Sliding member

Abstract

The invention provides a sliding component capable of reducing damage of a sliding surface. In a sliding member (1) in which a pair of seal rings (3, 5) are arranged so as to rotate relative to each other, a sliding surface (S1) of each seal ring (5) has formed thereon: a shoulder surface (9) that extends in the circumferential direction so as to be able to come into contact with an opposing sliding surface (S2); a recessed section (11) that is recessed in the axial direction, extends to the inner diameter side, and opens to the inner diameter side; and an outer recess (12) that is recessed in the axial direction, extends to the outer diameter side, and opens to the outer diameter side.

Description

[0001] This application is a divisional application of the Chinese application with an application date of August 25, 2020, application number 202080059723.2, and invention name “Sliding Part”. Technical Field

[0002] 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 fields. Background Art

[0003] Sliding parts used in shaft sealing devices and bearings form sliding surfaces smoothly, thereby reducing durability and energy loss. For example, as a shaft sealing device that prevents leakage of a sealed fluid, a mechanical seal includes a pair of annular seal rings that rotate relative to each other and slide on their sliding surfaces. As an example of such a mechanical seal, Patent Document 1 discloses a seal having a static seal ring and a rotating seal ring, and having a plurality of small recesses formed on the sliding surface of one of the seal rings.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2017-207209 (page 5, Figure 1 ) Summary of the invention

[0007] Problems to be solved by the invention

[0008] When the sliding parts such as patent document 1 are in use, the sealed fluid is kept in the small recess, thereby the sealed fluid is between the sliding surfaces and the friction generated between the sliding surfaces is reduced, and each sliding surface is not easy to wear. In addition, the sliding surface is microscopically concave and convex, and a part of the convex part is defective, thereby generating fine wear powder, which flows into any small recess and is recovered. On the other hand, microscopically, the sliding surface forms a physicochemically stable surface layer, but the defective part of the partially defective convex part becomes the base of the sliding part exposed, and becomes more active than the surface layer, and is easy to combine with other components, such as the defective wear powder. In addition, since the wear powder recovered in the small recess can flow out from the small recess again to between the sliding surfaces through the relative movement between the sliding parts, it is easy to remain between the sliding surfaces, causing the sliding surfaces of other parts to have accumulation parts, thereby the sliding surface may be easily damaged.

[0009] The present invention has been made in view of such problems, and an object of the present invention is to provide a sliding component capable of reducing damage to a sliding surface.

[0010] Means for solving problems

[0011] In order to solve the above-mentioned problems, the sliding component of the present invention has a pair of seal rings arranged to rotate relatively.

[0012] The sliding surface of the sealing ring is formed with: a shoulder surface extending in the circumferential direction capable of contacting the opposite sliding surface; an inner recessed portion recessed in the axial direction and extending to the inner diameter side and open to the inner diameter side; and an outer recessed portion recessed in the axial direction and extending to the outer diameter side and open to the outer diameter side.

[0013] Thus, at least an inner concave portion and an outer concave portion are arranged in the circumferential direction, so that the wear powder generated on the shoulder surface as the pair of seal rings rotate relative to each other moves with the relative rotation, is recovered by the inner concave portion or the outer concave portion, and is quickly discharged to the outside, thereby reducing the damage to the sliding surface.

[0014] The inner recessed portion and the outer recessed portion may overlap in the circumferential direction.

[0015] Thus, along with the relative rotation of the pair of seal rings, the wear powder lost on the shoulder surface can be easily and reliably recovered by the inner recess or the outer recess.

[0016] The outer end of the inner recessed portion and the inner end of the outer recessed portion may coincide with each other in the circumferential direction.

[0017] Thus, along with the relative rotation of the pair of seal rings, the wear powder lost on the shoulder surface can be easily and reliably recovered by the inner recess or the outer recess.

[0018] The inner recessed portions and the outer recessed portions may be arranged alternately and at equal intervals in the circumferential direction.

[0019] Thus, along with the relative rotation of the pair of seal rings, the wear powder lost on the shoulder surface can be easily and reliably recovered by the inner recess or the outer recess.

