Sliding parts

Abstract

Provided is a sliding component that can keep a first fluid and a second fluid from mixing between sliding surfaces.　A sliding component according to the present invention demarcates a first fluid space S1 and a second fluid space S2 and has a pair of sliding rings 10, 20 that have sliding surfaces that rotate relative to each other. At least one sliding surface 11 has a first reservoir groove 15 that is provided on the first fluid space S1 side, a second reservoir groove 16 that is provided further to the second fluid space S2 side than the first reservoir groove 15 so as to be separated from the first reservoir groove 15 in the radial direction, a first dynamic pressure mechanism 13 that is provided further to the first fluid space S1 side than the first reservoir groove 15 and introduces fluid from the first reservoir groove 15 to generate dynamic pressure, and a second dynamic pressure mechanism 14 that is provided further to the second fluid space S2 side than the second reservoir groove 16 and introduces fluid from the second reservoir groove 16 to generate dynamic pressure.

Description

[Technical Field]

[0001] The present invention relates to a sliding part used in a shaft seal or a bearing. [Background technology]

[0002] In rotary machines, a mechanical seal consisting of a pair of annular sliding rings that rotate relative to each other and whose sliding surfaces slide against each other is known as a sliding component for preventing leakage of a sealed fluid around a rotating shaft. In recent years, there has been a demand for reducing the energy lost due to sliding, for example, in order to protect the environment, and some mechanical seals have dynamic pressure generating grooves on the sliding surfaces of the sliding rings.

[0003] For example, Patent Document 1 discloses a mechanical seal having a sliding surface of one sliding ring, which has a first negative pressure generating groove and a dynamic pressure generating groove on its inner diameter side and a second negative pressure generating groove on its outer diameter side. The first negative pressure generating groove is partitioned by an annular land so as to be in a non-communicating state with a second fluid space on the outer diameter side, and the second negative pressure generating groove is partitioned by an annular land so as to be in a non-communicating state with a first fluid space on the inner diameter side. The dynamic pressure generating groove is disposed on the inner diameter side of the first negative pressure generating groove. Furthermore, one circumferential groove is formed between the first negative pressure generating groove and the second negative pressure generating groove, and another circumferential groove is formed between the first negative pressure generating groove and the dynamic pressure generating groove.

[0004] During relative forward rotation of the pair of sliding rings, dynamic pressure is generated at the closed ends of the dynamic pressure generating grooves by the first fluid on the inner diameter side, causing the sliding surfaces to separate slightly, improving lubrication between the sliding surfaces. Furthermore, the first fluid that flows out from the closed ends of the dynamic pressure generating grooves between the sliding surfaces is sucked into the first negative pressure generating grooves and discharged to other circumferential grooves. Furthermore, as the sliding surfaces separate, the second fluid that flows between the sliding surfaces from the second fluid space on the outer diameter side is sucked into the second negative pressure generating grooves and returned to the second fluid space. This ensures lubrication between the sliding surfaces while preventing the first fluid from flowing into the second fluid space or the second fluid from flowing into the first fluid space. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2018 / 092742 (page 11, Figure 3) Summary of the Invention [Problem to be solved by the invention]

[0006] The mechanical seal of Patent Document 1 can prevent the first fluid from flowing into the second fluid space or the second fluid from flowing into the first fluid space, but there is a risk that the first fluid that has radially passed over the first negative pressure generating groove or the second fluid that has radially passed over the second negative pressure generating groove will be mixed within a single circumferential groove provided between the first and second negative pressure generating grooves between the sliding surfaces.

[0007] The present invention has been made in view of these problems, and has an object to provide a sliding component that can prevent the first fluid and the second fluid from mixing between the sliding surfaces. [Means for solving the problem]

[0008] In order to solve the above problems, the sliding component of the present invention comprises: A sliding component in which sliding surfaces of a pair of sliding rings rotate relative to each other to partition a first fluid space and a second fluid space, At least one of the sliding surfaces is a first reservoir groove provided on the first fluid space side and extending in a circumferential direction; a second retention groove extending in a circumferential direction and provided radially separated from the first retention groove on the second fluid space side of the first retention groove; a first dynamic pressure mechanism that is provided closer to the first fluid space than the first storage groove and has a depth shallower than the first storage groove; The second dynamic pressure mechanism is provided closer to the second fluid space than the second storage groove and has a shallower depth than the second storage groove. With this, the first fluid that passes over the first dynamic pressure mechanism and flows toward the second fluid space is collected in the first storage groove, and the second fluid that passes over the second dynamic pressure mechanism and flows toward the first fluid space is collected in the second storage groove, so mixing of the first fluid and the second fluid between the sliding surfaces is suppressed, and the first fluid and the second fluid are temporarily stored in the first storage groove and the second storage groove, respectively, in a state where mixing is prevented, thereby improving the lubrication effect between the sliding surfaces. Also, interference between the dynamic pressures due to the first dynamic pressure mechanism and the second dynamic pressure mechanism is suppressed by the first storage groove and the second storage groove, which are provided at a distance from each other.

[0009] At least one of the combinations of the first dynamic pressure mechanism and the first reservoir groove, and the second dynamic pressure mechanism and the second reservoir groove may be in communication with each other. This allows fluid to circulate between the dynamic pressure mechanism and the reservoir groove of the communicating pair.

[0010] At least one of the first retention groove and the second retention groove may be annular. This allows the first fluid and the second fluid to be reliably collected over the entire circumference by the first storage groove and the second storage groove.

[0011] At least one of a closed end of the first dynamic pressure mechanism inclined toward the first fluid space side and a closed end of the second dynamic pressure mechanism inclined toward the second fluid space side may be formed. With this, the first fluid is discharged from the closed end of the first dynamic pressure mechanism into the first fluid space, and the second fluid is discharged from the closed end of the second dynamic pressure mechanism into the second fluid space, so that the first fluid can be efficiently returned to the first fluid space, and the second fluid can be efficiently returned to the second fluid space. In this way, mixing of the first and second fluids can be more effectively prevented, and interference between the dynamic pressures generated by the first dynamic pressure mechanism and the second dynamic pressure mechanism is less likely to occur.

[0012] At least one of the first dynamic pressure mechanism and the second dynamic pressure mechanism may have a one-way groove extending to one side in the circumferential direction and an other-way groove extending to the other side in the circumferential direction. This allows the one-way groove to function when the sliding parts rotate relative to each other in the forward direction, and the other-way groove to function when the sliding parts rotate relative to each other in the reverse direction, thereby making it possible to accommodate both rotations of the sliding parts.

[0013] The one-directional groove and the other-directional groove may be in communication with each other. This allows fluid to flow between the one-way groove and the other-way groove.

[0014] A third dynamic pressure mechanism may be provided on at least one side of the first dynamic pressure mechanism on the first fluid space side and the second dynamic pressure mechanism on the second fluid space side. This makes it easier for the third dynamic pressure mechanism to separate the sliding surfaces, improving lubrication performance.

[0015] An independent pressure release mechanism may be provided between the first reservoir groove and the second reservoir groove. With this, the independent pressure release mechanism between the first and second storage grooves prevents interference between the dynamic pressure generated by the first dynamic pressure mechanism and the dynamic pressure generated by the second dynamic pressure mechanism. Also, the independent pressure release mechanism between the first and second storage grooves can recover the first fluid or second fluid that has radially exceeded the first or second storage groove, further preventing the first and second fluids from mixing.

[0016] At least one of the first and second reservoir grooves may be annular. With this, no corners are formed in the first and second storage grooves, so that no dynamic pressure is generated during relative rotation, making it easier to store the first and second fluids in the first and second storage grooves.

[0017] a plurality of the first dynamic pressure mechanisms are provided on the first fluid space side, and the first reservoir groove is provided corresponding to each of the first dynamic pressure mechanisms; A plurality of the second dynamic pressure mechanisms may be provided on the second fluid space side, and the second reservoir groove may be provided corresponding to each of the second dynamic pressure mechanisms. This makes it possible to further suppress interference between the dynamic pressure generated by the first dynamic pressure mechanism and the dynamic pressure generated by the second dynamic pressure mechanism. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a vertical cross-sectional view showing an example of a mechanical seal according to a first embodiment of the present invention. [Figure 2] 3 is an enlarged view of a main part of the sliding surface of the stationary seal ring in the first embodiment, as viewed from the axial direction. FIG. [Figure 3] FIG. 10 is an enlarged view of a main part of a sliding surface of a stationary seal ring according to a second embodiment of the present invention, as viewed from the axial direction. [Figure 4] FIG. 11 is an enlarged view of a main part of a sliding surface of a stationary seal ring according to a third embodiment of the present invention, as viewed from the axial direction. [Figure 5] FIG. 11 is an enlarged view of a main part of a sliding surface of a stationary seal ring according to a fourth embodiment of the present invention, as viewed from the axial direction. [Figure 6] FIG. 11 is an enlarged view of a main part of a sliding surface of a stationary seal ring according to a fifth embodiment of the present invention, as viewed from the axial direction. [Figure 7] FIG. 13 is an enlarged view of a main portion of a sliding surface of a stationary seal ring according to a sixth embodiment of the present invention, as viewed from the axial direction. [Figure 8] FIG. 13 is an enlarged view of a main part of the sliding surface of a stationary seal ring according to a seventh embodiment of the present invention, as viewed from the axial direction. [Figure 9] FIG. 13 is a view of the sliding surface of the stationary seal ring according to the eighth embodiment of the present invention, as viewed from the axial direction. [Figure 10] FIG. 13 is an enlarged view of the sliding surface of the stationary seal ring as viewed from the axial direction when the rotating seal ring rotates forward in the eighth embodiment. [Figure 11] FIG. 13 is an enlarged view of the sliding surface of the stationary seal ring when the rotating seal ring rotates in the reverse direction in the eighth embodiment, as viewed from the axial direction. [Figure 12] FIG. 13 is an enlarged view of a main part of a sliding surface of a stationary seal ring according to a ninth embodiment of the present invention, as viewed from the axial direction. [Figure 13] FIG. 23 is a view of the sliding surface of the stationary seal ring according to the tenth embodiment of the present invention, as viewed from the axial direction. [Figure 14] FIG. 23 is an enlarged view of a main portion of the sliding surface of the stationary seal ring according to the eleventh embodiment of the present invention, as viewed from the axial direction. DETAILED DESCRIPTION OF THE INVENTION

