Sliding member

Abstract

The invention provides a sliding component which can effectively retain fine wear products in concave strip parts. A sliding member (10), which is disposed at a relative rotation location of a rotary machine and slides relative to another sliding member (20), is provided with a recessed section (14) formed on a sliding surface (11) of the sliding member (10), and a step (15) having a step height difference for capturing a wear product (30) is provided within the recessed section (14).

Description

Technical Field

[0001] The present invention relates to a relatively rotating sliding component, for example, a sliding component used in a shaft sealing device for sealing a rotating shaft of a rotating machine in an automobile, general industrial machinery, or other sealing fields, or a sliding component used in a bearing of an automobile, general industrial machinery, or other bearing-related machinery. Background Art

[0002] As a shaft sealing device for preventing leakage of a sealed fluid, for example, a mechanical seal includes a pair of annular sliding parts that rotate relative to each other and slide on sliding surfaces. In such mechanical seals, in recent years, in order to protect the environment, etc., it is desired to reduce the energy lost due to sliding. Therefore, for example, there is a mechanical seal that allows liquid to flow between the sliding surfaces of the sliding parts to form a fluid film between the sliding surfaces, thereby improving lubricity and achieving low friction.

[0003] For example, Patent Document 1 describes the following. The sliding surface of a sliding component of a mechanical seal has a plurality of tiny grooves arranged at a predetermined pitch width, and a deep groove portion that is arranged across the plurality of grooves and is deeper than the grooves. When a pair of sliding components rotate relative to each other, a convex portion that is a curved surface at the top between the grooves slides against the other sliding surface, generating fine wear products, which are fixed between the convex portion and the other sliding surface to form a transfer layer and are recovered into the grooves. By forming a transfer layer, the transition from severe wear to slight wear can be promoted between the sliding surfaces during relative rotation. In addition, the remaining wear products are discharged into the deep groove.

[0004] In addition, severe wear refers to wear in which the amount of wear increases as the sliding distance increases, and slight wear refers to wear in which the amount of wear hardly increases even if the sliding distance increases. In addition, the wear rate of slight wear is 1 / 10 to 1 / 1000 of the wear rate of severe wear.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2019-108921 (page 5, Figure 1 ) Summary of the invention

[0008] Problems to be solved by the invention

[0009] In the sliding component as disclosed in Patent Document 1, the top of the convex stripe is made into a curved surface, so that fine wear products are easily generated and a transfer layer is easily formed between the convex stripe and the other sliding surface. However, the fine wear products move along the concave stripe and are easily discharged to the outside of the sliding area through the deep groove portion, and the fine wear products cannot be effectively retained in the concave stripe. Therefore, it may take time to form a transfer layer from the fine wear products.

[0010] The present invention has been made in view of such problems, and an object of the present invention is to provide a sliding member capable of effectively retaining fine wear products in grooves.

[0011] Means for solving problems

[0012] In order to solve the above-mentioned problems, the sliding component of the present invention is:

[0013] It is arranged at the relative rotating part of the rotating machine and slides relative to other sliding parts, wherein:

[0014] A concave portion is formed on the sliding surface of the sliding component.

[0015] A step having a height difference for catching wear products is provided in the groove portion.

[0016] Thus, the wear products flowing along the grooves are captured and accumulated by the steps of the grooves, so that the fine wear products can be effectively retained in the grooves as lubricants.

[0017] The concave stripe portion may be provided in plurality independently in the radial direction.

[0018] Thus, the grooves are not connected to the external space, so it is possible to prevent wear products from being discharged from the grooves to the external space. In addition, the force generated at the grooves during relative rotation of the sliding surfaces acts evenly in the radial direction, so it is easy to keep the sliding surfaces roughly parallel to each other.

[0019] Alternatively, the concave stripe portion is in a seamless ring shape.

[0020] Thus, the step makes it easy to capture the wear products around the grooves. In addition, the force generated at the grooves during the relative rotation of the sliding surfaces acts evenly in the circumferential direction, so it is easy to keep the sliding surfaces substantially parallel to each other.

[0021] Alternatively, the bottom of the concave strip portion may be curved in a concave direction.

