Sliding member

Abstract

The present invention provides a sliding member capable of suppressing mixing of a first fluid and a second fluid between sliding surfaces. The sliding member is formed such that the sliding surfaces of a pair of sliding rings (10) and (20) rotate relative to each other and define a first fluid space (S1) and a second fluid space (S2), and at least one sliding surface (11) has: a first reservoir groove (15) provided on the first fluid space (S1) side; a second reservoir tank (16) that is provided closer to the second fluid space (S2) than the first reservoir tank (15) and that is provided so as to be separated from the first reservoir tank (15) in the radial direction; a first dynamic pressure mechanism (13) that is provided closer to the first fluid space (S1) than the first reservoir tank (15), and that introduces fluid from the first reservoir tank (15) to generate dynamic pressure; and a second dynamic pressure mechanism (14) that is provided closer to the second fluid space (S2) than the second reservoir tank (16), and that introduces fluid from the second reservoir tank (16) to generate dynamic pressure.

Description

Technical Field

[0001] The invention relates to a sliding component used for shaft seal and bearing. Background Art

[0002] As a sliding component for preventing leakage of a sealed fluid around a rotating shaft in a rotating machine, a mechanical seal composed of a pair of annular sliding rings that slide against each other on relatively rotating sliding surfaces is known. In recent years, in such mechanical seals, it has been required to reduce energy lost due to sliding due to environmental measures and the like, and dynamic pressure generating grooves are sometimes provided on the sliding surfaces of the sliding rings.

[0003] For example, the sliding surface of a sliding ring of a mechanical seal shown in Patent Document 1 is provided with a first negative pressure generating groove and a dynamic pressure generating groove on the inner diameter side, and a second negative pressure generating groove is provided on the outer diameter side. The first negative pressure generating groove is divided by an annular boss into a second fluid space that is not connected to the outer diameter side, and the second negative pressure generating groove is divided by an annular boss into a first fluid space that is not connected to the inner diameter side. The dynamic pressure generating groove is arranged on the inner diameter side of the first negative pressure generating groove. In addition, a 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] When a pair of sliding rings rotate in the positive direction relative to each other, the first fluid on the inner diameter side generates dynamic pressure at the closed end of the dynamic pressure generating groove, thereby slightly separating the sliding surfaces from each other and improving the lubricity between the sliding surfaces. In addition, the first fluid that flows out from the closed end of the dynamic pressure generating groove to between the sliding surfaces is sucked in by the first negative pressure generating groove and discharged to other circumferential grooves. In addition, since the sliding surfaces are separated from each other, the second fluid that flows into the sliding surfaces from the second fluid space on the outer diameter side is attracted by the second negative pressure generating groove and returns to the second fluid space. This prevents the first fluid from flowing into the second fluid space or the second fluid from flowing into the first fluid space, while ensuring the lubricity between the sliding surfaces. Prior art literature Patent Literature

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

[0006] Although 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, there is a risk that the first fluid radially passing through the first negative pressure generating groove or the second fluid radially passing through the second negative pressure generating groove will mix in a circumferential groove between the first negative pressure generating groove and the second negative pressure generating groove arranged between the sliding surfaces.

[0007] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a sliding component capable of suppressing mixing of a first fluid and a second fluid between sliding surfaces. Means of solving problems

[0008] In order to solve the above-mentioned problem, the sliding component of the present invention is a sliding component in which the 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 has: A first storage tank is arranged at the first fluid space side and extends in the circumferential direction; a second storage tank, which is disposed closer to the second fluid space than the first storage tank and is separated from the first storage tank in the radial direction and extends in the circumferential direction; a first dynamic pressure mechanism, which is disposed closer to the first fluid space than the first storage tank and has a shallower depth than the first storage tank; and The second dynamic pressure mechanism is provided on the second fluid space side relative to the second storage tank and has a shallower depth than the second storage tank. Thus, the first fluid flowing toward the second fluid space side over the first dynamic pressure mechanism is recovered in the first storage tank, and the second fluid flowing toward the first fluid space side over the second dynamic pressure mechanism is recovered in the second storage tank, thereby suppressing the first fluid and the second fluid from being mixed between the sliding surfaces. Since the first fluid and the second fluid are temporarily stored in the first storage tank and the second storage tank respectively in a state of preventing mixing, the lubrication effect between the sliding surfaces can be improved. In addition, the first storage tank and the second storage tank provided separately from each other suppress interference between the dynamic pressure generated by the first dynamic pressure mechanism and the dynamic pressure generated by the second dynamic pressure mechanism.

[0009] At least one of a combination of the first dynamic pressure mechanism and the first storage tank and a combination of the second dynamic pressure mechanism and the second storage tank may be in communication. This allows the fluid to flow between the dynamic pressure mechanism and the storage tank in the communicating set.

[0010] At least one of the first storage groove and the second storage groove may be annular. Thus, the first fluid and the second fluid can be reliably recovered over the entire circumference through the first storage tank and the second storage tank.

[0011] At least one of a closed end of the first dynamic pressure mechanism that is inclined toward the first fluid space side and a closed end of the second dynamic pressure mechanism that is inclined toward the second fluid space side may be formed. Thus, the first fluid is led out from the closed end of the first dynamic pressure mechanism to the first fluid space, and the second fluid is led out from the closed end of the second dynamic pressure mechanism to the second fluid space, so that the first fluid can be effectively returned to the first fluid space, and the second fluid can be effectively returned to the second fluid space. In this way, the first fluid and the second fluid can be further prevented from mixing, and the dynamic pressure generated by the first dynamic pressure mechanism and the dynamic pressure generated by the second dynamic pressure mechanism are not easily interfered.

[0012] At least one of the first dynamic pressure mechanism and the second dynamic pressure mechanism may include a one-direction groove extending along one side in the circumferential direction and a another-direction groove extending along the other side in the circumferential direction. Accordingly, when the sliding member relatively rotates in the forward direction, one direction groove can function, and when the sliding member relatively rotates in the reverse direction, the other direction groove can function, thereby being able to accommodate two rotations of the sliding member.

[0013] The one direction groove and the other direction groove may be communicated with each other. This allows the fluid to flow between the one-direction groove and the other-direction groove.

[0014] A third dynamic pressure mechanism may be provided on at least one of a side closer to the first fluid space than the first dynamic pressure mechanism and a side closer to the second fluid space than the second dynamic pressure mechanism. Thus, the sliding surfaces can be easily separated by the third dynamic pressure mechanism, thereby improving the lubrication performance.

[0015] An independent pressure release mechanism may be provided between the first storage tank and the second storage tank. Accordingly, since there is an independent pressure release mechanism between the first storage tank and the second storage tank, the dynamic pressure generated by the first dynamic pressure mechanism and the dynamic pressure generated by the second dynamic pressure mechanism will not interfere with each other. In addition, since the first fluid or the second fluid that radially crosses the first storage tank or the second storage tank can be recovered by the independent pressure release mechanism between the first storage tank and the second storage tank, the first fluid and the second fluid can be further prevented from being mixed.

[0016] At least one of the first storage tank and the second storage tank may be annular. According to this, since no corner is formed in the first storage tank and the second storage tank, no dynamic pressure is generated during relative rotation, and the first fluid and the second fluid can be easily stored in the first storage tank and the second storage tank.

