Rotating machine

Abstract

This rotating machine includes a rotary part, a stationary part surrounding the rotary part, and a seal device for reducing a leakage flow of fluid through a gap between the rotary part and the stationary part. The seal device includes: a seal member provided in a gap between the rotary part and the stationary part; and a first biasing member for biasing the seal member toward the outside in the radial direction of the rotating machine. The inner peripheral surface of the stationary part has a first groove extending along the circumferential direction of the rotating machine, and a second groove positioned on the upstream side of the first groove in the axial direction of the rotating machine and extending along the circumferential direction. A first support part capable of supporting the seal member is formed on a side surface of the first groove, and a second support part capable of supporting the seal member is formed on a side surface of the second groove.

Description

Rotating Machinery

[0001] This application claims priority to Japanese Patent Application No. 2023-170361, filed with the Japan Patent Office on September 29, 2023, the contents of which are incorporated herein by reference.

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

[0003] Patent document 1 describes a sealing device including an arcuate segment of a predetermined axial dimension carrying a plurality of axially spaced apart and circumferentially and radially extending seal teeth, and at least one circumferentially extending bristle row carried by the segment at a predetermined axial position along the segment and protruding beyond the radial dimension of the teeth, the bristles being held in a first flexible support strip slidably and removably supported in slots provided in the segment.

[0004] Japanese Patent Application Publication No. 11-201293

[0005] However, while widening the range in which the seal member is provided in the axial direction of the rotary machine can reduce fluid leakage through the gap between the rotating part and the stationary part, there is a concern that the seal member may bend due to pressure applied to the seal member, which may cause the seal member to come into contact with the rotor. In this regard, Patent Document 1 does not disclose any knowledge for reducing the risk of contact between the rotor and the seal member due to bending of the seal member.

[0006] In view of the above circumstances, at least one embodiment of the present disclosure aims to provide a rotary machine that can reduce the risk of contact between a seal member and a rotor while reducing the leakage flow of fluid through a gap between a rotating part and a stationary part.

[0007] In order to achieve the above-mentioned object, a rotary machine according to at least one embodiment of the present disclosure is a rotary machine comprising: a rotating portion; a stationary portion surrounding the rotating portion; and a sealing device for reducing leakage flow of fluid through a gap between the rotating portion and the stationary portion, wherein the sealing device includes a sealing member provided in the gap between the rotating portion and the stationary portion; and a first biasing member that biases the sealing member radially outward of the rotary machine, wherein an inner surface of the stationary portion is formed with a first groove extending along the circumferential direction of the rotary machine, and a second groove located upstream of the first groove in the axial direction of the rotary machine and extending along the circumferential direction, wherein a first support portion capable of supporting the sealing member is formed on a side surface of the first groove, and a second support portion capable of supporting the sealing member is formed on a side surface of the second groove.

[0008] According to at least one embodiment of the present disclosure, a rotary machine is provided that can reduce the risk of contact between a seal member and a rotor while reducing fluid leakage through a gap between a rotating part and a stationary part.

[0009] 1 is a partial schematic cross-sectional view perpendicular to the axial direction of a rotary machine 1A according to one embodiment. FIG. 1 is a schematic cross-sectional view of a sealing device 10A during start-up / shutdown operations and during shutdown of the rotary machine 1A, showing a cross section taken along A-A in FIG. 1. FIG. 1 is a schematic cross-sectional view of the sealing device 10A during load operation of the rotary machine 1A, showing a cross section taken along A-A in FIG. 1. FIG. 1 is a schematic cross-sectional view of the sealing device 10A during start-up / shutdown operations and during shutdown of the rotary machine 1A, showing a cross section taken along B-B in FIG. 1. FIG. 1 is a schematic cross-sectional view of the sealing device 10A during load operation of the rotary machine 1A, showing a cross section taken along B-B in FIG. 1. FIG. 1 is a partial schematic cross-sectional view perpendicular to the axial direction of a rotary machine 1B according to another embodiment. FIG. 4 is a schematic cross-sectional view of a sealing device 10B during start-up / shutdown operations and during shutdown of the rotary machine 1B, showing a cross section taken along C-C in FIG. 4. FIG. 4 is a schematic cross-sectional view of the sealing device 10B during load operation of the rotary machine 1B, showing a cross section taken along C-C in FIG. 4. Fig. 4 is a schematic cross-sectional view of the sealing device 10B during start-up and shutdown operations and when the rotary machine 1B is out of operation, and is a view showing a cross section taken along D-D in Fig. 4. Fig. 5 is a schematic cross-sectional view of the sealing device 10B during load operation of the rotary machine 1B, and is a view showing a cross section taken along D-D in Fig. 4. Fig. 6 is a view showing an example of a schematic cross section of the sealing device 10A during load operation of the rotary machine 1A.

[0010] Several embodiments of the present disclosure will be described below 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 invention. For example, 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 relative displacements with a tolerance or angle or distance to the extent that the same function is achieved. For example, expressions expressing the equality of things, such as "same," "equal," and "homogeneous," not only express strict equality, but also express tolerance or differences to the extent that the same function is achieved. For example, expressions expressing shapes such as a square or cylindrical shape not only express shapes such as a square or 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 achieved. On the other hand, the expressions "comprise," "include," "have," "includes," or "have" of one element are not exclusive expressions that exclude the presence of other elements.

[0011] (Configuration of Rotating Machine 1A) Fig. 1 is a partial schematic cross-sectional view perpendicular to the axial direction of a rotating machine 1A according to one embodiment. Figs. 2A and 2B are schematic cross-sectional views of a sealing device 10A provided in the rotating machine 1A, showing a cross section taken along line A-A in Fig. 1. Figs. 3A and 3B are schematic cross-sectional views of the sealing device 10A provided in the rotating machine 1A, showing a cross section taken along line B-B in Fig. 1. Here, Figs. 2A and 3A are views showing the sealing device 10A during start-up and shutdown operations and when the rotating machine 1A is out of operation. Figs. 2B and 3B are views showing the sealing device 10A during load operation of the rotating machine 1A.

