Strut structure and axial flow rotating machine having the same

Abstract

To provide a strut structure and an axial flow rotary machine that can obtain an appropriate damping effect on vibration.SOLUTION: A strut structure comprises: a hollow external cylinder strut extending in a direction intersecting with a rotation direction of a rotary part of an axial flow rotary machine, and connecting a fixed part supporting the rotary part, and a base part supporting the axial flow rotary machine; and a hollow internal cylinder strut provided inside the external cylinder strut.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a strut structure and an axial flow rotating machine having the same. [Background technology]

[0002] A known support structure for the shaft system of an axial flow rotating machine is one in which a bearing casing and an outer casing are connected and supported by struts. For example, Patent Document 1 discloses a strut structure installed between the shaft and casing of a turbofan. In such a structure, the strut typically has high rigidity, while the bearing and damper installed in the bearing have low rigidity. In this case, the damping effects of the bearing and damper provide damping against vibrations in the entire shaft system. However, if the strut has low rigidity, the shaft and bearing casing move rigidly, creating a vibration mode in which the strut deforms, resulting in a problem of vibration not being damped. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-112298 Summary of the Invention [Problem to be solved by the invention]

[0004] In view of the above-mentioned problems, the present disclosure aims to provide a strut structure that can provide an appropriate damping effect against vibrations, and an axial flow rotating machine having the strut structure. [Means for solving the problem]

[0005] In order to solve the above-mentioned problems and achieve the objectives, the strut structure of the present disclosure comprises a hollow outer cylindrical strut extending in a direction intersecting the rotational direction of the rotating part of the axial flow rotary machine and connected to a fixed part that supports the rotating part and a base part that supports the axial flow rotary machine, and an inner cylindrical strut that is arranged inside the outer cylindrical strut and has a hollow interior.

[0006] In order to solve the above-mentioned problems and achieve the objectives, the strut structure of the present disclosure comprises: an external cylindrical strut having a hollow interior that extends in a direction intersecting the rotational direction of a rotating part of an axial flow rotary machine and is connected to a fixed part that supports the rotating part and a base part that supports the axial flow rotary machine; a diaphragm part that is provided at the end of the external cylindrical strut where it connects to the base or the fixed part and has a damping part inside it and is capable of expanding and contracting; and a disk structure that is provided inside the diaphragm part and connected to the end of the external cylindrical strut.

[0007] In order to solve the above-mentioned problems and achieve the objectives, the strut structure of the present disclosure comprises: an external cylindrical strut having a hollow interior that extends in a direction intersecting the rotational direction of a rotating part of an axial flow rotary machine and is connected to a fixed part that supports the rotating part and a base that supports the axial flow rotary machine; a diaphragm part that is expandable and contractible and is provided at the end of the external cylindrical strut where it connects to the base or the fixed part; a damping structure that has an internal damping part that is provided between the diaphragm part and the base or the fixed part; and a disk structure that is connected to the end of the external cylindrical strut.

[0008] In order to solve the above-mentioned problems and achieve the objectives, the axial flow rotating machine of the present disclosure comprises any of the strut structures described above, a fixed part supported by the strut structure, and a rotating part rotatably supported by the fixed part and rotating in a direction intersecting the axial direction of the strut structure. [Effects of the Invention]

[0009] According to the present disclosure, it is possible to provide a strut structure for an axial flow rotary machine that can obtain an appropriate damping effect against vibrations, and an axial flow rotary machine having the same. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of an axial flow rotary machine. [Figure 2] FIG. 2 is a cross-sectional view taken along line AA in FIG. [Figure 3] FIG. 3 is a schematic diagram showing an example of the configuration of a strut structure according to the first embodiment. [Figure 4A] FIG. 4A is a schematic diagram showing an example of the configuration of an outer cylindrical strut of a strut structure. [Figure 4B] FIG. 4B is a schematic diagram showing an example of the configuration of an outer cylindrical strut of the strut structure. [Figure 5] FIG. 5 is a schematic diagram showing an example of the configuration of a strut structure. [Figure 6] FIG. 6 is a partially enlarged view of FIG. [Figure 7] FIG. 7 is a schematic diagram showing a first configuration example of a strut structure according to the second embodiment. [Figure 8] FIG. 8 is an explanatory diagram illustrating the vibration damping effect of the strut structure according to the second embodiment. [Figure 9] FIG. 9 is a cross-sectional view taken along line BB in FIG. [Figure 10] FIG. 10 is a schematic diagram showing a second configuration example of the strut structure according to the second embodiment. [Figure 11] FIG. 11 is a cross-sectional view taken along line CC in FIG. [Figure 12] FIG. 12 is a schematic diagram showing an example of the configuration of a strut structure according to the third embodiment. [Figure 13] FIG. 13 is a schematic diagram showing an example of the configuration of a strut structure according to the fourth embodiment. [Figure 14] FIG. 14 is a schematic diagram showing an example of the configuration of a strut structure according to the fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. However, the present disclosure is not limited to the embodiments described below.

