sliding member

Abstract

Provided is a sliding member capable of improving the lubricity of sliding surfaces with respect to each other. A sliding member (10) configured to slide with respect to another sliding member (20) in a rotating machine, wherein a plurality of protrusions (30) are provided on a sliding surface (11) of the sliding member (10), and a groove (14) is formed that connects between adjacent protrusions (30) and is continuous from a sealing side (S1) to a leakage side (S2).

Description

Technical Field

[0001] This invention relates to sliding components that rotate relative to each other, such as sliding components used in shaft sealing devices for sealing rotating shafts of rotating machinery in the fields of automobiles, general industrial machinery or other sealing applications, or sliding components used in bearings of machinery in the fields of automobiles, general industrial machinery or other bearing applications. Background Technology

[0002] As a shaft sealing device to prevent leakage of the sealed fluid, a mechanical seal, for example, has a pair of annular sliding parts that rotate relative to each other and whose sliding surfaces slide against each other. In recent years, for environmental countermeasures and other reasons, it has been desirable to reduce the energy of damage caused by sliding in such mechanical seals.

[0003] For example, the mechanical seal shown in Patent Document 1 is configured as a pair of annular sliding components capable of relative rotation. A sealed fluid exists in the outer space, and a liquid with a higher pressure than the sealed fluid exists in the inner space. In one sliding component, multiple grooves are circumferentially formed by cutting the sliding surface. These grooves communicate with the inner space containing the high-pressure liquid, and their outer diameter ends are closed. Furthermore, when the pair of sliding components rotate at high speed relative to each other, the high-pressure liquid present in the inner space is introduced into the grooves, generating positive pressure at and near the outer diameter ends, causing the sliding surfaces of the pair of sliding components to slightly separate, thereby forming a liquid film and achieving low friction.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 64-46068 (Page 3, Figure 2) Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] In a sliding component like that in Patent Document 1, dynamic pressure is generated on the sliding surface of a sliding component during high-speed rotation, causing the sliding surfaces to slightly separate and form a liquid film, thereby improving the lubrication between the sliding surfaces. However, since the land surrounding the groove is a flat surface, when stationary, the land is in contact with the sliding surfaces of other sliding components. Therefore, at the start of relative rotation and during low-speed rotation, there is a possibility of localized poor lubrication between the sliding surfaces, leading to increased torque, wear of the sliding surfaces, etc.

[0009] This invention was made in view of such a problem, and its purpose is to provide a sliding component that can improve the lubricity of the sliding surfaces.

[0010] Methods for solving problems

[0011] To solve the above-mentioned problems, the sliding component of the present invention is disposed in a part of the rotating machinery that rotates relative to it and slides relative to other sliding components. The sliding surface of the sliding component is provided with a plurality of protrusions and a groove is formed that is connected to the adjacent protrusions and is continuous from the sealing side to the leakage side.

[0012] Therefore, fluid can be introduced into the sliding surface as a whole from the sealing side to the leakage side through the grooves formed between the multiple protrusions constituting the sliding surface. As a result, the lubrication between the sliding surfaces can be improved.

[0013] Alternatively, at least two regions with different densities of the protrusions may be formed on the sliding surface.

[0014] Therefore, the density of the protrusions can be adjusted according to the required function of each area of ​​the sliding surface. This allows for control over lubrication and sealing performance.

[0015] Alternatively, the sliding surface may have a dynamic pressure generating recess, and the groove may be formed on the dynamic pressure generating recess.

[0016] Therefore, the fluid introduced into the dynamic pressure generating recess is guided through the groove facing the dynamic pressure generating recess to the land surrounding the dynamic pressure generating recess. As a result, the lubrication between the sliding surfaces can be improved.

[0017] Alternatively, the density of the protrusions in the region facing the dynamic pressure generating recess may be configured to be higher than the density of the protrusions in the region adjacent to that region.

[0018] Therefore, during high-speed rotation, the amount of fluid introduced into the dynamic pressure generating recess that is diverted to the land through the groove formed by the protrusions in the region facing the dynamic pressure generating recess can be reduced. Thus, dynamic pressure can be easily generated through the dynamic pressure generating recess.

[0019] Alternatively, the density of the protrusions in the region of the space facing the leakage side can be configured to be higher than the density of the protrusions in the region adjacent to that region.

