WO2025150435A1 - Sliding component - Google Patents

Abstract

The present invention provides a sliding component capable of enhancing sealability.　Provided are sliding components 10, 20 in which a pair of sliding surfaces 11, 21 rotate relative to each other and which divide a space between a sealed fluid space S1 and a leakage space S2, wherein: at least one of the sliding surfaces, e.g., the sliding surface 11 is provided with dynamic pressure generating grooves 13, and an endless annular groove 15 that is located closer to the leakage space S2 side than the dynamic pressure generating grooves 13 and that extends in the circumferential direction; the one sliding surface 11 or the other sliding surface 21 is provided with a pumping groove 14 provided closer to the sealed fluid space S1 side than the annular groove 15; and an end 14b of the pumping groove 14 that is positioned on the opposite side in the radial direction from the annular groove 15 and the dynamic pressure generating grooves 13 overlap each other in the circumferential direction.

Description

Sliding parts

The present invention relates to sliding parts that rotate relative to one another, such as sliding parts used in shaft sealing devices that seal the rotating shafts of rotating machines in automobiles, general industrial machines, or other sealing fields, or sliding parts used in bearings of machines in automobiles, general industrial machines, or other bearing fields.

Mechanical seals, for example, are shaft sealing devices that prevent leakage of sealed fluids and are equipped with a pair of annular sliding parts that rotate relative to one another and have sliding surfaces that slide against each other. In recent years, there has been a demand for reducing the energy lost through sliding in such mechanical seals for environmental reasons, etc.

For example, the mechanical seal shown in Patent Document 1 has multiple dimples arranged in the circumferential direction on the sliding surface of the stationary seal ring. The dimples are formed in a crank shape with a cavitation formation region and a positive pressure generation region. The cavitation formation region is located on the low pressure fluid side and is formed as a groove extending in the circumferential direction. The positive pressure generation region is located on the high pressure fluid side and is formed as a groove extending in the circumferential direction. In addition, the downstream end of the cavitation formation region in the direction of rotation and the upstream end of the positive pressure generation region in the direction of rotation are connected.

As the rotating seal ring rotates, the dimples guide the sealed fluid from the upstream side in the direction of rotation in the cavitation formation region to the downstream side in the direction of rotation in the positive pressure generation region, generating positive pressure at the downstream end. This positive pressure causes the mating sliding surfaces to float and introduces the sealed fluid between the sliding surfaces, reducing the energy lost due to sliding. In addition, the negative pressure generated at the upstream end in the direction of rotation in the cavitation formation region allows the dimples to recover the sealed fluid that has moved to the low pressure space.

Patent No. 6058018 (pages 8 and 9, Figure 4)

In the sliding parts of Patent Document 1, the positive pressure generating areas in the dimples are positioned close to the sealed fluid space, so that a portion of the sealed fluid can be recovered to the high pressure fluid side. However, the cavitation generating areas in the dimples are positioned so as to be scattered in the circumferential direction. This causes the negative pressure generated in the circumferential direction between the sliding surfaces to become uneven, which may impair sealing performance.

The present invention was made with an eye on these problems, and aims to provide a sliding part that can improve sealing performance.

In order to solve the above problems, the sliding component of the present invention comprises:
A sliding component having a pair of sliding surfaces that rotate relative to each other and partition a sealed fluid space and a leakage space,
at least one of the sliding surfaces includes a dynamic pressure generating groove and an annular groove that is located closer to the leakage space than the dynamic pressure generating groove and extends in a circumferential direction, and the one sliding surface or the other sliding surface includes a pumping groove that is provided closer to the sealed fluid space than the annular groove,
An end portion of the pumping groove located radially opposite the annular groove overlaps with the dynamic pressure generating groove in the circumferential direction.
According to this, the pumping groove allows the fluid to flow from the annular groove to the sealed fluid space, and the annular groove is likely to be under relatively negative pressure. As a result, the annular groove can recover the fluid that has flowed out between the sliding surfaces over the entire circumference, improving the sealing performance. In addition, since the pumping groove and the dynamic pressure generating groove overlap in the circumferential direction, the dynamic pressure generating groove can be disposed close to the annular groove, so that the fluid can be supplied from the dynamic pressure generating groove to the annular groove, and excessive poor lubrication of the annular groove can be avoided.