[0017] A plurality of the first dynamic pressure mechanisms may be provided on the first fluid space side, and the first storage tank may be provided corresponding to each of the first dynamic pressure mechanisms. A plurality of the second dynamic pressure mechanisms are provided on the second fluid space side, and a second storage tank is 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 DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a longitudinal sectional view showing an example of a mechanical seal in Example 1 of the present invention. Figure 2 This is an enlarged view of the main parts of the sliding surface of the stationary seal ring in Example 1 as viewed from the axial direction. Figure 3 This is an enlarged view of main parts of the sliding surface of the stationary seal ring in Example 2 of the present invention as viewed from the axial direction. Figure 4 This is an enlarged view of main parts of the sliding surface of the stationary seal ring in Example 3 of the present invention as viewed from the axial direction. Figure 5 This is an enlarged view of main parts of the sliding surface of the stationary seal ring in Example 4 of the present invention as viewed from the axial direction. Figure 6 This is an enlarged view of main parts of the sliding surface of the stationary seal ring in Example 5 of the present invention as viewed from the axial direction. Figure 7 This is an enlarged view of main parts of the sliding surface of the stationary seal ring in Example 6 of the present invention as viewed from the axial direction. Figure 8 This is an enlarged view of main parts of the sliding surface of the stationary seal ring in Example 7 of the present invention as viewed from the axial direction. Fig. 9 This is a diagram showing the sliding surface of a stationary seal ring in Example 8 of the present invention as viewed from the axial direction. Fig.10 This is an enlarged view of the sliding surface of the stationary seal ring when the rotary seal ring in Example 8 rotates in the forward direction, as viewed from the axial direction. Fig.11 This is an enlarged view of the sliding surface of the stationary seal ring when the rotating seal ring in Example 8 rotates in the reverse direction, as viewed from the axial direction. Fig.12 This is an enlarged view of main parts of the sliding surface of the stationary seal ring in Example 9 of the present invention as viewed from the axial direction. Fig.13 This is a diagram showing the sliding surface of the stationary seal ring in Example 10 of the present invention as viewed from the axial direction. Fig.14 This is an enlarged view of main parts of the sliding surface of the stationary seal ring in Example 11 of the present invention, as viewed from the axial direction. DETAILED DESCRIPTION

[0019] Hereinafter, modes for implementing the sliding member of the present invention will be described based on examples. [Example 1]

[0020] Reference Figure 1 as well as Figure 2 The sliding component of Example 1 is described. In this embodiment, a mechanical seal is used as an example of a sliding component. In the mechanical seal of this embodiment, a first fluid F1 such as oil exists in an external space S1, and a second fluid F2 such as water exists in an internal space S2, which prevents the first fluid F1 and the second fluid F2 of different types from mixing. In addition, for the convenience of description, points are sometimes marked on grooves formed on the sliding surface in the figure.

[0021] Figure 1 The mechanical seal shown is an internal mechanical seal that seals the first fluid F1 that easily leaks from the outer diameter side to the inner diameter side of the sliding surface. That is, the example in which the first fluid F1 has a higher pressure than the second fluid F2 is described.

[0022] The mechanical seal is mainly composed of a stationary sealing ring A and a rotating sealing ring 20. The stationary sealing ring A is in the shape of a ring, and is arranged in a non-rotating state and axially movable on a sealing cover 5 fixed to a housing 4 of the installed device. The rotating sealing ring 20 is in the shape of a ring, and is arranged on the rotating shaft 1 through a sleeve 2 so as to be able to rotate together with the rotating shaft 1. The stationary sealing ring A is axially urged by the elastic component 7. The sliding surface A1 of the stationary sealing ring A and the sliding surface 21 of the rotating sealing ring 20 are configured to slide closely with each other. The sliding surface 21 of the rotating sealing ring 20 is a flat surface, and no recessed parts such as grooves are provided on the flat surface.

[0023] The stationary seal ring A and the rotating seal ring 20 are usually formed by a combination of SiC (hard material) or a combination of SiC (hard material) and carbon (soft material), but are not limited to this. As for the sliding material, any sliding material used as a sliding material for mechanical seals can be applied. In addition, as SiC, there are sintered bodies using boron, aluminum, carbon, etc. as sintering aids, and materials having two or more phases with different components and compositions, such as SiC with dispersed graphite particles, reaction sintered SiC composed of SiC and Si, SiC-TiC, SiC-TiN, etc. As carbon, there are carbon mixed with carbon and graphite, and resin molded carbon, sintered carbon, etc. can be used. In addition, in addition to the above-mentioned sliding materials, metal materials, resin materials, surface modification materials (coating materials), composite materials, etc. can also be used.

[0024] like Figure 2As shown, the rotating seal ring 20 slides clockwise relative to the stationary seal ring A, as shown by the solid arrow. The direction of the solid arrow is described below as the positive rotation direction of the rotating seal ring 20.

[0025] 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 are provided on the sliding surface A1 of the stationary sealing ring A, and the rest are boss portions A2a, A2b and A2c.

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

[0027] In addition, the second pumping mechanism A4 is a groove composed of an inclined groove portion A41 and a circumferential groove portion A42, wherein the inclined groove portion A41 is inclined and extends with a clockwise component from the outer diameter side to the inner diameter side, and the circumferential groove portion A42 extends from the inner diameter end of the inclined groove portion A41 toward the positive rotation direction of the rotating sealing ring 20.

[0028] The first annular groove A5 is disposed on the inner diameter side of the first pumping mechanism A3. The 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 communicates with the first annular groove A5 in the radial direction.

[0029] The first annular groove A5 is formed to have 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. The second annular groove A6 is formed concentrically with the sliding surface A1 of the stationary seal ring A. In addition, the radial width of the first annular groove A5 and the radial width of the second annular groove A6 may be the same size or different sizes. In addition, the outer diameter end of the inclined groove portion A41 is connected to the second annular groove A6 in the radial direction.

[0031] Furthermore, the second annular groove A6 is formed to have 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. In addition, the first annular groove A5 and the second annular groove A6 may have the same depth or different depths.

[0032] Next, the flow of the first fluid F1 and the second fluid F2 when the stationary seal ring A and the rotating seal ring 20 rotate relative to each other will be schematically described. Note that the description will be made without determining the relative rotation speed of the stationary seal ring A and the rotating seal ring 20.

[0033] First, when the rotating seal ring 20 stops rotating, 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 boss 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 difficult to mix.

[0035] Furthermore, since the stationary seal ring A is urged toward the rotating 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 sealing ring 20 rotates in the positive direction relative to the stationary sealing ring A, the first fluid F1 in the first pumping mechanism A3 and the first annular groove A5 moves along with the relative rotation of the rotating sealing ring 20. Meanwhile, the second fluid F2 in the second pumping mechanism A4 and the second annular groove A6 moves along with the relative rotation of the rotating sealing 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 peripheral groove portion A32. As a result, a slight positive pressure is generated at the closed end A32a and its vicinity.

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

[0039] Furthermore, since the closed end A32a has an acute angle on the outer diameter side when viewed from 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 external space S1.

[0040] In the second pumping mechanism A4, the second fluid F2 moves from the inner diameter end of the inclined groove portion A41 toward the closed end A42a of the peripheral groove portion A42. As a result, a slight positive pressure is generated at the closed end A42a and its vicinity.

