Rotary machine

Abstract

A rotary machine is provided with: a rotor; an annular seal body portion including an inner circumferential surface, which is a stationary wall surface facing the outer circumferential surface of the rotor, and a plurality of holes formed in the inner circumferential surface; a plurality of stationary fins provided on the inner peripheral surface at intervals in the axial direction of the rotor; and at least one first rotor fin portion provided on the outer circumferential surface of the rotor, each of the plurality of stationary fin portions extending in the circumferential direction of the rotor and protruding from the inner circumferential surface toward the outer circumferential surface of the rotor, and each of the at least one first rotor fin portion extending in the circumferential direction and protruding from the outer circumferential surface of the rotor toward the hole.

Description

Technical Field

[0001] This invention relates to a rotating machine.

[0002] This application claims priority based on Japanese Patent Application No. 2023-099099, filed with the Japan Patent Office on June 16, 2023, the contents of which are incorporated herein by reference. Background Technology

[0003] For example, in rotating machinery such as turbines, unstable vibrations, such as low-frequency vibrations, sometimes occur. When displacement occurs in the rotor of rotating machinery, the swirling flow (cyclone flow) flowing in the gap (sealing part) between the outer peripheral surface of the rotor and the stationary wall creates an uneven pressure distribution in this gap. Fluid forces in a direction orthogonal to the rotor's displacement direction act on the rotor, thereby promoting rotor oscillation. This fluid force is called the sealing excitation force, and the generation of the sealing excitation force reduces the rotor's axial stability (shaft system stability). Therefore, from the viewpoint of rotor axial stability, reducing the sealing excitation force is important.

[0004] As a sealing structure to reduce the sealing excitation force, there are damping seals such as pocket damper seals, hole seals or honeycomb seals (for example, see Patent Document 1). If a damping seal is provided, the sealing excitation force can be reduced by the swirling reduction effect generated by introducing fluid into the hole (recess) provided on the stationary wall side, and the vibration reduction effect (squeeze film effect) generated by the narrowing of the gap between the stationary wall and the rotor.

[0005] Previous technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2016-153654 Summary of the Invention

[0008] The technical problem to be solved by the invention

[0009] In the damping seal described in Patent Document 1, the contact area between the rotor and the stationary wall tends to increase during rotor displacement, leading to a greater risk of thermal bending of the rotor due to frictional heat between the rotor and the stationary wall (hereinafter sometimes referred to as "contact risk between the rotor and the stationary wall"). On the other hand, if the gap between the outer circumference of the rotor and the stationary wall is simply increased to reduce the contact risk, the aforementioned squeezing film effect weakens, and the reduction effect of the sealing excitation force weakens. Therefore, there is a challenge in simultaneously reducing the contact risk between the rotor and the stationary wall and achieving high axial stability of the rotor.

[0010] In view of the above, the object of at least one embodiment of the present invention is to provide a rotating machine that can reduce the risk of contact between the rotor and a stationary wall while achieving high axial stability of the rotor.

[0011] means for solving technical problems

[0012] To achieve the above objectives, at least one embodiment of the rotating machinery according to the present invention comprises:

[0013] Rotor;

[0014] The annular sealing body includes a stationary wall surface, i.e. an inner circumferential surface, facing the outer circumferential surface of the rotor, and a plurality of holes formed in the inner circumferential surface;

[0015] Multiple stationary fins are spaced apart along the axial direction of the rotor on the inner circumferential surface; and

[0016] At least one first rotor fin portion is disposed on the outer peripheral surface of the rotor.

[0017] Each of the plurality of stationary fin portions extends circumferentially along the rotor and protrudes from the inner circumferential surface toward the outer circumferential surface of the rotor.

[0018] Each of the at least one first rotor fin portion extends along the circumferential direction and protrudes from the outer circumferential surface of the rotor toward the hole.

[0019] Invention Effects

[0020] According to at least one embodiment of the present invention, a sealing system for rotating machinery and a rotating machinery having the system are provided, which can reduce the risk of contact between the outer peripheral surface of the rotor and the stationary wall surface, and achieve high axial stability of the rotor. Attached Figure Description

[0021] Figure 1 This is a schematic diagram showing an example of a cross section orthogonal to the axial direction of a rotating machine 2 according to one embodiment.

[0022] Figure 2 It means Figure 1 A schematic diagram of an example of a cross-section along the axial direction of the rotating machinery 2 shown.

[0023] Figure 3 It is used for explanation Figure 2 A schematic diagram of the swirling flow in the cross-section shown.

[0024] Figure 4 It is used for explanation Figure 3 A schematic diagram of the swirling flow in a portion of section AA.

[0025] Figure 5 It is for use Figures 1-4 The illustrated implementation methods and comparison methods 1 to 4 are graphs showing the relationship between leakage flow and effective attenuation of shaft vibration of rotor 4.

[0026] Figure 6 It is for use Figures 1-4 The diagram illustrates the relationship between the axial position and the swirl ratio in the gap g between the outer peripheral surface 4a of the rotor 4 and the inner peripheral surface 12a of the sealing body 12 in each of the described embodiments and comparison method 1.