[0012] A rotary machine 1A according to some embodiments is a fluid machine such as a turbine (such as a gas turbine or a steam turbine), a compressor, or a pump. As shown in FIGS. 1 to 3B , the rotary machine 1A according to one embodiment includes a rotating portion 2 (rotor) and a stationary portion 4 (not shown in FIG. 1 ) that is provided on the outer periphery of the rotating portion 2 and surrounds the rotating portion 2. The rotating portion 2 is supported by bearings (not shown) so as to be rotatable about a central axis O. The stationary portion 4 includes a casing that houses the rotating portion 2 and a stationary member supported by the casing. The stationary portion 4 may include a blade ring for supporting stationary blades, or a stationary member (such as a dummy ring or a retaining ring) for supporting a seal member or the like.

[0013] In the following, unless otherwise specified, "axial direction" means the axial direction of the rotating machine 1A (the direction of the central axis O), i.e., the axial direction of the rotating part 2; "radial direction" means the radial direction of the rotating machine 1A, i.e., the radial direction of the rotating part 2; and "circumferential direction" means the circumferential direction of the rotating machine 1A, i.e., the circumferential direction of the rotating part 2.

[0014] Between the rotating portion 2 and the stationary portion 4 in the radial direction, an annular gap g through which a fluid flows is formed. As shown in FIGS. 2A to 3B , the annular gap g includes a high-pressure portion 6, which is located upstream of the sealing device 10A in the axial direction and through which a relatively high-pressure fluid flows, and a low-pressure portion 8, which is located downstream of the sealing device 10A in the axial direction and through which a relatively low-pressure fluid (lower than the high-pressure portion 6) flows. The high-pressure portion 6 and the low-pressure portion 8 are positioned offset from each other in the axial direction. In the following description, the upstream side in the axial direction means the upstream side of the fluid flow in the gap g in the axial direction, i.e., closer to the high-pressure portion 6 in the axial direction, and the downstream side in the axial direction means the downstream side of the fluid flow in the gap g in the axial direction, i.e., closer to the low-pressure portion 8 in the axial direction.

[0015] A rotary machine 1A according to some embodiments includes a seal device 10A for reducing leakage of fluid through a gap g between a rotating part 2 and a stationary part 4. The seal device 10A will be described in more detail below.

[0016] 1 to 3B, the sealing device 10A includes a movable seal member 20 (seal member) provided between the rotating part 2 and the stationary part 4 in the radial direction of the rotary machine 1A, and a holding member 30 (first holding member) for supporting the movable seal member 20 so that it can move along the radial direction. In one embodiment, as shown in FIG. 1, the movable seal member 20 and the holding member 30 extend along the circumferential direction. That is, the movable seal member 20 and the holding member 30 may have a ring shape or an arc shape (a shape obtained by dividing a ring shape in the circumferential direction).

[0017] In some embodiments, as shown in Fig. 1, the seal device 10A may include a fixed seal member 40 that is provided adjacent to the movable seal member 20 in the circumferential direction. The fixed seal member 40 is configured to basically not move in the radial direction. In the exemplary embodiment shown in Fig. 1, the seal device 10A includes movable seal members 20 that are provided above and below the rotating unit 2 in the up-down direction (vertical direction), and multiple fixed seal members 40 that are provided on the sides of the rotating unit 2 so as to be adjacent to the ends of the movable seal members 20 in the circumferential direction.

[0018] 2A to 3B, the movable seal member 20 is provided between the high pressure section 6 and the low pressure section 8 in the axial direction of the rotary machine 1A. In the exemplary embodiment shown in Figures 2A to 3B, a plurality of seal fins 24 are provided on a surface 20a (inner peripheral surface) of the movable seal member 20 that faces the rotating section 2. In some embodiments, a plurality of seal fins may be provided on the outer peripheral surface 2a of the rotating section 2 (i.e., the surface that faces the movable seal member 20).

[0019] The movable seal member 20 has an outer peripheral surface 20b facing the stationary portion 4, and a gap 21 that allows communication with the high-pressure portion 6 is formed between the outer peripheral surface 20b and the stationary portion 4 in the radial direction. In other words, the pressure of the fluid from the high-pressure portion 6 acts on the outer peripheral surface 20b of the movable seal member 20.

[0020] The retaining member 30 is at least partially accommodated in a groove 5 (first groove) provided in the stationary portion 4 so as to extend along the circumferential direction. The groove 5 is recessed radially outward from the inner circumferential surface 4a of the stationary portion 4 and is formed by a pair of side surfaces 63, 64 and a bottom surface 65 connecting the pair of side surfaces 63, 64. Each of the pair of side surfaces 63, 64 is formed along a plane perpendicular to the axial direction and is arranged to face each other in the axial direction. The groove 5 may be provided in a casing (stationary portion 4) that accommodates the rotating portion 2 of the rotary machine 1A or a stationary member (stationary portion 4) supported by the casing. The groove 5 may be provided, for example, in a dummy ring (stationary portion 4) of a steam turbine or a retaining ring (stationary portion 4) of a gas turbine. In the exemplary embodiment shown in FIGS. 2A to 3B , the retaining member 30 includes a base portion 32 accommodated in the groove 5 and an inner protrusion 34 that protrudes radially inward from the base portion 32.

[0021] The axial length of the portion of the holding member 30 that is housed in the groove 5 (the axial length of the base 32 in the illustrated embodiment) is slightly shorter than the axial length of the groove 5. Therefore, with axial play between the groove 5 and the holding member 30, the holding member 30 is positioned in the axial direction by the groove 5.

[0022] The retaining member 30 may have, in at least a portion of its circumferential region (e.g., the portion shown in FIGS. 2A and 2B ), an abutting portion 36 that abuts against an axial protruding portion 7 that protrudes in the axial direction in the groove 5 of the stationary portion 4. The axial protruding portion 7 protrudes axially downstream from the upstream side surface 63 of a pair of side surfaces 63, 64 of the groove 5. The abutting portion 36 of the retaining member 30 is located radially outward of the axial protruding portion 7. A biasing member 42 may be provided in the groove 5 radially outward of the retaining member 30 and radially inward of the stationary portion 4 to bias the retaining member 30 radially inward. The retaining member 30 may be biased radially inward by the biasing member 42, and the abutting portion 36 may abut against the axial protruding portion 7 to restrict the radial position of the retaining member 30, thereby positioning the retaining member 30 radially.