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

[0042] Furthermore, since the closed end A42a is acutely angled on the inner diameter side when viewed from 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 flowing toward the internal space S2 side across the first pumping mechanism A3 is recovered in the first annular groove A5, and the second fluid F2 flowing toward the external space S1 side across the second pumping mechanism A4 is recovered in the second annular groove A6, thereby preventing the first fluid F1 and the second fluid F2 from being mixed between the sliding surfaces A1, 21. Since 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 to prevent mixing, the lubrication effect between the sliding surfaces A1, 21 can be improved.

[0044] In addition, the first annular groove A5 and the second annular groove A6 provided separately from each other suppress interference between the dynamic pressure generated by the first pumping mechanism A3 and the dynamic pressure generated by the second pumping mechanism A4.

[0045] The first pumping mechanism A3 is connected to the first annular groove A5, and the second pumping mechanism A4 is connected to the second annular groove A6, 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 grooves, the first fluid F1 and the second fluid F2 can be reliably recovered over the entire circumference.

[0047] In addition, the closed end A32a of the first pumping mechanism A3 has an acute angle on the outer diameter side when viewed from 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 from the axial direction, thereby enabling the first fluid F1 to be effectively returned to the external space S1, and enabling the second fluid F2 to be effectively returned to the internal space S2. In this way, the first fluid F1 and the second fluid F2 can be further prevented from mixing with each other, and the dynamic pressure generated by the first pumping mechanism A3 and the dynamic pressure generated by the second pumping mechanism A4 are not easily interfered with.

[0048] In addition, since the first annular groove A5 and the second annular groove A6 are provided separately in the radial direction, interference between the dynamic pressure generated by the first pumping mechanism A3 and the dynamic pressure generated by the second pumping mechanism A4 is further suppressed.

[0049] In addition, the first annular groove A5 and the second annular groove A6 are annular and are arranged concentrically, so that 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 addition, in this embodiment, an example is given in which the closed end A32a of the first pumping mechanism A3 is at an acute angle on the outer diameter side when viewed axially, and the closed end A42a of the second pumping mechanism A4 is at an acute angle on the inner diameter side when viewed axially, but the shapes of the respective closed ends of the first pumping mechanism and the second pumping mechanism can be freely changed.

[0051] For example, when viewed from the axial direction, 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 also form an acute angle. In addition, each closed end of the first pumping mechanism and the second pumping mechanism may form a right angle or an arc shape.

[0052] Furthermore, in this embodiment, the first pumping mechanism A3 is connected to the first annular groove A5 group, and the second pumping mechanism A4 is connected to the second annular groove A6 group, but the two groups may not be connected, or only one group may be connected while the other is not connected.

[0053] Note that the shapes and volumes of the first pumping mechanism and the second pumping mechanism may also be different.

[0054] In addition, the first pumping mechanism and the second pumping mechanism may be arranged with their phases shifted from each other in the circumferential direction.

[0055] Furthermore, the first storage groove and the second storage groove are not limited to being annular when viewed from the axial direction, but may also be polygonal or wavy annular grooves when viewed from the axial direction, as described later. Fig.13 As shown, it can also be constructed in a C-shape with multiple arc-shaped grooves in the circumferential direction. [Example 2]

[0056] Next, regarding the sliding member of Example 2, refer to Figure 3 Note that the description of the same structure as that of the first embodiment will be omitted. In the following description, the direction of the solid arrow is described as the forward rotation direction of the rotating seal ring 20, and the direction of the dotted arrow is described as the reverse rotation direction of the rotating seal ring 20.

[0057] The first pumping mechanism B3 of the stationary sealing ring B of this embodiment 2 has a first groove B31 as a one-direction groove extending along the forward rotation direction of the rotating sealing ring 20, and a first reverse groove B32 as the other-direction groove extending along the reverse rotation direction of the rotating sealing ring 20, and these first grooves B31 are connected to the first reverse grooves B32.

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

[0059] The first reverse groove B32 has a shape symmetrical to the first groove B31 about a line LN extending in the radial direction. Specifically, the first reverse groove B32 includes an inclined groove portion B32a and a peripheral groove portion B32b.

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

[0061] The second pumping mechanism B4 of the stationary sealing ring B of this embodiment 2 has a second groove B41 as a one-direction groove extending along the forward rotation direction of the rotating sealing ring 20, and a second reverse groove B42 as the other-direction groove extending along the reverse rotation direction of the rotating sealing ring 20, and these second grooves B41 are connected to the second reverse grooves B42.

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

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

[0064] In the second groove B41 and the second reverse groove B42, the inclined groove portions B41a and B42a are communicated in the circumferential direction, and their outer diameter ends are communicated with the second annular groove B6.

[0065] When the rotating seal ring 20 rotates in the positive direction relative to the stationary seal ring B, in the first pumping mechanism B3, the first fluid F1 moves from the closed end B32c of the peripheral groove portion B32b to the closed end B31c of the peripheral groove portion B32b. As a result, a slight positive pressure is generated at the closed end B31c and its vicinity, and a slight negative pressure is generated at the closed end B32c and its vicinity.

[0066] In the second pumping mechanism B4, the second fluid F2 moves from the closed end B42c of the peripheral groove B42b toward the closed end B41c of the peripheral groove B41b, resulting in a slight positive pressure at the closed end B41c and its vicinity, and a slight negative pressure at the closed end B42c and its vicinity.

[0067] On the other hand, when the rotating seal ring 20 rotates in the opposite direction relative to the stationary seal ring B, the first fluid F1 moves from the closed end B31c of the peripheral groove portion B31b to the closed end B32c of the peripheral groove portion B32b in the first pumping mechanism B3. As a result, a slight positive pressure is generated at the closed end B32c and its vicinity, and a slight negative pressure is generated at the closed end B31c and its vicinity.

[0068] In the second pumping mechanism B4, the second fluid F2 moves from the closed end B41c of the peripheral groove B41b toward the closed end B42c of the peripheral groove B42b, resulting in a slight positive pressure at the closed end B42c and its vicinity, and a slight negative pressure at the closed end B41c and its vicinity.

[0069] Thus, when the rotary seal ring 20 rotates forward, the first groove B31 and the second groove B41 serve to discharge the first fluid F1 and the second fluid F2. On the other hand, when the rotary seal ring 20 rotates reversely, the first reverse groove B32 and the second reverse groove B42 serve to discharge the first fluid F1 and the second fluid F2, thus being able to adapt to two rotations of the rotary seal ring 20.

[0070] In addition, since the first groove B31 and the first reversing groove B32 are connected, the first fluid F1 sucked in one can be discharged from the other. Similarly, since the second groove B41 and the second reversing groove B42 are connected, the second fluid F2 sucked in one can be discharged from the other.

[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 symmetrically shaped with respect to the line LN extending radially, but they may also be asymmetrically shaped. For example, the first groove and the first reverse groove, and the second groove and the second reverse groove may have different shapes and volumes when viewed axially, and may also be different in number.

[0072] In addition, the first pumping mechanism composed of the first groove and the first reverse groove and the second pumping mechanism composed of the second groove and the second reverse groove may have different shapes and volumes when viewed from the axial direction, and the numbers may also be different. [Example 3]

[0073] Next, regarding the sliding member of Example 3, refer to Figure 4 Note that the description of the same structure as that of the second embodiment will be omitted.