The dynamic pressure generating groove may be in communication with the sealed fluid space.
This improves the effect of generating dynamic pressure by the dynamic pressure generating grooves.

The pumping groove may be in communication with the annular groove.
This allows the fluid to flow smoothly from the annular groove to the pumping groove, making it easier for a relative negative pressure to be generated in the annular groove.

The pumping groove may be a plurality of grooves arranged in the circumferential direction.
According to this, since the fluid can be discharged between the sliding surfaces from a plurality of points in the circumferential direction of the annular groove, a relative negative pressure can be generated in a well-balanced manner over the circumferential direction of the annular groove.

The annular groove may be a circular ring.
This makes it possible to generate a relative negative pressure in a well-balanced manner around the circumference of the annular groove.

The pumping groove may extend in a radial direction toward the sealed fluid space.
This allows the fluid to be pushed towards the sealed fluid side, thereby reducing leakage.

1 is a vertical cross-sectional view showing an example of a mechanical seal according to a first embodiment of the present invention. 4 is a view showing a sliding surface of a stationary seal ring in the first embodiment as viewed from the axial direction. FIG. FIG. 3 is a partially enlarged view of FIG. 2 . FIG. 11 is a partially enlarged view of a sliding surface of a stationary seal ring according to a second embodiment of the present invention, as viewed from the axial direction. FIG. 11 is a partially enlarged view of a sliding surface of a stationary seal ring according to a third embodiment of the present invention, as viewed from the axial direction. FIG. 11 is a partially enlarged view of a sliding surface of a stationary seal ring according to a fourth embodiment of the present invention, as viewed from the axial direction. FIG. 11 is a partially enlarged view of a sliding surface of a stationary seal ring according to a fifth embodiment of the present invention, as viewed from the axial direction. FIG. 13 is a partially enlarged view of a sliding surface of a stationary seal ring according to a sixth embodiment of the present invention, as viewed from the axial direction.

The following describes the implementation of the sliding parts according to the present invention.

The sliding part of the first embodiment will be described with reference to Figures 1 to 3. In this embodiment, the sliding part will be described as being applied to a mechanical seal.

Furthermore, the mechanical seal has an inner space S1 in which a sealed fluid F exists as a first fluid, and an outer space S2 in which atmosphere A exists as a second fluid. The inner diameter side of the sliding parts that make up the mechanical seal will be described as the sealed fluid space side (high pressure side), and the outer diameter side as the leakage space side (low pressure side). For ease of explanation, dots may be added to grooves formed on the sliding surfaces in the drawings.

The mechanical seal shown in Figure 1 is an outside type that seals the sealed fluid F that is trying to leak from the inner diameter side to the outer diameter side of the sliding surface, and the outer space S2 is connected to the atmosphere A. In this embodiment, the sealed fluid F is a high-pressure liquid, and the atmosphere A is a gas with a lower pressure than the sealed fluid F.

The mechanical seal is mainly composed of a stationary seal ring 10 as an annular sliding part, and a rotating seal ring 20 as another annular sliding part. The rotating seal ring 20 is mounted on a rotating shaft 1 via a sleeve 2 in a state in which it can rotate together with the rotating shaft 1. The stationary seal ring 10 is mounted on a seal cover 5 fixed to a housing 4 of the device to which it is attached in a state in which it is non-rotating and axially movable. The stationary seal ring 10 is biased in the axial direction by an elastic member 7, so that the sliding surface 11 of the stationary seal ring 10 and the sliding surface 21 of the rotating seal ring 20 slide closely against each other. The sliding surface 21 of the rotating seal ring 20 is flat, and this flat surface does not have any recesses such as grooves.

The stationary seal ring 10 and the rotating seal ring 20 are typically made of SiC (hard material) or SiC (hard material) and carbon (soft material), but are not limited to this and any sliding material used as a sliding material for mechanical seals can be used. Examples of SiC include sintered bodies using boron, aluminum, carbon, etc. as 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, SiC-TiN, etc., and examples of carbon include carbonaceous and graphitic mixtures, resin molded carbon, sintered carbon, etc. In addition to the above sliding materials, metal materials, resin materials, surface modified materials (coating materials), composite materials, etc. can also be used.

