sliding parts

Abstract

The purpose is to provide a sliding part with a small starting torque during startup. As a sliding part (10) that is positioned at a relative rotating location of a rotating machine and slides relative to another sliding part (20), the sliding part (10) is provided with a reservoir space (16) formed on the back side of the sliding surface (11) of the sliding part (10) to which a fluid (F) is introduced, and a plurality of through holes (17) communicating with the reservoir space (16) and the sliding surface (11).

Description

Technology Field

[0001] The present invention relates to a sliding component that rotates relative to another, and more specifically, to a sliding component used in a shaft sealing device for sealing a rotating shaft of, for example, an automobile, general industrial machinery, or other rotating machinery in the sealing field, or to a sliding component used in a bearing of a machine in an automobile, general industrial machinery, or other bearing field. Background Technology

[0002] As a shaft sealing device for preventing leakage of a sealed fluid, for example, a mechanical seal is equipped with a pair of annular sliding parts that rotate relative to each other and slide against each other. While such a mechanical seal can seal a high-pressure fluid, it is desired to achieve both further reduction of fluid leakage and lubricity of the sliding parts.

[0003] For example, the mechanical seal described in Patent Document 1 is configured such that a pair of annular sliding parts are rotatably connected to each other, and a through hole is provided that communicates with a pocket groove provided on the sliding surface of one of the sliding parts. This mechanical seal allows fluid to be supplied from the pocket groove to the sliding surface through the through hole, thereby applying a force that separates the sliding surfaces of the pair of sliding parts by the static pressure of the fluid, resulting in reduced leakage and excellent lubricity. Prior art literature

[0004] International Publication No. 00 / 75540 (page 5, Fig. 2) The problem to be solved

[0005] In a sliding part such as that described in Patent Document 1, a pocket groove extending from the opening of a through hole to both sides in the circumferential direction is provided so that fluid is supplied circumferentially between the sliding surfaces, but the pressure of the fluid within the pocket groove is uneven in the circumferential direction, and the fluid film formed between the sliding surfaces is prone to becoming uneven in the circumferential direction. Because of this, partial poor lubrication occurs, especially during starting at low rotational speeds, and there is a risk of causing an increase in torque or wear of the sliding surfaces.

[0006] The present invention was made by focusing on these problems and aims to provide a sliding part with low starting torque during startup. means of solving the problem

[0007] To solve the above problem, the sliding part of the present invention is,

[0008] As a sliding part positioned at a relative rotating point of a rotating machine and sliding relative to another sliding part,

[0009] The above sliding part is provided with a fluid retention space formed on the back side of the sliding surface of the sliding part and into which fluid is introduced, and a plurality of through holes communicating with the fluid retention space and the sliding surface.

[0010] According to this, when starting a rotating machine, fluid is supplied between the sliding surfaces through a plurality of through holes from the same reservoir space formed on the back side of the sliding surfaces. Consequently, since static pressure is applied evenly in the circumferential direction between the sliding surfaces, the starting torque during the starting of the rotating machine is low. In addition, it is easy to change the arrangement and shape of the plurality of through holes, making it easy to respond to the requirements for the pressure and amount of fluid supplied between the sliding surfaces.

[0011] The above-mentioned retention space may form a continuous ring in the circumferential direction of the above-mentioned sliding part.

[0012] According to this, the fluid introduced into the reservoir space becomes approximately the same pressure. For this reason, fluid of approximately the same pressure is supplied between the sliding surfaces from multiple through holes.

[0013] The above-mentioned retention space may be a cavity in which the radial cross-section of the sliding part is continuous in the circumferential direction.

[0014] According to this, since the sliding part has a tubular shape with a continuous cavity formed in the circumferential direction, the fluid storage space is difficult to be affected by the environment outside the sliding part, such as external fluids.

[0015] The above-mentioned through holes may be extended in a straight line.

[0016] According to this, fluid can be efficiently supplied from the storage space to the sliding surface.

[0017] The above through hole may be formed perpendicularly to the sliding surface.

[0018] According to this, static pressure of the fluid can be efficiently applied between the storage space and the sliding surface.