[0012] (Strut structure for axial flow rotating machinery) First, an axial flow rotating machine to which a strut structure according to the present disclosure can be applied will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic diagram showing the configuration of the axial flow rotating machine. FIG. 2 is a cross-sectional view taken along line AA in FIG. 1. The axial flow rotating machine 100 may be a motor fan in which a fan is driven by a motor, a turbofan jet, a turbojet, a turboprop, an industrial gas turbine, or the like. As shown in FIGS. 1 and 2, the axial flow rotating machine 100 includes a strut structure 110, a bearing casing 120, bearings 130, a shaft 140, rotor blades 150, and an outer casing 160. In the axial flow rotating machine 100, the bearing casing 120 forms the stationary part of the rotating machine, and the shaft 140 and rotor blades 150 form the rotating part of the rotating machine. The outer casing 160 forms the base of the rotating machine.

[0013] The strut structure 110 is a structural member that is connected to and supports the bearing casing 120 and the outer casing 160. In other words, the strut structure 110 connects the bearing casing 120, which has a rotating structure inside, to the outer casing 160, which serves as the base. The bearing casing 120 is a structural member that supports the bearing 130 and the shaft 140 supported by the bearing 130 inside. The bearing 130 is provided on the outer periphery of the shaft 140 and supports the shaft 140 rotatably relative to the bearing casing 120. The shaft 140 is a member that has a non-driven member such as a fan connected to one end and is rotated by a driving source such as a motor or turbine. The rotor blades 150 are connected to the shaft 140 via a disk or the like and rotate as the shaft 140 rotates, compressing air and generating thrust. The outer casing 160 is a structural member that is connected to and supported by the strut structure 110, covers the outer periphery of the non-driven member, and forms a flow path for compressed air.

[0014] (First embodiment) Next, a strut structure according to a first embodiment will be described with reference to Fig. 3 to Fig. 6. Fig. 3 is a schematic diagram showing an example of the configuration of a strut structure according to the first embodiment. Fig. 4A is a schematic diagram showing an example of the configuration of an outer cylindrical strut of the strut structure. Fig. 4B is a schematic diagram showing an example of the configuration of an outer cylindrical strut of the strut structure. Fig. 5 is a schematic diagram showing an example of the configuration of a strut structure. Fig. 6 is a partially enlarged view of Fig. 5.

[0015] As shown in FIG. 3, the strut structure 110 according to the first embodiment includes an outer cylindrical strut 111 and an inner cylindrical strut 112.

[0016] As shown in FIG. 4A, the outer cylindrical strut 111 (111a) is a cylindrical member with a cross section that forms a perfect circle. The outer cylindrical strut 111 is hollow. It may also be a cylindrical member with a cross section that forms an ellipse, as in the outer cylindrical strut 111b shown in FIG. 4B. One end of the outer cylindrical strut 111 is connected to the bearing casing 120, and the other end is connected to the outer peripheral casing 160. The outer cylindrical strut 111 supports the outer peripheral casing 160 relative to the bearing casing 120, and in turn supports the bearing casing 120 relative to the outer peripheral casing 160. In this embodiment, the outer cylindrical strut 111 connects the bearing casing 120 and the outer peripheral casing 160, but the object to which it is connected is not particularly limited as long as it is connected to a fixed part that supports a rotating part and a base part that supports the fixed part.