[0020] This reduces the amount of fluid that is introduced into the sliding surface through the groove and leaks out through the groove formed by the protrusion in the area facing the leakage side. Therefore, it improves the sealing performance between the sliding surfaces.

[0021] Alternatively, the multiple protrusions may be arranged in a regular pattern, with each protrusion being a point shape.

[0022] Therefore, the pattern of the groove can be changed according to the density of the protrusions.

[0023] Alternatively, the protrusion may be fixed to the substrate.

[0024] Therefore, it is easy to form a groove pattern on the sliding surface. Attached Figure Description

[0025] Figure 1 This is a cross-sectional view showing an example of the mechanical seal of Embodiment 1 of the present invention.

[0026] Figure 2 This is a diagram showing the sliding surface of the stationary sealing ring of Embodiment 1 as viewed from the axial direction. For ease of explanation, only the annular protrusion of the stationary sealing ring with the sliding surface is shown; the base is omitted.

[0027] Figure 3 This is a schematic diagram viewed from the axial direction showing a pattern of a plurality of protrusions formed on the sliding surface of the stationary sealing ring of Embodiment 1 of the present invention and the grooves formed between the protrusions.

[0028] Figure 4 This is an enlarged schematic diagram, viewed radially, showing a pattern of multiple protrusions formed on the sliding surface of the stationary sealing ring of Embodiment 1 and the grooves formed between the protrusions.

[0029] Figure 5 This is a schematic diagram viewed from the axial direction showing a pattern of multiple protrusions formed on the sliding surface of the stationary sealing ring of Embodiment 2 of the present invention and the grooves formed between the protrusions.

[0030] Figure 6 (a) and (b) are enlarged schematic diagrams viewed radially, showing the pattern of a plurality of protrusions formed on the sliding surface of the stationary sealing ring of Embodiment 2 and the grooves formed between the protrusions.

[0031] Figure 7 (a) and (b) are schematic diagrams of the pattern of multiple protrusions and grooves formed between the protrusions in the modified example, viewed from the axial direction. Detailed Implementation

[0032] Hereinafter, the method of implementing the sliding component of the present invention will be described based on embodiments.

[0033] Example 1

[0034] Reference Figures 1 to 4 The sliding component of Embodiment 1 will be described. In this embodiment, the sliding component is described as a mechanical seal. Furthermore, the case where the sealed fluid exists within the inner space of the mechanical seal and the atmosphere exists in the outer space, is described with the inner diameter side of the sliding component constituting the mechanical seal as the sealed fluid side (high-pressure side) and the outer diameter side as the leakage side (low-pressure side). Additionally, for ease of explanation, markings such as the land area formed on the sliding surface are sometimes included in the accompanying drawings.

[0035] Figure 1 The mechanical seal shown is a general-purpose industrial mechanical seal, which seals the fluid F that is to be leaked from the space on the inner diameter side of the sliding surface (i.e., the sealing side, inner space S1) to the space on the outer diameter side of the sliding surface (i.e., the leakage side, outer space S2). The outer space S2 is open to the atmosphere A. Furthermore, in this embodiment, the sealed fluid F is illustrated as a high-pressure liquid, and the atmosphere A is a gas with a lower pressure than the sealed fluid F.

[0036] The mechanical seal mainly consists of a stationary annular sealing ring 10, which serves as a sliding component, and a rotary annular sealing ring 20, which serves as another sliding component. The rotary sealing ring 20 is mounted on the rotating shaft 1 in a manner that allows it to rotate together with the rotating shaft 1 via a sleeve 2. The stationary sealing ring 10 is mounted on a sealing cover 5 in a non-rotating state and is axially movable; this sealing cover 5 is fixed to the housing 4 of the installed equipment. Furthermore, the mechanical seal applies axial force to the stationary sealing ring 10 using an elastic member 6, causing the sliding surface 11 of the stationary sealing ring 10 and the sliding surface 21 of the rotary sealing ring 20 to slide in close contact. Additionally, the sliding surface 21 of the rotary sealing ring 20 is a flat surface without grooves or other recesses.

[0037] In this embodiment, the stationary sealing ring 10 and the rotating sealing ring 20 are formed of SiC (silicon carbide). Furthermore, the stationary sealing ring 10 and the rotating sealing ring 20 are not limited to being made of the same raw material; they can also be made of different raw materials.

