Sliding member

Abstract

Provided is a sliding member capable of preventing poor lubrication between sliding surfaces when relative rotation is at a low speed. In a sliding member in which a pair of sliding rings (10, 20) rotate relative to each other and define a first fluid space (S1) and a second fluid space (S2), the sliding surfaces (10, 20) of the pair of sliding rings have: a specific dynamic pressure generation groove (16) which is provided on the first fluid space (S1) side and which generates dynamic pressure by means of a first fluid (F); a dynamic pressure generation groove (15) that is provided closer to the second fluid space (S2) than the specific dynamic pressure generation groove (16) and generates dynamic pressure by means of the second fluid (A); a communication groove (131) that communicates with the first fluid space (S1); a circumferential groove (132) that is provided closer to the second fluid space (S1) than the specific dynamic pressure generation groove (16) and that extends in the circumferential direction from the communication groove (131); and a first fluid introduction groove (14) which is provided closer to the second fluid space (S2) than the circumferential groove (132) and into which the first fluid (F) is introduced.

Description

Technical Field

[0001] The present invention relates to relatively rotating sliding parts, for example, sliding parts used in shaft sealing devices for sealing rotating shafts of rotating machinery in automobiles, general industrial machinery or other sealing fields, or sliding parts used in bearings of machinery in automobiles, general industrial machinery or other bearing fields. Background Art

[0002] As a shaft sealing device for preventing leakage of a sealed fluid, for example, a mechanical seal has a pair of annular sliding members that rotate relative to each other and slide on sliding surfaces. In recent years, in such a mechanical seal, it is desired to reduce energy lost due to sliding for environmental measures and the like.

[0003] For example, in the mechanical seal shown in Patent Document 1, the fluid introduction groove, Rayleigh step and dynamic pressure generating groove are provided on the sliding surface of the rotating side seal ring. The fluid introduction groove is a deep groove connected to the liquid space on the outer diameter side and extending in the radial direction. The Rayleigh step is a shallow groove connected to the fluid introduction groove and extending in the circumferential direction toward the downstream side in the rotation direction. The dynamic pressure generating groove is a spiral groove connected to the gas space on the inner diameter side and extending toward the outer diameter side while being inclined toward the downstream side in the rotation direction.

[0004] In this mechanical seal, when the rotating side seal ring rotates at a low speed, liquid is introduced from the fluid introduction groove to the sliding surfaces, and the sliding surfaces are lubricated by liquid, thereby improving the sliding performance. In addition, when the rotating side seal ring rotates at a high speed such as during steady operation, gas is introduced from the inner diameter end of the dynamic pressure generating groove to generate dynamic pressure near the closed end, thereby slightly separating the sliding surfaces, and gas lubrication is performed between the sliding surfaces, thereby improving the sliding performance.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: International Publication No. 2016 / 167262 (page 13, Figure 7 ) Summary of the invention

[0008] Problems to be solved by the invention

[0009] In a mechanical seal such as that disclosed in Patent Document 1, the pressure in the gas space may change and become higher than the pressure in the liquid space. In such a case, when the rotating seal ring rotates at a low speed, more gas flows from the gas space into the sliding surfaces, and the liquid introduced into the sliding surfaces is pushed back to the liquid space by the gas, which may cause poor lubrication between the sliding surfaces.

[0010] The present invention has been made in view of such a problem, and an object of the present invention is to provide a sliding component capable of preventing poor lubrication between sliding surfaces when the relative rotation is at a low speed.

[0011] Means for solving problems

[0012] In order to solve the above-mentioned problems, in the sliding component of the present invention, a pair of sliding rings rotate relative to each other and divide the first fluid space and the second fluid space, wherein the sliding surfaces of the pair of sliding rings have: a specific dynamic pressure generating groove, which is arranged on the first fluid space side and generates dynamic pressure using the first fluid; a dynamic pressure generating groove, which is arranged at a position closer to the second fluid space side than the specific dynamic pressure generating groove and generates dynamic pressure using the second fluid; a connecting groove, which is connected to the first fluid space; a circumferential groove, which is arranged at a position closer to the second fluid space side than the specific dynamic pressure generating groove and extends circumferentially from the connecting groove; and a first fluid inlet groove, which is arranged at a position closer to the second fluid space side than the circumferential groove and introduces the first fluid.

