Rotating machine sliding component, rotating machine equipped with said rotating machine sliding component, rotating machine, and method for manufacturing said rotating machine sliding component

Abstract

To prevent a surface treatment layer from being peeled at an end part of a sliding surface formed in a rotary machine in order to improve the service life of the surface treatment layer.SOLUTION: A sliding component for a rotary machine that is supported on either a fixed side or a rotation side of the rotary machine comprises a facing surface arranged to face the other side component supported on the other side of the fixed side and the rotation side of the rotary machine, a sliding surface formed on at least a part of the facing surface and configured to slide against the other side component, and a surface treatment layer formed by subjecting the sliding surface to surface treatment. An end part of the sliding surface is formed with a base material exposed part where a base material not subjected to the surface treatment is exposed.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a sliding component for a rotating machine, a rotating machine including the sliding component for a rotating machine, a rotating machine, and a method for manufacturing the sliding component for a rotating machine. [Background technology]

[0002] In rotating machines such as pumps that incorporate a rotor such as an impeller inside a casing, sliding parts are formed between rotating members such as the rotor or a rotating shaft that supports the rotor, and a fixed member such as the casing. The sliding surfaces formed in the sliding parts are prone to wear, pitting, erosion, etc., and as a countermeasure against this, it has been proposed to apply surface treatments such as thermal spraying, DCL (diamond-like carbon) coating, nitriding, plating, etc. to improve the corrosion resistance and wear resistance of the sliding surfaces (see Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 10-184692 [Patent Document 2] JP 2012-166237 A Summary of the Invention [Problem to be solved by the invention]

[0004] The surface treatment layer formed on the sliding surface by surface treatment has high hardness but is brittle. Therefore, the surface treatment layer is likely to peel off at the corners formed at the ends of the sliding surface, which may shorten the life of the surface treatment layer. In particular, thread seals with angular grooves have many corners, and chipping of the surface treatment may be a problem.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and aims to improve the life of a surface treatment layer by suppressing peeling of the surface treatment layer at the end of a sliding surface formed in a rotating machine. [Means for solving the problem]

[0006] In view of the above circumstances, a sliding component for a rotating machine according to at least one embodiment of the present invention is a sliding component for a rotating machine supported on either a fixed side or a rotating side of a rotating machine, an opposing surface that is disposed opposite to a second-side component that is supported on the other of the fixed side or the rotating side of the rotary machine; a sliding surface formed on at least a part of the opposing surface and configured to slide against the other-side component; a surface treatment layer formed by subjecting the sliding surface to a surface treatment, At the end of the sliding surface, a base material exposed portion is formed where the base material that has not been subjected to the surface treatment is exposed.

[0007] Moreover, the sliding part for a rotating machine according to at least one embodiment of the present invention comprises: A sliding component for a rotating machine that is supported on either a fixed side or a rotating side of the rotating machine, an opposing surface that is disposed opposite to a second-side component that is supported on the other of the fixed side or the rotating side of the rotary machine; a sliding surface formed on at least a part of the opposing surface and configured to slide against the other-side component; A surface treatment layer formed by performing a surface treatment on the entire sliding surface, The sliding surface includes an end portion formed by performing a chamfering process.

[0008] Moreover, the rotary machine according to at least one embodiment of the present invention includes: A rotating machine having a sliding part formed on either a fixed side or a rotating side of the rotating machine, The sliding portion is an opposing surface that is disposed opposite to a second-side component that is supported on the other of the fixed side or the rotating side of the rotary machine; a sliding surface formed on at least a part of the opposing surface and configured to slide against the other-side component; a surface treatment layer formed by subjecting the sliding surface to a surface treatment, At the end of the sliding surface, a base material exposed portion is formed where the base material that has not been subjected to the surface treatment is exposed.

[0009] Moreover, the rotary machine according to at least one embodiment of the present invention includes: A rotating machine having a sliding part formed on either a fixed side or a rotating side of the rotating machine, The sliding portion is an opposing surface that is disposed opposite to a second-side component that is supported on the other of the fixed side or the rotating side of the rotary machine; a sliding surface formed on at least a part of the opposing surface and configured to slide against the other-side component; A surface treatment layer formed by performing a surface treatment on the entire sliding surface, The sliding surface includes an end portion formed by performing a chamfering process.

[0010] Further, a method for producing a sliding part for a rotary machine according to at least one embodiment of the present invention includes the steps of: A method for manufacturing a sliding component for a rotating machine that is supported on either a fixed side or a rotating side of the rotating machine, comprising the steps of: A preparation step of preparing a sliding component before machining; a groove processing step of processing a groove on one surface of the unprocessed sliding component; a surface treatment process for performing a surface treatment on a predetermined region of the one surface including a bottom surface of the groove of the unmachined sliding component; a cutting step of cutting the one surface of the unmachined sliding component to form at least one convex portion, the cutting step being such that the surface treatment layer formed on the bottom surface of the groove is located in a central portion of a convex surface of the at least one convex portion excluding an end portion; Equipped with.

[0011] Further, a method for producing a sliding part for a rotary machine according to at least one embodiment of the present invention includes the steps of: A method for manufacturing a sliding component for a rotating machine that is supported on either a fixed side or a rotating side of the rotating machine, comprising the steps of: a preparation step of preparing an unmachined sliding component having a protrusion formed on one surface thereof; a processing step of processing a central portion of the convex surface of the convex portion, excluding the end portions, into a concave shape; a surface treatment step of performing a surface treatment on the convex surface processed into the concave shape; a cutting step of cutting off the end portion of the convex surface processed into the concave shape; Equipped with. Effect of the Invention

[0012] According to at least one embodiment of the present invention, peeling of the surface treatment layer at the end of the sliding surface formed in the rotary machine can be suppressed, thereby improving the life of the surface treatment layer. [Brief description of the drawings]

[0013] [Figure 1] 1 is a vertical sectional view of a rotary machine according to an embodiment; [Figure 2A] FIG. 2 is an enlarged view of a sliding component for a rotary machine (impeller) according to one embodiment. [Figure 2B] FIG. 2 is an enlarged view of a rotating machine sliding component (balance sleeve) according to one embodiment. [Figure 2C] FIG. 2 is an enlarged view of a sliding component (liner ring) for a rotary machine according to one embodiment. [Figure 2D] FIG. 2 is an enlarged view of a sliding component for a rotary machine (ring-shaped member) according to one embodiment. [Diagram 3] 2A to 2C, showing a sliding surface of a sliding component for a rotating machine according to one embodiment. FIG. [Figure 4A] 4 is a cross-sectional view showing the sliding component for a rotating machine according to one embodiment, the cross-sectional view corresponding to an enlarged view of part B in FIG. [Figure 4B] 4 is a cross-sectional view showing the sliding component for a rotating machine according to one embodiment, the cross-sectional view corresponding to an enlarged view of part B in FIG. [Figure 5A] 4 is a cross-sectional view showing the sliding component for a rotating machine according to one embodiment, the cross-sectional view corresponding to an enlarged view of part B in FIG. [Figure 5B] 4 is a cross-sectional view showing the sliding component for a rotating machine according to one embodiment, the cross-sectional view corresponding to an enlarged view of part B in FIG. [Figure 6] FIG. 2 is a flowchart showing a method for manufacturing a sliding component for a rotating machine according to one embodiment. [Figure 7] 1A to 1C are schematic diagrams showing a method for manufacturing a sliding component for a rotating machine according to one embodiment in the order of steps. [Figure 8] FIG. 2 is a flowchart showing a method for manufacturing a sliding component for a rotating machine according to one embodiment. [Figure 9] 2A to 2C are schematic diagrams illustrating process preparation in a method for producing a sliding component for a rotating machine according to one embodiment. [Figure 10] FIG. 2 is a vertical sectional view of a rotary machine according to one embodiment, showing a rotary machine according to an embodiment different from that shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of components described as the embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the present invention.

