Stator vane segment of compressor and compressor

Abstract

To reduce vibration of stator vanes in a stator vane segment of a compressor.SOLUTION: A stator vane segment of a compressor according to at least one embodiment of the disclosure includes: a plurality of stator vanes disposed in a circumferential direction; a holder attached to inner shrouds of the stator vanes; and a spring member which is disposed between the respective inner shrouds and the holder, extends in the circumferential direction, and applies the biasing force so as to separate the respective inner shrouds and the holder from each other in a radial direction. Each of the stator vanes has a recessed part enclosed at an entire periphery by an inner shroud body and recessed to the radial outer side at the radial inner side of the inner shroud body of the inner shroud. The spring member contacts with the inner shroud body at a position which is not provided with the recessed part to bias the inner shroud to the radial outer side.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a compressor stator vane segment and a compressor. [Background technology]

[0002] A gas turbine includes a compressor that compresses outside air to generate compressed air, a combustor that mixes fuel with the compressed air and burns it to generate combustion gas, and a turbine that is driven by the combustion gas.

[0003] Both the compressor and the rotor are axial flow fluid machines and include a rotor that rotates about a rotation axis and a casing that covers the rotor. The rotor has a rotor body that extends in an axial direction parallel to the rotation axis, and a plurality of rotor blade stages that are fixed to the outer periphery of the rotor body and arranged in the axial direction. A stator vane stage is fixed to the inner periphery of the casing at a position upstream of each rotor blade stage. One stator vane stage forms a stator vane ring in which a plurality of stator vanes are arranged in the circumferential direction and connected to each other. For assembly convenience, this stator vane ring is divided in the circumferential direction. Each of these circumferentially divided parts is generally called a stator vane segment. This stator vane segment is formed by connecting a plurality of stator vanes in the circumferential direction (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2013 / 146590 Summary of the Invention [Problem to be solved by the invention]

[0005] In the above-described stator vane segment, the outer shrouds are connected to each other by an outer connecting member, and the inner shrouds are connected to each other by an inner connecting member. Since the outer peripheral portion of the stator vane segment is attached to the casing of the compressor, the inner shroud side is more likely to vibrate than the outer shroud side.

[0006] This may result in problems such as wear caused by the side surfaces of the inner shrouds that are adjacent in the circumferential direction rubbing against each other, or an increase in vibration stress.

[0007] In view of the above, at least one embodiment of the present disclosure aims to reduce vibration of stator vanes in a stator vane segment of a compressor. [Means for solving the problem]

[0008] (1) A compressor vane segment according to at least one embodiment of the present disclosure comprises: A compressor stator vane segment, comprising: a plurality of stator vanes arranged in a circumferential direction; a holder attached to inner shrouds of the plurality of stator vanes; a spring member disposed between each of the inner shrouds and the holder, extending in the circumferential direction, and applying a biasing force to separate each of the inner shrouds and the holder in the radial direction; Equipped with each of the plurality of stator vanes has a recessed portion that is recessed radially outward and whose entire periphery is surrounded by the inner shroud body, on the radially inner side of an inner shroud body of the inner shroud; The spring member abuts against the inner shroud body at a position where the recess is not provided, and urges the inner shroud outward in the radial direction.

[0009] (2) A compressor according to at least one embodiment of the present disclosure includes: a stator blade ring in which a plurality of stator blade segments having the configuration (1) above are arranged in the circumferential direction; Equipped with. [Effects of the Invention]

[0010] At least one embodiment of the present disclosure provides for reduced vane vibration in a compressor vane segment. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic configuration diagram of a gas turbine according to an embodiment. [Figure 2] 1 is a front view of a stator blade stage (stator blade ring) according to one embodiment. [Figure 3] FIG. 2 is a perspective view of a stator vane segment according to an embodiment. [Figure 4] FIG. 2 is a perspective view of an inner shroud according to an embodiment. [Figure 5A] FIG. 2 is a schematic diagram of an inner shroud according to an embodiment, as viewed from the radially inner side. [Figure 5B] FIG. 2 is a schematic diagram of an inner shroud according to an embodiment, as viewed from the radially inner side. [Figure 6] FIG. 4 is a schematic diagram for explaining the circumferential arrangement of inner shrouds according to one embodiment. [Figure 7A] FIG. 5B is a cross-sectional view taken along the arrow AA in FIG. 5A. [Figure 7B] FIG. 5C is a cross-sectional view taken along the arrow AA in FIG. 5B. [Figure 8] FIG. 8 is a cross-sectional view of an outer shroud according to one embodiment taken along the line VIII in FIG. 3 . [Figure 9A] 4 is a schematic cross-sectional view of a first inner shroud and a connection holder according to one embodiment, as viewed from the circumferential direction. FIG. [Figure 9B] FIG. 4 is a schematic cross-sectional view of a second inner shroud and a connection holder according to one embodiment, as viewed from the circumferential direction. [Figure 10A] FIG. 9B is a cross-sectional view taken along the arrow CC in FIG. 9A. [Figure 10B] FIG. 9B is a cross-sectional view taken along the arrow DD in FIG. 9A. [Figure 11A] FIG. 10 is a schematic view of an inner shroud according to another embodiment, as viewed from the radially inner side. [Figure 11B] FIG. 10 is a schematic view of an inner shroud according to another embodiment, as viewed from the radially inner side. [Figure 12] FIG. 10 is a schematic view of an inner shroud according to another embodiment, as viewed from the radially inner side. [Figure 13]FIG. 10 is a perspective view of an inner shroud according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[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. For example, expressions expressing relative or absolute arrangement such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial" not only express such an arrangement exactly, 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 such as "identical," "equal," and "homogeneous" that indicate that something is in an equal state not only indicate a state of strict equality, but also indicate a state in which there is a tolerance or a difference to the extent that the same function is obtained. For example, expressions representing shapes such as a square shape or a cylindrical shape not only represent shapes such as a square shape or a cylindrical shape in the strict geometric sense, but also represent shapes including uneven portions, chamfered portions, etc., to the extent that the same effect can be obtained. On the other hand, the expressions "comprise," "include," "have," "includes," or "have" of one element are not exclusive expressions that exclude the presence of other elements.

