Sliding parts

Abstract

Provided is a sliding component capable of efficiently utilizing a liquid that is supplied between sliding surfaces and maintaining high lubricity over a long period of time.　On the inner diameter side or the outer diameter side of at least one of a pair of sliding surfaces S3 and S6 of a sliding component, an annular depression 10 that opens in the radial direction along the entire circumference is formed. On at least one of the pair of sliding surfaces S3 and S6, supply grooves 11 that are in communication with the annular depression 10 and that extend in the radial direction of the sliding surfaces S3 and S6 are formed.

Description

[Technical field]

[0001] The present invention relates to a sliding part that rotates relative to another sliding part, for example, a sliding part used in a shaft sealing device that seals a rotating shaft of a rotating machine in an automobile, general industrial machine, or other sealing field, or a sliding part used in a bearing of a machine in an automobile, general industrial machine, or other bearing field. [Background technology]

[0002] Conventionally, a lubricant has been applied between the sliding surfaces of a pair of annular bodies constituting sliding parts that rotate relative to each other to reduce friction. However, the lubricant applied between the sliding surfaces is pushed out from between the sliding surfaces by the relative rotation of the annular bodies and gradually decreases, which causes a problem that lubrication cannot be maintained for a long period of time.

[0003] For example, a mechanical seal (see Patent Document 1, for example) having a stationary seal ring and a rotating seal ring as an annular body configured to rotate relative to one another and have flat end faces that slide against each other is known as a sliding part used in a shaft sealing device that seals the rotating shaft of a rotary machine such as a pump or a turbine and prevents leakage of the sealed fluid. The stationary seal ring is fixed to a housing. The rotating seal ring is fixed to a rotary shaft and rotates together with the rotary shaft. It is particularly important for such mechanical seals to maintain lubricity over the long term in order to prevent wear on the sliding surfaces while maintaining sealing performance.

[0004] Mechanical seals can use the fluid for lubrication by infiltrating the liquid between the sliding surfaces if the sealed fluid or the leaking fluid is a liquid such as oil. However, if the sealed fluid is a gas and the fluid in the leaking space is also a gas, the lubricant applied between the sliding surfaces due to the relative rotation of the annular bodies is pushed out of the gap between the sliding surfaces over time, and good lubrication cannot be maintained for a long period of time. Therefore, when both the sealed fluid and the fluid in the leaking space are gas, attempts are being made to maintain lubrication by supplying the liquid between the sliding surfaces by dripping a small amount of liquid as a lubricant. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2017-53423 A (page 4, figure 1) Summary of the Invention [Problem to be solved by the invention]

[0006] However, liquid supplied by dripping onto either the inner or outer edge of the sliding surface is difficult to guide toward the radial center of the sliding surface through the extremely small gap between the sliding surfaces when the pair of annular bodies rotate relative to one another. In addition, the relative rotation of the pair of annular bodies tends to cause the lubricant to be splashed toward the inner or outer side, so that the supplied liquid does not effectively contribute to improving lubricity, and high lubricity cannot be maintained over a long period of time.

[0007] The present invention has been made in light of these problems, and has an object to provide a sliding component that can efficiently utilize the liquid supplied between the sliding surfaces and maintain high lubrication properties for a long period of time. [Means for solving the problem]

[0008] In order to solve the above problems, the sliding component of the present invention comprises: A sliding component consisting of a pair of annular bodies arranged opposite to each other at a position where the rotating machine rotates relative to each other when the rotating machine is driven, An annular recess that opens radially around the entire circumference is formed on the inner diameter side or outer diameter side of at least one of a pair of sliding surfaces of the sliding part, and a supply groove that communicates with the annular recess and extends radially of the sliding surface is formed in at least one of the pair of sliding surfaces. According to this, since the annular recess is formed so as to be connected to the supply groove and open in the radial direction, the annular recess can easily take in liquid, and a large amount of liquid can be held in the annular recess and the supply groove, so that the liquid can be efficiently introduced between the sliding surfaces. In this way, the liquid supplied between the sliding surfaces can be efficiently utilized to maintain high lubricity for a long period of time.