[0020] Alternatively, the inner recess and the outer recess may be in line-symmetrical shapes with respect to their respective radial lines.

[0021] As a result, wear powder can be reliably recovered regardless of the rotation direction.

[0022] The inner recessed portion may be formed so that its width increases toward the inner diameter side, and the outer recessed portion may be formed so that its width increases toward the outer diameter side.

[0023] Thus, the wear powder recovered in the inner recessed portion can be easily discharged to the inner diameter side of the sliding surface, and the wear powder recovered in the outer recessed portion can be easily discharged to the outer diameter side of the sliding surface.

[0024] The inner recessed portion and the outer recessed portion may each have a curved peripheral edge.

[0025] This makes it easy to smoothly release the wear powder recovered in the inner recess or the outer recess to the inner diameter side or the outer diameter side of the sliding surface.

[0026] The shoulder surface, the inner recessed portion, and the outer recessed portion may be formed on one of the seal rings.

[0027] Thus, the relative positions of the shoulder surface, the inner recessed portion, and the outer recessed portion are not deviated, so that not only the structure is simple, but also reliable sealing can be performed between the inner diameter side and the outer diameter side.

[0028] Alternatively, the shoulder surface may extend in the entire circumferential direction.

[0029] Thereby, the sealing property can be improved.

[0030] The inner recessed portion and the outer recessed portion may have circumferential dimensions longer than their respective axial dimensions.

[0031] This makes it easier to release the wear powder recovered in the inner recess or the outer recess toward the inner diameter side or the outer diameter side of the sliding surface.

[0032] The shoulder surface may be formed of a DLC (Diamond Like Carbon) film or a TiN film.

[0033] This makes it possible to form the height of the shoulder surface and to easily reduce the friction coefficient generated between the sliding surfaces. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a longitudinal sectional view showing an example of a mechanical seal in Embodiment 1 of the present invention;

[0035] Figure 2 (a) is a diagram showing the sliding surface of the static seal ring as viewed from the axial direction, and (b) is a diagram for explaining a region of the sliding surface of the static seal ring that is opposite to the sliding surface of the rotary seal ring;

[0036] Figure 3 (a) Yes Figure 2 (a) is the α-α cross-section, (b) is Figure 2 (a) is the β-β cross-section diagram, (c) is Figure 2 (a) γ-γ cross-section;

[0037] Figure 4 (a) to (d) are schematic diagrams showing the state of the sliding surface after grinding at a microscopic level;

[0038] Figure 5(a) to (e) are schematic diagrams for explaining the discharge of wear powder;

[0039] Figure 6 (a) is a diagram showing the sliding surface of a static seal ring in Example 2 of the present invention as viewed from the axial direction, and (b) is a diagram for explaining a region of the sliding surface of the static seal ring in Example 2 of the present invention that is opposite to the sliding surface of the rotary seal ring;

[0040] Figure 7 (a) is a diagram showing the sliding surface of a static seal ring in Example 3 of the present invention as viewed from the axial direction, and (b) is a diagram for explaining a region of the sliding surface of the static seal ring in Example 3 of the present invention that is opposite to the sliding surface of the rotary seal ring;

[0041] Figure 8 (a) is a diagram showing the sliding surface of a static seal ring in Example 4 of the present invention as viewed from the axial direction, and (b) is a diagram for explaining a region of the sliding surface of the static seal ring in Example 4 of the present invention that faces the sliding surface of a rotary seal ring. DETAILED DESCRIPTION

[0042] Hereinafter, modes for implementing the sliding member of the present invention will be described based on examples.

[0043] Example 1

[0044] Reference Figures 1 to 5 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 seal ring constituting the mechanical seal is set as the sealed liquid side (high pressure side) as the sealed fluid side, and the inner diameter side is set as the atmosphere side (low pressure side) as the leakage side. In addition, for the convenience of description, in the drawings, points are sometimes added to the recessed portion formed on the sliding surface.

