Sliding parts

Abstract

A sliding component is provided, which can suppress the accumulation of dirt in a conducting groove. A sliding component (10) is annular, arranged at a relatively rotating part of a rotary machine, and slides relatively with other sliding components (20), wherein a sliding surface (11) of the sliding component (10) is provided with: a conducting groove (15) which is connected to an external space (S1); and a dynamic pressure generating groove (16) which is connected to the conducting groove (15), extends in the circumferential direction, and has a closed terminal portion (16B), and the bottom (15a) of the conducting groove (15) has an inclined surface (15a) inclined in the radial direction at least in a part.

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 parts 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, the mechanical seal shown in Patent Document 1 is provided with a dynamic pressure generating mechanism on the sliding surface of a sliding part. The dynamic pressure generating mechanism comprises: a conduction groove extending in the radial direction and communicating with the external space where the sealed fluid exists; and a dynamic pressure generating groove extending in the circumferential direction from the conduction groove and having a closed terminal, and the conduction groove is formed to be deeper than the dynamic pressure generating groove. Thus, when the sliding parts rotate relatively, the sealed fluid is introduced from the external space into the dynamic pressure generating groove via the conduction groove, and the sealed fluid moves toward the terminal of the dynamic pressure generating groove, generating positive pressure at the terminal of the dynamic pressure generating groove, separating the sliding surfaces from each other, and the sealed fluid is interposed between the sliding surfaces, thereby improving lubricity.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: International Publication No. 2012 / 046749 (page 17, Figure 1 ) Summary of the invention

[0007] Problems to be solved by the invention

[0008] In a sliding component such as that of Patent Document 1, since the conduction groove is filled with fluid, when the sliding component rotates relatively, although the fluid can be reliably supplied from the conduction groove to the dynamic pressure generating groove, the conduction groove is deeper than the dynamic pressure generating groove and is filled with a large amount of fluid, there is a possibility that dirt will accumulate in the conduction groove and the dirt will be sandwiched between the sliding surfaces and cause abrasive wear.

[0009] The present invention has been made in view of such a problem, and an object of the present invention is to provide a sliding member capable of suppressing accumulation of dirt in a conduction groove.

[0010] Means for solving problems

[0011] In order to solve the above-mentioned problems, the sliding component of the present invention is annular, arranged in a relatively rotating position of a rotating machine, and slides relative to other sliding components, wherein the sliding surface of the sliding component is provided with: a conducting groove, which is connected to the external space; and a dynamic pressure generating groove, which is connected to the conducting groove, extends in the circumferential direction, and has a closed terminal portion, and the bottom of the conducting groove has an inclined surface inclined in the radial direction at least in a portion.

[0012] Thus, when the sliding parts rotate relatively, the fluid on the upper surface side of the conducting groove is mainly subjected to shear force, and a vortex flow centered in the radial direction is generated in the conducting groove. The vortex flow is affected by the inclined surface and tilts along the inclined surface, and a component flowing in the radial direction is generated in the fluid in the conducting groove. In this way, a flow of the fluid traveling back and forth in the radial direction is induced in the conducting groove, and dirt flowing into the conducting groove is discharged to the outside of the conducting groove, which can prevent the dirt from accumulating in the conducting groove.

[0013] The inclined surface may be formed over the entire radial area of ​​the bottom of the conducting groove.

[0014] Thus, the fluid can flow smoothly in the radial direction in the conduction groove.

[0015] The radial end portion of the conduction groove on the external space side may be wider in the circumferential direction than an end portion of the conduction groove on the radially opposite side to the external space.

[0016] As a result, the peripheral surface of the radial external space side of the sliding component and the side wall surface of the conduction groove are easy to form an angle along the circumferential direction, in other words, an obtuse angle. Due to its viscosity, the fluid is easy to move along the peripheral surface of the radial external space side of the sliding component and the side wall surface of the conduction groove, so it is easy to take the fluid in the external space into the conduction groove, and easy to discharge the fluid in the conduction groove to the external space.

[0017] The dynamic pressure generating grooves may be entirely connected at a portion shallower than the inclined surface.

[0018] Thus, a larger communicating area between the dynamic pressure generating groove and the conduction groove can be ensured, and a step is formed between the conduction groove and the dynamic pressure generating groove, so that dirt in the conduction groove is less likely to enter the dynamic pressure generating groove.

[0019] The inclined surface may be continuous with the sliding surface.

[0020] This makes it easier for the fluid to be discharged between the conducting groove and the sliding surface.

[0021] Alternatively, when viewed from the axial direction, the side wall portion of the conducting groove may be in an arc shape.

[0022] Thus, the fluid in the conduction groove can flow smoothly in the radial direction along the side wall portion.

[0023] The dynamic pressure generating groove may be in communication with the external space.