As shown in Figures 2 and 3, the rotating seal ring 20, which is the mating seal ring, slides counterclockwise relative to the stationary seal ring 10 as indicated by the solid arrow.

The sliding surface 11 of the stationary seal ring 10 is provided with a dynamic pressure groove 13 as a dynamic pressure generating groove, a pumping groove 14, and an annular groove 15.

The dynamic pressure grooves 13 are evenly arranged circumferentially on the inner diameter side of the sliding surface 11 (for example, 32 in this embodiment).

The dynamic pressure groove 13 extends linearly from the inner diameter end 13a on the inner space S1 side to the outer diameter end 13b on the outer space S2 side, inclined toward the downstream side in the rotation direction of the rotating seal ring 20, i.e., toward the downstream side in the relative rotation. The inner diameter end 13a of the dynamic pressure groove 13 is connected to the inner space S1, and the outer diameter end 13b, which serves as a dynamic pressure generating portion, is closed. Note that this dynamic pressure groove 13 is not limited to being linear when viewed in the axial direction, but may be arc-shaped or spiral-shaped, etc. Also, it may be a dimple surrounded by a land, etc.

An annular groove 15 is provided on the outer diameter side of the dynamic pressure groove 13. This annular groove 15 is provided concentrically with the stationary seal ring 10. The sliding surface 11 is provided with a flat land 12 other than the dynamic pressure groove 13, the pumping groove 14, and the annular groove 15.

In addition, the annular groove 15 in this embodiment is formed to the same depth as the dynamic pressure groove 13 and the pumping groove 14. The annular groove 15 may have a different depth from the dynamic pressure groove 13 and the pumping groove 14. If the annular groove 15 is shallow, it is easier to generate a relative negative pressure, which makes it easier to recover the sealed fluid. If the annular groove 15 is deep, the sealed fluid can be reliably supplied to the pumping groove 14 compared to a shallow annular groove, resulting in superior pumping efficiency. In this way, the depth of the annular groove 15 can be selected appropriately depending on the conditions of use.

Pumping grooves 14 are evenly arranged around the circumference on the inner diameter side of the annular groove 15 (for example, four in this embodiment).

The pumping groove 14 extends linearly from the outer diameter end 14a on the outer space S2 side to the inner diameter end 14b on the inner space S1 side, tilting in the circumferential direction toward the downstream side in the rotational direction of the rotating seal ring 20, i.e., toward the downstream side of the relative rotation. The outer diameter end 14a of the pumping groove 14 is connected to the annular groove 15, and the inner diameter end 14b, which is the end located radially opposite the annular groove 15, is closed. Note that this pumping groove 14 is not limited to being linear when viewed in the axial direction, but may be arc-shaped, or approximately J-shaped or L-shaped when viewed in the axial direction. Note that the radial direction in this invention may include at least a radial component, and the circumferential direction in this invention may include at least a circumferential component.

The inner diameter end 14b of the pumping groove 14 is disposed on the inner diameter side of the outer diameter end 13b of the dynamic pressure groove 13. In other words, the pumping groove 14 and the dynamic pressure groove 13 are formed in a position where they overlap when viewed from the circumferential direction. In this way, an arrangement in a position where they overlap when viewed from the circumferential direction is expressed in the present invention as overlapping in the circumferential direction. Similarly, an arrangement in a position where they overlap when viewed from the radial direction is expressed in the present invention as overlapping in the radial direction.

Next, we will provide a brief explanation of the function of the dynamic pressure grooves 13 and pumping grooves 14 during relative rotation between the stationary seal ring 10 and the rotating seal ring 20.

As shown in FIG. 3, when the rotating seal ring 20 rotates relative to the stationary seal ring 10, the fluid in the dynamic pressure groove 13, pumping groove 14, and annular groove 15 moves in response to the relative rotation of the rotating seal ring 20.