[0017] Like the outer cylindrical strut 111, the inner cylindrical strut 112 is a cylindrical, hollow structural member. The inner cylindrical strut 112 preferably has a similar shape to the outer cylindrical strut 111, and when the cross section of the outer cylindrical strut 111b is elliptical as shown in FIG. 4B, the inner cylindrical strut 112 is preferably elliptical. The outer diameter of the inner cylindrical strut 112 is smaller than the inner diameter of the outer cylindrical strut 111. Like the outer cylindrical strut 111, one end of the inner cylindrical strut 112 is connected to the bearing casing 120 and the other end is connected to the outer peripheral casing 160.

[0018] The strut structure 110 according to the first embodiment has an inner cylindrical strut 112 provided inside an outer cylindrical strut 111. The outer cylindrical strut 111 and the inner cylindrical strut 112 are fitted together by clearance fit.

[0019] When the strut structure 110 undergoes bending deformation, sliding contact occurs between the outer cylindrical struts 111 and the inner cylindrical struts 112. This sliding contact between the two causes a frictional force to act between the outer cylindrical struts 111 and the inner cylindrical struts 112 in the direction opposite to the vibration direction. This frictional force acts as a damping force against the vibration of the strut structure 110. This makes it possible to appropriately damp the vibration of the strut structure 110.

[0020] As in the strut structure 110c shown in Figures 5 and 6, at least one of the inner circumferential portion of the outer cylindrical strut 111c and the outer circumferential portion of the inner cylindrical strut 112c may have unevenness. In the example shown in Figures 5 and 6, the surface of the inner cylindrical strut 112c has an uneven shape. Note that the inner circumferential surface of the outer cylindrical strut 111c may also have an uneven shape, or both the inner circumferential portion of the outer cylindrical strut 111c and the outer circumferential portion of the inner cylindrical strut 112c may have an uneven shape.

[0021] By forming an uneven shape on the surface of the inner cylindrical struts 112c of the strut structure 110c, it is possible to increase the frictional force that occurs between the inner peripheral portion of the outer cylindrical struts 111c and the outer peripheral portion of the inner cylindrical struts 112c when the strut structure 110c is bent and deformed. Specifically, since the frictional force acts in the opposite direction to the vibration direction, the unevenness can increase the damping force against vibration. As a result, it is possible to appropriately damp the vibration of the strut structure 110c.

[0022] (Second embodiment) Next, a strut structure 110d according to a second embodiment will be described in detail with reference to Fig. 7. Fig. 7 is a schematic diagram showing a first configuration example of a strut structure according to the second embodiment.

[0023] 7, the strut structure 110 according to the second embodiment includes an outer cylindrical strut 111d, an inner cylindrical strut 112d, a damping portion 113, a cover portion 114, and a partition portion 115. The outer cylindrical strut 111d according to the second embodiment differs from the first embodiment in that it includes the damping portion 113, the cover portion 114, and the partition portion 115.

[0024] The inner cylindrical strut 112d according to the second embodiment has one end that is not connected to the bearing casing 120 and the other end that is connected to the outer casing 160. The inner cylindrical strut 112d is different from the inner cylindrical strut 112 according to the first embodiment in that one end is not fixed, i.e., in this embodiment, it is not connected to the bearing casing 120. Note that although the inner cylindrical strut 112d is connected to the outer casing 160, it may also be connected to the bearing casing 120 and not fixed to the outer casing 160. It is sufficient that the strut structure is provided with a structure on at least one side to be connected, and this is not limited to one end, as is the case with the embodiments described below.

[0025] The damping member 113 is a member provided between the outer cylindrical strut 111d and the inner cylindrical strut 112d to damp vibration. The damping member 113 can be made of a highly viscous fluid such as lubricating oil. One example of the damping member 113 is hydraulic oil used in oil dampers. The damping member 113 is not limited to a liquid, and may be made of an elastomer material such as rubber as long as it has a damping function.

[0026] The cover portion 114 covers the end of the inner cylindrical strut 112d that is exposed to the outer cylindrical strut 111d. By sealing the end of the inner cylindrical strut 112d with the cover portion 114, the damping portion 113 is not disposed inside.