[0013] Thus, when the relative rotation is at a low speed, the amount of the first fluid provided between the sliding surfaces can be ensured within a large range in the circumferential direction of the circumferential groove, and the first fluid provided from the first fluid introduction groove to the sliding surfaces can be used to suppress the second fluid from moving toward the first fluid space side. Thus, poor lubrication between the sliding surfaces when the relative rotation is at a low speed can be prevented.

[0014] The circumferential groove may be in communication with the first fluid introduction groove.

[0015] Thus, the first fluid can be introduced from the circumferential groove into the first fluid introduction groove.

[0016] The communication groove may extend in the radial direction from the first fluid space toward the circumferential groove.

[0017] This can suppress an excessive amount of the first fluid from being introduced into the communicating groove and the circumferential groove from the first fluid space when the pair of slide rings rotate relative to each other.

[0018] The communication groove may extend from the first fluid space toward the circumferential groove while being inclined in the rotation direction.

[0019] Thus, when the pair of slide rings rotate relative to each other, the first fluid can be smoothly introduced from the first fluid space into the communicating groove and the circumferential groove.

[0020] An annular groove may be formed between the first fluid introducing groove and the dynamic pressure generating groove.

[0021] Thus, the first fluid and the second fluid move along the annular groove, so that the interface between the first fluid and the second fluid can be stabilized.

[0022] Alternatively, the circumferential groove may be annular.

[0023] Thus, the amount of the first fluid supplied from the circumferential groove to between the sliding surfaces can be ensured, and the second fluid can be prevented from moving to the first fluid space side with respect to the circumferential groove.

[0024] The first fluid introduction groove may be a spiral groove.

[0025] Thus, dynamic pressure can be generated at the closed end of the first fluid introduction groove. Furthermore, the first fluid introduction groove can be provided close to each other in the circumferential direction, so the degree of freedom in design is high.

[0026] The dynamic pressure generating groove may be a spiral groove, and a closed end portion of the dynamic pressure generating groove may face a closed end portion of the first fluid introducing groove.

[0027] Thus, the second fluid can be effectively suppressed from moving toward the first fluid space side by the dynamic pressure generated at the closed end portion of the first fluid introduction groove.

[0028] The first fluid may be liquid, and the second fluid may be gas.

[0029] Thus, liquid lubrication can be performed when the relative rotation speed is low, and gas lubrication can be performed when the relative rotation speed is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a longitudinal sectional view showing an example of a mechanical seal according to the first embodiment of the present invention.

[0031] Figure 2 This is a diagram showing the sliding surface of the stationary seal ring of Example 1 as viewed from the axial direction.

[0032] Figure 3 This is an enlarged view of the sliding surface of the stationary seal ring of Example 1 as viewed from the axial direction. It is also a diagram schematically illustrating the operation when the relative rotation is at a low speed.

[0033] Figure 4 This is an enlarged view of the sliding surface of the stationary seal ring according to Example 2 of the present invention as viewed from the axial direction.

[0034] Figure 5 This is a diagram showing the sliding surface of a stationary seal ring according to Example 3 of the present invention as viewed from the axial direction.

[0035] Figure 6 This is an enlarged view of the sliding surface of the stationary seal ring according to Example 4 of the present invention as viewed from the axial direction.

[0036] Figure 7 This is an enlarged view of the sliding surface of the stationary seal ring according to Example 5 of the present invention as viewed from the axial direction.

[0037] Figure 8 This is an enlarged view of the sliding surface of the stationary seal ring according to Example 6 of the present invention as viewed from the axial direction.

[0038] Fig. 9 This is an enlarged view of the sliding surface of the stationary seal ring according to Example 7 of the present invention as viewed from the axial direction. DETAILED DESCRIPTION

[0039] Hereinafter, modes for implementing the sliding member of the present invention will be described based on examples.

[0040] Example 1

[0041] Reference Figures 1 to 3 The sliding component of Example 1 is described. In this example, liquid F as a sealed fluid exists in the outer space S1 as the first fluid space of the mechanical seal, and gas A exists in the inner space S2 as the second fluid space. That is, in this example, the first fluid is liquid F, and the second fluid is gas A. In addition, for the sake of convenience of description, in the drawings, dots are sometimes indicated for grooves and the like formed on the sliding surface.