[0019] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A sliding element according to an embodiment of the present invention will be described below with reference to the accompanying drawings. [Example]

[0020] A sliding component according to a first embodiment will be described with reference to FIGS. 1 and 2. In this embodiment, a mechanical seal will be used as an example of the sliding component. The mechanical seal of this embodiment has a first fluid F1, such as oil, in an outer space S1, and a second fluid F2, such as water, in an inner space S2, and prevents the first fluid F1 and the second fluid F2, which are different types, from mixing. For ease of explanation, grooves formed on the sliding surface may be indicated by dots in the drawings.

[0021] 1 is an inside type mechanical seal that seals against a first fluid F1 that attempts to leak from the outer diameter side to the inner diameter side of the sliding surface. That is, an example will be described in which the first fluid F1 is at a higher pressure than the second fluid F2.

[0022] The mechanical seal is mainly composed of a stationary seal ring A and a rotary seal ring 20. The stationary seal ring A is annular and is mounted on a seal cover 5 fixed to a housing 4 of the device to which it is attached in a non-rotating state but movable in the axial direction. The rotary seal ring 20 is annular and is mounted on a rotary shaft 1 via a sleeve 2 so as to be rotatable together with the rotary shaft 1. The stationary seal ring A is axially biased by an elastic member 7. The sliding surface A1 of the stationary seal ring A and the sliding surface 21 of the rotary seal ring 20 slide closely against each other. The sliding surface 21 of the rotary seal ring 20 is flat and does not have any recesses such as grooves on this flat surface.

[0023] The stationary seal ring A and the rotating seal ring 20 are typically formed from 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, or 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. Examples of carbon include a mixture of carbonaceous and graphite, resin-molded carbon, and sintered carbon. In addition to the above sliding materials, metal materials, resin materials, surface-modified materials (coating materials), and composite materials are also applicable.

[0024] 2, the rotary seal ring 20 slides clockwise relative to the stationary seal ring A as shown by the solid arrow. In the following description, the direction of the solid arrow is assumed to be the forward rotation direction of the rotary seal ring 20.

[0025] The sliding surface A1 of the stationary seal ring A is provided with a first pumping mechanism A3 as a first dynamic pressure mechanism, a second pumping mechanism A4 as a second dynamic pressure mechanism, a first annular groove A5 as a first storage groove, and a second annular groove A6 as a second storage groove, and the rest of the surface is made up of land portions A2a, A2b, and A2c.

[0026] The first pumping mechanism A3 is a groove composed of an inclined groove portion A31 that extends from the inner diameter side to the outer diameter side while inclining with a clockwise component, and a circumferential groove portion A32 that extends from the outer diameter end of the inclined groove portion A31 in the forward rotation direction of the rotating seal ring 20.

[0027] The second pumping mechanism A4 is a groove composed of an inclined groove portion A41 that extends from the outer diameter side toward the inner diameter side while inclining with a clockwise component, and a circumferential groove portion A42 that extends from the inner diameter end of the inclined groove portion A41 in the forward rotation direction of the rotating seal ring 20.

[0028] The first annular groove A5 is disposed on the inner diameter side of the first pumping mechanism A3. This first annular groove A5 is formed concentrically with the sliding surface A1 of the stationary seal ring A. The inner diameter end of the inclined groove portion A31 is radially connected to the first annular groove A5.

[0029] The first annular groove A5 is formed to a constant depth in the circumferential direction, and the depth of the first annular groove A5 is deeper than the depth of the first pumping mechanism A3.

[0030] The second annular groove A6 is disposed adjacent to the outer diameter side of the second pumping mechanism A4. This second annular groove A6 is formed concentrically with the sliding surface A1 of the stationary seal ring A. The radial width of the first annular groove A5 and the radial width of the second annular groove A6 may be the same dimension or may be different dimensions. In addition, the outer diameter end of the inclined groove portion A41 is radially connected to the second annular groove A6.

[0031] The second annular groove A6 is formed to a constant depth in the circumferential direction, and the depth of the second annular groove A6 is deeper than the depth of the second pumping mechanism A4. The first annular groove A5 and the second annular groove A6 may have the same depth or different depths.

[0032] Next, a brief description will be given of the flows of the first fluid F1 and the second fluid F2 during relative rotation between the stationary seal ring A and the rotating seal ring 20. Note that the relative rotational speed between the stationary seal ring A and the rotating seal ring 20 will not be specified here.

[0033] First, when the rotary seal ring 20 is not rotating and is at a standstill, the first fluid F1 flows into the first pumping mechanism A3 and the first annular groove A5, and the second fluid F2 flows into the second pumping mechanism A4 and the second annular groove A6.

[0034] Furthermore, since the land portion A2b is disposed between the first annular groove A5 and the second annular groove A6, the first fluid F1 and the second fluid F2 are less likely to mix with each other.

[0035] Furthermore, since the stationary seal ring A is biased toward the rotary seal ring 20 by the elastic member 7, the sliding surfaces A1 and 21 are in contact with each other, and the first fluid F1 and the second fluid F2 are hardly mixed between the sliding surfaces A1 and 21.

[0036] When the rotating seal ring 20 rotates relative to the stationary seal ring A in the positive direction, the first fluid F1 moves in the first pumping mechanism A3 and the first annular groove A5 in response to the relative rotation of the rotating seal ring 20, and the second fluid F2 moves in the second pumping mechanism A4 and the second annular groove A6 in response to the relative rotation of the rotating seal ring 20.

[0037] Specifically, in the first pumping mechanism A3, the first fluid F1 moves from the inner diameter end of the inclined groove portion A31 toward the closed end A32a of the circumferential groove portion A32, thereby generating a slight positive pressure at and near the closed end A32a.

[0038] A portion of the first fluid F1 discharged from the closed end A32a and its vicinity to between the sliding surfaces A1 and 21 flows into the first annular groove A5.

[0039] Since the closed end A32a has an acute angle on the outer diameter side when viewed in the axial direction, a portion of the first fluid F1 discharged from the closed end A32a to between the sliding surfaces A1 and 21 is easily guided to flow into the outer space S1.

[0040] In the second pumping mechanism A4, the second fluid F2 moves from the inner diameter end of the inclined groove A41 toward the closed end A42a of the circumferential groove A42, thereby generating a slight positive pressure at and near the closed end A42a.

[0041] A portion of the second fluid F2 discharged from the closed end A42a and its vicinity to between the sliding surfaces A1 and 21 flows into the second annular groove A6.

[0042] Furthermore, since the closed end A42a has an acute angle on the inner diameter side when viewed in the axial direction, a portion of the second fluid F2 discharged from the closed end A42a to between the sliding surfaces A1 and 21 is easily guided to flow into the internal space S2.

[0043] As described above, the first fluid F1 that flows over the first pumping mechanism A3 toward the inner space S2 is recovered in the first annular groove A5, and the second fluid F2 that flows over the second pumping mechanism A4 toward the outer space S1 is recovered in the second annular groove A6. This prevents the first fluid F1 and the second fluid F2 from mixing between the sliding surfaces A1 and 21, and the first fluid F1 and the second fluid F2 are temporarily stored in the first annular groove A5 and the second annular groove A6, respectively, in a state where mixing is prevented, thereby improving the lubrication effect between the sliding surfaces A1 and 21.

[0044] Furthermore, the dynamic pressure generated by the first pumping mechanism A3 and the dynamic pressure generated by the second pumping mechanism A4 are prevented from interfering with each other due to the first annular groove A5 and the second annular groove A6 that are spaced apart from each other.

[0045] The first pumping mechanism A3 and the first annular groove A5 are in communication with each other, and the second pumping mechanism A4 and the second annular groove A6 are in communication with each other, so that the first fluid F1 and the second fluid F2 can flow between the first pumping mechanism A3 and the first annular groove A5 and between the second pumping mechanism A4 and the second annular groove A6.

[0046] Furthermore, since the first annular groove A5 and the second annular groove A6 are endless annular, the first fluid F1 and the second fluid F2 can be reliably collected over the entire circumference.

