components, even if the movable seal member (2) tilts relative to the operating direction during operation.

[0086] 8) In some embodiments, in the sealing device (1) described in any one of 1) to 7) above, the at least one upper end side biasing device (4U) is configured to have a biasing force greater than that of the at least one lower end side biasing device (4L).

[0087] According to the configuration of 8) above, by making the biasing force of the upper end biasing device (4U) greater than the biasing force of the lower end biasing device (4L), it is possible to eliminate the imbalance in the moment of the movable seal member (2) caused by gravity. By eliminating the imbalance in the moment of the movable seal member (2) caused by gravity, the moment balance between the upper end portion and the lower end portion of the movable seal member (2) is further improved.

[0088] 9) In some embodiments, in the sealing device (1) described in any one of 1) to 8) above, the first convex portion (5) and the first concave portion (6) are each provided in a circumferential range including a central position (30) in the circumferential direction of the retaining member (3).

[0089] According to the configuration of 9), by providing the first convex portion (5) and the first concave portion (6) near the center position of the holding member (3), the moment balance between the upper end portion and the lower end portion of the movable seal member (2) during operation of the movable seal member (2) is suitably adjusted, thereby effectively preventing the movable seal member (2) from tilting relative to the operating direction during operation.

[0090] 10) A seal system (13) according to at least one embodiment of the present disclosure is a seal system (13) for sealing a first gap (G1) formed between a rotating member (11) of a rotary machine (10) and a stationary member (12) arranged radially outside the rotating member (11), and includes a plurality of seal devices (1) arranged in a line along the circumferential direction in the first gap (G1), each of which is constituted by a seal device (1) described in any one of 1) to 9) above.

[0091] According to the configuration of 10) above, the sealing system (13) can suppress fluid leakage through the first gap (G1) formed between the rotating member (11) and the stationary member (12). By suppressing malfunction of the movable sealing members (2) of the multiple sealing devices (1) constituting the sealing system (13), it is possible to suppress deterioration of the sealing performance of the sealing system (13) due to such malfunction. Furthermore, by suppressing malfunction of the movable sealing members (2) of the multiple sealing devices (1) constituting the sealing system (13), it is possible to suppress contact between the movable sealing members (2) of the multiple sealing devices (1) arranged side by side in the circumferential direction.

[0092] 11) A rotary machine (10) according to at least one embodiment of the present disclosure comprises: the seal system (13) described in 10); the rotating member (11); and the stationary member (12).

[0093] According to the configuration of 11) above, malfunction of each of the movable seal members (2) of the multiple seal devices (1) constituting the seal system (13) can be suppressed, thereby suppressing deterioration of the sealing performance of the seal system (13) due to the malfunction, and therefore fluid leakage through the first gap (G1) in the rotary machine (10) can be effectively suppressed.

[0094] REFERENCE SIGNS LIST 1 sealing device 2 movable sealing member 3 holding member 4 urging device 4L lower end side urging device 4U upper end side urging device 5 first convex portion 6 first concave portion 7 second convex portion 8 second concave portion 10 rotating machine 11 rotating member 12 stationary member 13 sealing system 21, 31 main body portion 22, 32 upper end 23, 33 lower end 24, 34 through hole 25, 112 seal fin 26 screw hole 30 central position 35 accommodation groove 41 head portion 42 shaft portion 43 urging member 44 threaded portion 51, 61 upper end side surface 52, 62 lower end side surface 71 outer peripheral surface 72 end surface 81 inner peripheral surface 82 groove bottom surface 91 upper end side stopper 92 lower end side stopper G1 first gap G2 Second gap

Claims

1. A sealing device for sealing a first gap formed between a rotating member of a rotary machine and a stationary member arranged radially outward of the rotating member, comprising: a movable seal member extending circumferentially in the first gap, with one end in the circumferential direction being arranged higher than the other end; a retaining member for supporting the movable seal member arranged on the inner side in the radial direction so as to be movable along the radial direction; and a plurality of biasing devices each configured to bias the movable seal member radially outward in the radial direction relative to the retaining member, the plurality of biasing devices including at least one upper end biasing device arranged on an upper end side of the retaining member in the circumferential direction, and at least one lower end biasing device arranged on a lower end side of the retaining member in the circumferential direction, one of the retaining member or the movable seal member includes a first convex portion protruding toward the other of the retaining member or the movable seal member along the radial direction, the other of the retaining member or the movable seal member includes a first concave portion with which the first convex portion can engage, and each of the first convex portion and the first concave portion is a sealing device provided between the upper end side biasing device arranged at the furthest lower end side in the circumferential direction and the lower end side biasing device arranged at the furthest upper end side, and having side surfaces extending along the radial direction and slidably facing each other.

2. The seal device according to claim 1, wherein the retaining member includes the first convex portion, and the movable seal member includes the first concave portion.

3. The seal device according to claim 1, wherein the retaining member includes the first recess, and the movable seal member includes the first protrusion.

4. A sealing device as claimed in any one of claims 1 to 3, wherein the retaining member includes a plurality of accommodating grooves which respectively accommodate the plurality of biasing devices, and a plurality of second convex portions which protrude radially inward in a circumferential range which includes each of the plurality of accommodating grooves in the circumferential direction, and the movable sealing member includes a plurality of second concave portions into which the plurality of second convex portions are respectively inserted.

5. A sealing device as described in claim 4, wherein each of the plurality of second recesses is provided with a second gap, which is a circumferential gap formed between the second recess and the second protrusion inserted into the second recess in the circumferential direction.

6. A sealing device as described in any one of claims 1 to 3, wherein when the side surfaces of the retaining member and the movable sealing member abut against each other, the upper end of the retaining member is located a distance D1 toward the upper end in the circumferential direction from the upper end of the movable sealing member, and when the side surfaces of the retaining member and the movable sealing member abut against each other, the lower end of the retaining member is located a distance D2 toward the lower end in the circumferential direction from the lower end of the movable sealing member.

7. The sealing device according to claim 6, wherein the distance D1 is greater than the distance D2.

8. A seal device according to any one of claims 1 to 3, wherein the at least one upper end biasing device is configured to have a greater biasing force than the at least one lower end biasing device.

9. A sealing device according to any one of claims 1 to 3, wherein each of the first convex portion and the first concave portion is provided in a circumferential range including a central position in the circumferential direction of the retaining member.

10. A seal system for sealing a first gap formed between a rotating member of a rotary machine and a stationary member arranged radially outside the rotating member, comprising a plurality of seal devices arranged side by side along the circumferential direction in the first gap, each of the plurality of seal devices being constituted by a seal device according to any one of claims 1 to 3.

11. A rotary machine comprising: the seal system according to claim 10; said rotating member; and said stationary member.

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