[0074] like Figure 4 As shown, in the first pumping mechanism B3' of the present embodiment 3, the first groove B31' and the first reverse groove B32' are separated in the circumferential direction, and are separated from the first annular groove B5' in the radial direction.

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

[0076] In addition, the first groove and the first reverse groove may also be communicated at a position separated from the first annular groove in the radial direction. In addition, the second groove and the second reverse groove may also be communicated at a position separated from the second annular groove in the radial direction.

[0077] In addition, the first groove and the first reverse groove may be communicated with the first annular groove respectively while being separated from each other in the circumferential direction. In addition, the second groove and the second reverse groove may be communicated with the second annular groove respectively while being separated from each other in the circumferential direction. [Example 4]

[0078] Next, regarding the sliding member of Example 4, refer to Figure 5 Note that the description of the same structure as that of the second embodiment will be omitted.

[0079] like Figure 5 As shown, the first pumping mechanism B3" and the second pumping mechanism B4" are staggered in the circumferential direction. That is, the closed ends B3a" on both sides of the circumferential direction of the first pumping mechanism B3" and the closed ends B4a" (only one side is shown) on both sides of the circumferential direction of the second pumping mechanism B4" are staggered in the circumferential direction. In addition, the connecting portion between the first pumping mechanism B3" and the first annular groove B5", which is the place where the first fluid F1 enters and exits more frequently, and the connecting portion between the second pumping mechanism B4" and the second annular groove B6", which is the place where the second fluid F2 enters and exits more frequently, are staggered in the circumferential direction.

[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 difficult to mix.

[0081] In addition, the first fluid F1 leaked from the connecting portion of the first annular groove B5" of the first pumping mechanism B3" to the sliding surfaces and the second fluid F2 leaked from the connecting portion between the second pumping mechanism B4" and the second annular groove B6" to the sliding surfaces are difficult to mix, and the pressure balance generated in the circumferential direction can be improved. [Example 5]

[0082] Next, regarding the sliding member of Example 5, refer to Figure 6 Note that the description of the same structure as that of the first embodiment will be omitted.

[0083] The sliding surface C1 of the stationary sealing 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 external space S1 and a Rayleigh step C92 extending from the inner diameter end of the radial groove C91 in the positive rotation direction as the third dynamic pressure mechanism. Although the radial groove C91 is formed to the same depth as the Rayleigh step C92, they may be formed to different depths.

[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, and a positive pressure is generated at and near the closed end C92a. Since the sliding surfaces C1 and 21 are separated by the force generated by the positive pressure generated at and near the closed end C92a of the Rayleigh step C92, the lubricity is improved, and the wear between the sliding surfaces C1 and 21 can be suppressed. [Example 6]

[0086] Next, regarding the sliding member of Example 6, refer to Figure 7 Note that descriptions of structures that are identical to those of the fifth embodiment are omitted.

[0087] A fourth annular groove C8 is provided on the sliding surface C1' of the stationary sealing ring C'. The fourth annular groove C8 is provided at a position separated from the outer diameter side of the first annular groove C5'. The fourth annular groove C8 is concentric with the sliding surface C1' of the stationary sealing ring C' and is formed to have a constant depth throughout the circumference. In addition, 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] The fourth annular groove C8 has a plurality of (four in this embodiment) communication grooves C8a extending in the outer diameter direction so as to communicate with the external space S1 arranged along the circumferential direction. The depth of the communication grooves C8a is the same as that of the fourth annular groove C8.

[0089] Thus, 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 axially, 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 connecting groove C8a.

[0091] In addition, 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 separated in the radial direction, and the mutual interference is suppressed. [Example 7]

[0092] Next, regarding the sliding member of Example 7, refer to Figure 8 Note that the description of the same structure as that of the first embodiment will be omitted.

[0093] The sliding surface D1 of the stationary sealing 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 the boss 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 boss portion D2a is formed between the first annular groove D5 and the third annular groove D7, and a boss 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 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 has 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 first fluid F1 in the first annular groove D5 is difficult to move to the inner diameter side due to the boss portion D2a, and the second fluid F2 in the second annular groove 16 is difficult to move to the outer diameter side due to the boss portion D2b. In particular, the second fluid F2 on the low-pressure side hardly moves closer to the outer diameter side than the boss portion D2b. In addition, sometimes the first fluid F1 on the high-pressure side moves slightly closer to the inner diameter side than the boss portion D2a, but is recovered by the third annular groove 17 and prevented from moving closer to the inner diameter side than the third annular groove 17.

[0098] In addition, with the help of the third annular groove D7 formed in the boss portion between the first annular groove D5 on the outer diameter side and the second annular groove D6 on the inner diameter side, 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 mutual interference is suppressed.

[0099] In addition, a plurality of pressure release mechanisms may be arranged substantially concentrically. In addition, the pressure release mechanism is not limited to an endless annular groove such as an annular groove, and may also be in the shape of a dotted line or an arc. [Example 8]

[0100] Next, refer to Figures 9 to 11 The sliding member of Example 8 will be described. Note that descriptions of the same structures as those of Example 1 will be omitted.

[0101] like Fig. 9 As shown, the sliding surface 11 of the stationary sealing ring 10 of the present 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, a third dynamic pressure mechanism 19, and the rest are boss portions 12a, 12b, 12c, 12d, and 12e.

[0102] The first pumping mechanism 13 is provided with a plurality of (four in this embodiment) first pumping mechanisms along the circumferential direction of the sliding surface 11. In detail, the first pumping mechanism 13 has a first groove 131 as a one-direction groove extending in the forward rotation direction of the rotating seal ring 20, and a first reverse groove 132 as the other-direction groove extending in the reverse rotation direction of the rotating seal ring 20, and these first grooves 131 and first reverse grooves 132 are connected.

[0103] like Fig. 9 as well as Fig.10 As shown, the first groove 131 has an inclined groove portion 131a and a circumferential groove portion 131b. The inclined groove portion 131a is inclined with a clockwise component from the inner diameter side to the outer diameter side and extends in an arc shape. The circumferential groove portion 131b extends from the outer diameter end of the inclined groove portion 131a to the positive rotation direction of the rotating sealing ring 20.

[0104] The end of the circumferential groove portion 131b in the positive rotation direction is a closed end 131c inclined toward the outer diameter side. The side surface of the outer diameter side of the circumferential groove portion 131b is longer in the positive rotation direction than the side surface of the inner diameter side opposite thereto. That is, when viewed from the axial direction, the outer diameter side of the closed end 131c is an acute angle, and the inner diameter side is an obtuse angle.

[0105] The first reverse groove 132 includes an inclined groove portion 132a and a circumferential groove portion 132b. The inclined groove portion 132a is inclined counterclockwise from the inner diameter side to the outer diameter side and extends in an arc shape. The circumferential groove portion 131b extends from the outer diameter end of the inclined groove portion 131a in the reverse rotation direction of the rotating seal ring 20.