[0047] Furthermore, the closed end A32a of the first pumping mechanism A3 has an acute angle on its outer diameter side when viewed in the axial direction, and the closed end A42a of the second pumping mechanism A4 has an acute angle on its inner diameter side when viewed in the axial direction, so that the first fluid F1 can be efficiently returned to the outer space S1 and the second fluid F2 can be efficiently returned to the inner space S2. In this way, mixing of the first fluid F1 and the second fluid F2 can be more effectively prevented, and interference between the dynamic pressures generated by the first pumping mechanism A3 and the second pumping mechanism A4 is less likely to occur.

[0048] Furthermore, since the first annular groove A5 and the second annular groove A6 are spaced apart in the radial direction, interference between the dynamic pressures generated by the first pumping mechanism A3 and the second pumping mechanism A4 is further suppressed.

[0049] Furthermore, since the first annular groove A5 and the second annular groove A6 are annular and arranged concentrically, the first fluid F1 and the second fluid F2 can be easily stored in the first annular groove A5 and the second annular groove A6.

[0050] In this embodiment, the closed end A32a of the first pumping mechanism A3 has an acute angle on the outer diameter side when viewed in the axial direction, and the closed end A42a of the second pumping mechanism A4 has an acute angle on the inner diameter side when viewed in the axial direction, but the shapes of the closed ends of the first pumping mechanism and the second pumping mechanism may be freely changed.

[0051] For example, the inner diameter side of the closed end of the first pumping mechanism and the outer diameter side of the closed end of the second pumping mechanism may form an acute angle when viewed in the axial direction. Also, the closed ends of the first pumping mechanism and the second pumping mechanism may form a right angle or may be arc-shaped.

[0052] In addition, in this embodiment, a configuration is illustrated in which the set of the first pumping mechanism A3 and the first annular groove A5 is connected, and the set of the second pumping mechanism A4 and the second annular groove A6 is connected, but both sets may be disconnected, or only one set may be connected and the other set may be disconnected.

[0053] The first pumping mechanism and the second pumping mechanism may have different shapes and capacities.

[0054] Furthermore, the first pumping mechanism and the second pumping mechanism may be arranged out of phase with each other in the circumferential direction.

[0055] Furthermore, the first and second storage grooves are not limited to being circular when viewed in the axial direction, but may be, for example, polygonal or wave-shaped annular grooves when viewed in the axial direction, or may be C-shaped or comprise multiple arc-shaped grooves in the circumferential direction as shown in Figure 13 described below. [Example]

[0056] Next, a sliding component according to a second embodiment will be described with reference to Fig. 3. Note that a description of the same configuration as in the first embodiment will be omitted. In the following description, the direction of the solid arrow indicates the forward rotation direction of the rotary seal ring 20, and the direction of the dashed arrow indicates the reverse rotation direction of the rotary seal ring 20.

[0057] The first pumping mechanism B3 of the stationary seal ring B of this second embodiment has a first groove B31 as a one-way groove extending in the forward rotation direction of the rotary seal ring 20, and a first reverse groove B32 as a other-way groove extending in the reverse rotation direction of the rotary seal ring 20, and these first groove B31 and first reverse groove B32 are connected to each other.

[0058] The first groove B31 has substantially the same shape as the first pumping mechanism B3 of Example 1. Specifically, the first groove B31 includes an inclined groove portion B31a and a circumferential groove portion B31b.

[0059] The first reverse groove B32 is symmetrical to the first groove B31 with respect to a line LN extending in the radial direction. Specifically, the first reverse groove B32 includes an inclined groove portion B32a and a circumferential groove portion B32b.

[0060] The first groove B31 and the first reverse groove B32 have inclined groove portions B31a and B32a that communicate with each other in the circumferential direction, and their inner diameter ends communicate with the first annular groove B5.

[0061] The second pumping mechanism B4 of the stationary seal ring B in this embodiment 2 includes a second groove B41 as a one-way groove extending in the forward rotation direction of the rotating seal ring 20, and a second reverse groove B42 as an other-way groove extending in the reverse rotation direction of the rotating seal ring 20, and these second groove B41 and second reverse groove B42 are connected to each other.

[0062] The second groove B41 has substantially the same shape as the second pumping mechanism B4 of Example 1. Specifically, the second groove B41 includes an inclined groove portion B41a and a circumferential groove portion B41b.

[0063] The second reverse groove B42 is symmetrical to the second groove B41 with respect to a line LN extending in the radial direction. Specifically, the second reverse groove B42 includes an inclined groove portion B42a and a circumferential groove portion B42b.

[0064] The second groove B41 and the second reverse groove B42 have inclined groove portions B41a and B42a that communicate with each other in the circumferential direction, and their outer diameter ends communicate with the second annular groove B6.

[0065] When the rotary seal ring 20 rotates in the positive direction relative to the stationary seal ring B, the first fluid F1 moves in the first pumping mechanism B3 from the closed end B32c of the circumferential groove portion B32b toward the closed end B31c of the circumferential groove portion B31b, thereby generating a slight positive pressure at and near the closed end B31c and a slight negative pressure at and near the closed end B32c.

[0066] In the second pumping mechanism B4, the second fluid F2 moves from the closed end B42c of the circumferential groove B42b toward the closed end B41c of the circumferential groove B41b, generating a slight positive pressure at and near the closed end B41c and a slight negative pressure at and near the closed end B42c.

[0067] On the other hand, when the rotary seal ring 20 rotates in the opposite direction relative to the stationary seal ring B, the first fluid F1 moves in the first pumping mechanism B3 from the closed end B31c of the circumferential groove portion B31b toward the closed end B32c of the circumferential groove portion B32b, generating a slight positive pressure at and near the closed end B32c and a slight negative pressure at and near the closed end B31c.

[0068] In the second pumping mechanism B4, the second fluid F2 moves from the closed end B41c of the circumferential groove B41b toward the closed end B42c of the circumferential groove B42b, generating a slight positive pressure at and near the closed end B42c and a slight negative pressure at and near the closed end B41c.

[0069] In this way, the first groove B31 and the second groove B41 function to discharge the first fluid F1 and the second fluid F2 during forward rotation of the rotary seal ring 20. On the other hand, during reverse rotation of the rotary seal ring 20, the first reverse groove B32 and the second reverse groove B42 function to discharge the first fluid F1 and the second fluid F2, so that the rotary seal ring 20 can be adapted to both rotation directions.

[0070] Furthermore, since the first groove B31 and the first reverse groove B32 are in communication with each other, the first fluid F1 drawn into one side can be discharged from the other side. Similarly, since the second groove B41 and the second reverse groove B42 are in communication with each other, the second fluid F2 drawn into one side can be discharged from the other side.

[0071] In this embodiment, the first groove B31 and the first reverse groove B32, and the second groove B41 and the second reverse groove B42 are symmetrical with respect to the radially extending line LN. However, asymmetrical shapes may be used, for example, the first groove and the first reverse groove, and the second groove and the second reverse groove may have different shapes or volumes when viewed in the axial direction, or the numbers may be different.

[0072] Furthermore, the first pumping mechanism consisting of the first groove and the first reverse groove and the second pumping mechanism consisting of the second groove and the second reverse groove may have different shapes and volumes when viewed in the axial direction, or may have different quantities. [Example]

[0073] Next, a sliding element according to a third embodiment will be described with reference to Fig. 4. Note that a description of the same configuration as in the second embodiment will be omitted.

[0074] As shown in FIG. 4, in the first pumping mechanism B3' of the third embodiment, the first groove B31' and the first reverse groove B32' are spaced apart in the circumferential direction and are also spaced apart in the radial direction from the first annular groove B5'.

[0075] In the second pumping mechanism B4' of the third embodiment, the second groove B41' and the second reverse groove B42' are spaced apart in the circumferential direction and are also spaced apart in the radial direction from the second annular groove B6.

[0076] The first groove and the first reverse groove may communicate with the first annular groove at a position spaced apart in the radial direction, and the second groove and the second reverse groove may communicate with the second annular groove at a position spaced apart in the radial direction.

[0077] The first groove and the first reverse groove may be spaced apart from each other in the circumferential direction and communicate with the first annular groove, and the second groove and the second reverse groove may be spaced apart from each other in the circumferential direction and communicate with the second annular groove. [Example]

[0078] Next, a sliding element according to a fourth embodiment will be described with reference to Fig. 5. Note that a description of the same configuration as in the second embodiment will be omitted.

[0079] As shown in FIG. 5, the first pumping mechanism B3'' and the second pumping mechanism B4'' are disposed with a circumferential offset. That is, the closed ends B3a'' on both circumferential sides of the first pumping mechanism B3'' and the closed ends B4a'' on both circumferential sides of the second pumping mechanism B4'' (only one side is shown) are disposed with a circumferential offset. In addition, the communication portion between the first pumping mechanism B3'' and the first annular groove B5'', which is a location where the first fluid F1 flows in and out relatively frequently, and the communication portion between the second pumping mechanism B4'' and the second annular groove B6'', which is a location where the second fluid F2 flows in and out relatively frequently, are disposed with a circumferential offset.

[0080] Therefore, the first fluid F1 discharged from the closed end B3a'' of the first pumping mechanism B3'' and the second fluid F2 discharged from the closed end B4a'' of the second pumping mechanism B4'' are unlikely to mix.