[0042] Figure 1 The mechanical seal shown is an inside type mechanical seal that seals the liquid F in the outer space S1 that is trying to leak from the outer diameter side to the inner diameter side of the sliding surface, and the inner space S2 communicates with the gas A.

[0043] The mechanical seal mainly includes a stationary seal ring 10 as one sliding ring and a rotating seal ring 20 as the other sliding ring. The rotating seal ring 20 is annular and is mounted on the rotating shaft 1 using a sleeve 2 so as to be rotatable together with the rotating shaft 1 .

[0044] The stationary seal ring 10 is annular and is arranged in a sealing cover 5 in a non-rotating state and in an axially movable state, and the sealing cover 5 is fixed to the housing 4 of the mounted device. The stationary seal ring 10 is urged in the axial direction by the elastic member 7, whereby the sliding surface 11 of the stationary seal ring 10 and the sliding surface 21 of the rotating seal ring 20 slide closely against each other. In addition, the sliding surface 21 of the rotating seal ring 20 is a flat surface, and no recessed portion such as a groove is provided on the flat surface.

[0045] The stationary seal ring 10 and the rotating seal ring 20 are typically formed by a combination of SiC (hard material) and SiC (hard material) or a combination of SiC (hard material) and carbon (soft material), but are not limited thereto. Any sliding material that can be used as a sliding material for a mechanical seal can be used. In addition, as SiC, there are materials composed of two or more phases with different components and compositions, represented by sintered bodies with boron, aluminum, carbon, etc. as sintering aids, such as SiC with dispersed graphite particles, reaction sintered SiC composed of SiC and Si, SiC-TiC, SiC-TiN, etc. As carbon, resin molded carbon, sintered carbon, etc. represented by carbon mixed with carbonaceous and graphite 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.

[0046] like Figure 2 and Figure 3 As shown, the rotating seal ring 20 slides relative to the stationary seal ring 10 in a clockwise direction as indicated by the solid arrow.

[0047] The sliding surface 11 of the stationary sealing ring 10 is provided with a plurality of deep grooves 13 (4 in the present embodiment), a plurality of liquid inlet grooves 14 (60 in the present embodiment) serving as first fluid inlet grooves, a plurality of dynamic pressure generating grooves 15 (60 in the present embodiment) and Rayleigh steps 16 (4 in the present embodiment) serving as specific dynamic pressure generating grooves.

[0048] The portion of the sliding surface 11 other than the deep groove 13, the liquid introduction groove 14, and the dynamic pressure generating groove 15 is a flat land portion 12 arranged on the same plane. The flat surface of the land portion 12 functions as a sliding surface that substantially slides with the sliding surface 21 of the rotary seal ring 20.

[0049] The deep groove 13 has a communicating groove portion 131 as a communicating groove and a circumferential groove portion 132 as a circumferential groove, and is substantially T-shaped when viewed in the axial direction. The communicating groove portion 131 communicates with the outer space S1 and extends from the outer edge of the sliding surface 11 in the inner diameter direction.

[0050] The circumferential groove portion 132 extends from the inner diameter end of the communication groove portion 131 to both sides in the circumferential direction concentrically with the sliding surface 11. The communication groove portion 131 and the circumferential groove portion 132 have the same depth.

[0051] The circumferential length L1 of each circumferential groove portion 132 is greater than the circumferential length L2 of the communication groove portion 131 ( L1 > L2 ).

[0052] The liquid introduction groove 14 is provided on the inner diameter side of the circumferential groove portion 132, separated from the land portion 12a, and is not connected to the circumferential groove portion 132. The liquid introduction groove 14 extends in an arc shape while being inclined with a counterclockwise component from the outer diameter side to the inner diameter side. That is, the liquid introduction groove 14 is a spiral groove.

[0053] The liquid introduction groove 14 is formed to have a constant depth in the circumferential direction. The depth of the liquid introduction groove 14 is shallower than the depth of the deep groove 13. In addition, the liquid introduction groove 14 only needs to have the function of introducing liquid to the inner diameter side, and is not limited to extending in an arc shape while being inclined, and can also extend in a straight line. In addition, the liquid introduction groove 14 of this embodiment introduces liquid to the inner diameter side and generates a positive pressure at the closed end 14A.