[0106] The end of the circumferential groove portion 132b in the reverse rotation direction is a closed end 132c inclined toward the outer diameter side. The side surface of the outer diameter side of the circumferential groove portion 132b is longer in the reverse rotation direction than the side surface of the inner diameter side opposite thereto. That is, when viewed from the axial direction, the outer diameter side of the closed end 132c is an acute angle, and the inner diameter side is an obtuse angle.

[0107] The inner diameter ends of the inclined groove portions 131a and 132a are connected in the circumferential direction and are radially connected to the first annular groove 15 described later. In addition, 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 have symmetrical shapes with respect to a line LN extending in the radial direction.

[0109] The second pumping mechanism 14 is arranged in a plurality (four in this embodiment) along the inner diameter side circumferential direction of the sliding surface 11. In detail, the second pumping mechanism 14 has a second groove 141 as a one-direction groove extending in the forward rotation direction of the rotating seal ring 20, and a second reverse groove 142 as the other-direction groove extending in the reverse rotation direction of the rotating seal ring 20, and these second grooves 141 and second reverse grooves 142 are connected.

[0110] The second groove 141 includes an inclined groove portion 141a and a circumferential groove portion 141b. The inclined groove portion 141a is inclined with a clockwise component from the outer diameter side to the inner diameter side and extends in an arc shape. The circumferential groove portion 141b extends from the inner diameter end of the inclined groove portion 141a to the positive rotation direction of the rotating seal ring 20.

[0111] The end of the circumferential groove portion 141b in the positive rotation direction is a closed end 141c inclined toward the inner diameter side. The side surface of the inner diameter side of the circumferential groove portion 141b is longer in the positive rotation direction than the side surface of the opposite outer diameter side. That is, when viewed from the axial direction, the inner diameter side of the closed end 141c is an acute angle, and the outer diameter side is an obtuse angle.

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

[0113] The end of the circumferential groove portion 142b in the reverse rotation direction is a closed end 142c inclined toward the inner diameter side. The side surface of the inner diameter side of the circumferential groove portion 142b is longer in the reverse rotation direction than the side surface of the opposite outer diameter side. That is, when viewed from the axial direction, the inner diameter side of the closed end 142c is an acute angle, and the outer diameter side is an obtuse angle.

[0114] The inner diameter end of the inclined groove portion 141a and the inner diameter end of the inclined groove portion 142a are connected in the circumferential direction, and are connected in the radial direction to the second annular groove 16 described later. In addition, the depth of the second groove 141 and the second reverse groove 142, that is, the depth of the second pumping mechanism 14, is a constant depth in the circumferential direction. Note that in this embodiment, the depth of the first pumping mechanism 13 and the depth of the second pumping mechanism 14 are the same depth.

[0115] The second groove 141 and the second reverse groove 142 have symmetrical shapes 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. The first annular groove 15 is formed concentrically with the sliding surface 11 of the stationary seal ring 10. The first annular groove 15 communicates with the inner diameter ends of the inclined groove portions 131a and 132a in the radial direction.

[0117] The first annular groove 15 is formed to have 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] Boss portions 12 a 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 a fourth annular groove 18 described later 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 as the radial width of the first annular groove 15.

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

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

[0122] The third annular groove 17 is formed in a boss portion between the first annular groove 15 on the outer diameter side and the second annular groove 16 on the inner diameter side, and these first annular grooves 15 and second annular grooves 16 are separated. The radial width of the third annular groove 17 is formed to be the same size as the radial width 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 have a constant depth in the circumferential direction. The depth of the third annular groove 17 is the same as the depth of the first annular groove 15 and the second annular groove 16 .

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

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

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

[0127] The closed ends 131c and 132c of the first pumping mechanism 13 are arranged 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 boss portion 12 e is formed on the outer diameter side of the fourth annular groove 18 in a portion excluding the communicating groove 18 a and a third dynamic pressure mechanism 19 described later.

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

[0130] Next, refer to Fig.10 as well as Fig.11 The flow of the first fluid F1 and the second fluid F2 when the stationary seal ring 10 and the rotating seal ring 20 rotate relative to each other is schematically described. Note that the description will be given here without determining the relative rotation speed of the stationary seal ring 10 and the rotating seal ring 20.

[0131] First, when the rotating seal ring 20 stops 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 boss portion 12c and a first annular groove 15 on its outer diameter side, and a boss portion 12d and a second annular groove 16 on its inner diameter side, so that the first fluid F1 and the second fluid F2 are difficult to flow into by means of a labyrinth effect.

[0133] Furthermore, since the stationary seal ring 10 is urged toward the rotating seal ring 20 by the elastic member 7 , the sliding surfaces 11 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 11 and 21 .

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

[0135] like Fig.10 As shown, when the rotating seal ring 20 rotates in the positive direction relative to the stationary seal ring 10, the first fluid F1 moves to the closed end 192a of the Rayleigh step 192 in the third dynamic pressure mechanism 19, and a positive pressure is generated at the closed end 192a and its vicinity. Since the sliding surfaces 11 and 21 are separated by the force generated by the positive pressure generated at the closed end 192a of the Rayleigh step 192 and its vicinity, the lubricity is improved, and the wear between the sliding surfaces 11 and 21 can be suppressed.

[0136] In addition, in the reverse Rayleigh step 193, the first fluid F1 moves from the closed end 193a to the radial groove 191, and a relative negative pressure is generated at and near the closed end 193a. Therefore, the first fluid F1 around it is sucked in by the relative negative pressure generated at and near the closed end 193a of the reverse Rayleigh step 193. Note that the relative negative pressure here refers to a state where the pressure is lower than the surrounding pressure, not a vacuum state.

[0137] In addition, 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 external space S1 through the communication groove 18 a.

[0138] The first fluid F1 moves in the first pumping mechanism 13 and the first and fourth annular grooves 15 and 18 as the rotary seal ring 20 rotates relative to each other, and the second fluid F2 moves in the second pumping mechanism 14 and the second annular groove 16 as the rotary seal ring 20 rotates relative to each other.

[0139] Specifically, in the first pumping mechanism 13, the first fluid F1 moves from the closed end 132c of the peripheral groove 132b toward the closed end 131c of the peripheral groove 131b. As a result, a slight positive pressure is generated at and near the closed end 131c, and a slight negative pressure is generated at and near the closed end 132c.

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

[0141] In addition, when viewed from the axial direction, since the outer diameter side of the closed end 131c is acutely angled, 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 connecting groove 18a arranged on the outer diameter side of the closed end 131c. In addition, the first fluid F1 that does not flow into the connecting groove 18a is sucked into the closed end 132c of the first pumping mechanism 13 on the relatively rotation downstream side.

[0142] In addition, 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 has flowed into the first annular groove 15 is discharged from the first pumping mechanism 13. In detail, the first fluid F1 that has flowed into the first annular groove 15 is guided toward the circumferential downstream side, is sucked into the first pumping mechanism 13 on the downstream side, and flows out from the closed end 131c thereof and its vicinity.

[0143] On the other hand, in the second pumping mechanism 14, the second fluid F2 moves from the closed end 142c of the peripheral groove 142b toward the closed end 141c of the peripheral groove 141b. As a result, a slight positive pressure is generated at and near the closed end 141c, and a slight negative pressure is generated at and near the closed end 142c.

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

[0145] In addition, since the inner diameter side of the closed end 141c is acutely angled when viewed from 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 on the downstream side of the relative rotation.

