Sealing device and rotating machine

Abstract

This sealing device for sealing a first gap formed between a rotating member of a rotating machine and a stationary member disposed on an outer side of the rotating member in a radial direction comprises: a movable sealing member provided in the first gap; a holding member for supporting the movable sealing member arranged on an inner side in the radial direction such that the movable sealing member can move in the radial direction, the holding member including a base part accommodated in a groove provided along a circumferential direction in the stationary member; a biasing device including a biasing member for biasing the movable sealing member to the radially outer side along the radial direction with respect to the holding member; and an accommodation member which accommodates the biasing device and a portion of which is accommodated in the holding member, the accommodation member having, inward of the base part in the radial direction, an abutting surface on which the biasing member arranged on the radially outer side abuts.

Description

Seal device and rotating machine

[0001] This application claims priority to Japanese Patent Application No. 2024-114861, filed on July 18, 2024, 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] International Publication No. 2023 / 157519

[0006] In the sealing device described in Patent Document 1, a biasing device for exerting a biasing force on a movable sealing member, such as an elastic member, is housed inside a holding member that holds the movable sealing member so that the member can move radially. In such a sealing device, the radial length required for the elastic member to exert a biasing force is large, so the radial dimension of the holding member that houses the elastic member, etc., is large, and the groove that can accommodate the holding member is also large. Therefore, there is a risk that the sealing device cannot be installed in a shallow groove, such as a groove that houses a conventional fixed labyrinth seal. Furthermore, there is a risk that the assembly of the sealing device will be impaired when the sealing device is modified to be installed in a shallow groove.

[0007] In view of the above circumstances, at least one embodiment of the present disclosure aims to provide a sealing device that can be installed without compromising assembly even when the groove provided in the stationary member of the rotary machine is shallow, and a rotary machine equipped with the sealing device.

[0008] A sealing device according to at least one embodiment of the present disclosure is a sealing device 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 movable sealing member arranged in the first gap; a retaining member for supporting the movable sealing member arranged radially inside so that it can move along the radial direction, the retaining member including at least a base that is accommodated in a groove arranged circumferentially on the stationary member; at least one biasing device including a biasing member for biasing the movable sealing member radially outward relative to the retaining member along the radial direction; and at least one housing member that accommodates the biasing device and is partially accommodated in the holding member, the at least one housing member having an abutment surface that is radially inside the base and against which the biasing member arranged radially outside abuts.

[0009] A rotary machine according to at least one embodiment of the present disclosure includes: the sealing device; the rotating member; and the stationary member.

[0010] According to at least one embodiment of the present disclosure, a sealing device that can be installed without compromising assembly even when the groove provided in the stationary member of the rotary machine is shallow, and a rotary machine equipped with the sealing device are provided.

[0011] FIG. 7 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. 8 is a schematic cross-sectional view along the axial direction of a sealing device according to an embodiment of the present disclosure. FIG. 9 is a schematic cross-sectional view of a sealing device according to an embodiment of the present disclosure, viewed from one side in the axial direction. FIG. 10 is a schematic cross-sectional view of a sealing device according to an embodiment of the present disclosure, viewed from the outside in the radial direction. FIG. 11 is a schematic perspective view of a sealing device according to an embodiment of the present disclosure. FIG. 12 is a schematic view of an engagement portion of a housing member and a movable seal member of the sealing device shown in FIG. 6, viewed from the outside in the radial direction. FIG. 13 is a schematic perspective view of a sealing device according to an embodiment of the present disclosure. FIG. 14 is a schematic view of an engagement portion of a housing member and a movable seal member of a sealing device according to an embodiment of the present disclosure, viewed from the outside in the radial direction.

[0012] 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.

[0013] (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.

[0014] The rotating member 11 is configured to rotate about a rotation axis RA (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 RA and is configured to rotate about the rotation axis RA (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 RA (radial center) in conjunction with the rotation of the rotating shaft 11A.

[0015] Hereinafter, the direction in which the rotation axis RA 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 RA is defined as the radial direction of the rotating member 11 (rotating machine 10), and the circumferential direction around the rotation axis RA 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.

[0016] 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.

[0017] 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.

[0018] (Groove) FIG. 2 is a schematic cross-sectional view along the axial direction of the seal device 1 according to an embodiment of the present disclosure. An arc-shaped or annular groove 13 extending along the circumferential direction is formed in the stationary-side inner circumferential surface 121 of the stationary member 12. The groove 13 is recessed radially outward from the stationary-side inner circumferential surface 121. In the illustrated embodiment, as shown in FIG. 2 , the groove 13 includes a first groove portion 14 and a second groove portion 15 provided radially outward from the first groove portion 14. The second groove portion 15 communicates with the first gap G1 via the first groove portion 14. The second groove portion 15 is expanded in diameter toward one axial side (lower side in FIG. 2 ) more than the first groove portion 14 to form a one-side expanded diameter space ES1, and is expanded in diameter toward the other axial side (upper side in FIG. 2 ) more than the first groove portion 14 to form a other-side expanded diameter space ES2.

[0019] 2 , the stationary member 12 has a one-side protrusion 16 that protrudes toward the other axial side beyond a wall surface 151 on the one axial side of the second groove portion 15, and a other-side protrusion 17 that protrudes toward the one axial side beyond a wall surface 152 on the other axial side of the second groove portion 15. The first groove portion 14 is provided between the one-side protrusion 16 and the other-side protrusion 17.