[0023] In some embodiments, as shown in FIGS. 2A and 2B , for example, the seal device 10A includes a head portion 52 accommodated in the retaining member 30 and a shaft portion 54 extending radially and connecting the head portion 52 and the movable seal member 20. The movable seal member 20 is supported on the retaining member 30 so as to be movable radially via the head portion 52 and the shaft portion 54 connected to the movable seal member 20. The head portion 52 is accommodated inside an accommodation space 31 provided in the retaining member 30. The shaft portion 54 is provided to pass through a hole 33 provided in the retaining member 30 so as to communicate with the accommodation space 31. In the exemplary embodiment shown in FIGS. 2A and 2B , the seal device 10A includes a bolt portion 50, and the head portion 52 and the shaft portion 54 described above are part of the bolt portion 50. In some embodiments, the head portion 52 and the shaft portion 54 may be formed as separate members. The head portion 52 and / or the shaft portion 54 may include a pin.

[0024] Here, the axial length of the hole 33 is smaller than the diameter of the head 52 and larger than the diameter of the shank 54. Furthermore, the radial length of the accommodation space 31 is longer than the radial length of the head 52. Therefore, the head 52 and the shank 54 (bolt portion 50) can move radially within the accommodation space 31 without the head 52 coming out of the accommodation space 31, and the movable seal member 20 connected to the shank 54 (bolt portion 50) can move radially together with the head 52 and the shank 54 (bolt portion 50). As shown in FIGS. 2A and 2B , the shank 54 may have one end on which a thread 56 is formed and may be threaded into the threaded hole 26 provided in the movable seal member 20. In some embodiments, the shank 54 (e.g., a pin) may be connected to the movable seal member 20 by shrink fitting, welding, or the like.

[0025] In some embodiments, the head portion 52 and the shaft portion 54 (bolt portion 50) may be provided at each of a plurality of positions in the circumferential direction.

[0026] In some embodiments, the seal device 10A may include a biasing member 60 (first biasing member) configured to bias the movable seal member 20 radially outward relative to the retaining member 30 (see FIGS. 2A and 2B ). As shown in FIGS. 2A and 2B , the biasing member 60 may be provided between the radially inward facing surface 53 of the head 52 and the radially outward facing surface 37 of the inner wall surface that defines the accommodation space 31 of the retaining member 30. In the exemplary embodiment shown in FIGS. 2A and 2B , the biasing member 60 includes a plurality of disc springs 62.

[0027] In some embodiments, the above-described biasing member 60 may be provided at each of a plurality of positions in the circumferential direction.

[0028] 3A and 3B , in a position in the circumferential direction where the biasing member 60 is not provided or where the head 52 and the shank 54 (bolt portion 50) are not provided, the movable seal member 20 may be partially housed in the groove 5 of the stationary portion 4. In at least a partial region in the circumferential direction (for example, the portion shown in FIGS. 3A and 3B ), the movable seal member 20 may include a seal member main body 70 including an inner circumferential surface 20 a facing the outer circumferential surface 2 a of the rotating portion 2, a radial protruding portion 72 protruding radially outward from the outer circumferential surface 20 b of the seal member main body 70, and an axial protruding portion 74 (shoulder portion) protruding axially upstream from a side surface 73 of the radial protruding portion 72 on the upstream side in the axial direction.

[0029] The seal member main body 70 has a ring or arc shape (a shape obtained by dividing a ring shape circumferentially) that fits along the outer peripheral surface 2a of the rotating part 2. The radially outer end of the radial protruding part 72 and the axial protruding part 74 are housed in the groove 5. The radial protruding part 72 is located radially between the seal member main body 70 and the base 32 of the holding member 30. The axial protruding part 74 is located radially between the base 32 of the holding member 30 and the axial protruding part 7 of the stationary part 4, and engages (abuts) with the axial protruding part 7 when the movable seal member 20 is located radially inward (during loaded operation of the rotary machine 1A). The axial protruding part 7 of the stationary part 4 is located radially inward of the axial protruding part 74 of the movable seal member 20, and engages (abuts) with the axial protruding part 74 to support the axial protruding part 74 when the movable seal member 20 is located radially inward, thereby functioning as a first support part that supports the movable seal member 20.

[0030] As shown in FIGS. 2A to 3B , a groove 9 (second groove) is formed in the inner circumferential surface 4a of the stationary portion 4, located upstream of the groove 5 in the axial direction and extending circumferentially. The groove 9 is recessed radially outward from the inner circumferential surface 4a of the stationary portion 4 and is formed by a pair of side surfaces 66, 67 and a bottom surface 68 connecting the pair of side surfaces 66, 67. The stationary portion 4 includes a partition wall portion 11 that protrudes radially inward from the inner circumferential surface 4a to separate the groove 5 and the groove 9 in the axial direction, and the partition wall portion 11 extends circumferentially. Each of the pair of side surfaces 66, 67 is formed along a plane perpendicular to the axial direction and is arranged to face each other in the axial direction. The groove 5 is formed with an axial protrusion portion 69 that protrudes axially downstream from the upstream side surface 66 of the pair of side surfaces 66, 67 of the groove 5. The groove 9 may be provided in a casing (stationary portion 4) that houses the rotating portion 2 of the rotary machine 1A, or in a stationary member (stationary portion 4) supported by the casing. The groove 9 may be provided in, for example, a dummy ring (stationary portion 4) of a steam turbine, or a retaining ring (stationary portion 4) of a gas turbine.

[0031] In addition, in at least some regions in the circumferential direction (for example, the portions shown in Figures 2A and 2B and the portions shown in Figures 3A and 3B), the movable sealing member 20 is located upstream of the radial protrusion 72 in the axial direction, and includes a radial protrusion 75 that protrudes radially outward from the outer peripheral surface 20b of the sealing member main body 70, and an axial protrusion 77 that protrudes upstream in the axial direction from the axially upstream side surface 76 of the radial protrusion 75.