Specifically, in the dynamic pressure groove 13, as shown by the black arrow in FIG. 3, the sealed fluid F moves from the inner diameter end 13a to the outer diameter end 13b. This generates positive pressure at the outer diameter end 13b and its vicinity. In addition, the sealed fluid F is constantly supplied to the dynamic pressure groove 13 from the internal space S1 through the inner diameter end 13a.

A portion of the sealed fluid F discharged between the sliding surfaces 11, 21 from the outer diameter end 13b and its vicinity flows into the pumping groove 14 or the annular groove 15.

On the other hand, in the pumping groove 14, as shown by the white arrow in Figure 3, the fluid moves from the outer diameter end 14a to the inner diameter end 14b, and is discharged from the inner diameter end 14b between the sliding surfaces 11 and 21. This generates a slight positive pressure at and near the inner diameter end 14b of the pumping groove 14.

In addition, a relative negative pressure is generated near the outer diameter end 14a of the pumping groove 14 and in the annular groove 15. This makes it easier for the sealed fluid F discharged between the sliding surfaces 11 and 21 to be collected in the pumping groove 14 and the annular groove 15.

Also, most of the fluid discharged from the inner diameter end 14b of the pumping groove 14 between the sliding surfaces 11, 21 flows into the adjacent dynamic pressure groove 13 on the downstream circumferential side.

As explained above, the pumping groove 14 is provided on the inner diameter side of the annular groove 15, i.e., on the inner space S1 side, and when the sliding surfaces 11, 21 rotate relative to each other, the pumping groove 14 causes fluid to flow from the annular groove 15 to the inner space S1 side, creating a relatively negative pressure in the annular groove 15. As a result, the fluid that has flowed out between the sliding surfaces 11, 21 can be recovered over the entire circumference by the annular groove 15, so that leakage of the sealed fluid F into the outer space S2 side is suppressed, and the sealing performance can be improved.

In addition, since the pumping groove 14 is connected to the annular groove 15, the fluid flows smoothly from the annular groove 15 to the pumping groove 14, so that a relative negative pressure is easily generated in the annular groove 15.

Furthermore, the pumping grooves 14 are arranged at equal intervals in the circumferential direction. This allows fluid to be discharged between the sliding surfaces 11, 21 from multiple points in the circumferential direction of the annular groove 15, so that negative pressure can be generated in a well-balanced manner.

In addition, positive pressure can be generated at the inner diameter ends 14b of the pumping grooves 14 that are evenly spaced in the circumferential direction, improving the floating balance between the stationary seal ring 10 and the rotating seal ring 20.

In addition, because the annular groove 15 is a ring, pressure bias is unlikely to occur in the circumferential direction of the annular groove 15, and negative pressure can be generated in a balanced manner in the circumferential direction.

In addition, dynamic pressure grooves 13 are provided on the inner space S1 side of the annular groove 15, and positive pressure can be generated at multiple points in the circumferential direction by the pumping grooves 14 and the dynamic pressure grooves 13. This improves the floating balance between the stationary seal ring 10 and the rotating seal ring 20, thereby improving lubrication.

In addition, since the inner diameter end 14b of the pumping groove 14 is located on the inner diameter side of the outer diameter end 13b of the dynamic pressure groove 13, the positive pressure generated at the inner diameter end 14b of the pumping groove 14 and the positive pressure generated at the outer diameter end 13b of the dynamic pressure groove 13 are unlikely to interfere with each other. Furthermore, the pumping groove 14 and the dynamic pressure groove 13 can generate positive pressure in a balanced manner in the radial direction of the sliding surfaces 11, 21. Furthermore, since the pumping groove 14 extends radially toward the sealed fluid space side, i.e., the inner space S1 side, the fluid is pushed out toward the sealed fluid side, thereby reducing leakage.

In addition, since the inner diameter end 14b of the pumping groove 14 is positioned circumferentially to the side of the dynamic pressure groove 13, more specifically, on the upstream side of the relative rotation, the fluid that flows out from the inner diameter end 14b of the pumping groove 14 between the sliding surfaces 11, 21 can be easily collected by the dynamic pressure groove 13.