[0022] This makes it easier to guide the wear products moving along the bottom of the groove portion toward the step.

[0023] A plurality of the steps may be arranged at intervals in the longitudinal direction of the groove.

[0024] This ensures that the wear area of ​​the sliding surface is maintained and that the wear products are deposited evenly in the longitudinal direction of the grooves.

[0025] A recess may be provided at the bottom of the groove portion, and a part of the recess may constitute the step.

[0026] Thus, a large space for accommodating fine wear products can be ensured by the dimples. In addition, the step can be easily formed.

[0027] Alternatively, the dimple may be circular when viewed from the axial direction.

[0028] Thus, wear products are easily captured in the dimples.

[0029] The sliding member may be made of SiC.

[0030] Thus, since SiC has high hydrophilicity and the surface area of ​​the wear products is large, water can be appropriately retained around the grooves and steps. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a longitudinal sectional view showing an example of a mechanical seal in Embodiment 1 of the present invention;

[0032] Figure 2 is a diagram of the sliding surface of the stationary sealing ring observed from the axial direction;

[0033] Figure 3 (a) Yes Figure 2 AA cross-section of (b) Figure 2 BB cross-section diagram;

[0034] Figure 4 (a) is a schematic diagram of a concave groove when the sliding member rotates relative to each other as viewed from the axial direction, and (b) is a CC cross-sectional view of (a);

[0035] Figure 5 (a) Observed from the axial direction Figure 4 , (b) is a DD cross-sectional view of (a);

[0036] Figure 6 (a) Observed from the axial direction Figure 5 ) is a schematic diagram of a state in which the sliding part is relatively rotated compared to the state in which the sliding part is relatively rotated, and (b) is an EE cross-sectional view of (a);

[0037] Figure 7 yes Figure 6 (b) FF cross-section;

[0038] Figure 8 is a schematic diagram of an example of a state of a concave groove when a mechanical seal is normally operated for a long time as viewed from the axial direction, (b) is a JJ cross-sectional view of (a);

[0039] Fig. 9 is an explanatory diagram showing a stationary seal ring in a modification 1 of the embodiment 1;

[0040] Fig.10 is an explanatory diagram showing a stationary seal ring in a second variation of the first embodiment;

[0041] Fig.11 (a) to (d) are explanatory diagrams showing dimples in Modifications 3 to 6 of Example 1;

[0042] Fig.12 (a) to (f) are explanatory diagrams showing dimples in Modifications 7 to 12 of Example 1;

[0043] Fig.13 is a schematic diagram of a concave groove in Example 2 of the present invention observed from the axial direction, (b) is a GG cross-sectional view of (a), and (c) is a HH cross-sectional view of (a);

[0044] Fig.14 is an explanatory diagram showing a stationary seal ring in Embodiment 3 of the present invention;

[0045] Fig.15 (a) Yes Fig.14 KK cross-section diagram, (b) is also Fig.14 LL cross-sectional view. DETAILED DESCRIPTION

[0046] Hereinafter, modes for implementing the sliding member of the present invention will be described based on examples.

[0047] [Example 1]

[0048] Reference Figures 1 to 7 The sliding component of Example 1 is described. In addition, in this embodiment, the sliding component is described as a mechanical seal. In addition, the outer diameter side of the sliding component constituting the mechanical seal is described as the sealed fluid side (high pressure side), and the inner diameter side is described as the leakage side, that is, the atmosphere side (low pressure side). In addition, for the convenience of description, the grooves formed on the sliding surface are sometimes marked with dots in the drawings.

[0049] Figure 1The mechanical seal shown is used, for example, in a shaft seal device in a motor cooling system of an electric vehicle, and is an inner type mechanical seal that seals a sealed fluid F that leaks from the outer diameter side of the sliding surface to the inner diameter side. In this embodiment, the sealed fluid F is cooling water.