[0019] The opening on the sliding surface side of the above-mentioned through hole may be on the same surface as the sliding surface.

[0020] According to this, since the opening on the sliding surface side of the through hole is not extended in the plane direction, the through hole does not generate dynamic pressure during startup or normal operation, making it easy to maintain the initial pressure between the sliding surfaces.

[0021] A dynamic pressure generating groove may be provided on the above sliding surface.

[0022] According to this, the driving torque can be reduced from the start-up to normal operation.

[0023] The above sliding part may be a sliding part on the stop side.

[0024] According to this, since it does not rotate during startup or relative rotation during normal operation, it is difficult for fluid flow to occur within the storage space, allowing fluid to be supplied stably from the storage space to the through hole.

[0025] The above fluid may be a sealed fluid.

[0026] According to this, it is difficult for a fluid other than the fluid on the leakage side to be mixed into the sealed fluid. Brief explanation of the drawing

[0027] FIG. 1 is a cross-sectional view of a mechanical seal to which the sliding part of Example 1 according to the present invention is applied. FIG. 2 is a perspective view showing a portion of the sliding part of Example 1 according to the present invention broken apart. FIG. 3 is a front view of a sliding part of Example 1 according to the present invention. FIG. 4 is a cross-sectional view in the diameter direction of a sliding part of Example 1 according to the present invention. FIG. 5 is a cross-sectional view in the radial direction showing a modified example of a sliding part of Example 1 according to the present invention. FIG. 6 (a) is a front view showing a sliding part of Example 2 according to the present invention, and (b) is a cross-sectional view in the diameter direction of the said sliding part. FIG. 7 (a) is a front view showing a sliding part of Example 3 according to the present invention, and (b) is a cross-sectional view in the diameter direction of the sliding part. FIG. 8 is a front view of a sliding part of Example 4 according to the present invention. Fig. 9 is a cross-sectional view of AA in Fig. 8. Figure 10 is a cross-sectional view of BB in Figure 8. FIG. 11 is a radial cross-sectional view illustrating another form 1 of a sliding part according to the present invention. FIG. 12 is a radial cross-sectional view illustrating another form 2 of a sliding part according to the present invention. Specific details for implementing the invention

[0028] A form for implementing a sliding part according to the present invention is described below based on an example.

[0029] Example 1

[0030] A mechanical seal to which a sliding component according to Example 1 is applied will be described with reference to FIGS. 1 to 5. In addition, in this embodiment, the outer diameter side of the sliding component constituting the mechanical seal will be described as the fluid to be sealed side and the inner diameter side as the atmosphere side. Furthermore, the sliding surface side of the sliding component will be described as the front side and the side opposite to the sliding surface as the back side.

[0031] The mechanical seal (M) for a rotating machine shown in FIG. 1 is an inside type that seals the high-pressure fluid to be sealed (F) on the outer diameter side from leaking into the atmosphere (A) on the inner diameter side from the outer diameter side. In addition, the fluid to be sealed (F) may be a liquid or a gas.

[0032] The mechanical seal (M) is mainly composed of a stationary sealing ring (10) as a circular sliding part and a rotating sealing ring (20) as another circular sliding part. The stationary sealing ring (10) is provided in a non-rotating state and axially movable state on a seal cover (4, 5) fixed to a housing of the device to be mounted. The rotating sealing ring (20) is mounted on a rotating shaft (1) through a sleeve (2), and the rotating sealing ring (20) is configured to rotate integrally with the rotating shaft (1). In addition, the mechanical seal (M) is configured such that the sliding surface (11) of the stationary sealing ring (10) and the sliding surface (21) of the rotating sealing ring (20) slide closely together by the axially attaching the stationary sealing ring (10) by a coil spring (7). In addition, the sliding surface (21) of the rotating sealing ring (20) is a flat surface, but a groove or the like may be formed therein.

[0033] The stationary seal ring (10) and the rotating seal ring (20) are typically formed from SiC (hard material) or a combination of SiC (hard material) and carbon (soft material). Furthermore, the sliding material is not limited to this, and any sliding material used as a mechanical seal sliding material can be applied. For example, as a hard material, ceramics other than SiC, carbon, metal materials, resin materials, surface modification materials (coating materials), composite materials, etc., can also be applied.