[0054] The dynamic pressure generating groove 15 is connected to the inner space S2. The dynamic pressure generating groove 15 extends in an arc shape while being inclined counterclockwise from the outer diameter side to the inner diameter side. That is, the dynamic pressure generating groove 15 is a spiral groove. In addition, the dynamic pressure generating groove 15 may not be connected to the inner space S2.

[0055] The dynamic pressure generating groove 15 extends in an arc shape in the circumferential direction while being inclined with a counterclockwise component from the inner diameter side to the outer diameter side, and is formed to have a constant depth. The depth of the dynamic pressure generating groove 15 is shallower than the depth of the deep groove 13. In addition, the dynamic pressure generating groove 15 is not limited to extending in an arc shape while being inclined, and can also extend in a straight line as long as it has the function of guiding gas to the outer diameter side and generating positive pressure at the closed end 15A.

[0056] The closed end portion 14A on the inner diameter side of the liquid introduction groove 14 and the closed end portion 15A on the outer diameter side of the dynamic pressure generating groove 15 are separated in the radial direction by the land portion 12 c and face each other.

[0057] The Rayleigh step 16 extends counterclockwise from the connecting groove 131 in a concentric circle with the sliding surface 11 and is arranged on the outer diameter side of the annular circumferential groove 132. The Rayleigh step 16 is shallower than the deep groove 13 and has a constant depth in the circumferential direction. In addition, the Rayleigh step 16 may not be connected to the connecting groove 131.

[0058] Next, use Figure 3 The operation of the stationary seal ring 10 and the rotating seal ring 20 when they rotate relative to each other will be described. Figure 3 In FIG. 1 , the flow of liquid F is illustrated as white arrows, and the flow of gas A is illustrated as black arrows.

[0059] First, when the rotary seal ring 20 is stopped without rotating, the liquid F flows into the deep groove 13, the liquid introduction groove 14, and the Rayleigh step 16 provided at the outer space S1 side relative to the land portion 12c. Furthermore, the gas A flows into the dynamic pressure generating groove 15 provided at the inner space S2 side relative to the land portion 12c.

[0060] When not rotating, the stationary seal ring 10 is urged toward the rotating seal ring 20 by the elastic member 7 , so that the sliding surfaces 11 , 21 are in contact with each other, and the amount of liquid F between the sliding surfaces 11 , 21 leaking into the inner space S2 is almost zero.

[0061] like Figure 3 As shown, when the rotating sealing ring 20 starts to rotate at a low speed relative to the stationary sealing ring 10, the liquid F in the deep groove 13, the liquid inlet groove 14, and the Rayleigh step 16, mainly the surface layer of the liquid F, moves in the rotation direction of the rotating sealing ring 20 due to shear with the sliding surface 21.

[0062] Thus, the liquid F in the circumferential groove portion 132 is discharged from the end portion 132A on the upstream side of the relative rotation as indicated by the arrow D2. Figure 2 ) moves toward end 132B on the downstream side of relative rotation.

[0063] The liquid F moving toward the end 132B of the circumferential groove 132 flows out from the end 132B and its vicinity to between the sliding surfaces 11 and 21 as indicated by arrow D3. The deep groove 13 has a depth that does not generate a positive pressure at the end 132B and its vicinity.

[0064] Then, as indicated by arrow D1 , the liquid F in the outer space S1 is introduced into the circumferential groove portion 132 and the Rayleigh step 16 through the communication groove portion 131 .

[0065] Then, as indicated by arrow D8, liquid F in Rayleigh step 16 moves toward closed end 16A of Rayleigh step 16. As indicated by arrow D9, liquid F moving toward closed end 16A of Rayleigh step 16 generates positive pressure at closed end 16A and its vicinity.

[0066] The liquid F in the liquid introduction groove 14 moves from the outer diameter side closed end 14B toward the inner diameter side closed end 14A as shown by arrow D4. The liquid F between the sliding surfaces 11 and 21 is introduced into the liquid introduction groove 14 from the periphery of the closed end 14B.

[0067] The liquid F moving toward the closed end portion 14A of the liquid introduction groove 14 flows out from the closed end portion 14A and the vicinity thereof to between the sliding surfaces 11 and 21 as indicated by arrow D5 .

[0068] Then, the pressure of the liquid F in the liquid introduction groove 14 increases at the closed end portion 14A and its vicinity. That is, a positive pressure is generated at the closed end portion 14A of the liquid introduction groove 14 and its vicinity.

