Sliding part

Abstract

The present invention provides a sliding component capable of reducing damage to a sliding surface. The sliding component (1) comprises a pair of sealing rings (3, 5) arranged to rotate relative to each other, wherein a shoulder surface (9) extending in a circumferential direction capable of contacting an opposing sliding surface (S2) is formed on the sliding surface (S1) of the sealing ring (5); an inner recess (11) recessed in the axial direction and extending toward the inner diameter side and opening toward the inner diameter side; and an outer recess (12) recessed in the axial direction and extending toward the outer diameter side and opening toward the outer diameter side.

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 fields. Background Art

[0002] Sliding components used in shaft seals and bearings require smooth sliding surfaces, thereby reducing durability and energy loss. For example, mechanical seals, used as shaft seals to prevent leakage of sealed fluids, include a pair of annular seal rings that rotate relative to each other and slide against each other's sliding surfaces. Patent Document 1, as an example of such a mechanical seal, discloses a seal comprising a static seal ring and a rotating seal ring, with multiple small recesses formed on the sliding surface of one of the seal rings.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2017-207209 (page 5, Figure 1 ) Summary of the Invention

[0006] Problems to be solved by the invention

[0007] When a sliding part such as Patent Document 1 is in use, the sealed fluid is retained in the small recess. As a result, the sealed fluid is interposed between the sliding surfaces and reduces the friction generated between the sliding surfaces, making each sliding surface less susceptible to wear. In addition, the sliding surface is microscopically concave and convex, and a portion of the convex portion 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 portion of the partially defective convex portion becomes the base of the sliding part and becomes more active than the surface layer and easily combines with other components, such as the defective wear powder. In addition, since the wear powder recovered in the small recess can flow out of the small recess again to between the sliding surfaces due to the relative movement between the sliding parts, it is easy to remain between the sliding surfaces, causing accumulation areas to form on the sliding surfaces of other parts, thereby making the sliding surfaces easily damaged.

[0008] 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.

[0009] Means for solving problems

[0010] In order to solve the above-mentioned problems, the sliding component of the present invention has a pair of seal rings arranged to rotate relative to each other.

[0011] 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.

[0012] Thus, at least one inner recess and one outer recess are arranged circumferentially. Therefore, wear powder generated on the shoulder surface during the relative rotation of the pair of seal rings moves with the relative rotation, is collected by the inner or outer recess, and is quickly discharged to the outside. This reduces damage to the sliding surface.

[0013] The inner recessed portion and the outer recessed portion may overlap in the circumferential direction.

[0014] Thus, as the pair of seal rings rotate relative to each other, wear powder lost on the shoulder surface can be easily and reliably recovered by the inner recess or the outer recess.

[0015] The outer end of the inner recess and the inner end of the outer recess may coincide with each other in the circumferential direction.

[0016] Thus, as the pair of seal rings rotate relative to each other, wear powder lost on the shoulder surface can be easily and reliably recovered by the inner recess or the outer recess.

[0017] The inner recessed portions and the outer recessed portions may be arranged alternately and at equal intervals in the circumferential direction.

[0018] Thus, as the pair of seal rings rotate relative to each other, wear powder lost on the shoulder surface can be easily and reliably recovered by the inner recess or the outer recess.

[0019] Alternatively, the inner concave portion and the outer concave portion may be line-symmetrical shapes with respect to their respective radial lines.

[0020] As a result, wear powder can be reliably recovered regardless of the rotation direction.

[0021] 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.

[0022] This makes it easier to discharge the wear powder collected in the inner recess to the inner diameter side of the sliding surface, and easier to discharge the wear powder collected in the outer recess to the outer diameter side of the sliding surface.

[0023] The inner concave portion and the outer concave portion may each have a curved peripheral edge.

[0024] This facilitates smooth release of the wear powder recovered in the inner or outer recessed portions toward the inner or outer diameter side of the sliding surface.

[0025] The shoulder surface, the inner recess, and the outer recess may be formed on one of the seal rings.

[0026] Thus, the relative positions of the shoulder surface, the inner recess, and the outer recess are not shifted, 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.

[0027] Alternatively, the shoulder surface may extend in the entire circumferential direction.

[0028] Thereby, the sealing performance can be improved.

[0029] The inner and outer recessed portions may have circumferential dimensions longer than their respective axial dimensions.

[0030] This makes it easier to release the wear powder recovered in the inner or outer recessed portion toward the inner or outer diameter side of the sliding surface.

[0031] The shoulder surface may be formed of a DLC (Diamond Like Carbon) film or a TiN film.