[0034] Referring to FIGS. 2 to 4, the stop seal ring (10) is an annular body in which an annular cavity is formed as a storage space (16) inside. Additionally, when viewed from a planar perspective, the stop seal ring (10) is an annular shape, and the cross-section in the radial direction is formed in the shape of a rectangular frame. The stop seal ring (10) is manufactured by an additive manufacturing method using a 3D printer, which is a type of additive manufacturing device, but it may also be made by other manufacturing methods.

[0035] The stop sealing ring (10) is provided with an annular front side wall (12), a cylindrical outer diameter side wall (13), an annular rear side wall (14), and a cylindrical inner diameter side wall (15). The front side wall (12) has a sliding surface (11). The outer diameter side wall (13) extends axially in a manner approximately orthogonal to the outer diameter end of the front side wall (12). The rear side wall (14) is positioned opposite the front side wall (12) in a manner approximately orthogonal to the rear end of the outer diameter side wall (13). The inner diameter side wall (15) extends axially in a manner approximately orthogonal to the inner diameter end of the rear side wall (14) and the inner diameter end of the front side wall (12).

[0036] In this embodiment, the wall portions (13-15) are formed with approximately the same thickness dimension at the portions facing the storage space (16). Additionally, the thickness dimension of the front side wall portion (12) is formed to be larger than the thickness dimension of the wall portions (13-15).

[0037] In addition, in the stop sealing ring (10), a rectangular or circular storage space (16) is formed by the wall portions (12-15) and is continuous in the circumferential direction. The cross-sectional area of ​​the flow path in the diameter direction of the storage space (16) is approximately the same and is continuous in the circumferential direction.

[0038] As shown in FIGS. 2 to 4, a plurality of through holes (17) are formed in the front side wall (12). The through holes (17) penetrate the front side wall (12) approximately perpendicular to the sliding surface (11) and are connected to the storage space (16) and the sliding surface (11), respectively. Each through hole (17) has a straight shape that extends in the axial direction and is circular when viewed from a plane. Additionally, each through hole (17) has a flow path cross-sectional area in the radial direction that is approximately the same and extends axially from the storage space (16) to the opening (17a).

[0039] A plurality of through holes (17) are arranged in a so-called zigzag pattern, with the diameter positions of adjacent through holes (17) along the circumferential direction being spaced at predetermined intervals. Additionally, a plurality of through holes (17) are arranged on the outer diameter side of the sliding surface (11) in the diameter direction. Furthermore, the through holes (17) are formed together when forming the stop seal ring (10) using a 3D printer, but they may also be formed by drilling with a drill, laser, etc.

[0040] Additionally, as shown in FIGS. 3 and 4, the through hole (17) has an opening (17a) on the sliding surface (11) side formed to be in line with the sliding surface (11). Also, the axial dimensions of each through hole (17) are formed to be approximately the same.

[0041] In the outer diameter side wall (13), one pressure introduction part (18), which is a through hole penetrating in the thickness direction, is formed.

[0042] Next, the supply of a sealing fluid (F) between sliding surfaces (11, 21) during stopping, starting, and normal operation of a rotating machine to which a mechanical seal (M) is applied will be explained with reference to FIG. 1 and FIG. 2.

[0043] Referring to FIG. 1, when the rotating machine is stopped, that is, when the rotating shaft (1) is stopped, the sum of the negative force of the coil spring (7) and the pressure of the fluid to be sealed (F) acts in a direction that brings the sliding surfaces (11, 21) relatively closer. On the other hand, the opening (17a) of the through hole (17) faces the sliding surface (21), and the force due to the positive pressure of the fluid to be sealed (F) acts in a direction that separates the sliding surfaces (11, 21) relatively.

[0044] Since the force in the direction of bringing the sliding surfaces (11, 21) closer is greater than the force in the direction of separating them, the sliding surfaces (11, 21) are in contact. Therefore, the fluid to be sealed (F) is prevented from leaking to the atmosphere (A).

