Shaft sealing device and rotating machinery

Abstract

A shaft sealing device according to at least one embodiment of the present disclosure includes: a plurality of thin plates arranged circumferentially around a rotating shaft and having a width in the axial direction of the rotating shaft; and a seal ring including a seal mounting groove for mounting the plurality of thin plates. The inner wall of the seal mounting groove on one axial side has a groove formed along the circumferential direction in a region radially inward of the rotating shaft.

Description

Technical Field

[0001] The present disclosure relates to a shaft sealing device and a rotating machine.

[0002] This application claims priority based on Japanese Patent Application No. 2021-126309 filed with the Japan Patent Office on July 30, 2021, and the contents of which are incorporated herein by reference. Background Art

[0003] Typically, in gas turbines, steam turbines, and the like, a shaft sealing device is provided around the rotating shaft to reduce the amount of gas leaking from the high-pressure side to the low-pressure side. A leaf seal (registered trademark) is known as an example of a shaft sealing device (e.g., see Patent Document 1).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2005-2995 Summary of the Invention

[0007] Problems to be solved by the invention

[0008] Compared to labyrinth seals, for example, lamella seals can reduce leakage. Furthermore, during rated operation of the rotating machinery, the lamella tips of lamellae do not come into contact with the mating component, resulting in a relatively long service life. However, lamella seals have a large number of components, which can lead to high costs.

[0009] In view of the above circumstances, an object of at least one embodiment of the present disclosure is to reduce the cost of a shaft sealing device.

[0010] Solutions to Problems

[0011] (1) A shaft sealing device according to at least one embodiment of the present disclosure includes:

[0012] a plurality of thin plates arranged in a circumferential direction of the rotating shaft and having a width in an axial direction of the rotating shaft; and

[0013] a sealing ring comprising a seal mounting groove for mounting the plurality of thin plates,

[0014] An inner wall of the seal mounting groove on one side in the axial direction has a groove formed along the circumferential direction in a region radially inside the rotary shaft.

[0015] (2) A rotary machine according to at least one embodiment of the present disclosure includes:

[0016] the rotation axis; and

[0017] The shaft sealing device according to any one of claims 1 to 8.

[0018] Effects of the Invention

[0019] According to at least one embodiment of the present disclosure, the cost of the shaft sealing device can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram showing an example of a gas turbine system including a rotary machine according to an embodiment.

[0021] Figure 2 It is a schematic cross-sectional view showing the outline of the shaft sealing device according to the present embodiment.

[0022] Figure 3 It is a schematic cross-sectional view showing an outline of a shaft sealing device according to one embodiment.

[0023] Figure 4 It is a schematic cross-sectional view schematically showing an outline of a shaft sealing device according to another embodiment.

[0024] Figure 5 is equivalent to Figure 3 A cross-sectional view taken along the VV line.

[0025] Figure 6A yes Figure 5 The cross-sectional view taken along the line VI-VI shows an example of a groove.

[0026] Figure 6B yes Figure 5 The cross-sectional view taken along the line VI-VI shows another example of the groove.

[0027] Figure 7 This is a schematic cross-sectional view schematically showing an outline of a conventional shaft sealing device including a plurality of thin sheets. DETAILED DESCRIPTION

[0028] Hereinafter, several embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, and relative arrangements of the components described in the embodiments or shown in the drawings are not intended to limit the scope of the present invention and are merely illustrative examples.

[0029] For example, expressions such as "in a certain direction", "along a certain direction", "parallel", "orthogonal", "center", "concentric" or "coaxial" that indicate relative or absolute configurations not only indicate such configurations in a strict sense, but also indicate a state of relative displacement at an angle or distance with a tolerance or a degree that can achieve the same function.

[0030] For example, expressions such as “same,” “equal,” and “homogeneous” indicating a state in which things are equal not only indicate a state of being strictly equal but also indicate a state in which there is a tolerance or a degree of difference to which the same function can be obtained.

[0031] For example, expressions indicating shapes such as a quadrilateral and a cylinder not only indicate shapes such as a quadrilateral and a cylinder in a strict geometric sense, but also indicate shapes including concave and convex portions, chamfered portions, and the like as long as the same effect can be obtained.

[0032] On the other hand, expressions such as “having,” “containing,” “equipped with,” “including,” or “having” a component are not exclusive expressions that exclude the presence of other components.

[0033] The following describes one embodiment of a shaft sealing device and a rotary machine using the same, with reference to the accompanying drawings. However, the present disclosure is not limited thereto. Furthermore, while this embodiment illustrates the rotary machine to which the present disclosure is applied, such as a turbine or compressor in a gas turbine system, the present disclosure can also be applied to rotating shafts of other rotary machines, such as steam turbines, water wheels, refrigerators, pumps, and aircraft gas turbine engines.

[0034] It should be noted that the same reference numerals are given to the common components in each embodiment to avoid duplication of description.

[0035] Figure 1 1 is a schematic diagram showing an example of a gas turbine system 1 including a rotary machine according to an embodiment. Figure 1 As shown, the gas turbine system 1 includes: a compressor (rotating machine) 2, which compresses air G1 to form compressed air G2; a combustor 3, which supplies and mixes fuel to the compressed air G2 compressed by the compressor 2 to cause combustion; a turbine (rotating machine) 4, which is supplied with the combustion gas G3 burned by the combustor 3; and a rotor 5, which has a rotating shaft 50 that connects a rotating shaft 51 arranged in the compressor 2 and a rotating shaft 52 arranged in the turbine 4.

[0036] The compressor 2 includes a housing 2K that introduces air G1 into its interior. The compressor 2 compresses the air introduced into the interior of the housing 2K to form compressed air G2. The compressor 2 includes a support 2S having a bearing that rotatably supports a rotating shaft 50.