[0045] Figure 1 The mechanical seal 1 for general industrial machinery shown is an inner-shaped seal that seals the sealed liquid L that is about to leak from the outer diameter side of the sliding surface to the inner diameter side, and has: a static seal ring 5 as an annular seal ring, which is a sliding component arranged on the housing 4 of the installed equipment in a non-rotating state and axially movable state; and a rotating seal ring 3 as an annular seal ring, which is a sliding component on the side of the rotating shaft 8 that drives the pump impeller (not shown) on the high-pressure fluid side and can rotate integrally with the rotating shaft 8 via the sleeve 2.

[0046] In the static seal ring 5 and the rotary seal ring 3, the sliding surface S1 of the static seal ring 5 and the sliding surface S2 of the rotary seal ring 3 are in close contact and slide with each other via the spring 6 and the bellows 7 that axially bias the static seal ring 5. In addition, the sliding surface S2 of the rotary seal ring 3 is a flat surface, and no recessed portion such as a groove is provided on the flat surface.

[0047] like Figure 2 , 3 As shown in FIG. 1 , in the static seal ring 5, the base material B is formed of hard ceramic (silicon nitride, zirconium oxide, aluminum oxide, SiC, etc.), and a DLC (Diamond Like Carbon) film F is formed on the surface Ba facing the flat rotary seal ring 3. In this embodiment, a wave shape of substantially the same width is formed in an annular shape in the DLC film F, constituting the shoulder surface 9 of the sliding surface S1 in the entire circumferential direction. In addition, it is not limited to the DLC film, and a TiN (titanium nitride) film may also be formed. Furthermore, the DLC film may be formed on one surface of the sliding surface S2 of the rotary seal ring 3.

[0048] like Figure 2 As shown, a plurality of inner recesses 11 and a plurality of outer recesses 12 are arranged at equal intervals on the sliding surface S1 of the static seal ring 5 except the shoulder surface 9. That is, the sliding surface S1 is composed of the shoulder surface 9, the inner recesses 11 and the outer recesses 12, the shoulder surface 9 is the contact area of ​​the sliding surface S1, and the inner recesses 11 and the outer recesses 12 are the non-contact areas of the sliding surface S1.

[0049] The inner concave portion 11 is recessed in the circumferential direction more than the upper surface of the shoulder surface 9, and has a shape surrounded by a quadratic curve or a hyperbola when viewed from the axial direction, with the radial line D1 indicated by the dotted line extending in the radial direction of the sliding surface S1 as the reference. The inner concave portion 11 is divided into: an opening portion 11a, which is open to the inner diameter side of the static seal ring 5; a peripheral wall 11b, which serves as the peripheral edge of the inner diameter side of the shoulder surface 9; and a bottom wall 11c, which is substantially orthogonal to the peripheral wall 11b and extends to the inner diameter side and is parallel to the upper surface of the shoulder surface 9 (refer to Figure 3 The outermost diameter side of the inner recess 11 is referred to as the closed end 11d as the outer end. In addition, the circumferential dimension X1 of the inner diameter side boundary of the region of the inner recess 11 facing the sliding surface S2 of the rotary seal ring 3 (refer to Figure 2 (b) ) is greater than the axial dimension Y1 (see Figure 3 (a). )long (X1>Y1).

[0050] The outer recess 12 is recessed in the axial direction more than the upper surface of the shoulder surface 9, and has a shape surrounded by a quadratic curve or a hyperbola when viewed from the axial direction, with the radial line D2 indicated by the dashed line extending in the radial direction of the sliding surface S1 as a reference. The outer recess 12 is divided into: an opening 12a, which is open to the outer diameter side of the static seal ring 5; a peripheral wall 12b, which serves as the peripheral edge of the outer diameter side of the shoulder surface 9; and a bottom wall 12c, which is formed on the base material B (refer to FIG. 12c ) which is substantially orthogonal to the peripheral wall 12b and extends to the outer diameter side and is parallel to the upper surface of the shoulder surface 9. Figure 3 The innermost diameter side of the outer recess 12 is referred to as the closed end 12d as the inner end. In addition, the circumferential dimension X2 of the outer diameter side boundary of the region of the outer recess 12 facing the sliding surface S2 of the rotary seal ring 3 (refer to Figure 2 (b) ) is greater than the axial dimension Y2 (refer to Figure 3 (b). ) is longer (X2>Y2). In addition, the closed end 12d of the outer recess 12 is located closer to the inner diameter side than the closed end 11d of the inner recess 11, that is, the inner recess 11 and the outer recess 12 overlap in the circumferential direction.