[0045] In addition, between the sliding surfaces (11, 21) when stopped, there is a small amount of fluid to be sealed (F), and at the same time, the fluid to be sealed (F) is easily entered not only from the outer diameter ends of the sliding surfaces (11, 21) but also from each through hole (17) through capillary action, etc.

[0046] In addition, since the plurality of through holes (17) are formed approximately equally over the circumferential direction of the sliding surface (11), the fluid to be sealed (F) can be supplied approximately evenly over the circumferential direction between the sliding surfaces (11, 21).

[0047] Additionally, within the storage space (16), the fluid to be sealed (F) is supplied through the pressure inlet (18), as indicated by the black thin arrow in FIG. 2. Because of this, the flow direction of the fluid to be sealed (F) from the pressure inlet (18) is difficult to directly affect the flow in the through hole (17). Furthermore, the fluid to be sealed (F) can be stably filled within the storage space (16).

[0048] When the rotating machine is stopped and started, the fluid to be sealed (F) is supplied through each through hole (17) so that it flows slightly between the sliding surfaces (11, 21), as indicated by the thick black arrow in FIG. 2. In this way, when the machine is stopped and started, the static pressure of the fluid to be sealed (F) from the through hole (17) acts on the sliding surface (21), and the fluid to be sealed (F) is supplied between the sliding surfaces (11, 21), thereby appropriately reducing the load on the sliding surface and providing excellent lubricity.

[0049] After that, the rotational speed of the rotating shaft (1) increases, and even when the rotational speed becomes the normal operating speed of the rotating machine, the static pressure of the fluid to be sealed (F) from the through hole (17) acts on the sliding surface (21), so that the fluid to be sealed (F) can be supplied to flow out between the sliding surfaces (11, 21) through each through hole (17).

[0050] As described above, in the case of the stationary sealing ring (10) of the present embodiment 1, the fluid to be sealed (F) introduced into the storage space (16) has a circular shape that is continuous in the circumferential direction, so that the fluid to be sealed (F) introduced into the storage space (16) has approximately the same pressure. Because of this, the fluid to be sealed (F) with approximately the same pressure is supplied between the sliding surfaces (11, 21) from a plurality of through holes (17).

[0051] Additionally, the fluid storage space (16) is positioned so that only the thickness of the front side wall (12) exists between the sliding surface (11) and the fluid storage space (16), that is, the fluid storage space (16) is positioned directly below the sliding surface (11). In this respect, the sealed fluid (F) supplied from the fluid storage space (16) to the sliding surface (11) through the through hole (17) has a small pressure loss, etc.

[0052] Additionally, the storage space (16) is formed by walls (12-15) that form a rectangular frame shape when viewed from a cross-sectional view in the radial direction. Additionally, the storage space (16) is a cavity with a continuous cross-sectional view in the radial direction. In other words, since the stationary sealing ring (10) is a tubular shape with a cavity formed continuously in the circumferential direction, the inside of the storage space (16) is less susceptible to the influence of the environment outside the stationary sealing ring (10), such as turbulence of the fluid to be sealed (F) outside the stationary sealing ring (10), and thus it is easier to maintain the pressure inside the storage space (16) approximately equally.

[0053] In addition, the storage space (16) has a flow path cross-sectional area in the radial direction that is approximately the same and is continuous in the circumferential direction. Because of this, compared to a configuration where the flow path cross-sectional area in the radial direction varies, it is easy to maintain the pressure within the storage space (16) approximately the same in the circumferential direction.

[0054] In addition, only one pressure introduction section (18) is formed. In this respect, compared to a configuration in which multiple sections are formed, the effect of supplying the sealed fluid (F) into the storage space (16) can be reduced.

[0055] In addition, the through hole (17) is connected in a straight line, so pressure loss can be reduced compared to a configuration that is connected in a broken line shape or a curved shape. Because of this, the fluid to be sealed (F) can be efficiently supplied from the storage space (16) to the sliding surface (11, 21).

[0056] In addition, the through hole (17) is formed in a circular shape when viewed from the cross-section. Because of this, pressure loss can be reduced compared to a configuration in which it is formed in a polygonal shape when viewed from the cross-section.