[0020] (Sealing Device) The sealing device 1 according to some embodiments is a sealing structure that is provided in the rotary machine 10 and seals the first gap G1 to suppress fluid leakage through the first gap G1. Note that the rotary machine 10 may include a plurality of sealing devices 1 arranged along the circumferential direction.

[0021] Fig. 3 is a schematic cross-sectional view of a seal device 1 according to an embodiment of the present disclosure, as viewed from one side in the axial direction. Fig. 2 shows a cross-section taken along the line A-B in Fig. 1, specifically a cross-section at a circumferential position including the housing member 4 and the biasing device 5. As shown in Figs. 2 and 3, the seal device 1 according to some embodiments includes a movable seal member 2, a holding member 3, at least one housing member 4, and at least one biasing device 5. In the embodiment shown in Fig. 3, the seal device 1 includes a plurality of housing members 4 (six in the illustrated example) and a plurality of biasing devices 5 equal in number to the number of housing members 4 (six in the illustrated example).

[0022] (Movable seal member) As shown in Fig. 2 , the movable seal member 2 includes at least a main body portion 21 provided in the first gap G1. In the illustrated embodiment, the movable seal member 2 further includes a plurality of thin-plate-shaped seal fins 22 that protrude toward the rotation-side outer peripheral surface 111 and are provided on an inner peripheral surface of the main body portion 21 that faces the rotation-side outer peripheral surface 111. As shown in Fig. 3 , the main body portion 21 and the plurality of seal fins 22 have an arc shape that extends circumferentially. The movable seal member 2 exhibits a labyrinth effect between the plurality of seal fins 22 and the rotation-side outer peripheral surface 111 of the rotating member 11, suppressing leakage of fluid (steam, if the rotary machine 10 is a steam turbine) between the movable seal member 2 and the rotating member 11.

[0023] The first gap G1 has a higher pressure on one axial side (lower side in the figure) than on the other axial side (upper side in the figure) of the movable seal member 2. In other words, the first gap G1 includes a low-pressure section PS2, which is provided on the other axial side of the movable seal member 2 and through which a low-pressure fluid flows, and a high-pressure section PS1, which is provided on the one axial side of the movable seal member 2 and through which a high-pressure fluid having a higher pressure than the low-pressure fluid flows.

[0024] (Holding Member) As shown in Fig. 2, 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 at least a base portion 31 housed in the groove 13 described above. As shown in Fig. 3, the base portion 31 has 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.

[0025] The base 31 is formed with the same number of through holes 32 that penetrate along the radial direction as the number of the housing members 4. Each of the plurality of through holes 32 is formed at a position spaced apart from each other in the circumferential direction of the base 31, and a part of the corresponding housing member 4 is inserted into each of the through holes 32.

[0026] (Accommodating Member) As shown in FIG. 2 , the accommodating member 4 is separate from the holding member 3 and includes at least a cylindrical main body portion 41 extending along the radial direction and an inner flange portion 42 protruding inward from the inner circumferential surface of the radially inner end portion of the main body portion 41. In the illustrated embodiment, the accommodating member 4 further includes an outer flange portion 43 protruding outward from the outer circumferential surface of the radially outer end portion of the main body portion 41. The inner flange portion 42 and the outer flange portion 43 extend along a direction intersecting the radial direction and are annular when viewed from one side in the radial direction. In the illustrated embodiment, the main body portion 41 is formed in a cylindrical shape, and the inner flange portion 42 and the outer flange portion 43 extend along a direction intersecting the radial direction and are annular when viewed from one side in the radial direction.

[0027] The main body 41 is configured to be insertable into the through-hole 32 from the outside in the radial direction, and the radially inner portion including the inner flange 42 protrudes radially inward beyond the base 31. The accommodating member 4 has an abutment surface 421, radially inward beyond the base 31, against which the biasing member 51, arranged radially outward, abuts. In the illustrated embodiment, the radially outer surface of the inner flange 42 serves as the abutment surface 421.

[0028] The main body 41 is configured so that the biasing device 5 can be inserted from the outside in the radial direction into an internal space 44 formed by the inner circumferential surface thereof, and the biasing device 5 is accommodated in the internal space 44 .

[0029] (Using Device) As shown in Fig. 2, the urging device 5 includes at least a urging member 51 for urging the movable seal member 2 radially outward relative to the holding member 3. In the illustrated embodiment, as shown in Fig. 2, the urging device 5 further includes a head portion 52 housed in the internal space 44 of the housing member 4, and a shaft portion 53 connecting the head portion 52 and the main body portion 21 of the movable seal member 2. In this case, the urging device 5 can cause the urging member 51 to exert a urging force with a simple structure.

[0030] 2, the head 52 has a larger diameter than the shaft 53. The head 52 has an abutment surface 521 against which the radially outer surface of the biasing member 51 abuts. The shaft 53 extends radially, with one end connected to the head 52 and the other end connected to the main body 21 of the movable seal member 2 radially inward of the inner flange 42. The inner circumferential surface of the inner flange 42 forms an insertion hole for inserting the shaft 53 therethrough.

[0031] The biasing member 51 is disposed between the contact surface 521 of the head 52 and the above-described contact surface 421, which faces the contact surface 521 via a radial gap, with one end abutting against the contact surface 521 and the other end abutting against the contact surface 421. In the embodiment shown in FIG. 2 , the biasing member 51 is disposed to cover the outer periphery of the shaft portion 53 and includes a plurality of disc springs 51A stacked radially. Note that the biasing member 51 is not limited to a plurality of disc springs 51A, and may be a single disc spring 51A or a biasing member capable of exerting a biasing force other than that of the disc spring 51A, such as a compression coil spring.