[0009] A dynamic pressure generating groove may be formed which communicates with the supply groove and extends in a circumferential direction in which the opposing annular bodies rotate relative to one another. According to this, the liquid is guided from the supply groove to the dynamic pressure generating groove portion by the relative rotation of the annular body, dynamic pressure is generated at the end of the dynamic pressure generating groove portion, and this dynamic pressure separates the sliding surfaces to form a liquid film, improving lubrication. Furthermore, since the liquid is guided from the supply groove to the dynamic pressure generating groove portion, the liquid is easily drawn from the annular recess toward the supply groove.

[0010] The supply groove may be connected to a terminal end of the supply groove, the terminal end being connected to a single annular groove extending in the circumferential direction. With this, the liquid is collected from the terminal end of the supply groove into the annular groove and circulated in the circumferential direction, thereby making it possible to suppress discharge of the liquid.

[0011] At least one negative pressure generating groove may be formed which communicates with the annular groove and extends in a circumferential direction in which the opposing annular bodies rotate relative to each other. According to this, the liquid is returned from the negative pressure generating groove portion to the annular groove due to the relative rotation of the annular body, so that discharge of the liquid can be suppressed.

[0012] The supply grooves may be arranged in a plurality of equally spaced positions in the circumferential direction of the sliding surface. This allows the liquid to be guided evenly to the sliding surface at a plurality of locations in the circumferential direction, and the liquid can be effectively retained around the entire circumference of the annular recess.

[0013] The annular recess and the supply groove may be formed in an annular body fixed to a stationary side of the rotating machine. According to this, since the annular body fixed to the fixed side of the rotating machine is not affected by centrifugal force, the discharge of liquid that has entered the annular recess and supply groove can be suppressed, and lubrication can be maintained for a long period of time.

[0014] The supply groove may be formed deeper than the annular recess, and may open to an inner diameter side or an outer diameter side of at least one of a pair of sliding surfaces of the sliding component. With this, even when a relatively large amount of liquid is supplied, the liquid is less likely to return from the supply groove to the annular recess, making it easier to retain the liquid on the sliding surface.

[0015] The supply groove may be formed deeper than the annular recess and may communicate with the side of the annular recess opposite to the opening. According to this, the supply groove can easily take in liquid and a large amount of liquid can be held within the supply groove, so that lubrication can be maintained even with a small amount of liquid supplied.

[0016] The supply groove may be shallower than the annular recess and deeper than a dynamic pressure generating groove portion that communicates with the supply groove and extends in a circumferential direction in which the opposing annular bodies rotate relatively. This allows a relatively large amount of liquid to be held in the deeply formed annular recess, and the liquid can easily move radially within the shallowly formed supply groove, allowing it to be reliably guided to the dynamic pressure generating groove portion.

[0017] The annular recess and the supply groove may communicate with each other at the same depth. This allows the liquid to be smoothly guided from the annular recess to the supply groove.

[0018] The sliding component may constitute an outside-type mechanical seal that seals against leakage of a sealed fluid located on the inner diameter side to the outer periphery side. According to this, by forming the annular recess on the outer circumferential side, a large capacity for holding liquid can be ensured.

[0019] In the sliding part according to the present invention, the supply groove extends in the radial direction as long as the supply groove extends with at least a radial component, and the negative pressure generating groove extends in the circumferential direction of relative rotation as long as the negative pressure generating groove extends with at least a circumferential component. [Brief description of the drawings]