[0027] Figure 7 This is a schematic diagram showing another example of a cross-section along the axial direction of a rotating machine 2 according to one embodiment.

[0028] Figure 8A This is a schematic cross-sectional view used to illustrate the effective cross-sectional area of ​​the leakage flow when the stationary fin section 18 is not radially inclined.

[0029] Figure 8B This is a schematic cross-sectional view illustrating the effective cross-sectional area of ​​the leakage flow when the stationary fin section 18 is tilted in a manner that it is tilted towards the upstream side in the axial direction as it is tilted towards the radially inward side.

[0030] Figure 8C It is used for explanation Figure 7 A schematic diagram of the swirling flow in the cross-section shown.

[0031] Figure 9 It is Figure 7 The graph shows a comparison between the leakage flow rate and the effective attenuation of the shaft vibration of rotor 4 in the illustrated embodiment and the comparison methods 1 to 4 described above.

[0032] Figure 10 This is a schematic diagram showing another example of a cross-section along the axial direction of a rotating machine 2 according to one embodiment. Detailed Implementation

[0033] Hereinafter, several embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc., of the constituent components described as embodiments or shown in the drawings are not intended to limit the scope of the invention, but are merely illustrative examples.

[0034] For example, expressions such as "in a certain direction", "along a certain direction", "parallel", "orthogonal", "center", "concentric" or "coaxial" indicate relative or absolute configuration. They not only strictly indicate this configuration, but also indicate the state of relative displacement by angle or distance with tolerance or to obtain the same degree of functionality.

[0035] For example, expressions such as "same," "equal," and "homogeneous" that indicate that things are in an equal state not only strictly indicate an equal state, but also indicate a state where there is a tolerance or a difference in the degree to which the same function can be obtained.

[0036] For example, descriptions of shapes such as quadrilaterals and cylinders not only refer to quadrilaterals and cylinders in a strict geometric sense, but also include shapes with concave and convex parts, chamfered parts, etc., within the range where the same effect can be obtained.

[0037] On the other hand, the expression "possessing," "having," "including," "containing," or "having" one of the constituent elements is not an exclusive expression that excludes the existence of other constituent elements.

[0038] Figure 1 This is a schematic diagram showing an example of a cross-section orthogonal to the axial direction of a rotating machine 2 according to one embodiment. The rotating machine 2 may be, for example, a turbine such as a steam turbine or a compressor.

[0039] like Figure 1 As shown, the rotating machinery 2 includes a rotor 4 and a housing 6 that houses the rotor 4. The housing 6 has a housing body 8 that houses the rotor 4 and a sealing device 10 (a sealing device for rotating machinery).

[0040] In this specification, unless otherwise specified, "axial" refers to the axial direction of rotor 4, "circumferential" refers to the circumferential direction of rotor 4, and "radial" refers to the radial direction of rotor 4. Furthermore, the upstream side of the axial direction refers to the upstream side of the axial flow of fluid in the gap g between rotor 4 and housing 6 (the gap between rotor 4 and the inner circumferential surface 12a of the sealing body 12 described later), i.e., the high-pressure side of the axial direction in gap g; the downstream side of the axial direction refers to the downstream side of the axial flow of fluid in gap g, i.e., the low-pressure side of the axial direction in gap g.

[0041] like Figure 1 As partially shown, the sealing device 10 includes a sealing body portion 12 and a plurality of stationary fin portions 18. In the illustrated exemplary embodiment, the sealing body portion 12 is formed in an annular shape (e.g., cylindrical) and is held on the inner surface 8a of the housing body 8. The sealing body portion 12 includes a stationary wall surface, i.e., an inner peripheral surface 12a, opposite to the outer peripheral surface 4a of the rotor 4, and an outer peripheral surface 12b fixed to the inner surface 8a of the housing body 8.

[0042] A plurality of holes 16 (recesses) are formed on the inner circumferential surface 12a of the sealing body portion 12. Figure 1 The cross-section shown includes a plurality of holes 16 formed on the inner peripheral surface 12a of the sealing body portion 12, which are arranged at intervals in the circumferential direction.

[0043] Figure 2It means Figure 1 A schematic diagram of an example of a cross-section along the axial direction of the rotating machinery 2 shown. Figure 2 In the cross-section shown, the plurality of holes 16 formed on the inner peripheral surface 12a of the sealing body portion 12 include a plurality of holes 16 arranged at intervals in the axial direction. Figure 2 In the illustrative embodiment shown, the shape of the cross-section orthogonal to the radial direction of each of the plurality of holes 16 formed on the inner peripheral surface 12a of the sealing body 12 can be circular. That is, in Figure 2 In the exemplary embodiment shown, each of the plurality of holes 16 formed on the inner peripheral surface 12a of the sealing body portion 12 can be a bottomed recess forming a cylindrical cavity.