In addition, since the outer diameter end 13b of the dynamic pressure groove 13 is positioned circumferentially to the side of the pumping groove 14, more specifically, on the upstream side of the relative rotation, that is, the pumping groove 14 and the dynamic pressure groove 13 overlap in the circumferential direction, the fluid that flows out from the outer diameter end 13b of the dynamic pressure groove 13 between the sliding surfaces 11, 21 can be easily collected by the pumping groove 14.

Furthermore, because the pumping groove 14 and the dynamic pressure groove 13 overlap in the circumferential direction, the outer diameter end 13b of the dynamic pressure groove 13 can be positioned close to the annular groove 15, so that fluid can be supplied from the dynamic pressure groove 13 to the annular groove 15, and excessive poor lubrication of the annular groove 15 can be prevented.

In addition, since the dynamic pressure groove 13 is connected to the inner space S1, the sealed fluid F in the dynamic pressure groove 13 does not run out, and the dynamic pressure generation effect is high.

In addition, since the dynamic pressure groove 13 is not connected to the annular groove 15, it is possible to generate a stable positive pressure without being affected by fluctuations in pressure within the annular groove 15.

Furthermore, the fluid present between the sliding surfaces 11, 21 may contain contaminants, and if contaminants are present between the lands, there is a risk of abnormal noise, damage, etc. occurring. In this embodiment, the fluid discharged from the dynamic pressure groove 13 can discharge the contaminants into the annular groove 15, and the fluid discharged from the pumping groove 14 can discharge the contaminants into the dynamic pressure groove 13 located downstream of the relative rotation. This makes it possible to prevent contaminants from remaining between the lands.

In addition, multiple dynamic pressure grooves 13 are provided between the two pumping grooves 14, so contaminants between the lands can be discharged over a wide area into the annular groove 15.

Furthermore, by ensuring a large circumferential width between the pumping groove 14 and the dynamic pressure groove 13 arranged downstream of the relative rotation, the dynamic pressure generated in the pumping groove 14 is less likely to interfere with the dynamic pressure groove 13 arranged downstream of the relative rotation, thereby improving sealing performance.Furthermore, by ensuring a large circumferential width between the pumping groove 14 and the dynamic pressure groove 13 arranged upstream of the relative rotation, the dynamic pressure generated in the dynamic pressure groove 13 is less likely to interfere with the pumping groove 14, thereby improving the floating effect between the sliding surfaces.

In this embodiment, the annular groove 15 has a rectangular cross section, but the cross section may be U-shaped, semicircular, triangular, or may be modified as appropriate. The same applies to the dynamic pressure groove 13 and the pumping groove 14.

In addition, in this embodiment, the annular groove 15 is illustrated as having a circular ring shape, but as long as it is endless, it may have a wave shape when viewed in the axial direction, or a star-shaped polygon shape, etc.

In addition, in this embodiment, a configuration in which multiple pumping grooves 14 are provided in the circumferential direction is exemplified, but it is sufficient to provide at least one.

Next, the sliding parts of Example 2 will be described with reference to FIG. 4. Note that descriptions of the same configuration as in Example 1 will be omitted.

As shown in FIG. 4, in the stationary seal ring 410 of this embodiment 2, the outer diameter end 414a of the pumping groove 414 is disposed close to the annular groove 415 and is not connected to it. For example, the distance between the outer diameter end 414a and the annular groove 415 may be less than or equal to the groove width of the annular groove 415.

When the stationary seal ring 410 and the rotating seal ring 20 rotate relative to each other, the fluid in the annular groove 415 is sucked in by the negative pressure generated near the outer diameter end 414a of the pumping groove 414, creating a relative negative pressure in the annular groove 415. In addition, because negative pressure is generated near the outer diameter end 414a, it becomes easier to directly suck in the sealed fluid between the sliding surfaces from near the outer diameter end 414a.

Next, the sliding parts of Example 3 will be described with reference to FIG. 5. Note that descriptions of the same configuration as Example 1 will be omitted.

As shown in FIG. 5, the pumping groove 514 in the stationary seal ring 510 of this embodiment 3 is composed of a first groove portion 514A and a second groove portion 514B.