[0020] [Figure 1] 1 is a cross-sectional view showing a structure of a rotary machine in which a mechanical seal including a sliding component according to a first embodiment of the present invention is used. [Diagram 2] FIG. 2 is a view of a stationary seal ring of the mechanical seal as viewed from the sliding surface side. [Diagram 3] 3 is a cross-sectional view taken along the line AA in FIG. 2, showing a sliding contact state between the stationary seal ring and the rotary seal ring. [Figure 4] 3 is a cross-sectional view taken along the line BB in FIG. 2, showing a state in which a lubricant is supplied to the annular recess. [Diagram 5] FIG. 4 is a conceptual diagram showing the movement of fluid during relative rotation between a stationary seal ring and a rotating seal ring. [Figure 6] FIG. 11 is a cross-sectional view showing a sliding contact state between a stationary seal ring and a rotary seal ring in a second embodiment of the present invention. [Figure 7] FIG. 11 is a view of the stationary seal ring in Modification 1 as viewed from the sliding surface side. [Figure 8] 13 is a view of a stationary seal ring in Modification 2 as viewed from the sliding surface side. FIG. [Figure 9] FIG. 11 is a view of a stationary seal ring in Modification 3 as viewed from the sliding surface side. [Figure 10] FIG. 13 is a view of a stationary seal ring in Modification 4, as viewed from the sliding surface side. [Figure 11] FIG. 13 is a view of a stationary seal ring in Modification 5, as viewed from the sliding surface side. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of the sliding component according to the present invention will be described with reference to the accompanying drawings. EXAMPLES

[0022] A sliding component according to a first embodiment will be described with reference to FIGS.

[0023] The sliding parts in this embodiment are a rotating seal ring 3 and a stationary seal ring 6 that constitute a mechanical seal, which is a shaft sealing device that seals the rotating shaft of a rotating machine in, for example, an automobile, general industrial machine, or other sealing fields. The rotating seal ring 3 and the stationary seal ring 6 are each annular bodies of the present invention, and together they constitute the sliding part of the present invention. For ease of explanation, in the drawings, grooves and the like formed on the sliding surfaces are marked with dots.

[0024] As shown in Fig. 1, the mechanical seal is mainly composed of a rotating seal ring 3 and a stationary seal ring 6. The rotating seal ring 3 is annular, and is provided on a rotating shaft 1 via a sleeve 2 so as to be rotatable together with the rotating shaft 1. The stationary seal ring 6 is annular, and is provided on a seal cover 5 fixed to a housing 4 of a rotary machine so as to be non-rotating and movable in the axial direction. The stationary seal ring 6 is axially biased by a biasing means 7, so that a sliding surface S6 of the stationary seal ring 6 and a sliding surface 3S of the rotary seal ring 3 slide closely against each other.

[0025] That is, this mechanical seal is of the outside type, which prevents the sealed fluid on the inner peripheral side of the sliding surfaces S3, S6 between the rotating seal ring 3 and the stationary seal ring 6 from leaking out to the outer peripheral side, which is the leakage side. In this embodiment, the sealed fluid is a high-pressure gaseous fluid such as dry gas, and a low-pressure gaseous fluid such as air or dry gas exists on the outer peripheral side. Also, on the outer peripheral side, there is a supply source of lubricant Lu, which is a liquid such as lubricating oil, and the lubricant Lu is supplied little by little to the outer edges of the sliding surfaces S3, S6 between the rotating seal ring 3 and the stationary seal ring 6. The lubricant Lu is supplied, for example, by dripping.

[0026] The rotating seal ring 3 and the stationary seal ring 6 are typically formed by a combination of SiC (hard material) or SiC (hard material) and carbon (soft material), but any sliding material used for mechanical seals can be used. Examples of SiC include sintered bodies using boron, aluminum, carbon, and other sintering aids, as well as materials consisting of two or more phases with different components and compositions, such as SiC with dispersed graphite particles, reaction sintered SiC consisting of SiC and Si, SiC-TiC, and SiC-TiN, and examples of carbon include carbonaceous and graphitic mixtures, resin molded carbon, and sintered carbon. In addition to the above sliding materials, metal materials, resin materials, surface modification materials (coating materials), and composite materials can also be used.

[0027] 2 and 3, an annular recess 10, a supply groove 11, an annular groove 12, a Rayleigh step 13, and a spiral groove 14 are formed on the sliding surface S6 of the stationary seal ring 6. These can be formed by subjecting the sliding surface S6 to fine processing such as laser processing or sandblasting.

[0028] 2, an annular recess 10 is formed on the outer diameter edge of the sliding surface S6 of the stationary seal ring 6, extending in the circumferential direction concentrically with the stationary seal ring 6. The annular recess 10 is open in the outer diameter direction around the entire circumference, and is formed with the same width in the inner diameter direction and the same depth in the radial and circumferential directions.