[0051] In addition, refer to Figure 2 (a) The radial width of the sliding surface S1 of the static seal ring 5 is greater than that of the sliding surface S2 of the rotary seal ring 3 (see Figure 3 (a). ) width. Thus, when the rotary seal ring 3 rotates relatively, even if the rotary seal ring 3 temporarily deviates in the radial direction, the static seal ring 5 can slide in a state where the shoulder surface 9, the inner recess 11, and the outer recess 12 of the sliding surface S1 of the static seal ring 5 are located on the entire surface of the sliding surface S2 of the rotary seal ring 3.

[0052] Next, the operation of discharging the wear powder 10 generated by the wear between the sliding surfaces S1 and S2 will be described. The sliding surfaces S1 and S2 have a concave-convex shape at a microscopic level, such as Figure 4 As shown in (a), when the rotary seal ring 3 rotates relative to the static seal ring 5 in the direction of the arrow, the convex portion 13 of the shoulder surface 9 of the sliding surface S1 contacts the convex portion 15 of the sliding surface S2. In addition, the sliding surfaces S1 and S2 form a physicochemically stable (i.e., inactive) surface layer at the microscopic level. Figure 4 The surface layer is indicated by hatching.

[0053] Then, if Figure 4 (b) Figure 5As shown in (a), after the convex parts 13 and 15 come into contact, a part of the convex part 13 on one side (here, the rotary seal ring 3 side) is broken, and thus fine wear powder 10 may be generated. At this time, the broken part 14 of the convex part 13 becomes a state in which the inactive surface disappears, the deep part of the rotary seal ring 3 is exposed, and it is easy to combine with other materials (i.e., activated state). For example, when the rotary seal ring 3 is formed of SiC, the convex part 13 on the surface of the sliding surface S2 is broken, and thus the end face of the broken part becomes a state having a so-called bonding hand like Si-.

[0054] In addition, if Figure 4 (c) Figure 5 As shown in (b), the wear powder 10 flows in the direction of the arrow through the sealed liquid L as the rotary seal ring 3 rotates, from the shoulder surface 9 of the sliding surface S1 to the non-contact area (at Figure 5 After the outer concave portion 12 is moved, it moves toward the sealed liquid side along with the flow of the sealed liquid L and is discharged to the outside of the rotating seal ring 3 (refer to Figure 5 (c) to (e)). As a result, the wear powder 10 on the shoulder surface 9 is collected by the outer recess 12 and quickly discharged to the outside, so that the wear powder 10 can be prevented from being accumulated at the defective portion 14.

[0055] At this time, if Figure 4 As shown in (d), the defective portion 14 where a part of the convex portion 13 is defective and the active layer is exposed slides for a period of time in a state exposed to the sealed liquid L, thereby becoming substantially the same structure as the surface layer around the defective portion through thermal, mechanical and chemical effects, and deactivating. Therefore, even if the wear powder 10 floats on the shoulder surface 9, since the defective portion 14 is deactivated over time, it is difficult for the wear powder 10 to adhere to the defective portion 14. In addition, the same is true when the wear powder is generated in the DLC film F of the shoulder surface 9 of the sliding surface S1.