[0013] Hereinafter, an embodiment of an axial flow fluid machine to which a compressor stator vane segment according to an embodiment is applied will be described in detail with reference to the drawings.

[0014] FIG. 1 is a schematic configuration diagram of a gas turbine according to one embodiment. As shown in FIG. 1, the gas turbine 100 includes a compressor 1 that compresses outside air to generate compressed air, a plurality of combustors 6 that mix fuel from a fuel supply source with the compressed air and combust it to generate combustion gas, and a turbine 7 that is driven by the combustion gas.

[0015] The compressor 1 and the turbine 7 are both axial flow fluid machines and include rotors 2 and 8 that rotate about a rotational axis Ar and casings 5 ​​and 9 that cover the rotors 2 and 8. The compressor rotor 2 and the turbine rotor 8 rotate about the same rotational axis Ar and are connected to each other. A plurality of combustors 6 are fixed to the turbine casing 9 at equal intervals in a circumferential direction Dc around the rotational axis Ar. Hereinafter, the direction in which the rotational axis Ar extends is referred to as the axial direction Da, and the radial direction relative to the rotational axis Ar is simply referred to as the radial direction Dr. In addition, in the axial direction Da, the compressor 1 side with respect to the turbine 7 is referred to as the upstream side, and the turbine 7 side with respect to the compressor 1 is referred to as the downstream side.

[0016] The compressor rotor 2 has a rotor body 3 extending in the axial direction Da, and a plurality of rotor blade stages 4 fixed to the outer periphery of the rotor body 3 and aligned in the axial direction Da. On the inner periphery side of the compressor casing 5, a stator vane stage 10 is fixed at a position upstream of each rotor blade stage 4.

[0017] FIG. 2 is a front view of a stator blade stage (stator blade ring) according to some embodiments. As shown in Fig. 2, one stator vane stage 10 is formed as a stator vane ring in which a plurality of stator vanes 20 are arranged in an annular shape and connected to one another. For the convenience of assembly, this stator vane ring is divided in the circumferential direction. Each of these circumferentially divided parts constitutes a stator vane segment 11. This stator vane segment 11 is formed by arranging some of the stator vanes 20 that make up the stator vane ring in the circumferential direction Dc and connecting them to one another.

[0018] FIG. 3 is a perspective view of a stator vane segment according to some embodiments. FIG. 4 is a perspective view of an inner shroud according to one embodiment. FIG. 5A is a schematic view of an inner shroud according to one embodiment, as viewed from the inside in the radial direction. FIG. 5B is a schematic view of the inner shroud according to one embodiment as viewed from the radially inner side. FIG. 6 is a schematic diagram for explaining the circumferential arrangement of inner shrouds according to one embodiment. FIG. 7A is a cross-sectional view taken along the line AA in FIG. 5A. FIG. 7B is a cross-sectional view taken along the line AA in FIG. 5B. FIG. 8 is a cross-sectional view of an outer shroud according to one embodiment taken along the arrow VIII in FIG. 3 . FIG. 9A is a schematic cross-sectional view of a first inner shroud and a connection holder according to one embodiment, as viewed from the circumferential direction. FIG. 9B is a schematic cross-sectional view of the second inner shroud and the connection holder according to one embodiment, as viewed from the circumferential direction. FIG. 10A is a cross-sectional view taken along the line CC in FIG. 9A. FIG. 10B is a cross-sectional view taken along the arrow DD in FIG. 9A. FIG. 11A is a schematic view of an inner shroud according to another embodiment, as viewed from the radially inner side. FIG. 11B is a schematic view of an inner shroud according to another embodiment, as viewed from the radially inner side. FIG. 12 is a schematic view of an inner shroud according to another embodiment, as viewed from the radially inner side. FIG. 13 is a perspective view of an inner shroud according to another embodiment.

[0019] As shown in FIG. 3, the stator vane segment 11 according to some embodiments has a plurality of stator vanes 20 arranged in the circumferential direction Dc, a connecting holder (inner connecting member) 40 to which the radially inner portions of the plurality of stator vanes 20 are attached, and a connecting band (outer connecting member) 50 that connects the radially outer portions of the plurality of stator vanes 20 to each other in the circumferential direction Dc.

[0020] As shown in Figures 7A, 7B, and 8, the stator vane 20 according to some embodiments has a stator vane body 21 extending in the radial direction Dr, an inner shroud 22 provided radially inside the stator vane body 21, and an outer shroud 32 provided radially outside the stator vane body 21.