[0038] like Figure 1 As shown, the stationary sealing ring 10 has an annular protrusion 10b. The annular protrusion 10b protrudes axially from the annular base 10a toward the rotating sealing ring 20. In addition, a sliding surface 11 of the stationary sealing ring 10 is formed at the front end of the annular protrusion 10b.

[0039] like Figures 2-4 As shown, a plurality of protrusions 30 are provided at the front end of the annular protrusion 10b of the stationary sealing ring 10. The sliding surface 11 of the stationary sealing ring 10 is composed of a land portion 12 and a plurality of dynamic pressure generating recesses 13. The land portion 12 is formed by a plurality of fine protrusions 30 provided at the front end of the annular protrusion 10b. The plurality of dynamic pressure generating recesses 13 are surrounded by the land portion 12 and are evenly arranged circumferentially. That is, the substantial sliding surface 11 of the stationary sealing ring 10 that abuts against the sliding surface 21 of the rotating sealing ring 20 is composed of the front ends of the plurality of protrusions 30 forming the land portion 12. In addition, for ease of explanation, in Figure 2 In the middle, the land section 12 is schematically shown with dots.

[0040] The land portion 12 has a first land portion 12a and an annular second land portion 12b. The first land portion 12a is formed between adjacent dynamic pressure generating recesses 13 in the circumferential direction. The second land portion 12b is formed on the outer diameter side of the dynamic pressure generating recesses 13.

[0041] The dynamic pressure generating recess 13 is formed in a region where no protrusion 30 is provided at the front end of the annular protrusion 10b. That is, the bottom surface of the dynamic pressure generating recess 13 is formed by the flat surface 10c of the annular protrusion 10b where no protrusion 30 is provided, and the side wall portion erected from the bottom surface is formed by a plurality of protrusions 30 disposed at the boundary between the dynamic pressure generating recess 13 and the first land portion 12a and the second land portion 12b.

[0042] Furthermore, in this embodiment, the dynamic pressure generating recess 13 is formed as an inclined groove, the inner diameter end of which communicates with the inner space S1 where the sealed fluid F exists, and the outer diameter end of which is closed. Additionally, as... Figure 2 As shown, the dynamic pressure generating recess 13 generates dynamic pressure by the rotating sealing ring 20 sliding relative to the stationary sealing ring 10 in a counterclockwise direction as indicated by the solid arrow.

[0043] Next, protrusion 30 will be described in detail. For example... Figure 3 and Figure 4 As shown, the protrusion 30 is fixed by firing after applying ink containing ceramic powder, which is granulated by inkjet printing, to the flat surface 10c of the annular protrusion 10b, which serves as a substrate. Furthermore, firing the ink containing ceramic powder improves the adhesion of the protrusion 30 to the substrate.

[0044] Furthermore, from the viewpoint of the adhesion of the protrusion 30 to the substrate, the ceramic powder contained in the ink is preferably the same material as the substrate, that is, SiC powder in this embodiment. Alternatively, the ceramic powder contained in the ink may be other ceramic powders different from the substrate.

[0045] like Figure 3 As shown, when the sliding surface 11 is viewed axially, the plurality of protrusions 30 forming the land portion 12 are formed in a generally equal and regular manner. Furthermore, each protrusion 30 is dot-shaped. That is, the protrusions can be arranged in a generally equal manner along the circumferential direction or in a generally equal manner along the radial direction, or adjacent columns of protrusions can be arranged at the same phase relative to columns of protrusions arranged in each direction, or they can be arranged with phases offset. For example, relative to a column of protrusions arranged circumferentially, each protrusion in a radially adjacent column of protrusions arranged circumferentially can be arranged at the same phase in the radial direction, or they can be arranged at different phases in the radial direction. That is, regularity means that as long as a column of protrusions is arranged in a generally equal manner in any direction, it is sufficient. Furthermore, as... Figure 4As shown, when the sliding surface 11 is viewed radially, the protrusion 30 has a convex curved shape. That is, the protrusion 30 is formed into a dome shape. In addition, the front ends of the plurality of protrusions 30 forming the land portion 12 are arranged in the same plane, and as described above, they constitute the substantial sliding surface 11 of the stationary sealing ring 10.