[0027] The partition 115 is a member that separates the space inside the outer cylindrical strut 111d. The partition 115 is arranged on the side away from the end of the inner cylindrical strut 112d, which is provided inside the outer cylindrical strut 111d and has the cover portion 114. The partition 115 separates the area where the damping portion 113 of the outer cylindrical strut 111d is arranged from the area where the damping portion 113 is not arranged.

[0028] FIG. 8 is an explanatory diagram illustrating the vibration damping effect of a strut structure according to a second embodiment. FIG. 9 is a cross-sectional view taken along line BB in FIG. 8. When the strut structure 110d undergoes bending deformation as shown in FIGS. 8 and 9, the inner cylindrical strut 112d disposed inside the outer cylindrical strut 111d displaces in the same direction as the bending direction of the outer cylindrical strut 111d. In the strut structure 110d, the deformation of the outer cylindrical strut 111d causes the inner cylindrical strut 112d to displace, causing the damping section 113, which is a highly viscous fluid, to move in the direction indicated by the arrow in FIG. 9. As this occurs, the fluid moves through a narrow gap, creating a pressure difference in the fluid. This pressure difference increases with the fluid's speed, acting as a damping force. Furthermore, as the gap filled with the viscous fluid narrows, the fluid escapes to the left and right, generating a damping force due to the squeeze effect.

[0029] Furthermore, if the damping section 113 of the strut structure 110d is made of an elastomer material such as rubber, when a displacement difference, i.e., a relative velocity, occurs between the outer cylindrical strut 111d and the inner cylindrical strut 112d, the elastomer damping section 113 elastically deforms and receives an elastic force according to the displacement difference, i.e., the relative velocity, between the outer cylindrical strut 111d and the inner cylindrical strut 112d, which acts as a damping force against vibration. Even when the damping section 113 of the strut structure 110d is made of an elastomer, the damping force can still provide a vibration damping effect.

[0030] Furthermore, the strut structure 110d has a structure in which one end of the inner cylindrical strut 112d is open (free end) within the outer cylindrical strut 111d and is provided with a cover portion 114, thereby increasing the degree of freedom of displacement of one end of the inner cylindrical strut 112d and increasing the displacement difference between the outer cylindrical strut 111d and the inner cylindrical strut 112d, i.e., the relative velocity, thereby increasing the damping force.

[0031] Furthermore, by providing the partition 115 in the strut structure 110d, it is possible to reduce the volume of the damping section 113 provided between the outer cylindrical strut 111d and the inner cylindrical strut 112d. This makes it possible to reduce the weight of the strut structure 110d, providing properties suitable for use as a strut structure 110d in axial flow rotating machines for aircraft, where increased weight directly leads to a decrease in fuel efficiency.

[0032] The configuration of the strut structure 110 according to the second embodiment is not limited to the configuration shown in Fig. 7, and may be the configurations shown in Fig. 10 and Fig. 11. Fig. 10 is a schematic diagram showing a second configuration example of the strut structure according to the second embodiment. Fig. 11 is a cross-sectional view taken along line CC in Fig. 10.

[0033] 10, a strut structure 110e according to the second embodiment includes an outer cylindrical strut 111e, an inner cylindrical strut 112e, a damping portion 113e, a cover portion 114e, and an intermediate strut 116. The outer cylindrical strut 111e, the inner cylindrical strut 112e, the damping portion 113e, and the cover portion 114e are the same as those in the second embodiment, and therefore description thereof will be omitted.

[0034] The intermediate strut 116 is provided between the inner cylindrical strut 112e and the outer cylindrical strut 111e, and is formed outside the inner cylindrical strut 112e so as to cover the inner cylindrical strut 112e. In the second configuration example of the second embodiment, a damping portion 113e is provided between the inner peripheral portion of the intermediate strut 116 and the outer peripheral portion of the inner cylindrical strut 112e.

[0035] When the inner cylindrical strut 112e is displaced, the strut structure 110e receives a damping force from the damping section 113e in the direction of displacement of the inner cylindrical strut 112e, i.e., in the opposite direction to the direction of the relative velocity with respect to the outer cylindrical strut 111e, as shown in Figure 11. This provides a vibration damping effect. By providing the intermediate strut 116, the volume of the damping section 113e can be reduced, making the strut structure 110e even lighter.