[0015] <Configuration of rotating machines> Fig. 1 is a vertical cross-sectional view showing a rotating machine including a rotating machine sliding component according to one embodiment. In this embodiment, a case where the rotating machine is a centrifugal pump 10 (10A) will be described as an example. The centrifugal pump 10 (rotating machine) is a horizontal multi-stage pump, and a plurality of inner casings 12 are arranged inside an outer casing (not shown) along the axis X direction of a main shaft 14. In Fig. 1, the left side is the upstream side in the flow direction of a fluid (e.g., boiler feed water), and the right side is the downstream side.

[0016] The inner casing 12 accommodates impellers 16 each having a plurality of blades 18. Each impeller 16 is attached to a main shaft 14 that is driven to rotate by a prime mover (not shown). In each impeller 16, the plurality of blades 18 are arranged along the circumferential direction of the main shaft 14, and each blade is arranged radially toward the outside in the radial direction of the main shaft 14. Each impeller 16 has an annular shroud portion 16A connected to the tip side of the plurality of blades 18, an annular hub portion 16B connected to the base end side of the plurality of blades 18, and an annular sleeve portion 16C connected to the radial inner end of the hub portion 16B and attached to the main shaft 14. This impeller 16 is configured to rotate together with the main shaft 14. The impeller 16 constitutes some embodiments of the sliding part for a rotary machine according to the present disclosure, which is supported by the main shaft 14 (rotating side) of the centrifugal pump 10 (10A).

[0017] In the inner casing 12, guide vanes and return vanes (not shown) are arranged between each impeller 16. The fluid discharged from the outlet of the impeller 16 is decelerated by the volute and positive pressure restored (pressurized) before being guided to the subsequent impeller 16. A shroud end 16a extending substantially parallel to the main shaft 14 is formed on the inlet side of the impeller 16. The shroud end 16a is a part of the shroud portion 16A, and the inlet of the impeller 16 is defined by this shroud end 16a.

[0018] A balance sleeve 28, which is a member for suppressing the axial thrust of the centrifugal pump, is housed inside the inner casing 12. The balance sleeve 28 has an annular shape, and is attached to the main shaft 14 so as to rotate together with the main shaft 14. The balance sleeve 28 constitutes some embodiments of the sliding component for a rotating machine according to the present disclosure, which is supported by the main shaft 14 (rotating side) of the centrifugal pump 10 (10A).

[0019] In addition, a liner ring 24 having an annular shape surrounding the periphery of the shroud end 16a is fixed to the inner peripheral surface 12a of the inner casing 12. That is, the inner peripheral surface of the liner ring 24 and the outer peripheral surface of the shroud end 16a of the impeller 16 are disposed to face each other. The liner ring 24 is provided to prevent the fluid flowing out of the outlet of the impeller 16 together with the shroud end 16a from flowing back between the inner casing 12 and the impeller 16 and leaking to the inlet side of the impeller 16.

[0020] Additionally, a ring-shaped intermediate bushing 25 that surrounds the periphery of the sleeve portion 16C of the impeller 16 is fixed to the inner peripheral surface 12a of the inner casing 12. That is, the inner peripheral surface of the intermediate bushing 25 and the outer peripheral surface of the sleeve portion 16C of the impeller 16 are disposed opposite to each other. The intermediate bushing 25 is fixed inside the inner casing 12 and between adjacent impellers 16, and prevents fluid from leaking from the gap between the intermediate bushing 25 and the sleeve portion 16C.

[0021] Additionally, an annular balance bushing 26 is fixed to the inner peripheral surface 12a of the inner casing 12, surrounding the periphery of a balance sleeve 28 fixed to the outer peripheral surface of the main shaft 14. That is, the inner peripheral surface of the balance bushing 26 and the outer peripheral surface of the balance sleeve 28 are disposed opposite to each other. The balance bushing 26 is fixed inside the inner casing 12, and prevents fluid from leaking from the gap between the balance bushing 26 and the balance sleeve 28.

[0022] The liner ring 24, the intermediate bushing 25, and the balance bushing 26 constitute some embodiments of the sliding components for a rotary machine according to the present disclosure, which are supported on the inner casing 12 (fixed side) of the centrifugal pump 10 (10A).

[0023] <Configuration of sliding parts for rotating machines> FIG. 2A is an enlarged view of a rotating machine sliding component (impeller 16) according to one embodiment. FIG. 2B is an enlarged view of a rotating machine sliding component (balance sleeve 28) according to one embodiment. FIG. 2C is an enlarged view of a rotating machine sliding component (liner ring 24) according to one embodiment. FIG. 2D is an enlarged view of a rotating machine sliding component (ring-shaped member 27) according to one embodiment. FIG. 3 is a cross-sectional view corresponding to the enlarged view of part A in FIGS. 2A to 2D, showing a sliding surface of a rotating machine sliding component according to one embodiment. FIGS. 4A and 4B are cross-sectional views corresponding to the enlarged view of part B in FIG. 3, showing a rotating machine sliding component according to one embodiment. FIGS. 5A and 5B are cross-sectional views corresponding to the enlarged view of part B in FIG. 3, showing a rotating machine sliding component according to one embodiment.

[0024] 2A, the shroud end 16a of the impeller 16 has, on its outer circumferential surface, an opposing surface 30 (outer circumferential surface 16b) disposed opposite the inner circumferential surface of the liner ring 24. In addition, the sleeve portion 16C of the impeller 16 has, on its outer circumferential surface, an opposing surface 30 (outer circumferential surface 16c) disposed opposite the inner circumferential surface of the intermediate bushing 25.

[0025] As shown in FIG. 2B, the balance sleeve 28 has, on its outer circumferential surface, an opposing surface 30 (outer circumferential surface 28a) that is disposed opposite to the inner circumferential surface of the balance bushing 26 described above.