[0021] (Inner shroud 22) The inner shroud 22 according to some embodiments includes a plate-shaped inner shroud body 23 provided radially inside the vane body 21 and extending in the circumferential direction Dc, an upstream leg 24 extending radially inward from an upstream portion of the inner shroud body 23, an upstream lip 25 extending upstream from a radially inner end of the upstream leg 24, a downstream leg 26 extending radially inward from a downstream portion of the inner shroud body 23, and a downstream lip 27 extending downstream from a radially inner end of the downstream leg 26. An upstream engagement groove 28 recessed downstream and extending in the circumferential direction Dc is formed between the inner shroud body 23 and the upstream lip 25. Furthermore, a downstream engagement groove 29 recessed upstream and extending in the circumferential direction Dc is formed between the inner shroud body 23 and the downstream lip 27.

[0022] 4, 7A, 7B, and 13, the thickness of the inner shroud body 23 in the radial direction Dr is larger in a region sandwiched between the upstream leg 24 and the downstream leg 26 than in regions axially upstream of the upstream leg 24 and downstream of the downstream leg 26. That is, the inner shroud body 23 in some embodiments has a plate shape stepped in the radial direction Dr. However, in some embodiments, the radial thickness Dr of the inner shroud body 23 may be the same in the region axially upstream of the upstream leg 24 and downstream of the downstream leg 26, and in the region sandwiched between the upstream leg 24 and the downstream leg 26.

[0023] The inner shroud 22 according to some embodiments has a recess 70, which will be described later, provided in the inner shroud body 23. The recess 70 will be described in detail later.

[0024] (Outer shroud 32) In some embodiments, the outer shroud 32 includes a plate-shaped shroud body 33 that is provided radially outside the vane body 21 and extends in the circumferential direction Dc, an upstream leg 34 that extends radially outward from an upstream portion of the shroud body 33, an upstream lip 35 that extends upstream from a radially outer end of the upstream leg 34, a downstream leg 36 that extends radially outward from a downstream portion of the shroud body 33, and a downstream lip 37 that extends downstream from the radially outer end of the downstream leg 36. A band groove 31 that is recessed from the radially outer side to the radially inner side and extends in the circumferential direction Dc is formed between the upstream leg 34 and the downstream leg 36. A portion of the connecting band 50 in the circumferential direction Dc fits into this band groove 31. The connecting band 50 is joined by welding or the like to the outer shrouds 32 of the stator blades 20 at least at both ends of the stator blade segment 11 in the circumferential direction Dc.

[0025] (connection holder 40) In some embodiments, the connecting holder 40 has a seal retaining portion 43 extending in the circumferential direction Dc, an upstream leg portion 44 formed along an upstream edge of the seal retaining portion 43 and extending radially outward, an upstream flange portion 45 extending downstream from a radially outer end of the upstream leg portion 44 and fitting into the upstream engagement groove 28 of the inner shroud 22, a downstream leg portion 46 formed along the downstream edge of the seal retaining portion 43 and extending radially outward, and a downstream flange portion 47 extending upstream from the radially outer end of the downstream leg portion 46 and fitting into the downstream engagement groove 29 of the inner shroud 22. A plurality of seal fins 48 extending in the circumferential direction Dc and providing a seal with the rotor body 3 ( FIG. 1 ) of the compressor rotor 2 are provided radially inside the seal retaining portion 43 at intervals in the axial direction Da. Between the upstream leg 44 and the downstream leg 46, a shroud storage groove 41 is formed, which is recessed radially inward and extends in the circumferential direction Dc. The groove bottom of this shroud storage groove 41 is formed by a seal retaining portion 43. When the multiple stator vanes 20 constituting the stator vane segment 11 are lined up in the circumferential direction Dc, the upstream leg 24, upstream lip 25, downstream leg 26, and downstream lip 27 of the inner shroud 22 of each stator vane 20 fit into this shroud storage groove 41. In some embodiments, the connecting holder 40 is attached to the inner shrouds 22 of the plurality of stator vanes 20 as described above. Note that in some embodiments, the connecting holder 40 is coupled to the inner shrouds 22 at both ends in the circumferential direction Dc of the stator vane segment 11 by, for example, a pin (not shown), and relative movement of the connecting holder 40 with respect to the inner shrouds 22 in the circumferential direction Dc is restricted.

[0026] In some embodiments, when the connecting holder 40 is attached to the inner shroud 22, a spring member accommodating portion 49 is formed that is surrounded by the radially inner surface 23a of the inner shroud body 23 of the inner shroud 22, the upstream leg 24, the downstream leg 26, and the radially outer surface 43a of the seal retaining portion 43. Moreover, the side surfaces 22s of the inner shrouds 22 adjacent to each other in the circumferential direction Dc are in contact with each other, and the side surfaces 23s of the inner shroud bodies 23 are in contact with each other.

[0027] (Overview of the spring member 60) In some embodiments, the stator vane segment 11 is provided with a spring member 60 that is arranged between each of the inner shrouds 22 and the connecting holder 40, extends in the circumferential direction Dc, and applies a biasing force to separate each of the inner shrouds 22 and the connecting holder 40 in the radial direction Dr. The spring member 60 is a leaf spring having an outer protrusion 61 that protrudes radially outward and is configured to press the radially inner surface 23a of the inner shroud main body 23 radially outward, and an inner protrusion 62 that protrudes radially inward and is configured to press the radially outer surface 43a of the seal retaining portion 43 radially inward, and the outer protrusions 61 and the inner protrusions 62 are arranged alternately in the circumferential direction Dc. The outer protrusion 61 has a curved surface shape with a center of curvature located radially inward from the outer protrusion 61, and the inner protrusion 62 has a curved surface shape with a center of curvature located radially outward from the inner protrusion. As will be described later, the spring member 60 according to one embodiment includes a first spring member 60A and a second spring member 60B.