[0032] In the embodiment shown in FIG. 2 , the movable seal member 2 has a threaded hole 23 provided on the outer peripheral surface of the main body 21. The shaft 53 has a threaded portion 54 formed on the outer peripheral surface of the radially inner end portion thereof that threads into the threaded hole 23. In this case, it is easy to adjust the radial gap formed between the abutment surface 521 of the head 52 and the abutment surface 421 of the inner flange 42, thereby facilitating adjustment of the initial strain of the biasing member 51. Note that each of the multiple biasing devices 5 is not limited to the embodiment shown in the figure. For example, the shaft 53 may be connected to the main body 21 of the movable seal member 2 by shrink fitting, welding, or the like.

[0033] 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 5, 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 section PS1 side acts on the outer peripheral surface of the main body 21, applying a radially inward force (i.e., a force that resists the urging force of the urging devices 5) 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.

[0034] According to the above-described sealing device 1, after the movable seal member 2 is moved along the axial direction and attached to the holding member 3, the accommodating member 4 can be attached to the holding member 3 from the outside in the radial direction, and then the biasing device 5 can be attached to the accommodating member 4 from the outside in the radial direction. Therefore, even if the accommodating member 4 has a portion that protrudes radially inward beyond the base 31, the assembly of the sealing device 1 is not impaired.

[0035] By providing the abutment surface 421 with which the biasing member 51 abuts on the accommodating member 4, which is separate from the holding member 3, the abutment surface 421 can be positioned radially inward of the base 31 without impairing the ease of assembly of the seal device 1. By positioning the abutment surface 421 radially inward of the base 31, even if the groove 13 provided in the stationary member 12 is shallow and the radial dimension of the base 31 accommodated in the groove 13 is small, it is possible to ensure a space (internal space 44) with a predetermined radial dimension inside the accommodating member 4 in which the biasing member 51 can exert a biasing force. According to this seal device 1, even if the groove 13 provided in the stationary member 12 is shallow, the seal device 1 can be installed without impairing the ease of assembly of the seal device 1.

[0036] 2 , the holding member 3 includes a radial protruding portion 33 that protrudes radially inward from the base portion 31. The radial protruding portion 33 is provided on the other axial side, i.e., on the low-pressure section PS2 side, of the through hole 32 in which the housing member 4 is housed. The movable seal member 2 has a other-side sliding surface (sliding surface) 241 that is adjacent to the radial protruding portion 33 in the axial direction and is slidable against the radial protruding portion 33.

[0037] In the illustrated embodiment, the movable seal member 2 includes an engagement portion 24 that is accommodated in and engages with the groove 13. The engagement portion 24 has a lower end connected to the main body portion 21. The other-side sliding surface 241 is a part of the end surface on the other axial side of the engagement portion 24. During load operation of the rotary machine 10, the pressure of the fluid on the high-pressure section PS1 side acts on the end surface on the one axial side of the main body portion 21, thereby applying a force in the other axial direction to the movable seal member 2. As a result, the other-side sliding surface 241 abuts against the surface on the one axial side of the radial protruding portion 33. Furthermore, the other axial side surface of the radial protruding portion 33 abuts against the end surface that defines the first groove portion 14 of the other-side protruding portion 17.

[0038] By sliding the radial protrusion 33 against the other-side sliding surface 241, the movable seal member 2 can operate without contacting the other-side protrusion 17, thereby stabilizing the operation of the movable seal member 2 when moving radially. Furthermore, if the accommodating member 4 and the holding member 3 were integral, there is a risk that the holding member 3 would interfere with arranging the radial protrusion 33 adjacent to the other-side sliding surface 241. By making the accommodating member 4 separate from the holding member 3, the accommodating member 4 can be attached to the holding member 3 after arranging the radial protrusion 33 adjacent to the other-side sliding surface 241, thereby preventing the holding member 3 from interfering with the assembly of the seal device 1.

[0039] 2 , the movable seal member 2 has a one-side sliding surface 242 that is adjacent to the end surface that defines the first groove portion 14 of the one-side protrusion 16 and is capable of sliding against the end surface of the one-side protrusion 16. The one-side sliding surface 242 is a part of the end surface on one side in the axial direction of the engagement portion 24. Note that when the seal device 1 is in operation, the movable seal member 2 moves toward the low-pressure portion PS2, and therefore the one-side sliding surface 242 does not come into contact with the end surface of the one-side protrusion 16.

[0040] In some embodiments, the above-described sealing device 1 may further include a biasing member 18 disposed between the bottom surface of the groove 13 and the outer surface of the base 31, which faces the bottom surface across a radial gap, and configured to bias the retaining member 3 radially inward. An example of the biasing member 18 is a leaf spring. One end of the biasing member 18 abuts against the bottom surface of the groove 13, and the other end of the biasing member 18 abuts against the outer surface of the base 31. In this case, the retaining member 3 is biased by the biasing member 18, and the base 31 abuts against the one-side protrusion 16 and the other-side protrusion 17, thereby restricting radial movement of the retaining member 3 and positioning the retaining member 3 in the radial direction.