[0050] The mechanical seal is mainly composed of the following components: a rotating seal ring 20 as an annular sliding component, which is arranged on the rotating shaft 1 via a sleeve 2 so as to be able to rotate integrally with the rotating shaft 1; and an annular stationary seal ring 10 as a sliding component, which is arranged on a sealing cover 5 fixed to a housing 4 of the mounted device in a non-rotating state and axially movable state, and the stationary seal ring 10 is axially urged by the bellows 7, whereby the sliding surface 11 of the stationary seal ring 10 and the sliding surface 21 of the rotating seal ring 20 slide in close contact with each other. In addition, the sliding surface 21 of the rotating seal ring 20 is a flat surface, and no recess is provided on the flat surface.

[0051] The stationary seal ring 10 and the rotating seal ring 20 are typically formed of SiC (hard material) or a combination of SiC (hard material) and carbon (soft material), but are not limited to this. Any sliding material that is used as a sliding material for a mechanical seal can be used. In addition, as SiC, there are sintered bodies using boron, aluminum, carbon, etc. as sintering aids, and materials composed of two or more phases with different components and compositions, such as SiC with graphite particles dispersed, reaction sintered SiC composed of SiC and Si, SiC-TiC, SiC-TiN, etc. As carbon, carbon mixed with carbon and graphite is represented, and resin-formed carbon, sintered carbon, etc. can be used. In addition, in addition to the above-mentioned sliding materials, metal materials, resin materials, surface modification materials (coating materials), composite materials, etc. can also be used. As described later, from the perspective of water retention, materials with SiC as the main component are preferred.

[0052] like Figure 2 As shown, the rotating seal ring 20 slides relative to the stationary seal ring 10 as shown by the arrow. A plurality of concave grooves 14 as concave portions are provided on the sliding surface 11 of the stationary seal ring 10. The portion of the sliding surface 11 other than the concave grooves 14 is a shoulder 12, and the concave grooves 14 and the shoulder 12 are alternately arranged in the radial direction.

[0053] like Figure 2 and Figure 3As shown, these concave grooves 14 are in the form of an endless ring, and are spaced apart in the radial direction at a predetermined pitch width and are provided concentrically with the sliding surface 11. That is, each concave groove 14 is independently provided in the radial direction in a plurality of ways, and the concave grooves are not connected to each other. Each concave groove 14 has a radial width dimension L1. In addition, the concave groove 14 has a certain depth dimension L5 in the circumferential direction and in the radial direction. In addition, for the sake of convenience of explanation, the depth of the concave groove 14 and the depth of the dent 15 described later are shown schematically and are deeper than the actual depth.

[0054] The radial width dimension L2 of the shoulder 12 is slightly smaller than the radial width dimension L1 of the groove 14 (L1>L2). In addition, in this embodiment, the width dimension L2 of the shoulder 12 is smaller than the width dimension L1 of the groove 14, but the width of the shoulder between the grooves can also be larger than the width of the groove, and the width of the shoulder can also be the same as the width of the groove. From the viewpoint of forming the terrace layer 16 described later, the width dimension L1 of the shoulder is preferably larger than 1 / 3 times and smaller than 3 times the width dimension L2 of the groove (1 / 3L2<L1<3L2).

[0055] In addition, the top portion 12 a of the shoulder 12 is curved so as to be convex toward the rotary seal ring 20 side.

[0056] The bottom 14a of the concave groove 14 faces the concave direction, that is, the direction opposite to the end surface of the shoulder 12 (i.e. Figure 3 bend in the lower part of the figure.

[0057] At the bottom 14a of the concave groove 14, a plurality of dimples 15 are evenly arranged in the longitudinal direction of the concave groove 14, that is, in the circumferential direction. The dimples 15 are arranged radially from the relative rotation center O of the sliding surface 11 when viewed from the axial direction. The dimples 15 are hemispherical in shape opening to the concave groove 14, and are C-shaped in cross section upward, and are circular when viewed from the axial direction.

[0058] The diameter dimension L3 of the dimple 15 is slightly smaller than the width dimension L1 of the groove 14 (L1>L3). In addition, the diameter dimension L3 of the dimple 15 may be the same as or larger than the width dimension L1 of the groove 14, but from the viewpoint of forming the terrace layer 16 described later, the diameter dimension L3 of the dimple 15 is preferably larger than 1 / 3 times the width dimension L1 of the groove 14 and smaller than the width dimension L1 of the groove 14 (1 / 3L1<L3≤L1).