[0026] 2C, the liner ring 24 has, on its inner circumferential surface, an opposing surface 30 (inner circumferential surface 24a) disposed opposite the shroud end portion 16a of the impeller 16. Also, a convex portion 24b is formed on the outer circumferential surface of the liner ring 24. The liner ring 24 is positioned by fitting this convex portion 24b into a concave portion 12b formed on the inner circumferential surface 12a of the inner casing 12.

[0027] Although not shown, the intermediate bushing 25 has an opposing surface 30 on its inner peripheral surface that is disposed opposite to the outer peripheral surface of the sleeve portion 16C of the impeller 16. The intermediate bushing 25 has a positioning protrusion on its outer peripheral surface, similar to the liner ring 24. Although not shown, the balance bushing 26 has an opposing surface 30 on its inner peripheral surface that is disposed opposite to the outer peripheral surface of the balance sleeve 28.

[0028] As shown in FIG. 3, at least a portion of the opposing surface 30 of each of the impeller 16, balance sleeve 28, liner ring 24, intermediate bushing 25, and balance bushing 26 is formed with a sliding surface 34 configured to slide against the opposing other side component.

[0029] Here, the other side part refers to a part supported by the other of the inner casing 12 (fixed side) or the main shaft 14 (rotating side) of the centrifugal pump 10 (10A), and arranged opposite to the sliding part for a rotary machine supported by either the inner casing 12 (fixed side) or the main shaft 14 (rotating side). In the case where the shroud end 16a of the impeller 16 constitutes some embodiments of the sliding component for a rotary machine according to the present disclosure, the above-mentioned other side part is the liner ring 24 facing thereto. In the case where the sleeve portion 16C of the impeller 16 constitutes some embodiments of the sliding component for a rotary machine according to the present disclosure, the above-mentioned other side part is the intermediate bush 25 facing thereto. In the case where the balance sleeve 28 constitutes some embodiments of the sliding component for a rotary machine according to the present disclosure, the above-mentioned other side part is the balance bush 26 facing thereto. In the case where the liner ring 24 constitutes some embodiments of the sliding component for a rotary machine according to the present disclosure, the above-mentioned other side part is the shroud end 16a of the impeller 16 facing thereto. In the case where the intermediate bush 25 constitutes some embodiments of the sliding component for a rotary machine according to the present disclosure, the above-mentioned other side part is the sleeve portion 16C of the impeller 16 facing thereto. In the case where the balance bushing 26 constitutes some embodiments of the sliding component for a rotary machine according to the present disclosure, the above-mentioned other-side component is the opposing balance sleeve 28. In addition, as shown in Fig. 2D described later, in the case where the ring-shaped member 27 constitutes some embodiments of the sliding component for a rotary machine according to the present disclosure, the above-mentioned other-side component is the opposing liner ring 24.

[0030] Furthermore, as shown in FIGS. 4A, 4B, 5A, and 5B, a surface treatment layer 36 is formed on the sliding surface 34 by performing a surface treatment.

[0031] The surface treatment layer 36 is a surface-treated layer formed on the surface of the sliding surface 34. The surface treatment layer 36 is formed by, for example, a method of forming a coating having corrosion resistance and wear resistance on the surface of the base material 40 by thermal spraying, DCL coating, plating, or the like, or a method of imparting corrosion resistance and wear resistance to the surface layer of the base material 40 by nitriding, or the like.

[0032] In the sliding component for a rotary machine according to an embodiment of the present invention configured as described above, as shown in Figs. 4A and 4B, the base material exposed portion 40a is formed at both ends 34a (both corner groove ends 34a1) of the sliding surface 34 in the axial direction X, where the base material 40 is exposed and the surface treatment layer 36 is not formed without surface treatment. Since the base material exposed portion 40a is formed at both ends 34a (both corner groove ends 34a1) of the sliding surface 34 and the surface treatment layer 36 is not formed, the peeled portion caused by the peeling of the surface treatment layer 36 at both ends 34a (both corner groove ends 34a1) can be prevented from spreading, thereby improving the life of the surface treatment layer 36. Therefore, the operating time of the centrifugal pump 10 (10A) can be extended. The ends 34a of the present invention are not limited to the above-mentioned corner groove ends 34a1, but also include the ends 34a of the sliding surface 34 when no corner groove is formed.

[0033] In one embodiment, the base material exposed portion 40a may be a cut surface formed by cutting a part of the base material 40. By using cutting as a method for forming the base material exposed portion 40a, it becomes easy to form the base material exposed portion 40. Even in the case of surface treatment in which the surface treatment layer 36 is formed from the sliding surface 34 to a predetermined depth, the base material exposed portion 40a can be easily formed by cutting the formed surface treatment layer 36.

[0034] In one embodiment, the above-mentioned surface treatment may be a nitriding treatment. When the surface treatment layer 36 is formed by nitriding the surface layer of the base material 40 constituting the sliding surface 34, the surface treatment layer 36 can be formed inside the base material 40, which is less likely to peel off than when a coating layer is formed on the surface of the base material 40, such as by thermal spraying, DCL coating, plating, etc. In addition, by forming base material exposed parts 40a at both ends 34a (both corner groove ends 34a1) of the sliding surface 34, peeling of the surface treatment layer 36 can be further suppressed.

[0035] In one embodiment, as shown in Fig. 2C, both components arranged opposite to each other are configured as a rotary machine sliding component having the above-mentioned opposing surface 30, sliding surface 34, and surface treatment layer 36. In the embodiment shown in Fig. 2C, both the outer peripheral surface 16b of the shroud end 16a of the impeller 16 and the inner peripheral surface 24a of the liner ring 24 are configured as the above-mentioned opposing surface 30. In this case, wear of the rotating component can be suppressed by making the hardness of the surface treatment layer 36 of the rotating component (the shroud side end 16a of the impeller 16) higher than the hardness of the surface treatment layer 36 of the fixed component (the liner ring 24).

[0036] In one embodiment, as shown in FIG. 2D, only the rotating part of both parts arranged opposite to each other is configured as a rotary machine sliding part having the above-mentioned opposing surface 30, sliding surface 34, and surface treatment layer 36. In the embodiment shown in FIG. 2D, the inner circumferential surface 24a of the liner ring 24 is not configured as the above-mentioned opposing surface 30 (the surface treatment layer 36 is not formed on the sliding surface 34), and only the inner circumferential surface 27a of the ring-shaped member 27 supported on the outer circumferential surface of the shroud end portion 16a of the impeller 16 is configured as the above-mentioned opposing surface 30. This ring-shaped member 27 constitutes some embodiments of the rotary machine sliding part according to the present disclosure, which is supported on the impeller 16 (rotating side) of the centrifugal pump 10 (10A). In this way, by configuring only the rotating part of both parts arranged opposite to each other as a rotary machine sliding part, wear of the rotating part can be suppressed.