[0069] The sliding surfaces 11 and 21 are slightly separated by the positive pressure generated at the closed end 14A and its vicinity of the liquid inlet groove 14 and the positive pressure generated at the closed end 16A and its vicinity of the Rayleigh step 16, so that the liquid F flows from the outer space S1 into between the sliding surfaces 11 and 12 as shown by the arrow D10, and the gas A flows from the inner space S2 into between the sliding surfaces 11 and 21 as shown by the arrow D11.

[0070] Meanwhile, the gas A in the dynamic pressure generating groove 15 moves from the inner diameter side closed end 15B toward the inner diameter side closed end 15A as indicated by arrow D6. In addition, the gas A between the sliding surfaces 11 and 21 is introduced into the dynamic pressure generating groove 15 from the periphery of the closed end 15B.

[0071] The gas A moving toward the closed end portion 15A of the dynamic pressure generating groove 15 flows out from the closed end portion 15A and the vicinity thereof to between the sliding surfaces 11 and 21 as indicated by arrow D7 .

[0072] When the relative rotation of the rotary seal ring 20 and the stationary seal ring 10 is low speed, the gas A is not dense enough in the dynamic pressure generating groove 15, and a high positive pressure is not generated, and almost no force to separate the sliding surfaces 11 and 21 acts.

[0073] The gas A flowing out from the closed end portion 15A and its vicinity to between the sliding surfaces 11 and 21 is induced to move radially outward, but is pushed back radially inward by the positive pressure generated at the closed end portion 14A and its vicinity of the liquid introduction groove 14 .

[0074] Furthermore, although not shown, when the relative rotation speed of the rotary seal ring 20 increases, a large amount of gas A moves from the closed end 15B of the dynamic pressure generating groove 15 toward the closed end 15A, and the pressure at the closed end 15A and its vicinity increases. That is, a positive pressure is generated at the closed end 15A of the dynamic pressure generating groove 15 and its vicinity.

[0075] At this time, the positive pressure generated at and near the closed end 15A of the dynamic pressure generating groove 15 becomes greater than the positive pressure generated at and near the closed end 14A of the liquid introducing groove 14, and the sliding surfaces 11 and 21 are further separated than when the relative rotation is at a low speed.

[0076] When the mechanical seal of this embodiment rotates at high speed, the sliding surfaces 11 and 21 are separated to such an extent that the liquid F in the deep groove 13 and the liquid introduction groove 14 hardly acts on the sliding surface 21. Therefore, gas lubrication by the gas A is finally performed between the sliding surfaces 11 and 21.

[0077] As described above, when the relative rotation of the stationary seal ring 10 and the rotating seal ring 20 is low speed, the amount of the liquid F supplied to the space between the sliding surfaces 11 and 21 can be ensured over a wide range in the circumferential direction of the circumferential groove portion 132 of the deep groove 13. Furthermore, the gas A supplied to the space between the sliding surfaces 11 and 21 from the inner space S2 or the closed end portion 15A of the dynamic pressure generating groove 15 is pushed back in the inner diameter direction by the liquid F supplied to the space between the sliding surfaces 11 and 21 from the liquid introduction groove 14.

[0078] For example, normally, the pressure of the liquid F in the outer space S1 is higher than the pressure of the gas A in the inner space S2, but there is a case where the pressure of the gas A is higher than the pressure of the liquid F. Even in such a case, since the liquid introduction groove 14 is provided separately at a position closer to the outer diameter side than the closed end 15A of the dynamic pressure generating groove 15, and the liquid introduction groove 14 introduces the liquid F from the outer diameter side, it is possible to suppress the gas A from pushing the liquid F out from between the sliding surfaces 11 and 21. Thus, poor lubrication between the sliding surfaces 11 and 21 when the relative rotation is at a low speed can be prevented.

[0079] Furthermore, the communication groove 131 extends radially from the outer space S1 toward the circumferential groove 132. This can prevent excessive introduction of the liquid F from the outer space S1 into the deep groove 13 when the relative rotation of the stationary seal ring 10 and the rotating seal ring 20 is high speed, thereby preventing the gas lubrication from being hindered.

[0080] Furthermore, since the liquid introduction groove 14 is a spiral groove, dynamic pressure can be generated at the closed end 14A of the liquid introduction groove 14. Therefore, even if the gas A is higher in pressure than the liquid F, the gas A can be effectively pushed back to the inner diameter side.