[0057] Additionally, the through hole (17) has a flow path cross-sectional area that is approximately the same across the direction of the flow path. Because of this, pressure loss can be reduced compared to configurations where the flow path cross-sectional area varies.

[0058] Additionally, since each through hole (17) has approximately the same axial dimension, the pressure loss that occurs as the fluid to be sealed (F) passes through the through hole (17) is approximately the same. Accordingly, it is easy to make the static pressure of the fluid to be sealed (F) flowing out from each through hole (17) approximately the same.

[0059] In addition, since the inner surface (17b) of each through hole (17) extends axially perpendicular to the sliding surface (11), pressure loss can be reduced compared to a configuration in which the inner surface of the through hole extends at an angle relative to the sliding surface (11). Because of this, it is easy to make the pressure and flow rate of the sealed fluid (F) supplied through each through hole (17) approximately equal.

[0060] Due to these points, the pressure distribution in the circumferential direction between the sliding surfaces (11, 21) becomes approximately uniform. Because of this, the relative rotation between the stationary seal ring (10) and the rotating seal ring (20) can be stabilized.

[0061] Additionally, the through hole (17) is formed perpendicularly to the sliding surface (11). Because of this, compared to a configuration where the through hole is inclined relative to the sliding surface (11), it is easier to apply static pressure in a direction approximately perpendicular to the sliding surface (21) of the rotating sealing ring (20), that is, in a direction approximately the same as the direction that relatively separates the sliding surfaces (11, 21). Accordingly, static pressure of the fluid to be sealed (F) can be efficiently applied from the storage space (16) to the sliding surfaces (11, 21).

[0062] Additionally, the through hole (17) has an opening (17a) formed in alignment with the sliding surface (11), so that, for example, there is no continuous pocket groove extending in the circumferential direction in the opening of the through hole, the through hole (17) does not generate dynamic pressure during normal operation when rotation is at high speed, and is easy to maintain at the initial pressure between the sliding surfaces (11, 21).

[0063] Additionally, the stationary sealing ring (10), having a storage space (16), a through hole (17), and a pressure introduction part (18), is provided in a stationary state that does not rotate. Since the stationary sealing ring (10) does not rotate during startup or relative rotation during normal operation, it is difficult for flow to occur in the fluid to be sealed (F) within the storage space (16), so the fluid to be sealed (F) can be stably supplied from the storage space (16) to the through hole (17).

[0064] Additionally, each through hole (17) is formed on the outer diameter side of the sliding surface (11). Compared to a configuration where each through hole (17) is formed on the inner diameter side of the sliding surface (11), the distance from each through hole (17) to the atmosphere (A) side is longer. Accordingly, not only is leakage of the fluid to be sealed (F) prevented, but the area in which the fluid to be sealed (F) can be supplied in the diameter direction can also be widened.

[0065] In addition, since it is easy to change the arrangement and shape of the multiple through holes (17), it is easy to respond to the requirements for the pressure and amount of fluid supplied between the sliding surfaces (11, 21).

[0066] Additionally, each through hole (17) is arranged in a zigzag pattern. In this respect, compared to the configuration in which the same number of through holes of the present embodiment are arranged on a single circle along the circumferential direction, it is possible to arrange adjacent through holes (17) in close proximity to each other. Accordingly, many through holes (17) can be arranged while maintaining the structural strength of the stop sealing ring (10). Furthermore, since the through holes (17) can be arranged densely, the pressure balance in the circumferential direction between the sliding surfaces (11, 21) is good.

[0067] Additionally, each through hole (17) is a through hole formed in the front side wall (12). Because of this, the structure can be simplified compared to a configuration in which a separate orifice is mounted on the stop sealing ring (10).