[0028] (Vibration of the inner shroud 22) In the above-described stator vane segment 11, the multiple outer shrouds 32 are connected to each other by connecting bands 50, and the multiple inner shrouds 22 are connected to each other by connecting holders 40. Since the outer peripheral portion of the stator vane segment 11 is attached to the casing 5 of the compressor 1, the inner shroud 22 side is more likely to vibrate than the outer shroud 32 side.

[0029] Therefore, there is a risk of problems such as wear caused by the side surfaces 22s of the inner shrouds 22 adjacent to each other in the circumferential direction Dc rubbing against each other, or an increase in vibration stress.

[0030] Therefore, in the stator vane segment 11 according to some embodiments, by providing a recess 70 in the inner shroud body 23 as described below, the weight of the inner shroud 22 is reduced, the natural frequency of the stator vane 20 is increased, and the stator vane 20 is less likely to resonate during operation of the compressor 1. This reduces the vibration of the stator vane 20, making it less likely that problems caused by the vibration of the stator vane 20 will occur.

[0031] The compressor 1 according to one embodiment includes the stator vane stages 10 in which the stator vane segments 11 according to the above-described embodiments are arranged in a plurality in the circumferential direction Dc. This reduces the vibration of the stator vanes 20 in the compressor 1, making it less likely that problems will occur due to the vibration of the stator vanes 20. This improves the reliability of the compressor 1.

[0032] (Regarding the recess 70) In the stator vane segment 11 according to some embodiments, the recess 70 has a shape that is recessed radially outward and is surrounded by the inner shroud body 23 of the inner shroud 22 radially inside as shown in each drawing. That is, in the stator vane segment 11 according to some embodiments, the recess 70 is defined by a wall surface 23w that extends in the radial direction Dr in the axial direction Da and the circumferential direction Dc, and a bottom surface 23b that faces radially inward (see FIG. 4 ). The recess 70 is surrounded by the wall surface 23w all around. The outer edge of the recess 70 is located on the radially inner surface 23a of the inner shroud body 23 all around. The recess 70 is also a portion where weight has been removed to reduce the weight of the inner shroud body 23. As a result, the recess 70 is not exposed on the side surface 22s of the inner shroud 22, so that the contact state between the side surfaces 22s of adjacent inner shrouds 22 in the circumferential direction Dc is the same as the contact state between the side surfaces of conventional inner shrouds, and the risk of unintended malfunctions occurring is extremely low.

[0033] In the stator vane segment 11 according to some embodiments, the inner shroud 22 may have an upstream leg 24 and a downstream leg 26, which are two protrusions that protrude radially inward from the radially inner side of the inner shroud body 23 and are provided at a distance from each other on the upstream side and downstream side in the axial direction Da. The recess 70 is located between the two protrusions (the upstream leg 24 and the downstream leg 26). Since the area between the two protrusions (upstream leg 24 and downstream leg 26) in the inner shroud body 23 is relatively large, it is easy to provide the recess 70, it is easy to ensure the amount of thinning caused by the recess 70, and the position of the recess 70 in that area is relatively loosely restricted.

[0034] In some embodiments of the vane segment 11, the recess 70 is provided in the inner shroud body 23 between the upstream leg 24 and the downstream leg 26, at a position closer to the upstream or downstream side in the axial direction Da. In the following description, the recess 70 provided in the inner shroud main body 23 between the upstream leg 24 and the downstream leg 26 at a position closer to the upstream side in the axial direction Da, as shown in Figures 4, 5A, 6, 7A, 9A, 10A, and 13, will be referred to as a first recess 70A. In the following description, the recess 70 provided in the inner shroud main body 23 between the upstream leg 24 and the downstream leg 26 at a position closer to the downstream side in the axial direction Da, as shown in Figures 5B, 6, 7B, 9B, and 10B, will be referred to as a second recess 70B. Note that when the first recess 70A and the second recess 70B are referred to collectively or when it is not necessary to distinguish between the first recess 70A and the second recess 70B, they will be simply referred to as recess 70.

[0035] In the following description, the inner shroud 22 provided with the first recess 70A will be referred to as the first inner shroud 22A. In the following description, the inner shroud 22 provided with the second recess 70B will be referred to as the second inner shroud 22B. When the first inner shroud 22A and the second inner shroud 22B are referred to collectively or when there is no need to distinguish between the first inner shroud 22A and the second inner shroud 22B, they will be simply referred to as the inner shroud 22.

[0036] In the following description, the stator vane 20 including the first inner shroud 22A will be referred to as the first stator vane 20A, and the stator vane 20 including the second inner shroud 22B will be referred to as the second stator vane 20B. When the first stator vane 20A and the second stator vane 20B are referred to collectively or when there is no need to distinguish between the first stator vane 20A and the second stator vane 20B, they will simply be referred to as the stator vane 20.