[0081] Furthermore, since the liquid introduction grooves 14 can be provided close to each other in the circumferential direction, the degree of freedom in design is high.

[0082] The dynamic pressure generating groove 15 is a spiral groove, and the closed end 15A of the dynamic pressure generating groove 15 faces the closed end 14A of the liquid introduction groove 14. Thus, the positive pressure generated at the closed end 14A of the liquid introduction groove 14 can effectively suppress the gas A from moving toward the outer space S1.

[0083] Furthermore, liquid lubrication can be performed using the liquid F when the relative rotation speed is low, and gas lubrication can be performed using the gas A when the relative rotation speed is high.

[0084] In addition, in this embodiment, the deep groove 13 is exemplified as being substantially T-shaped when viewed in the axial direction due to the connecting groove portion 131 and the circumferential groove portion 132, but it may also be formed as an L-shaped when viewed in the axial direction, in which the circumferential groove extends from the inner diameter end of the connecting groove to one side in the circumferential direction. Furthermore, the connecting groove portion may extend to a position closer to the inner diameter side than the circumferential groove portion.

[0085] Furthermore, the circumferential groove portion 132 is not limited to extending in an arc shape, but may also extend in a linear shape.

[0086] Furthermore, in the present embodiment, the liquid inlet groove 14 and the dynamic pressure generating groove 15 are illustrated as spiral grooves inclined with radial and circumferential components, but are not limited to this, and may be indentations having a rectangular or circular shape when viewed in the axial direction, or may be Rayleigh steps extending in the circumferential direction, etc.

[0087] Furthermore, the liquid introduction groove 14 may be a groove deep enough not to generate a positive pressure.

[0088] Furthermore, in the present embodiment, the closed end portion 14A of the liquid inlet groove 14 and the closed end portion 15A of the dynamic pressure generating groove 15 are separated in the radial direction and arranged opposite to each other in a radial line. However, it is not necessary that the closed end portions of the liquid inlet groove and the dynamic pressure generating groove are not on the radial line with each other as long as they are separated in the radial direction.

[0089] Example 2

[0090] Next, refer to Figure 4 The sliding member of Example 2 will be described. In addition, the overlapping description of the structure which is the same as that of the above-mentioned Example 1 is omitted.

[0091] like Figure 4 As shown, in the stationary seal ring 200 of the second embodiment, the outer diameter end of the liquid introduction groove 24 is connected to the circumferential groove portion 232 of the deep groove 23. As a result, a large amount of liquid F can be introduced from the circumferential groove portion 232 of the deep groove 23 to the liquid introduction groove 24, so that the liquid F can be reliably supplied between the sliding surfaces when the relative rotation is low speed, and liquid lubrication can be performed. In addition, even if the gas A is higher pressure than the liquid F, the gas A can be reliably pushed back to the inner diameter side.

[0092] The inner diameter end of the dynamic pressure generating groove 25 communicates with the inner space S2. Thus, gas A can be supplied from the inner space S2 to the dynamic pressure generating groove 25, so that positive pressure can be reliably generated during high-speed relative rotation to separate the sliding surfaces and enable gas lubrication.

[0093] Example 3

[0094] Next, refer to Figure 5 The sliding member of Example 3 will be described. In addition, the overlapping description of the structure which is the same as that of the above-mentioned Example 2 is omitted.

[0095] like Figure 5 As shown, in the stationary seal ring 300 of the third embodiment, the circumferential groove portion 332 of the deep groove 33 is annular. The communication groove portion 331 is communicated with the circumferential groove portion 332 .

[0096] As described above, since the circumferential groove portion 332 is annular, the liquid F can be supplied between the sliding surfaces over the entire circumference of the sliding surface 310 when the relative rotation is low speed, and the supply amount of the liquid F between the sliding surfaces can be ensured.

[0097] Furthermore, even if the gas A moves to the outer diameter side over the liquid introduction groove 34 when the relative rotation is low speed, the gas A is recovered to the circumferential groove portion 332, so that the state in which the liquid F exists at a position closer to the outer diameter side than the circumferential groove portion 332 between the sliding surfaces can be maintained.