[0036] (Third embodiment) Next, a strut structure 110f according to the third embodiment will be described in detail with reference to Fig. 12. Fig. 12 is a schematic diagram showing an example of the configuration of a strut structure according to the third embodiment.

[0037] 12, a strut structure 110f according to the third embodiment includes an outer cylindrical strut 111f, an inner cylindrical strut 112f, a damping portion 113f, a cover portion 114f, a partition portion 115f, and a diaphragm portion 117. The outer cylindrical strut 111f, the inner cylindrical strut 112f, the damping portion 113f, the cover portion 114f, and the partition portion 115f are similar to those of the strut structure 110d according to the second embodiment, and therefore a description thereof will be omitted.

[0038] The diaphragm portion 117 is provided at the end of the outer cylindrical strut 111f, which in this embodiment is the end on the outer cylindrical casing 160 side that serves as the base. The diaphragm portion 117 has a larger diameter than the outer cylindrical strut 111f, and its interior is connected to the outer cylindrical strut 111f. The internal space of the diaphragm portion 117 serves as the damping portion 113f. The diaphragm portion 117 is a member that can expand and contract, that is, a flexible member. The outer cylindrical strut 111f is connected to the outer cylindrical casing 160 via the diaphragm portion 117.

[0039] When vibration occurs, the diaphragm portion 117 of the strut structure 110f deforms, increasing the displacement of the outer cylindrical strut 111f. The inner cylindrical strut 112f is rigidly joined to the outer cylindrical casing 160 as a cantilever beam structure. As a result, as the difference in displacement between the two, that is, the relative speed between the two, increases when vibration occurs, the damping force received from the damping portion 113f also increases due to the relative speed between the two. As a result, the outer cylindrical strut 111f has a low rigidity but a large vibration damping effect.

[0040] The strut structure 110f can increase the difference in displacement between the outer cylindrical struts 111f and the inner cylindrical struts 112f when vibration occurs, i.e., the relative velocity between them, thereby enhancing the vibration damping effect, and therefore making it possible to appropriately damp the vibration of the strut structure 110f.

[0041] (Fourth embodiment) Next, a strut structure 110g according to a fourth embodiment will be described in detail with reference to Fig. 13. Fig. 13 is a schematic diagram showing an example of the configuration of a strut structure according to the fourth embodiment.

[0042] 13, the strut structure 110g includes an outer cylindrical strut 111g, a damping portion 113g, a diaphragm portion 117g, a disk structure 118, and an O-ring 118o. The outer cylindrical strut 111g, the damping portion 113g, and the diaphragm portion 117g are similar to those of the strut structure 110f of the third embodiment, and therefore description thereof will be omitted. The strut structure 110g of the fourth embodiment does not include an inner cylindrical strut 112, and the outer cylindrical strut 111g is connected to the outer peripheral casing 160 via the diaphragm portion 117g.

[0043] The disk structure 118 is a disk-shaped member provided inside the diaphragm portion 117g and connected to the end of the outer cylindrical strut 111g. The O-ring 118o is provided between the outer periphery of the disk structure 118 and the inner periphery of the diaphragm portion 117g. The O-ring 118o supports the disk structure 118 so that it can be displaced inside the diaphragm portion 117g. The damping portion 113g is filled in the area surrounded by the disk structure 118, the diaphragm portion 117g, and the O-ring 118o.

[0044] As shown in Figure 13, the disk structure 118 is connected to the end of the outer cylindrical strut 111g. When the outer cylindrical strut 111g is displaced due to vibration, the disk structure 118 of the strut structure 110g is displaced in accordance with the displacement of the outer cylindrical strut 111g. Because the inside of the diaphragm portion 117 is filled with a damping portion 113g, a damping force acts in the opposite direction of the relative velocity between the disk structure 118 and the diaphragm portion 117.

[0045] The strut structure 110g includes a diaphragm portion 117 and a disk structure 118, which allows it to flexibly support the outer cylindrical strut 111g while providing a vibration damping effect. Furthermore, by increasing the diameter of the diaphragm portion 117, the displacement of the disk structure 118, i.e., its relative speed with respect to the diaphragm portion 117, increases, thereby increasing the damping force acting in accordance with the displacement of the disk structure 118, i.e., its relative speed with respect to the diaphragm portion 117. This makes it possible to appropriately damp vibrations of the strut structure 110g. Furthermore, the inclusion of the damping portion 113g further increases the damping force.