[0081] In addition, the first fluid F1 leaking between the sliding surfaces from the communication portion between the first pumping mechanism B3'' and the first annular groove B5'' and the second fluid F2 leaking between the sliding surfaces from the communication portion between the second pumping mechanism B4'' and the second annular groove B6'' are less likely to mix, and the pressure balance generated in the circumferential direction can be improved. [Example]

[0082] Next, a sliding element according to a fifth embodiment will be described with reference to Fig. 6. Note that a description of the same configuration as in the first embodiment will be omitted.

[0083] The sliding surface C1 of the stationary seal ring C is provided with a first pumping mechanism C3, a second pumping mechanism C4, a first annular groove C5, a second annular groove C6, and a third dynamic pressure mechanism C9.

[0084] The third dynamic pressure mechanism C9 includes a radial groove C91 communicating with the outer space S1, and a Rayleigh step C92 as a third dynamic pressure mechanism extending in the forward rotation direction from the inner diameter end of the radial groove C91. Note that the radial groove C91 is formed to the same depth as the Rayleigh step C92, but may be formed to a different depth.

[0085] When the rotating seal ring 20 rotates in the positive direction relative to the stationary seal ring C, in the Rayleigh step C92 of the third dynamic pressure mechanism C9, the first fluid F1 moves to the closed end C92a of the Rayleigh step C92, generating positive pressure at and near the closed end C92a. The force of the positive pressure generated at and near the closed end C92a of the Rayleigh step C92 separates the sliding surfaces C1, 21 from each other, improving lubricity and suppressing wear between the sliding surfaces C1, 21. [Example]

[0086] Next, a sliding element according to a sixth embodiment will be described with reference to Fig. 7. Note that a description of the same configuration as in the fifth embodiment will be omitted.

[0087] A fourth annular groove C8 is provided in the sliding surface C1' of the stationary seal ring C'. The fourth annular groove C8 is provided at a position spaced apart from the outer diameter side of the first annular groove C5'. This fourth annular groove C8 is concentric with the sliding surface C1' of the stationary seal ring C' and is formed to a constant depth in the circumferential direction. The depth of the fourth annular groove C8 may be the same as or different from the depths of the first annular groove C5' and the second annular groove C6'.

[0088] This fourth annular groove C8 has a plurality of (four in this embodiment) communicating grooves C8a arranged in the circumferential direction, each of which extends in the outer diameter direction so as to communicate with the outer space S1. The depth of the communicating grooves C8a is the same as the depth of the fourth annular groove C8.

[0089] According to this, the first fluid F1 flows into the fourth annular groove C8, thereby improving the lubrication effect.

[0090] In addition, since the closed end C3a' of the first pumping mechanism C3' has an acute angle on the outer diameter side when viewed in the axial direction, the first fluid F1 flowing out from the closed end C3a' flows into the fourth annular groove C8 arranged on the outer diameter side of the closed end C3a' and is discharged into the external space S1 through the communicating groove C8a.

[0091] Furthermore, the dynamic pressure generated by the first pumping mechanism C3' and the dynamic pressure generated by the Rayleigh step C92' of the third dynamic pressure mechanism C9' are dispersed by the fourth annular groove C8 provided radially spaced apart, thereby preventing interference with each other. [Example]

[0092] Next, a sliding element according to Example 7 will be described with reference to Fig. 8. Note that a description of the same configuration as in Example 1 will be omitted.

[0093] The sliding surface D1 of the stationary seal ring D is provided with a first pumping mechanism D3, a second pumping mechanism D4, a first annular groove D5, a second annular groove D6, and a third annular groove D7 as an independent pressure release mechanism.

[0094] The third annular groove D7 is formed in a land portion between the first annular groove D5 on the outer diameter side and the second annular groove D6 on the inner diameter side, and is separated from the first annular groove D5 and the second annular groove D6. In other words, a land portion D2a is formed between the first annular groove D5 and the third annular groove D7, and a land portion D2b is formed between the second annular groove D6 and the third annular groove D7.

[0095] The radial width of the third annular groove D7 may be formed to be the same as or different from the radial widths of the first annular groove D5 and the second annular groove D6.

[0096] The third annular groove D7 is concentric with the sliding surface D1 of the stationary seal ring D and is formed to a constant depth in the circumferential direction. The depth of the third annular groove D7 may be the same as or different from the depths of the first annular groove D5 and the second annular groove D6.

[0097] The land portion D2a makes it difficult for the first fluid F1 in the first annular groove D5 to move toward the inner diameter side, and the land portion D2b makes it difficult for the second fluid F2 in the second annular groove 16 to move toward the outer diameter side. In particular, the second fluid F2 on the low-pressure side hardly moves toward the outer diameter side beyond the land portion D2b. Furthermore, the first fluid F1 on the high-pressure side may move slightly toward the inner diameter side beyond the land portion D2a, but is recovered by the third annular groove 17 and is prevented from moving toward the inner diameter side beyond the third annular groove 17.

[0098] In addition, the dynamic pressure generated by the first pumping mechanism D3 and the dynamic pressure generated by the second pumping mechanism D4 are more reliably dispersed and prevented from interfering with each other by the third annular groove D7 formed in the land portion between the first annular groove D5 on the outer diameter side and the second annular groove D6 on the inner diameter side.

[0099] The pressure release mechanism is not limited to an endless annular groove such as a circular groove, and may be a broken line or arc-shaped mechanism. [Example]

[0100] Next, a sliding element according to an eighth embodiment will be described with reference to Figures 9 to 11. Note that a description of the same configuration as in the first embodiment will be omitted.

[0101] As shown in FIG. 9, the sliding surface 11 of the stationary seal ring 10 of this embodiment 8 is provided with a first pumping mechanism 13 as a first dynamic pressure mechanism, a second pumping mechanism 14 as a second dynamic pressure mechanism, a first annular groove 15 as a first storage groove, a second annular groove 16 as a second storage groove, a third annular groove 17 as an independent pressure release mechanism, a fourth annular groove 18 as a circumferential groove, and a third dynamic pressure mechanism 19, and the rest of the surface is made up of land portions 12a, 12b, 12c, 12d, and 12e.

[0102] A plurality of first pumping mechanisms 13 (four in this embodiment) are arranged in the circumferential direction of the sliding surface 11. More specifically, the first pumping mechanisms 13 include a first groove 131 as a one-way groove extending in the forward rotation direction of the rotary seal ring 20, and a first reverse groove 132 as an other-way groove extending in the reverse rotation direction of the rotary seal ring 20, and these first groove 131 and first reverse groove 132 are in communication with each other.

[0103] As shown in Figures 9 and 10, the first groove 131 has an inclined groove portion 131a that extends in an arc shape while inclining with a clockwise component from the inner diameter side toward the outer diameter side, and a circumferential groove portion 131b that extends from the outer diameter end of the inclined groove portion 131a in the forward rotation direction of the rotating seal ring 20.

[0104] The end of circumferential groove 131b in the forward rotation direction is closed end 131c that is inclined toward the outer diameter side. The outer diameter side surface that constitutes circumferential groove 131b is longer in the forward rotation direction than the opposing inner diameter side surface. In other words, closed end 131c forms an acute angle on the outer diameter side and an obtuse angle on the inner diameter side when viewed in the axial direction.

[0105] The first reverse groove 132 has an inclined groove portion 132a that extends in an arc shape while inclining with a counterclockwise component from the inner diameter side toward the outer diameter side, and a circumferential groove portion 132b that extends in the reverse rotation direction of the rotating seal ring 20 from the outer diameter end of the inclined groove portion 132a.

[0106] The end of the circumferential groove 132b in the reverse rotation direction is a closed end 132c that slopes toward the outer diameter side. The outer diameter side surface that constitutes the circumferential groove 132b is longer in the reverse rotation direction than the opposing inner diameter side surface. In other words, the closed end 132c forms an acute angle on the outer diameter side and an obtuse angle on the inner diameter side when viewed in the axial direction.

[0107] The inner diameter ends of the inclined groove portions 131a and 132a communicate with each other in the circumferential direction and also communicate with a first annular groove 15 (described later) in the radial direction. The depths of the first groove 131 and the first reverse groove 132, i.e., the depth of the first pumping mechanism 13, are constant in the circumferential direction.

[0108] The first groove 131 and the first reverse groove 132 are symmetrical with respect to a line LN extending in the radial direction.

[0109] A plurality of second pumping mechanisms 14 (four in this embodiment) are arranged circumferentially on the inner diameter side of sliding surface 11. More specifically, second pumping mechanisms 14 are provided with second grooves 141 as one-way grooves extending in the forward rotation direction of rotary seal ring 20, and second reverse grooves 142 as other-way grooves extending in the reverse rotation direction of rotary seal ring 20, and these second grooves 141 and second reverse grooves 142 are in communication with each other.

[0110] The second groove 141 has an inclined groove portion 141a that extends in an arc shape while inclining with a clockwise component from the outer diameter side toward the inner diameter side, and a circumferential groove portion 141b that extends from the inner diameter end of the inclined groove portion 141a in the forward rotation direction of the rotating seal ring 20.