[0032] 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

[0033] Figure 1 is a longitudinal sectional view showing an example of a mechanical seal in Embodiment 1 of the present invention;

[0034] 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 illustrating a region of the sliding surface of the static seal ring that faces the sliding surface of the rotating seal ring.

[0035] Figure 3 (a) Yes Figure 2 (a) is the α-α cross-section, (b) is Figure 2 (a) is the β-β cross-section, (c) is Figure 2 (a) γ-γ cross-section;

[0036] Figure 4 (a) to (d) are schematic diagrams showing the state of the sliding surface after grinding at a microscopic level;

[0037] Figure 5 (a) to (e) are schematic diagrams illustrating the discharge of wear powder;

[0038] Figure 6(a) is a diagram showing the sliding surface of a static seal ring according to a second embodiment of the present invention as viewed from the axial direction; (b) is a diagram illustrating a region of the sliding surface of the static seal ring according to the second embodiment of the present invention that faces the sliding surface of the rotary seal ring;

[0039] Figure 7 (a) is a diagram showing the sliding surface of a static seal ring according to Example 3 of the present invention as viewed from the axial direction; (b) is a diagram illustrating a region of the sliding surface of the static seal ring according to Example 3 of the present invention that faces the sliding surface of the rotary seal ring;

[0040] 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 illustrating a region of the sliding surface of the static seal ring in Example 4 of the present invention that faces the sliding surface of the rotary seal ring. DETAILED DESCRIPTION

[0041] Hereinafter, modes for implementing the sliding member of the present invention will be described based on examples.

[0042] Example 1

[0043] Reference Figures 1 to 5 The sliding component of Example 1 will be described. In this example, the sliding component is a mechanical seal. The outer diameter side of the seal ring constituting the mechanical seal is assumed to be the sealed liquid side (high-pressure side), which serves as the sealed fluid side, and the inner diameter side is assumed to be the atmospheric side (low-pressure side), which serves as the leakage side. For ease of explanation, the recessed portions formed on the sliding surface are sometimes indicated by dots in the drawings.

[0044] 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 mounted 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 arranged on the side of the rotating shaft 8 that drives the pump impeller (not shown) on the high-pressure fluid side in a state that can rotate integrally with the rotating shaft 8 via the sleeve 2.

[0045] 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 slide in close contact with each other via the spring 6 and the bellows 7 that axially bias the static seal ring 5. Furthermore, the sliding surface S2 of the rotary seal ring 3 is a flat surface without any recessed portions such as grooves.

[0046] like Figure 2 、 3 As shown, in the static seal ring 5, the base material B is formed of a hard ceramic (such as silicon nitride, zirconium oxide, aluminum oxide, or SiC). A DLC (Diamond-Like Carbon) film F is formed on the surface Ba facing the flat rotating seal ring 3. In this embodiment, a wave-like shape of approximately uniform width is formed in the DLC film F in an annular shape, forming the shoulder surface 9 of the sliding surface S1 along the entire circumference. Furthermore, the film is not limited to a DLC film; a TiN (titanium nitride) film can also be formed. Furthermore, the DLC film can also be formed on a single surface of the sliding surface S2 of the rotating seal ring 3.

[0047] like Figure 2 As shown, multiple inner recesses 11 and multiple outer recesses 12 are arranged at equal intervals on the circumferential direction of the sliding surface S1 of the static seal ring 5, excluding the shoulder surface 9. In other words, 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.

[0048] The inner concave portion 11 is recessed in the circumferential direction relative to 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 a reference. The inner concave portion 11 is divided into: an opening 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 perpendicular 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 concave portion 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 concave portion 11 facing the sliding surface S2 of the rotary seal ring 3 (refer to Figure 2 (b) The axial dimension Y1 from the upper surface of the shoulder surface 9 to the bottom wall 11c (see Figure 3 (a). )long (X1>Y1).

[0049] The outer concave portion 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 dotted line extending in the radial direction of the sliding surface S1 as the reference. The outer concave portion 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. 1 ) 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 3The 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) The axial dimension Y2 from the upper surface of the shoulder surface 9 to the bottom wall 12c (see Figure 3 (b) Length (X2>Y2). In addition, the closed end 12d of the outer recess 12 is located further inward 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.

[0050] 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). ) Wide. Thus, even if the rotating seal ring 3 temporarily deviates in the radial direction during relative rotation, the static seal ring 5 can slide with the shoulder surface 9, the inner recess 11, and the outer recess 12 of the sliding surface S1 located entirely on the sliding surface S2 of the rotating seal ring 3.