[0037] In the stator vane segment 11 according to some embodiments, the plurality of first stator vanes 20A and the plurality of second stator vanes 20B are arranged alternately in the circumferential direction Dc.

[0038] In the stator vane segment 11 according to some embodiments, the dimension of the recess 70 in the circumferential direction Dc is larger than the dimension in the axial direction Da. This makes it easier to ensure an area where the spring member 60 presses the inner shroud body 23 in an area where the recess 70 is not provided, as will be described later, and also makes it easier to ensure the size of the recess 70.

[0039] In the vane segments 11 according to some embodiments, as described above, the position in the axial direction Da of the recessed portion 70 in the inner shroud body 23 differs between the first vane 20A and the second vane 20B. The portion where the spring member 60 comes into contact with the inner shroud body 23 in order to apply a biasing force to the inner shroud body 23 by the spring member 60 may be the radially inner surface 23a of the inner shroud body 23 other than the recessed portion 70. Therefore, for example, if the recessed portions 70 are arranged in an area on one side in the axial direction Da in all the stator vanes 20, it is desirable to arrange the spring member 60 so as to avoid that area, which reduces the degree of freedom in setting the arrangement area of ​​the spring member 60. According to the vane segment 11 of some embodiments, the position in the axial direction Da of the recess 70 in the inner shroud body 23 differs between the first stator vane 20A and the second stator vane 20B. This makes it easier to arrange the spring members 60, for example, by arranging the spring member 60 that biases the first stator vane 20A configured to avoid the recess 70 of the second stator vane 20B, and the spring member 60 that biases the second stator vane 20B configured to avoid the recess 70 of the first stator vane 20A, at different positions in the axial direction Da, as will be described later.

[0040] The recessed portion 70 may be provided not only at a position closer to the upstream side or downstream side in the axial direction Da, but also at a position intermediate between the upstream side and the downstream side in the axial direction Da. In some embodiments, the inner shroud 22 may include, for example, an inner shroud 22 (first inner shroud) having a recess 70 on the upstream side in the axial direction Da as shown by the solid line in FIG. 11A, an inner shroud 22 (third inner shroud) having a recess 70 at a position midway between the upstream side and the downstream side in the axial direction Da as shown by the two-dot chain line in FIG. 11A, and an inner shroud 22 (second inner shroud) having a recess 70 on the downstream side in the axial direction Da as shown by the two-dot chain line in FIG. 11A. The stator blades 20 may be arranged in the stator blade segment 11 so that the circumferential direction Dc inner shrouds 22 are arranged in the order of, for example, the first inner shroud, the third inner shroud, and the second inner shroud.

[0041] In this case, the spring members 60 may be configured to urge the inner shroud body 23 radially outward in a region in the axial direction Da where no recesses 70 are provided. For example, although not shown, in the stator vane segment 11 according to some embodiments, a spring member 60 (third spring member) whose arrangement position in the axial direction Da is different from that of a first spring member 60A and a second spring member 60B described below may be provided, and the first spring member 60A may urge the inner shroud body 23 of the first inner shroud, the second spring member 60B may urge the inner shroud body 23 of the second inner shroud, and the third spring member may urge the inner shroud body 23 of the third inner shroud.

[0042] Alternatively, as shown in FIG. 11B, a recess 70 may be provided only at a midpoint between the upstream side and the downstream side in the axial direction Da. In this case, the spring member 60 is preferably configured to bias the inner shroud body 23 radially outward in at least one of the upstream and downstream regions where no recess 70 is provided in the axial direction Da, and preferably in both the upstream and downstream regions.

[0043] The recessed portion 70 may be provided at a position closer to one side or the other side in the circumferential direction Dc, for example, as shown in FIG. In some embodiments, the inner shroud 22 may include an inner shroud 22 (first inner shroud) having a recess 70 on one side in the circumferential direction Dc, as shown by the solid line in Figure 12, and an inner shroud 22 (second inner shroud) having a recess 70 on the other side in the circumferential direction Dc, as shown by the dotted line in Figure 12. The stator blades 20 may be arranged in the stator blade segment 11 so that the circumferential direction Dc inner shrouds 22 are arranged in the order of, for example, the first inner shroud and the second inner shroud.

[0044] In this case, the spring members 60 may be configured to urge the inner shroud body 23 radially outward in an area in the circumferential direction Dc where no recesses 70 are provided. For example, although not shown, in the stator vane segment 11 according to some embodiments, the inner shroud body 23 of the first inner shroud may be urged by a first spring member 60A described later, and the inner shroud body 23 of the second inner shroud may be urged by a second spring member 60B described later.

[0045] In this way, in the vane segment 11 according to some embodiments, the positions of the recesses 70 in the inner shroud body 23 may differ between the vanes 20 adjacent to each other in the circumferential direction Dc. By making the positions of the recesses 70 in the inner shroud body 23 different between adjacent stator vanes 20 in the circumferential direction Dc, the degree of freedom in the placement position of the spring member 60, which is configured to abut while avoiding the recesses 70, is increased, making it easier to place the spring member 60.

[0046] (Details of the spring member 60) As shown in Figures 9A, 9B, 10A, and 10B, in some embodiments of the stator vane segment 11, the spring member 60 includes a first spring member 60A that urges the inner shroud 22 (first inner shroud 22A) of each of the multiple first stator vanes 20A radially outward, and a second spring member 60B that urges the inner shroud 22 (second inner shroud 22B) of each of the multiple second stator vanes 20B radially outward. In some embodiments of the vane segment 11, the first spring member 60A is arranged in the axially upstream region of the spring member accommodating portion 49, and the second spring member 60B is arranged in the axially downstream region of the spring member accommodating portion 49.