[0098] In addition, in the third embodiment, the annular circumferential groove 332 is shown to be connected to four connecting grooves 331, but the connecting groove connected to the annular circumferential groove can be freely changed. For example, as long as the annular circumferential groove is connected to more than one connecting groove, it will be fine.

[0099] Example 4

[0100] Next, refer to Figure 6 The sliding member of the fourth embodiment will be described. In addition, the overlapping description of the structure which is the same as that of the third embodiment will be omitted.

[0101] like Figure 6 As shown, the stationary seal ring 400 of the present embodiment 4 is formed with an annular groove 47 between the liquid introduction groove 44 and the dynamic pressure generating groove 45. Thus, the liquid F introduced between the sliding surfaces from the liquid introduction groove 44 and the gas A introduced between the sliding surfaces from the dynamic pressure generating groove 45 move along the annular groove 47, so that the interface between the liquid F and the gas A can be stabilized.

[0102] The groove provided between the liquid introduction groove 44 and the dynamic pressure generating groove 45 is not limited to the annular groove 47, and may be a substantially C-shaped or arc-shaped groove. In addition, the groove may be provided as a plurality of concentric grooves.

[0103] Example 5

[0104] Next, refer to Figure 7 The sliding member of Example 5 will be described. In addition, the overlapping description of the structure which is the same as that of the above-mentioned Example 4 is omitted.

[0105] like Figure 7 As shown, in the stationary seal ring 500 of the fifth embodiment, the circumferential length L10 of the circumferential groove portion 532 of the deep groove 53 is smaller than the circumferential length L20 of the connecting groove portion 531 (L10<L20). In other words, the area of ​​the deep groove 53 is ensured to be large. Thus, the amount of liquid F supplied from the deep groove 53 to the sliding surfaces or the liquid introduction groove 54 when the relative rotation is at a low speed can be ensured.

[0106] Example 6

[0107] Next, refer to Figure 8 The sliding member of Example 6 will be described. In addition, the overlapping description of the structure which is the same as that of the above-mentioned Example 5 is omitted.

[0108] like Figure 8 As shown, in the stationary seal ring 600 of the fifth embodiment, the communication groove portion 631 of the deep groove 63 extends from the outer space S1 in a counterclockwise direction from the inner diameter direction. Thus, liquid can be smoothly introduced from the outer space S1 to the circumferential groove portion 632 when the relative rotation speed is low.

[0109] Furthermore, the stationary seal ring 600 has a spiral groove 640 as a specific dynamic pressure generating groove. The spiral groove 640 extends substantially parallel to the connecting groove portion 631. Thus, the liquid F in the outer space S1 can be introduced to the inner diameter side by the spiral groove 640, so that more liquid F can be ensured between the sliding surfaces, and the sliding property can be improved.

[0110] Example 7

[0111] Next, refer to Fig. 9 The sliding member of Example 7 will be described. In addition, the overlapping description of the structure which is the same as that of the above-mentioned Example 2 is omitted.

[0112] like Fig. 9 As shown, in the mechanical seal of the present embodiment 7, liquid F exists in the inner space S2 and gas A exists in the outer space S1. The communication groove portion 731 of the deep groove 73 of the stationary seal ring 700 communicates with the inner space S2.

[0113] The liquid introduction groove 74 extends in an arc shape toward the outer diameter side from the circumferential groove portion 732 of the deep groove 73 while being inclined with a counterclockwise component.

[0114] The dynamic pressure generating groove 75 extends in an arc shape from the outer diameter side toward the inner diameter side while being inclined with a counterclockwise component. The outer diameter end of the dynamic pressure generating groove 75 communicates with the outer space S1.

[0115] The Rayleigh step 76 extends counterclockwise from the communication groove portion 731 in a concentric circle with the sliding surface.

[0116] As mentioned above, although the embodiment of the present invention is described with reference to the drawings, the specific structure is not limited to these embodiments, and the change and addition within the range which does not deviate from the meaning of the present invention are also included in the present invention.

[0117] For example, in the above-mentioned embodiments 1 to 7, the mechanical seal is used as an example of the sliding component, but the sliding component may be a shaft seal component other than the mechanical seal. Furthermore, the sliding component may be a bearing component other than the shaft seal component.