[0029] Specifically, the annular recess 10 is defined by an inner diameter side wall 10a extending along the circumferential direction of the sliding surface S6 and in a direction perpendicular to the sliding surface S6, and a bottom surface 10e parallel to the sliding surface S6, and is open toward the sliding surface S3 of the opposing rotary seal ring 3 and toward the outer periphery. The annular recess 10 is formed so as to intersect with an annular chamfered portion 6a (see FIG. 3) formed on the outer diameter edge of the sliding surface S6 of the stationary seal ring 6.

[0030] A plurality of supply grooves 11 are formed in the sliding surface S6 of the stationary seal ring 6 and are arranged in a circumferentially separated manner. The start end 11a of the supply groove 11 is connected to the outer diameter side of the annular recess 10, and the end 11d is connected to an annular groove 12 (described later) on the inner diameter side. The supply grooves 11 are formed side by side with the same spacing in the circumferential direction, and are formed in a curved shape consisting of a component extending in the circumferential direction and extending in the radial direction while inclining in the rotational direction. The supply groove 11 is defined by walls 11b and 11c that are curved in a concave direction inclined in the rotational direction of the mating surface when viewed from above, and extend in a direction perpendicular to the sliding surface S6, and a bottom surface 11e (see FIG. 4) that is parallel to the sliding surface S6. The supply grooves 11 are connected to the annular recess 10 at the same depth.

[0031] On the inner peripheral side of the sliding surface S6 of the stationary seal ring 6, there is formed a single annular groove 12 extending circumferentially concentrically with the stationary seal ring 6 to which the end 11d of the supply groove 11 is connected. The annular groove 12 is connected to the stationary seal ring 6 at the same depth as the supply groove 11. The annular groove 12 is defined by an outer diameter side wall 12b, an inner diameter side wall 12a, and a bottom surface that extend along the circumferential direction of the sliding surface S6 and perpendicular to the sliding surface S6.

[0032] As shown in FIG. 2, a plurality of land portions 15 are formed, each of which is surrounded on all four sides by a wall 10a that defines the annular recess 10, walls 11b and 11c that define the supply groove 11, and a wall 12b that defines the annular groove 12, and is separated radially and circumferentially. The land portions 15 are spaced apart at predetermined intervals in the circumferential direction.

[0033] A Rayleigh step 13 is formed in the land portion 15 as a dynamic pressure generating groove portion extending in the circumferential direction concentrically with the stationary seal ring 6. The Rayleigh step 13 has an end 13d in the rotational direction of the rotary seal ring 3, and is defined by walls 13b and 13c extending parallel to the annular recess 10 and the annular groove 12, respectively, and closed by the end 13d, with a starting end 13a communicating with the supply groove 11. Note that the walls 13b and 13c do not have to be parallel to the annular recess 10 and the annular groove 12, and may have a tapered shape that gradually approaches the end 13d, for example.

[0034] The stationary seal ring 6 defines an annular land portion 16, which is isolated from the land portion 15 by the inner diameter side of the annular groove 12. The annular land portion 16 is formed with a plurality of spiral grooves 14 arranged circumferentially and separated from one another in the circumferential direction, serving as negative pressure generating groove portions. The land portion 15 and the annular land portion 16 have upper surfaces that are substantially flush with each other. The annular land portion 16 essentially serves as a sealing portion.

[0035] The spiral grooves 14 are formed side by side at the same spacing in the circumferential direction, and are formed in a curved shape consisting of a component extending in the circumferential direction and a component extending in the radial direction while inclining in the opposite direction to the rotation of the rotary seal ring 3. The spiral groove 14 is curved and inclined in the opposite direction to the rotation when viewed from above, and is defined by walls 14b, 14c extending in a direction perpendicular to the sliding surface S6, a starting end 14a, and a bottom surface, and an end end 14d communicates with the annular groove 12.

[0036] Next, the flow of the lubricant supplied when the rotary machine is in operation will be described with reference to Figures 4 and 5. The white arrow in Figure 5 indicates the relative rotation direction of the stationary seal ring 6, which is the mating sliding part.