[0046] Furthermore, the external dimensions of the protrusion 30 (more specifically, the external dimensions of the base of the protrusion 30 fixed to the flat surface 10c of the annular protrusion 10b) can be freely configured. Additionally, from the viewpoint of using surface tension to retain the sealed fluid F in the groove 14 (described later), a diameter of 0.3 μm or more and 2 mm or less is preferred.

[0047] Furthermore, the plurality of protrusions 30 forming the land portion 12 are separated at equal intervals and arranged in a staggered and regular pattern. A mesh-like groove 14 is formed that connects to adjacent protrusions 30 (i.e., the space between two adjacent protrusions 30 is connected to the space between two other adjacent protrusions 30 in the direction of the sliding surface 11) and continues from the sealing side to the leakage side. More specifically, as... Figure 4 As shown in the enlarged portion, the bottom surface of the groove 14 is formed by a flat surface 10c of the annular protrusion 10b without the protrusion 30, and the side wall portion erected from this bottom surface is formed by a plurality of protrusions 30. Furthermore, when the rotary sealing ring 20 stops rotating, dynamic pressure is not generated by the dynamic pressure generating recess 13, and the stationary sealing ring 10 is subjected to axial force by the elastic member 6. Therefore, the front end of the protrusion 30 is in contact with the sliding surface 21 of the rotary sealing ring 20. Furthermore, a receiving space S3 capable of receiving the sealed fluid F is defined between the sliding surfaces 11 and 21 by the groove 14 and the sliding surface 21 of the rotary sealing ring 20. In addition, the receiving space S3 communicates with the inner space S1, the outer space S2, and the dynamic pressure generating recess 13.

[0048] Additionally, the separation dimension L1 of adjacent protrusions 30, and more specifically, the separation dimension L1 of the geometric centers of adjacent protrusions 30 (refer to...). Figure 4 The groove 14 can be freely configured, but from the viewpoint of using surface tension to retain the sealed fluid F, it is preferably 0.3 μm or more and 2 mm or less. Furthermore, the separation dimension L1 of adjacent protrusions 30 is configured, for example, to be much smaller than the width dimension L2 of the opening of the dynamic pressure generating recess 13 (see reference). Figure 4 (L1 < L2).

[0049] As explained above, a plurality of protrusions 30 constituting the land portion 12 are provided on the sliding surface 11 of the stationary sealing ring 10, and grooves 14 are formed that connect with adjacent protrusions 30 and are continuous from the sealing side to the leakage side. Therefore, the sealed fluid F can be introduced into the sliding surface 11 as a whole from the sealing side to the leakage side through the grooves 14 that connect with the plurality of protrusions 30 constituting the land portion 12, thus improving the lubricity of the sliding surfaces 11 and 21. Furthermore, the sealed fluid F introduced into the land portion 12 through the grooves 14 is held around the plurality of fine protrusions 30 constituting the grooves 14 due to surface tension. Therefore, the lubricity of the sliding surfaces 11 and 21 can be maintained at all times.

[0050] Specifically, when the rotary sealing ring 20 stops rotating, the sealed fluid F is held in the groove 14 due to surface tension. That is, the receiving space S3, defined by the groove 14 and the sliding surface 21 of the rotary sealing ring 20, is filled with the sealed fluid F. Therefore, at the start of relative rotation, the sliding surfaces 11 and 21 are supplied with the sealed fluid F, resulting in good lubrication and achieving low friction.

[0051] Furthermore, when the rotary sealing ring 20 rotates at high speed, dynamic pressure is generated through the recess 13, causing the sliding surfaces 11 and 21 to separate slightly from each other, thereby forming a liquid film from the sealed fluid F. In this way, lubrication can be further improved not only when the rotary sealing ring 20 rotates at high speed, but also when it rotates at low speed.

[0052] Furthermore, the groove 14 is formed facing the dynamic pressure generating recess 13, and the sealed fluid F introduced into the dynamic pressure generating recess 13 is introduced through the groove 14 facing the dynamic pressure generating recess 13 to the land portion 12 formed around the dynamic pressure generating recess 13, especially the first land portion 12a. Therefore, the lubrication between the sliding surfaces 11 and 21 can be improved.

[0053] Furthermore, since the protrusions 30 are formed in a generally equal and regular manner, and each protrusion 30 is dot-shaped, the pattern of the groove 14 can be changed by adjusting the arrangement density of the protrusions 30. For example, reducing the arrangement density of the protrusions 30 can form a groove with a pattern of large flow path cross-sectional area, or increasing the arrangement density of the protrusions 30 can form a groove with a pattern of small flow path cross-sectional area. This allows adjustment of the amount of sealed fluid F introduced into the land portion 12, thereby controlling lubrication and sealing performance.