[0037] 2A to 2D and 3, the opposing surface 30 includes a thread groove region 42 in which a thread groove 44 and a thread 46 are formed, the thread groove region 42 extending helically along the axis X. In addition, as shown in FIG. 2C, when both components arranged opposite to each other are configured as sliding components for a rotary machine including the opposing surface 30, the sliding surface 34, and the surface treatment layer 36 described above, the thread groove region 42 may be formed only in the component on one side. 3, in the thread groove region 42, the top of the thread 46 is formed in a plane that is substantially parallel to the axis X, and the sliding surface 34 is configured by this plane. If such a thread groove region 42 is formed on the opposing surface 30, the sealing effect of the thread groove 44 as a labyrinth seal can be improved in the gap between the opposing surface 30 and the other side component.

[0038] In the thread groove region 42, when the base material exposed portions 40a are formed at both ends 34a (both corner groove ends 34a1) of the sliding surface 34 in the axis X direction, the base material exposed portions 40a are formed at both corner groove ends 34a in the axis X direction of each thread 46. The sliding surface 34 may be divided into a plurality of parts as shown in FIG. 3, or may be constituted by a single sliding surface 34 in an embodiment not shown.

[0039] In one embodiment, as shown in Fig. 4B, the surface treatment layer 36 is not formed on the side of the screw groove 44 or the screw thread 46, but is formed only in the central portion excluding both end portions 34a (both corner groove ends 34a1) of the sliding surface 34. Since the surface treatment layer 36 has a high hardness but is brittle, it is desirable to form the surface treatment layer 36 only in such a necessary portion. However, as shown in Fig. 4A, the surface treatment layer 36 may also be formed on the side of the screw groove 44 or the screw thread 46.

[0040] 5A and 5B, the sliding component for a rotating machine according to one embodiment of the present invention includes the above-mentioned opposing surface 30, sliding surface 34, and a surface treatment layer 36 formed by performing a surface treatment over the entire sliding surface 34. The sliding surface 34 has an end 34a (chamfered end 34a2) formed by performing a chamfering process.

[0041] According to this configuration, the sliding component for a rotating machine includes a surface treatment layer 36 formed by performing a surface treatment over the entire sliding surface 34, and an end 34a (chamfered end 34a2) formed by performing a chamfering process. In this way, by performing a chamfering process on the end 34a where the surface treatment layer 36 is likely to peel off, it is possible to prevent the spread of the peeled portion caused by the peeling of the surface treatment layer 36 at the end 34a, thereby improving the life of the surface treatment layer 36. Therefore, it is possible to improve the durability of a rotating machine equipped with the sliding component for a rotating machine.

[0042] 5A, the end 34a of the sliding surface 34 may have a C-chamfered shape. By making the end 34a of the sliding surface 34 have a C-chamfered shape, peeling of the surface treatment layer 36 at the end 34 can be further suppressed.

[0043] In one embodiment, as shown in Fig. 5B, the end 34a of the sliding surface 34 may have a R-chamfered shape. In this manner, the shape of the end 34a of the sliding surface 34 may be a R-chamfered shape, and is not particularly limited.

[0044] In the above embodiment, as one aspect, when the chamfer dimension of the end 34a is C and the width (axis X direction) dimension of the sliding surface 34 is D, C / D may be 0.025 to 0.250, preferably 0.050 to 0.250, and more preferably 0.100 to 0.250. In particular, when C / D is 0.100 or more, the end 34a (chamfered end 34a1) that has been subjected to chamfering having a predetermined size or more can be secured. Therefore, peeling of the surface treatment layer 36 at the end 34a of the sliding surface 34 can be easily suppressed. In addition, since C / D is 0.250 or less, the size of the sliding surface 34 that has not been subjected to chamfering can be secured. Therefore, the sealing performance of the sliding surface 34 can be easily maintained.

[0045] <Other rotating machine configurations> Fig. 10 is a vertical cross-sectional view of a rotary machine according to one embodiment, and shows a rotary machine (centrifugal pump) according to an embodiment different from that shown in Fig. 1. The centrifugal pump 10 (10B) according to this embodiment has a basically similar configuration to the above-described embodiment, and the same components are denoted by the same reference numerals and description thereof will be omitted.

[0046] In the embodiment shown in FIG. 1, the rotary machine sliding parts (impeller 16, balance sleeve 28, liner ring 24, intermediate bush 25, balance bush 26) having a sliding surface 34 on either the fixed side or the rotating side of the centrifugal pump 10 (10A) are fixed as separate bodies to the inner casing 12 (fixed side) or the main shaft 14 (rotating side). In contrast, in the present embodiment, the sliding parts 60 (60a, 60b, 60c) having the sliding surface 34 are part of the fixed side or the rotating side of the centrifugal pump 10 (10B). In the embodiment shown in FIG. 10, an example is shown in which the sliding parts 60 (60a, 60b, 60c) having the sliding surface 34 are part of the inner casing 12 (fixed side) of the centrifugal pump 10 (10B).

[0047] As shown in FIG. 10, a centrifugal pump 10 (10B) according to one embodiment of the present invention has a sliding portion 60 (60a, 60b, 60c) formed on either the fixed side or the rotating side of the centrifugal pump 10 (10B). In the embodiment shown in FIG. 10, a portion of the inner circumferential surface 12a of the inner casing 12 facing the shroud end portion 16a of the impeller 16 is the sliding portion 60a. Also, a portion of the inner circumferential surface 12a of the inner casing 12 facing the sleeve portion 16C of the impeller 16 is the sliding portion 60b. Also, a portion of the inner circumferential surface 12a of the inner casing 12 facing the balance sleeve 28 is the sliding portion 60c.

[0048] As shown in Figs. 2A to 2D, 3, 4A to 4B, the sliding portion 60 (60a, 60b, 60c) includes an opposing surface 30 disposed opposite to the other side component supported on either the fixed side or the rotating side of the centrifugal pump 10 (10B), a sliding surface 34 formed on at least a part of the opposing surface 30 and configured to slide against the other side component, and a surface treatment layer 36 formed by subjecting the sliding surface 34 to a surface treatment. At the end of the sliding surface 34, a base material exposed portion 40a is formed where the base material 40 not subjected to the surface treatment is exposed. With this configuration, it is possible to obtain the same effects as those of the embodiment shown in Figs. 1, 2A to 2D, 3, 4A to 4B.

[0049] Moreover, the centrifugal pump 10 (10B) according to one embodiment of the present invention has a sliding portion 60 (60a, 60b, 60c) formed on either the fixed side or the rotating side of the centrifugal pump 10 (10B), as shown in FIG. As shown in Figs. 2A to 2D, 3, and 5A to 5B, the sliding portion 60 (60a, 60b, 60c) includes an opposing surface 30 arranged to face the other side component supported on either the fixed side or the rotating side of the centrifugal pump 10 (10B), a sliding surface 34 formed on at least a part of the opposing surface 30 and configured to slide against the other side component, and a surface treatment layer 36 formed by performing a surface treatment over the entire sliding surface 34. The sliding surface 34 includes an end portion 34a formed by performing a chamfering process. With this configuration, it is possible to obtain the same effects as those of the embodiment shown in Figs. 1, 2A to 2D, 3, and 5A to 5B.