[0068] Additionally, the pressure inlet (18) is positioned so as to be located on the vertically downward side of the mechanical seal (M) (see FIG. 1). Because of this, even if dust or other debris is mixed in the fluid to be sealed (F), it is difficult for it to enter the storage space (16) through the pressure inlet (18). Furthermore, even if the fluid to be sealed (F) mixed with dust or other debris enters the storage space (16), it sinks due to gravity and is easily discharged from the pressure inlet (18). In this respect, blockage of the through hole (17) can be prevented. Moreover, the stationary sealing ring (10) is provided in a stationary state that does not rotate. Therefore, the position of the pressure inlet (18) can be maintained.

[0069] In addition, in this embodiment, the pressure introduction part (18) is described as being formed on the outer diameter side wall (13) of the stop seal ring (10), but it is not limited thereto, and the pressure introduction part (118) may be formed on the back side wall (14) as in the stop seal ring (10A) shown in FIG. 5, and may be appropriately modified.

[0070] Additionally, the stop seal ring may have multiple pressure introduction parts (18) or pressure introduction parts (118) formed therein, for example, one pressure introduction part (18) and one pressure introduction part (118) may be formed therein or multiple pressure introduction parts each may be formed therein.

[0071] Additionally, the axial dimension of the through hole (17), in other words, the thickness dimension of the front side wall (12), may be appropriately changed. Accordingly, the static pressure of the fluid to be sealed (F) supplied between the sliding surfaces (11, 21) can be controlled by utilizing the pressure loss when the fluid to be sealed (F) passes through the through hole (17).

[0072] Example 2

[0073] Next, Example 2 of the sliding part will be described with reference to FIG. 6. In addition, descriptions of configurations identical to or overlapping with Example 1 will be omitted.

[0074] As shown in FIG. 6(a), a plurality of through holes (171), through holes (172), through holes (173), and through holes (174) are formed in the stop seal ring (110) from the outer diameter side toward the inner diameter side.

[0075] As shown in FIG. 6(b), the front side wall (120) has a slanted back surface (121), and its thickness dimension gradually increases from the outer diameter side toward the inner diameter side. In this respect, the axial dimensions of the through holes (171 to 174) are such that the through hole (171) is the shortest. Additionally, the lengths become longer in the order of through hole (172) and through hole (173), with the through hole (174) being the longest.

[0076] Accordingly, the stop seal ring (110) has through holes (171-174) formed in a wide area in the diameter direction compared to the stop seal ring (10) of Example 1. In this respect, the fluid to be sealed (F) can be supplied more stably between the sliding surfaces (111, 21).

[0077] In addition, the through holes (171-174) have longer axial dimensions the closer they are to the inner diameter side. In this respect, the pressure loss is greater the closer they are to the inner diameter side. In other words, the static pressure of the fluid to be sealed (F) supplied between the sliding surfaces (111, 21) through the through hole closer to the inner diameter side is reduced, so the static pressure of the fluid to be sealed (F) between the sliding surfaces (111, 21) is greater on the outer diameter side than on the inner diameter side. In this way, it is possible to achieve both a reduction in leakage amount and an improvement in lubricity.

[0078] Example 3

[0079] Next, Example 3 of the sliding part will be described with reference to FIG. 7. In addition, descriptions of configurations identical to or overlapping with Examples 1 and 2 will be omitted.

[0080] As shown in FIG. 7, a plurality of spiral-shaped dynamic pressure generating grooves (19) are formed on the sliding surface (211) of the stationary sealing ring (210). The dynamic pressure generating grooves (19) extend from the inner diameter side end of the stationary sealing ring (210) toward the outer diameter side while curving along the rotational direction of the rotating sealing ring (20). Additionally, each dynamic pressure generating groove (19) is arranged at predetermined intervals along the circumferential direction of the sliding surface (211).

[0081] Referring to FIG. 7(a), the dynamic pressure generating groove (19) can generate dynamic pressure by concentrating the fluid that flows into the dynamic pressure generating groove (19) by the same rotation at the acute angle-shaped corner portion (19a) located on the outer diameter side and also on the rotational direction side of the rotating seal ring (20).

[0082] Accordingly, during low-speed rotation when starting the rotating machine, the static pressure of the sealing fluid (F) supplied between the sliding surfaces (211, 21) through the through hole (17) as in Example 1 above acts as the primary force separating the sliding surfaces (211, 21). On the other hand, during high-speed rotation during normal operation, the dynamic pressure from the dynamic pressure generating groove (19) acts as the primary force separating the sliding surfaces (211, 21) slightly. In this way, the driving torque can be reduced from the start to normal operation.