[0044] For example, such as Figure 2 As shown, the sealing device 10 includes a plurality of stationary fin portions 18 arranged axially at intervals on the inner peripheral surface 12a of the sealing body portion 12. Each of the plurality of stationary fin portions 18 extends circumferentially and protrudes radially inward from the inner peripheral surface 12a of the sealing body portion 12 toward the outer peripheral surface 4a of the rotor 4. Each of the plurality of stationary fin portions 18 may be formed in an annular shape centered on the rotation axis of the rotor 4.

[0045] For example, such as Figure 2 As shown, each of the plurality of stationary fin portions 18 can be positioned between two axially adjacent holes 16 on the inner peripheral surface 12a of the sealing body portion 12. Figure 2 In the cross-section shown, the holes 16 and the stationary fin portion 18 are arranged alternately along the axial direction. For example... Figure 2 As shown, from the viewpoint of reducing the contact area with the rotor 4 when the rotor 4 is displaced, the end portion of each of the stationary fin portions 18 may have a pointed shape (a shape in which the thickness decreases as it moves toward the radially inward side). In this case, the end face 18t on the end side of each of the stationary fin portions 18 may include an inclined surface 18t1. From the viewpoint of suppressing the increase of leakage flow in the gap g, the inclined surface 18t1 is inclined in a manner that moves toward the upstream side of the axial direction as it moves toward the radially inward side.

[0046] For example, such as Figure 2 As shown, the rotating machinery 2 includes a plurality of rotor fin portions 20 (a plurality of first rotor fin portions) provided on the outer peripheral surface 4a of the rotor 4. Each of the plurality of rotor fin portions 20 extends circumferentially and protrudes from the outer peripheral surface 4a of the rotor 4 toward a corresponding hole 16. Figure 2 In the cross-section shown, each rotor fin portion 20 is formed opposite to the bottom surface 16 of each hole 16 at a position Pc at the center of the hole 16 in the axial direction. Furthermore, in Figure 2In the illustrated embodiment, each rotor fin portion 20 is positioned between two axially adjacent stationary fin portions 18 among a plurality of stationary fin portions 18. The axial thickness t of each rotor fin portion 20 is less than the axial dimension w of each hole 16, for example, t < 0.3w. Furthermore, from the viewpoint of reducing the contact area with the sealing body portion 12 when the rotor 4 is displaced, the end portion of each rotor fin portion 20 can have a pointed shape (a shape in which the thickness decreases as it moves radially outward). In this case, the end face 20t on the end side of each rotor fin portion 20 can include an inclined surface 20t1, which, from the viewpoint of suppressing the increase of leakage flow in the gap g, is inclined in a manner that moves radially outward and towards the upstream side in the axial direction.

[0047] According to the rotating machinery 2 described above, since it has multiple stationary fin sections 18 and multiple rotor fin sections 20, the contact area between the outer peripheral surface 4a of the rotor 4 and the inner peripheral surface 12a of the sealing body section 12 can be reduced when the rotor 4 is displaced in a direction orthogonal to the axial direction, compared to the case where it does not have multiple stationary fin sections 18 and multiple rotor fin sections 20. Therefore, the risk of contact between the rotor 4 and the stationary wall surface, i.e., the risk of thermal bending of the rotor 4 caused by frictional heat between the outer peripheral surface 4a of the rotor 4 and the inner peripheral surface 12a of the sealing body section 12, can be reduced.

[0048] And, as Figure 3 As indicated by arrow F1, the swirling flow (leakage flow) passing through the gap g between the outer peripheral surface 4a of the rotor 4 and the inner peripheral surface 12a of the sealing body 12 easily flows into the hole 16 of the inner peripheral surface 12a of the sealing body 12 along the rotor fin portion 20. Furthermore, as... Figure 4 (express Figure 3 As shown by arrow F2 in a schematic diagram of a portion of section AA, the swirling flow is redirected within the hole 16 to become a reverse swirling flow flowing in the opposite direction to the rotation direction r of the rotor 4 and flows out of the hole 16, thereby reducing the swirling flow. Therefore, the excitation force component (the component in the direction orthogonal to the axial direction) of the fluid force acting on the outer peripheral surface 4a of the rotor 4 can be reduced, and the damping effect of the shaft vibration of the rotor 4 can be improved, thus achieving high shaft stability of the rotor 4.

[0049] Figure 5 It is for use Figures 1-4The diagram illustrates a comparison of the flow rate (hereinafter referred to as "leakage flow rate") of the leakage flow through the gap g with the effective attenuation of the shaft vibration of the rotor 4 in the rotating machinery 2 described in the embodiments described. Here, comparison method 1 corresponds to a structure in which multiple stationary fin portions 18 and multiple rotor fin portions 20 are removed from the rotating machinery 2; comparison method 2 corresponds to a structure in which the height of the inner circumferential surface 12a of the sealing body portion 12 from the outer circumferential surface 4a of the rotor 4 is reduced relative to comparison method 1; comparison method 3 corresponds to a structure in which the height of the inner circumferential surface 12a of the sealing body portion 12 from the outer circumferential surface 4a of the rotor 4 is reduced relative to comparison method 2; and comparison method 4 corresponds to a structure in which the height of the inner circumferential surface 12a of the sealing body portion 12 from the outer circumferential surface 4a of the rotor 4 is reduced relative to comparison method 3. Furthermore, the height of the inner circumferential surface 12a of the sealing body portion 12 from the outer circumferential surface 4a of the rotor 4 in the above embodiments is the same as the height of the inner circumferential surface 12a of the sealing body portion 12 from the outer circumferential surface 4a of the rotor 4 in comparison method 1.