[0032] The radially outer end of the radial protrusion 75 and the axial protrusion 77 are housed in the groove 9. The radial protrusion 75 is located between the seal member main body 70 and a bottom surface 68 of the groove 9 in the radial direction, and gaps are provided between each of the side surfaces 66, 67 of the groove 9 and the radial protrusion 75. The axial protrusion 77 is located between the axial protrusion 69 and the bottom surface 68 of the groove 9 in the radial direction, and engages with (abuts against) the axial protrusion 69 when the movable seal member 20 is located radially inside (during loaded operation of the rotary machine 1A). The axial protrusion 69 of the stationary part 4 is located radially inside the axial protrusion 77 of the movable seal member 20, and engages with (abuts against) the axial protrusion 77 to support the axial protrusion 77, thereby functioning as a second support part that supports the movable seal member 20.

[0033] Here, a brief description of the operation of the above-described sealing device 10A will be given. During startup and shutdown operations and when the rotary machine 1A is not operating, the movable seal member 20 is biased radially outward by the biasing member 60, maintaining a large clearance between the rotating part 2 and the movable seal member 20 (or the seal fins 24) (see FIGS. 2A and 3A ). When the load on the rotary machine 1A increases, the pressure difference between the high-pressure section 6 and the low-pressure section 8 increases, resulting in a difference between the pressure acting on the outer circumferential surface 20b of the movable seal member 20 (the pressure of the high-pressure fluid in the high-pressure section 6) and the pressure acting on the inner circumferential surface 20a (which decreases from the high-pressure side to the low-pressure side). When this pressure difference causes a radially inward force acting on the movable seal member 20 to overcome the radially outward biasing force of the biasing member 60, the movable seal member 20 moves to a radially inward position, reducing the clearance between the rotating part 2 and the movable seal member 20 (or the seal fins 24) (see FIGS. 2B and 3B ). During load operation of the rotary machine 1A (such as during rated load operation), the pressure of the high-pressure fluid in the high-pressure section 6 continues to act on the outer surface 20b of the movable seal member 20 (more specifically, the range from the upstream end of the outer surface 20b to the sliding surface 22 described below), and the above-mentioned pressure difference is maintained, so that the clearance between the rotating section 2 and the movable seal member 20 (or the seal fin 24) remains small (see Figures 2B and 3B).

[0034] 2A to 3B, for example, the radial protrusion 72 of the movable seal member 20 is adjacent to the inner protrusion 34 of the holding member 30 in the axial direction and has a sliding surface 22 that is slidable against the inner protrusion 34. The inner protrusion 34 has an opposing surface 35 that faces the sliding surface 22 of the movable seal member 20 in the axial direction. In other words, the sliding surface 22 of the movable seal member 20 and the opposing surface 35 of the inner protrusion 34 are slidable against each other.

[0035] 2A to 3B, the inner protrusion 34 of the holding member 30 is located axially closer to the low-pressure section 8 than the sliding surface 22 of the movable seal member 20 (i.e., the sliding surface 22 of the movable seal member 20 is located axially closer to the high-pressure section 6 than the inner protrusion 34). Therefore, during operation of the rotary machine 1A, a force is applied to the movable seal member 20 in the axial direction from the high-pressure section 6 side to the low-pressure section 8 side due to the pressure difference between the high-pressure section 6 and the low-pressure section 8, and the movable seal member 20 and the holding member 30 slide against each other with the movable seal member 20 pressed against the inner protrusion 34 of the holding member 30.

[0036] In conventional sealing devices (i.e., sealing devices that do not include a retaining member) in which a movable seal member is housed in a groove in a stationary portion of a rotary machine (e.g., a stationary member such as a dummy ring or a retaining ring), sliding occurs between the seal member and the stationary portion (the stationary portion having a groove that houses the seal member) as the movable seal member moves radially. Repeated sliding can cause wear and other issues on the sliding surfaces of the seal member and the stationary portion, resulting in a change in the condition of the sliding surfaces (e.g., coefficient of friction) from their intended state. Such changes in the sliding surfaces can cause the movable seal member to operate unpredictably, such as not moving at the intended timing, resulting in unstable operation of the sealing device. This can result in reduced efficiency of the rotary machine and an increased risk of contact between the seal member and the rotating portion. While replacing worn parts can maintain the intended condition of the sliding surfaces, the worn parts (e.g., dummy rings or retaining rings) are large components that constitute the stationary portion of the rotary machine, and such large components may not be easily replaced due to cost and other factors.

[0037] In this regard, in the above-described embodiment, the inner protrusion 34 of the retaining member 30, which is housed in the groove 5 provided in the stationary portion 4, and the sliding surface 22 of the movable seal member 20, which is supported by the retaining member 30 so as to be radially movable, are adjacent to each other in the axial direction. Therefore, when the movable seal member 20 moves radially, the sliding surface 22 of the movable seal member 20 and the inner protrusion 34 of the retaining member 30 slide against each other. Therefore, if wear occurs on the sliding portions (the sliding surface 22 of the movable seal member 20 and the inner protrusion 34 of the retaining member 30), the surfaces of the sliding portions can be maintained in a desired state (e.g., a state having a desired coefficient of friction) by replacing the retaining member 30 and / or the movable seal member 20. Since the surfaces of the sliding portions can be easily maintained in a desired state, it is easy to maintain a state in which the movable seal member 20 operates stably in the rotary machine 1A. In other words, it is easy to maintain stable operation of the sealing device 10A in the rotary machine 1A.

[0038] In the above-described embodiment, the movable seal member 20 is urged by the urging member 60 radially outward relative to the retaining member 30 housed in the groove 5 of the stationary portion 4. In this manner, the urging member 60 applies a radially outward force to the movable seal member 20, allowing the movable seal member 20 to move smoothly along the radial direction in accordance with the operating state of the rotary machine 1A.

[0039] Furthermore, in the above-described embodiment, the movable seal member 20 is supported on the holding member 30 via the head 52 and the shank 54 (bolt portion) 50 so as to be movable in the radial direction, and a radially outward force is applied to the movable seal member 20 via the head 52 and the shank 54 (bolt portion 50) by the biasing member 60 provided between the head 52 and the inner wall surface (surface 37) of the holding member 30. In this way, with a simple configuration using the head 52 and the shank 54 (bolt portion 50), it is possible to apply a radially outward biasing force to the movable seal member 20 while supporting the movable seal member 20 so as to be movable along the radial direction.