[0056] As described above, the sliding surface S1 of the static seal ring 5 is formed with: a shoulder surface 9 extending in the circumferential direction so as to be in contact with the opposite sliding surface S2; an inner recess 11 which is recessed in the axial direction and extends to the inner diameter side and is open to the inner diameter side; and an outer recess 12 which is recessed in the axial direction and extends to the outer diameter side and is open to the outer diameter side. Thus, at least the inner recess 11 and the outer recess 12 are arranged in the circumferential direction. Therefore, the wear powder 10 generated on the shoulder surface 9 as the rotary seal ring 3 and the static seal ring 5 rotate relative to each other moves with the relative rotation, and is recovered by the inner recess 11 or the outer recess 12 and is quickly discharged to the outside. Thus, the damage to the sliding surfaces S1 and S2 can be reduced.

[0057] In addition, the inner recess 11 and the outer recess 12 overlap in the circumferential direction, so the wear powder 10 lost on the shoulder surface 9 can be easily and reliably recovered by the inner recess 11 or the outer recess 12 as the rotary seal ring 3 and the static seal ring 5 rotate relative to each other.

[0058] In addition, the inner recesses 11 and the outer recesses 12 are arranged alternately and at equal intervals in the circumferential direction, so that the wear powder 10 lost on the shoulder surface 9 can be easily and reliably recovered by the inner recesses 11 or the outer recesses 12 as the rotary seal ring 3 and the static seal ring 5 rotate relative to each other.

[0059] Furthermore, since the inner recess 11 and the outer recess 12 are line-symmetrical shapes with respect to the respective radial lines D1 and D2 , the wear powder 10 can be reliably recovered in either rotation direction.

[0060] In addition, the inner recess 11 is formed so that its width becomes wider as it goes toward the inner diameter side, and the outer recess 12 is formed so that its width becomes wider as it goes toward the outer diameter side, so it is easy to discharge the wear powder 10 recovered in the inner recess 11 to the inner diameter side of the sliding surface S1, and it is easy to discharge the wear powder 10 recovered in the outer recess 12 to the outer diameter side of the sliding surface S2.

[0061] In addition, since the peripheral walls 11 b and 12 b of the inner recess 11 and the outer recess 12 are curved, the wear powder 10 collected in the inner recess 11 or the outer recess 12 can be easily discharged smoothly to the inner diameter side or the outer diameter side of the sliding surface S1 .

[0062] Furthermore, since the shoulder surface 9 is provided to extend in the entire circumferential direction, the sealing performance can be improved.

[0063] In addition, the circumferential dimensions X1 and X2 of the boundaries of the areas of the inner recess 11 and the outer recess 12 that are opposite to the sliding surface S2 of the rotating seal ring 3 are longer than their respective axial dimensions Y1 and Y2 (X1>Y1, X2>Y2), so it is easy to release the wear powder 10 recovered into the inner recess 11 or the outer recess 12 to the inner diameter side or the outer diameter side of the sliding surface S1.

[0064] In addition, since the shoulder surface 9 is formed of the DLC film F or the TiN film, the height of the shoulder surface 9 can be formed extremely low, and the friction coefficient generated between the rotary seal ring 3 and the static seal ring 5 can be easily reduced. In addition, since the inner concave portion 11 and the outer concave portion 12 of the sliding surface S1 are formed shallowly, it is possible to suppress the mixing of foreign matter from the outside.

[0065] Example 2

[0066] Next, refer to Figure 6 A mechanical seal according to Example 2 will be described. In addition, descriptions of the same structures as those of Example 1 will be omitted.

[0067] In the mechanical seal 101 of the second embodiment, Figure 6 As shown in FIG. 1 , a plurality of inner recesses 111 and a plurality of outer recesses 112 are arranged at equal intervals on the sliding surface S3 of the static seal ring 105 except for the shoulder surface 109. The inner recess 111 is in a shape surrounded by a substantially semicircle when viewed from the axial direction, with reference to the radial line D3 indicated by the dashed line extending in the radial direction of the sliding surface S3, and is divided into: an opening 111a, which is open to the inner diameter side of the static seal ring 105; an arc-shaped peripheral wall 111b, which forms the peripheral edge of the inner diameter side of the shoulder surface 109; and a bottom wall 111c, which is formed by the upper surface of the base material B that is substantially orthogonal to the peripheral wall 111b and extends to the inner diameter side and is parallel to the upper surface of the shoulder surface 109. The outermost diameter side of the inner recess 111 is referred to as a closed end 111d.