[0050] like Figure 5 As shown, in comparison methods 1 to 4, if the height of the inner circumferential surface 12a of the sealing body 12 from the outer circumferential surface 4a of the rotor 4 is increased in order to reduce the risk of contact between the rotor 4 and the inner circumferential surface 12a of the sealing body 12 (i.e., from comparison method 4 towards comparison method 1), it can be seen that while the leakage flow increases, the effective attenuation of shaft vibration decreases. Therefore, it can be seen that in comparison methods 1 to 4, it is difficult to simultaneously reduce the risk of contact between the rotor 4 and the inner circumferential surface 12a of the sealing body 12 and improve the attenuation effect of shaft vibration.

[0051] In contrast, in the rotating machinery 2 described in the above embodiment, although the height of the inner circumferential surface 12a of the sealing body 12 from the outer circumferential surface 4a of the rotor 4 is the same as that in comparison method 1, which has the highest height among comparison methods 1 to 4, a significant reduction in leakage flow rate and a large effective attenuation can be achieved compared to each of comparison methods 1 to 4. Therefore, the risk of contact between the rotor 4 and the inner circumferential surface 12a of the sealing body 12 can be reduced while achieving high axial stability of the rotor 4.

[0052] Figure 6 This is a graph showing the relationship between the axial position in the gap g between the outer peripheral surface 4a of the rotor 4 and the inner peripheral surface 12a of the sealing body 12 and the dimensionless circumferential velocity of the swirling flow (leakage flow) for each of the above embodiments and comparison method 1. Here, the dimensionless circumferential velocity is a value obtained by dividing the circumferential velocity at each position by the circumferential velocity at the 0mm axial position.

[0053] like Figure 6As shown, according to the above embodiment, compared with Comparison Method 1, since the swirl ratio can be reduced within the range where the hole 16 is formed in the axial direction, the shaft vibration of the rotor 4 can be effectively attenuated.

[0054] Figure 7 This is a schematic diagram showing another example of a cross-section along the axial direction of a rotating machine 2 according to one embodiment. Figure 7 In the rotating machinery 2 shown, unless otherwise specified, it is similar to... Figure 2 The common symbolic representations of the structures shown are as follows: Figure 2 The structures shown are identical, and their descriptions are omitted.

[0055] In several implementations, for example, Figure 7 As shown, each of the plurality of stationary fin portions 18 can be inclined in a manner that is radially inward and axially upstream. Furthermore, each of the plurality of rotor fin portions 20 can be inclined in a manner that is radially outward and axially upstream. In the illustrated exemplary embodiment, each of the rotor fin portions 20 protrudes towards the upstream wall surface 16a1 of the inner surface 16a of the corresponding hole 16. Specifically, as... Figure 7 As shown, if the straight line connecting the base end of the rotor fin portion 20 (in the illustrated example, the upstream end of the axial direction of the base end of the rotor fin portion 20) and the end of the rotor fin portion 20 is set as L in a cross section along the axial direction, then each rotor fin portion 20 is formed such that the wall surface 16a1 on the upstream side of the inner surface 16a of the hole 16 corresponding to the rotor fin portion 20 intersects the straight line L.

[0056] according to Figure 7 The structure shown enhances the effect of the contraction flow caused by each of the stationary fin portion 18 and the rotor fin portion 20, thereby effectively reducing the leakage flow in the gap g between the outer peripheral surface 4a of the rotor 4 and the inner peripheral surface 12a of the sealing body portion 12. For example, as Figure 8A As shown, compared to the case where the stationary fin portion 18 is not inclined relative to the radial direction, as Figure 8B As shown, when the stationary fin section 18 is inclined in a manner that it is directed towards the radially inward side and towards the axial upstream side, the flow near the end of the stationary fin section 18 is bent, and the downward velocity component becomes stronger. Therefore, the counterflow region near the end of the stationary fin section 18 becomes larger, which can reduce the effective cross-sectional area of ​​the leakage flow. Furthermore, as Figure 8C As indicated by arrow F3, on the axial section, the axial leakage flow in the gap g can be diverted by the rotor fin portion 20 and swirl within the hole 16 to effectively reduce the leakage flow.

[0057] Figure 9 It is Figure 7The leakage flow rate and effective attenuation of the shaft vibration of rotor 4 in the illustrated embodiment are related to Figure 2 The diagram illustrates the implementation method shown and compares it with the comparison methods 1 to 4 described above. (See diagram for example.) Figure 9 As shown, in Figure 7 In the illustrated embodiment, compared to each of comparison methods 1 to 4, it is possible to significantly reduce leakage flow while achieving large effective attenuation, thus balancing the reduction of the contact risk between the rotor 4 and the inner circumferential surface 12a of the sealing body 12 with the improvement of the attenuation effect of the rotor 4's shaft vibration. Furthermore, compared to... Figure 2 The implementation method shown (reference) Figure 5 Compared to [previous method], the effect of reducing leakage flow is further improved.