[0111] The end of circumferential groove 141b in the forward rotation direction is closed end 141c that is inclined toward the inner diameter side. The inner diameter side surface that constitutes circumferential groove 141b is longer in the forward rotation direction than the opposing outer diameter side surface. In other words, closed end 141c forms an acute angle on the inner diameter side and an obtuse angle on the outer diameter side when viewed in the axial direction.

[0112] The second reverse groove 142 has an inclined groove portion 142a that extends in an arc shape while inclining with a counterclockwise component from the outer diameter side toward the inner diameter side, and a circumferential groove portion 142b that extends from the inner diameter end of the inclined groove portion 142a in the reverse rotation direction of the rotating seal ring 20.

[0113] The end of circumferential groove 142b in the reverse rotation direction is closed end 142c that slopes toward the inner diameter side. The inner diameter side of circumferential groove 142b is longer in the reverse rotation direction than the opposing outer diameter side. In other words, closed end 142c forms an acute angle on the inner diameter side and an obtuse angle on the outer diameter side when viewed in the axial direction.

[0114] The inner diameter ends of the inclined groove portions 141a and 142a communicate with each other in the circumferential direction and also communicate with a second annular groove 16 (described later) in the radial direction. The depths of the second groove 141 and the second reverse groove 142, i.e., the depth of the second pumping mechanism 14, are constant in the circumferential direction. In this embodiment, the depths of the first pumping mechanism 13 and the second pumping mechanism 14 are the same.

[0115] The second groove 141 and the second reverse groove 142 are symmetrical with respect to a line LN extending in the radial direction.

[0116] The first annular groove 15 is disposed on the inner diameter side of the first pumping mechanism 13. This first annular groove 15 is formed concentrically with the sliding surface 11 of the stationary seal ring 10. The inner diameter ends of the inclined groove portions 131a, 132a communicate with the first annular groove 15 in the radial direction.

[0117] The first annular groove 15 is formed to a constant depth in the circumferential direction, and the depth of the first annular groove 15 is deeper than the depth of the first pumping mechanism 13.

[0118] Land portions 12a are formed between the first annular groove 15 and the first groove 131, between the first annular groove 15 and the first reverse groove 132, between the first groove 131 and the first reverse groove 132, and between the fourth annular groove 18 (described later) and the first groove 131 and the first reverse groove 132.

[0119] The second annular groove 16 is disposed adjacent to the outer diameter side of the second pumping mechanism 14. The second annular groove 16 is formed concentrically with the sliding surface 11 of the stationary seal ring 10. The radial width of the second annular groove 16 is formed to be the same dimension as the radial width of the first annular groove 15.

[0120] The outer diameter ends of the inclined groove portions 141a, 142a are radially connected to the second annular groove 16. The second annular groove 16 is formed to a constant depth in the circumferential direction, and the depth of the second annular groove 16 is deeper than the depth of the second pumping mechanism 14. The depth of the second annular groove 16 is the same as the depth of the first annular groove 15.

[0121] Land portions 12b are formed on the inner diameter side of the second pumping mechanism 14 between the second annular groove 16 and the second groove 141, between the second annular groove 16 and the second reverse groove 142, and between the second groove 141 and the second reverse groove 142.

[0122] The third annular groove 17 is formed in a land portion between the first annular groove 15 on the outer diameter side and the second annular groove 16 on the inner diameter side, and is separated from the first annular groove 15 and the second annular groove 16. The radial width of the third annular groove 17 is formed to be the same dimension as the radial widths of the first annular groove 15 and the second annular groove 16.

[0123] The third annular groove 17 is concentric with the sliding surface 11 of the stationary seal ring 10 and is formed to a constant depth in the circumferential direction. The depth of the third annular groove 17 is the same as the depths of the first annular groove 15 and the second annular groove 16.

[0124] An annular land portion 12c is formed between the third annular groove 17 and the first annular groove 15, and an annular land portion 12d is formed between the third annular groove 17 and the second annular groove 16 (see FIG. 10 in particular). In this embodiment, the radial width of the land portion 12c and the radial width of the land portion 12d are formed to be the same dimension.

[0125] The fourth annular groove 18 is provided at a position spaced apart from the outer diameter side of the first annular groove 15. This fourth annular groove 18 is concentric with the sliding surface 11 of the stationary seal ring 10 and is formed to a constant depth in the circumferential direction. The depth of the fourth annular groove 18 is the same as the depths of the first to third annular grooves 15 to 17.

[0126] This fourth annular groove 18 has a plurality of (four in this embodiment) communicating grooves 18a arranged in the circumferential direction, extending in the outer diameter direction so as to communicate with the outer space S1. The depth of the communicating grooves 18a is the same as the depth of the fourth annular groove 18.

[0127] The closed ends 131c and 132c of the first pumping mechanism 13 are disposed on the inner diameter side of the communication groove 18a. In other words, the communication groove 18a and the closed ends 131c and 132c overlap in the radial direction.

[0128] A land portion 12e is formed on the outer diameter side of the fourth annular groove 18, excluding the communication groove 18a and a third dynamic pressure mechanism 19, which will be described later.

[0129] The third dynamic pressure mechanism 19 includes a radial groove 191 communicating with the outer space S1, a Rayleigh step 192 as the third dynamic pressure mechanism extending in the forward rotation direction from the inner diameter end of the radial groove 191, and a reverse Rayleigh step 193 as the third dynamic pressure mechanism extending in the reverse rotation direction from the inner diameter end of the radial groove 191. The radial groove 191 is formed to the same depth as the Rayleigh step 192 and the reverse Rayleigh step 193.

[0130] Next, the flows of the first fluid F1 and the second fluid F2 during relative rotation between the stationary seal ring 10 and the rotating seal ring 20 will be explained briefly with reference to Figures 10 and 11. Note that the relative rotational speed between the stationary seal ring 10 and the rotating seal ring 20 will not be specified here.

[0131] First, when the rotating seal ring 20 is stopped and not rotating, the first fluid F1 flows into the fourth annular groove 18, the third dynamic pressure mechanism 19, the first pumping mechanism 13, and the first annular groove 15, and the second fluid F2 flows into the second pumping mechanism 14 and the second annular groove 16.

[0132] In addition, the third annular groove 17 has a land portion 12c and a first annular groove 15 arranged on its outer diameter side, and a land portion 12d and a second annular groove 16 arranged on its inner diameter side, so that the labyrinth effect makes it difficult for the first fluid F1 and the second fluid F2 to flow in.

[0133] Furthermore, since the stationary seal ring 10 is biased toward the rotary seal ring 20 by the elastic member 7, the sliding surfaces 11, 21 are in contact with each other, and the first fluid F1 and the second fluid F2 are hardly mixed between the sliding surfaces 11, 21.

[0134] Next, a state in which the rotary seal ring 20 rotates relative to the stationary seal ring 10 in the forward direction will be described.

[0135] 10, when the rotating seal ring 20 rotates relative to the stationary seal ring 10 in the positive direction, in the Rayleigh step 192 of the third dynamic pressure mechanism 19, the first fluid F1 moves to the closed end 192a of the Rayleigh step 192, generating positive pressure at and near the closed end 192a. The force of the positive pressure generated at and near the closed end 192a of the Rayleigh step 192 separates the sliding surfaces 11, 21, improving lubrication and suppressing wear between the sliding surfaces 11, 21.

[0136] Furthermore, in the inverse Rayleigh step 193, the first fluid F1 moves from the closed end 193a to the radial groove 191, generating a relative negative pressure at the closed end 193a and its vicinity. Therefore, the first fluid F1 around the closed end 193a of the inverse Rayleigh step 193 is sucked in by the relative negative pressure generated at the closed end 193a and its vicinity. Note that the relative negative pressure here does not refer to a vacuum state, but rather to a state where the pressure is lower than the ambient pressure.

[0137] Furthermore, the first fluid F1 that is not sucked into the reverse Rayleigh step 193 flows into the fourth annular groove 18 and is discharged to the outer space S1 via the communication groove 18a.

[0138] In the first pumping mechanism 13, the first annular groove 15, and the fourth annular groove 18, the first fluid F1 moves in accordance with the relative rotation of the rotating seal ring 20, while in the second pumping mechanism 14 and the second annular groove 16, the second fluid F2 moves in accordance with the relative rotation of the rotating seal ring 20.

[0139] Specifically, in the first pumping mechanism 13, the first fluid F1 moves from the closed end 132c of the circumferential groove portion 132b toward the closed end 131c of the circumferential groove portion 131b, which generates a slight positive pressure at and near the closed end 131c, and a slight negative pressure at and near the closed end 132c.

[0140] Therefore, by separating the sliding surfaces 11, 21 from each other by the third dynamic pressure mechanism 19, the first fluid F1 that flows from the outer space S1 across the fourth annular groove 18 to the inner diameter side is sucked by the first pumping mechanism 13. The first fluid F1 sucked by the first pumping mechanism 13 flows toward the closed end 131c, and a portion of it is discharged from the closed end 131c again between the sliding surfaces 11, 21, while the other portion flows into the first annular groove 15.