[0037] When a small amount of lubricant Lu is dropped on the outer edge of the sliding surfaces S3, S6 of the rotary seal ring 3 and the stationary seal ring 6, the lubricant Lu is introduced into the annular recess 10 that opens on the outer periphery side of the sliding surface S6 of the stationary seal ring 6, as shown in Fig. 4. Since the annular recess 10 is continuously formed in the circumferential direction of the sliding surface S6, the lubricant Lu moves inside the annular recess 10 due to the relative rotation of the rotary seal ring 3 and the stationary seal ring 6, and adheres to the wall 10a and bottom surface 10e that define the annular recess 10 due to surface tension, particularly to the intersection of the wall 10a and bottom surface 10e, and is held in the annular recess 10 and is difficult to be discharged to the leakage side, i.e., the supply side of the lubricant Lu. In addition, the lubricant Lu has a convex contour due to its own viscosity and surface tension, and a large amount of lubricant Lu can be adhered and held at the intersection of the wall 10a and bottom surface 10e.

[0038] The lubricant Lu held in the annular recess 10 moves circumferentially within the annular recess 10 during relative rotation between the rotating seal ring 3 and the stationary seal ring 6, and a portion of the lubricant enters between the sliding surfaces S3, S6 in the radially inward direction. Most of the remaining lubricant is introduced into the supply groove 11, the start end 11a of which is connected to the annular recess 10.

[0039] 2, the supply groove 11 has a component extending in the rotational direction of the rotary seal ring 3 and a component extending in the radial direction, is formed with an inclination in the radial direction, and has a gently curved shape. Most of the lubricant Lu in the radial center part of the supply groove 11 is introduced into the Rayleigh step 13.

[0040] The lubricant Lu introduced into the Rayleigh step 13 generates dynamic pressure on the end 13d side within the Rayleigh step 13 due to the relative rotation of the opposing rotary seal ring 3, and this dynamic pressure causes a slight separation between the sliding surfaces S. This encourages the penetration of the lubricant Lu into the sliding surfaces S3, S6, and a liquid film is formed between the sliding surfaces S3, S6, improving the lubrication between the sliding surface S3 of the rotary seal ring 3 and the sliding surface S6 of the stationary seal ring 6.

[0041] Furthermore, the lubricant Lu introduced into the supply groove 11 in the radially inward direction is introduced into the annular groove 12 which communicates with the end 11d. The lubricant Lu introduced into the annular groove 12 moves inward and outward in the radial direction while following the relative rotation between the rotary seal ring 3 and the stationary seal ring 6, and is supplied between the sliding surfaces S3, S6, specifically between the opposing portion of the land portion 15 and the sliding surface S3 of the rotary seal ring 3 and between the opposing portion of the annular land portion 16 and the sliding surface S3 of the rotary seal ring 3.

[0042] As described above, the annular land portion 16 is formed with the spiral groove 14 extending in a direction in which negative pressure is generated during relative rotation between the rotary seal ring 3 and the stationary seal ring 6. Therefore, the lubricant Lu supplied to the sliding surface S6 of the land portion 16 is partially returned to the annular groove 12 by the negative pressure generated on the terminal end 14d side of the spiral groove 14 formed in the annular land portion 16 during relative rotation between the rotary seal ring 3 and the stationary seal ring 6. In addition, the lubricant Lu that has entered the spiral groove 14 is also pushed back into the annular groove 12 by the negative pressure generated on the terminal end 14d side of the spiral groove 14.

[0043] As described above, the annular recess 10 that opens in the radial direction over the entire circumference is formed on the outer diameter side of the sliding surface S3 of the rotary seal ring 3 and the sliding surface S6 of the stationary seal ring 6, and the supply groove 11 that extends in the radial direction of the sliding surfaces S3 and S6 is formed with its start end 11a connected to the annular recess 10. Since the annular recess 10 opens in the radial direction over the entire circumference, it is easy to take in the lubricant Lu that is supplied. In addition, a large amount of lubricant Lu can be held in the annular recess 10 and the supply groove 11 that communicates with the annular recess 10, and the lubricant Lu can be efficiently introduced between the sliding surfaces S3 and S6, so that high lubricity can be maintained for a long period of time.