[0041] In some embodiments, as shown in Fig. 2, the base 31 of the holding member 3 has a recess 34 at its radially outer end for inserting the outer flange 43. The recess 34 is formed around the through hole 32, including the radially outer edge of the through hole 32. The depth of the recess 34 is preferably the same as or greater than the thickness (radial length) of the outer flange 43. By inserting the outer flange 43 of the accommodating member 4 into the recess 34 of the holding member 3, the accommodating member 4 can be locked to the holding member 3 and an increase in the radial dimension of the sealing device 1 can be suppressed.

[0042] FIG. 4 is a schematic cross-sectional view of the sealing device 1 according to an embodiment of the present disclosure along the axial direction. FIG. 4 illustrates a cross-section taken along the arrows C-D in FIG. 1 , specifically, a cross-section taken at a circumferential position that does not include the housing member 4 and the biasing device 5. In some embodiments, as illustrated in FIGS. 2 and 4 , the base 31 has a first shoulder 35, which is an end portion on one side in the axial direction, provided in the one-side expanding space ES1, and a second shoulder 36, which is an end portion on the other side in the axial direction, provided in the other-side expanding space ES2. The first shoulder 35 is a protruding portion that protrudes radially outward from the one-side sliding surface 242 toward the one side in the axial direction relative to the one-side sliding surface 242. The second shoulder 36 is a protruding portion that protrudes radially outward from the other-side sliding surface 241 toward the other side in the axial direction relative to the other-side sliding surface 241.

[0043] 2, when the sealing device 1 is activated, the ends (first shoulder 35, second shoulder 36) of the base 31 provided in the one-side expanding space ES1 and the other-side expanding space ES2 can be engaged with the portions (one-side protrusion 16, other-side protrusion 17) that form the first groove 14 of the stationary member 12. In addition, the base 31 is formed with a through hole 32 for accommodating the accommodating member 4, and by increasing the axial length of the base 31, the strength of the base 31 can be improved.

[0044] 4 , the engaging portion 24 has a third shoulder 25, which is an end portion on one axial side, provided in the one-side expanded diameter space ES1, and a fourth shoulder 26, which is an end portion on the other axial side, provided in the other-side expanded diameter space ES2, in a circumferential range different from the circumferential range in which the accommodating member 4 is provided. The third shoulder 25 is a protruding portion that protrudes radially outward from the one-side sliding surface 242 toward the one axial side beyond the one-side sliding surface 242. The fourth shoulder 26 is a protruding portion that protrudes radially outward from the other-side sliding surface 241 toward the other axial side beyond the other-side sliding surface 241.

[0045] As shown in Figure 4, when the sealing device 1 is operated, the end portions (third shoulder portion 25, fourth shoulder portion 26) provided in the one-side expansion space ES1 and the other-side expansion space ES2 of the engagement portion 24 can be engaged with the portions (one-side protrusion portion 16, other-side protrusion portion 17) forming the first groove portion 14 of the stationary member 12.

[0046] 5 is an explanatory diagram illustrating stress acting on the engagement portion 24 of the movable seal member 2 in the seal device 1 according to an embodiment of the present disclosure. Because the third shoulder 25 of the engagement portion 24 engages with the one-side protrusion 16, stress acting on the base of the third shoulder 25 is higher than that acting on other portions. Similarly, because the fourth shoulder 26 of the engagement portion 24 engages with the other-side protrusion 17, stress acting on the base of the fourth shoulder 26 is higher than that acting on other portions. Because the third shoulder 25 is on the high-pressure section PS1 side, stress acting on the third shoulder 25 is higher than that acting on the fourth shoulder 26 on the low-pressure section PS2 side.

[0047] In some embodiments, the third shoulder 25 of the engaging portion 24 is thicker than the fourth shoulder 26. In the embodiment shown in FIG. 4 , the thickness (radial dimension) of the portion of the third shoulder 25 that engages with the one-side protrusion 16 is defined as T1, and the thickness (radial dimension) of the portion of the fourth shoulder 26 that engages with the other-side protrusion 17 is defined as T2. The thickness T1 satisfies the condition T1 > T2. If the thicknesses of the third shoulder 25 and the fourth shoulder 26 are not uniform, it is preferable to compare the minimum thicknesses T1 and T2. By making the third shoulder 25 of the engaging portion 24 thicker than the fourth shoulder 26, the stress load on the third shoulder 25 can be reduced.

[0048] Fig. 6 is a schematic perspective view of a seal device 1 according to an embodiment of the present disclosure. Fig. 7 is a schematic view of the housing member 4 and the engagement portion 24 of the movable seal member 2 of the seal device 1 shown in Fig. 6, viewed from the outside in the radial direction. As shown in Fig. 6, the base 31 of the holding member 3 is formed with a rectangular insertion hole 311 for inserting the fourth shoulder 26 radially inward of the second shoulder 36.

[0049] In some embodiments, the above-described housing member 4 has a non-circular outer contour 45 having a major axis LA extending along the axial direction and a minor axis SA extending along the circumferential direction when viewed from one radial side, as shown in FIG. 7 . In the illustrated embodiment, the outer contour 45 has both axial ends formed in an arc shape and both circumferential ends having sides extending along the axial direction as if cut out. In the illustrated embodiment, the outer contour 45 is formed on the outer flange 43, but the outer contour 45 may be formed on both the main body 41 and the outer flange 43, or on the main body 41.