[0047] In the stator vane segment 11 according to some embodiments, by separately providing a first spring member 60A that urges the first inner shroud 22A of each of the multiple first stator vanes 20A radially outward, and a second spring member 60B that urges the second inner shroud 22B of each of the multiple second stator vanes 20B radially outward, the first spring member 60A and the second spring member 60B can be made to have a relatively simple structure.

[0048] As shown in Figures 9A and 10A, the outer protrusion 61 of the first spring member 60A presses radially outward an area axially downstream of the first recess 70A on the radially inner surface 23a of the inner shroud body 23 of the first inner shroud 22A, of the first inner shroud 22A and the second inner shroud 22B arranged alternately in the circumferential direction Dc. As shown in Figures 9B and 10B, the outer protrusion 61 of the second spring member 60B presses radially outward an area on the radially inner surface 23a of the inner shroud body 23 of the second inner shroud 22B, which is one of the first inner shroud 22A and the second inner shroud 22B arranged alternately in the circumferential direction Dc, that is axially upstream of the second recess 70B.

[0049] In this way, in the stator vane segment 11 according to some embodiments, the spring member 60 abuts against the inner shroud body 23 at a position where the recess 70 is not provided, and urges the inner shroud 22 radially outward. This ensures a relatively large contact area between the spring member 60 and the inner shroud 22, thereby reducing the surface pressure at the contact portion between the spring member 60 and the inner shroud 22 and reducing wear at the contact portion.

[0050] In the vane segment 11 according to some embodiments, as described above, each of the multiple first vanes 20A and each of the multiple second vanes 20B are arranged alternately in the circumferential direction Dc, so that the arrangement of the first vanes 20A and the second vanes 20B is regular, and the first spring member 60A and the second spring member 60B can have a relatively simple structure.

[0051] In the stator vane segment 11 according to some embodiments, the first spring member 60A and the second spring member 60B are arranged at different positions in the axial direction Da, as described above. As a result, if the first spring member 60A and the second spring member 60B are each members that extend in the circumferential direction Dc as described above, the arrangement of the first spring member 60A and the second spring member 60B becomes rational.

[0052] (Further weight reduction of the inner shroud 22) For example, as shown in FIG. 13 , in the stator vane segment 11 according to some embodiments, a first lightening portion 76 may be provided radially outwardly recessed and surrounded by the inner shroud main body 23 on at least one side and the other side in the circumferential direction Dc, on the radially inner side of the inner shroud main body 23, on the axially upstream side of the upstream leg 24 or on the axially downstream side of the downstream leg 26. Of the first lightening portions 76, the first lightening portion 76 provided axially upstream of the upstream leg portion 24 is also referred to as the upstream first lightening portion 76A, and the first lightening portion 76 provided axially downstream of the downstream leg portion 26 is also referred to as the downstream first lightening portion 76B. This further reduces the weight of the inner shroud 22 and further increases the natural frequency of the stator vanes 20, making it possible to make the stator vanes 20 less likely to resonate during operation of the compressor 1. This further reduces the vibration of the stator vanes 20, making it even more unlikely that problems caused by the vibration of the stator vanes 20 will occur.

[0053] For example, as shown in FIG. 13, in some embodiments, the vane segment 11 may have at least one of a second cutout portion 77 in the upstream lip portion 25, which is surrounded by the upstream lip portion 25 on at least one side and the other side in the circumferential direction Dc, or a third cutout portion 78 in the downstream lip portion 27, which is surrounded by the downstream lip portion 27 on at least one side and the other side in the circumferential direction. This further reduces the weight of the inner shroud 22 and further increases the natural frequency of the stator vanes 20, making it possible to make the stator vanes 20 less likely to resonate during operation of the compressor 1. This further reduces the vibration of the stator vanes 20, making it even more unlikely that problems caused by the vibration of the stator vanes 20 will occur.

[0054] 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.

[0055] The contents described in each of the above embodiments can be understood, for example, as follows. (1) A stator vane segment 11 of a compressor 1 according to at least one embodiment of the present disclosure includes a plurality of stator vanes 20 arranged in the circumferential direction Dc, holders (connecting holders 40) attached to inner shrouds 22 of the plurality of stator vanes 20, and spring members 60 arranged between each of the inner shrouds 22 and the holder (connecting holder 40), extending in the circumferential direction Dc, and applying a biasing force to separate each of the inner shrouds 22 and the holder (connecting holder 40) in the radial direction Dr. Each of the plurality of stator vanes 20 has a recessed portion 70, which is surrounded by the inner shroud main body 23 on the radially inner side of the inner shroud main body 23 of the inner shroud 22 and recessed radially outward. The spring member 60 abuts against the inner shroud main body 23 at a position where the recessed portion 70 is not provided, and biases the inner shroud 22 radially outward.