[0118] Furthermore, in the aforementioned embodiments 1 to 7, the example of providing the deep groove, the liquid introduction groove, and the dynamic pressure generating groove on the stationary sealing ring is described, but each groove may also be provided on the rotating sealing ring. In other words, the sliding ring of one side of the present invention may be either a stationary sealing ring or a rotating sealing ring. Furthermore, it may also be provided on both the stationary sealing ring and the rotating sealing ring. Furthermore, as long as the sliding surfaces of a pair of sliding rings have these grooves, for example, it may also be provided that the sliding surface of one sliding ring has a deep groove and a liquid introduction groove, and the sliding surface of the other sliding ring has a dynamic pressure generating groove.

[0119] Furthermore, in the above-mentioned Examples 1 to 7, a method in which liquid F exists in one of the outer space and the inner space and gas A exists in the other is illustrated, but liquid F may exist in both spaces, and gas A may exist in both spaces.

[0120] Furthermore, in the aforementioned embodiments 1 to 7, the gas A may be in the form of a mist mixed with liquid and gas.

[0121] Furthermore, in the aforementioned embodiments 1 to 7, the bottom surfaces of the deep grooves, liquid inlet grooves, and dynamic pressure generating grooves are illustrated as extending parallel to the flat surface of the land portion, but this is not limited to this. For example, the bottom surface of each groove may be inclined in a manner that becomes shallower toward the downstream side of the relative rotation.

[0122] In the above-mentioned embodiments 4 to 6, the specific dynamic pressure generating groove is connected to the liquid space, but it is not necessarily connected to the liquid space. Furthermore, the specific dynamic pressure generating groove is not limited to the Rayleigh step or the spiral groove, and can be freely changed.

[0123] Description of symbols

[0124] 1: rotating shaft; 2: sleeve; 4: housing; 10: stationary seal ring (sliding ring on one side); 11: sliding surface; 12c: land portion; 13: deep groove; 14: liquid introduction groove; 14A: closed end; 15: dynamic pressure generating groove; 15A: closed end; 16: Rayleigh step (specific dynamic pressure generating groove); 20: rotating seal ring; 21: sliding surface; 23: deep groove; 24: liquid introduction groove; 25: dynamic pressure generating groove; 33: deep groove; 34: liquid introduction groove; 43: deep groove; 44: liquid inlet groove; 53: deep groove; 63: deep groove; 73: deep groove; 74: liquid inlet groove; 75: dynamic pressure generating groove; 131: connecting groove portion (connecting groove); 132: circumferential groove portion (circumferential groove); 200~700: stationary sealing ring; 640: spiral groove (specific dynamic pressure generating groove); A: gas (second fluid); F: liquid (first fluid); S1: outer space (first fluid space); S2: inner space (second fluid space).

Claims

1. A sliding component, wherein a pair of sliding rings of the sliding component rotate relative to each other and divide a first fluid space and a second fluid space, wherein: The sliding surfaces of a pair of the sliding rings have: a specific dynamic pressure generating groove, which is provided on the first fluid space side and generates dynamic pressure using the first fluid; a dynamic pressure generating groove disposed at a position closer to the second fluid space than the specific dynamic pressure generating groove, and generating dynamic pressure using the second fluid; a communication groove, which is communicated with the first fluid space; a circumferential groove provided at a position closer to the second fluid space than the specific dynamic pressure generating groove and extending from the communicating groove in the circumferential direction; as well as The first fluid introduction groove is provided at a position closer to the second fluid space than the circumferential groove, and introduces the first fluid.

2. The sliding component according to claim 1, wherein: The circumferential groove communicates with the first fluid introduction groove.

3. The sliding component according to claim 1, wherein: The communication groove extends radially from the first fluid space toward the circumferential groove.

4. The sliding component according to claim 1, wherein: The communication groove extends from the first fluid space toward the circumferential groove while being inclined in the rotation direction.

5. The sliding component according to claim 1, wherein: An annular groove is formed between the first fluid introduction groove and the dynamic pressure generating groove.

6. The sliding component according to claim 1, wherein: The circumferential groove is annular.

7. The sliding component according to claim 1, wherein: The first fluid introduction groove is a spiral groove.

8. The sliding component according to claim 7, wherein: The dynamic pressure generating groove is a spiral groove, and a closed end portion of the dynamic pressure generating groove faces a closed end portion of the first fluid introducing groove.

9. The sliding component according to any one of claims 1 to 8, wherein: The first fluid is liquid, and the second fluid is gas.

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