[0068] The outer recess 112 is in a shape surrounded by a semicircle when viewed from the axial direction, with the radial line D4 indicated by the dashed line extending in the radial direction of the sliding surface S3 as a reference, and is divided into: an opening 112a, which is open to the outer diameter side of the static seal ring 105; a peripheral wall 112b, which forms the outer diameter side peripheral edge of the shoulder surface 109; and a bottom wall 112c, which is formed by the upper surface of the base material B that is substantially orthogonal to the peripheral wall 112b and extends to the outer diameter side and is parallel to the upper surface of the shoulder surface 109. The outermost diameter side of the outer recess 112 is called a closed end 112d.

[0069] Similar to Example 1, the wear powder 10 generated by the wear between the sliding surfaces S3 and S2 flows in the rotation direction through the sealed liquid L as the rotating seal ring 3 rotates, moves from the shoulder surface 109 of the sliding surface S3 to the inner recess 111 or the outer recess 112, and is discharged to the outside of the rotating seal ring 3 along with the flow of the sealed liquid L.

[0070] In addition, the closed end 111d of the inner recess 111 and the closed end 112d of the outer recess 112 are arranged on substantially concentric circles. Thus, the closed end 111d of the inner recess 111 and the closed end 112d of the outer recess 112 are aligned in the circumferential direction, so that the wear powder 10 lost on the shoulder surface 109 can be easily reliably recovered by the inner recess 111 or the outer recess 112 as the rotary seal ring 3 and the static seal ring 105 rotate relative to each other.

[0071] Example 3

[0072] Next, refer to Figure 7 A mechanical seal according to Example 3 will be described. In addition, descriptions of the same structures as those of Example 1 will be omitted.

[0073] In the mechanical seal 201 of the third embodiment, Figure 7As shown in the figure, a plurality of inner recesses 211 and a plurality of outer recesses 212 are arranged circumferentially at equal intervals on the sliding surface S4 of the static seal ring 205 except for the shoulder surface 209. The inner recess 211 is in a shape that is surrounded by a generally rectangular shape in the axial direction based on the radial line D5 indicated by the dashed line extending in the radial direction of the sliding surface S4, and the inner recess 211 is divided into: an opening 211a that is open to the inner diameter side of the static seal ring 205; peripheral walls 211b, 211b', 211b", which form the inner diameter side periphery of the shoulder surface 209; and a bottom wall 211c, which is formed by the upper surface of the base material B that is generally orthogonal to the peripheral walls 211b, 211b', 211b", and extends to the inner diameter side and is parallel to the upper surface of the shoulder surface 209. The outermost diameter side of the inner recess 211 is called a closed end 211d.

[0074] The outer recess 212 is in a shape enclosed in an axial rectangular shape based on the radial line D6 indicated by the dot-dash line extending radially along the sliding surface S4, and is divided into: an opening 212a, which is open to the outer diameter side of the static seal ring 205; peripheral walls 212b, 212b', 212b", which form the outer diameter side peripheral edge of the shoulder surface 209; and a bottom wall 212c, which is formed by the upper surface of the base material B that is approximately orthogonal to the peripheral walls 212b, 212b', 212b", and extends to the outer diameter side and is parallel to the upper surface of the shoulder surface 209. The innermost diameter side of the outer recess 212 is called a closed end 212d.

[0075] Similar to Example 1, the wear powder 10 generated by the wear between the sliding surfaces S4 and S2 flows in the rotation direction through the sealed liquid L as the rotating seal ring 3 rotates, moves from the shoulder surface 209 of the sliding surface S4 to the inner recess 211 or the outer recess 212, and is discharged to the outside of the rotating seal ring 3 along with the flow of the sealed liquid L.