[0046] (Fifth embodiment) Next, a strut structure 110h according to a fifth embodiment will be described in detail with reference to Fig. 14. Fig. 14 is a schematic diagram showing an example of the configuration of a strut structure according to the fifth embodiment.

[0047] 14, a strut structure 110h according to the fifth embodiment includes an outer cylindrical strut 111h, a damping portion 113h, a diaphragm portion 117h, a disk structure 118h, and a damping structure 119. The outer cylindrical strut 111h, the damping portion 113h, the diaphragm portion 117h, and the disk structure 118h are the same as those in the fourth embodiment, and therefore description thereof will be omitted. Note that the fifth embodiment differs from the fourth embodiment in that the diaphragm portion 117h does not include the damping portion 113h, and a damping structure 119 is provided between the diaphragm portion 117h and an object to which the strut structure 110h is connected, which in this embodiment is the outer casing 160.

[0048] The damping structure 119 is provided between the diaphragm portion 117h and the outer casing 160. The damping structure 119 is a structural member having therein a damping portion 113h, a disk structure 118h, and an O-ring 118o. The disk structure 118h is provided and connected to the end of the outer cylindrical strut 111h. An O-ring 118o is provided in an opening of the damping structure 119 where the outer cylindrical strut 111h is disposed. This prevents the damping portion 113h from leaking out of the damping structure 119. In addition, an O-ring 118o is provided between the inner periphery of the damping structure 119 and the outer periphery of the disk structure 118. This makes it possible to support the disk structure 118h provided inside the damping structure 119 so that it can be displaced inside the damping structure 119.

[0049] The strut structure 110h has a diaphragm portion 117h that flexibly supports the outer cylindrical strut 111h, and a damping structure 119 that generates a damping effect. This allows the characteristics of the diaphragm portion 117h, which controls rigidity, and the damping structure 119, which controls damping, to be designed separately. Furthermore, by providing the damping portion 113h inside the damping structure 119, the rigidity of the structure surrounding the damping portion 113h is increased, thereby preventing a reduction in damping effect due to expansion and contraction deformation of the diaphragm portion 117h. Furthermore, the inner diameter of the damping structure 119 can be increased, allowing a highly viscous fluid to detour, increasing resistance and increasing damping force. This allows the vibration of the strut structure 110h to be appropriately damped.

[0050] Here, the strut structure 110 is preferably provided in an axial flow rotating machine. The axial flow rotating machine is preferably a motor fan. The motor fan may be, for example, a peripheral drive motor fan. A peripheral drive motor has a structure in which a drive coil is arranged inward on the outer periphery and a rotating coil is arranged on the outer periphery of a rotor facing the drive coil. A fluctuating magnetic field is generated in the drive coil on the outer periphery, and a current is passed through the rotating coil by electromagnetic induction, generating a rotational force through interaction with the magnetic field. Because the rotational force is applied from the outer periphery, a large torque can be obtained with a small rotational force. Motor fans generate torque vibrations or torque ripples due to the magnetic pole passing frequency of the motor. Such torque vibrations cause undesirable vibrations in the structural member to which the motor is attached. Therefore, using the strut structure 110 according to the present disclosure as a structural member of the motor fan to which the motor is attached enables appropriate vibration damping.

[0051] (Composition and Effects) The strut structure 110 of the present disclosure comprises a hollow outer-tube strut 111 extending in a direction intersecting the rotational direction of the rotating part of the axial flow rotary machine and connected to a fixed part that supports the rotating part and a base part that supports the axial flow rotary machine, and an inner-tube strut 112 that is arranged inside the outer-tube strut 111 and has a hollow interior.

[0052] With this configuration, when vibration is applied to the strut structure 110, the outer periphery of the inner cylindrical strut 112 provided inside the outer cylindrical strut 111 comes into contact with the inner periphery of the outer cylindrical strut 111, generating a frictional force that acts as a damping force against the vibration. Therefore, it is possible to provide a strut structure 110 that can obtain an appropriate damping effect against vibration.