[0050] <First manufacturing method> FIG. 6 is a flow chart showing a method for producing a sliding component for a rotating machine according to one embodiment, and FIG. 7 is a schematic diagram showing the same in the order of the production steps.

[0051] As shown in Figs. 6 and 7 , a manufacturing method for a sliding part for a rotating machine according to one embodiment includes a preparation step (S10) of preparing a pre-machined sliding part 70, a groove processing step (S12) of processing grooves 72 on one side of the pre-machined sliding part 70, a surface treatment step (S14) of performing a surface treatment on a predetermined region of the one side 70a including the bottom surface 72a of the groove 72 of the pre-machined sliding part 70, and a cutting step (S16) of cutting the one side 70a of the pre-machined sliding part 70 to form at least one convex portion 76, in which the surface treatment layer 36 formed on the bottom surface 72a of the groove 72 is located in a central portion 76a2 excluding an end portion 76a1 of the convex surface 76a of the at least one convex portion 76.

[0052] In the preparation step (S10), a pre-machined sliding component 70 is prepared, which corresponds to at least one of the above-mentioned rotating machine sliding components, namely the impeller 16, the balance sleeve 28, the liner ring 24, the intermediate bushing 25, the balance bushing 26, and the ring-shaped member 27. These rotating machine sliding components have a facing surface 30 disposed opposite to the other side component, and a sliding surface 34 is formed on at least a part of the facing surface 30. One surface 70a of the pre-machined sliding component 70 (corresponding to the facing surface 30 of the rotating machine sliding component) is desirably a flat surface, but may be curved, and the shape thereof is not particularly limited.

[0053] In the groove processing step (S12), a groove 72 is processed in one surface 70a of the unmachined sliding component 70 prepared in the preparation step (S10). The width of the groove 72 processed in the groove processing step (S12) is smaller than the width of the protrusion 76 finally formed in this embodiment.

[0054] In the surface treatment step (S14), a surface treatment is applied to a predetermined region of the surface 70a including the bottom surface 72a of the groove 72 of the unmachined sliding component 70 machined in the groove machining step (S12). This surface treatment is performed by, for example, a method of forming a coating having corrosion resistance and wear resistance by thermal spraying, DCL coating, plating, or the like, or a method of imparting corrosion resistance and wear resistance by nitriding, or the like.

[0055] In the cutting step (S16), one surface 70a of the unmachined sliding component 70 that has been surface-treated in the surface treatment step (S14) is cut to form at least one convex portion 76. Then, one surface of the unmachined sliding component 70 is cut so that the surface treatment layer 36 formed on the bottom surface 72a of the groove 72 is located in a central portion 76a2 excluding an end portion 76a1 of the convex surface 76 of the at least one convex portion 76. As a result, the surface treatment layer 36 is formed in the central portion 76a2 of the convex surface 76a, and a base material exposed portion 40a where the base material 40 that has not been surface-treated is exposed is formed in the end portion 76a1 of the convex surface 76a. That is, the processed convex surface 76a corresponds to the sliding surface 34 of the sliding component for a rotating machine described above.

[0056] According to this configuration, the above-mentioned rotating machine sliding component (the impeller 16, the balance sleeve 28, the liner ring 24, the intermediate bush 25, the balance bush 26, and the ring-shaped member 27) can be manufactured. In this case, since the manufacturing method for the rotating machine sliding component according to one embodiment includes the above-mentioned surface treatment step (S14) and the cutting step (S16), the base material exposed portion 40a that has not been surface-treated can be formed at the end of the sliding surface 34 without applying masking or the like to the end of the sliding surface 34. In addition, after the groove 72 is machined on one surface 70a of the unmachined sliding component 70 and a predetermined region of the one surface 70a including the bottom surface 72a of the groove 72 is surface-treated, the one surface 70a of the unmachined sliding component 70 is cut to form at least one convex portion 76. Therefore, it is not necessary to prepare the unmachined sliding component 70 on which the convex portion 76 is formed in advance, and the rotating machine sliding component can be easily manufactured.

[0057] In one embodiment, in the groove processing step (S12), a spiral groove 72 is processed on one surface 70a of the unmachined sliding component 70 prepared in the preparation step (S10). In addition, in the cutting step (S16), a spiral convex portion 76 is formed by cutting out a portion between the spiral grooves 72 formed in the groove processing step (S14) in a spiral shape. According to this configuration, it is possible to easily manufacture a sliding component for a rotary machine having an opposing surface 30 including a thread groove region 42 in which a spirally extending thread groove 44 and a thread 46 are formed.

[0058] In one embodiment, the surface treatment in the surface treatment step (S14) is a nitriding treatment. According to such a configuration, unlike the case where a new coating layer is formed on the surface of the base material 70 forming the sliding surface, such as by thermal spraying, DCL coating, plating, etc., it is possible to form the surface treatment layer 36 inside the base material 70, which is not easily peeled off. Therefore, peeling of the surface treatment layer 36 can be further easily suppressed.

[0059] Moreover, the manufacturing method of the rotating machine sliding part according to one embodiment may further include a polishing step S18 for removing a hardened layer 78 having a hardness of 1000 Hv or more from the surface treatment layer 36 (surface treatment layer 36 formed by nitriding) of the sliding surface 34 formed in the cutting step (S16). By removing the hardened layer 78 in the polishing step S18, it becomes easier to prevent the rotating machine sliding part from becoming easily broken due to having a hardened layer 78 that is harder than necessary.

[0060] <Second manufacturing method> Fig. 8 is a flow chart showing a method for producing a sliding component for a rotating machine according to one embodiment. Fig. 9 is a schematic diagram showing a process preparation for the method for producing a sliding component for a rotating machine according to one embodiment.

[0061] One embodiment of a manufacturing method for a sliding part for a rotating machine is a manufacturing method for a sliding part for a rotating machine supported on either the fixed side or the rotating side of the rotating machine, and includes a preparation step (S20) of preparing an unprocessed sliding part 80 having a convex portion 86 formed on one surface 80a, a processing step (S22) of processing a central portion 862 of the convex portion 86 excluding an end portion 861 into a concave shape, a surface treatment step (S24) of performing a surface treatment on the convex surface 86a of the convex portion 86 processed into a concave shape, and a cutting step (S26) of cutting off the end portion 861 of the convex portion 86 processed into a concave shape.

[0062] In the preparation step (S20), an unmachined sliding component 80 is prepared, which corresponds to at least one of the above-mentioned rotating machine sliding components, i.e., the impeller 16, the balance sleeve 28, the liner ring 24, the intermediate bushing 25, the balance bushing 26, and the ring-shaped member 27. These rotating machine sliding components have an opposing surface 30 disposed opposite to the other side component, and a sliding surface 34 is formed on at least a part of the opposing surface 30. A convex portion 86 is formed on one surface 80a of the unmachined sliding component 80 (corresponding to the opposing surface 30 of the rotating machine sliding component).