[0146] In addition, the second fluid F2 that is not sucked into the second pumping mechanism 14 but flows to the outer diameter side over the second pumping mechanism 14 is discharged from the second pumping mechanism 14. In detail, the second fluid F2 that flows into the second annular groove 16 is guided to the circumferential downstream side, is sucked into the second pumping mechanism 14 on the downstream side, and flows out from the closed end 141c and its vicinity.

[0147] In addition, as described above, the first fluid F1 in the first annular groove 15 is difficult to move to the inner diameter side due to the boss portion 12c, and the second fluid F2 in the second annular groove 16 is difficult to move to the outer diameter side due to the boss portion 12d. In particular, the second fluid F2 on the low-pressure side hardly moves to the outer diameter side than the boss portion 12d. In addition, sometimes the first fluid F1 on the high-pressure side moves slightly to the inner diameter side than the boss portion 12c, but is recovered by the third annular groove 17 and prevented from moving to the inner diameter side than the third annular groove 17.

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

[0149] like Fig.11 As shown, when the rotating seal ring 20 rotates in the opposite direction relative to the stationary seal ring 10, the first fluid F1 moves toward the closed end 193a of the reverse Rayleigh step 193 in the third dynamic pressure mechanism 19, and a positive pressure is generated at the closed end 193a and its vicinity. Since the sliding surfaces 11 and 21 are separated by the force generated by the positive pressure generated at the closed end 193a of the reverse Rayleigh step 193 and its vicinity, the lubricity is improved, and the wear between the sliding surfaces 11 and 21 can be suppressed.

[0150] In addition, in the Rayleigh step 192, the first fluid F1 moves from the closed end 192a to the radial groove 191, and a relative negative pressure is generated at and near the closed end 192a. Therefore, by virtue of the relative negative pressure generated at and near the closed end 192a of the Rayleigh step 192, the first fluid F1 around it is sucked in.

[0151] In addition, 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 external space S1 through the communication groove 18 a.

[0152] In the first pumping mechanism 13, the first fluid F1 moves from the closed end 131c of the peripheral groove 131b toward the closed end 132c of the peripheral groove 132b. As a result, a slight positive pressure is generated at and near the closed end 132c, and a slight negative pressure is generated at and near the closed end 131c.

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

[0154] In addition, when viewed from the axial direction, since the outer diameter side of the closed end 132c is acutely angled, 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 connecting groove 18a arranged on the outer diameter side of the closed end 132c. In addition, the first fluid F1 that does not flow into the connecting groove 18a is sucked into the closed end 131c of the first pumping mechanism 13 on the relatively rotation downstream side.

[0155] In addition, the first fluid F1 that is not sucked into the first pumping mechanism 13 but flows toward the inner diameter side over the first pumping mechanism 13 is discharged from the first pumping mechanism 13. In detail, the first fluid F1 that has flowed into the first annular groove 15 is guided toward the circumferential downstream side, is sucked into the first pumping mechanism 13 on the downstream side, and flows out from the closed end 132c and its vicinity.

[0156] On the other hand, in the second pumping mechanism 14, the second fluid F2 moves from the closed end 141c of the peripheral groove 141b toward the closed end 142c of the peripheral groove 142b. As a result, a slight positive pressure is generated at the closed end 142c and its vicinity, and a slight negative pressure is generated at the closed end 141c and its vicinity.

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

[0158] In addition, since the inner diameter side of the closed end 142c is acutely angled when viewed from 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 on the downstream side of the relative rotation.

[0159] In addition, the second fluid F2 that is not sucked into the second pumping mechanism 14 and flows to the outer diameter side over the second pumping mechanism 14 is discharged from the second pumping mechanism 14. In detail, the second fluid F2 that has flowed into the second annular groove 16 is guided to the circumferential downstream side, is sucked into the second pumping mechanism 14 on the downstream side, 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 via the boss portions 12c and 12d which are continuous in the circumferential direction between the first pumping mechanism 13 and the second pumping mechanism 14. Thus, the first fluid F1 which flows toward the inner space S2 side over the first pumping mechanism 13 is recovered in the first annular groove 15, and the second fluid F2 which flows toward the outer space S1 side over the second pumping mechanism 14 is recovered in the second annular groove 16, thereby suppressing the first fluid F1 and the second fluid F2 from being mixed between the sliding surfaces 11 and 21. As a result, since 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 of preventing mixing, the lubrication effect between the sliding surfaces 11 and 21 can be improved.

[0161] In addition, since the first annular groove 15 and the second annular groove 16 are respectively arranged corresponding to the first pumping mechanism 13 and the second pumping mechanism 14, the mixing of the first fluid F1 and the second fluid F2 is suppressed compared with the single annular groove 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 means of the first annular groove 15 and the second annular groove 16 that are separately arranged, thereby suppressing mutual interference.

[0162] In addition, the first pumping mechanism 13 is connected to the first annular groove 15, and the second pumping mechanism 14 is connected to the second annular groove 16. Thus, the first fluid F1 recovered by the first pumping mechanism 13 can be introduced into the first annular groove 15, and the first fluid F1 stored in the first annular groove 15 can be exported to the first pumping mechanism 13. In addition, the second fluid F2 recovered by the first 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 exported to the second pumping mechanism 14.

[0163] Furthermore, a plurality of first pumping mechanisms 13 are connected to the first annular groove 15, and a plurality of second pumping mechanisms 14 are connected to the second annular groove 16. Thus, the first annular groove 15 can recover the first fluid F1 from the first pumping mechanism 13, and can guide the recovered first fluid F1 to any first pumping mechanism 13 in the circumferential direction. Thus, the second annular groove 16 can also recover the second fluid F2 from the second pumping mechanism 14, and can guide the recovered second fluid F2 to any second pumping mechanism 14 in the circumferential direction.

[0164] In addition, the first pumping mechanism 13 and the second pumping mechanism 14 in the present embodiment 1 are longer in the circumferential direction. Specifically, since the first pumping mechanism 13 and the second pumping mechanism 14 exist at approximately 80% or more of the circumferential length of the sliding surface 11, it is difficult for the first fluid F1 to be guided from the external space S1 to the first annular groove 15, and it is difficult for the second fluid F2 to be guided from the internal space S2 to the second annular groove 16.

[0165] In addition, from the viewpoint of ensuring the amount of the first fluid F1 and the second fluid F2 for lubrication, the first groove 131 , the first reversing groove 132 , the second groove 141 , and the second reversing groove 142 are preferably deeper than the Rayleigh step 192 and the reverse Rayleigh step 193 of the third dynamic pressure mechanism 19 .

[0166] In addition, an independent third annular groove 17 is provided in the annular boss portion between the first annular groove 15 and the second annular groove 16. Thus, even if the first fluid F1 moves to the outer diameter side across the first annular groove 15, or the second fluid F2 moves to the outer diameter side across the second annular groove 16, the first fluid F1 and the second fluid F2 can be further prevented from being mixed because they can be recovered in the third annular groove 17. 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] Furthermore, since the boss 12c and the first annular groove 15 are arranged on the outer diameter side of the third annular groove 17 and the boss 12d and the second annular groove 16 are arranged on the inner diameter side thereof, the first fluid F1 and the second fluid F2 are difficult to flow into due to the labyrinth effect.