[0053] The outer cylindrical strut 111 and the inner cylindrical strut 112 of the strut structure 110 according to the present disclosure are fitted together by clearance fit.

[0054] This configuration increases the frequency with which the outer cylindrical struts 111 and the inner cylindrical struts 112 come into contact when vibration is applied to the strut structure 110. In other words, it increases the frequency with which a damping force against vibration acts. As a result, it is possible to provide a strut structure 110 that provides an appropriate damping effect against vibration.

[0055] The strut structure 110 according to the present disclosure has irregularities on at least one of the inner periphery of the outer cylindrical strut 111 and the outer periphery of the inner cylindrical strut 112 .

[0056] With this configuration, when vibration is applied to the strut structure 110, the frictional force caused by contact between the outer periphery of the outer cylindrical strut 111 and the inner periphery of the inner cylindrical strut 112 can be increased. Because the frictional force acts in the opposite direction to the sliding direction, it acts as a damping force against the vibration. In other words, with this configuration, the damping force against the vibration can be increased. As a result, it is possible to provide a strut structure 110 that can obtain an appropriate damping effect against vibration.

[0057] The strut structure 110 according to the present disclosure further includes a damping portion 113 between the inner periphery of the outer cylindrical strut 111 and the outer periphery of the inner cylindrical strut 112, which damps vibrations.

[0058] With this configuration, when vibration is applied to the strut structure 110, a damping force acts in the opposite direction to the vibration direction by the damping section 113 provided between the outer periphery of the outer cylindrical strut 111 and the inner periphery of the inner cylindrical strut 112. This makes it possible to provide a strut structure 110 that provides an appropriate damping effect against vibration.

[0059] The inner tube strut 112d of the strut structures 110d, 110e according to the present disclosure has a length shorter than the total length of the outer tube strut 111d, is provided at an end of the inner tube strut 112d that is not connected to other parts of the inner tube strut 112d, has a cover portion 114 that covers the end of the inner tube strut 112d, is positioned at the end of the outer tube strut 111d on the side where the inner tube strut 112d has the cover portion 114, and has a partition portion 115 that separates the area where the damping portion 113d of the outer tube strut 111d is located from the area where the damping portion 113d is not located.

[0060] This configuration allows the length of the inner cylindrical strut 112d to be shortened and the volume of the damping section 113d to be reduced, thereby reducing the weight of the strut structures 110d, 110e. Furthermore, an appropriate damping effect can be obtained when vibration is applied to the strut structures 110d, 110e. Therefore, it is possible to provide strut structures 110d, 110e that provide an appropriate damping effect against vibration.

[0061] An outer cylindrical strut 111f of a strut structure 110f according to the present disclosure has a diaphragm portion 117 that is provided at the end on the side where the damping portion 113f is arranged and is capable of expanding and contracting.

[0062] This configuration increases the difference in displacement between the outer cylindrical struts 111f and the inner cylindrical struts 112f when vibration occurs, i.e., the relative velocity between them, thereby improving the vibration damping effect, and thus providing a strut structure 110f that provides an appropriate vibration damping effect.

[0063] The strut structure 110g of the present disclosure comprises a hollow external cylindrical strut 111g that extends in a direction intersecting the rotational direction of the rotating part of the axial flow rotary machine and is connected to a fixed part that supports the rotating part and a base that supports the axial flow rotary machine; a diaphragm part 117g that is provided at the end where the external cylindrical strut 111g connects to the base and has a damping part 113g inside it and is capable of expanding and contracting; and a disk structure 118 that is provided inside the diaphragm part 117g and connected to the end of the external cylindrical strut 111g.

[0064] This configuration provides a vibration damping effect while flexibly supporting the outer cylindrical strut 111g. Furthermore, by increasing the diameter of the diaphragm portion 117g, the displacement of the disk structure 118, i.e., the relative speed with respect to the diaphragm portion 117g, increases, thereby increasing the damping force acting due to the displacement of the disk structure 118, i.e., the relative speed with respect to the diaphragm portion 117g. This makes it possible to provide a strut structure 110g that provides an appropriate vibration damping effect.