[0056] According to the configuration (1) above, by providing the recessed portion 70 in the inner shroud body 23, the weight of the inner shroud 22 is reduced and the natural frequency of the stator vanes 20 is increased, making it possible to make the stator vanes 20 less likely to resonate during operation of the compressor 1. This reduces the vibration of the stator vanes 20, making it less likely that problems caused by the vibration of the stator vanes 20 will occur. Furthermore, according to the configuration (1) above, the recess 70 is surrounded by the inner shroud main body 23 on the entire periphery radially inside of the inner shroud main body 23, and therefore the recess 70 is not exposed to the side surface 22s of the inner shroud 22. As a result, the contact state between the side surfaces 22s of the inner shrouds 22 adjacent to each other in the circumferential direction Dc becomes the same as the contact state between the side surfaces of conventional inner shrouds, and the possibility of an unintended malfunction occurring is extremely low. According to the above configuration (1), the spring member 60 abuts at a position where there is no recess 70 and urges the inner shroud 22 radially outward. This ensures a relatively large contact area between the spring member 60 and the inner shroud 22, thereby reducing the surface pressure at the contact portion between the spring member 60 and the inner shroud 22 and reducing wear at the contact portion.

[0057] (2) In some embodiments, in the configuration of (1) above, the inner shroud 22 may have two protruding portions (the upstream leg portion 24 and the downstream leg portion 26) that protrude radially inward from the radially inner side of the inner shroud body 23 and are provided at a distance from each other on the upstream side and the downstream side in the axial direction Da. The recessed portion 70 may be located between the two protruding portions (the upstream leg portion 24 and the downstream leg portion 26).

[0058] According to the configuration (2) above, the area of ​​the region between the two protrusions (upstream leg 24, downstream leg 26) in the inner shroud body 23 is relatively large, making it easy to provide the recess 70, making it easy to ensure the amount of thinning caused by the recess 70, and also making the restriction on the position of the recess 70 in that region relatively loose.

[0059] (3) In some embodiments, in the configuration of (1) or (2) above, the position of the recess 70 in the inner shroud body 23 may be different between the first stator vane 20A and the second stator vane 20B circumferentially adjacent to the first stator vane 20A.

[0060] According to the configuration (3) above, by making the position of the recessed portion 70 in the inner shroud body 23 different between the first stator vane 20A and the second stator vane 20B, the degree of freedom in the positioning of the spring member 60 configured to abut against the recessed portion 70 is increased, making it easier to position the spring member 60.

[0061] (4) In some embodiments, in the configuration of (3) above, the position of the recess 70 in the axial direction Da of the inner shroud body 23 may be different between the first stator vane 20A and the second stator vane 20B.

[0062] According to the configuration (4) above, for example, the spring member 60 (first spring member 60A) that biases the first stator vane 20A configured to avoid the recess 70 (second recess 70B) of the second stator vane 20B, and the spring member 60 (second spring member 60B) that biases the second stator vane 20B configured to avoid the recess (first recess 70A) of the first stator vane 20A can be arranged at different positions in the axial direction Da, making it easier to arrange the spring member 60.

[0063] (5) In some embodiments, in the configuration of (3) or (4) above, the plurality of stator vanes 20 may include a plurality of first stator vanes 20A and a plurality of second stator vanes 20B. The spring member 60 may include a first spring member 60A that biases the inner shrouds 22 (first inner shrouds 22A) of each of the plurality of first stator vanes 20A radially outward, and a second spring member 60B that biases the inner shrouds (second inner shrouds 22B) of each of the plurality of second stator vanes 20B radially outward.

[0064] According to the above configuration (5), the first spring member 60A and the second spring member 60B can have a relatively simple structure.

[0065] (6) In some embodiments, in the configuration of (5) above, the first stator vanes 20A and the second stator vanes 20B may be arranged alternately in the circumferential direction Dc.

[0066] According to the configuration (6) above, the first stator vanes 20A and the second stator vanes 20B are arranged regularly, so that the first spring members 60A and the second spring members 60B can have a relatively simple structure.

[0067] (7) In some embodiments, in the configuration of (5) or (6) above, the first spring member 60A and the second spring member 60B may be disposed at different positions in the axial direction Da.

[0068] According to the above configuration (7), when the first spring member 60A and the second spring member 60B are members that extend in the circumferential direction Dc, the arrangement of the first spring member 60A and the second spring member 60B becomes rational.

[0069] (8) In some embodiments, in any of the configurations (1) to (7) above, the inner shroud 22 may have two protrusions (upstream leg 24, downstream leg 26) that are provided spaced apart on the upstream and downstream sides in the axial direction and that protrude radially inward from the radially inner side of the inner shroud main body 23. A first lightening hole 76 that is surrounded by the inner shroud main body 23 on at least one side and the other side in the circumferential direction Dc and recessed radially outward may be provided on the radially inner side of the inner shroud main body 23, axially upstream of the axially upstream protrusion (upstream leg 24) or axially downstream of the axially downstream protrusion (downstream leg 26).

[0070] According to the configuration (8) above, the weight of the inner shroud 22 can be further reduced and the natural frequency of the stator vane 20 can be further increased, making it more difficult for the stator vane to resonate during operation of the compressor 1. This can further reduce the vibration of the stator vane 20, making it even more difficult for problems caused by the vibration of the stator vane 20 to occur.