[0044] In addition, the supply groove 11 extends at an angle in the relative rotation direction between the rotating seal ring 3 and the stationary seal ring 6, so that the lubricant Lu comes into contact with the bottom surface 11e of the supply groove 11 in two directions at the point where the bottom surface 11e and the wall 11c intersect, and the lubricant Lu is pressed against the wall 11c due to the relative rotation, making it easy to retain the lubricant Lu at the intersection of the bottom surface 11e and the wall 11c.

[0045] Furthermore, the lubricant Lu supplied to the annular recess 10 by the supply groove 11 is guided to the radial center of the sliding surface S3 of the rotary seal ring 3 and the sliding surface S6 of the stationary seal ring 6, thereby efficiently improving lubrication.

[0046] In addition, a large amount of lubricant Lu can be held in the internal space of the annular recess 10 that is open all around, and the supply groove 11 extends at an angle in the relative rotation direction between the rotary seal ring 3 and the stationary seal ring 6, so that the lubricant Lu introduced into the supply groove 11 follows the relative rotation direction due to the relative rotation between the rotary seal ring 3 and the stationary seal ring 6, and the lubricant Lu supplied to the annular recess 10 is easily guided to the radial center of the sliding surfaces S3, S6. In addition, the lubricant supplied between the sliding surfaces S3, S6 can be efficiently utilized to maintain high lubricity for a long period of time. In other words, it is particularly effective when there is no need to supply the lubricant Lu frequently and a large amount of lubricant Lu cannot be used depending on the usage environment.

[0047] Furthermore, since the supply grooves 11 are arranged at equal intervals in the circumferential direction of the sliding surface S6, the lubricant Lu can be effectively held around the entire circumference of the annular recess .

[0048] In addition, both the annular recess 10 and the supply groove 11 are formed in the same annular body, the stationary seal ring 6. With this, the annular recess 10 and the supply groove 11 are integrally continuous, so that when the lubricant Lu moves from the annular recess 10 to the supply groove 11, there is little turbulence generated near the starting end 11a, and the lubricant Lu moves smoothly from the annular recess 10 toward the terminal end 11d of the supply groove 11.

[0049] In addition, both the annular recess 10 and the supply groove 11 are formed in the stationary seal ring 6. With this, the stationary seal ring 6 fixed to the fixed side of the rotating machine is not affected by centrifugal force, so that discharge of the lubricant Lu that has entered the annular recess 10 and the supply groove 11 can be suppressed, and lubricity can be maintained for a long period of time.

[0050] In addition, since the annular recess 10 and the supply groove 11 are connected at the same depth, the lubricant Lu can be smoothly guided from the annular recess 10 to the supply groove 11, and the lubricant Lu can be efficiently guided toward the inner diameter side of the sliding surfaces S3, S6, thereby improving lubrication.

[0051] In addition, since the sliding surface S6 is formed with a Rayleigh step 13 that communicates with the supply groove 11 and extends in the circumferential direction in which the opposing rotary seal ring 3 rotates relative to the sliding surface S6, the lubricant Lu is guided from the supply groove 11 to the Rayleigh step 13 by the relative rotation, and dynamic pressure is generated at the end 13d of the Rayleigh step 13, which causes the sliding surfaces S3 and S6 to separate and form a liquid film, resulting in non-contact lubrication and improving lubricity. In addition, the guiding force of this dynamic pressure can be effectively utilized to hold the lubricant Lu in the annular recess 10, and the lubricant Lu can be efficiently guided toward the inner diameter side of the sliding surface S to improve lubricity.

[0052] In addition, the terminal end 11d of the supply groove 11 is connected to a single annular groove 12 extending along the circumferential direction, and the lubricant Lu is collected from the terminal end 11d of the supply groove 11 and circulated in the circumferential direction of the annular groove 12, thereby suppressing the discharge of the lubricant Lu.