[0063] In the machining step (S22), a central portion 862 of the protrusion 86, excluding both end portions 861 on both sides in the direction of the axis X, is machined into a concave shape to form the recess 82. The depth of the groove 82 machined in the machining step (S22) is smaller than the height of the protrusion 86.

[0064] In the surface treatment step (S24), a surface treatment is applied to the convex surface 86a in which the concave portions 82 are formed, to form the surface treatment layer 36. This surface treatment is performed by, for example, a method of forming a coating having corrosion resistance and wear resistance by thermal spraying, DCL coating, plating, or the like, or a method of imparting corrosion resistance and wear resistance by nitriding, or the like.

[0065] In the cutting step (S26), after the surface treatment step (S24), end portions 861 on both sides of the protrusion 86 in the direction of the axis X are cut off so as to be flush with the bottom surface of the recess 82. As a result, the surface treatment layer 36 is formed in the center portion 862 of the protrusion 86, and the base material exposed portion 40a is formed in the end portion 861 of the protrusion 86, where the base material 40 that has not been subjected to the surface treatment is exposed. In other words, the processed convex surface 86a corresponds to the sliding surface 34 of the sliding component for a rotating machine described above. Finally, finishing processing such as deburring and polishing is performed on the sliding surface 34 as necessary (finishing step S28).

[0066] According to this configuration, the above-mentioned rotating machine sliding component (the impeller 16, the balance sleeve 28, the liner ring 24, the intermediate bush 25, the balance bush 26, and the ring-shaped member 27) can be manufactured. In this case, since the manufacturing method for the rotating machine sliding component according to the embodiment includes the above-mentioned surface treatment step (S24) and the cutting step (S26), the base material exposed portion 40a that has not been subjected to surface treatment can be formed at the end of the sliding surface 34 without applying masking or the like to the end of the sliding surface 34. In addition, the protrusion 86 of the unmachined sliding component 80 having the protrusion 86 formed on one surface is processed into a concave shape, and the protrusion 86a is surface-treated, and then both end portions 861 of the protrusion 86 are cut off, so that the rotating machine sliding component can be manufactured with a small amount of the base material 40 to be cut off.

[0067] In one embodiment, the surface treatment in the surface treatment step (S24) is a nitriding treatment. According to such a configuration, unlike the case where a new coating layer is formed on the surface of the base material 70 forming the sliding surface 34, such as by thermal spraying, DCL coating, plating, etc., it is possible to form the surface treatment layer 36 inside the base material 70, which is not easily peeled off. Therefore, peeling of the surface treatment layer 36 can be further easily suppressed.

[0068] When nitriding is performed as the surface treatment, an anti-nitriding treatment is performed as necessary. In the anti-nitriding step (S23), the ends 861 on both sides of the protrusions 86 and the bottom surfaces of the grooves 82 are masked with masking tape 90, and an anti-nitriding agent 92 is applied to the other parts (particularly the side surfaces near the ends 861). This makes it possible to prevent the nitriding layer 36 from diffusing and being formed up to the ends 861 of the protrusions 86 in the subsequent surface treatment step (S24).

[0069] <Summary> The contents described in each of the above embodiments can be understood, for example, as follows.

[0070] (1) A sliding component for a rotating machine according to at least one embodiment of the present invention comprises: A sliding component for a rotating machine that is supported on either a fixed side or a rotating side of the rotating machine, An opposing surface 30 that is arranged to face the other side component supported on the other of the fixed side or the rotating side of the rotary machine; A sliding surface 34 formed on at least a part of the opposing surface 30 and configured to slide against the other side component; and a surface treatment layer 36 formed by subjecting the sliding surface 34 to a surface treatment, An end portion 34a of the sliding surface 34 is formed with a base material exposed portion 40a where the base material 40 that has not been subjected to the surface treatment is exposed.

[0071] According to the above configuration (1), the sliding surface 34 of the sliding component for a rotating machine has a surface treatment layer 36 formed by surface treatment, and the end portion 34a is formed with a base material exposed portion 40a where the base material 40 not subjected to surface treatment is exposed. In this way, by forming the base material exposed portion 40a where the surface treatment layer 36 is easily peeled off at the end portion, it is possible to prevent the spread of the peeled portion caused by the peeling of the surface treatment layer 36 at the end portion 34a, and thereby to improve the life of the surface treatment layer 36. Therefore, it is possible to improve the durability of a rotating machine equipped with the sliding component for a rotating machine.

[0072] (2) In some embodiments, in the configuration of (1) above, The base material exposed portion 40a is formed of a cut surface formed by cutting a part of the base material 40.

[0073] According to the above configuration (2), the base material exposed portion 40a is made of a cut surface formed by cutting a part of the base material 40, so that it is easy to form the base material exposed portion 40a. Even in the case of a surface treatment in which the surface treatment layer 36 is formed from the sliding surface 34 to a predetermined depth, the base material exposed portion 40a can be easily formed by cutting the formed surface treatment layer 36.

[0074] (3) In at least one embodiment of the present invention, a sliding part for a rotating machine comprises: A sliding component for a rotating machine that is supported on either a fixed side or a rotating side of the rotating machine, An opposing surface 30 that is arranged to face the other side component supported on the other of the fixed side or the rotating side of the rotary machine; A sliding surface 34 formed on at least a part of the opposing surface 30 and configured to slide against the other side component; and a surface treatment layer 36 formed by performing a surface treatment on the entire sliding surface 34. The sliding surface 34 includes an end 34a formed by chamfering.

[0075] According to the above configuration (3), the sliding component for a rotating machine includes a surface treatment layer 36 formed by performing a surface treatment over the entire sliding surface, and an end portion 34a formed by performing a chamfering process. In this manner, by performing a chamfering process on the end portion 34a where the surface treatment layer 36 is likely to peel off, it is possible to prevent the spread of the peeled portion caused by the peeling of the surface treatment layer 36 at the end portion, thereby improving the life of the surface treatment layer 36. Therefore, it is possible to improve the durability of a rotating machine including the sliding component for a rotating machine.

[0076] (4) In some embodiments, in the configuration of (3) above, the end 34a of the sliding surface 34 has a rounded chamfered shape.

[0077] According to the above configuration (4), the end 34a of the sliding surface 34 has a rounded chamfered shape, so that peeling of the surface treatment layer 36 at the end 34a can be further suppressed.

[0078] (5) In some embodiments, in the configurations (3) to (4) above, The chamfering dimension of the end portion 34a is C, When the width dimension of the sliding surface 34 is D, C / D is 0.100 or more and 0.250 or less.