[0050] By configuring the outer contour shape 45 of the accommodating member 4 to have a minor axis SA extending along the circumferential direction, the engaging portion 24 of the movable seal member 2 can be extended to a position adjacent to the accommodating member 4 in the circumferential direction. This allows the circumferential lengths of the ends (third shoulder 25, fourth shoulder 26) provided in the one-side expanded diameter space ES1 and the other-side expanded diameter space ES2 of the engaging portion 24 to be increased, thereby reducing the stress burden on the ends (third shoulder 25, fourth shoulder 26).

[0051] In some embodiments, as shown in FIG. 7, when viewed from one radial side, the engaging portion 24 is partially located inside an imaginary circle VC connecting the tips P1 and P2 of the long axis LA of the outer flange portion 43 (housing member 4).

[0052] By extending the engaging portion 24 of the movable sealing member 2 to the inside of the virtual circle VC in the circumferential direction, the circumferential length of the end portions (third shoulder portion 25, fourth shoulder portion 26) provided in the one side expansion space ES1 and the other side expansion space ES2 of the engaging portion 24 can be increased, and the stress burden on the above end portions (third shoulder portion 25, fourth shoulder portion 26) can be reduced.

[0053] 8 is a schematic perspective view of a seal device 1 according to an embodiment of the present disclosure. In some embodiments, as shown in FIG. 8 , the first shoulder 35 has a notch 37 cut out toward the other axial side in a circumferential range different from the circumferential range in which the housing member 4 is provided. In the illustrated embodiment, the notch 37 includes a base extending along the circumferential direction and two side edges extending along the axial direction from both ends of the base. The notch 37 is formed on either one or the other circumferential side, or on both the one and the other circumferential sides, relative to the housing member 4. The third shoulder 25 has an insertion portion 27 that protrudes radially outward and inserts into the notch 37.

[0054] The end (third shoulder 25) of the engaging portion 24 located in the expanded diameter space ES1 is located on the high-pressure section PS1 side, and therefore experiences higher stress than the end (fourth shoulder 26) located in the expanded diameter space ES2 located on the low-pressure section PS2 side. By providing the fitting portion 27 on the third shoulder 25, the thickness of the portion having the fitting portion 27, i.e., the radial dimension, can be increased. This reduces the stress load on the third shoulder 25.

[0055] 9 is a schematic diagram of the accommodating member 4 and the engaging portion 24 of the movable seal member 2 of the seal device 1 according to one embodiment of the present disclosure, viewed from the outside in the radial direction. In some embodiments, the accommodating member 4 described above has a convexly curved outer contour shape 46 that protrudes toward one circumferential side when viewed from one radial side, as shown in FIG. In the illustrated embodiment, the accommodating member 4 has a convexly curved outer contour shape 47 that protrudes toward the other circumferential side when viewed from one radial side. The outer contour shape 46 and the outer contour shape 47 are part of a circular outer contour. In the illustrated embodiment, the outer contour shape 46 and the outer contour shape 47 are formed on both the main body portion 41 and the outer flange portion 43.

[0056] The above-described engaging portion 24 has concave curved portions 28, 29 on the circumferential side where the accommodating member 4 is located that are recessed to follow the outer contour shapes 46, 47 of the accommodating member 4. The engaging portion 24 on the other circumferential side where the accommodating member 4 is adjacent has a concave curved portion 28 on the other circumferential side that is recessed to follow the outer contour shape 46. The concave curved portion 28 is provided at a position adjacent to the outer contour shape 46 in the circumferential direction. In the illustrated embodiment, the concave curved portion 28 has portions that extend to the other circumferential side beyond the circumferential end 461 of the outer contour shape 46 on the one axial side and the other axial side.

[0057] The engaging portion 24, with the accommodation member 4 adjacent on one side in the circumferential direction, has a concave curved portion 29 on one side in the circumferential direction that is recessed to follow the outer contour shape 47. The concave curved portion 29 is provided at a position adjacent to the outer contour shape 47 in the circumferential direction. In the illustrated embodiment, the concave curved portion 29 has portions that extend to the other circumferential side beyond a circumferential end 471 of the outer contour shape 47 on the one side and the other side in the axial direction.

[0058] By providing the concave curved portions 28, 29 on the side of the engaging portion 24 facing the accommodating member 4, the engaging portion 24 of the movable seal member 2 can be extended in the circumferential direction to a position adjacent to the accommodating member 4. This allows the circumferential lengths of the ends (third shoulder 25, fourth shoulder 26) provided in the one-side expanded diameter space ES1 and the other-side expanded diameter space ES2 of the engaging portion 24 to be increased, thereby reducing the stress burden on the ends (third shoulder 25, fourth shoulder 26).

[0059] 3, the at least one biasing device 5 includes a plurality of biasing devices 5 spaced apart in the circumferential direction, and the at least one housing member 4 includes a plurality of housing members 4 that respectively house the biasing devices 5. The plurality of biasing devices 5 are preferably evenly spaced in the circumferential direction. In one embodiment, each of the plurality of biasing devices 5 is at a circumferential angle of ±5° relative to a circumferentially adjacent biasing device 5.

[0060] By applying a biasing force to the movable seal member 2 from a plurality of locations in the circumferential direction using a plurality of biasing devices 5, the moment acting on the movable seal member 2 can be well balanced.

[0061] 1 , a rotary machine 10 according to some embodiments includes the above-described rotary member 11, the above-described stationary member 12, and at least one of the above-described seal devices 1. Even if the groove 13 provided in the stationary member 12 has a shallow depth, the rotary machine 10 can mount the seal device 1 without impairing the assembly ability of the seal device 1.