[0051] 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.

[0052] Then, if Figure 4 (b) Figure 5 As shown in (a), after the convex portions 13 and 15 come into contact, a portion of the convex portion 13 on one side (here, the rotary seal ring 3 side) is partially broken, which may generate fine wear powder 10. At this time, the broken portion 14 of the convex portion 13 becomes inactive, the surface disappears, the deep portion of the rotary seal ring 3 is exposed, and it is easy to bond with other materials (i.e., it is activated). For example, when the rotary seal ring 3 is formed of SiC, the convex portion 13 on the surface of the sliding surface S2 is broken, and the end surface of the broken portion becomes a state with so-called bonding hands like Si-.

[0053] 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 5After 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, thereby preventing the wear powder 10 from accumulating at the defective portion 14.

[0054] At this time, if Figure 4 As shown in (d), a portion of the protrusion 13 is partially lost, exposing a defective portion 14 of the active layer. While exposed to the sealed liquid L, the active layer slides for a period of time. Through thermal, mechanical, and chemical reactions, the active layer becomes substantially identical to the surface layer surrounding the defective portion, and the active layer becomes inactive. Therefore, even if wear powder 10 floats on the shoulder surface 9, the defective portion 14 becomes inactive over time, making it difficult for the wear powder 10 to adhere to the defective portion 14. The same applies to the case where wear powder is generated in the DLC film F on the shoulder surface 9 of the sliding surface S1.

[0055] As described above, the sliding surface S1 of the static seal ring 5 is formed with: a shoulder surface 9 extending circumferentially to contact the opposing sliding surface S2; an inner recess 11 that is axially recessed, extends radially inward, and is open radially inward; and an outer recess 12 that is axially recessed, extends radially outward, and is open radially outward. With at least the inner recess 11 and the outer recess 12 arranged circumferentially, wear powder 10 generated on the shoulder surface 9 during the relative rotation of the rotating seal ring 3 and the static seal ring 5 moves with the relative rotation and is recovered by the inner recess 11 or the outer recess 12, quickly discharged to the outside. This reduces damage to the sliding surfaces S1 and S2.

[0056] Furthermore, the inner recess 11 and the outer recess 12 overlap in the circumferential direction, so that the wear powder 10 lost on the shoulder surface 9 can be 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.

[0057] 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.

[0058] Furthermore, the inner recess 11 and the outer recess 12 are line-symmetrical with respect to the respective radial lines D1 and D2 , and thus the wear powder 10 can be reliably recovered regardless of the rotation direction.

[0059] 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 that 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.

[0060] Furthermore, since the peripheral walls 11 b and 12 b of the inner and outer recesses 11 and 12 are curved, the wear powder 10 collected in the inner and outer recesses 11 and 12 can be easily discharged smoothly to the inner or outer diameter side of the sliding surface S1 .

[0061] Furthermore, since the shoulder surface 9 extends over the entire circumferential direction, the sealing performance can be improved.

[0062] In addition, the circumferential dimensions X1 and X2 of the boundaries of the areas of the inner recess 11 and the outer recess 12 facing the sliding surface S2 of the rotary seal ring 3 are longer than their respective axial dimensions Y1 and Y2 (X1>Y1, X2>Y2), so that the wear powder 10 recovered in the inner recess 11 or the outer recess 12 is easily released to the inner diameter side or the outer diameter side of the sliding surface S1.

[0063] Furthermore, 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 extremely low, and the coefficient of friction generated between the rotary seal ring 3 and the static seal ring 5 can be easily reduced. Furthermore, since the inner concave portion 11 and the outer concave portion 12 of the sliding surface S1 are formed shallowly, the intrusion of foreign matter from the outside can be suppressed.

[0064] Example 2

[0065] Next, refer to Figure 6 A mechanical seal according to Example 2 will be described. Explanations of the same or overlapping configurations as those of Example 1 will be omitted.

[0066] In the mechanical seal 101 of the second embodiment, Figure 6 As shown, multiple inner recesses 111 and outer recesses 112 are circumferentially and evenly spaced apart on the sliding surface S3 of the static seal ring 105, excluding the shoulder surface 109. The inner recesses 111 are shaped as a substantially semicircle, as viewed axially, with reference to a radial line D3, indicated by a dashed line, extending radially along the sliding surface S3. The inner recesses 111 are divided into an opening 111a, which opens toward the inner diameter of the static seal ring 105; an arcuate peripheral wall 111b, which forms the inner diameter edge of the shoulder surface 109; and a bottom wall 111c, formed by the upper surface of the base material B, extending radially inwardly and approximately orthogonally to the peripheral wall 111b and parallel to the upper surface of the shoulder surface 109. The outermost radial end of the inner recess 111 is referred to as the closed end 111d.