[0037] The turbine 4 includes a casing 4K that introduces the combustion gas G3 into its interior. The turbine 4 introduces the combustion gas G3 generated by the combustor 3 into the interior of the casing 4K, causing it to expand and convert the thermal energy of the combustion gas G3 into rotational energy. The turbine 4 is provided with a support portion 4S having bearings that rotatably support the rotating shaft 50.

[0038] The rotor 5 includes rotor blades 51A provided on a rotating shaft 51 disposed in the internal space of the casing 2K, and rotor blades 52A provided on a rotating shaft 52 disposed in the internal space of the casing 4K.

[0039] The compressor 2 includes stationary blades 2A disposed in the casing 2K. A plurality of stationary blades 2A of the compressor 2 and moving blades 51A provided on the rotating shaft 51 are alternately disposed in a direction parallel to the axis AX of the rotating shaft 50 .

[0040] The turbine 4 includes stationary blades 4A disposed in a casing 4K. A plurality of stationary blades 4A of the turbine 4 and moving blades 52A provided on the rotating shaft 52 are alternately disposed in the axial direction of the rotating shaft 50 .

[0041] The gas turbine system 1 also includes a shaft seal 10, which is located on the inner periphery of the vanes 2A within the casing 2K of the compressor 2 and seals the circumference of the rotating shaft 51; and a shaft seal 10, which is located within the casing 4K of the turbine 4 and seals the circumference of the rotating shaft 52. The shaft seal 10 located in the compressor 2 prevents compressed air G2, the working fluid, from leaking from the high-pressure space to the low-pressure space. Furthermore, the shaft seal 10 of the compressor 2 is located in the support portion 2S. The shaft seal 10 located in the turbine 4 prevents combustion gas G3, the working fluid, from leaking from the high-pressure space to the low-pressure space. The shaft seal 10 of the turbine 4 is located on the inner periphery of the vanes 4A. Furthermore, the shaft seal 10 of the turbine 4 is located in the support portion 4S.

[0042] In the gas turbine system 1, combustion gas G3 introduced from the combustor 3 is supplied to the rotor blades 52A within the turbine 4. As a result, the thermal energy of the combustion gas G3 is converted into mechanical rotational energy, generating power. A portion of the power generated by the turbine 4 is transmitted to the compressor 2 via the rotating shaft 50. A portion of the power generated by the turbine 4 is utilized as power for the compressor 2.

[0043] Next, refer to Figure 2 The shaft sealing device 10 according to this embodiment will be described.

[0044] Figure 2 It is a schematic cross-sectional view showing the outline of the shaft sealing device 10 according to the present embodiment.

[0045] It should be noted that Figure 2 is equivalent to Figure 1 The cross-sectional view taken along the line II-II shows only the sealing segment 11 .

[0046] Figure 3 1 is a schematic cross-sectional view schematically showing a shaft sealing device 10 according to one embodiment, and shows a cross section including the axis AX of the rotating shaft 52 .

[0047] Figure 4 1 is a schematic cross-sectional view schematically showing a shaft sealing device 10 according to another embodiment, and shows a cross section including the axis AX of the rotating shaft 52 .

[0048] In the following description, the shaft sealing device 10 provided in the turbine 4 is described, among the shaft sealing devices 10 provided in the compressor 2 and the turbine 4. It should be noted that the structure of the shaft sealing device 10 provided in the compressor 2 is the same as that of the shaft sealing device 10 provided in the turbine 4.

[0049] like Figure 2 As shown, the shaft sealing device 10 includes a plurality of seal segments 11 arranged around the rotating shaft 52. Each seal segment 11 has an arcuate shape in a plane perpendicular to the axis AX. In this embodiment, eight seal segments 11 are arranged around the rotating shaft 50, for example. One of two circumferentially adjacent seal segments 11 is referred to as a first segment 11A, and the other as a second segment 11B.

[0050] Each seal segment 11 includes a plurality of thin sheets (plates) 20 arranged around the rotating shaft 52 , a high-pressure side plate 41 , and a seal ring 30 including a seal mounting groove 31 for mounting the plurality of thin sheets 20 .

[0051] It should be noted that, as described in detail below, Figure 4 In the shaft sealing device 10 of another embodiment shown, the seal ring 30 is divided into a low-pressure side seal ring (first member) 301 and a high-pressure side seal ring (second member) 302 .

[0052] exist Figure 3 In the shaft sealing device 10 of the illustrated embodiment, each seal segment body 11 includes a coil spring 43 and a pressing bolt 45 .

[0053] exist Figure 4 In the shaft sealing device 10 of another embodiment shown, each seal segment 11 includes a shim 47 and a fastening bolt 48. The fastening bolt 48 is a bolt for connecting and integrating the low-pressure side seal ring 301 and the high-pressure side seal ring 302.

[0054] like Figure 3and Figure 4 As shown, in this embodiment, the seal segment 11 is inserted into the recess 9a of the housing 9, corresponding to the vane 4A, with at least a portion disposed therein. The recess 9a has an opening 9k located inward in the radial direction D3. The recess 9a extends along the circumferential direction D2 of the rotating shaft 52. A portion of the sheet 20 protrudes outward from the recess 9a. It should be noted that the housing 9 is also provided on the vane 2A, the support portion 2S, and the support portion 4S.