[0040] Furthermore, in conventional sealing devices (i.e., sealing devices that do not include a retaining member), a biasing member for biasing the movable seal member radially outward is provided between the movable seal member and the stationary member in the radial direction. Therefore, when the sealing device is installed in a rotary machine, the preload (radial force) applied to the biasing member can sometimes prevent the movable seal member from being inserted circumferentially into the groove.

[0041] In this regard, in the above-described embodiment, the movable seal member 20 is supported by the holding member 30, and the biasing member 60 for biasing the movable seal member 20 radially outward is housed in the holding member 30. Therefore, with the movable seal member 20 and the biasing member 60 assembled to the holding member 30, the holding member 30 can be inserted circumferentially into the groove 5 of the stationary portion 4, thereby installing the seal device 10A including the movable seal member 20 in the rotary machine 1A. Therefore, even when a relatively large preload is applied to the biasing member 60, the preload does not hinder the insertion of the seal device 10A into the groove, and the seal device 10A can be smoothly installed in the rotary machine 1A.

[0042] In the above-described embodiment, the inner circumferential surface 4 a of the stationary portion 4 is formed with a groove 5 extending in the circumferential direction of the rotary machine 1A and a groove 9 located upstream of the groove 5 in the axial direction and extending in the circumferential direction. The groove 5 has an axial protruding portion 7 (first support portion) formed on a side surface 63 thereof that can support the movable seal member 20, and the groove 9 has an axial protruding portion 69 (second support portion) formed on a side surface 66 thereof that can support the movable seal member 20. Therefore, compared to, for example, a case where the stationary portion 4 does not have a groove 9 and the movable seal member 20 is cantilever-supported only by the axial protruding portion 7, the axial protruding portion 7 and the axial protruding portion 69 can support the movable seal member 20 at different positions in the axial direction. Therefore, bending deformation of the movable seal member 20 (e.g., deformation in which the upstream end of the movable seal member 20 bends radially inward as indicated by arrow F in FIG. 2B ) can be suppressed. Furthermore, compared to, for example, a case where separate seal members are provided in the grooves 5 and 9, the number of parts can be reduced. Therefore, with a small number of parts, it is possible to reduce the leakage flow of fluid through the gap g between the rotating part 2 and the stationary part 4, while suppressing the bending deformation of the movable sealing member 20 and reducing the risk of contact between the movable sealing member 20 and the rotating part 2.

[0043] (Modification) Fig. 4 is a partial schematic cross-sectional view perpendicular to the axial direction of a rotary machine 1B according to another embodiment. Figs. 5A and 5B are schematic cross-sectional views of a seal device 10B provided in the rotary machine 1B, showing a cross section taken along line CC in Fig. 4. Figs. 6A and 6B are schematic cross-sectional views of the seal device 10B provided in the rotary machine 1B, showing a cross section taken along line DD in Fig. 4. Here, Figs. 5A and 6A are views showing the seal device 10B during start-up and shutdown operations and when the rotary machine 1B is out of operation. Figs. 5B and 6B are views showing the seal device 10B during load operation of the rotary machine 1B.

[0044] 4 to 6B, the same reference numerals as those in the rotary machine 1A described above indicate the same components as those in the rotary machine 1A unless otherwise specified, and the description thereof will be omitted. In the rotary machine 1B, the configuration of a seal device 10B differs from that of the seal device 10A described above. Specifically, as shown in FIGS. 5A to 6B, the seal device 10B differs from the seal device 10A in that it includes a retaining member 80 and a biasing member 94 housed in the groove 9.

[0045] In the following, unless otherwise specified, "axial direction" means the axial direction of the rotating machine 1B (the direction of the central axis O), i.e., the axial direction of the rotating part 2; "radial direction" means the radial direction of the rotating machine 1B, i.e., the radial direction of the rotating part 2; and "circumferential direction" means the circumferential direction of the rotating machine 1B, i.e., the circumferential direction of the rotating part 2.

[0046] The retaining member 80 is at least partially accommodated in a groove 9 (second groove) provided in the stationary portion 4 so as to extend along the circumferential direction. The groove 9 is recessed radially outward from the inner circumferential surface 4a of the stationary portion 4 and is formed by a pair of side surfaces 66, 67 and a bottom surface 68 connecting the pair of side surfaces 66, 67. Each of the pair of side surfaces 66, 67 is formed along a plane perpendicular to the axial direction and is disposed so as to face each other in the axial direction. In the exemplary embodiment shown in FIGS. 2A to 3B , the retaining member 80 includes a base 82 accommodated in the groove 9 and an inner protrusion 83 protruding radially inward from the base 82.

[0047] The axial length of the portion of the holding member 80 that is housed in the groove 9 (the axial length of the base 82 in the illustrated embodiment) is slightly shorter than the axial length of the groove 9. Therefore, with axial play between the groove 9 and the holding member 80, the holding member 80 is positioned in the axial direction by the groove 9.

[0048] The retaining member 80 may have, in at least a portion of its circumferential region (e.g., the portion shown in FIGS. 5A and 5B ), an abutting portion 85 that abuts against the axial protruding portion 69 that protrudes in the axial direction in the groove 9 of the stationary portion 4. The axial protruding portion 69 protrudes axially downstream from the upstream side surface 66 of the pair of side surfaces 66, 67 of the groove 9. The abutting portion 85 of the retaining member 80 is located radially outward of the axial protruding portion 69. Within the groove 9, a biasing member 86 may be provided radially outward of the retaining member 80 and radially inward of the stationary portion 4 to bias the retaining member 80 radially inward. The retaining member 80 may be biased radially inward by the biasing member 86, and the abutting portion 85 may abut against the axial protruding portion 69 to restrict the radial position of the retaining member 80, thereby positioning the retaining member 80 radially.