[0079] According to the above configuration (5), since C / D is 0.100 or more, the end 34a that has been subjected to chamfering and has a predetermined size or more can be secured. Therefore, peeling of the surface treatment layer 36 at the end 34a of the sliding surface 34 can be easily suppressed. In addition, since C / D is 0.250 or less, the size of the sliding surface 34 that has not been subjected to chamfering can be secured. Therefore, the sealing performance of the sliding surface 34 can be easily maintained.

[0080] (6) In some embodiments, in the configurations (1) to (5) above, The surface treatment is a nitriding treatment.

[0081] According to the above configuration (6), the surface treatment is a nitriding treatment. Therefore, unlike the case where a new coating layer is formed on the surface of the base material 40 forming the sliding surface 34, such as by thermal spraying, DCL coating, plating, etc., a surface treatment layer 36 that is difficult to peel off can be formed not only on the surface of the base material 40 but also inside the base material 40. Therefore, peeling of the surface treatment layer 36 can be further easily suppressed.

[0082] (7) In some embodiments, in the configurations (1) to (6) above, A rotating machine including the above-mentioned sliding component for a rotating machine.

[0083] According to the above configuration (7), since the rotating machine sliding component having an improved life span is provided, the durability of the rotating machine is improved and the operating time can be extended.

[0084] (8) A rotary machine according to at least one embodiment of the present invention includes: A rotating machine having a sliding part formed on either a fixed side or a rotating side of the rotating machine, The sliding portion is An opposing surface 30 that is arranged to face the other side component supported on the other of the fixed side or the rotating side of the rotary machine; A sliding surface 34 formed on at least a part of the opposing surface 30 and configured to slide against the other side component; and a surface treatment layer 36 formed by subjecting the sliding surface 34 to a surface treatment, An end portion 34a of the sliding surface 34 is formed with a base material exposed portion 40a where the base material 40 that has not been subjected to the surface treatment is exposed.

[0085] According to the above configuration (8), the surface treatment layer 36 is formed by performing a surface treatment on the sliding surface, and the end 34a of the sliding surface 34 has a base material exposed portion 40a where the base material 40 not subjected to the surface treatment is exposed. In this way, by forming the base material exposed portion 40a where the surface treatment layer 36 is easily peeled off at the end 34a where the surface treatment layer 36 is easily peeled off, it is possible to prevent the spread of the peeled part caused by the peeling of the surface treatment layer 36 at the end 34a, and thereby to improve the life of the surface treatment layer 36. Therefore, the durability of the rotating machine can be improved.

[0086] (9) A rotary machine according to at least one embodiment of the present invention includes: A rotating machine having a sliding part formed on either a fixed side or a rotating side of the rotating machine, The sliding portion is An opposing surface 30 that is arranged to face the other side component supported on the other of the fixed side or the rotating side of the rotary machine; A sliding surface 34 formed on at least a part of the opposing surface 30 and configured to slide against the other side component; and a surface treatment layer 36 formed by performing a surface treatment on the entire sliding surface 34. The sliding surface 34 includes an end 34a formed by chamfering.

[0087] The above configuration (9) includes the surface treatment layer 36 formed by performing a surface treatment on the entire sliding surface 34, and the end portion 34a formed by performing a chamfering process. In this way, by performing a chamfering process on the end portion where the surface treatment layer 36 is likely to peel off, it is possible to prevent the spread of the peeled portion caused by the peeling of the surface treatment layer 36 at the end portion 34a, thereby improving the life of the surface treatment layer 36. Therefore, it is possible to improve the durability of the rotating machine.

[0088] (10) A method for producing a sliding part for a rotary machine according to at least one embodiment of the present invention includes the steps of: A method for manufacturing a sliding component for a rotating machine that is supported on either a fixed side or a rotating side of the rotating machine, comprising the steps of: a groove processing step (S12) of processing a groove 72 on one surface of the unprocessed sliding component 70; a surface treatment step (S14) of performing a surface treatment on a predetermined area of ​​the one surface including the bottom surface 72a of the groove 72 of the unmachined sliding component 70; a cutting step (S16) of cutting the one surface of the unmachined sliding component 70 to form at least one convex portion 76, in which the one surface of the unmachined sliding component 70 is cut so that the surface treatment layer 36 formed on the bottom surface 72a of the groove 72 is located in a central portion 76a2 excluding an end portion 76a1 of a convex surface 76a of the at least one convex portion 76; Equipped with.

[0089] According to the configuration of (10) above, the sliding component for a rotating machine described in (1) above can be manufactured. In this case, since the manufacturing method for a sliding component for a rotating machine according to one embodiment includes the above-mentioned surface treatment step (S14) and cutting step (S16), the end 34a of the sliding surface 34 can be formed with the base material exposed portion 40a that has not been subjected to surface treatment without masking the end 34a. In addition, the groove 72 is machined on one side of the unmachined sliding component 70, a predetermined region of the one side including the bottom surface 72a of the groove 72 is surface treated, and then the one side of the unmachined sliding component 70 is cut to form at least one convex portion 76. Therefore, it is not necessary to prepare the unmachined sliding component 70 on which the convex portion 76 is formed in advance, and the sliding component for a rotating machine can be easily manufactured.

[0090] (11) In some embodiments, in the configuration of (10), The surface treatment step (S14) is a nitriding treatment.

[0091] According to the above configuration (11), unlike the case where a new coating layer is formed on the surface of the base material 40 forming the sliding surface 34, such as by thermal spraying, DCL coating, plating, etc., it is possible to form the surface treatment layer 36 inside the base material 40, which is not easily peeled off. Therefore, peeling of the surface treatment layer 36 can be further easily suppressed.

[0092] (12) In some embodiments, in the configuration described in (11) above, The method further includes a polishing step S18 for removing a hardened layer 78 having a hardness of 1000 Hv or more from the surface treatment layer 36 after the cutting step (S16).

[0093] The above configuration (12) includes a polishing step (S18) for removing the hardened layer 78 having a hardness of 1000 Hv or more from the surface treatment layer 36. This makes it easier to prevent the rotating machine sliding component from becoming easily broken due to the hardened layer 78 being harder than necessary.

[0094] (13) A method for producing a sliding part for a rotary machine according to at least one embodiment of the present invention includes the steps of: A method for manufacturing a sliding component for a rotating machine that is supported on either a fixed side or a rotating side of the rotating machine, comprising the steps of: A processing step (S22) of processing a central portion 862 of the protruding portion 86, excluding an end portion 861, into a concave shape on the unprocessed sliding component 80 having a protruding portion 86 formed on one surface thereof; a surface treatment step (S24) of performing a surface treatment on the convex surface 86a of the convex portion 86 that has been processed into the concave shape; a cutting step (S26) of cutting off the end 861 of the protrusion 86 processed into the concave shape; Equipped with.