[0024] Thus, even if waste flows into the dynamic pressure generating groove, the waste can be easily discharged to the external space.

[0025] The dynamic pressure generating groove and the external space may be separated by a land portion.

[0026] Thus, leakage of the fluid in the dynamic pressure generating groove to the external space can be suppressed, and thus positive pressure or negative pressure can be generated as high dynamic pressure in the dynamic pressure generating groove.

[0027] In addition, the external space in the present invention may be an external space existing on the outer diameter side of the sliding member, or may be an internal space existing on the inner diameter side of the sliding member. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a longitudinal sectional view showing an example of a mechanical seal according to the first embodiment of the present invention.

[0029] Figure 2 This is a diagram showing the sliding surface of the stationary seal ring as viewed from the axial direction.

[0030] Figure 3 It is a cross-sectional view along line AA.

[0031] Figure 4 It is a cross-sectional view along line BB.

[0032] Figure 5 It is a schematic diagram showing the flow of fluid in the conduction groove and the dynamic pressure generating groove during relative rotation.

[0033] Figure 6 It is a schematic diagram showing the flow of the fluid in the conduction groove during relative rotation.

[0034] Figure 7 This is an explanatory diagram showing a first modification of the stationary seal ring of the first embodiment.

[0035] Figure 8 This is an explanatory diagram showing a second modification of the stationary seal ring of the first embodiment.

[0036] Fig. 9 This is an explanatory diagram showing a third modification of the stationary seal ring of the first embodiment.

[0037] Fig.10 This is an explanatory diagram showing a fourth modification of the stationary seal ring of the first embodiment.

[0038] Fig.11 This is an explanatory diagram showing a fifth modification of the stationary seal ring of the first embodiment.

[0039] Fig.12 This is an explanatory diagram showing a sixth modification of the stationary seal ring of the first embodiment.

[0040] Fig.13 It is an explanatory diagram showing the dynamic pressure generating groove and the conduction groove according to the second embodiment of the present invention.

[0041] Fig.14 It is an explanatory diagram showing a seventh modification of the stationary seal ring of the first and second embodiments. DETAILED DESCRIPTION

[0042] Hereinafter, modes for implementing the sliding member of the present invention will be described based on examples.

[0043] Example 1

[0044] Reference Figures 1 to 6 The sliding component of Example 1 is described. In this example, the sliding component is a mechanical seal. In the example, the sealed fluid F exists in the inner space S1 as the outer space on the inner diameter side of the mechanical seal, and the atmosphere A exists in the outer space S2 as the outer space on the outer diameter side. In addition, for the convenience of description, dots are sometimes added to grooves and the like formed on the sliding surface in the drawings.

[0045] Figure 1 The mechanical seal for general industrial machinery shown is an outer seal that seals the sealed fluid F that leaks from the inner diameter side of the sliding surface to the outer diameter side. In addition, in this embodiment, the sealed fluid F is a high-pressure liquid and the atmosphere A is a gas with a lower pressure than the sealed fluid F.

[0046] The mechanical seal mainly comprises: a housing 5 fixed to a housing 4 of a mounted device; a circular annular stationary seal ring 10 as a sliding component, which is arranged on the housing 5 in a non-rotating state and axially movable state; a circular annular rotating seal ring 20 as another sliding component, which is arranged on the rotating shaft 1 by means of a sleeve 2 in a state that it can rotate together with the rotating shaft 1; a secondary seal 9 that seals the housing 5 and the stationary seal ring 10 in the radial direction; and a force applying unit 7 that is arranged between the housing 5 and the stationary seal ring 10. In this mechanical seal, the stationary seal ring 10 is axially forced by the force applying unit 7, so that the sliding surface 11 of the stationary seal ring 10 and the sliding surface 21 of the rotating seal ring 20 slide closely against each other. In addition, the sliding surface 21 of the rotating seal ring 20 is a flat surface, and no recessed parts such as grooves are provided on the flat surface.

[0047] 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 to this. Any sliding material can be used as long as it can be used as a sliding material for a mechanical seal. In addition, as SiC, there are materials composed of two or more phases with different components and compositions, represented by sintered bodies using 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.

[0048] like Figure 2 As shown, the rotating seal ring 20 slides relative to the stationary seal ring 10 in the counterclockwise direction as shown by the arrow. On the sliding surface 11 of the stationary seal ring 10, a plurality of (eight in Embodiment 1) dynamic pressure generating mechanisms 14 are evenly arranged along the circumferential direction on the inner diameter side. In addition, the upper part of the portion of the sliding surface 11 other than the dynamic pressure generating mechanism 14 is a land portion 12 constituting a flat end surface. In addition, a positive pressure generating mechanism such as a pit may be formed on the outer diameter side of the sliding surface 11.