[0049] In some embodiments, as shown in FIGS. 5A and 5B , for example, the seal device 10B includes a head portion 87 accommodated in the retaining member 80 and a shaft portion 88 extending radially and connecting the head portion 87 to the movable seal member 20. The movable seal member 20 is supported on the retaining member 80 so as to be movable radially via the head portion 87 and the shaft portion 88 connected to the movable seal member 20. The head portion 87 is accommodated inside an accommodation space 89 provided in the retaining member 80. The shaft portion 88 is provided to pass through a hole 90 provided in the retaining member 80 so as to communicate with the accommodation space 89. In the exemplary embodiment shown in FIGS. 5A and 5B , the seal device 10B includes a bolt portion 91, and the head portion 87 and the shaft portion 88 described above are part of the bolt portion 91. In some embodiments, the head portion 87 and the shaft portion 88 may be formed as separate members. The head portion 87 and / or the shaft portion 88 may include a pin.

[0050] Here, the axial length of the hole 90 is smaller than the diameter of the head 87 and larger than the diameter of the shank 88. Furthermore, the radial length of the accommodation space 89 is longer than the radial length of the head 87. Therefore, the head 87 and the shank 88 (bolt portion 91) can move radially within the accommodation space 89 without the head 87 coming out of the accommodation space 89, and the movable seal member 20 connected to the shank 88 (bolt portion 91) can move radially together with the head 87 and the shank 88 (bolt portion 91). As shown in FIGS. 5A and 5B , the shank 88 may have one end on which a thread 92 is formed and which is adapted to be threaded into a threaded hole 93 provided in the movable seal member 20. In some embodiments, the shank 88 (e.g., a pin) may be connected to the movable seal member 20 by shrink fitting, welding, or the like.

[0051] In some embodiments, the head portion 87 and the shaft portion 88 (bolt portion 91) may be provided at each of a plurality of positions in the circumferential direction.

[0052] In some embodiments, the seal device 10B may include a biasing member 94 (second biasing member) configured to bias the movable seal member 20 radially outward relative to the retaining member 80 (see FIGS. 5A and 5B ). As shown in FIGS. 5A and 5B , the biasing member 94 may be provided between a surface 95 facing radially inward of the head 87 and a surface 96 facing radially outward of the inner wall surface that defines the accommodation space 89 of the retaining member 80. In the exemplary embodiment shown in FIGS. 5A and 5B , the biasing member 94 includes a plurality of disc springs 97.

[0053] In some embodiments, the above-described biasing member 94 may be provided at each of a plurality of positions in the circumferential direction.

[0054] In addition, at positions in the circumferential direction where the biasing member 94 is not provided or where the head 87 and the shaft 88 (bolt portion 91) are not provided, the movable sealing member 20 may be partially accommodated in the groove 9 of the stationary portion 4, as shown in Figures 6A and 6B, for example.

[0055] In the sealing device 10B, the movable sealing member 20 is located upstream of the radial protrusion 72 in the axial direction in at least a portion of the circumferential region (for example, the portion shown in Figures 6A and 6B), and includes a radial protrusion 75 that protrudes radially outward from the outer peripheral surface 20b of the sealing member main body 70, and an axial protrusion 77 that protrudes upstream in the axial direction from the axially upstream side surface 76 of the radial protrusion 75.

[0056] The radially outer end of the radial protrusion 75 and the axial protrusion 77 are housed in the groove 9. The radial protrusion 75 is located between the seal member main body 70 and a bottom surface 68 of the groove 9 in the radial direction, and gaps are provided between each of the side surfaces 66, 67 of the groove 9 and the radial protrusion 75. The axial protrusion 77 is located between the axial protrusion 69 and the bottom surface 68 of the groove 9 in the radial direction, and engages with (abuts against) the axial protrusion 69 when the movable seal member 20 is located radially inside (during loaded operation of the rotary machine 1A). The axial protrusion 69 of the stationary part 4 is located radially inside the axial protrusion 77 of the movable seal member 20, and engages with and supports the axial protrusion 77, thereby functioning as a second support part that supports the movable seal member 20.

[0057] Here, a brief description will be given of the operation of the above-described sealing device 10B. During start-up / shutdown operations or when the rotary machine 1B is stopped, the movable seal member 20 is urged radially outward by the urging member 60 and the urging member 94, maintaining a large clearance between the rotating part 2 and the movable seal member 20 (or the seal fins 24) (see FIGS. 5A and 6A ). When the load on the rotary machine 1B increases, the pressure difference between the high-pressure section 6 and the low-pressure section 8 increases, resulting in a difference between the pressure acting on the outer peripheral surface 20b of the movable seal member 20 (the pressure of the high-pressure fluid in the high-pressure section 6) and the pressure acting on the inner peripheral surface 20a (the pressure decreasing from the high-pressure side to the low-pressure side). When the radially inward force acting on the movable seal member 20 due to this pressure difference overcomes the radially outward biasing forces of the biasing members 60 and 94, the movable seal member 20 moves to a radially inward position, and the clearance between the rotating part 2 and the movable seal member 20 (or the seal fins 24) becomes small (see FIGS. 5B and 6B ). During load operation of the rotary machine 1B (such as during rated load operation), the pressure of the high-pressure fluid in the high-pressure section 6 continues to act on the outer peripheral surface 20 b of the movable seal member 20 (more specifically, the range from the upstream end of the outer peripheral surface 20 b to the sliding surface 22), maintaining the above-mentioned pressure difference, and therefore the clearance between the rotating part 2 and the movable seal member 20 (or the seal fins 24) remains small (see FIGS. 5B and 6B ).

[0058] In some embodiments, as shown in FIGS. 5A to 6B , for example, the radial protrusion 75 of the movable seal member 20 is disposed so as to face the inner protrusion 83 of the holding member 80 in the axial direction. An axial gap is provided between the radial protrusion 75 and the inner protrusion 83 over at least a portion of the circumferential direction. That is, a side surface 98 on the axial downstream side of the radial protrusion 75 and a side surface 99 on the axial upstream side of the inner protrusion 83 face each other in the axial direction, and an axial gap is provided between the side surfaces 98 and 99 over at least a portion of the circumferential direction. Therefore, the fluid in the high-pressure section 6 passes through the gap between the radial protrusion 75 and the inner protrusion 83 and is supplied to the gap between the seal member 20 and the stationary section 4 on the groove 5 side and the gap between the seal member 20 and the holding member 30. This causes the pressure of the fluid in the high-pressure section 6 to act on the range from the upstream end of the outer circumferential surface 20b of the seal member 20 to the sliding surface 22, thereby moving the movable seal member 20 in the radial direction as described above.