[0141] Since the closed end 131c has an acute angle on the outer diameter side when viewed in the axial direction, the first fluid F1 flowing out from the closed end 131c to between the sliding surfaces 11 and 21 is easily guided to flow into the communication groove 18a arranged on the outer diameter side of the closed end 131c. Furthermore, the first fluid F1 that does not flow into the communication groove 18a is sucked into the closed end 132c of the first pumping mechanism 13 downstream in the relative rotation.

[0142] Furthermore, the first fluid F1 that is not sucked into the first pumping mechanism 13 and flows further toward the inner diameter side beyond the first pumping mechanism 13 flows into the first annular groove 15. The first fluid F1 that flows into the first annular groove 15 is discharged from the first pumping mechanism 13. More specifically, the first fluid F1 that flows into the first annular groove 15 is guided downstream in the circumferential direction, sucked into the first pumping mechanism 13 on the downstream side, and flows out from its closed end 131c and its vicinity.

[0143] Meanwhile, in the second pumping mechanism 14, the second fluid F2 moves from the closed end 142c of the circumferential groove portion 142b toward the closed end 141c of the circumferential groove portion 141b, thereby generating a slight positive pressure at and near the closed end 141c, and a slight negative pressure at and near the closed end 142c.

[0144] Therefore, when the sliding surfaces 11, 21 are separated from each other by the third dynamic pressure mechanism 19, the second fluid F2 that flows from the internal space S2 into between the sliding surfaces 11, 21 is sucked by the second pumping mechanism 14. The second fluid F2 that is sucked by the second pumping mechanism 14 flows toward the closed end 141c, and a portion of it is discharged from the closed end 141c again between the sliding surfaces 11, 21, while another portion flows into the second annular groove 16.

[0145] Since the closed end 141c has an acute angle on the inner diameter side when viewed in the axial direction, the second fluid F2 flowing out from the closed end 141c to between the sliding surfaces 11 and 21 is easily guided to flow into the internal space S2. In addition, the second fluid F2 that does not flow into the internal space S2 is sucked into the closed end 142c of the second fluid F2 downstream of the relative rotation.

[0146] Furthermore, the second fluid F2 that is not sucked into the second pumping mechanism 14 but flows beyond the second pumping mechanism 14 and further toward the outer diameter side is discharged from the second pumping mechanism 14. Specifically, the second fluid F2 that has flowed into the second annular groove 16 is guided downstream in the circumferential direction, sucked into the downstream second pumping mechanism 14, and flows out from its closed end 141c and its vicinity.

[0147] As described above, the land portion 12c makes it difficult for the first fluid F1 in the first annular groove 15 to move toward the inner diameter side, and the land portion 12d makes it difficult for the second fluid F2 in the second annular groove 16 to move toward the outer diameter side. In particular, the second fluid F2 on the low-pressure side hardly moves toward the outer diameter side of the land portion 12d. Furthermore, the first fluid F1 on the high-pressure side may move slightly toward the inner diameter side of the land portion 12c, but is recovered by the third annular groove 17 and is prevented from moving toward the inner diameter side of the third annular groove 17.

[0148] Next, a state in which the rotary seal ring 20 rotates relative to the stationary seal ring 10 in the opposite direction will be described.

[0149] 11, when the rotating seal ring 20 rotates in the opposite direction relative to the stationary seal ring 10, in the inverse Rayleigh step 193 of the third dynamic pressure mechanism 19, the first fluid F1 moves to the closed end 193a of the inverse Rayleigh step 193, generating positive pressure at and near the closed end 193a. The force of the positive pressure generated at and near the closed end 193a of the inverse Rayleigh step 193 separates the sliding surfaces 11, 21, improving lubrication and suppressing wear between the sliding surfaces 11, 21.

[0150] Furthermore, in the Rayleigh step 192, the first fluid F1 moves from the closed end 192a to the radial groove 191, generating a relative negative pressure at the closed end 192a and in its vicinity. Therefore, the relative negative pressure generated at the closed end 192a of the Rayleigh step 192 and in its vicinity sucks in the first fluid F1 around it.

[0151] Furthermore, the first fluid F1 that is not sucked into the Rayleigh step 192 flows into the fourth annular groove 18 and is discharged to the outer space S1 via the communication groove 18a.

[0152] In the first pumping mechanism 13, the first fluid F1 moves from the closed end 131c of the circumferential groove portion 131b toward the closed end 132c of the circumferential groove portion 132b, thereby generating a slight positive pressure at and near the closed end 132c, and a slight negative pressure at and near the closed end 131c.

[0153] Therefore, by separating the sliding surfaces 11, 21 from each other by the third dynamic pressure mechanism 19, the first fluid F1 that flows from the outer space S1 across the fourth annular groove 18 to the inner diameter side is sucked by the first pumping mechanism 13. The first fluid F1 sucked by the first pumping mechanism 13 flows toward the closed end 132c, and a portion of it is discharged from the closed end 132c again between the sliding surfaces 11, 21, while the other portion flows into the first annular groove 15.

[0154] Since the closed end 132c has an acute angle on the outer diameter side when viewed in the axial direction, the first fluid F1 flowing out from the closed end 132c to between the sliding surfaces 11 and 21 is easily guided to flow into the communication groove 18a arranged on the outer diameter side of the closed end 132c. Furthermore, the first fluid F1 that does not flow into the communication groove 18a is sucked into the closed end 131c of the first pumping mechanism 13 downstream in the relative rotation.

[0155] Furthermore, the first fluid F1 that is not sucked into the first pumping mechanism 13 but flows further toward the inner diameter side beyond the first pumping mechanism 13 is discharged from the first pumping mechanism 13. Specifically, the first fluid F1 that flows into the first annular groove 15 is guided downstream in the circumferential direction, sucked into the downstream first pumping mechanism 13, and flows out from its closed end 132c and its vicinity.

[0156] Meanwhile, in the second pumping mechanism 14, the second fluid F2 moves from the closed end 141c of the circumferential groove portion 141b toward the closed end 142c of the circumferential groove portion 142b, which generates a slight positive pressure at and near the closed end 142c, and a slight negative pressure at and near the closed end 141c.

[0157] Therefore, when the sliding surfaces 11, 21 are separated from each other by the third dynamic pressure mechanism 19, the second fluid F2 that flows from the internal space S2 into between the sliding surfaces 11, 21 is sucked into the second pumping mechanism 14. The second fluid F2 that is sucked into the second pumping mechanism 14 flows toward the closed end 142c, and a portion of it is discharged from the closed end 142c again between the sliding surfaces 11, 21, while the other portion flows into the second annular groove 16.

[0158] Since the closed end 142c has an acute angle on the inner diameter side when viewed in the axial direction, the second fluid F2 flowing out from the closed end 142c to between the sliding surfaces 11 and 21 is easily guided to flow into the internal space S2. In addition, the second fluid F2 that does not flow into the internal space S2 is sucked into the closed end 141c of the second fluid F2 downstream of the relative rotation.

[0159] Furthermore, the second fluid F2 that is not sucked into the second pumping mechanism 14 but flows beyond the second pumping mechanism 14 and further toward the outer diameter side is discharged from the second pumping mechanism 14. Specifically, the second fluid F2 that flows into the second annular groove 16 is guided downstream in the circumferential direction, sucked into the downstream second pumping mechanism 14, and flows out from the closed end 142c and its vicinity.

[0160] As described above, the sliding surface 11 of the stationary seal ring 10 is provided with the first annular groove 15 and the second annular groove 16 via the circumferentially continuous lands 12c, 12d between the first pumping mechanism 13 and the second pumping mechanism 14. With this, the first fluid F1 that flows over the first pumping mechanism 13 toward the inner space S2 is recovered in the first annular groove 15, and the second fluid F2 that flows over the second pumping mechanism 14 toward the outer space S1 is recovered in the second annular groove 16, thereby suppressing mixing of the first fluid F1 and the second fluid F2 between the sliding surfaces 11, 21. As a result, the first fluid F1 and the second fluid F2 are temporarily stored in the first annular groove 15 and the second annular groove 16, respectively, in a state where mixing is prevented, thereby improving the lubrication effect between the sliding surfaces 11, 21.

[0161] Furthermore, since the first annular groove 15 and the second annular groove 16 are provided corresponding to the first pumping mechanism 13 and the second pumping mechanism 14, respectively, mixing of the first fluid F1 and the second fluid F2 is suppressed compared to a single annular groove as in the prior art, and the dynamic pressure generated by the first pumping mechanism 13 and the dynamic pressure generated by the second pumping mechanism 14 are dispersed by the first annular groove 15 and the second annular groove 16, which are provided radially spaced apart, thereby suppressing interference with each other.

[0162] The first pumping mechanism 13 and the first annular groove 15 are in communication, and the second pumping mechanism 14 and the second annular groove 16 are in communication. This allows the first fluid F1 recovered by the first pumping mechanism 13 to be introduced into the first annular groove 15, and the first fluid F1 stored in the first annular groove 15 to be discharged to the first pumping mechanism 13. The second fluid F2 recovered by the second pumping mechanism 14 can be introduced into the second annular groove 16, and the second fluid F2 stored in the second annular groove 16 can be discharged to the second pumping mechanism 14.