[0083] Example 4

[0084] Next, Example 4 of the sliding part will be described with reference to FIGS. 8 to 10. In addition, descriptions of configurations identical to or overlapping with Examples 1 to 3 will be omitted.

[0085] As shown in FIG. 8, openings (17a, 217a) of through holes (17, 217) (see FIG. 9, FIG. 10) are arranged in a zigzag pattern on the sliding surface (311) of the stop seal ring (310). The openings (17a, 217a) are arranged along the circumferential direction on the outer diameter side of the sliding surface (311).

[0086] Referring to FIGS. 9 and 10, the opening (217c) communicating with the reservoir space (16) of the through hole (217) is alternately arranged and formed on the same circle as the opening (17c) communicating with the reservoir space (16) of the through hole (17). The through hole (217) is inclined outward from the opening (217c) and extends in a straight line toward the sliding surface (311). Additionally, the through hole (217) is continuous with the opening (217a) of the sliding surface (311).

[0087] Accordingly, the opening (217a) of the through hole (217) can be positioned on the outer diameter side, that is, on the side of the fluid to be sealed (F), rather than the storage space (16). Because of this, the distance to the atmosphere (A) side is longer compared to Example 1. Therefore, not only is leakage of the fluid to be sealed (F) prevented, but the area where the fluid to be sealed (F) can be supplied in the diameter direction can also be widened.

[0088] Additionally, the through hole (217) is inclined and has an axial dimension longer than the axial dimension of the through hole (17), and has a greater pressure loss than the through hole (17). Furthermore, since a small static pressure is supplied to the sliding surface (311), it is difficult for the fluid to be sealed (F) to leak out.

[0089] Additionally, the opening (217a) of the through hole (217) is formed in alignment with the sliding surface (311). Because of this, dynamic pressure is not generated during normal operation when rotation is at high speed, making it easy to maintain the initial pressure between the sliding surfaces (311, 21).

[0090] Although embodiments of the present invention have been described above with reference to the drawings, the specific configuration is not limited to these embodiments, and changes or additions within the scope that do not deviate from the gist of the present invention are also included in the present invention.

[0091] For example, in the above embodiment, the sliding part was described as being configured to be applied to a mechanical seal, but is not limited thereto and may be applied to a component other than a mechanical seal, such as a sliding bearing.

[0092] In addition, although the mechanical seal was described as an inside type, it is not limited to this and an outside type is also acceptable.

[0093] In addition, although the fluid to be sealed was described as a high-pressure liquid, it is not limited to this; it may be a mist state in which liquid and gas are mixed, a gas, or a low-pressure fluid.

[0094] In addition, although it was explained that the fluid on the leakage side is the atmosphere, it is not limited to this; it may be a liquid, a mist in which liquid and gas are mixed, or a fluid at a higher pressure than the fluid to be sealed.

[0095] In addition, the sliding part in which the retention space and through hole are formed has been described as having a configuration of a stationary sealing ring, but is not limited thereto and may also be a rotating sealing ring.

[0096] Additionally, although the storage space has been described as being formed by walls arranged on all sides, it is not limited thereto. As shown in FIG. 11, the back side between the outer diameter side wall (13) and the inner diameter side wall (15) may be open, and the storage space (216) formed by each wall (12, 13, 15) may be directly connected to the back side of the storage space (310). In such a configuration, it is desirable to narrow the flow path connecting to the back side of the storage space (216) using a housing, case, etc., thereby making it difficult for the external fluid to influence the fluid inside the storage space (216).

[0097] In addition, although the storage space has been described as being formed by walls arranged in a rectangular frame shape when viewed from the cross-section, it is not limited to this, and may be in a polygonal frame shape other than a rectangular frame, may be in a D-shape when viewed from the cross-section with C-shaped walls continuing with the front side wall, or may have the cross-sectional shape appropriately changed as long as the walls are arranged in a tubular shape.