[0058] Figure 10 This is a schematic diagram showing another example of a cross-section along the axial direction of a rotating machine 2 according to one embodiment. Figure 10 In the rotating machinery 2 shown, unless otherwise specified, it is similar to... Figure 2 The common symbolic representations of the structures shown are as follows: Figure 2 The structures shown are identical, and their descriptions are omitted.

[0059] exist Figure 10 In the cross-section shown, the plurality of stationary fin portions 18 formed on the inner peripheral surface 12a of the sealing body portion 12 are sequentially referred to as stationary fin portions 18a, 18b, 18c, 18d, and 18e from the upstream side of the axial direction, and the plurality of rotor fin portions 20 formed on the outer peripheral surface 4a of the rotor 4 are sequentially referred to as rotor fin portions 20a, 20b, 20c, and 20d from the upstream side of the axial direction. Therefore, stationary fin portion 18b is located on the downstream side of the axial direction more than stationary fin portion 18a, stationary fin portion 18c is located on the downstream side of the axial direction more than stationary fin portion 18b, stationary fin portion 18d is located on the downstream side of the axial direction more than stationary fin portion 18c, and stationary fin portion 18e is located on the downstream side of the axial direction more than stationary fin portion 18d. Furthermore, rotor fin portion 20a is located between stationary fin portion 18a and stationary fin portion 18b, rotor fin portion 20b is located between stationary fin portion 18b and stationary fin portion 18c, rotor fin portion 20c is located between stationary fin portion 18c and stationary fin portion 18d, and rotor fin portion 20d is located between stationary fin portion 18d and stationary fin portion 18e.

[0060] exist Figure 10 In the cross-section shown, the plurality of holes 16 formed on the inner peripheral surface 12a of the sealing body portion 12 include holes 161 formed in the axial direction between the stationary fin portion 18a and the stationary fin portion 18b, and holes 162 formed in the axial direction between the stationary fin portion 18b and the stationary fin portion 18cb. Furthermore, in Figure 10On the cross-section shown, the inner peripheral surface 12a of the seal main body portion 12 includes a hole non-formation region 12a1 where no hole 16 is formed between the stationary fin portions 18c and 18d in the axial direction, and includes a hole non-formation region 12a2 where no hole 16 is formed between the stationary fin portions 18d and 18e in the axial direction.

[0061] On Figure 10 On the cross-section shown, the rotor fin portion 20a is axially disposed at the central position of the hole 161 and protrudes toward the bottom surface 16s of the hole 161. The rotor fin portion 20b is axially disposed at the central position of the hole 16i and protrudes toward the bottom surface 16s of the hole 162. The rotor fin portion 20c is axially disposed at the central position of the hole non-formation region 12a1 and protrudes toward the hole non-formation region 12a1. The rotor fin portion 20d is axially disposed at the central position of the hole non-formation region 12a2 and protrudes toward the hole non-formation region 12a2. On Figure 10 On the cross-section shown, the distance between the inner peripheral surface 12a of the seal main body portion 12 and the rotor fin portion 20a is set as d1, the distance between the inner peripheral surface 12a of the seal main body portion 12 and the rotor fin portion 20b is set as d2, the distance between the inner peripheral surface 12a of the seal main body portion 12 and the rotor fin portion 20c is set as d3, and the distance between the inner peripheral surface 12a of the seal main body portion 12 and the rotor fin portion 20d is set as d4, then d1 = d2, d2 < d3, and d3 = d4 are satisfied. In addition, the distance d1 corresponds to the distance between the bottom surface 16s of the hole 161 and the rotor fin portion 20a, the distance d2 corresponds to the distance between the bottom surface 16s of the hole 162 and the rotor fin portion 20b, the distance d3 corresponds to the distance between the hole non-formation region 12a1 and the rotor fin portion 20c, and the distance d4 corresponds to the distance between the hole non-formation region 12a2 and the rotor fin portion 20d.

[0062] According to Figure 10 the structure shown, compared with the case where holes 16 are formed between all the stationary fin portions 18 in the axial direction on the inner peripheral surface 12a of the seal main body portion 12, by providing the hole non-formation regions 12a1 and 12a2 and simultaneously providing the rotor fin portions 20c and 20d that respectively protrude toward the hole non-formation regions 12a1 and 12a2, the leakage flow rate in the gap g between the outer peripheral surface 4a of the rotor 4 and the inner peripheral surface 12a of the seal main body portion 12 can be reduced. And, compared with the case where there are no holes 16, the attenuation effect of the shaft vibration of the rotor 4 can be improved to achieve high shaft stability of the rotor 4.