[0067] The outer recess 112 has a shape that is surrounded by a semicircle when viewed in the axial direction, with reference to a radial line D4 indicated by a dashed line extending radially along the sliding surface S3. The outer recess 112 is divided into an opening 112a that opens toward the outer diameter of the static seal ring 105; a peripheral wall 112b that forms the outer diameter peripheral edge of the shoulder surface 109; and a bottom wall 112c formed by the upper surface of the base material B, extending radially outward and substantially orthogonal to the peripheral wall 112b and parallel to the upper surface of the shoulder surface 109. The outermost radial side of the outer recess 112 is referred to as a closed end 112d.

[0068] 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 then discharged to the outside of the rotating seal ring 3 along with the flow of the sealed liquid L.

[0069] Furthermore, 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. As a result, the closed ends 111d, 112d of the inner recess 111 and 112 are aligned in the circumferential direction. Therefore, wear powder 10 that is lost on the shoulder surface 109 can be reliably recovered by the inner recess 111 or the outer recess 112 as the rotating seal ring 3 and the static seal ring 105 rotate relative to each other.

[0070] Example 3

[0071] Next, refer to Figure 7 A mechanical seal according to Example 3 will be described. The description of the same structure as that of Example 1 will be omitted.

[0072] In the mechanical seal 201 of the third embodiment, Figure 7 As shown, multiple inner recesses 211 and outer recesses 212 are circumferentially and evenly spaced apart on the sliding surface S4 of the static seal ring 205, excluding the shoulder surface 209. The inner recesses 211 are axially roughly rectangular, defined by a radial line D5 (shown as a dashed line) extending radially along the sliding surface S4. The inner recesses 211 are divided into an opening 211a, which opens toward the inner diameter of the static seal ring 205; peripheral walls 211b, 211b', and 211b" that form the inner diameter edge of the shoulder surface 209; and a bottom wall 211c formed by the upper surface of the base material B, extending radially inwardly and approximately orthogonally to the peripheral walls 211b, 211b', and 211b" and parallel to the upper surface of the shoulder surface 209. The outermost radial side of the inner recess 211 is referred to as the closed end 211d.

[0073] The outer recess 212 is shaped like an axial rectangle with respect to a radial line D6 indicated by a dashed line extending radially along the sliding surface S4. The outer recess 212 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, which is substantially orthogonal to the peripheral walls 212b, 212b', 212b", and extends toward 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 referred to as a closed end 212d.

[0074] 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 then discharged to the outside of the rotating seal ring 3 along with the flow of the sealed liquid L.

[0075] Furthermore, 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. As a result, 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. Therefore, wear powder 10 that is lost on the shoulder surface 209 can be reliably recovered by the inner recess 211 or the outer recess 212 as the rotating seal ring 3 and the static seal ring 205 rotate relative to each other.

[0076] Example 4

[0077] Next, refer to Figure 8 A mechanical seal according to Example 4 will be described. The description of the same structure as that of Example 1 will be omitted.

[0078] In the mechanical seal 301 of the fourth embodiment, Figure 8 As shown, 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. Multiple inner recesses 311 and multiple outer recesses 312 are arranged circumferentially and evenly spaced on the sliding surface S5, excluding the shoulder surface 309. The inner recesses 311 are shaped to form a generally rectangular shape in the axial direction, with reference to a radial line D7, indicated by a dashed line, extending radially along the sliding surface S5. The inner recesses 311 are divided into an opening 311a, which opens toward the inner diameter of the static seal ring 305; peripheral walls 311b, 311b', and 311b" that form the inner diameter peripheral edge of the shoulder surface 309; and a bottom wall 311c formed by the upper surface of the base material B, extending radially inwardly and substantially orthogonally to the peripheral walls 311b, 311b', and 311b" and parallel to the upper surface of the shoulder surface 309. The outermost radial side of the inner recess 311 is referred to as a closed end 311 d .

[0079] The outer recess 312 is shaped like an axial rectangle, with the radial line D8 indicated by the dashed line extending radially along the sliding surface S5 as a reference. The outer recess 312 is divided into: an opening 312a, which is open to the outer diameter side of the static seal ring 305; peripheral walls 312b, 312b', and 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, which is approximately orthogonal to the peripheral walls 312b, 312b', and 312b", extends toward 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 referred to as the closed end 312d.