[0163] Furthermore, a plurality of first pumping mechanisms 13 communicate with the first annular groove 15, and a plurality of second pumping mechanisms 14 communicate with the second annular groove 16. This allows the first annular groove 15 to recover the first fluid F1 from the first pumping mechanism 13 and to deliver the recovered first fluid F1 to any one of the first pumping mechanisms 13 in the circumferential direction. Similarly, the second annular groove 16 can recover the second fluid F2 from the second pumping mechanism 14 and to deliver the recovered second fluid F2 to any one of the second pumping mechanisms 14 in the circumferential direction.

[0164] Furthermore, the first pumping mechanism 13 and the second pumping mechanism 14 in this embodiment 1 are long in the circumferential direction. Specifically, the first pumping mechanism 13 and the second pumping mechanism 14 are present over approximately 80% or more of the circumferential length of the sliding surface 11, and therefore the first fluid F1 is difficult to guide from the outer space S1 to the first annular groove 15, and the second fluid F2 is difficult to guide from the inner space S2 to the second annular groove 16.

[0165] Furthermore, it is preferable that the first groove 131, the first reverse groove 132, the second groove 141, and the second reverse groove 142 are deeper than the Rayleigh step 192 and the reverse Rayleigh step 193 of the third dynamic pressure mechanism 19, from the viewpoint of ensuring the amount of the first fluid F1 and the second fluid F2 used for lubrication.

[0166] Furthermore, an independent third annular groove 17 is provided in the annular land portion between the first annular groove 15 and the second annular groove 16. With this, even if the first fluid F1 moves beyond the first annular groove 15 toward the inner diameter side, or the second fluid F2 moves beyond the second annular groove 16 toward the outer diameter side, the first fluid F1 and the second fluid F2 can be recovered by the third annular groove 17, thereby further preventing mixing of the first fluid F1 and the second fluid F2. Therefore, interference between the dynamic pressure generating function of the first pumping mechanism 13 and the dynamic pressure generating function of the second pumping mechanism 14 is suppressed.

[0167] In addition, a land portion 12c and a first annular groove 15 are arranged on the outer diameter side of the third annular groove 17, and a land portion 12d and a second annular groove 16 are arranged on the inner diameter side, so that the labyrinth effect makes it difficult for the first fluid F1 and the second fluid F2 to flow in.

[0168] Furthermore, the first pumping mechanism 13 has a first groove 131 extending in the forward rotation direction and a first reverse groove 132 extending in the reverse rotation direction, and the second pumping mechanism 14 has a second groove 141 extending in the forward rotation direction and a second reverse groove 142 extending in the reverse rotation direction. With this, during forward rotation of the rotary seal ring 20, the first groove 131 and the second groove 141 function to discharge the first fluid F1 and the second fluid F2. On the other hand, during reverse rotation of the rotary seal ring 20, the first reverse groove 132 and the second reverse groove 142 function to discharge the first fluid F1 and the second fluid F2, so that the mechanism can accommodate both rotations of the rotary seal ring 20.

[0169] Furthermore, because the first groove 131 and the first reverse groove 132 are in communication, during forward rotation of the rotary seal ring 20, the first fluid F1 sucked into the first reverse groove 132 flows into the first groove 131 and can be discharged from the closed end 131c of the first groove 131 to between the sliding surfaces 11 and 21. During reverse rotation of the rotary seal ring 20, the first fluid F1 sucked into the first groove 131 flows into the first reverse groove 132 and can be discharged from the closed end 132c of the first reverse groove 132 to between the sliding surfaces 11 and 21.

[0170] Furthermore, since the first groove 131 and the first reverse groove 132 are connected in the circumferential direction, the first fluid F1 can flow directly between the first groove 131 and the first reverse groove 132 without going through the first annular groove 15, thereby suppressing the first fluid F1 flowing into the first annular groove 15 and making it less likely for the first fluid F1 to leak from the first annular groove 15 to the inner diameter side.

[0171] Furthermore, because the second groove 141 and the second reverse groove 142 are in communication, during forward rotation of the rotary seal ring 20, the second fluid F2 sucked into the second reverse groove 142 can be made to flow into the second groove 141 and can be discharged from the closed end 141c of the second groove 141 to between the sliding surfaces 11 and 21. During reverse rotation of the rotary seal ring 20, the second fluid F2 sucked into the second groove 141 can be made to flow into the second reverse groove 142 and can be discharged from the closed end 142c of the second reverse groove 142 to between the sliding surfaces 11 and 21.

[0172] Furthermore, since the second groove 141 and the second reverse groove 142 are connected in the circumferential direction, the second fluid F2 can flow directly between the second groove 141 and the second reverse groove 142 without going through the second annular groove 16, thereby suppressing the second fluid F2 flowing into the second annular groove 16 and making it less likely for the second fluid F2 to leak from the second annular groove 16 to the outer diameter side.

[0173] The first groove 131 and the first reverse groove 132 are symmetrical with respect to the line LN extending in the radial direction, and the second groove 141 and the second reverse groove 142 are symmetrical with respect to the line LN extending in the radial direction. This allows the first pumping mechanism 13 and the second pumping mechanism 14 to function in the same manner regardless of the rotational direction of the rotary seal ring 20.

[0174] Furthermore, the first groove 131, the first reverse groove 132, the second groove 141, and the second reverse groove 142 have closed ends 131c, 132c, 142c, and 142c, respectively. In other words, the first groove 131, the first reverse groove 132, the second groove 141, and the second reverse groove 142 are not in communication with the outer space S1 and the inner space S2, so that the flow rates of the first fluid F1 and the second fluid F2 flowing into each groove from the outer space S1 and the inner space S2 can be restricted, and mixing of the first fluid F1 and the second fluid F2 can be prevented while improving the slidability between the sliding surfaces 11, 21.

[0175] The first pumping mechanism 13 has closed ends 131c and 132c that are inclined toward the outer space S1, and the second pumping mechanism 14 has closed ends 141c and 142c that are inclined toward the inner space S2. This allows the first fluid F1 to be discharged from the closed end 131c or 132c of the first pumping mechanism 13 into the outer space S1, while the second fluid F2 to be discharged from the closed end 141c or 142c of the second pumping mechanism 14 into the inner space S2. This allows the first fluid F1 to be efficiently returned to the first fluid space, and the second fluid F2 to be efficiently returned to the second fluid space. This effectively prevents the first fluid F1 and the second fluid F2 from mixing, and reduces interference between the dynamic pressures of the first pumping mechanism 13 and the second pumping mechanism 14.

[0176] Furthermore, a third dynamic pressure mechanism 19 is provided on the sliding surface 11 on the side facing the external space S1, and a fourth annular groove 18 is provided between the third dynamic pressure mechanism 19 and the first pumping mechanism 13. This prevents interference between the dynamic pressure generation function of the third dynamic pressure mechanism 19 and the suction and discharge function of the fourth annular groove 18 for the first fluid F1.

[0177] In this embodiment, the first groove 131 and the first reverse groove 132 are circumferentially connected to each other and to the first annular groove 15, but this is not limited to this, and the first groove and the first reverse groove may be spaced apart circumferentially and connected to the first annular groove.

[0178] Similarly, in this embodiment, an example is given in which the second groove 141 and the second reverse groove 142 are circumferentially connected to each other and to the second annular groove 16, but this is not limited to this, and the second groove and the second reverse groove may be spaced apart circumferentially and connected to the second annular groove. [Example]

[0179] Next, a sliding element according to Example 9 will be described with reference to Fig. 12. Note that a description of the same configuration as in Example 1 will be omitted.

[0180] As shown in FIG. 12, the mechanical seal of the ninth embodiment has a plurality of sets (two sets in the tenth embodiment) of a first dynamic pressure mechanism 913 and a first annular groove 915 as a first storage groove arranged in the radial direction.

[0181] Furthermore, a plurality of sets (two sets in the tenth embodiment) of second dynamic pressure mechanisms 914 and second annular grooves 916 as second storage grooves are provided in the radial direction.

[0182] The number of sets of the first dynamic pressure mechanism 913 and the first annular groove 915 and the number of sets of the second dynamic pressure mechanism 914 and the second annular groove 916 can be freely changed. [Example]

[0183] Next, a sliding element according to a tenth embodiment will be described with reference to Fig. 13. Note that a description of the same configuration as in the first embodiment will be omitted.

[0184] As shown in FIG. 13, in the mechanical seal of Example 10, a first storage groove 2815, a second storage groove 2816, and a pressure release groove 2817 as an independent pressure release mechanism are C-shaped when viewed in the axial direction.

[0185] In this case, it is preferable that the land portion 121 provided between the ends of adjacent first storage grooves 2815, the land portion 122 provided between the ends of adjacent second storage grooves 2816, and the land portion 123 provided between the ends of adjacent pressure release grooves 2817 are arranged circumferentially offset.

[0186] In this embodiment 10, the first storage groove 2815, the second storage groove 2816, and the pressure release groove 2817 are illustrated as being C-shaped when viewed in the axial direction, but they may also be arc-shaped grooves, linear grooves, sinusoidal grooves, or the like, arranged in multiple circumferential directions. The ends of these storage grooves may be tapered, for example. In other words, the storage grooves may have any shape, and the number of grooves may be freely changed. Furthermore, it is preferable that the first storage groove, the second storage groove, and the pressure release groove are provided over a range of at least two-thirds of the length of the sliding surface in the circumferential direction. [Example]

[0187] Next, a sliding element according to an eleventh embodiment will be described with reference to Fig. 14. Note that a description of the same configuration as in the first embodiment will be omitted.