[0054] Furthermore, the protrusion 30 is formed by fixing it to the surface of the substrate, namely the flat surface 10c of the annular protrusion 10b. Therefore, compared to forming a groove by cutting the surface of the substrate using a laser or the like, it is easier to form a pattern of the groove 14 on the sliding surface 11. In particular, in the case where the protrusion 30 is small and its shape is dome-shaped, as in this embodiment, the pattern of the groove 14 is very complex. Therefore, by fixing the protrusion 30 to the surface of the substrate using inkjet printing, the sliding part can be easily manufactured. Alternatively, as a method other than inkjet printing, the protrusion 30 can also be fixed by using a 3D printer to laminate it onto the surface of the substrate.

[0055] Furthermore, the protrusion 30 is formed by firing ink containing ceramic powder, thereby creating numerous pores on its surface. This allows the sealed fluid F to be retained within these pores as well. Consequently, the lubrication between the sliding surfaces 11 and 21 is improved.

[0056] Furthermore, the dynamic pressure generating recesses 13 are evenly distributed along the circumference of the sliding surface 11, enabling the balanced generation of dynamic pressure between the sliding surfaces 11 and 21. Therefore, the uniform formation of the liquid film further improves the lubricity between the sliding surfaces 11 and 21.

[0057] Furthermore, in this embodiment 1, the dynamic pressure generating recess 13 that generates positive pressure was described. However, when the dynamic pressure generating recess functions to generate negative pressure and discharge the sealed fluid F from between the sliding surfaces 11 and 21 into the inner space S1, the sealed fluid F is also retained in the groove 14 due to surface tension. Therefore, it is easy to maintain the lubrication state of the sliding surfaces 11 and 21.

[0058] Example 2

[0059] Reference Figure 5 and Figure 6 The sliding component of Embodiment 2 will be described. Furthermore, descriptions of structures identical to those in Embodiment 1 described above will be omitted.

[0060] like Figure 5 As shown, the stationary sealing ring 210, which is the sliding component of this embodiment 2, has multiple regions with grooves 14A to 14D of different patterns formed on the land portion 212 constituting the sliding surface 211.

[0061] Specifically, in the region extending approximately from the radial center of the first landmass 212a to the second landmass 212b, adjacent protrusions 30A are spaced apart from each other at equal intervals. The grooves 14A formed between these protrusions 30A have the same pattern as the grooves 14 formed between adjacent protrusions 30 in Embodiment 1 described above (see reference). Figure 4 (The magnified portion).

[0062] Furthermore, in the regions of the first landmass 212a and the second landmass 212b that meet the boundary of the dynamic pressure generating recess 13, portions of a plurality of protrusions 30B facing the dynamic pressure generating recess 13 overlap each other, forming a higher density arrangement than the arrangement density of protrusions 30A in adjacent first landmasses 212a and second landmasses 212b. Therefore, the grooves 14B formed between these protrusions 30B have a pattern with a flow path cross-sectional area smaller than that of the grooves 14A (see reference). Figure 6 (a)

[0063] Therefore, when the rotary sealing ring 20 rotates at high speed, the amount of sealed fluid F introduced into the dynamic pressure generating recess 13 and introduced into the land portion 212 formed around the dynamic pressure generating recess 13 through the groove 14B facing the dynamic pressure generating recess 13 can be reduced. Thus, when the rotary sealing ring 20 rotates at high speed, it is easy to increase the pressure at and near the outer diameter end of the dynamic pressure generating recess 13, and dynamic pressure is easily generated. Furthermore, in this embodiment 2, in the region bordering the dynamic pressure generating recess 13, the protrusions 30B are arranged in two rows, thereby further reducing the amount of sealed fluid F introduced into the land portion 212 through the groove 14B. Alternatively, the protrusions 30B can also be arranged in a single row.