[0076] In addition, the closed end 211d of the inner recess 211 and the closed end 212d of the outer recess 212 are arranged on substantially concentric circles. Thus, the closed end 211d of the inner recess 211 and the closed end 212d of the outer recess 212 are aligned in the circumferential direction, so that the wear powder 10 lost on the shoulder surface 209 can be easily reliably recovered by the inner recess 211 or the outer recess 212 as the rotary seal ring 3 and the static seal ring 205 rotate relative to each other.

[0077] Example 4

[0078] Next, refer to Figure 8 A mechanical seal according to Example 4 will be described. In addition, description of the same structure as that of the above-mentioned Example 1 will be omitted.

[0079] In the mechanical seal 301 of the fourth embodiment, Figure 8As shown in FIG. 1 , the radial width of the sliding surface S5 of the static seal ring 305 is substantially the same as the radial width of the sliding surface S2 of the rotary seal ring 3, and a plurality of inner recesses 311 and a plurality of outer recesses 312 are arranged circumferentially at equal intervals on the portion of the sliding surface S5 other than the shoulder surface 309. The inner recess 311 is in a shape that is surrounded by a substantially rectangular shape in the axial direction based on the radial line D7 indicated by the dashed line extending in the radial direction of the sliding surface S5, and the inner recess 311 is divided into: an opening 311a that is open to the inner diameter side of the static seal ring 305; peripheral walls 311b, 311b', 311b", which form the inner diameter side peripheral edge of the shoulder surface 309; and a bottom wall 311c that is formed by the upper surface of the base material B that is substantially orthogonal to the peripheral walls 311b, 311b', 311b", and extends to the inner diameter side and is parallel to the upper surface of the shoulder surface 309. The outermost diameter side of the inner recessed portion 311 is referred to as a closed end 311 d .

[0080] The outer recess 312 is in a shape enclosed in an axial rectangular shape based on the radial line D8 indicated by the dotted line extending radially along the sliding surface S5, and is divided into: an opening portion 312a, which is open to the outer diameter side of the static seal ring 305; peripheral walls 312b, 312b', 312b", which form the outer diameter side peripheral edge of the shoulder surface 309; and a bottom wall 312c, which is formed by the upper surface of the base material B that is approximately orthogonal to the peripheral walls 312b, 312b', 312b", and extends to the outer diameter side and is parallel to the upper surface of the shoulder surface 309. The innermost diameter side of the outer recess 312 is called a closed end 312d.

[0081] Similar to Example 1, the wear powder 10 generated by the wear between the sliding surfaces S5 and S2 flows in the rotation direction through the sealed liquid L as the rotating seal ring 3 rotates, moves from the shoulder surface 309 of the sliding surface S5 to the inner recess 311 or the outer recess 312, and is then discharged to the outside of the rotating seal ring 3 along with the flow of the sealed liquid L.

[0082] In addition, the closed end 311d of the inner concave portion 311 and the closed end 312d of the outer concave portion 312 are arranged on substantially concentric circles. Thus, the closed end 311d of the inner concave portion 311 and the closed end 312d of the outer concave portion 312 are aligned in the circumferential direction, so that the wear powder 10 lost on the shoulder surface 309 can be easily reliably recovered by the inner concave portion 311 or the outer concave portion 312 as the rotary seal ring 3 and the static seal ring 305 rotate relative to each other.

[0083] As mentioned above, although the embodiments of the present invention have been described with reference to the drawings, the specific configuration 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.

[0084] For example, the case where the shoulder surface is formed by providing the DLC film F on the sliding surface has been described, but the present invention is not limited to this, and the shoulder surface may be formed by cutting the sliding surface to form a recessed portion.

[0085] In addition, the case where the shoulder surface, the inner recess and the outer recess are formed on the static seal ring has been described, but the present invention is not limited thereto. The shoulder surface, the inner recess and the outer recess may be formed on one of the rotary seal ring and the static seal ring, preferably on one of the rotary seal ring and the static seal ring. In this case, the relative positions of the shoulder surface, the inner recess and the outer recess are not offset, so that the structure is simple and reliable sealing can be performed between the inner diameter side and the outer diameter side.