[0168] In addition, the first pumping mechanism 13 includes 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. Accordingly, when the rotating seal ring 20 rotates forward, the first groove 131 and the second groove 141 play a role in discharging the first fluid F1 and the second fluid F2. On the other hand, when the rotating seal ring 20 rotates reversely, the first reverse groove 132 and the second reverse groove 142 can play a role in discharging the first fluid F1 and the second fluid F2, so that it can adapt to two rotations of the rotating seal ring 20.

[0169] In addition, since the first groove 131 and the first reverse groove 132 are connected to each other, when the rotary seal ring 20 rotates forward, the first fluid F1 sucked into the first reverse groove 132 can flow into the first groove 131, and the first fluid F1 is discharged from the closed end 131c of the first groove 131 to between the sliding surfaces 11 and 21. In addition, when the rotary seal ring 20 rotates reversely, the first fluid F1 sucked into the first groove 131 can flow into the first reverse groove 132, and the first fluid F1 is discharged from the closed end 132c of the first reverse groove 132 to between the sliding surfaces 11 and 21.

[0170] In addition, 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 passing through the first annular groove 15, so the first fluid F1 can be prevented from flowing into the first annular groove 15, making it difficult for the first fluid F1 to leak from the first annular groove 15 to the inner diameter side.

[0171] In addition, since the second groove 141 and the second reverse groove 142 are connected to each other, when the rotary seal ring 20 rotates forward, the second fluid F2 sucked into the second reverse groove 142 can flow into the second groove 141, and the second fluid F2 is discharged from the closed end 141c of the second groove 141 to between the sliding surfaces 11 and 21. In addition, when the rotary seal ring 20 rotates reversely, the second fluid F2 sucked into the second groove 141 can flow into the second reverse groove 142, and the second fluid F2 is discharged from the closed end 142c of the second reverse groove 142 to between the sliding surfaces 11 and 21.

[0172] In addition, 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 passing through the second annular groove 16, so the second fluid F2 can be prevented from flowing into the second annular groove 16, making it difficult for the second fluid F2 to leak from the second annular groove 16 to the outer diameter side.

[0173] In addition, the first groove 131 and the first reverse groove 132 are symmetrically shaped with respect to the line LN extending in the radial direction, and the second groove 141 and the second reverse groove 142 are symmetrically shaped with respect to the line LN extending in the radial direction. Thus, the first pumping mechanism 13 and the second pumping mechanism 14 can function in the same manner regardless of the rotation direction of the rotating seal ring 20.

[0174] In addition, 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, since the first groove 131, the first reverse groove 132, the second groove 141, and the second reverse groove 142 are not connected to the external space S1 and the internal space S2, the flow rate of the first fluid F1 and the second fluid F2 flowing into each groove from the external space S1 and the internal space S2 can be limited, and the first fluid F1 and the second fluid F2 can be prevented from mixing, while the sliding property between the sliding surfaces 11 and 21 is increased.

[0175] In addition, the first pumping mechanism 13 is formed with closed ends 131c and 132c inclined toward the external space S1, and the second pumping mechanism 14 is formed with closed ends 141c and 142c inclined toward the internal space S2. Thus, since the first fluid F1 is exported from the closed end 131c or the closed end 132c of the first pumping mechanism 13 to the external space S1, and the second fluid F2 is exported from the closed end 141c or the closed end 142c of the second pumping mechanism 13 to the internal space S2, 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, the first fluid F1 and the second fluid F2 can be further prevented from mixing, and the dynamic pressure generated by the first pumping mechanism 13 and the dynamic pressure generated by the second pumping mechanism 14 are not easily interfered.

[0176] In addition, a third dynamic pressure mechanism 19 is provided on the outer space S1 side of the sliding surface 11, and a fourth annular groove 18 is provided between the third dynamic pressure mechanism 19 and the first pumping mechanism 13. Thus, it is possible to prevent the dynamic pressure generating function of the third dynamic pressure mechanism 19 and the suction and discharge function of the fourth annular groove 18 on the first fluid F1 from interfering with each other.

[0177] In addition, in this embodiment, an example is given in which the first groove 131 and the first reverse groove 132 are connected to each other in the circumferential direction and connected to the first annular groove 15, but it is not limited to this. The first groove and the first reverse groove can also be separated in the circumferential direction and connected to the first annular groove.

[0178] Similarly, in this embodiment, an example is given of the first groove 141 and the first reverse groove 142 being connected to each other in the circumferential direction and connected to the second annular groove 16, but it is not limited to this. The second groove and the second reverse groove may also be separated in the circumferential direction and connected to the second annular groove. [Example 9]

[0179] Next, regarding the sliding member of Example 9, refer to Fig.12 Note that the description of the same structure as that of the first embodiment will be omitted.

[0180] like Fig.12 As shown, the mechanical seal of the ninth embodiment is provided with a plurality of sets (two sets in the tenth embodiment) of first dynamic pressure mechanisms 913 and a first annular groove 915 as a first storage groove in the radial direction.

[0181] In addition, a plurality of sets (two sets in the present embodiment 10) of second dynamic pressure mechanisms 914 and second annular grooves 916 serving as second storage grooves are provided in the radial direction.

[0182] In addition, 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 10]

[0183] Next, regarding the sliding member of Example 10, refer to Fig.13 Note that the description of the same structure as that of the first embodiment will be omitted.

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

[0185] In this case, the boss portion 121 provided between the ends of adjacent first storage grooves 2815, the boss portion 122 provided between the ends of adjacent second storage grooves 2816, and the boss portion 123 provided between the ends of adjacent pressure release grooves 2817 are preferably arranged staggered in the circumferential direction.

[0186] In the present embodiment 10, the first storage groove 2815, the second storage groove 2816 and the pressure release groove 2817 are exemplified as being C-shaped when viewed from the axial direction, but it can also be a plurality of arc-shaped grooves, linear grooves, sine-wave grooves, etc. arranged in the circumferential direction. In addition, the ends of these storage grooves can also be tapered at the top, etc. That is, the storage grooves can be of any shape and the number can be freely changed. In addition, it is preferred that the first storage groove, the second storage groove and the pressure release groove are arranged in a range of more than two-thirds of the length of the sliding surface in the circumferential direction. [Example 11]

[0187] Next, regarding the sliding member of Example 11, refer to Fig.14 Note that the description of the same structure as that of the first embodiment will be omitted.

[0188] like Fig.14 As shown, in the mechanical seal of the present embodiment 11, the first fluid F1 exists in the internal space S2, and the second fluid F2 exists in the external space S1.

[0189] The sliding surface 811 of the stationary sealing 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 as a pressure release mechanism, a fourth annular groove 818 , and a third dynamic pressure mechanism 819 .

[0190] The third dynamic pressure mechanism 819 is connected to the internal space S2. The first pumping mechanism 813 is separated from the outer diameter side of the third dynamic pressure mechanism 819, 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 connected to the internal space S2 through a plurality of connecting grooves 818a.

[0191] The first pumping mechanism 813 is provided with a first annular groove 815 on its outer diameter side. The first pumping mechanism 813 is connected to the first annular groove 815. In addition, a third annular groove 817 is provided separately on its outer diameter side, and a second annular groove 816 is provided separately on its outer diameter side.