[0059] 4 to 6B, a radially outward force is applied to the seal member 20 from the biasing member 60 and the biasing member 94, so that the radially outward force acting on the seal member 20 can be made greater than when the biasing member 94 is not provided (see FIGS. 2A to 3B). Therefore, the seal device 10B can be suitably applied to a portion of the gap between the stationary part 4 and the rotating part 2 where the pressure difference between the upstream side and the downstream side of the seal member 20 becomes large.

[0060] 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.

[0061] 7 , the stationary portion 4 of the above-described rotary machine 1A or 1B may not be provided with a partition wall portion 11 separating the groove 5 and the groove 9 in a partial range in the circumferential direction. In other words, the groove 5 and the groove 9 may be connected in the axial direction in a partial range in the circumferential direction.

[0062] The contents described in each of the above embodiments can be understood, for example, as follows.

[0063] (1) A rotary machine according to at least one embodiment of the present disclosure (e.g., the above-described rotary machines 1A and 1B) is a rotary machine including: a rotating portion (e.g., the above-described rotating portion 2); a stationary portion (e.g., the above-described stationary portion 4) surrounding the rotating portion; and a sealing device (e.g., the above-described sealing devices 10A and 10B) for reducing leakage of fluid through a gap between the rotating portion and the stationary portion, wherein the sealing device includes: a sealing member (e.g., the above-described movable sealing member 20) provided in the gap between the rotating portion and the stationary portion; and a first biasing member (e.g., the above-described biasing member 60) that biases the sealing member toward an outer side in a radial direction of the rotary machine, wherein an inner peripheral surface (e.g., the above-described inner peripheral surface 4a) of the stationary portion is formed with a first groove (e.g., the above-described groove 5) extending along the circumferential direction of the rotary machine; and a second groove (e.g., the above-described groove 9) located upstream of the first groove in the axial direction of the rotary machine and extending along the circumferential direction, A first support portion (e.g., the above-mentioned axial protrusion 7) capable of supporting the seal member is formed on the side surface of the first groove, and a second support portion (e.g., the above-mentioned axial protrusion 69) capable of supporting the seal member is formed on the side surface of the second groove.

[0064] According to the rotating machine described in (1) above, the inner peripheral surface of the stationary portion is formed with a groove extending circumferentially of the rotating machine and a groove located upstream of the groove in the axial direction of the rotating machine and extending circumferentially. A first support portion capable of supporting a seal member is formed on a side surface of the first groove, and a second support portion capable of supporting the seal member is formed on a side surface of the second groove. Therefore, compared to, for example, a case where the stationary portion does not have a second groove and the seal member is cantilevered only by the first support portion, the first support portion and the second support portion can support the seal member at different positions in the axial direction, thereby suppressing deflection of the seal member. Furthermore, compared to, for example, a case where separate seal members are provided in the first groove and the second groove, the number of parts can be reduced. Therefore, with a reduced number of parts, it is possible to reduce fluid leakage through the gap between the rotating portion and the stationary portion while suppressing deflection of the seal member and reducing the risk of contact between the movable seal member and the rotating portion.

[0065] (2) In some embodiments, in the rotary machine described in (1) above, the first support portion protrudes from the upstream side surface of the first groove in the axial direction toward the downstream side in the axial direction, and the second support portion protrudes from the upstream side surface of the second groove in the axial direction toward the downstream side in the axial direction.

[0066] According to the rotary machine described in (2) above, the first support portion protruding from the axially upstream side surface of the first groove toward the axially downstream side and the second support portion protruding from the axially upstream side surface of the second groove toward the axially downstream side allow the first support portion and the second support portion to support the seal member at different axial positions, thereby suppressing deflection of the seal member. Therefore, with a small number of parts, it is possible to reduce fluid leakage through the gap between the rotating part and the stationary part, while suppressing deflection of the seal member and reducing the risk of contact between the rotating part and the movable seal member.

[0067] (3) In some embodiments, in the rotary machine described in (1) or (2) above, the seal member includes: a seal member main body (e.g., the above-described seal member main body 70) provided along the circumferential direction so as to face an outer circumferential surface of the rotating part; a first radial protrusion (e.g., the above-described radial protrusion 72) protruding outward in the radial direction from the outer circumferential surface of the seal member main body; a first axial protrusion (e.g., the above-described axial protrusion 74) protruding upstream in the axial direction from a side surface of the first radial protrusion on an upstream side in the axial direction, a second radial protrusion (e.g., the above-described radial protrusion 75) located upstream of the first radial protrusion in the axial direction and protruding outward in the radial direction from the outer circumferential surface of the seal member main body; and a second axial protrusion (e.g., the above-described axial protrusion 77) protruding upstream in the axial direction from a side surface of the second radial protrusion on an upstream side in the axial direction, The second support portion is located inside the second axial protruding portion in the radial direction.

[0068] According to the rotary machine described in (3) above, the first axial protruding portion is supported by the first support portion that protrudes from the axially upstream side surface of the first groove toward the axially downstream side, and the second axial protruding portion is supported by the second support portion that protrudes from the axially upstream side surface of the second groove toward the axially downstream side, thereby suppressing deflection of the seal member. Therefore, with a small number of parts, it is possible to reduce fluid leakage through the gap between the rotating part and the stationary part, while suppressing deflection of the seal member and reducing the risk of contact between the movable seal member and the rotating part.

[0069] (4) In some embodiments, in the rotary machine described in (3) above, the sealing device includes a first retaining member (e.g., the above-mentioned retaining member 30) for supporting the sealing member so that it can move along the radial direction, and the first retaining member has a base (e.g., the above-mentioned base 32) that is accommodated in the first groove, and an inner protrusion (e.g., the above-mentioned inner protrusion 34) that protrudes radially inward from the base, and the first radial protrusion has a sliding surface (e.g., the above-mentioned sliding surface 22) that is adjacent to the inner protrusion in the axial direction and can slide against the inner protrusion.