[0049] Next, based on Figure 2 to Figure 4 The outline of the dynamic pressure generating mechanism 14 will be described. In addition, in the following, for the convenience of description, the fluid induction groove 15 is shown shallower than it actually is.

[0050] The dynamic pressure generating mechanism 14 includes: a fluid induction groove 15 as a conducting groove, which is connected to the inner space S1; a first dynamic pressure generating groove 16 for generating positive pressure, which extends counterclockwise along the circumferential direction from the fluid induction groove 15; and a second dynamic pressure generating groove 17 for generating negative pressure, which extends clockwise along the circumferential direction from the fluid induction groove 15.

[0051] The fluid induction groove 15 has a bottom surface 15a as a bottom, which is semicircular and convex to the outer diameter side when viewed from the axial direction, and a side wall portion 15b extending vertically along the arc-shaped side edge of the bottom surface 15a toward the flat surface of the land portion 12. In this way, the communication portion 15c (i.e., the radial end portion on the external space side) of the fluid induction groove 15 that communicates with the inner space S1 is formed to be wider in the circumferential direction than the radially outermost portion 15d, which is the top portion on the outer diameter side of the fluid induction groove 15.

[0052] In addition, the bottom surface 15a is an inclined surface 15a composed of a plane that gradually becomes shallower in the radial direction from the inner diameter side to the outer diameter side, and the radially outermost portion 15d of the bottom surface 15a (i.e., the end portion on the radially opposite side to the external space) extends to the flat surface of the land portion 12. That is, a surface that is inclined over the entire radial region of the bottom surface 15a is formed. In addition, the fluid induction groove 15 has a radial maximum width W1 at the radially outermost portion 15d.

[0053] The communicating portion 15c, which is the radially innermost portion of the fluid guiding groove 15, has the deepest depth D1. The depth D1 of the present embodiment is 100 μm. The deepest depth D1 of the fluid guiding groove 15 can be freely changed.

[0054] In addition, the fluid induction groove 15 is connected to the virtual line LN extending in the radial direction (see Figure 5 ) as a reference and present a symmetrical shape in the circumferential direction.

[0055] The first dynamic pressure generating groove 16 has a relatively rotating starting end portion 16A that is connected to the fluid inducing groove 15, and a relatively rotating terminal end portion 16B that is closed. Specifically, the first dynamic pressure generating groove 16 has a bottom surface 16a that is flat and parallel to the flat surface of the land portion 12 in the range from the starting end portion 16A to the terminal end portion 16B, a wall portion 16b that extends vertically from the end edge of the terminal end portion 16B of the bottom surface 16a toward the flat surface of the land portion 12, and a side wall portion 16c that extends vertically from the side edge on the outer diameter side of the bottom surface 16a toward the flat surface of the land portion 12, and the side edge on the inner diameter side of the bottom surface 16a is connected to the inner space S1.

[0056] The radial width W2 of the first dynamic pressure generating groove 16 is constant in the circumferential range thereof, and the width W2 is smaller than the width W1 (W1>W2).

[0057] In addition, the first dynamic pressure generating groove 16 has a constant depth D2 in the range from the starting end portion 16A to the terminal end portion 16B. The depth D2 of the present embodiment is 10 μm. In addition, the depth D2 of the first dynamic pressure generating groove 16 can be freely changed, but preferably, the depth D2 is less than 1 / 10 times the depth D1.

[0058] The relative rotation starting end portion 17A of the second dynamic pressure generating groove 17 is closed, and the relative rotation terminal portion 17B is connected to the fluid inducing groove 15. Specifically, the second dynamic pressure generating groove 17 has a bottom surface 17a which is flat in the range from the starting end portion 17A to the terminal portion 17B and is parallel to the flat surface of the land portion 12, a wall portion 17b extending vertically from the end edge of the terminal portion 17B of the bottom surface 17a toward the flat surface of the land portion 12, and a side wall portion 17c extending vertically from the side edge on the outer diameter side of the bottom surface 17a toward the flat surface of the land portion 12, and the side edge on the inner diameter side of the bottom surface 17a is connected to the inner space S1.

[0059] The radial width W3 of the second dynamic pressure generating groove 17 is constant within its circumferential range, and the width W3 is smaller than the width W1 (W3>W1). In addition, the width W3 is the same as the width W2 (W2=W3). In addition, the width W2 and the width W3 may be different in size.

[0060] In addition, the second dynamic pressure generating groove 17 has a constant depth D3 in the range from the starting end portion 17A to the terminal end portion 17B. The depth D3 of the present embodiment is 10 μm (D1=D2). In addition, the depth D2 of the first dynamic pressure generating groove 16 and the depth D3 of the second dynamic pressure generating groove 17 may also be different in size. In addition, the depth D3 of the second dynamic pressure generating groove 17 can be freely changed, but preferably, the depth D3 is less than 1 / 10 times the depth D1.