[0055] (sheet 20)

[0056] In this embodiment, the plurality of thin sheets 20 are each a flexible, elastically deformable plate-like member in the circumferential direction D2 of the rotating shaft 52. In this embodiment, the thin sheets 20 are thin steel plates. The width direction of the thin sheets 20 is substantially aligned with the axial direction D1 of the rotating shaft 52. The normal to the surface of the thin sheets 20 is perpendicular to the axis AX of the rotating shaft 52 and extends in a direction inclined relative to the circumferential direction D2 and the radial direction D3 of the rotating shaft 52. In other words, the thickness direction of the thin sheets 20 extends in a direction perpendicular to the axis AX of the rotating shaft 52 and in a direction inclined relative to the circumferential direction D2 and the radial direction D3 of the rotating shaft 52.

[0057] More specifically, the sheet 20 is inclined so as to face the downstream side in the rotation direction of the rotating shaft 52 as it faces the inner side in the radial direction D3 .

[0058] It should be noted that in Figure 2 In FIG. 5 , the direction of the arrow indicating the circumferential direction D2 indicates the rotation direction of the rotation shaft 52 .

[0059] With such a structure, the sheet 20 has relatively high rigidity in the axial direction D1 of the rotation shaft 52 .

[0060] In this embodiment, a plurality of thin sheets 20 are arranged at intervals in the circumferential direction D2 of the rotating shaft 52. A gap S is formed between the thin sheets 20 and the thin sheets 20 adjacent to the thin sheets 20 (see Figure 2 ). A plurality of thin sheets 20 form a sheet stack 12 which is an aggregate (stack) of the plurality of thin sheets 20 .

[0061] In this embodiment, the sheet stack 12 composed of a plurality of sheets 20 seals the periphery of the rotating shaft 52, thereby dividing the space around the rotating shaft 52 into two spaces in the axial direction D1 of the rotating shaft 52. In this embodiment, the sheet stack 12 divides the space around the rotating shaft 52 into a high-pressure space (high-pressure side region) and a low-pressure space (low-pressure side region) having a relatively lower pressure than the high-pressure space.

[0062] In this embodiment, the plurality of thin sheets 20 respectively have an outer base end portion (outer end portion) 20a on a radial direction D3 orthogonal to the axis AX of the rotating shaft 52, an inner front end portion (inner end portion) 20b, side edges 20c on both axial sides of the rotating shaft 52 that are close to the high-pressure space, and side edges 20d on both axial sides of the rotating shaft 52 that are close to the low-pressure space.

[0063] In the following description, the base ends 20a of the plurality of sheets 20 are collectively referred to as the base end 12a of the sheet stack 12, the front ends 20b of the plurality of sheets 20 are collectively referred to as the front end 12b of the sheet stack 12, the side ends 20c of the plurality of sheets 20 are collectively referred to as the side end 12c of the sheet stack 12, and the side ends 20d of the plurality of sheets 20 are collectively referred to as the side end 12d of the sheet stack 12. The base end 12a is the aggregate of the plurality of base ends 20a. The front end 12b is the aggregate of the plurality of front ends 20b. The side end 12c is the aggregate of the plurality of side ends 20c. The side end 12d is the aggregate of the plurality of side ends 20d.

[0064] The base end portion 12a faces outward in the radial direction D3 of the rotating shaft 52. The front end portion 12b faces inward in the radial direction D3 of the rotating shaft 52, so as to be opposed to the outer peripheral surface 52a of the rotating shaft 52. In addition, the front end portion 12b (front end portion 20b) is arranged on the outside of the recessed portion 9a via the opening 9k. It should be noted that the front end portion 12b (front end portion 20b) is arranged on the outside of the seal mounting groove 31 described in detail below. The side end portion 12c faces the other side in the axial direction D1 of the rotating shaft 52, that is, the high-pressure space. The side end portion 12d faces one side in the axial direction D1 of the rotating shaft 52, that is, the low-pressure space.

[0065] In this embodiment, the base ends 20a of the plurality of sheets 20 are fixed to the sealing ring 30 as described below, serving as fixed ends. Furthermore, the leading ends 20b of the plurality of sheets 20 serve as free ends that are not fixed. The plurality of sheets 20 (sheet stack 12) are held by the sealing ring 30 with the base ends 20a fixed.

[0066] The sheet 20 includes a head portion 21 having a base end 20a and a main body portion 22 having a front end 20b, side ends 20c, and side ends 20d, and is elastically deformable. The main body portion 22 is smaller than the head portion 21 in the axial direction D1 of the rotating shaft 52, i.e., in the width direction of the sheet 20. The main body portion 22 is smaller than the head portion 21 in the thickness direction of the sheet 20. The main body portion 22 is provided with a cutout 20x and a cutout 20y at the boundary between the main body portion 22 and the head portion 21. The head portion 21 protrudes in the width direction relative to the cutouts 20x and 20y, respectively, closer to the base end 20a. In this embodiment, the plurality of sheets 20 are connected to each other by welding at the ends (base end 20a) outside the radial direction D3 of the head portion 21 and the side ends 21c and 21d of the head portion 21 in the axial direction D1.

[0067] (Side panel 41)

[0068] In this embodiment, the side plate 41 is a thin, arc-shaped plate extending in the circumferential direction D2. The normal to the surface of the side plate 41 extends in the axial direction D1. That is, the thickness direction of the side plate 41 is substantially aligned with the axial direction D1 of the rotating shaft 52. The side plate 41 extends in the circumferential direction D2 from one end of the seal segment 11 to the other end of the seal segment 11 in the circumferential direction D2.

[0069] The side plate 41 is disposed within the seal mounting groove 31 adjacent to the side end 20c of the fin 20 facing the high-pressure space. The surface of the side plate 41 on one side (low-pressure space side) in the axial direction D1 faces the side end 20c of the fin 20 facing the high-pressure space.