[0063] The present invention is not limited to the above-described embodiments, and also includes embodiments obtained by adding modifications to the above-described embodiments, or embodiments obtained by appropriately combining these embodiments.

[0064] For example, in the above embodiments, the radially orthogonal cross-section of each of the holes 16 is illustrated as circular, but the radially orthogonal cross-section of each of the holes 16 can be quadrilateral. That is, each of the holes 16 can be a bottomed recess forming a quadrangular prism-shaped cavity. This facilitates the redirection of flow within the holes 16 and enhances the aforementioned effect of reducing swirling flow.

[0065] Furthermore, the housing body 8, the sealing body 12, and the stationary fin part 18 do not need to be configured as separate components; these arbitrary combinations can also be configured as a single component.

[0066] Furthermore, each of the plurality of stationary fin portions 18 may be configured to span the plurality of holes 16. That is, in a radial view, each of the plurality of stationary fin portions 18 may be configured to overlap with at least a portion of the plurality of holes 16.

[0067] Furthermore, for example, it could be one of the stationary fin portions 18 of the sealing device 10 located between two circumferentially adjacent holes 16 on the inner circumferential surface 12a of the sealing body portion 12, or it could be any number of stationary fin portions 18 of the sealing device 10 located between two circumferentially adjacent holes 16 on the inner circumferential surface 12a of the sealing body portion 12.

[0068] Furthermore, it is possible that only one of all the stationary fin portions 18 of the sealing device 10 is inclined in a manner that is towards the upstream side of the rotation direction r of the rotor 4 as it moves towards the radially inward side, or any number of the stationary fin portions 18 of the sealing device 10 are inclined in a manner that is towards the upstream side of the rotation direction r of the rotor 4 as it moves towards the radially inward side.

[0069] Furthermore, it is possible that only one of the rotor fin portions 20 of the rotating machinery 2 is inclined in a manner that is towards the upstream side of the rotation direction r of the rotor 4 as it moves towards the radially outward, or any number of stationary fin portions 18 of all the rotor fin portions 20 of the sealing device 10 are inclined in a manner that is towards the upstream side of the rotation direction r of the rotor 4 as it moves towards the radially outward.

[0070] Furthermore, for example, each of the plurality of stationary fin portions 18 of the sealing device 10 may be inclined in a manner that moves towards the upstream side of the rotation direction r of the rotor 4 in a radially inward direction, and each of the plurality of rotor fin portions 20 may extend radially (along a plane orthogonal to the axial direction). Alternatively, each of the plurality of stationary fin portions 18 of the sealing device 10 may extend radially (along a plane orthogonal to the axial direction), and each of the plurality of rotor fin portions 20 may be inclined in a manner that moves towards the upstream side of the rotation direction r of the rotor 4 in a radially outward direction.

[0071] The contents described in the above embodiments are as follows.

[0072] (1) The rotating machinery (e.g., rotating machinery 2) according to at least one embodiment of the present invention comprises:

[0073] Rotor (e.g., rotor 4);

[0074] The annular sealing body (e.g., sealing body 12) includes a stationary wall surface, i.e. an inner peripheral surface (e.g., inner peripheral surface 12a), opposite to the outer peripheral surface (e.g., outer peripheral surface 4a) of the rotor, and a plurality of holes (e.g., a plurality of holes 16) formed on the inner peripheral surface.

[0075] Multiple stationary fin portions (e.g., the aforementioned multiple stationary fin portions 18) are spaced apart on the inner circumferential surface along the axial direction of the rotor; and

[0076] At least one first rotor fin portion (e.g., the aforementioned plurality of rotor fin portions 20 or rotor fin portions 20a, 20b) is disposed on the outer peripheral surface of the rotor.

[0077] Each of the plurality of stationary fin portions extends circumferentially along the rotor and protrudes from the inner circumferential surface toward the outer circumferential surface of the rotor.

[0078] Each of the at least one first rotor fin portion extends along the circumferential direction and protrudes from the outer circumferential surface of the rotor toward the hole.

[0079] According to the rotating machinery described in (1) above, by having multiple stationary fins and at least one rotor fin, the contact area between the outer peripheral surface of the rotor and the stationary wall when the rotor is displaced in a direction orthogonal to the axial direction can be reduced. Therefore, the risk of contact between the rotor and the stationary wall, i.e. the risk of thermal bending of the rotor caused by the frictional heat between the outer peripheral surface of the rotor and the stationary wall, can be reduced.

[0080] Furthermore, the swirling flow (leakage flow) passing through the gap between the outer circumferential surface of the rotor and the inner circumferential surface (stationary wall surface) of the sealing body easily flows into the hole on the inner circumferential surface of the sealing body along the rotor fin portion. The swirling flow is turned within the hole, becoming a reverse swirling flow flowing in the opposite direction to the rotor's rotation and exiting from the hole. This reduces the swirling flow and decreases the excitation force component (the component orthogonal to the axial direction) of the fluid force acting on the outer circumferential surface of the rotor. Therefore, the damping effect of the rotor's shaft vibration can be improved, achieving high shaft stability of the rotor.