[0061] The first dynamic pressure generating grooves 16 and the second dynamic pressure generating grooves 17 are symmetrically shaped in the circumferential direction with reference to an imaginary line LN extending in the radial direction.

[0062] In addition, the first dynamic pressure generating groove 16 and the second dynamic pressure generating groove 17 are connected in a region shallower than the bottom surface 15a of the fluid inducing groove 15. That is, a step is formed by the side wall portion 15b located between the bottom surface 15a of the fluid inducing groove 15 and the first dynamic pressure generating groove 16 and the second dynamic pressure generating groove 17.

[0063] Next, use Figure 5 The flow of the sealed fluid F when the stationary seal ring 10 and the rotating seal ring 20 rotate relative to each other will be briefly described. Figure 5 The flow of the sealed fluid F is schematically shown without specifying the relative rotation speed of the rotating seal ring 20 .

[0064] First, when the general industrial machinery is not in operation and the rotating seal ring 20 does not rotate, the stationary seal ring 10 is forced toward the rotating seal ring 20 by the force applying unit 7, so that the sliding surfaces 11 and 21 are in contact with each other, and the amount of the sealed fluid F in the first dynamic pressure generating groove 16 and the second dynamic pressure generating groove 17 leaking from between the sliding surfaces 11 and 21 to the external space S2 is almost zero.

[0065] like Figure 5 As shown, when the rotating seal ring 20 rotates relative to the stationary seal ring 10 , the sealed fluid F in the fluid inducing groove 15 , the first dynamic pressure generating groove 16 and the second dynamic pressure generating groove 17 moves in the rotation direction of the rotating seal ring 20 due to friction with the sliding surface 21 .

[0066] Specifically, as indicated by arrow L1 , the sealed fluid F in the first dynamic pressure generating groove 16 moves from the starting end portion 16A toward the terminal end portion 16B, and accordingly, as indicated by arrow L3 , the sealed fluid F in the fluid inducing groove 15 flows into the first dynamic pressure generating groove 16 .

[0067] The sealed fluid F in the first dynamic pressure generating groove 16 moving toward the terminal portion 16B has its pressure increased at the wall portion 16b and its vicinity. That is, a positive pressure is generated at the wall portion 16b and its vicinity.

[0068] In addition, since the first dynamic pressure generating groove 16 is connected to the inner space S1, as shown by the arrow L1', a portion of the sealed fluid F in the inner space S1 flows into the first dynamic pressure generating groove 16, and, as shown by the arrow L1", a portion of the sealed fluid F in the first dynamic pressure generating groove 16 flows out of the inner space S1.

[0069] Furthermore, as indicated by arrow L2 , the sealed fluid F in the second dynamic pressure generating groove 17 moves from the starting end portion 17A toward the terminal end portion 17B and flows out into the fluid inducing groove 15 .

[0070] Negative pressure is generated in the second dynamic pressure generating groove 17 where the sealed fluid F moves toward the terminal portion 17B. In the second dynamic pressure generating groove 17, the pressure at the start end portion 17A becomes lower than the pressure at the terminal portion 17B.

[0071] In addition, since the second dynamic pressure generating groove 17 is connected to the inner space S1, as shown by the arrow L2', a portion of the sealed fluid F in the inner space S1 flows into the second dynamic pressure generating groove 17, and at the same time, as shown by the arrow L2", a portion of the sealed fluid F in the second dynamic pressure generating groove 17 flows out of the inner space S1.

[0072] Furthermore, as indicated by arrow L3 , the sealed fluid F in the fluid induction groove 15 , particularly the sealed fluid F at the upper portion of the fluid induction groove 15 , moves in the circumferential direction from the second dynamic pressure generating groove 17 side toward the first dynamic pressure generating groove 16 side.

[0073] Since the fluid induction groove 15 is connected to the inner space S1, a portion of the sealed fluid F in the inner space S1 flows into the fluid induction groove 15 as shown by arrow L4, and a portion of the sealed fluid F in the fluid induction groove 15 flows out of the inner space S1 as shown by arrow L5.

[0074] In addition, when the relative rotation speed of the stationary seal ring 10 and the rotating seal ring 20 becomes greater than a certain value, the positive pressure in the wall portion 16b of the first dynamic pressure generating groove 16 and its vicinity becomes large, and as shown by the arrow L6, the sealed fluid F in the first dynamic pressure generating groove 16 flows out from the terminal portion 16B to between the sliding surfaces 11 and 21. As a result, the sliding surfaces 11 and 21 are separated. The sealed fluid F in the first dynamic pressure generating groove 16 flows out from the corner portion formed by the wall portion 16b and the side wall portion 16c toward the outer diameter direction to between the sliding surfaces 11 and 21.