[0059] In addition, the depth dimension L4 of the dimple 15 is smaller than the depth dimension L5 of the groove 14 (L4<L5). In addition, the depth dimension L4 of the dimple 15 may be the same as or larger than the depth dimension L5 of the groove 14, but from the viewpoint of forming the terrace layer 16 described later, it is preferably larger than 1 / 3 times and smaller than 3 times the depth dimension L5 of the groove 14 (1 / 3L5<L4≤3L5).

[0060] The stationary seal ring 10 of this embodiment is configured by forming the concave groove 14 on the sliding surface 11 and then forming the dimple 15 on the bottom 14a of the concave groove 14. Alternatively, the concave groove 14 may be formed after the dimple 15 is formed on the sliding surface 11.

[0061] Next, use Figures 4 to 6 The operation of the stationary seal ring 10 and the rotating seal ring 20 during the relative rotation during the running-in operation performed before the normal operation of the mechanical seal will be described. Figures 4 to 6 In the embodiment, the movement of the sealed fluid F and the wear product 30 in one concave groove 14 is described. Figures 4 to 6 In FIG. 1 , the height change caused by the wear of the shoulder 12 is illustrated as being larger than it actually is.

[0062] First, when the rotary seal ring 20 is not rotating and is not in operation, the sealed fluid F is stored in the concave grooves 14. Furthermore, since the stationary seal ring 10 is urged toward the rotary seal ring 20 by the bellows 7, almost no fluid leaks from between the sliding surfaces 11 and 21 to the low pressure side.

[0063] like Figure 4 As shown in FIG. 1 , when the rotating seal ring 20 rotates relative to the stationary seal ring 10, the sealed fluid F stored in the concave groove 14 moves in the rotation direction of the rotating seal ring 20 (see arrow) due to friction with the sliding surface 21. Specifically, the sealed fluid F moves along the concave groove 14 extending in the relative rotation direction with the rotating seal ring 20. In addition, Figure 4 The height of the shoulder 12 in the state is dimension L10.

[0064] At this time, the shoulder 12 of the stationary seal ring 10 partially contacts the flat surface of the sliding surface 21 of the rotating seal ring 20, thereby generating minute wear products 30. As described above, the top 12a of the shoulder 12 is curved so as to be convex toward the rotating seal ring 20, so that the formation of large wear products can be suppressed. The wear products 30 may be from the stationary seal ring 10 or the rotating seal ring 20, or may be a mixture of them.

[0065] The minute wear products 30 move along the concave grooves 14 together with the sealed fluid F. A portion of the wear products 30 moving along the concave grooves 14 is captured in the dimples 15. Specifically, the surface on the relatively rotationally downstream side of the dimples 15 is arranged at a lower position than the bottom 14a of the concave grooves 14, and the wear products 30 are captured by the surface.

[0066] In addition, due to the sliding between the top 12a of the shoulder 12 and the sliding surface 21 of the rotary seal ring 20, the top 12a of the shoulder 12 is worn to form a platform layer 16 (see Figure 7 ).

[0067] The platform layer 16 and the sliding surface 21 are well matched and can be in a low wear state.

[0068] like Figure 5 As shown, when the rotating seal ring 20 moves relative to the stationary seal ring 10 Figure 4 When the bearing 10 further rotates relatively in the state of being rotated, the wear products 30 are further captured in the dimples 15 .

[0069] in addition, Figure 5 The height of the shoulder 12 in the state becomes a dimension L10' which is smaller than the dimension L10 (L10>L10') due to wear.

[0070] like Figure 6 As shown, when the rotating seal ring 20 moves relative to the stationary seal ring 10 Figure 5 When the state is further relatively rotated, the wear products 30 are accumulated in the dimples 15 and are accumulated in layers at the bottom 14a of the grooves 14. That is, a large amount of wear products 30 exist at the bottom 14a of the grooves 14 and around the dimples 15. Figure 6 The height of the shoulder 12 in the state becomes a dimension L10 which is smaller than the dimension L10' (L10'>L10").