[0070] (Sealing ring 30)

[0071] In this embodiment, the seal ring 30 is supported by the housing 9 and holds the sheet stack 12. The housing 9 has a holding portion 9s that holds the seal ring 30 inside the recess 9a. The seal ring 30 is held by the holding portion 9s.

[0072] exist Figure 3 In the shaft sealing device 10 of the illustrated embodiment, the seal ring 30 is a single integrally formed member.

[0073] exist Figure 4 In the shaft sealing device 10 of another embodiment shown in FIG, the seal ring 30 includes two components: a low-pressure side seal ring (first component) 301 and a high-pressure side seal ring (second component) 302. Figure 4 In the shaft sealing device 10 of the other embodiment shown, as described above, the low-pressure side seal ring 301 and the high-pressure side seal ring 302 are coupled and integrally fixed by the fastening bolts 48 .

[0074] exist Figure 3 and Figure 4 The seal ring 30 shown has a seal mounting groove 31 for mounting a plurality of slices 20. The seal mounting groove 31 includes a first groove portion 33 for receiving the head portion 21 of the slice 20 and a second groove portion 34 for receiving the body portion 22 of the slice 20.

[0075] The dimension of the first groove 33 in the axial direction D1 is larger than the dimension of the second groove 34 in the axial direction D1. Therefore, a step 35 is formed at the boundary between the first groove 33 and the second groove 34. A surface 35a of the step 35 facing outward in the radial direction D3 abuts against an end 21e inward in the radial direction D3 of the head 21 of the sheet 20, thereby restricting movement of the sheet 20 inward in the radial direction D3 relative to the seal ring 30.

[0076] exist Figure 3 In the illustrated embodiment, a pressing bolt 45 is mounted in a region outside the first groove 33 of the seal ring 30 in the radial direction D3. The pressing bolt 45 presses the coil spring 43 from the outside in the radial direction D3 to apply a compressive force to the coil spring 43, which in turn urges the head 21 of the sheet 20 inward in the radial direction D3.

[0077] Therefore, in Figure 3 In the embodiment shown, the head portion 21 of the sheet 20 is urged inward in the radial direction D3 .

[0078] exist Figure 4 In the embodiment shown, the seal ring 30 is divided into a low-pressure side seal ring 301 and a high-pressure side seal ring 302 between the inner wall 33a on one side (low-pressure space side) and the inner wall 33b on the other side (high-pressure space side) of the first groove portion 33 in the axial direction D1, at a position closer to the other side (high-pressure space side) than the middle position of the inner walls 33a and 33b in the axial direction D1. Figure 4 In the embodiment shown, the dividing position 303 of the low-pressure side sealing ring 301 and the high-pressure side sealing ring 302 (the abutment position of the low-pressure side sealing ring 301 and the high-pressure side sealing ring 302) is near the inner wall 33a on the side of the axial direction D1 relative to the center position of the axial direction D1 of the thin film 20.

[0079] exist Figure 4 In the illustrated embodiment, a shim 47 is disposed in an area outside the first groove 33 of the seal ring 30 in the radial direction D3, that is, in an area outside the first groove 33 of the low-pressure side seal ring 301 in the radial direction D3. The shim 47 is disposed in the gap between the inner wall 33c of the first groove 33, which faces inward in the radial direction D3, and the base end 20a of the sheet 20. The shim 47 is a member for securing the head 21 of the sheet 20 so that the surface 35a of the step 35 and the end 21e of the head 21 of the sheet 20 do not separate in the radial direction D3.

[0080] Therefore, in Figure 4 In the illustrated embodiment, the head portion 21 of the sheet 20 is restricted from moving outward in the radial direction D3 .

[0081] It should be noted that in Figure 4 In the shaft sealing device 10 of another embodiment shown, a coil spring 43 may be provided instead of the shim 47 .

[0082] exist Figure 3 and Figure 4 In the seal ring 30 shown, the inner wall 34a on one side (low-pressure space side) and the inner wall 34b on the other side (high-pressure space side) of the second groove portion 34 of the seal mounting groove 31 in the axial direction D1 are spaced apart and opposed to each other along the axial direction D1.

[0083] It should be noted that in Figure 4 In the illustrated embodiment, the inner wall 34 a on one side in the axial direction D1 is formed on the low-pressure side seal ring 301 , and the inner wall 34 b on the other side is formed on the high-pressure side seal ring 302 .

[0084] exist Figure 3 and Figure 4 In the seal ring 30 shown, during operation of the turbine 4, the pressure difference between the high-pressure space and the low-pressure space of the combustion gas G3 causes the fins 20 and side plates 41 to be biased toward the low-pressure space. Consequently, during operation of the turbine 4, the side ends 20d of the fins 20 are pressed against the inner wall 34a.

[0085] It should be noted that during operation of the turbine 4 , a gap is generated between the surface of the side plate 41 facing the high-pressure side space and the inner wall 34 b of the seal mounting groove 31 .

[0086] Figure 7 1 is a schematic cross-sectional view schematically showing a conventional shaft sealing device including a plurality of fins 20 , and shows a cross section including the axis AX of the rotating shaft 52 .

[0087] Figure 7 The conventional shaft sealing device 10X shown includes a plurality of seal segments arranged around the rotating shaft 52 , similarly to the shaft sealing device 10 according to the present embodiment described above.

[0088] exist Figure 7 In the conventional shaft sealing device 10X shown, each seal segment includes a plurality of thin sheets (plates) 20 arranged around a rotating shaft 52 and a high-pressure side plate 41 , similarly to the shaft sealing device 10 of the present embodiment described above.