[0095] According to the configuration of (13) above, the sliding component for a rotating machine described in (1) above can be manufactured. In this case, since the manufacturing method for a sliding component for a rotating machine according to one embodiment includes the above-mentioned surface treatment step (S24) and the cutting step, the end 34a of the sliding surface 34 can be formed with the base material exposed portion 40a that has not been subjected to surface treatment even without applying masking or the like to the end 34a of the sliding surface 34. In addition, the protrusion 76 of the unmachined sliding component 80 having the protrusion 76 formed on one surface is processed into a concave shape, and the convex surface 76a is surface-treated, and then both end portions 76a1 of the convex surface 76a are cut off, so that the sliding component for a rotating machine can be manufactured with a small amount of the base material 40 cut off.

[0096] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and also includes modifications to the above-described embodiments and appropriate combinations of these modifications.

[0097] In this specification, expressions expressing relative or absolute configuration, such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial," do not only strictly represent such a configuration, but also represent 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 indicating that things are in an equal state, such as "identical," "equal," and "homogeneous," 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. Furthermore, in this specification, expressions describing shapes such as a rectangular shape or a cylindrical shape do not only refer to shapes such as a rectangular shape or a cylindrical shape in the strict geometric sense, but also refer to shapes that include uneven portions, chamfered portions, etc., to the extent that the same effect is obtained. In addition, in this specification, the expressions "comprise," "include," or "have" a certain element are not exclusive expressions that exclude the presence of other elements. [Explanation of symbols]

[0098] 10(10A, 10B) Centrifugal pump 12 Inner casing 12a Inner surface 14 Spindle 16 Impeller 16a Shroud end 16b Outer surface 16c Outer surface 16A Shroud section 16B Hub section 16C Sleeve section 18 wings 24 Linear Ring 24a Opposite side 25 Intermediate bush 26 Balance bush 27 Ring-shaped member 28 Balance Sleeve 28a Outer surface 30 Opposite Surface 34 Sliding surface 34a end 34a1 Square groove end 34a2 Chamfered end 36 Surface treatment layer 40 Base material 40a Base metal exposed part (end) 42 Thread groove area 44 Thread groove 46 threads 70 Unprocessed sliding parts 72 Groove 72a (groove) bottom 76 Convex 76a Convex 76a1 (Convex) End 76a2 (convex) central part 78 Hardened layer 80 Unprocessed sliding parts 82 Recess 86 Convex 86a Convex 861 End 862 Central part 90 Masking Tape 92 Nitriding inhibitor

Claims

1. A sliding component for a rotating machine that is supported on either a fixed side or a rotating side of the rotating machine, an opposing surface that is disposed opposite to a second-side component that is supported on the other of the fixed side or the rotating side of the rotary machine; a sliding surface formed on at least a part of the opposing surface and configured to slide against the other-side component; a surface treatment layer formed by subjecting the sliding surface to a surface treatment, The opposing surface includes a threaded region having a screw groove and a screw thread formed therein; the sliding surface includes a top portion of the thread which is a plane formed along an axial direction of the rotating machine, A sliding component for a rotating machine, wherein a base material exposed portion is formed at both ends of the crest of the screw thread, where the base material not subjected to the surface treatment is exposed.

2. 2. The sliding component for a rotating machine according to claim 1, wherein the base material exposed portion is a cut surface formed by cutting a part of the base material.

3. A sliding component for a rotating machine that is supported on either a fixed side or a rotating side of the rotating machine, an opposing surface that is disposed opposite to a second-side component that is supported on the other of the fixed side or the rotating side of the rotary machine; a sliding surface formed on at least a part of the opposing surface and configured to slide against the other-side component; A surface treatment layer formed by performing a surface treatment on the entire sliding surface, The opposing surface includes a threaded region having a screw groove and a screw thread formed therein; the sliding surface includes a top portion of the thread which is a plane formed along an axial direction of the rotating machine, The top of the thread is chamfered to form both ends of the thread.

4. 4. The sliding component for a rotating machine according to claim 3, wherein said both ends of the crest of said thread are rounded and chamfered.

5. The chamfering dimension of both ends is C, When the width dimension of the top of the thread is D, 5. The sliding part for a rotating machine according to claim 3, wherein C / D is 0.100 or more and 0.250 or less.

6. 6. The sliding part for a rotating machine according to claim 1, wherein the surface treatment is a nitriding treatment.

7. A rotating machine comprising the sliding component for a rotating machine according to any one of claims 1 to 6.

8. A rotating machine having a sliding part formed on either a fixed side or a rotating side of the rotating machine, The sliding portion is an opposing surface that is disposed opposite to a second-side component that is supported on the other of the fixed side or the rotating side of the rotary machine; a sliding surface formed on at least a part of the opposing surface and configured to slide against the other-side component; a surface treatment layer formed by subjecting the sliding surface to a surface treatment, The opposing surface includes a threaded region having a screw groove and a screw thread formed therein; the sliding surface includes a top portion of the thread which is a plane formed along an axial direction of the rotating machine, A rotating machine, wherein a base material exposed portion is formed at both ends of the crest of the screw thread, where the base material that has not been subjected to the surface treatment is exposed.

9. A rotating machine having a sliding part formed on either a fixed side or a rotating side of the rotating machine, The sliding portion is an opposing surface that is disposed opposite to a second-side component that is supported on the other of the fixed side or the rotating side of the rotary machine; a sliding surface formed on at least a part of the opposing surface and configured to slide against the other-side component; A surface treatment layer formed by performing a surface treatment on the entire sliding surface, The opposing surface includes a threaded region having a screw groove and a screw thread formed therein; the sliding surface includes a top portion of the thread which is a plane formed along an axial direction of the rotating machine, A rotating machine including both ends, the top of the screw thread being formed by chamfering.

10. A method for manufacturing a sliding component for a rotating machine that is supported on either a fixed side or a rotating side of the rotating machine, comprising the steps of: a groove processing step of processing a groove on one surface of the unprocessed sliding component; a surface treatment process for performing a surface treatment on a predetermined region of the one surface including a bottom surface of the groove of the unmachined sliding component; a cutting step of cutting the one surface of the unmachined sliding component to form at least one convex portion, the cutting step being such that the surface treatment layer formed on the bottom surface of the groove is located in a central portion of a convex surface of the at least one convex portion excluding an end portion; A method for manufacturing a sliding part for a rotating machine comprising the steps of:

11. The method for producing a sliding part for a rotating machine according to claim 10, wherein the surface treatment is a nitriding treatment.

12. The method for producing a sliding part for a rotating machine according to claim 11, further comprising, after the cutting step, a polishing step of removing a hardened layer having a hardness of 1000 Hv or more from the surface treatment layer.

13. A method for manufacturing a sliding component for a rotating machine that is supported on either a fixed side or a rotating side of the rotating machine, comprising the steps of: a processing step of processing a central portion of a pre-processed sliding component having a convex portion formed on one surface thereof into a concave portion except for an end portion of the convex portion; a surface treatment step of performing a surface treatment on the convex surface of the convex portion processed into the concave shape; a cutting step of cutting off the end of the protrusion processed into the concave shape; A method for manufacturing a sliding part for a rotating machine comprising the steps of:

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