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

[0193] According to this, when the rotating seal ring 20 rotates relative to the stationary seal ring 810 , dynamic pressure is generated by the first fluid F1 through the third dynamic pressure mechanism 819 , so that the sliding surfaces can be separated.

[0194] As mentioned above, although the embodiments of the present invention are described with reference to the drawings, the specific configuration is not limited to these embodiments, and any changes or additions that do not depart from the gist of the present invention are also included in the present invention.

[0195] For example, in the above-mentioned embodiments 1 to 11, mechanical seals are used as examples of sliding parts, but they may be other mechanical seals for general industrial machinery, automobiles, water pumps, etc. In addition, they are not limited to mechanical seals, and may be sliding parts other than mechanical seals such as sliding bearings.

[0196] In addition, in the above-mentioned Embodiment 7, Embodiment 8, Embodiment 10, and Embodiment 11, although the example of providing a pressure release mechanism in the boss portion between the first storage groove and the second storage groove on the inner diameter side is described, the structure of the pressure release mechanism may be omitted. In addition, two or more pressure release mechanisms may be provided in the boss portion. In addition, the pressure release mechanism is not limited to an endless annular groove such as an annular groove, and may also be a dotted line shape or an arc shape. 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] In addition, in the embodiments 1 to 11, examples are given of a method in which a slight positive pressure is generated on one end side and a slight relative negative pressure is generated on the other end side in the first dynamic pressure mechanism and the second dynamic pressure mechanism. However, as long as the flow of the first fluid and the second fluid is formed by the first dynamic pressure mechanism and the second dynamic pressure mechanism, positive pressure and relative negative pressure do not have to be generated.

[0199] In addition, the structure of the third dynamic pressure mechanism may be omitted. In particular, if the sliding surfaces can be separated from each other by the positive pressure generated in at least one of the first dynamic pressure mechanism or the second dynamic pressure mechanism, the structure of the third dynamic pressure mechanism may be omitted.

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

[0201] In the above-mentioned embodiments 1 to 11, an example is given in which the depths of the first annular groove and the second annular groove are constant. However, a step or an inclined surface may be formed on the bottom surface of each annular groove.

[0202] In addition, in the embodiments 1 to 11, the first annular groove and the second annular groove are described as having a depth deeper than the first dynamic pressure mechanism and the second dynamic pressure mechanism, but the depth may be the same as the depth of the first dynamic pressure mechanism and the second dynamic pressure mechanism, or may be shallower than the depth of the first dynamic pressure mechanism and the second dynamic pressure mechanism. In addition, it is preferred that at least the first annular groove and the second annular groove are deeper than the first dynamic pressure mechanism and the second dynamic pressure mechanism.

[0203] In addition, in the embodiments 1 to 11, an example is given of a method in which an annular pressure release mechanism is provided between the third dynamic pressure mechanism and the first dynamic pressure mechanism, but any shape that divides the third dynamic pressure mechanism and the first dynamic pressure mechanism will suffice, for example, it may be a dotted annular groove, an arc-shaped groove, etc.

[0204] In addition, a circumferential groove such as an annular groove or an arc-shaped groove may not be provided between the third dynamic pressure mechanism and the first dynamic pressure mechanism.

[0205] In addition, in the embodiments 1 to 11, the third dynamic pressure mechanism is illustrated as being arranged on the first fluid space side and using the first fluid to generate dynamic pressure, but it can also be arranged on the second fluid space side and use the second fluid to generate dynamic pressure, or it can also be arranged on both the first fluid space side and the second fluid space side and use the first fluid and the second fluid to generate dynamic pressure.

[0206] In addition, in the embodiments 1 to 11, the first fluid is oil and the second fluid is water, but they can be freely changed as long as the first fluid and the second fluid are different fluids. In addition, the first fluid and the second fluid are not limited to liquids, but can also be gases, or mists of a mixture of liquid and gas.

[0207] In the above-described embodiments 1 to 11, the pressure of the first fluid F1 is higher than the pressure of the second fluid F2. However, the first fluid F1 may have a lower pressure than the second fluid F2, or may have substantially the same pressure.

[0208] In addition, in the embodiments 1 to 11, examples are given in which the sliding surface of the stationary sealing ring is formed with various grooves, and the sliding surface of the rotating sealing ring is a flat surface, but the present invention is not limited to this. The sliding surface of the rotating sealing ring may also be formed with various grooves, the sliding surface of the stationary sealing ring may also be a flat surface, or various grooves may be formed on the sliding surfaces of the stationary sealing ring and the rotating sealing 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, for example, they can be spiral grooves, Rayleigh steps, herringbone shapes, etc. Description of Reference Numerals

[0210] A Stationary sealing 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 ring groove (second storage groove) B31 first slot (one direction slot) B32 first reverse groove (the other direction groove) B41 second slot (one direction slot) B42 second reverse groove (the other direction groove) C9 third dynamic pressure mechanism D7 third ring groove (pressure release mechanism) F1 First Fluid F2 Second Fluid S1 external space (first fluid space) S2 internal space (second fluid space)

Claims

1. A sliding component, wherein the sliding surfaces of a pair of sliding rings rotate relative to each other and divide a first fluid space and a second fluid space, characterized in that: At least one of the sliding surfaces has: A first storage tank is arranged on the first fluid space side and extends in the circumferential direction; a second storage tank, which is disposed closer to the second fluid space than the first storage tank and is separated from the first storage tank in the radial direction and extends in the circumferential direction; A first dynamic pressure mechanism is disposed closer to the first fluid space than the first storage tank and has a shallower depth than the first storage tank; as well as The second dynamic pressure mechanism is provided on the second fluid space side relative to the second storage tank and has a shallower depth than the second storage tank.

2. The sliding component according to claim 1, characterized in that At least one of a combination of the first dynamic pressure mechanism and the first storage tank and a combination of the second dynamic pressure mechanism and the second storage tank is in communication with each other.

3. The sliding component according to claim 1, characterized in that: At least one of the first storage tank and the second storage tank is annular.

4. The sliding component according to claim 1, characterized in that: 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 is formed.

5. The sliding component according to claim 2, characterized in that: 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 is formed.

6. The sliding component according to any one of claims 1 to 5, characterized in that: At least one of the first dynamic pressure mechanism and the second dynamic pressure mechanism has a one-direction groove extending along one side in the circumferential direction and a other-direction groove extending along the other side in the circumferential direction.

7. The sliding component according to claim 6, characterized in that The one direction groove is communicated with the other direction groove.

8. The sliding component according to claim 1, characterized in that: A third dynamic pressure mechanism is provided at least on one side closer to the first fluid space than the first dynamic pressure mechanism and on one side closer to the second fluid space than the second dynamic pressure mechanism.

9. The sliding component according to claim 1, characterized in that: An independent pressure release mechanism is provided between the first storage tank and the second storage tank.

10. The sliding component according to claim 1, characterized in that At least one of the first storage tank and the second storage tank is annular.

11. The sliding component according to claim 1, characterized in that: A plurality of the first dynamic pressure mechanisms are provided on the first fluid space side, and a first storage tank is provided corresponding to each of the first dynamic pressure mechanisms. A plurality of the second dynamic pressure mechanisms are provided on the second fluid space side, and a second storage tank is provided corresponding to each of the second dynamic pressure mechanisms.

Images