[0064] Furthermore, on the outer diameter side of the second land portion 212b, a region continuously formed with the pattern of grooves 14A between the protrusions 30A is formed with a pattern of grooves 14C between the protrusions 30C. Specifically, adjacent protrusions 30C contact each other at their base ends, and the grooves 14C formed between these protrusions 30C have a pattern with a flow path cross-sectional area smaller than that of groove 14A and larger than that of groove 14B (see reference). Figure 6 (b)

[0065] Furthermore, in the region of the boundary between the second landmass 212b and the outer space S2, portions of the plurality of protrusions 30D facing the outer space S2 overlap each other, forming a higher density arrangement than the protrusions 30C of the adjacent second landmass 212b. Consequently, the groove 14D formed between these protrusions 30D has a pattern with a flow path cross-sectional area smaller than that of the groove 14C. Additionally, the groove 14D has the same pattern as the groove 14B described above (see...). Figure 6 (a)

[0066] This reduces the amount of sealed fluid F introduced into the land section 212 through grooves 14A to 14C that leaks out through groove 14D, which faces the outer space S2, which is the leakage side. Therefore, the sealing performance between sliding surfaces 211 and 21 can be improved.

[0067] Furthermore, in the second land section 212b, from the sealing side toward the leakage side, there are areas with a pattern of groove 14A, areas with a pattern of groove 14C (smaller than the flow path cross-sectional area of ​​groove 14A), and areas with a pattern of groove 14D (smaller than the flow path cross-sectional area of ​​groove 14C). This improves the sealing performance between the sliding surfaces 211 and 21. Additionally, when the rotary sealing ring 20 stops rotating, the amount of sealed fluid F required to fill the receiving space S3 defined by the grooves 14C and 14D (smaller than the flow path cross-sectional area of ​​groove 14A) and the sliding surface 21 of the rotary sealing ring 20 on the outer diameter side of the sliding surface 211 is reduced. Therefore, at the start of relative rotation and during low-speed rotation, the sliding surfaces 211 and 21 are supplied with sealed fluid F, easily achieving a good lubrication state.

[0068] In this way, by changing the arrangement density of the protrusions 30A to 30D forming the land portion 212 on the sliding surface 211 of the stationary sealing ring 210, multiple regions with different patterns of grooves 14A to 14D are formed. As a result, lubrication and sealing performance can be appropriately controlled according to the required function of each region of the sliding surface 211.

[0069] Furthermore, in this embodiment 2, the method of forming a region with a pattern of groove 14C in the second land portion 212b has been described, but it is not limited to this. It is also possible that the second land portion 212b is formed only with a region with a pattern of groove 14A up to the region with a pattern of groove 14D at its boundary with the outer space S2. Alternatively, a region with a pattern of grooves having a flow path cross-sectional area larger than the flow path cross-sectional area of ​​groove 14A may be formed in the region of the first land portion 212a at the boundary with the inner space S1.

[0070] In addition, the regions of the first land portion 212a and the second land portion 212b that are at the boundary with the dynamic pressure generating recess 13 may also be formed such that only in the outer diameter end where positive pressure is generated and in the vicinity therein, a portion of the plurality of protrusions 30B overlaps with each other, and is configured with a higher configuration density of protrusions 30B than in other regions.

[0071] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the specific structure is not limited to these embodiments. Even if there are changes and additions that do not depart from the spirit of the present invention, they are also included in the present invention.

[0072] For example, in the above embodiment, a mechanical seal used in general industrial machinery was described as a sliding component, but other mechanical seals used in automobiles, etc., can also be used. Furthermore, it is not limited to mechanical seals; it can also be a sliding component other than a mechanical seal, such as a sliding bearing.

[0073] Furthermore, in the above embodiment, an example of providing multiple protrusions forming the land portion and the dynamic pressure generating recess on a stationary sealing ring was described, but multiple protrusions forming the land portion and the dynamic pressure generating recess can also be provided on a rotating sealing ring.

[0074] Furthermore, in the above embodiments, it was described that multiple protrusions forming the land portion are formed approximately equally when the sliding surface is viewed from the axial direction, but this is not a limitation, and each protrusion may also be formed to a different size.

[0075] In addition, the shape of the protrusion is not limited to a dome shape; for example, it can also be formed into other shapes such as a cylinder, prism, cone, or pyramid.

[0076] Furthermore, the case where the protrusions are separated at equal intervals and arranged in an alternating and regular pattern has been described, but it is not limited to this; it can also be as follows: Figure 7 As in the variation of (a), the protrusions are separated at equal intervals and arranged in a lattice pattern and regularly, or as... Figure 7 As in the variation of (b), the protrusions are randomly and irregularly arranged.