[0062] 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.

[0063] 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.

[0064] The contents of the above-described embodiments can be understood, for example, as follows.

[0065] 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) provided in the first gap (G1); a holding member (3) for supporting the movable sealing member (2) arranged radially inward so as to be movable along the radial direction, the holding member (3) including at least a base (31) accommodated in a groove (13) provided in the circumferential direction of the stationary member (12); and at least one biasing device (5) including a biasing member (51) for biasing the movable sealing member (2) radially outward relative to the holding member (3) along the radial direction. and at least one housing member (4) that houses the biasing device (5) and is partially housed in the holding member (3), the housing member (4) having an abutment surface (421) that is radially inward of the base (31) and against which the biasing member (51) arranged radially outward abuts.

[0066] According to the configuration of 1) above, by providing an abutment surface (421) with which the biasing member (51) abuts on the housing member (4), which is separate from the holding member (3), the abutment surface (421) can be positioned radially inward from the base (31) without impairing the assembly of the sealing device (1). By positioning the abutment surface (421) radially inward from the base (31), even if the groove (13) provided in the stationary member (12) is shallow and the radial dimension of the base (31) accommodated in the groove (13) is small, a space having a predetermined radial dimension within the housing member (4) in which the biasing member (51) can exert a biasing force can be secured. Therefore, according to the configuration of 1) above, even if the groove (13) provided in the stationary member (12) is shallow, the sealing device (1) can be installed without impairing the assembly of the sealing device (1).

[0067] 2) In some embodiments, in the sealing device (1) described in 1) above, the accommodating member (4) has a flange portion (outer flange portion 43) that protrudes from the outer end portion in the radial direction along a direction intersecting the radial direction, and the retaining member (3) has a recess (34) at the outer end portion in the radial direction for inserting the flange portion (outer flange portion 43) of the accommodating member (4).

[0068] According to the configuration of 2) above, by inserting the flange portion (outer flange portion 43) of the accommodating member (4) into the recess (34) of the holding member (3), the accommodating member (4) can be engaged with the holding member (3) and an increase in the radial dimension of the sealing device (1) can be suppressed.

[0069] 3) In some embodiments, in the sealing device (1) described in 1) or 2) above, the groove (13) provided in the stationary member (12) includes: a first groove portion (14); and a second groove portion (15) provided radially outward of the first groove portion (14), the second groove portion (15) expanding in diameter toward one side in the axial direction more than the first groove portion (14) to form a one-side expanded diameter space (ES1), and expanding in diameter toward the other side in the axial direction more than the first groove portion (14) to form an other-side expanded diameter space (ES2), and the base (31) has an end portion (first shoulder portion 35) on the one side in the axial direction provided in the one-side expanded diameter space (ES1) and an end portion (second shoulder portion 36) on the other side in the axial direction provided in the other-side expanded diameter space (ES2).

[0070] According to the configuration of 3) above, when the sealing device 1 is activated, the end portions (first shoulder 35, second shoulder 36) provided in the one-side expanding space ES1 and the other-side expanding space ES2 of the base 31 can be engaged with the portion forming the first groove 14 of the stationary member 12. Furthermore, according to the configuration of 3) above, the base 31 has a hole (through hole 32) for accommodating the accommodating member 4, and by increasing the axial length of the base 31, the strength of the base 31 can be improved.

[0071] 4) In some embodiments, in the seal device (1) described in 3) above, the movable seal member (2) includes an engagement portion (24) that is accommodated in the groove (13) and engages with the groove (13), and the engagement portion (24) is arranged such that, in a circumferential range different from the circumferential range in which the accommodation member (4) is provided, the end portion (third shoulder portion 25) on one side in the axial direction is provided in the one-side expansion space (ES1) and the end portion (fourth shoulder portion 26) on the other side in the axial direction is provided in the other-side expansion space (ES2).

[0072] According to the configuration of 4) above, when the sealing device (1) is operated, the end portions (third shoulder portion 25, fourth shoulder portion 26) provided in the one-side expansion space (ES1) and the other-side expansion space (ES2) of the engagement portion (24) can be engaged with the portion forming the first groove portion (14) of the stationary member (12).

[0073] 5) In some embodiments, the seal device (1) is as described in 4) above, wherein the movable seal member (2) is provided in the axial direction between a high-pressure section (PS1) through which a high-pressure fluid flows and a low-pressure section (PS2) which is located on the other side of the axial direction from the high-pressure section (PS1) and through which a lower-pressure fluid flows than the high-pressure fluid, and the engaging portion (24) has a thickness at the end on one side (third shoulder portion 25) that is greater than the thickness at the end on the other side (fourth shoulder portion 26).

[0074] According to the configuration of 5) above, the one end (third shoulder 25) of the engaging portion 24 is on the high-pressure portion (PS1) side, and therefore is subjected to a higher stress than the other end (fourth shoulder 26) which is on the low-pressure portion (PS2) side. By making the one end (third shoulder 25) of the engaging portion 24 thicker than the other end (fourth shoulder 26), the stress burden on the one end (third shoulder 25) of the engaging portion 24 can be reduced.

[0075] 6) In some embodiments, the sealing device (1) is as described in 4) or 5) above, wherein the accommodating member (4) has a non-circular outer contour shape (45) having a major axis (LA) extending along the axial direction and a minor axis (SA) extending along the circumferential direction when viewed from one side in the radial direction.