[0053] Furthermore, the sliding component of this embodiment constitutes an outside-type mechanical seal that seals against leakage of the sealed fluid located on the inner diameter side to the outer periphery side, and the annular recess 10 is formed to open to the outer diameter side of the stationary seal ring 6, which is the supply side of the lubricant Lu. Therefore, it is possible to ensure a larger internal volume of the annular recess compared to the case where the annular recess is formed as an inside-type mechanical seal.

[0054] In the above embodiment, the annular recess 10 and the supply groove 11 are both formed in the stationary seal ring 6, but this is not limiting, and they may be formed in the sliding surface S3 of the rotating seal ring 3, or in both the sliding surface S3 of the rotating seal ring 3 and the sliding surface S6 of the stationary seal ring 6.

[0055] The annular recess 10 and the supply groove 11 may be formed separately in separate annular bodies. For example, the annular recess may be formed in the rotary seal ring 3, and the supply groove 11 may be formed in the stationary seal ring.

[0056] The shape of the supply groove 11 is not limited to a curved shape, and may be, for example, a straight line shape inclined in the circumferential direction and the radial direction, or a straight line shape that is bent.

[0057] In the above embodiment, the sliding parts are described as constituting a mechanical seal, but the present invention is not limited to this and can be used, for example, as a thrust bearing.

[0058] In the above embodiment, the sliding parts are described as outside-type mechanical seals that prevent the sealed fluid on the inner periphery side of the sliding faces S3, S6 as the sealed fluid side from flowing out to the outer periphery side as the leakage side, but the present invention is not limited to this, and may be an inside-type mechanical seal that prevents the sealed fluid on the outer periphery side of the sliding faces S3, S6 as the sealed fluid side from flowing out to the inner periphery side as the leakage side. The lubricant Lu may be supplied from either the inner periphery side or the outer periphery side of the sliding faces S3, S6, as long as the annular recess 10 is formed so as to open over the entire circumference on the supply side. EXAMPLES

[0059] Next, a sliding component according to a second embodiment will be described with reference to Fig. 6. Note that the same components as those shown in the above embodiment will be denoted by the same reference numerals and duplicated description will be omitted.

[0060] 6, the annular recess 20 has a tapered portion 20a formed so as to gradually approach the sliding surface S3 of the opposing rotary seal ring 3 as it approaches the opening. With this, the cross-sectional area of ​​the opening gradually narrows as it approaches the opening, making it easier to suppress the release of lubricant Lu from the inside of the annular recess 20 to the supply side.

[0061] Although the embodiments of the present invention have been described above with reference to the drawings, the specific configurations are not limited to these embodiments.

[0062] For example, the supply grooves 11 are not limited to a configuration in which a plurality of supply grooves 11 are equally spaced in the circumferential direction, but may be formed at different intervals, or a configuration in which only one supply groove is formed in the circumferential direction.

[0063] Further, the plurality of supply grooves 11 formed in the circumferential direction are not limited to a configuration in which all of them communicate with the annular groove 12 at the ends 11d, and the ends 11d of some of the supply grooves 11 may be closed.

[0064] Also, the annular recess 10 may be configured with a tapered surface formed so as to gradually separate from the opposing sliding surface S3 of the rotating seal ring 3 as it approaches the opening. In this way, the opening cross-sectional area gradually increases as it approaches the opening, making it easier to take in the lubricant Lu inside the annular recess 10.

[0065] As shown in Modification 1 of FIG. 7, the spiral groove 14 may be omitted.

[0066] 8, the annular groove 12 may be omitted in addition to the spiral groove 14. In this case, a continuous land portion 25 is formed between the circumferential space between adjacent supply grooves 11 and the inner diameter side of the closed end 11d of supply groove 11, i.e., the sealed fluid side, so that a substantial sliding area responsible for sealing performance can be secured large.

[0067] Also, the annular recess 10 and the supply groove 11 may be formed at different depths, and for example, as shown in Modification 3 of Fig. 9, the supply groove 11, which is deeper than the annular recess 10, may be formed to open to the outer diameter side of the stationary seal ring 6. With this, the supply groove 11 can easily take in the lubricant Lu, and a large amount of lubricant Lu can be held within the supply groove 11, so that lubrication can be maintained even with a small amount of lubricant Lu supplied.