[0075] On the other hand, in the second dynamic pressure generating groove 17, the negative pressure generated at the starting end 17A becomes larger, which can suck the sealed fluid F between the sliding surfaces 11 and 21 near the starting end 17A into the second dynamic pressure generating groove 17 and return it to the fluid inducing groove 15, thereby preventing the sealed fluid F between the sliding surfaces 11 and 21 from leaking to the external space S2.

[0076] In addition, at the side of the first dynamic pressure generating groove 16 of the side wall portion 15b of the fluid inducing groove 15, the pressure of the sealed fluid F in the fluid inducing groove 15 is increased due to the shear force, generating a positive pressure, thereby causing the sealed fluid F in the fluid inducing groove 15 to slightly flow out between the sliding surfaces 11 and 21 as shown by the arrow L7.

[0077] Next, use Figure 6 The flow of the sealed fluid F in the fluid induction groove 15 will be described.

[0078] like Figure 6 As shown, when the stationary seal ring 10 and the rotating seal ring 20 rotate relative to each other, the sealed fluid F in the fluid induction groove 15, especially the sealed fluid F at the top of the fluid induction groove 15, is subjected to shear force from the sliding surface 21 of the rotating seal ring 20. Since the bottom surface 15a of the fluid induction groove 15 is inclined from the inner diameter side to the outer diameter side, a vortex flow F1 (i.e., a vortex flow F1 having a component flowing in the radial direction and a component swirling in the circumferential direction) is generated in the fluid induction groove 15, with the vortex flow being roughly centered along the radial direction and the inclination direction of the bottom surface 15a. Figure 6 In FIG. 1 , for the sake of convenience of explanation, a plurality of vortex flows are illustrated in the radial direction.

[0079] When the fluid inducing groove 15 is observed radially from the inner space S1 side, the vortex flow F1 swirls in the order of the sliding surface 21 of the rotating seal ring 20, the portion of the side wall portion 15b on the first dynamic pressure generating groove 16 side, the bottom surface 15a, and the portion of the side wall portion 15b on the second dynamic pressure generating groove 17 side.

[0080] In addition, the bottom surface 15a of the fluid induction groove 15 is inclined in the radial direction so as to gradually become shallower toward the outer diameter side, so that the volume of the fluid that can flow varies depending on the radial position of the fluid induction groove 15, thereby generating a speed difference depending on the radial position, and the vortex flow F1 has a component flowing in the radial direction. In addition, since the bottom surface 15a is inclined, the fluid flows smoothly in the radial direction.

[0081] In this way, when the stationary sealing ring 10 and the rotating sealing ring 20 rotate relative to each other, a vortex flow F1 having a component flowing in the radial direction is generated. Therefore, as shown by the arrow L4, a part of the sealed fluid F in the inner space S1 flows into the fluid induction groove 15, and, as shown by the arrow L5, a part of the sealed fluid F in the fluid induction groove 15 flows out of the inner space S1.

[0082] In particular, since the radially outermost portion 15d side of the fluid inducing groove 15 becomes shallower, when the relative rotation speed between the stationary sealing ring 10 and the rotating sealing ring 20 becomes above a certain level, the pressure of the sealed fluid F in the fluid inducing groove 15 is higher on the radially outermost portion 15d side than on the connecting portion 15c side. Therefore, the sealed fluid F in the inner space S1 indicated by the arrow L4 is not easy to flow to the radially outermost portion 15d of the fluid inducing groove 15. For example, most of the sealed fluid F indicated by the arrow L4 will flow to the radially central portion of the fluid inducing groove 15, and then return from there to flow toward the inner space S1 (i.e., the flow indicated by the arrow L5).

[0083] As described above, when the stationary seal ring 10 and the rotating seal ring 20 rotate relative to each other, the sealed fluid F in the fluid induction groove 15 is affected by the inclined bottom surface 15a and generates a vortex flow F1 in a radially inclined manner. Therefore, the sealed fluid F in the fluid induction groove 15 generates a component that flows in the radial direction, so that the dirt that flows into the fluid induction groove 15 can be discharged to the outside of the fluid induction groove 15, and the accumulation of dirt in the fluid induction groove 15 can be suppressed. In addition, since a part of the sealed fluid F in the fluid induction groove 15 has a pressure increase at the part on the side of the first dynamic pressure generating groove 16 of the side wall portion 15b, it flows out between the sliding surfaces 11 and 21, thereby promoting the radial flow of the sealed fluid F in the fluid induction groove 15 (refer to Figure 5 and Figure 6 . Arrow L7).