[0086] In addition, the case where the inner concave portion 11 and the outer concave portion 12 overlap in the circumferential direction in Example 1, and the closed end of the inner concave portion and the closed end of the outer concave portion coincide in the circumferential direction in Examples 2 to 4 is described, but the present invention is not limited thereto, and the closed end of the inner concave portion and the closed end of the outer concave portion may coincide in the circumferential direction in Example 1, and the closed end of the inner concave portion and the closed end of the outer concave portion may overlap in the circumferential direction in Examples 2 to 4. Furthermore, in Examples 1 to 4, the inner concave portion and the outer concave portion may not overlap in the circumferential direction, and the closed ends may not coincide with each other.

[0087] In addition, the shapes of the inner recess and the outer recess are not limited to the shapes listed in the embodiments, and for example, they may be substantially triangular when viewed from the axial direction.

[0088] In addition, the number of inner and outer recesses is not limited to Figure 2 , Figures 6 to 8 The number shown can be any number.

[0089] Furthermore, although the case where the plurality of inner recesses and the plurality of outer recesses are arranged at equal intervals in the circumferential direction has been described, the present invention is not limited thereto and the plurality of inner recesses and the plurality of outer recesses may not be arranged at equal intervals in the circumferential direction.

[0090] In addition, the case where multiple inner recesses and multiple outer recesses are alternately arranged in the circumferential direction is described, but it is not limited to this. For example, inner recesses, inner recesses, outer recesses, outer recesses... may be arranged in sequence in the circumferential direction.

[0091] In addition, grooves for generating positive pressure or negative pressure and small recesses for improving lubricity may be provided on the shoulder surface.

[0092] Explanation of symbols

[0093] 1: Mechanical seal; 2: Sleeve; 3: Rotating seal ring (seal ring); 4: Housing; 5: Static seal ring (seal ring); 6: Spring; 7: Bellows; 8: Rotating shaft; 9: Shoulder surface; 10: Wear powder; 11: Inner recess; 11b: Peripheral wall (peripheral edge); 11d: Closed end (outer end); 12: Outer recess; 12b: Peripheral wall (peripheral edge); 12d: Closed end (inner end); 14: Defective part; 101: Mechanical seal; 105: Static seal ring; 109: Shoulder surface; 111: Inner recess; 112: Outer recess; 12b: Peripheral wall (peripheral edge); 12d: Closed end (inner end); 14: Defective part; 101: Mechanical seal; 105: Static seal ring; 109: Shoulder surface; 111: Inner recess; 112: Outer recess Recess; 201: mechanical seal; 205: static seal ring; 309: shoulder surface; 311: inner recess; 312: outer recess; 401: mechanical seal; 405: static seal ring; 409: shoulder surface; 411: inner recess; 412: outer recess; A: atmosphere side (low-pressure side); B: substrate; Ba: opposite surface; D1-D8: radial line; F: DLC film; L: sealed liquid; M: sealed liquid side (high-pressure side); S1-S5: sliding surface; X1, X2: circumferential dimensions; Y1, Y2: axial dimensions.

Claims

1. A sliding component comprising a pair of sealing rings arranged to rotate relative to each other, wherein: The sealing ring has a sliding surface formed thereon with: a shoulder surface extending in the circumferential direction capable of contacting the opposing sliding surface; an inner recessed portion recessed in the axial direction and extending to the inner diameter side and open to the inner diameter side; and an outer recessed portion recessed in the axial direction and extending to the outer diameter side and open to the outer diameter side; and Each inner concave portion and each outer concave portion respectively have a line-symmetrical shape with respect to a radial line and a substantially rectangular shape in a plan view.

2. The sliding component according to claim 1, wherein The inner recess and the outer recess overlap in the circumferential direction.

3. The sliding component according to claim 1, wherein The outer end of the inner recess and the inner end of the outer recess coincide with each other in the circumferential direction.

4. The sliding component according to any one of claims 1 to 3, wherein The inner recessed portions and the outer recessed portions are arranged alternately and at equal intervals in the circumferential direction.

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