[0071] (9) In some embodiments, in any of the configurations (1) to (8) above, the inner shroud 22 may have two protrusions (upstream leg 24, downstream leg 26) that protrude radially inward from the radially inner side of the inner shroud body 23 and are spaced apart on the upstream and downstream sides in the axial direction, respectively; an upstream claw portion (upstream lip portion 25) that protrudes axially upstream from the tip of the axially upstream protrusion (upstream leg 24) and engages with the holder (connecting holder 40); and a downstream claw portion (downstream lip portion 27) that protrudes axially downstream from the tip of the axially downstream protrusion (downstream leg 26) and engages with the holder (connecting holder 40). It is preferable to have at least one of a second cutout portion 77 in the upstream claw portion (upstream lip portion 25) surrounded by the upstream claw portion (upstream lip portion 25) on at least one side and the other side in the circumferential direction Dc, or a third cutout portion 78 in the downstream claw portion (downstream lip portion 27) surrounded by the downstream claw portion (downstream lip portion 27) on at least one side and the other side in the circumferential direction Dc.

[0072] According to the configuration (9) above, the weight of the inner shroud 22 can be further reduced and the natural frequency of the stator vane 20 can be further increased, making it more difficult for the stator vane 20 to resonate during operation of the compressor 1. This can further reduce the vibration of the stator vane 20, making it even more difficult for problems caused by the vibration of the stator vane 20 to occur.

[0073] (10) The compressor 1 according to at least one embodiment of the present disclosure includes a stator blade ring (stator blade stage 10) in which a plurality of stator blade segments 11 of any one of (1) to (9) above are arranged in the circumferential direction Dc.

[0074] According to the configuration (10) above, it is possible to reduce the vibration of the stator vanes 20 in the compressor 1, and to make it difficult for problems to occur due to the vibration of the stator vanes 20. This makes it possible to improve the reliability of the compressor 1. [Explanation of symbols]

[0075] 1 Compressor 10 Stator blade ring (Stator blade stage) 11 Stator vane segment 20 Stator blade 20A No. 1 stator vane 20B 2nd stator blade 22 Inner shroud 22A No. 1 inner shroud 22B No. 2 inner shroud 23 Inner shroud body 24 Upstream leg 25 Upstream lip 26 Downstream leg 27 Downstream lip 40 Connecting holder 60 Spring member 60A First spring member 60B Second spring member 70 recess 70A First recess 70B Second recess 76 First hollowed-out section 77 Second hollowed-out section 78 Third hollowed-out section

Claims

1. A compressor stator vane segment, comprising: a plurality of stator vanes arranged in a circumferential direction; a holder attached to inner shrouds of the plurality of stator vanes; a spring member disposed between each of the inner shrouds and the holder, extending in the circumferential direction, and applying a biasing force to separate each of the inner shrouds and the holder in the radial direction; Equipped with each of the plurality of stator vanes has a recessed portion that is recessed radially outward and whose entire periphery is surrounded by the inner shroud body, on the radially inner side of an inner shroud body of the inner shroud; the spring member abuts against the inner shroud body at a position where the recessed portion is not provided, and urges the inner shroud outward in the radial direction. Compressor stator vane segment.

2. the inner shroud has two protrusions that protrude from the radially inner side of the inner shroud body toward the radially inner side, the protrusions being provided on an upstream side and a downstream side in the axial direction and spaced apart from each other, The recess is located between the two protrusions. The compressor vane segment of claim 1 .

3. a position of the recessed portion in the inner shroud body differs between a first stator vane and a second stator vane adjacent to the first stator vane in the circumferential direction; The compressor vane segment according to claim 1 or 2.

4. an axial position of the recessed portion in the inner shroud body differs between the first stator vane and the second stator vane; The compressor vane segment of claim 3 .

5. the plurality of stator vanes include a plurality of first stator vanes and a plurality of second stator vanes, The spring member is a first spring member that biases the inner shroud of each of the plurality of first stator vanes radially outward; a second spring member that biases the inner shroud of each of the plurality of second stator vanes radially outward; Including, The compressor vane segment of claim 3 .

6. the first stator vanes and the second stator vanes are alternately arranged in the circumferential direction. The compressor vane segment of claim 5 .

7. The first spring member and the second spring member are disposed at different positions in the axial direction. The compressor vane segment of claim 5 .

8. the inner shroud has two protrusions that protrude from the radially inner side of the inner shroud body toward the radially inner side, the protrusions being provided on an upstream side and a downstream side in the axial direction and spaced apart from each other, a first lightening portion that is recessed radially outward and surrounded by the inner shroud body on at least one side and the other side in the circumferential direction, the first lightening portion being located on the radially inner side of the inner shroud body on the axially upstream side of the axially upstream protruding portion or on the axially downstream side of the axially downstream protruding portion; The compressor vane segment according to claim 1 or 2.

9. The inner shroud is two protrusions provided on an upstream side and a downstream side in the axial direction and spaced apart from each other, the protrusions protruding from the radially inner side of the inner shroud body toward the radially inner side; an upstream claw portion that protrudes in the axial direction upstream from a tip of the protruding portion on the axial upstream side and engages with the holder; a downstream claw portion that protrudes in the axial downstream direction from a tip of the protruding portion on the axial downstream side and engages with the holder; and The upstream claw portion has at least one of a second cutout portion surrounded by the upstream claw portion on at least one side and the other side in the circumferential direction, and a third cutout portion surrounded by the downstream claw portion on at least one side and the other side in the circumferential direction, The compressor vane segment according to claim 1 or 2.

10. 3. A stator blade ring in which a plurality of stator blade segments according to claim 1 or 2 are arranged in the circumferential direction. A compressor comprising:

Images