[0084] Specifically, the dirt that flows into the fluid induction groove 15 is mainly discharged into the inner space S1 along with the flow of the sealed fluid F that flows out from the fluid induction groove 15 into the inner space S1 (see Figure 5 and Figure 6 In addition, part of the dirt is discharged between the sliding surfaces 11 and 21 along with the flow of the sealed fluid F flowing out from the fluid induction groove 15 to between the sliding surfaces 11 and 21 (see Figure 5 and Figure 6 In addition, the amount of dirt discharged between the sliding surfaces 11 and 21 is less than the amount of dirt discharged into the inner space S1.

[0085] Furthermore, since the contaminants accumulated on the bottom surface 15 a of the fluid inducing groove 15 can be swirled by the vortex flow F1 generated in the fluid inducing groove 15 and moved radially together with the sealed fluid F, the contaminants can be easily discharged out of the fluid inducing groove 15 .

[0086] The bottom surface 15a of the fluid induction groove 15 is a flat surface that extends obliquely from the communication portion 15c to the radially outermost portion 15d of the bottom surface 15a. That is, the sealed fluid F in the fluid induction groove 15 flows smoothly in the radial direction. In addition, the flat surface may be formed with a step portion that does not hinder the radial flow or with unavoidable unevenness in manufacturing as long as the sealed fluid F can flow in the radial direction.

[0087] In addition, the connecting portion 15c of the fluid induction groove 15 connected to the inner space S1 is formed to be wider in the circumferential direction than the top side of the outer diameter side of the fluid induction groove 15, so the inner circumferential surface of the stationary sealing ring 10 and the side wall portion 15b of the fluid induction groove 15 form an angle (obtuse angle) along the circumferential direction. Due to its viscosity, the fluid is easy to move along the inner circumferential surface of the stationary sealing ring 10 and the side wall portion 15b of the fluid induction groove 15, so it is easy to take the sealed fluid F in the inner space S1 into the fluid induction groove 15, and it is easy to discharge the sealed fluid F in the fluid induction groove 15 into the inner space S1.

[0088] In addition, the first dynamic pressure generating groove 16 and the second dynamic pressure generating groove 17 are connected in a region shallower than the bottom surface 15a of the fluid inducing groove 15. Thus, the connecting region of the first dynamic pressure generating groove 16 and the second dynamic pressure generating groove 17 and the fluid inducing groove 15 can be ensured to be large, and a step is formed by the side wall portion 15b between the bottom surface 15a of the fluid inducing groove 15 and the first dynamic pressure generating groove 16 and the second dynamic pressure generating groove 17, so that the dirt existing in the fluid inducing groove 15 is not easy to enter the first dynamic pressure generating groove 16 and the second dynamic pressure generating groove 17. In addition, the height of the side wall portion 15b can be ensured, so that the vortex flow F1 is easily formed in the radial range thereof.

[0089] In addition, since the radially outermost portion 15d of the bottom surface 15a of the fluid inducing groove 15 extends to the flat surface of the land portion 12 and is continuous therewith, the fluid can be discharged between the fluid inducing groove 15 and the sliding surfaces 11 and 21, and the radial flow of the sealed fluid F in the fluid inducing groove 15 can be promoted.

[0090] When viewed from the axial direction, the side wall portion 15b of the fluid induction groove 15 is arc-shaped. Thus, the side wall portion 15b has no corners, so the sealed fluid F in the fluid induction groove 15 does not stagnate and can flow smoothly in the radial direction along the side wall portion 15b.

[0091] In addition, the fluid induction groove 15 is connected to the virtual line LN extending in the radial direction (see Figure 5 ) is used as a reference and is symmetrical in the circumferential direction. Therefore, the sealed fluid F in the fluid induction groove 15 flows evenly along the side wall portion 15b.

[0092] In addition, since the first dynamic pressure generating groove 16 and the second dynamic pressure generating groove 17 are connected to the inner space S1, even if dirt flows into the first dynamic pressure generating groove 16 and the second dynamic pressure generating groove 17, it can be discharged to the inner space S1 together with the "arrow L1" and the "arrow L2", which can prevent the dirt from accumulating in the first dynamic pressure generating groove 16 and the second dynamic pressure generating groove 17.

[0093] In addition, in the above-mentioned embodiment, the side wall portion 15b of the fluid induction groove 15 is exemplified as being in an arc shape when viewed from the axial direction, but it is not limited thereto. For example, it may also be as follows: Figure 7 As shown, when viewed from the axial direction, the fluid induction groove 151 is roughly rectangular, and more specifically, is formed into the following shape: the inner space S1 side is an arc, the outer space S2 side is a straight line, and the radial sides are respectively surrounded by straight lines perpendicular to the straight line on the outer space S2 side.