[0076] According to the configuration of 6) above, by forming the outer contour shape (45) of the housing member (4) to have a minor axis extending along the circumferential direction, the engaging portion (24) of the movable seal member (2) can be extended to a position adjacent to the housing member (4) in the circumferential direction. This allows the circumferential lengths of the ends (third shoulder 25, fourth shoulder 26) provided in the one-side expanding diameter space (ES1) and the other-side expanding diameter space (ES2) of the engaging portion (24) to be increased, thereby reducing the stress burden on the ends (third shoulder 25, fourth shoulder 26).

[0077] 7) In some embodiments, in the sealing device (1) described in 6) above, a portion of the engaging portion (24) is provided inside an imaginary circle (VC) connecting the tips (P1, P2) of the long axis (LA) of the accommodating member (4) when viewed from one side in the radial direction.

[0078] According to the configuration of 7) above, by extending the engaging portion (24) of the movable sealing member (2) to the inside of the virtual circle (VC) in the circumferential direction, the circumferential lengths of the end portions (third shoulder portion 25, fourth shoulder portion 26) provided in the one-side expanding space (ES1) and the other-side expanding space (ES2) of the engaging portion (24) can be increased, and the stress burden on the above-mentioned end portions (third shoulder portion 25, fourth shoulder portion 26) can be reduced.

[0079] 8) In some embodiments, the sealing device (1) is as described in 4) or 5) above, wherein the accommodating member (4) has a convexly curved outer contour shape (46) that protrudes toward one side in the circumferential direction when viewed from one side in the radial direction, and the engaging portion (24) has a concavely curved portion (28) that is recessed to follow the outer contour shape (46) of the accommodating member (4) on the side where the accommodating member (4) is located in the circumferential direction.

[0080] According to the configuration of 8) above, by providing the concave curved portion 28 on the side of the engaging portion 24 facing the housing member 4, the engaging portion 24 of the movable seal member 2 can be extended to a position adjacent to the housing member 4 in the circumferential direction. This allows the circumferential lengths of the ends (third shoulder 25, fourth shoulder 26) provided in the one-side expanding diameter space ES1 and the other-side expanding diameter space ES2 of the engaging portion 24 to be increased, thereby reducing the stress burden on the ends (third shoulder 25, fourth shoulder 26).

[0081] 9) In some embodiments, the seal device (1) is described in any one of 4) to 8) above, wherein the movable seal member (2) is provided in the axial direction between a high-pressure section (PS1) through which a high-pressure fluid flows and a low-pressure section (PS2) located on the other side of the axial direction from the high-pressure section (PS1) and through which a lower-pressure fluid flows than the high-pressure fluid, the end (first shoulder portion 35) provided in the one-side expanded diameter space (ES1) of the base (31) has a notch portion (37) cut out toward the other side in the axial direction in a circumferential range different from the circumferential range in which the accommodating member (4) is provided, and the end (third shoulder portion 25) provided in the one-side expanded diameter space (ES1) of the engaging portion (24) has an insertion portion (27) that protrudes radially outward and inserts into the notch portion (37).

[0082] According to the configuration of 9) above, the end (third shoulder 25) of the engaging portion 24 provided in the one-side expanding diameter space ES1 is located on the high-pressure section PS1 side, and therefore is subjected to higher stress than the end (fourth shoulder 26) provided in the other-side expanding diameter space ES2, which is located on the low-pressure section PS2 side. By providing the fitting portion 27 at the end (third shoulder 25) provided in the one-side expanding diameter space ES1 of the engaging portion 24, the wall thickness, i.e., the radial dimension, of the portion having the fitting portion 27 can be increased. This reduces the stress burden on the end (third shoulder 25) provided in the one-side expanding diameter space ES1.

[0083] 10) In some embodiments, in the seal device (1) described in any of 1) to 9) above, the retaining member (3) further includes a radial protrusion (33) protruding radially inward from the base (31), and the movable seal member (2) has a sliding surface (other-side sliding surface 241) adjacent to the radial protrusion (33) in the axial direction and slidable against the radial protrusion (33).

[0084] According to the configuration of 10) above, by sliding the radial protrusions (33) against the sliding surface (241), the operation of the movable seal member (2) when moving radially can be stabilized. Furthermore, if the accommodating member (4) and the holding member (3) were integral, there was a risk that the holding member (3) would interfere with arranging the radial protrusions (33) adjacent to the sliding surface (241). By making the accommodating member (4) separate from the holding member (3), the accommodating member (4) can be attached to the holding member (3) after arranging the radial protrusions (33) adjacent to the sliding surface (241), thereby preventing the holding member (3) from interfering with the assembly of the seal device (1).

[0085] 11) In some embodiments, in the seal device (1) described in any one of 1) to 10) above, the biasing device (5) includes: a head (52) accommodated in the accommodation member (4), the head (52) having an abutment surface against which the biasing member (51) abuts; and a shaft portion (53) connecting the head (52) and the movable seal member (2).

[0086] According to the configuration of 11) above, the biasing device (5) can make the biasing member (51) exert a biasing force with a simple structure.

[0087] 12) In some embodiments, the sealing device (1) is described in any one of 1) to 11) above, wherein the at least one biasing device (5) includes a plurality of biasing devices (5) spaced apart in the circumferential direction, and the at least one accommodating member (4) includes a plurality of accommodating members (4) that respectively accommodate the biasing devices (5).