[0089] In addition, Figure 7In the conventional shaft sealing device 10X shown, each seal segment includes a seal ring 30X having a groove 31X for mounting a plurality of lamellae 20, a pair of lamellae seal holders (retaining rings) 91 and 92 for holding the lamellae 20, a low-pressure-side side plate 42, and a leaf spring 93. Furthermore, the conventional shaft sealing device 10X includes a mounting part 95 that is disposed within the groove 31X formed in the seal ring 30X along with these components.

[0090] exist Figure 7 In the conventional shaft sealing device 10X shown, a pair of disk seal holders 91 and 92 sandwich the head portion 21 of the disk 20 from one side and the other side in the axial direction D1.

[0091] exist Figure 7 In the conventional shaft seal device 10X shown, the side plate 42 is a thin, arcuate plate extending in the circumferential direction D2. The thickness of the side plate 42 is substantially aligned with the axial direction D1 of the rotating shaft 52. The side plate 42 extends from one end of each seal segment in the circumferential direction D2 to the other end of the seal segment in the circumferential direction D2.

[0092] The side plate 42 is disposed in the groove 31X adjacent to the side end 20d of the sheet 20 facing the low-pressure space. The side plate 42 is sandwiched between the side end 20d of the sheet 20 and the side surface 95a of the mounting member 95 facing the high-pressure space.

[0093] The end 42a on the inner side of the side plate 42 in the radial direction D3 is located further outward in the radial direction D3 than the front end (inner end) 20b on the inner side of the sheet 20 and the end 95b on the inner side of the mounting fixture 95 in the radial direction D3. Therefore, a gap Sx corresponding to the thickness of the side plate 42 is formed between the side end 20d of the sheet 20 and the side surface 95a of the mounting fixture 95 at a position further inward in the radial direction D3 than the end 42a on the inner side of the side plate 42 in the radial direction D3. This gap Sx, similar to the groove 36 described below, serves to ensure buoyancy for the sheet 20.

[0094] exist Figure 7 In the conventional shaft sealing device 10X shown, the leaf spring 93 is used to bias the head portion 21 of the sheet 20 inward in the radial direction D3.

[0095] Relative to Figure 7 The conventional shaft sealing device 10X shown can omit the pair of sheet seal holders 91 and 92, the side plate 42, and the mounting parts 95 according to the shaft sealing device 10 of the aforementioned embodiments. This can reduce the cost of the shaft sealing device 10.

[0096] Furthermore, in a rotary machine including the shaft sealing device 10 according to the above-described embodiments, leakage of the working fluid in the shaft sealing device 10 can be suppressed, and the cost of the rotary machine can be reduced.

[0097] In the shaft sealing device 10 of this embodiment, as shown in FIG. Figure 3 As in the illustrated embodiment, the inner wall 34a on one side (low-pressure space side) and the inner wall 34b on the other side (high-pressure space side) of the seal mounting groove 31 in the axial direction D1 may be formed by the same member.

[0098] Thus, compared with a case where the inner wall 34 a on one side and the inner wall 34 b on the other side are formed in different members, the number of components can be reduced, and the assembly cost can also be reduced.

[0099] In addition, in the shaft sealing device 10 of this embodiment, as Figure 4 As in the illustrated embodiment, the inner wall 34 a on one side and the inner wall 34 b on the other side of the seal mounting groove 31 in the axial direction D1 may be formed in different members.

[0100] Because the tab 20 protrudes from the inner end of the seal mounting groove 31 in radial direction D3 toward the inner side of radial direction D3, the seal ring 30 opens inward in radial direction D3. Therefore, if the inner wall 34a on one side and the inner wall 34b on the other side of the seal mounting groove 31 are formed from the same member, the seal mounting groove 31 is formed by cutting from the inner side in radial direction D3. However, the radial dimension D3 of the seal mounting groove 31 is larger than the axial dimension D1. Therefore, the area outside the radial direction D3 of the seal mounting groove 31 (e.g., the first groove portion 33) is more difficult to cut than the area inside the radial direction D3 (e.g., the second groove portion 34). As described above, the axial dimension D1 of the first groove portion 33 is larger than the axial dimension D1 of the second groove portion 34. Therefore, it is difficult to access the first groove portion 33 from the inner side in radial direction D3 and cut it.

[0101] like Figure 4 As in the illustrated embodiment, by forming the inner wall 34a on one side of the seal mounting groove 31 and the inner wall 34b on the other side of the seal mounting groove 31 in separate members, the outer region in the radial direction D3 of the seal mounting groove 31 can also be easily machined. This makes it easier to ensure the accuracy of the seal mounting groove 31, thereby reducing the amount of fluid leakage in the shaft sealing device 10.

[0102] In the shaft sealing device 10 of this embodiment, as shown in FIG. Figure 4As in the illustrated embodiment, the low-pressure side seal ring (first member) 301 and the high-pressure side seal ring (second member) 302 may also be integrally fixed. The contact position (dividing position 303) between the low-pressure side seal ring 301 and the high-pressure side seal ring 302 is preferably offset to one side in the axial direction D1 relative to the center position of the thin slice 20 in the axial direction D1. It should be noted that the contact position (dividing position 303) between the low-pressure side seal ring 301 and the high-pressure side seal ring 302 may also be offset to the other side in the axial direction D1 relative to the center position of the thin slice 20 in the axial direction D1.

[0103] Consider the following situation: when assembling the shaft sealing device 10, before combining the low-pressure side sealing ring 301 with the high-pressure side sealing ring 302, a thin film 20 is arranged on the components of either the low-pressure side sealing ring 301 or the high-pressure side sealing ring 302, and then the components of the other side are combined with the components of one side.