[0077] Alternatively, protrusions can also be formed from materials other than ceramic powder, such as resins like PTFE which have low friction properties.

[0078] Furthermore, in the above embodiments, the bottom surface of the dynamic pressure generating recess is described as being formed by the surface of the substrate, but it is not limited thereto. The bottom surface of the dynamic pressure generating recess may also be formed by a laminated surface obtained by laminating the same material as the protrusion on the surface of the substrate.

[0079] Furthermore, in the above embodiments, the case where the dynamic pressure generating recess is an inclined groove communicating with the inner space has been described, but it is not limited to this. As long as dynamic pressure can be generated, the dynamic pressure generating recess may not be communicating with the inner space or the outer space.

[0080] Furthermore, the recesses generated by dynamic pressure are not limited to being formed by inclined grooves; for example, they can also be formed by pits or the like.

[0081] Alternatively, the sliding surface of the sliding component may not have a dynamic pressure generating recess, may have a recess for introducing and retaining fluid, or may not have a recess and instead have multiple protrusions forming the entire sliding surface.

[0082] In addition, the case where the sealed fluid side is the high-pressure side and the leakage side is the low-pressure side is explained, but it is also possible for the sealed fluid side to be the low-pressure side and the leakage side to be the high-pressure side, and the sealed fluid side and the leakage side to be at approximately the same pressure.

[0083] Furthermore, in the above embodiments, the case where the sealed fluid F is a high-pressure liquid has been described, but it is not limited to this. It can also be a gas or a low-pressure liquid, or it can be a mist that is a mixture of liquid and gas.

[0084] Furthermore, in the above embodiments, the fluid on the leakage side was described as atmospheric A, which is a low-pressure gas, but it is not limited to this. It may also be a liquid or a high-pressure gas, or a mist that is a mixture of liquid and gas.

[0085] Furthermore, sliding components are not limited to external mechanical seals, but can also be used in internal mechanical seals.

[0086] Label Explanation

[0087] 10: Stationary sealing ring (sliding component); 10a: Base; 10b: Annular protrusion (substrate); 10c: Flat surface (surface of substrate); 11: Sliding surface; 12: Land portion; 13: Dynamic pressure generating recess; 14: Groove; 14A~14D: Groove; 20: Rotary sealing ring (other sliding components); 21: Sliding surface; 30: Protrusion; 30A~30D: Protrusion; 210: Stationary sealing ring (sliding component); 211: Sliding surface; 212: Land portion; A: Atmosphere; F: Sealed fluid; S1: Inner space (space on the sealing side); S2: Outer space (space on the leakage side); S3: Reception space.

Claims

1. A sliding component disposed at a relatively rotating part of a rotating machine, sliding relative to other sliding components, wherein, The sliding surface of the sliding component has multiple protrusions, and grooves are formed that connect with adjacent protrusions and continue from the sealing side to the leakage side. The sliding surface has a concave portion for generating dynamic pressure. The groove is formed by creating a recess in the face of the dynamic pressure. The density of the protrusions facing the region where the dynamic pressure generates a recess is configured to be higher than the density of the protrusions in the region adjacent to that region.

2. The sliding component according to claim 1, wherein, At least two regions with different densities of the protrusions are formed on the sliding surface.

3. The sliding component according to claim 1 or 2, wherein, A landmass is formed by the assembly of the plurality of protrusions, the landmass having a plurality of first landmasses and an annular second landmass, the plurality of first landmasses being arranged circumferentially, and the annular second landmass being formed to be continuous with each of the first landmasses. The sliding surface has a plurality of dynamic pressure generating recesses, which are respectively divided by opposing side portions of a first land portion adjacent in the circumferential direction and a side portion of a second land portion connected to the side portion. The plurality of concave portions generated by dynamic pressure are respectively connected to the groove.

4. The sliding component according to claim 1 or 2, wherein, The density of the protrusions in the region of the space facing the leakage side is configured to be higher than the density of the protrusions in the region adjacent to that region.

5. The sliding component according to claim 1 or 2, wherein, The plurality of protrusions are arranged in a regular pattern, and each protrusion is dot-shaped.

6. The sliding component according to claim 1 or 2, wherein, The protrusion is fixed to the substrate.

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