[0080] 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.

[0081] Furthermore, the closed end 311d of the inner recess 311 and the closed end 312d of the outer recess 312 are arranged on substantially concentric circles. As a result, the closed end 311d of the inner recess 311 and the closed end 312d of the outer recess 312 are aligned in the circumferential direction. Therefore, wear powder 10 that is lost on the shoulder surface 309 can be reliably recovered by the inner recess 311 or the outer recess 312 as the rotary seal ring 3 and the static seal ring 305 rotate relative to each other.

[0082] While the embodiments of the present invention have been described above with reference to the drawings, the specific configuration is not limited to these embodiments, and any changes or additions made without departing from the gist of the present invention are also encompassed by the present invention.

[0083] 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 thereto. The shoulder surface may be formed by forming a recessed portion by cutting the sliding surface.

[0084] Furthermore, while the shoulder surface, inner recess, and outer recess are described as being formed on the static seal ring, this is not limiting. Alternatively, the shoulder surface, inner recess, and outer recess may be formed on either the rotating seal ring or the static seal ring, preferably on either the rotating seal ring or the static seal ring. In this case, the relative positions of the shoulder surface, inner recess, and outer recess are not offset, resulting in a simple structure and reliable sealing between the inner and outer diameter sides.

[0085] In addition, in Example 1, the inner recess 11 and the outer recess 12 overlap in the circumferential direction, and in Examples 2 to 4, the closed ends of the inner recess and the closed ends of the outer recess coincide in the circumferential direction. However, the present invention is not limited to this. In Example 1, the closed ends of the inner recess and the closed ends of the outer recess may coincide in the circumferential direction, and in Examples 2 to 4, the closed ends of the inner recess and the closed ends of the outer recess may overlap in the circumferential direction. Furthermore, in Examples 1 to 4, the inner recess and the outer recess may not overlap in the circumferential direction, and their closed ends may not coincide with each other.

[0086] In addition, the shapes of the inner concave portion and the outer concave portion are not limited to the shapes listed in the respective embodiments, and for example, they may be substantially triangular when viewed from the axial direction.

[0087] 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.

[0088] 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 they may not be arranged at equal intervals in the circumferential direction.

[0089] In addition, the case where multiple inner recesses and multiple outer recesses are alternately arranged in the circumferential direction is described, but this is not limited to this. For example, inner recesses, inner recesses, outer recesses, outer recesses... may be arranged in sequence in the circumferential direction.

[0090] In addition, grooves for generating positive and negative pressures and small recesses for improving lubricity may be provided on the shoulder surface.

[0091] Explanation of symbols

[0092] 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 Recess; 201: Mechanical seal; 205: Static sealing ring; 309: Shoulder surface; 311: Inner recess; 312: Outer recess; 401: Mechanical seal; 405: Static sealing ring; 409: Shoulder surface; 411: Inner recess; 412: Outer recess; A: Atmosphere side (low-pressure side); B: Substrate; Ba: Opposite surface; D1-D8: Radial lines; F: DLC film; L: Sealed liquid; M: Sealed liquid side (high-pressure side); S1-S5: Sliding surfaces; 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 a serpentine manner in the circumferential direction so as to be in contact with the opposing sliding surface when viewed from the axial direction; an inner recessed portion recessed in the axial direction and extending toward the inner diameter side and open toward the inner diameter side; and an outer recessed portion recessed in the axial direction and extending toward the outer diameter side and open toward the outer diameter side; Each of the inner recesses has a circumferential width that increases toward the inner diameter side, so that the inner recesses extend in the clockwise direction and the counterclockwise direction relative to a radial line passing through the radially outermost end points of the inner recesses; Each of the outer recesses has a circumferential width that increases toward the outer diameter side, so that the outer recess extends in the clockwise direction and the counterclockwise direction relative to a radial line passing through the radially innermost end point of the outer recess; Each inner recess and each outer recess is defined by a peripheral edge that is continuously curved in the circumferential direction of the shoulder surface.

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 claim 1 or 2, wherein: The inner recessed portions and the outer recessed portions are arranged alternately and at equal intervals in the circumferential direction.

5. The sliding component according to claim 1 or 2, wherein The inner concave portion and the outer concave portion are line-symmetrical shapes with respect to their respective radial lines.

6. The sliding component according to claim 1 or 2, wherein: The inner concave portion and the outer concave portion each have a curved periphery.

7. The sliding component according to claim 1 or 2, wherein: The shoulder surface, the inner recess, and the outer recess are formed on one of the seal rings.

Images