[0104] For example, Figure 4 As shown, if the split point 303 is offset to the other side so as to approach the high-pressure space, the length along the axial direction D1 of the portion of the low-pressure side seal ring 301 where the end surface corresponding to the split point 303 is formed (the portion where the inner wall 33c is formed) is longer than the same portion of the high-pressure side seal ring 302. Therefore, when the sheet 20 is assembled to the seal ring 30, by positioning the sheet 20 from above with the low-pressure side seal ring 301 at the bottom, the portion of the low-pressure side seal ring 301 where the end surface corresponding to the split point 303 is formed (the portion where the inner wall 33c is formed) functions as a guide for the sheet 20, facilitating the positioning of the sheet 20.

[0105] In addition, if Figure 4 As in the illustrated embodiment, it is easy to arrange the shim 47 in the gap between the portion where the end surface corresponding to the dividing position 303 is formed (the portion where the inner wall 33 c is formed) and the base end portion 20 a of the sheet 20 .

[0106] Similarly, for example, if the split position 303 is offset to one side so as to approach the low-pressure space, the axial length of the portion of the high-pressure side seal ring 302 where the end surface corresponding to the split position 303 is formed is longer than the same portion of the low-pressure side seal ring 301. Therefore, when the sheet 20 is assembled to the seal ring 30, the sheet 20 and the shim 47 are positioned from above with the high-pressure side seal ring 302 positioned downward, thereby facilitating the positioning of the sheet 20 and the shim 47.

[0107] It should be noted that, in the shaft sealing device 10 of this embodiment, Figure 4 As in the illustrated embodiment, the dividing position 303 is preferably offset in a direction away from the groove 36 along the axial direction D1 relative to the center position of the sheet 20 in the axial direction D1.

[0108] The shaft seal device 10 of this embodiment is arranged in a rotating machine such that the groove 36 is located in the region (low-pressure space) on the low-pressure side across the shaft seal device 10. Furthermore, in the shaft seal device 10 of this embodiment, a side plate 41 extending in the circumferential direction D2 is arranged so as to contact the side end portions 20c of the two side edges of the lamella 20 that face the high-pressure space across the shaft seal device 10. Therefore, when assembling the shaft seal device 10, arranging the side plate 41 above the lamella 20 facilitates assembly. In this case, the low-pressure side seal ring 301 having the groove 36 is positioned below, the lamella 20 is positioned from above, and the side plate 41 is positioned above it. Therefore, if the split point 303 is offset from the aforementioned center position toward the other side closer to the high-pressure space, the length along the axial direction D1 of the portion of the low-pressure side seal ring 301 where the end surface corresponding to the split point 303 is formed is longer than the same portion of the high-pressure side seal ring 302.

[0109] If the divided position 303 is offset from the center position in the axial direction D1 in a direction away from the groove 36 , the divided position 303 is offset to the other side from the center position, thereby facilitating assembly of the shaft sealing device 10 having the side plate 41 .

[0110] (Regarding slot 36)

[0111] exist Figure 3 and Figure 4 In the illustrated seal ring 30 , an inner wall 34 a of the seal mounting groove 31 on one side in the axial direction D1 has a groove 36 formed along the circumferential direction D2 in an area on the inner side in the radial direction D3 .

[0112] Figure 5 is equivalent to Figure 3 The cross-sectional view taken along the line VV shows only the sealing ring 30 .

[0113] Figure 6A yes Figure 5 The cross-sectional view taken along the line VI-VI shows an example of the groove 36 .

[0114] Figure 6B yes Figure 5 The cross-sectional view taken along the line VI-VI shows another example of the groove 36 .

[0115] It should be noted that in Figure 3 The sealing ring 30 and Figure 4 In the sealing ring 30 shown, the groove 36 has the same shape, so based on the equivalent Figure 3 The cross-sectional view of the VV direction is Figure 5 ,as well as Figure 6A 、 Figure 6B, the shape of the groove 36 will be described.

[0116] For the convenience of explanation, Figure 5 In the figure, two seal segment bodies 11 adjacent to each other in the circumferential direction D2 are shown as being separated in the circumferential direction D2 . However, during operation of the turbine 4 , there is almost no gap between the two seal segment bodies 11 adjacent to each other in the circumferential direction D2 .

[0117] exist Figure 6A and Figure 6B In FIG. 1 , two seal segment bodies 11 adjacent to each other in the circumferential direction D2 are shown in the figure so as to abut against each other in the circumferential direction D2 .

[0118] exist Figure 5 、 Figure 6A and Figure 6B , one of two seal segment bodies 11 adjacent to each other in the circumferential direction D2 , namely, the first segment body 11A, and the other, namely, the second segment body 11B, are shown.

[0119] exist Figure 3 and Figure 4 In the sealing ring 30 of the present embodiment shown in FIG. Figure 5 、 Figure 6A and Figure 6B As shown, the groove 36 in the first segment body 11A and the second segment body 11B includes: a first area 361, whose depth in the axial direction D1 has a first depth d1; and a second area 362, which is closer to the end surface 11e of the first segment body 11A and the second segment body 11B in the circumferential direction D2 than the first area d1 and has a second depth d2 deeper than the first depth d1.

[0120] Near the end faces 11e of the circumferentially adjacent first and second segments 11A and 11B, i.e., near the circumferential division point of the seal ring 30, the upward buoyancy of the sheet 20 tends to decrease, causing the sheet 20 to contact the rotating shaft 52. It is known that, on the leading end side (radially inner side) of the sheet 20, the upward buoyancy of the sheet 20 increases as the distance between the end 20d of the two end portions 20c and 20d of the sheet 20, which is closer to the low-pressure space, and the member (seal ring 30) facing the end 20d increases.