[0088] According to the configuration of 12) above, by applying a biasing force to the movable seal member (2) from multiple locations in the circumferential direction using multiple biasing devices (5), it is possible to achieve a good balance of the moment acting on the movable seal member (2).

[0089] 13) A rotary machine (10) according to at least one embodiment of the present disclosure comprises: a sealing device (1) according to any one of 1) to 12) above; the rotating member (11); and the stationary member (12).

[0090] According to the above configuration 13), the rotary machine (10) can be equipped with the seal device (1) without impairing the assembly of the seal device (1), even if the groove (13) provided in the stationary member (12) is shallow.

[0091] DESCRIPTION OF SYMBOLS 1 Sealing device 2 Movable sealing member 3 Holding member 4 Storage member 5 Biasing device 10 Rotating machine 11 Rotating member 12 Stationary member 13 Groove 14 First groove portion 15 Second groove portion 16 One-side protrusion portion 17 Other-side protrusion portion 21, 41 Main body portion 22 Seal fin 23 Screw hole 31 Base portion 32 Through hole 42 Inner flange portion 43 Outer flange portion 44 Internal space 51 Biasing member 51A Disc spring 52 Head portion 53 Shaft portion 54 Threaded portion 421, 521 Abutment surface ES1 One-side expanded diameter space ES2 Other-side expanded diameter space G1 First gap RA Rotation axis PS1 High-pressure portion PS2 Low-pressure portion

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 sealing member arranged in the first gap; a holding member for supporting the movable sealing member arranged radially inward so that it can move along the radial direction, the holding member including at least a base that is housed in a groove arranged circumferentially in the stationary member; at least one biasing device including a biasing member for biasing the movable sealing member radially outward relative to the holding member; and at least one housing member that houses the biasing device and is partially housed in the holding member, the at least one housing member having an abutment surface that is radially inward of the base and against which the biasing member arranged radially outward abuts.

2. A sealing device as set forth in claim 1, wherein the accommodating member has a flange that protrudes from its outer end in the radial direction in a direction intersecting the radial direction, and the holding member has a recess in its outer end in the radial direction for inserting the flange of the accommodating member.

3. A sealing device as claimed in claim 1 or 2, wherein the groove provided in the stationary member includes a first groove portion and a second groove portion provided radially outward of the first groove portion, the second groove portion expanding in diameter to one side in the axial direction more than the first groove portion to form a one-side expanded diameter space, and expanding in diameter to the other side in the axial direction more than the first groove portion to form an other-side expanded diameter space, and wherein the end of the base portion on one side in the axial direction is provided in the one-side expanded diameter space, and the end of the base portion on the other side in the axial direction is provided in the other-side expanded diameter space.

4. A sealing device as described in claim 3, wherein the movable seal member includes an engaging portion that is accommodated in the groove and engages with the groove, and the engaging portion has an end on one side in the axial direction that is provided in the one-side expanded diameter space and an end on the other side in the axial direction that is provided in the other-side expanded diameter space, in a circumferential range different from the circumferential range in which the accommodation member is provided.

5. A sealing device as described in claim 4, wherein the movable seal member is provided in the axial direction between a high-pressure section through which a high-pressure fluid flows and a low-pressure section located on the other side of the high-pressure section in the axial direction and through which a lower-pressure fluid flows than the high-pressure fluid, and the engaging section has a thickness at the end on one side that is thicker than the end on the other side.

6. A sealing device as set forth in claim 4, wherein the housing member has a non-circular outer contour shape having a major axis extending along the axial direction and a minor axis extending along the circumferential direction when viewed from one side in the radial direction.

7. The sealing device according to claim 6, wherein a portion of the engaging portion is provided inside an imaginary circle connecting the tips of the long axes of the accommodating member when viewed from one side in the radial direction.

8. A sealing device as described in claim 4, wherein the accommodating member has a convexly curved outer contour shape that protrudes toward one side in the circumferential direction when viewed from one side in the radial direction, and the engaging portion has a concavely curved portion that is recessed to follow the outer contour shape of the accommodating member on the side where the accommodating member is located in the circumferential direction.

9. The sealing device according to claim 4, wherein the movable sealing member is provided in the axial direction between a high-pressure section through which a high-pressure fluid flows and a low-pressure section located on the other side of the high-pressure section in the axial direction and through which a fluid with a lower pressure than the high-pressure fluid flows, and the end provided in the one-side expanded diameter space of the base has a notch portion cut out toward the other side in the axial direction in a circumferential range different from the circumferential range in which the accommodating member is provided, and the end provided in the one-side expanded diameter space of the engaging portion has an insertion portion that protrudes radially outward and inserts into the notch portion.

10. A seal device as described in claim 1 or 2, wherein the retaining member further includes a radial protrusion that protrudes radially inward from the base, and the movable seal member has a sliding surface that is adjacent to the radial protrusion in the axial direction and is capable of sliding against the radial protrusion.

11. A sealing device as claimed in claim 1 or 2, wherein the biasing device includes a head portion housed in the housing member and having a contact surface against which the biasing member contacts, and a shaft portion connecting the head portion and the movable seal member.

12. A seal device according to claim 1 or 2, wherein the at least one biasing device includes a plurality of biasing devices spaced apart in the circumferential direction, and the at least one housing member includes a plurality of housing members that house the biasing devices respectively.

13. A rotary machine comprising: the sealing device according to claim 1 or 2; the rotating member; and the stationary member.

Images