[0068] 10, for example, supply groove 11 may be formed deeper than annular recess 10 and communicate with the inner diameter side of annular recess 10, i.e., the radially opposite side of the opening of annular recess 10. This allows the capacity of supply groove 11 to be increased, and the flow path cross-sectional area decreases sharply at the communication point between supply groove 11 and annular recess 10, making it difficult for lubricant Lu to return from supply groove 11 to annular recess 10 and making it easier to retain lubricant Lu between sliding surfaces S3 and S6.

[0069] 11, for example, supply groove 11 may be formed shallower than annular recess 10 and deeper than Rayleigh step 13. This allows the capacity of annular recess 10 to be increased and a large amount of lubricant Lu to be held. In addition, even if the amount of lubricant Lu to be supplied is small, lubricant Lu can easily move radially within supply groove 11 because supply groove 11 is shallow, and can be reliably guided to Rayleigh step 13.

[0070] Furthermore, the source of the lubricant may have any structure as long as it is capable of supplying liquid. For example, it may be oil used in the leaking mechanism that accumulates in droplets above the case and falls irregularly. [Explanation of symbols]

[0071] 1 Rotation axis 2 Sleeve 3 Rotating seal ring (ring, sliding part) 4. Housing 5 Seal cover 6 Static seal ring (ring, sliding part) 10 Annular recess 10a Wall 10e Bottom 11 Supply groove 11a Starting point 11b, 11c Wall 11d termination 12 Annular groove 12a,b wall 13 Rayleigh step (dynamic pressure generating groove) 13a Beginning 13b,c wall 13d termination 14 Spiral groove (negative pressure generating groove) 14a Beginning 14b, 14c Wall 14d termination 15 Land Department 16 Circular land section 20 Annular recess 20a Tapered section 25 Land Department Lu lubricant (liquid) S3, S6 sliding surfaces

Claims

1. A sliding component consisting of a pair of annular bodies arranged opposite to each other at a position where the rotating machine rotates relative to each other when the rotating machine is driven, A sliding component in which an annular recess that is open in the radial direction around the entire circumference is formed on an inner diameter side or an outer diameter side of at least one of a pair of sliding surfaces of the sliding component at a position facing the other of the pair of sliding surfaces, and a supply groove that communicates with the annular recess and extends in the radial direction of the sliding surfaces is formed in at least one of the pair of sliding surfaces.

2. 2. The sliding component according to claim 1, further comprising a dynamic pressure generating groove portion that communicates with the supply groove and extends in a circumferential direction in which the opposing annular bodies rotate relative to each other.

3. 3. The sliding component according to claim 1, wherein a terminal end of the supply groove is connected to a single annular groove extending along a circumferential direction.

4. 4. The sliding component according to claim 3, further comprising at least one negative pressure generating groove portion that communicates with the annular groove and extends in a circumferential direction in which the opposing annular bodies rotate relative to each other.

5. 5. The sliding element according to claim 1, wherein a plurality of the supply grooves are equally spaced in the circumferential direction of the sliding surface.

6. 6. The sliding component according to claim 1, wherein the annular recess and the supply groove are formed in an annular body fixed to a fixed side of the rotating machine.

7. 7. The sliding component according to claim 1, wherein the supply groove is formed deeper than the annular recess and opens to an inner diameter side or an outer diameter side of at least one of a pair of sliding surfaces of the sliding component.

8. 7. The sliding component according to claim 1, wherein the supply groove is formed deeper than the annular recess and communicates with the side of the annular recess opposite to the opening.

9. 7. The sliding component according to claim 1, wherein the supply groove is shallower than the annular recess and deeper than a dynamic pressure generating groove portion that communicates with the supply groove and extends in a circumferential direction in which the opposing annular body rotates relative to one another.

10. 7. The sliding component according to claim 1, wherein the annular recess and the supply groove communicate with each other at the same depth.

11. 11. The sliding component according to claim 1, which constitutes an outside-type mechanical seal for sealing against leakage of a sealed fluid located on an inner diameter side to an outer periphery side.

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