[0071] The running-in operation is completed when the friction coefficient becomes below a predetermined value after a predetermined time has passed. In this completed state, the terrace layer 16 is fully formed, and the lubricity between the sliding surfaces 11 and 21 is good. In addition, normal operation is performed after the running-in operation.

[0072] When the mechanical seal is in normal operation for a long time, such as Figure 8As shown in FIG. 1 , the wear of the shoulder 12 is aggravated, and the wear products 30 may be deposited in almost the entire concave groove 14. In this state, the layer of the wear products 30 deposited in the concave groove 14 is more easily deformed by external force than the shoulder 12, so the force received by the rotating seal ring 20 is mainly borne by the shoulder 12. In addition, the layer of the wear products 30 deposited in the concave groove 14 has a large number of gaps between the wear products 30, which can ensure a large surface area, and the wear products 30 are mainly composed of SiC, so a large amount of sealed fluid F can be retained. As a result, the state of high lubricity between the sliding surfaces 11 and 21 can be maintained.

[0073] As described above, the wear products 30 flowing along the grooves 14 are captured and accumulated by the dimples 15 provided in the grooves 14 , so that the fine wear products 30 serving as lubricants can be effectively retained in the grooves 14 .

[0074] In addition, since the sealed fluid F can be retained in the minute gaps between the wear products 30 , the lubricity between the sliding surfaces 11 , 21 is improved.

[0075] In addition, a plurality of concave grooves 14 are independently provided in the radial direction. In other words, the concave grooves 14 are not connected to the sealed fluid F side or the atmosphere A side as the external space, so that the wear products 30 can be prevented from being discharged from the concave grooves 14 to the sealed fluid Fa side or the atmosphere A side. Therefore, the fine wear products 30 can be effectively retained in the concave grooves 14.

[0076] When the sliding surfaces 11 and 21 rotate relative to each other, positive pressure or negative pressure may be generated in a part of the concave groove 14. When positive pressure or negative pressure is generated in the concave groove 14, a force acts on the sliding surfaces 11 and 21 in a direction to separate them from each other or in a direction to approach them, and this force acts evenly in the radial direction of the sliding surfaces 11 and 21, so that the sliding surfaces 11 and 21 are easily kept substantially parallel to each other.

[0077] In addition, the concave groove 14 is in the shape of an endless ring, so the wear products 30 surrounding the concave groove 14 are easily captured by the dimples 15. In addition, the force generated by the concave groove 14 in the direction of separating or approaching the sliding surfaces 11 and 21 acts evenly in the circumferential direction of the sliding surfaces 11 and 21, so it is easy to keep the sliding surfaces 11 and 21 substantially parallel to each other. In addition, no circumferential end portion is formed on the concave groove 14, so it is possible to prevent the wear products 30 from being concentrated and accumulated at the end portion.

[0078] Furthermore, since the bottom 14 a of the concave groove 14 is curved in the concave direction, that is, in the direction opposite to the end surface of the shoulder 12 , the wear product 30 moving along the concave groove 14 is guided toward the dimple 15 by the bottom 14 a .

[0079] In addition, since a plurality of dimples 15 are evenly arranged in the longitudinal direction of the groove 14, the wear products 30 can be dispersed and evenly accumulated in the longitudinal direction of the groove 14. In addition, since the dimples 15 are spaced apart in the circumferential direction, the wear area where the wear products 30 are generated on the sliding surfaces 11 and 21 can be ensured.

[0080] In addition, the step for catching the wear product 30 is that the bottom 14a of the concave groove 14 is provided with the dimple 15, and the surface constituting the relatively rotation downstream side of the dimple 15 catches the wear product 30. Thus, the dimple 15 is a recessed portion that is recessed in the depth direction more than the bottom 14a of the concave groove 14, so that a large space for accommodating the fine wear product 30 can be ensured. In addition, since the dimple 15 has a simple shape, it can be easily formed.

[0081] Furthermore, since the dimples 15 are circular in shape and have no corners when viewed from the axial direction, the wear products 30 can be easily captured in a balanced manner in the dimples 15 .

[0082] Furthermore, the stationary seal ring 10 is made of SiC, and SiC wear products 30 have high hydrophilicity. In addition, the fine wear products 30 have a large surface area, so water can be appropriately retained around the grooves 14 and dimples 15, and lubricity can be improved.