[0081] (2) In several embodiments, in the rotating machinery described in (1) above,

[0082] The thickness of each of the plurality of stationary fin portions is less than the size of the hole in the axial direction.

[0083] According to the rotating machinery described in (2) above, the risk of contact between the rotor and the stationary wall can be reduced while achieving high axial stability of the rotor.

[0084] (3) In several embodiments, in the rotating machinery described in (1) or (2) above,

[0085] At least one of the plurality of stationary fin portions is disposed on the inner circumferential surface of the sealing body portion between two adjacent holes along the axial direction.

[0086] According to the rotating machinery described in (3) above, by providing an axial fin portion at a position between two axially adjacent holes on the inner circumferential surface of the sealing body, the stationary fin portion can be firmly fixed to the sealing body compared to the case where the stationary fin portion is provided in a manner that spans the holes.

[0087] (4) In several embodiments, in any of the rotating machines described in (1) to (3) above,

[0088] The first rotor fin portion is located at the center of the hole in the axial direction.

[0089] According to the rotating machinery described in (4) above, by providing a first rotor fin portion at the central position of the hole in the axial direction, even if the relative position of the first rotor fin portion relative to the hole in the axial direction changes due to the axial thermal elongation difference between the stationary wall and the rotor, it can be configured as a robust structure that can suppress the reduction of sealing performance such as a sharp decrease in effective attenuation or a sharp increase in leakage flow.

[0090] (5) In several embodiments, in any of the rotating machines described in (1) to (4) above,

[0091] The cross-section in the hole that is radially orthogonal to the rotor is circular.

[0092] According to the rotating machinery described in (5) above, by setting the shape of the cross section in the hole that is radially orthogonal to the rotor to a circle, it is possible to promote the deflection of the flow in the hole and improve the effect of reducing the swirling flow described in (1) above.

[0093] (6) In several embodiments, in any of the rotating machines described in (1) to (5) above,

[0094] The cross-section in the hole that is radially orthogonal to the rotor has a quadrilateral shape.

[0095] According to the rotating machinery described in (6) above, by setting the shape of the cross section in the hole that is radially orthogonal to the rotor to a quadrilateral, it is possible to promote the deflection of the flow in the hole and improve the effect of reducing the swirling flow described in (1) above.

[0096] (7) In several embodiments, in any of the rotating machines described in (1) to (6) above,

[0097] At least one of the plurality of stationary fin portions is inclined in such a manner as it moves toward the radially inward side of the rotor and toward the axially upstream side.

[0098] According to the rotating machinery described in (7) above, the effect of the contraction flow caused by the stationary fin section can be improved, thereby reducing the flow rate of the leakage flow flowing in the gap between the outer peripheral surface of the rotor and the stationary wall.

[0099] (8) In several embodiments, in any of the rotating machines described in (1) to (7) above,

[0100] The first rotor fin portion is inclined in such a way that it is directed toward the upstream side of the axial direction as it is directed toward the radially outer side of the rotor.

[0101] According to the rotating machinery described in (8) above, the effect of the contraction flow caused by the first rotor fin portion can be improved, thereby reducing the flow rate of the leakage flow flowing in the gap between the outer peripheral surface of the rotor and the stationary wall.

[0102] (9) In several embodiments, in any of the rotating machines described in (1) to (8) above,

[0103] The end portion of the first rotor fin has a pointed shape.

[0104] According to the rotating machinery described above (9), since the contact area between the first rotor fin portion and the sealing body portion when the rotor is displaced in a direction orthogonal to the axial direction can be reduced, the risk of contact between the rotor and the stationary wall surface can be reduced, that is, the risk of thermal bending of the rotor caused by the frictional heat between the outer peripheral surface of the rotor and the stationary wall surface.

[0105] (10) In several embodiments, in any of the rotating machines described in (1) to (9) above,

[0106] The plurality of stationary fin portions include: a first stationary fin portion (e.g., stationary fin portion 18a or stationary fin portion 18b described above); a second stationary fin portion (e.g., stationary fin portion 18b or stationary fin portion 18c described above), located downstream in the axial direction than the first stationary fin portion; a third stationary fin portion (e.g., stationary fin portion 18c or stationary fin portion 18d described above), located downstream in the axial direction than the second stationary fin portion; and a fourth stationary fin portion (e.g., stationary fin portion 18d or stationary fin portion 18e described above), located downstream in the axial direction than the third stationary fin portion.

[0107] The plurality of holes include holes formed in the range between the first stationary fin portion and the second stationary fin portion in the axial direction (e.g., hole 161 or hole 162 mentioned above).

[0108] The inner circumferential surface of the sealing body includes a hole-free region (e.g., the aforementioned hole-free region 12a1 or hole-free region 12a2) between the third stationary fin portion and the fourth stationary fin portion in the axial direction.

[0109] The rotating machinery includes a second rotor fin portion (e.g., rotor fin portion 20c or rotor fin portion 20d) disposed on the outer peripheral surface of the rotor at a position between the third stationary fin portion and the fourth stationary fin portion in the axial direction.