[0065] The strut structure 110h of the present disclosure comprises a hollow external cylindrical strut 111h that extends in a direction intersecting the rotational direction of the rotating part of the axial flow rotary machine and is connected to a fixed part that supports the rotating part and a base that supports the axial flow rotary machine, a diaphragm part 117h that is provided at the end where the external cylindrical strut 111h connects to the base and is capable of expanding and contracting, a damping structure 119 that is provided between the diaphragm part 117h and the base and has a damping part 113h inside, and a disk structure 118h that is connected to the end of the external cylindrical strut 111h.

[0066] This configuration increases the rigidity of the structure surrounding the damping portion 113h, thereby preventing a reduction in the damping effect due to the expansion and contraction deformation of the diaphragm portion 117h. Furthermore, the inner diameter of the damping structure 119 can be increased, forcing the fluid to take a longer route, increasing resistance and enhancing damping force. This makes it possible to provide a strut structure 110h that provides an appropriate damping effect against vibrations.

[0067] Although the embodiments of the present disclosure have been described above, the embodiments are not limited to the contents of these embodiments. Furthermore, the above-described components include those that can be easily imagined by a person skilled in the art, those that are substantially the same, and those that are within the so-called equivalent range. Furthermore, the above-described components can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications of the components can be made without departing from the spirit of the above-described embodiments. [Explanation of symbols]

[0068] 100 Axial Rotating Machine 110 Strut structure 111 Outer cylinder strut 112 Inner cylinder strut 113 Attenuation section 114 Cover part 115 Partition 116 Intermediate strut 117 Diaphragm part 118 Disk Structure 119 Damping Structure 120 Bearing casing 130 bearings 140 axes 150 Moving blade 160 outer casing

Claims

1. a hollow outer cylinder strut extending in a direction intersecting a rotation direction of a rotary portion of the axial flow rotary machine and connecting to a fixed portion supporting the rotary portion and a base portion supporting the axial flow rotary machine; an inner cylindrical strut provided inside the outer cylindrical strut and having a hollow interior, The inner cylindrical strut is fitted to the outer cylindrical strut by a clearance fit, At least one of the inner circumferential portion of the outer cylindrical strut and the outer circumferential portion of the inner cylindrical strut has irregularities. Strut structure.

2. The strut structure according to claim 1 , further comprising a damping portion for damping vibration between an inner peripheral portion of the outer cylindrical strut and an outer peripheral portion of the inner cylindrical strut.

3. the inner cylindrical strut has a length shorter than the overall length of the outer cylindrical strut; a cover portion provided at an end portion of the inner tube strut that is not connected to other portions and that covers the end portion of the inner tube strut; 3. A strut structure according to claim 2, wherein the inner cylindrical strut is arranged at the end of the outer cylindrical strut on the side having the cover portion, and the outer cylindrical strut has a partition portion separating an area where the damping portion is arranged from an area where the damping portion is not arranged.

4. a hollow outer cylinder strut extending in a direction intersecting a rotation direction of a rotary portion of the axial flow rotary machine and connecting to a fixed portion supporting the rotary portion and a base portion supporting the axial flow rotary machine; an inner cylindrical strut provided inside the outer cylindrical strut and having a hollow interior; a damping portion for damping vibration between an inner peripheral portion of the outer cylindrical strut and an outer peripheral portion of the inner cylindrical strut, the inner cylindrical strut has a length shorter than the overall length of the outer cylindrical strut; a cover portion provided at an end portion of the inner tube strut that is not connected to other portions and that covers the end portion of the inner tube strut; A strut structure in which the inner cylindrical strut is arranged at the end of the outer cylindrical strut on the side having the cover portion, and which has a partition portion that separates the area of ​​the outer cylindrical strut in which the damping portion is arranged from an area in which the damping portion is not arranged.

5. The outer cylindrical strut has a diaphragm portion that is provided at an end on the side where the damping portion is disposed and is expandable and contractible. The strut structure according to claim 3 or 4.

6. The strut structure according to any one of claims 1 to 5; a fixed portion supported by the strut structure; a rotating part rotatably supported on the fixed part and rotating in a direction intersecting the axial direction of the strut structure.

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