[0083] In the first embodiment, the dimples 15 are arranged radially from the relative rotation center O of the sliding surface 11 when viewed from the axial direction, but the present invention is not limited thereto. For example, the dimples 15 may be arranged radially from the relative rotation center O of the sliding surface 11 when viewed from the axial direction. Fig. 9 As in the stationary seal ring 100 of the first modification shown, the dimples 151 are randomly formed so as to be arranged unevenly in the longitudinal direction of the concave groove 14 .

[0084] In the first embodiment, the dimples 15 are provided only in the grooves 14, but the present invention is not limited thereto. The dimples may be provided at least in the grooves 14, or may be provided across the shoulder 12 and the grooves 14. Fig.10 Like the stationary seal ring 101 of the second modification shown, a dimple 251 a provided at the bottom 14 a of the groove 14 , a dimple 251 b provided at the shoulder 12 , and a dimple 251 c provided across the groove 14 and the shoulder 12 are formed.

[0085] Although not shown in the drawings, the dimples may be provided so as to be scattered in a lattice pattern on the sliding surface.

[0086] In the first embodiment, the dimple 15 is exemplified as being in a hemispherical shape curved in the concave direction when viewed from a cross section, but the present invention is not limited thereto. Fig.11 and Fig.12 In the figure, the up-down direction on the paper is referred to as the circumferential direction, and the left-right direction on the paper is referred to as the radial direction.

[0087] For example, you can also Fig.11 As shown in (a) in the modification 3, the dimple 300 has a shallower crescent shape than the dimple 15 of the embodiment 1 when viewed from the cross section.

[0088] In addition, for example, Fig.11 As indentation 301 of modification example 4 shown in (b), it is U-shaped when viewed from a cross section.

[0089] In addition, for example, Fig.11 Like the dimple 302 of the modification 5 shown in (c), it has a rectangular shape when viewed from a cross section.

[0090] In addition, for example, Fig.11 Like the dimple 303 of the modification 6 shown in (d), it has a triangular shape when viewed from a cross section.

[0091] In the above-mentioned embodiment 1, the dimple 15 is exemplified as being circular when viewed from the axial direction, but the present invention is not limited thereto. Fig.12 As in the case of the dimple 400 of the modification 7 shown in (a), the dimple 400 is elliptical when viewed from the axial direction. In addition, the dimple 400 may be an ellipse that is long in the circumferential direction or an ellipse that is long in the radial direction.

[0092] In addition, for example, Fig.12 (b) shows a long hole shape having curved surfaces 401a protruding toward the outside of the dimple 401 at both ends in the longitudinal direction when viewed from the axial direction. In addition, the dimple 401 may be long in the circumferential direction or long in the radial direction. In addition, the curved surface 401a may be formed to protrude toward the inside of the dimple 401.

[0093] In addition, for example, Fig.12 Like the dimple 402 of the modification 9 shown in (c), it is a rectangular shape that is long in the radial direction when viewed from the axial direction.

[0094] In addition, for example, Fig.12 (d) When viewed from the axial direction, the dimples are rectangular and long in the circumferential direction, as in the dimples 403 of the modification 10 shown in FIG. Although not shown in the figure, the dimples may be square when viewed from the axial direction.

[0095] In addition, for example, Fig.12(e) shows a long hole shape having curved surfaces 404a protruding toward the inside of the dimple 404 at both ends in the short side direction when viewed from the axial direction. In addition, the dimple 404 may be long in the circumferential direction or long in the radial direction. In addition, the curved surface 404a may be formed to protrude toward the outside of the dimple 404.

[0096] In addition, for example, Fig.12 As in the case of the dimple 405 of the modification 12 shown in (f), the dimple 405 is formed in a sawtooth shape when viewed from the axial direction. In addition, the corners of the dimple 405 may be curved surfaces.

[0097] [Example 2]

[0098] Next, refer to Fig.13 The sliding member of Example 2 will be described. In addition, the same structure as that of the above-mentioned Example 1 will be omitted and repeated description will be omitted.