[0110] The second rotor fin extends along the circumferential direction and protrudes toward the area where the hole is not formed on the inner circumferential surface.

[0111] According to the rotating machinery described above (10), compared to the case where holes are formed between all stationary fin portions in the axial direction on the inner circumferential surface of the sealing body, by providing a second rotor fin portion protruding towards the area where holes are not formed while simultaneously providing the area where holes are not formed, the flow rate of leakage flow flowing in the gap between the outer circumferential surface of the rotor and the stationary wall surface can be reduced. Furthermore, compared to the case without holes, the damping effect of rotor shaft vibration can be improved, thereby achieving high shaft stability of the rotor.

[0112] (11) In several embodiments, in the rotating machinery described in any of the embodiments (1) to (10) above,

[0113] Each of the first rotor fins is formed in a cross section along the axial direction such that a straight line connecting the base end of the first rotor fin to the end of the first rotor fin intersects the wall surface on the inner surface of the hole corresponding to the first rotor fin on the axial upstream side.

[0114] According to the rotating machinery described above (11), on the cross section along the axial direction, the axial leakage flow in the gap between the outer peripheral surface of the rotor and the inner peripheral surface of the sealing body can be turned by the first rotor fin portion and swirled in the hole, which can effectively reduce the flow rate of the leakage flow.

[0115] Symbol Explanation

[0116] 2-Rotating machinery, 4-Rotor, 4a-Outer peripheral surface, 6-Shell, 8-Shell body, 8a-Inner surface, 10-Sealing device, 12-Sealing body, 12a-Inner peripheral surface, 12a1, 12a2-Areas where holes are not formed, 12b-Outer peripheral surface, 16-Hole, 16a-Inner surface, 16a1-Wall surface, 16s-Bottom surface, 18, 18a, 18b, 18c, 18d, 18e-Stationary finned parts, 20, 20a, 20b, 20c, 20d-Rotor finned parts, L-Straight line, Pc-Position, d1, d2, d3, d4-Distance, g-Clearance, r-Direction of rotation, w-Dimension.

Claims

1. A rotating machine comprising: Rotor; The annular sealing body includes a stationary wall surface, i.e. an inner circumferential surface, facing the outer circumferential surface of the rotor, and a plurality of holes formed in the inner circumferential surface; Multiple stationary fins are spaced apart along the axial direction of the rotor on the inner circumferential surface; and At least one first rotor fin portion is disposed on the outer peripheral surface of the rotor. Each of the plurality of stationary fin portions extends circumferentially along the rotor and protrudes from the inner circumferential surface toward the outer circumferential surface of the rotor. Each of the at least one first rotor fin portion extends along the circumferential direction and protrudes from the outer circumferential surface of the rotor toward the hole.

2. The rotating machinery according to claim 1, wherein, The thickness of each of the plurality of stationary fin portions is less than the size of the hole in the axial direction.

3. The rotating machinery according to claim 1, wherein, At least one of the plurality of stationary fin portions is disposed on the inner circumferential surface of the sealing body portion between two adjacent holes along the axial direction.

4. The rotating machinery according to claim 1, wherein, The first rotor fin portion is located at the center of the hole in the axial direction.

5. The rotating machinery according to claim 1, wherein, The cross-section in the hole that is radially orthogonal to the rotor is circular.

6. The rotating machinery according to claim 1, wherein, The cross-section in the hole that is radially orthogonal to the rotor has a quadrilateral shape.

7. The rotating machinery according to claim 1, wherein, At least one of the plurality of stationary fin portions is inclined in such a manner as it moves toward the radially inward side of the rotor and toward the axially upstream side.

8. The rotating machinery according to claim 1, wherein, The first rotor fin portion is inclined in such a way that it is directed toward the upstream side of the axial direction as it is directed toward the radially outer side of the rotor.

9. The rotating machinery according to claim 1, wherein, The end portion of the first rotor fin has a pointed shape.

10. The rotating machinery according to claim 1, wherein, The plurality of stationary fin portions include: a first stationary fin portion; a second stationary fin portion located downstream of the first stationary fin portion in the axial direction; a third stationary fin portion located downstream of the second stationary fin portion in the axial direction; and a fourth stationary fin portion located downstream of the third stationary fin portion. The plurality of holes include those formed within the range between the first stationary fin portion and the second stationary fin portion in the axial direction. The inner circumferential surface of the sealing body includes a region in the axial direction between the third stationary fin portion and the fourth stationary fin portion where no hole is formed. The rotating machinery includes a second rotor fin portion disposed on the outer peripheral surface of the rotor at a position between the third stationary fin portion and the fourth stationary fin portion in the axial direction. The second rotor fin extends along the circumferential direction and protrudes toward the area where the hole is not formed on the inner circumferential surface.

11. The rotating machinery according to claim 1, wherein, In a cross section along the axial direction, each of the first rotor fins is formed such that a straight line connecting the base end of the first rotor fin and the end of the first rotor fin intersects with the wall surface on the inner surface of the hole corresponding to the first rotor fin in the axial direction.

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