[0094] In addition, you can also Figure 8 As shown, when viewed from the axial direction, the fluid induction groove 152 is formed into a roughly trapezoidal shape with a width widened on the inner space S1 side. Specifically, it is formed into the following shape: the inner space S1 side is an arc, the outer space S2 side is a straight line, and the radial sides are respectively surrounded by straight lines connected to the straight lines on the outer space S2 side at obtuse angles.

[0095] In the above-mentioned embodiment, the fluid induction groove 15 is symmetrically shaped in the circumferential direction with respect to the imaginary line LN extending in the radial direction as a reference. However, for example, the fluid induction groove 15 may be symmetrically shaped in the circumferential direction. Fig. 9 As shown, the fluid induction groove 153 is formed in an elliptical shape that is asymmetrical in the circumferential direction with respect to the imaginary line LN extending in the radial direction. In addition, the fluid induction groove 153 may also be formed in a rectangular shape or other polygonal shape that is asymmetrical in the circumferential direction with respect to the imaginary line LN.

[0096] In the above embodiment, the end portions of the first dynamic pressure generating groove 16 and the second dynamic pressure generating groove 17 on the inner space S1 side are provided at positions separated from the circumferential end portions of the fluid inducing groove 15 in the circumferential direction. However, the above embodiment may be provided in the form of Fig.10As shown, the end portions 161 a and 171 a of the first dynamic pressure generating groove 161 and the second dynamic pressure generating groove 171 on the inner space S1 side are provided at the same circumferential positions as the circumferential ends of the fluid inducing groove 15 .

[0097] In the above embodiment, the first dynamic pressure generating groove 16 and the second dynamic pressure generating groove 17 are extended on both sides of the fluid inducing groove 15 in the circumferential direction. Fig.11 As shown, the first dynamic pressure generating groove 162 (ie, the positive pressure generating groove) is provided to extend only in the circumferential direction with respect to the fluid inducing groove 15 .

[0098] In addition, you can also Fig.12 As shown, the second dynamic pressure generating groove 172 (ie, the negative pressure generating groove) is provided to extend only in the circumferential direction with respect to the fluid inducing groove 15 .

[0099] Example 2

[0100] Next, refer to Fig.13 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 embodiment will be omitted.

[0101] like Fig.13 As shown, the fluid inducing groove 15, the first dynamic pressure generating groove 163 and the second dynamic pressure generating groove 173 are formed on the sliding surface 110 of the stationary seal ring 100. The first dynamic pressure generating groove 163 and the second dynamic pressure generating groove 173 are separated from the inner space S1 by the land portion 120.

[0102] Thus, leakage of the sealed fluid F in the first dynamic pressure generating groove 163 and the second dynamic pressure generating groove 173 into the inner space S1 can be suppressed, so that dynamic pressure can be reliably generated in the first dynamic pressure generating groove 163 and the second dynamic pressure generating groove 173, and contaminants can be suppressed from flowing from the inner space S1 into the first dynamic pressure generating groove 163 and the second dynamic pressure generating groove 173.

[0103] In addition, the shape of the above-mentioned modification example 1-6 can also be applied to the sliding member of this embodiment 2.

[0104] As mentioned above, although the embodiment of the present invention is described based on the drawings, the specific structure is not limited to these embodiments, and the change or addition within the range which does not deviate from the summary of the present invention is also included in the present invention.

[0105] For example, in the above-mentioned embodiments 1, 2 and variations 1-6, the bottom of the conducting groove is tilted in the radial range and extends to the sliding surface, but it is not limited to this, as long as at least a part of the bottom of the conducting groove has an inclined surface tilted in the radial direction. Fig.14As shown, the bottom 154e of the fluid inducing groove 154 has a flat surface 154f extending from the inner diameter side end toward the outer diameter side in parallel with the flat surface of the land portion 12 and an inclined surface 154g inclined from the outer diameter side end of the flat surface 154f toward the flat surface of the land portion 12.

[0106] In the above-mentioned embodiments 1 and 2 and modified examples 1 to 6, the bottom of the conducting groove is a flat inclined surface. However, for example, the bottom may have an inclined surface that is curved in cross-sectional view.

[0107] In addition, in the above-mentioned embodiments 1, 2 and variations 1-6, the bottom of the conducting groove is illustrated as being inclined in a manner that becomes shallower from the inner diameter side (i.e., the side connected to the external space) toward the external space side (i.e., the radially closed side of the conducting groove), but is not limited to this. For example, it may also be an inclined surface that becomes shallower from the radially closed side toward the side connected to the external space.

[0108] In addition, in the above-mentioned embodiments 1, 2 and modified examples 1-6, the form in which the dynamic pressure generating groove as a whole is connected only in an area shallower than the bottom surface of the conductive groove is illustrated, but it is not limited to this. For example, it is also possible that a part of the dynamic pressure generating groove is connected to the conductive groove in an area with the same depth as the conductive groove.