[0070] According to the rotary machine described in (4) above, the inner protrusion of the first holding member, which is housed in the first groove provided in the stationary portion, and the sliding surface of the seal member, which is supported by the first holding member so as to be radially movable, are adjacent to each other in the axial direction. Therefore, when the seal member moves along the radial direction, the sliding surface of the seal member and the inner protrusion of the first holding member slide against each other. Therefore, if wear occurs on the sliding portion (the sliding surface of the seal member and the inner protrusion of the first holding member), the surface of the sliding portion can be maintained in a desired condition by replacing the first holding member and / or the seal member. Since the surface of the sliding portion can be easily maintained in a desired condition, it is easy to maintain a stable operating state of the seal member in the rotary machine. In other words, it is easy to maintain stable operation of the sealing device in the rotary machine.

[0071] (5) In some embodiments, in the rotary machine described in (4) above, the first biasing member is housed in the first holding member and configured to bias the seal member outward in the radial direction.

[0072] According to the rotary machine described in (5) above, the first biasing member applies a radially outward force to the seal member, allowing the seal member to move smoothly along the radial direction depending on the operating state of the rotary machine.

[0073] (6) In some embodiments, in the rotary machine described in (5) above, the sealing device includes a second retaining member (e.g., the above-mentioned retaining member 80) that is at least partially accommodated in the second groove and supports the sealing member so that it can move along the radial direction, and a second biasing member (e.g., the above-mentioned biasing member 94) that is accommodated in the second retaining member and is configured to bias the sealing member radially outward, wherein the second retaining member has a base (e.g., the above-mentioned base 82) that is accommodated in the second groove, and an inner protrusion (e.g., the above-mentioned inner protrusion 83) that protrudes radially inward from the base, and a gap is provided between the second radial protrusion and the inner protrusion of the second retaining member over at least a portion of the circumferential range.

[0074] According to the rotary machine described in (6) above, since the first biasing member and the second biasing member apply a radially outward force to the seal member, the radially outward force acting on the seal member can be made larger than when the second biasing member is not provided. Therefore, the sealing device can be applied to a portion where the pressure difference between the upstream side and the downstream side of the seal member in the gap between the stationary part and the rotating part becomes large during operation of the rotary machine (for example, during rated operation of the rotary machine, etc.).

[0075] 1A, 1B Rotating machine 2 Rotating portion 2a, 20b Outer peripheral surface 4 Stationary portion 4a, 20a Inner peripheral surface 5, 9 Groove 6 High-pressure portion 7, 69, 74, 77 Axial protruding portion 8 Low-pressure portion 10, 10A, 10B Sealing device 20 Movable seal member 37, 53, 95, 96 Surface 20a Inner peripheral surface 21, g Gap 22 Sliding surface 24 Seal fin 26, 93 Screw hole 30, 80 Retaining member 31, 89 Accommodation space 32, 82 Base 33, 90 Hole 34, 83 Inner protruding portion 35 Opposing surface 36, 85 Abutting portion 40 Fixed seal member 42, 60, 86, 94 Biasing member 50, 91 Bolt portion 52, 87 Head 54, 88 Shaft portion 56, 92 Screw 62, 97 Disc spring 63, 64, 66, 67, 73, 76, 98, 99 Side surface 65, 68 Bottom surface 70 Seal member main body portion 72, 75 Radial protrusion portion F Arrow O Central axis

Claims

1. A rotary machine comprising: a rotating part; a stationary part surrounding the rotating part; and a sealing device for reducing leakage flow of fluid through a gap between the rotating part and the stationary part, wherein the sealing device includes a sealing member provided in the gap between the rotating part and the stationary part; and a first biasing member for biasing the sealing member toward the outside in the radial direction of the rotary machine, wherein an inner surface of the stationary part is formed with a first groove extending along the circumferential direction of the rotary machine, and a second groove located upstream of the first groove in the axial direction of the rotary machine and extending along the circumferential direction, wherein a first support portion capable of supporting the sealing member is formed on a side surface of the first groove, and a second support portion capable of supporting the sealing member is formed on a side surface of the second groove.

2. A rotating machine as described in claim 1, wherein the first support portion protrudes from a side surface of the first groove on the upstream side in the axial direction toward the downstream side in the axial direction, and the second support portion protrudes from a side surface of the second groove on the upstream side in the axial direction toward the downstream side in the axial direction.

3. The rotating machine of claim 2, wherein the sealing member includes: a sealing member main body provided along the circumferential direction so as to face an outer peripheral surface of the rotating part; a first radial protrusion protruding radially outward from the outer peripheral surface of the sealing member main body; a first axial protrusion protruding upstream in the axial direction from an upstream side surface of the first radial protrusion; a second radial protrusion located upstream of the first radial protrusion in the axial direction and protruding radially outward from the outer peripheral surface of the sealing member main body; and a second axial protrusion protruding upstream in the axial direction from an upstream side surface of the second radial protrusion; and wherein the first support portion is located inside the first axial protrusion in the radial direction, and the second support portion is located inside the second axial protrusion in the radial direction.

4. A rotary machine as described in claim 3, wherein the sealing device includes a first retaining member for supporting the sealing member movably along the radial direction, the first retaining member having a base received in the first groove and an inner protrusion protruding from the base toward the inside in the radial direction, and the first radial protrusion having a sliding surface adjacent to the inner protrusion in the axial direction and capable of sliding against the inner protrusion.

5. A rotary machine according to claim 4, wherein the first biasing member is housed in the first holding member and configured to bias the seal member outward in the radial direction.

6. A rotary machine as described in claim 5, wherein the sealing device includes a second retaining member that is at least partially accommodated in the second groove and supports the sealing member movably along the radial direction, and a second biasing member that is accommodated in the second retaining member and configured to bias the sealing member outward in the radial direction, wherein the second retaining member has a base that is accommodated in the second groove and an inner protrusion that protrudes from the base toward the inside in the radial direction, and a gap is provided between the second radial protrusion and the inner protrusion of the second retaining member over at least a portion of the circumferential range.

Images