[0121] according to Figure 3 and Figure 4 The sealing ring 30 of the present embodiment shown in the figure can ensure the buoyancy of the sheet 20 and suppress the contact between the sheet 20 and the rotating shaft 52 by providing the above-mentioned second area 362 near the circumferential division position of the sealing ring 30 where the buoyancy of the sheet 20 is easily reduced.

[0122] exist Figure 3 and Figure 4In the sealing ring 30 of the present embodiment shown in FIG. Figure 6A As shown, the second depth d2 of the second region 362 is constant regardless of the position in the circumferential direction D2 of the second region 362. Therefore, compared with a case where the second depth d2 varies depending on the position in the circumferential direction D2 of the second region 362, machining of the second region 362 is facilitated.

[0123] In addition, Figure 3 and Figure 4 In the sealing ring 30 of the present embodiment shown in FIG. Figure 6B As shown, the second depth d2 of the second region 362 becomes deeper as it approaches the end surface 11e.

[0124] The closer to the circumferential division position of the seal ring 30 (the end surface 11 e ), the more easily the buoyancy of the sheet 20 is reduced.

[0125] like Figure 6B As shown, the second depth d2 increases as the position of the circumferential direction D2 in the second region 362 approaches the end surface 11e, thereby suppressing the decrease in the buoyancy of the sheet 20 as it approaches the end surface 11e and suppressing the contact between the sheet 20 and the rotating shaft 52.

[0126] exist Figure 3 and Figure 4 In the seal ring 30 of the present embodiment shown, the first depth d1 is, for example, not less than 0.15 mm and not more than 0.30 mm, and the second depth d2 is greater than the first depth d1 and, for example, not less than 0.35 mm and not more than 0.60 mm. It should be noted that in the circumferentially adjacent first and second segments 11A, 11B, the second depth d2 is preferably the same in each of the two second regions 362 adjacent to each other across the end surface 11 e.

[0127] In at least a portion of the second region 362 , the second depth d2 is greater than the first depth d1 , and may be three times or less of the first depth d1 , and preferably approximately twice of the first depth d1 .

[0128] It should be noted that if Figure 6B As shown in FIG. 1 , when the second depth d2 becomes deeper as it approaches the end surface 11 e , it is preferable that the second depth d2 at a position in the circumferential direction D2 very close to the end surface 11 e be within the above-mentioned range.

[0129] To ensure sufficient buoyancy for the sheet 20 near the end surface 11e, the second depth is preferably greater than the first depth d1 in at least a portion of the second region 362. Furthermore, even if the second depth d2 exceeds three times the first depth d1, the buoyancy of the sheet 20 near the end surface 11e remains essentially unchanged compared to when the second depth d2 is three times the first depth d1. Therefore, even if the second depth d2 exceeds three times the first depth d1, the machining effort (cutting distance) required to ensure the second depth d2 is increased.

[0130] According to the above-described configuration, it is possible to effectively ensure the buoyancy of the sheet 20 in the vicinity of the end surface 11 e.

[0131] In the case of an industrial gas turbine, the width W1 of the groove 36 (see Figure 5 ), that is, the radial size D3 of the first area 361 and the second area 362 is approximately 5.5 mm.

[0132] In addition, in the case of an industrial gas turbine, the length of the second region 362 in the circumferential direction D2 is approximately 50 mm.

[0133] The present disclosure is not limited to the above-described embodiment, and also includes forms obtained by adding modifications to the above-described embodiment and forms obtained by appropriately combining these forms.

[0134] The contents described in each of the above-mentioned embodiments can be understood, for example, as follows.

[0135] (1) A shaft sealing device 10 according to at least one embodiment of the present disclosure includes: a plurality of thin plates (sheets 20) arranged along the circumferential direction D2 of a rotating shaft 52 (rotating shaft 50) and having a width in the axial direction D1 of the rotating shaft 52 (rotating shaft 50); and a seal ring 30 including a seal mounting groove 31 for mounting the plurality of thin plates (sheets 20). An inner wall 34a of the seal mounting groove 31 on one side in the axial direction D1 includes a groove 36 formed along the circumferential direction D2 in a region inward in the radial direction D3 of the rotating shaft 52 (rotating shaft 50).

[0136] According to the configuration (1), the pair of sheet seal holders provided in conventional shaft sealing devices, the annular plate disposed on one side (low-pressure space side) in the axial direction D1, and mounting parts can be omitted, thereby reducing the cost of the shaft sealing device 10.

[0137] (2) In some embodiments, in addition to the structure of (1) above, the seal ring 30 includes at least a first segment 11A and a second segment 11B that are divided in the circumferential direction D2. Preferably, the groove 36 in the first segment 11A and the second segment 11B includes a first region 361 having a first depth d1 in the axial direction D1, and a second region 362 that is closer to the end surface 11e of the first segment 11A and the second segment 11B in the circumferential direction D2 than the first region 361 and has a second depth d2 that is deeper than the first depth d1.

[0138] According to the structure of (2) above, by setting the above-mentioned second area 362, the buoyancy of the sheet 20 can be ensured near the circumferential division position of the sealing ring 30 where the buoyancy of the sheet 20 is easily reduced, thereby suppressing the contact between the sheet 20 and the rotating shaft 52 (rotating shaft 50).

[0139] (3) In some embodiments, in addition to the configuration of (2) above, it is preferred that the second depth d2 becomes deeper as it approaches the end surface 11 e .

[0140] The buoyancy of the sheet 20 is more likely to decrease as it approaches the circumferential division position (end surface 11 e ) of the seal ring 30 .

[0141] According to the configuration of (3), by increasing the second depth d2 as the sheet approaches the end surface 11e, it is possible to suppress a decrease in the buoyancy of the sheet 20 as the sheet approaches the end surface 11e, thereby suppressing contact between the sheet 20 and the rotating shaft 52 (rotating shaft 50).