[0188] As shown in FIG. 14, in the mechanical seal of the eleventh embodiment, a first fluid F1 exists in the inner space S2, and a second fluid F2 exists in the outer space S1.

[0189] The sliding surface 811 of the stationary seal ring 810 is provided with a first pumping mechanism 813, a second pumping mechanism 814, a first annular groove 815, a second annular groove 816, a third annular groove 817 and a fourth annular groove 818 as pressure release mechanisms, and a third dynamic pressure mechanism 819.

[0190] The third dynamic pressure mechanism 819 is in communication with the internal space S2. The first pumping mechanism 813 is disposed on the outer diameter side of the third dynamic pressure mechanism 819 at a distance, and a fourth annular groove 818 is provided between the first pumping mechanism 813 and the third dynamic pressure mechanism 819. The fourth annular groove 818 is in communication with the internal space S2 via a plurality of communication grooves 818a.

[0191] A first annular groove 815 is provided on the outer diameter side of the first pumping mechanism 813. The first pumping mechanism 813 and the first annular groove 815 are in communication with each other. A third annular groove 817 is provided on the outer diameter side of the first annular groove 815 at a distance therefrom, and a second annular groove 816 is provided on the outer diameter side of the third annular groove 817 at a distance therefrom.

[0192] A second pumping mechanism 814 is provided on the outer diameter side of the second annular groove 816. The second pumping mechanism 814 and the second annular groove 816 are in communication with each other.

[0193] According to this, when the rotary seal ring 20 rotates relative to the stationary seal ring 810, the first fluid F1 is used to generate dynamic pressure by the third dynamic pressure mechanism 819, and the sliding surfaces can be separated.

[0194] 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.

[0195] For example, in the above-described Examples 1 to 11, mechanical seals have been described as examples of sliding components, but other mechanical seals for general industrial machinery, automobiles, water pumps, etc. may also be used. Furthermore, the sliding components are not limited to mechanical seals, and may be sliding bearings or other sliding components other than mechanical seals.

[0196] In addition, in the above-described Examples 7, 8, 10, and 11, a pressure release mechanism is provided in the land portion between the first reservoir groove and the second reservoir groove on the inner diameter side, but the pressure release mechanism may be omitted. Also, two or more pressure release mechanisms may be provided in the land portion. Furthermore, the pressure release mechanism is not limited to an endless annular groove such as a circular groove, and may be a broken line or arc-shaped groove.

[0197] Furthermore, the first dynamic pressure mechanism and the second dynamic pressure mechanism may be in communication with the first fluid space and the second fluid space.

[0198] Furthermore, in the above-described Examples 1 to 11, a configuration was exemplified in which a slight positive pressure was generated at one end of the first dynamic pressure mechanism and a slight relative negative pressure was generated at the other end of the second dynamic pressure mechanism, but as long as the first dynamic pressure mechanism and the second dynamic pressure mechanism form flows of the first fluid and the second fluid, it is not necessary for positive pressure or relative negative pressure to be generated.

[0199] The third dynamic pressure mechanism may be omitted, particularly when the sliding surfaces can be separated from each other by the positive pressure generated by at least one of the first dynamic pressure mechanism and the second dynamic pressure mechanism.

[0200] Furthermore, the number of first dynamic pressure mechanisms and second dynamic pressure mechanisms may be freely changed.

[0201] Furthermore, in the above-described Examples 1 to 11, the first annular groove and the second annular groove have been illustrated as having a constant depth, but a step or an inclined surface may be formed on the bottom surface of each annular groove.

[0202] In addition, in Examples 1 to 11, the depths of the first and second annular grooves are greater than the depths of the first and second dynamic pressure mechanisms, but they may be the same as or shallower than the depths of the first and second dynamic pressure mechanisms. Note that it is preferable that at least the first and second annular grooves are deeper than the depths of the first and second dynamic pressure mechanisms.

[0203] Furthermore, in the above-described Examples 1 to 11, an annular pressure release mechanism is provided between the third dynamic pressure mechanism and the first dynamic pressure mechanism, but any shape that separates the third dynamic pressure mechanism from the first dynamic pressure mechanism may be used, such as a dashed annular groove or an arc-shaped groove.

[0204] Furthermore, it is not necessary to provide a circumferential groove such as an annular groove or an arc-shaped groove between the third dynamic pressure mechanism and the first dynamic pressure mechanism.

[0205] Furthermore, in the above-described Examples 1 to 11, the third dynamic pressure mechanism is provided on the first fluid space side and generates dynamic pressure using the first fluid, but it may also be provided on the second fluid space side and generate dynamic pressure using the second fluid, or it may be provided on both the first fluid space side and the second fluid space side and generate dynamic pressure using the first fluid and the second fluid.

[0206] In addition, in the above-described Examples 1 to 11, the first fluid is oil and the second fluid is water, but the first fluid and the second fluid may be different fluids. The first fluid and the second fluid are not limited to liquids, and may be gases or a mist formed by mixing liquids and gases.

[0207] Furthermore, in the above-described Examples 1 to 11, the first fluid F1 is at a higher pressure than the second fluid F2, but the first fluid F1 may be at a lower pressure than the second fluid F2 or at substantially the same pressure.

[0208] Furthermore, in the above-described Examples 1 to 11, various grooves are formed on the sliding surface of the stationary seal ring, and the sliding surface of the rotary seal ring is a flat surface, but this is not limiting. Various grooves may be formed on the sliding surface of the rotary seal ring, and the sliding surface of the stationary seal ring may be a flat surface, or various grooves may be formed on the sliding surfaces of the stationary seal ring and the rotary seal ring.

[0209] Furthermore, the shapes of the first dynamic pressure mechanism, the second dynamic pressure mechanism, and the third dynamic pressure mechanism can be freely changed, and may be, for example, a spiral groove, a Rayleigh step, a herringbone shape, or the like. [Explanation of symbols]

[0210] A Stationary seal ring (sliding part) A1 sliding surface A3 First pumping mechanism (first dynamic pressure mechanism) A4 Second pumping mechanism (second dynamic pressure mechanism) A5 First annular groove (first storage groove) A6 Second annular groove (second storage groove) B31 1st groove (one-way groove) B32 1st reverse groove (other direction groove) B41 2nd groove (one-way groove) B42 2nd reverse groove (other direction groove) C9 Third dynamic pressure mechanism D7 3rd annular groove (pressure release mechanism) F1 1st fluid F2 2nd fluid S1 outside space (first fluid space) S2 internal space (second fluid space)

Claims

1. A sliding component in which sliding surfaces of a pair of sliding rings rotate relative to each other to partition a first fluid space and a second fluid space, At least one of the sliding surfaces is a first reservoir groove provided on the first fluid space side and extending in a circumferential direction; a second retention groove extending in a circumferential direction and provided radially separated from the first retention groove on the second fluid space side of the first retention groove; a first dynamic pressure mechanism that is provided closer to the first fluid space than the first storage groove and has a depth shallower than the first storage groove; a second dynamic pressure mechanism that is provided closer to the second fluid space than the second storage groove and has a depth shallower than the second storage groove; A sliding component in which a land portion is formed between the first storage groove and the second storage groove over the entire circumferential direction.

2. 2. The sliding element according to claim 1, wherein at least one of the combinations of the first dynamic pressure mechanism and the first reservoir groove, and the combination of the second dynamic pressure mechanism and the second reservoir groove, is in communication with each other.

3. The sliding element according to claim 1 , wherein at least one of the first reservoir groove and the second reservoir groove is annular.

4. 2. The sliding element according to claim 1, wherein at least one of a closed end inclined toward the first fluid space of the first dynamic pressure mechanism and a closed end inclined toward the second fluid space of the second dynamic pressure mechanism is formed.

5. 3. The sliding element according to claim 2, wherein at least one of a closed end inclined toward the first fluid space of the first dynamic pressure mechanism and a closed end inclined toward the second fluid space of the second dynamic pressure mechanism is formed.

6. 6. The sliding element according to claim 1, wherein at least one of the first dynamic pressure mechanism and the second dynamic pressure mechanism has a one-way groove extending to one side in the circumferential direction and a other-way groove extending to the other side in the circumferential direction.

7. The sliding element according to claim 6, wherein the one-way groove and the other-way groove are in communication with each other.

8. 2. The sliding element according to claim 1, wherein a third dynamic pressure mechanism is provided on at least one side of the first dynamic pressure mechanism on the first fluid space side and the second dynamic pressure mechanism on the second fluid space side.

9. 2. The sliding element according to claim 1, further comprising an independent pressure release mechanism provided between the first reservoir groove and the second reservoir groove.

10. The sliding element according to claim 1 , wherein at least one of the first reservoir groove and the second reservoir groove is annular.

11. a plurality of the first dynamic pressure mechanisms are provided on the first fluid space side, and the first reservoir groove is provided corresponding to each of the first dynamic pressure mechanisms; 2. The sliding element according to claim 1, wherein a plurality of the second dynamic pressure mechanisms are provided on the second fluid space side, and the second reservoir grooves are provided corresponding to the respective second dynamic pressure mechanisms.

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