[0109] In the above-mentioned embodiment, the sealed fluid is described as a high-pressure liquid, but the invention is not limited thereto and may be a gas or a low-pressure liquid, or may be a mist mixed with liquid and gas.

[0110] In the above-mentioned embodiment, the fluid on the leakage side is an example in which the atmosphere A is a low-pressure gas, but the present invention is not limited thereto and may be a liquid or a high-pressure gas, or may be a mist in which liquid and gas are mixed.

[0111] In addition, although the sealed fluid side is described as the high-pressure side and the leakage side as the low-pressure side, the sealed fluid side may be the low-pressure side and the leakage side may be the high-pressure side, or the sealed fluid side and the leakage side may be at approximately the same pressure.

[0112] In addition, in the above-mentioned embodiment, an outer-type mechanical seal is illustrated for sealing the sealed fluid F that is intended to leak from the inner diameter side of the sliding surface to the outer diameter side, but it is not limited to this, and it can also be an inner-type mechanical seal that is intended to seal the sealed fluid F that is intended to leak from the outer diameter side of the sliding surface to the inner diameter side.

[0113] In addition, in the above-mentioned embodiment, the mechanical seal used in general industrial machinery is used as an example for the sliding component, but it can also be other mechanical seals used in automobiles or water pumps. In addition, it is not limited to mechanical seals, and it can also be sliding components other than mechanical seals such as sliding bearings.

[0114] Furthermore, in the above-described embodiment, an example in which the conduction groove and the dynamic pressure generating groove are provided in the stationary seal ring is described. However, the conduction groove and the dynamic pressure generating groove may also be provided in the rotating seal ring.

[0115] In the above embodiment, eight dynamic pressure generating mechanisms having conduction grooves and dynamic pressure generating grooves are provided on the sliding surface, but the number can be freely changed. In addition, the shapes of the conduction grooves and dynamic pressure generating grooves can also be freely changed.

[0116] In the above-mentioned embodiment, the inclined surface of the conducting groove is exemplified as being inclined in the radial direction, but the present invention is not limited thereto, and the inclined surface may have a component inclined in the circumferential direction in addition to a component inclined in the radial direction.

[0117] Description of symbols

[0118] 10: stationary seal ring (sliding part); 11: sliding surface; 12: land portion (land portion); 14: dynamic pressure generating mechanism; 15: fluid induction groove (conduction groove); 15a: bottom surface (bottom); 15b: side wall portion; 15c: connecting portion (radial end portion on the external space side); 15d: radial outermost portion (radial end portion on the opposite side to the external space); 16: first dynamic pressure generating groove (dynamic pressure generating groove); 17: second dynamic pressure generating groove (dynamic pressure generating groove); 20: Rotating sealing ring (other sliding parts); 21: sliding surface; 100: stationary sealing ring (sliding part); 110: sliding surface; 120: land portion; 151-153: fluid inducing groove (conducting groove); 161-163: first dynamic pressure generating groove (dynamic pressure generating groove); 171-173: second dynamic pressure generating groove (dynamic pressure generating groove); A: atmosphere; F: sealed fluid; F1: vortex flow; S1: inner space (external space); S2: outer space (external space).

Claims

1. A sliding component, which is annular and arranged at a relatively rotating part of a rotating machine, and slides relative to other sliding components, wherein: The sliding surface of the sliding component includes: a conducting groove communicating with an external space via an opening; and a dynamic pressure generating groove, which is connected to the conducting groove, extends in the circumferential direction, and has a closed terminal portion, The bottom of the conducting groove has an inclined surface inclined in the radial direction at least in a part. The conduction groove has a protruding end portion protruding in a radial direction from the dynamic pressure generating groove to a side opposite to the opening. The protruding end is a closed end surrounded by the land portion, The dynamic pressure generating groove is entirely connected to the conducting groove at a portion shallower than the inclined surface.

2. The sliding component according to claim 1, wherein: The inclined surface is formed over the entire radial area of ​​the bottom of the conducting groove.

3. The sliding component according to claim 1 or 2, wherein: The radial end portion of the conduction groove on the external space side is wider in the circumferential direction than the end portion of the conduction groove on the radially opposite side to the external space.

4. The sliding component according to claim 1 or 2, wherein: The inclined surface is continuous with the sliding surface.

5. The sliding component according to claim 1 or 2, wherein: When viewed from the axial direction, the side wall portion of the conducting groove is in an arc shape.

6. The sliding component according to claim 1 or 2, wherein: The dynamic pressure generating groove is in communication with the external space.

7. The sliding component according to claim 1 or 2, wherein: The dynamic pressure generating groove and the external space are separated by a land portion.

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