[0099] like Fig.13 As shown, the stationary seal ring 110 of this embodiment has a wall portion 152 erected from the bottom 142a of the groove 142 to the side 142b of the groove 142, i.e., the side of the shoulder 12. The wall portion 152 has a height dimension smaller than that of the shoulder 12.

[0100] The wall portion 152 captures the wear product 30 moving along the concave groove 142, and thus the wear product 30 can be effectively retained in the concave groove 142. That is, the wall portion 152 functions as a step for capturing the wear product.

[0101] In addition, the wall portion 152 is not limited to being formed across the bottom 142a of the groove 142 to the side 142b of the groove 142. For example, the wall portion may be separated from the side of the groove and stand up from the bottom of the groove. That is, the wall portion only needs to be a step that can capture the wear products.

[0102] [Example 3]

[0103] Next, refer to Fig.15 The sliding member of Example 3 will be described. In addition, the same structure as that of the above-mentioned Example 1 will be omitted and repeated description will be omitted.

[0104] like Fig.14 and Fig.15 As shown in (a) and (b), a plurality of concave grooves 514 having the same depth are provided on the sliding surface 511 of the stationary seal ring 510 of this embodiment. Portions of the sliding surface 511 other than the concave grooves 514 form shoulders 512 having the same height.

[0105] Specifically, one concave groove 514 extends radially in a manner obliquely passing through the relative rotation center O of the sliding surface 511 when viewed from the axial direction. The other concave grooves 514 extend substantially parallel to the one concave groove 514 and are formed to be spaced apart by a predetermined pitch width. That is, each concave groove 514 extends in a direction intersecting the axial direction. In other words, each concave groove 514 extends obliquely with respect to the circumferential direction of the sliding surface 511.

[0106] In addition, the concave groove 514 is formed by laser processing the surface of the base material of the stationary seal ring 510. When the laser processing is performed, an amorphous layer 516 is formed on the surface. This amorphous layer 516 is easy to peel off. That is, the sliding surface 511 is easy to generate wear products. In addition, in Examples 1 and 2, by forming the concave grooves 14 and 142 by laser processing, it is also possible to make the sliding surface 511 easy to generate wear products.

[0107] like Fig.14 and Fig.15 As shown in (a), at the bottom 514a of each concave groove 514, a plurality of dimples 515 are evenly arranged at intervals in the longitudinal direction of the concave groove 514. The dimples 515 are arranged radially from the relative rotation center O of the sliding surface 511 when viewed from the axial direction. In addition, the arrangement of the dimples may be random, radial, or lattice-like.

[0108] When the rotary seal ring 20 rotates relative to the stationary seal ring 510, the wear products flow along the grooves 514 and accumulate in the dimples 515 and the bottom 514a. SiC wear products have high hydrophilicity, and the accumulated wear products can appropriately retain water, thereby improving lubricity.

[0109] Furthermore, in the third embodiment, one concave groove 514 extends radially in a manner obliquely passing through the relative rotation center O of the sliding surface 511 when viewed from the axial direction, and the other concave grooves 514 extend approximately parallel to the one concave groove 514 and are formed spaced apart by a predetermined pitch width. However, for example, in addition to the above-mentioned concave grooves 514 (one concave groove 514 and other concave grooves 514), a plurality of other concave grooves 514 may be provided in a manner intersecting with the above-mentioned concave grooves 514, and the concave grooves 514 may be orthogonal to each other, or the concave grooves 514 may not be orthogonal to each other but merely intersect with each other.

[0110] In addition, in the third embodiment, the method of forming the concave groove 515 in the concave groove 514 is exemplified, but for example, it is also possible to form the concave groove 515 in the concave groove 514 as in the second modification (see Fig.10 ) is arranged across the shoulder, groove and shoulder.

[0111] As mentioned above, although the embodiment of the present invention is described based on the drawings, the specific structure is not limited to these embodiments, and even if there are changes and additions within the scope that does not depart from the gist of the present invention, they are also included in the present invention.

[0112] For example, in the above-mentioned embodiments 1 to 3, a method of independently providing a plurality of concave grooves is illustrated, but it is sufficient to provide at least one concave groove. In addition, the concave grooves of the above-mentioned embodiments 1 and 2 may be partially connected to the external space on the outer diameter side or the external space on the inner diameter side, and the concave groove of the above-mentioned embodiment 3 may not be connected to the external space on the outer diameter side or the external space on the inner diameter side.