[0098] In addition, although the storage space has been described as having a rectangular shape when viewed from the cross-section, it is not limited to this and may be of other polygonal or circular shapes, or may be appropriately modified.

[0099] In addition, although the storage space has been described as having a continuous configuration in the perimeter direction, it is not limited thereto and may be formed in multiple sections in the perimeter direction; in this case, it is preferable to have a connecting hole formed to connect the storage space adjacent to the sectioning wall. Furthermore, the cross-sectional area of ​​the flow path in the perimeter direction may vary.

[0100] Additionally, the stop seal ring may be formed from a plurality of members. For example, it may be formed by fixing a separate cover member (114) to a substrate having wall portions (12, 13, 15), such as the stop seal ring (510) shown in FIG. 12.

[0101] In addition, although the through hole was described as having a configuration that runs in a straight line, it is not limited to this; as long as it is connected to the sliding surface and the storage space, it may have a curved shape, or it may have at least one bend, and it may be appropriately modified.

[0102] Additionally, although the through holes were described as being arranged in a zigzag shape, they are not limited to this configuration; they may be arranged in a single line, arranged in parallel along the same radial direction, or modified as appropriate.

[0103] In addition, although the through holes have been described as being arranged at predetermined intervals, they are not limited thereto and may be arranged regularly at non-predetermined intervals or irregularly.

[0104] In addition, although the through hole was described as having a circular shape when viewed from the cross-section, it is not limited thereto; it may be polygonal or star-shaped, and its shape may be appropriately modified.

[0105] In addition, although it was explained that the through holes have a configuration where the cross-sectional area of ​​the flow path is approximately the same, they are not limited to this and may vary.

[0106] In addition, although the fluid was described as a sealed fluid, it is not limited to this and may be any fluid other than the sealed fluid supplied through the pressure inlet.

[0107] In addition, although the dynamic pressure generating groove was described as having a spiral shape, it is not limited to this, and may be, for example, a Rayleigh step groove which is a positive dynamic pressure generating groove, a reverse Rayleigh groove which is a negative dynamic pressure generating groove, a herringbone groove, a rectangular groove, a dimple, etc., or a combination thereof, or may be appropriately modified. Explanation of the symbols

[0108] 10, 10A; Stop seal ring (sliding part) 11; sliding surface 16; Retention space (cavity) 17; through hole 17a; opening (opening on the sliding surface side) 18; pressure introduction section 19; Dynamic pressure generating groove 20; Rotating seal ring (other sliding parts) 21; sliding surface 110~510; Stop seal ring (sliding part) 111~311; Sliding surface 118; pressure introduction section 171~174; through holes 216; Retention space 217; through hole A; Waiting F; sealed fluid (fluid) M; Mechanical Seal

Claims

Claim 1 A sliding part disposed at a relative rotating location of a rotating machine and sliding relative to another sliding part to seal a space on the fluid side to be sealed and a space on the leakage side, wherein the sliding part is provided with a retention space formed by being surrounded by a wall portion of the sliding part on the back side of the sliding surface of the sliding part, a pressure inlet portion formed through in the thickness direction of the sliding part and through which the fluid to be sealed is supplied to the retention space, and a plurality of through holes communicating with the retention space and the sliding surface. Claim 2 In claim 1, the above-mentioned reservoir space is a sliding part that forms a ring continuously in the circumferential direction of the sliding part. Claim 3 In claim 1 or 2, the above-mentioned reservoir space is a sliding part in which the radial cross-section of the sliding part is continuous in the circumferential direction. Claim 4 In claim 1 or 2, the through hole is a sliding part that extends in a straight line. Claim 5 In claim 1 or 2, the through hole is a sliding part that is orthogonal to the sliding surface. Claim 6 In claim 1 or 2, the opening on the sliding surface side of the through hole is a sliding part that is plane-like with the sliding surface. Claim 7 A sliding part according to claim 1 or 2, wherein a dynamic pressure generating groove is provided on the sliding surface. Claim 8 In claim 1 or 2, the sliding part is a sliding part that is a sliding part on the stop side. Claim 9 delete

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