The first groove portion 514A extends from the annular groove 515 toward the inner diameter while inclining toward the downstream side in the relative rotation direction. The second groove portion 514B extends from the inner diameter end of the first groove portion 514A toward the inner diameter while inclining toward the upstream side in the relative rotation direction. In other words, an acutely bent corner portion 514C is formed between the first groove portion 514A and the second groove portion 514B.

In addition, the dynamic pressure grooves 513 are arranged between adjacent pumping grooves 514 in the circumferential direction.

When the stationary seal ring 510 and the rotating seal ring 20 rotate relative to each other, fluid flows from the annular groove 515 to the first groove portion 514A. The fluid in the first groove portion 514A flows from its outer diameter end 514a toward the corner portion 514C. The fluid in the second groove portion 514B flows from its inner diameter end 514b toward the corner portion 514C. As a result, positive pressure is generated at the corner portion 514C and its vicinity.

In addition, the fluid that flows out between the sliding surfaces from the outer diameter end 513b of the dynamic pressure groove 513 is collected at the inner diameter end 514b of the second groove portion 514B located downstream in the relative rotation direction of the outer diameter end 513b, so that the high-pressure sealed fluid F that flows out between the sliding surfaces from the dynamic pressure groove 513 can be used to efficiently generate positive pressure at the corner portion 514C and its vicinity.

Next, the sliding parts of Example 4 will be described with reference to FIG. 6. Note that descriptions of the same configuration as in Example 1 will be omitted.

As shown in FIG. 6, the stationary seal ring 810 of this embodiment 4 has dynamic pressure grooves 813A, 813B, and 813C of different lengths between two pumping grooves 814.

The dynamic pressure groove 813A located furthest upstream in the relative rotation direction is shorter than the adjacent dynamic pressure groove 813B located downstream in the relative rotation direction, and the dynamic pressure groove 813B is shorter than the adjacent dynamic pressure groove 813C located downstream in the relative rotation direction.

Some of the contamination present on the land near the outer diameter end 813Ab of dynamic pressure groove 813A is pushed out near the outer diameter end 813Bb of dynamic pressure groove 813B. Some of the contamination present on the land near the outer diameter end 813Bb of dynamic pressure groove 813B is pushed out near the outer diameter end 813Cb of dynamic pressure groove 813C. Contamination present on the land near the outer diameter end 813Cb of dynamic pressure groove 813C is pushed out into the annular groove 815. In other words, contamination can be discharged into the annular groove 815 over a wide radial range.

Also, the outer diameter ends 813Ab, 813Bb, and 813Cb are farther from the annular groove 815 in the order of their proximity to the upstream pumping groove 814. Fluid flows from the upstream pumping groove 814 toward the downstream side. As a result, the fluid pushed out from the outer diameter ends 813Ab, 813Bb, and 813Cb and the upstream pumping groove 814 toward the annular groove 815 is uniform in the circumferential direction.

Note that, although the example shows that the dynamic pressure grooves 813A, 813B, and 813C become longer toward the downstream side in the relative rotation direction, the length of each dynamic pressure groove may be freely changed.

Next, the sliding parts of Example 5 will be described with reference to FIG. 7. Note that descriptions of the same configuration as in Example 1 will be omitted.

As shown in FIG. 7, the stationary seal ring 910 of this embodiment 5 has pumping grooves 914 and dynamic pressure grooves 913 arranged alternately in the circumferential direction. This allows the positive pressure generated in the pumping grooves 914 and the positive pressure generated in the dynamic pressure grooves 913 to act in a well-balanced manner in the circumferential direction.

Next, the sliding parts of Example 6 will be described with reference to FIG. 8. Note that descriptions of the same configuration as in Example 1 will be omitted.

The mechanical seal to which the stationary seal ring 710 of this embodiment 6 is applied seals the sealed fluid F present on the outer space S12 side of the sliding surfaces 711, 21, and is an inside type in which the inner space S11 is connected to the atmosphere A.

The sliding surface 711 is formed with a plurality of pumping grooves 714, a plurality of dynamic pressure grooves 713, and an annular groove 715.