[0113] In addition, in the above-mentioned embodiments 1 and 2, the concave groove is exemplified as being in a seamless ring shape, and in the above-mentioned embodiment 3, the groove is exemplified as extending in a direction intersecting the axial direction, but it may also be, for example, a groove extending in the circumferential direction, a groove extending in the radial direction, or a groove having a component extending in the radial direction and a component extending in the circumferential direction, etc.

[0114] In addition, in the above-mentioned embodiments 1 and 2, the groove portion is exemplified as having a constant depth in the circumferential direction, and in the above-mentioned embodiment 3, the groove portion is exemplified as having a constant depth in the longitudinal direction, but for example, the groove portion may be tapered in such a way that a portion of the bottom becomes shallower or deeper toward one side relative to the rotation direction.

[0115] In addition, in the above-mentioned embodiments 1 to 3, the sliding parts are described by taking the mechanical seal for automobile as an example, but other mechanical seals for general industrial machinery, water pumps, etc. can also be used. In addition, it is not limited to mechanical seals, and it can also be sliding parts other than mechanical seals such as sliding bearings.

[0116] In the above-mentioned first to third embodiments, the examples in which the concave grooves are provided only in the stationary seal ring are described. However, the concave grooves may be provided only in the rotating seal ring, or may be provided in both the stationary seal ring and the rotating seal ring.

[0117] In addition, in the above-mentioned embodiments 1 to 3, the sealed fluid side is described as the high-pressure side and the leakage side as the low-pressure side, but the sealed fluid side may be the low-pressure side and the leakage side may be the high-pressure side, or the sealed fluid side and the leakage side may be at approximately the same pressure.

[0118] In addition, in the above-mentioned embodiments 1 to 3, an inner-type mechanical seal that seals the sealed fluid F that leaks from the outer diameter side of the sliding surface to the inner diameter side is illustrated, but it is not limited to this. It can also be an outer-type mechanical seal that seals the sealed fluid F that leaks from the inner diameter side of the sliding surface to the outer diameter side.

[0119] In the above-mentioned embodiments 1 to 3, the sealed fluid F is cooling water, but the present invention is not limited thereto. The sealed fluid may be liquid or a mist of a mixture of liquid and gas, such as lubricating oil.

[0120] Explanation of symbols

[0121] 10: stationary sealing ring (sliding part); 11: sliding surface; 12: shoulder; 12a: top; 14: groove (groove part); 14a: bottom; 15: dent (step); 16: platform layer; 20: rotating sealing ring; 21: sliding surface; 30: wear product; 100: stationary sealing ring; 110: stationary sealing ring; 142: groove; 142a: bottom; 142b: side; 151: dent; 152: wall; A: atmosphere; C: cross section upward; F: sealed fluid; Fa: sealed fluid; L1: width dimension; L10: dimension; L10': dimension; L10": dimension; L2: width dimension; L3: diameter dimension; L4: depth dimension; L5: depth dimension.

Claims

1. A sliding component, which is arranged at a relatively rotating part of a rotary machine and slides relatively with other sliding components, wherein: A concave portion is formed on the sliding surface of the sliding component. A step having a height difference for catching wear products is provided in the groove portion.

2. The sliding component according to claim 1, wherein: A plurality of the concave stripes are independently provided in the radial direction.

3. The sliding component according to claim 1, wherein: The concave strip portion is in a seamless ring shape.

4. The sliding component according to claim 1, wherein: The bottom of the concave strip portion is bent in a concave direction.

5. The sliding component according to claim 1, wherein: A plurality of the steps are arranged at intervals in the longitudinal direction of the groove.

6. The sliding component according to any one of claims 1 to 5, wherein: A recess is disposed at the bottom of the groove portion, and a portion of the recess constitutes the step.

7. The sliding component according to claim 6, wherein: The dimple is circular when viewed from the axial direction.

8. The sliding component according to claim 1, wherein The sliding member is made of SiC.

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