[0142] (4) In some embodiments, based on the structure of (2) or (3) above, it is preferred that the second depth d2 is greater than the first depth d1 in at least a portion of the second region 362 and is less than or equal to three times the first depth d1.

[0143] According to the configuration of (4) above, it is possible to effectively ensure the buoyancy of the sheet 20 in the vicinity of the circumferential division position of the seal ring 30 .

[0144] (5) In some embodiments, based on any one of the structures (1) to (4) above, it is preferred that the inner wall 34a on the one side and the inner wall 34b on the other side of the seal mounting groove 31 in the axial direction D1 are formed in the same member.

[0145] According to the configuration of (5) above, compared with a case where the inner wall 34 a on one side and the inner wall 34 b on the other side are formed in different members, the number of components can be reduced and the assembly cost can also be reduced.

[0146] (6) In some embodiments, based on any of the structures (1) to (4) above, the inner wall 34a on one side of the seal mounting groove 31 in the axial direction D1 and the inner wall 34b on the other side may be formed in different components.

[0147] According to the configuration (6) above, by forming the inner wall 34a on one side of the seal mounting groove 31 and the inner wall 34b on the other side in separate members, the outer region of the seal mounting groove 31 in the radial direction D3 can also be easily machined. This makes it easier to ensure the accuracy of the seal mounting groove 31, thereby reducing the amount of fluid leakage in the shaft sealing device 10.

[0148] (7) In some embodiments, in addition to the structure of (6), the seal ring 30 preferably includes a first member (low-pressure side seal ring 301) having an inner wall 34a on one side and a second member (high-pressure side seal ring 302) having an inner wall 34b on the other side, wherein the first member (low-pressure side seal ring 301) and the second member (high-pressure side seal ring 302) are integrally fixed. Preferably, the contact position (dividing position 303) between the first member (low-pressure side seal ring 301) and the second member (high-pressure side seal ring 302) is offset from the center position of the thin plate (sheet 20) in the axial direction D1 to one of the one side and the other side in the axial direction D1.

[0149] According to the structure of (7) above, when assembling the shaft sealing device 10, it is easy to position the sheet 20.

[0150] (8) In some embodiments, based on the structure of (7), the contact position (dividing position 303 ) may be offset in a direction away from the groove 36 along the axial direction D1 relative to the center position.

[0151] According to the configuration of (8), the contact position (dividing position 303 ) is offset to the other side from the center position, and thus the shaft sealing device 10 having the side plate 41 can be easily assembled.

[0152] (9) The rotary machine (compressor 2, turbine 4) of at least one embodiment of the present disclosure includes: a rotary shaft 50 (rotating shaft 51, rotating shaft 52); and a shaft sealing device 10 having any one of the structures described in (1) to (8).

[0153] According to the configuration of (9) above, it is possible to suppress leakage of the working fluid in the shaft sealing device 10 and to reduce the cost of the rotary machine (the compressor 2 and the turbine 4).

[0154] Description of reference numerals:

[0155] 1...Gas turbine system;

[0156] 2...Compressor (rotating machinery);

[0157] 4...Turbine (rotating machinery);

[0158] 10...Shaft sealing device;

[0159] 11...seal segment body;

[0160] 11A... first segment body;

[0161] 11B...Second segment body;

[0162] 11e...end face;

[0163] 20... thin sheet (sheet);

[0164] 30...Sealing ring;

[0165] 31...Seal mounting groove;

[0166] 34a, 34b...inner wall;

[0167] 41...Side panel (high-voltage side panel);

[0168] 50, 51, 52...rotation axis;

[0169] 301: low-pressure side sealing ring (first component);

[0170] 302: high-pressure side sealing ring (second component);

[0171] 303...Split location.

Claims

1. A shaft sealing device, wherein: The shaft sealing device comprises: a plurality of thin plates arranged in a circumferential direction of the rotating shaft and having a width in an axial direction of the rotating shaft; and a sealing ring comprising a seal mounting groove for mounting the plurality of thin plates, The inner wall of the seal mounting groove on one side in the axial direction has a groove formed along the circumferential direction in a region radially inside the rotating shaft. The sealing ring at least includes a first segment body and a second segment body which are divided in the circumferential direction. The grooves in the first segment body and the second segment body include: a first region having a first depth in the axial direction; and a second region closer to the circumferential end surface of the first segment body and the second segment body than the first region, having a second depth deeper than the first depth.

2. The shaft sealing device according to claim 1, wherein: The second depth becomes deeper as approaching the end surface.

3. The shaft sealing device according to claim 1 or 2, wherein: The second depth is greater than the first depth in at least a portion of the second region and is three times or less of the first depth.

4. The shaft sealing device according to claim 1 or 2, wherein: An inner wall on one side and an inner wall on the other side of the seal installation groove in the axial direction are formed on the same member.

5. The shaft sealing device according to claim 1 or 2, wherein: An inner wall on one side and an inner wall on the other side of the seal installation groove in the axial direction are formed in different members.

6. The shaft sealing device according to claim 5, wherein: The sealing ring includes a first member forming an inner wall on one side and a second member forming an inner wall on the other side, wherein the first member and the second member are fixed integrally. The contact position between the first member and the second member is offset from the center position of the thin plate in the axial direction to one of one side and the other side in the axial direction.

7. The shaft sealing device according to claim 6, wherein: The abutment position is offset from the center position in a direction away from the groove along the axial direction.

8. A rotating machine, wherein: The rotating machine comprises: The shaft sealing device according to any one of claims 1 to 3; and The rotation axis.

Images