The pumping groove 714 and the dynamic pressure groove 713 have a shape that is roughly the radial inversion of the pumping groove 14 and the dynamic pressure groove 13 in the first embodiment. In other words, the pumping groove 714 is provided on the outer diameter side of the annular groove 715, and the dynamic pressure groove 713 is connected to the outer space S12.

As a result, as shown by the solid arrows, the rotation of the rotating seal ring 20 causes fluid to flow from the annular groove 715 toward the pumping groove 714, generating a relative negative pressure in the annular groove 715. In addition, positive pressure is generated at the outer diameter end 714a of the pumping groove 714 and in its vicinity. In addition, positive pressure is generated at the inner diameter end 713a of the dynamic pressure groove 713 and in its vicinity.

In this way, the sliding component of the present invention may be applied to an environment in which the sealed fluid space is on the outer diameter side of the sliding surface and the leakage space is on the inner diameter side of the sliding surface.

Although 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 the present invention also includes modifications and additions that do not deviate from the gist of the present invention.

For example, in the above-mentioned Examples 1 to 6, a form in which a dynamic pressure generating groove is provided in the sliding part is exemplified, but the sliding part only needs to be provided with an annular groove and a pumping groove, and the dynamic pressure generating groove may be omitted.

In addition, in the above embodiments 1 to 6, a mechanical seal for an automobile is used as an example of a sliding part, but other mechanical seals for general industrial machinery, etc. may also be used. Furthermore, the sliding part is not limited to a mechanical seal, and may be a sliding bearing or other sliding part other than a mechanical seal.

In addition, in the above embodiments 1 to 6, the sealed fluid was described as a high-pressure liquid, but it is not limited to this and may be a gas or low-pressure liquid, or a mist-like mixture of liquid and gas.

In addition, in the above embodiments 1 to 6, the fluid on the leakage space side was described as air, which is a low-pressure gas, but it is not limited to this and may be liquid or high-pressure gas, or a mist-like mixture of liquid and gas.

In addition, in the above embodiments 1 to 6, the sealed fluid space side has been described as the high pressure side and the leakage space side as the low pressure side, but the sealed fluid space side may be the low pressure side and the leakage space side may be the high pressure side, or the sealed fluid space side and the leakage space side may be at approximately the same pressure.

In addition, in the above embodiments 1 to 6, examples have been described in which the dynamic pressure generating grooves and pumping grooves are provided in the stationary seal ring, but the dynamic pressure generating grooves and pumping grooves may also be provided in the rotating seal ring.

In addition, in the above-mentioned Examples 1 to 6, the dynamic pressure generating groove and the pumping groove are provided in the same sliding part, but the dynamic pressure generating groove and the pumping groove may be provided in separate sliding parts. Also, the dynamic pressure generating groove and the pumping groove may be provided in both sliding parts.

10 Stationary seal ring (sliding part)
11 sliding surface 13 dynamic pressure groove (dynamic pressure generating groove)
13b Outer diameter end (dynamic pressure generating part)
14 Pumping groove (pumping groove)
14b Inner diameter end (end)
15 Annular groove 20 Rotary seal ring (sliding part)
21 Sliding surface A Air (pumping groove)
F Sealed fluid S1 Inner space (pumping groove)
S2 External space (leakage space)

Claims (6)

A sliding component having a pair of sliding surfaces that rotate relative to each other and partition a sealed fluid space and a leakage space,
at least one of the sliding surfaces includes a dynamic pressure generating groove and an annular groove that is located closer to the leakage space than the dynamic pressure generating groove and extends in a circumferential direction, and the one sliding surface or the other sliding surface includes a pumping groove that is provided closer to the sealed fluid space than the annular groove,
a sliding component in which an end portion of the pumping groove located radially opposite the annular groove and the dynamic pressure generating groove overlap in the circumferential direction; The sliding component according to claim 1, wherein the dynamic pressure generating groove is in communication with the sealed fluid space. The sliding part according to claim 1, wherein the pumping groove is connected to the annular groove. The sliding part according to claim 1, wherein the pumping grooves are arranged in a circumferential direction. The sliding part according to claim 1, wherein the annular groove is a ring. The sliding component according to claim 1, wherein the pumping groove extends radially toward the sealed fluid space.