Sliding part

Abstract

The purpose of the present invention is to provide a sliding component with a low starting torque at start up.　A sliding component 10 is disposed in a relatively rotating location of a rotary machine and relatively slides with another sliding component 20 and the sliding component 10 includes; a reservoir space 16, which is formed on the rear side of a sliding surface 11 of the sliding component 10 and into which a fluid F is introduced; and a plurality of through holes 17 connecting the reservoir space 16 and the sliding surface 11.

Description

Technical Field

[0001] The present invention relates to sliding parts that rotate relative to each other, and is used, for example, for sliding parts used in a shaft sealing device that seals the rotating shaft of a rotating machine in the field of automobiles, general industrial machines, or other sealing fields, or for sliding parts used in bearings of machines in the field of automobiles, general industrial machines, or other bearing fields.

Background Art

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

[0003] For example, the mechanical seal shown in Patent Document 1 is configured such that a pair of annular sliding parts can rotate relative to each other, and a through hole communicating with a pocket groove provided on the sliding surface of one of the sliding parts is provided. This mechanical seal supplies fluid from the pocket groove to the sliding surface through the through hole, and applies a force in a direction to separate the sliding surfaces of the pair of sliding parts by the static pressure of the fluid, resulting in excellent leakage reduction and lubricity.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the case of sliding parts such as those in Patent Document 1, although fluid is supplied in the circumferential direction across the sliding surfaces by providing pocket grooves extending from the opening of the through-hole to both sides in the circumferential direction, the pressure of the fluid in the pocket grooves is non-uniform in the circumferential direction, and the fluid film formed between the sliding surfaces tends to be non-uniform in the circumferential direction. Therefore, especially at the start when the rotational speed is low, partial poor lubrication occurs, which may cause an increase in torque and wear of the sliding surfaces.

[0006] The present invention has been made paying attention to such problems, and an object thereof is to provide a sliding part with a small starting torque at the start.

Means for Solving the Problems

[0007] In order to solve the above problems, the sliding part of the present invention is a sliding part that is arranged at a relatively rotating part of a rotating machine and relatively slides with another sliding part, the sliding part is provided with a storage space formed on the back side of the sliding surface of the sliding part into which fluid is introduced, and a plurality of through-holes communicating with the storage space and the sliding surface. According to this, at the start of the rotating machine, fluid is supplied between the sliding surfaces through a plurality of through-holes from the same storage space formed on the back side of the sliding surface. As a result, a static pressure acts evenly in the circumferential direction between the sliding surfaces, so the starting torque at the start of the rotating machine is small. In addition, it is easy to change the arrangement and shape of the plurality of through-holes, and it is easy to meet the requirements for the pressure and amount of fluid supplied between the sliding surfaces.

[0008] The storage space may be annular and continuous in the circumferential direction of the sliding part. According to this, the fluid introduced into the storage space becomes substantially the same pressure. Therefore, fluid of substantially the same pressure is supplied between the sliding surfaces from a plurality of through-holes.

[0009] The storage space may be a cavity whose radial cross-section of the sliding part is continuous in the circumferential direction. According to this, since the sliding part is cylindrical with a cavity formed continuously in the circumferential direction, the inside of the storage space is less likely to be affected by the environment outside the sliding part, such as external fluid.

[0010] The through-hole may extend linearly. According to this, fluid can be efficiently supplied from the storage space to between the sliding surfaces.

[0011] The through-hole may extend perpendicular to the sliding surface. According to this, the static pressure of the fluid can be efficiently applied from the storage space to between the sliding surfaces.

[0012] The opening of the through-hole on the sliding surface side may be flush with the sliding surface. According to this, since the opening of the through-hole on the sliding surface side does not extend in the plane direction, the through-hole does not generate dynamic pressure during start-up or normal operation, and it is easy to maintain the initial pressure between the sliding surfaces.

[0013] A dynamic pressure generating groove may be provided on the sliding surface. According to this, the driving torque can be reduced from start-up to normal operation.

[0014] The sliding part may be a stationary-side sliding part. According to this, since it does not rotate during relative rotation at start-up and normal operation, the fluid in the storage space is less likely to flow, and the fluid can be stably supplied from the storage space to the through-hole.

[0015] The fluid may be a fluid to be sealed. According to this, it is difficult for other fluids other than the fluid on the leakage side to mix into the fluid to be sealed.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Mode for Carrying Out the Invention

[0017] A mode for carrying out the sliding part according to the present invention will be described below based on examples.

Examples

[0018] Regarding the mechanical seal to which the sliding part according to Example 1 is applied, it will be described with reference to FIGS. 1 to 5. In this example, the outer diameter side of the sliding part constituting the mechanical seal is described as the fluid side to be sealed, and the inner diameter side is described as the atmosphere side. Furthermore, the sliding surface side of the sliding part is described as the front side, and the opposite side facing the sliding surface is described as the back side.

[0019] The mechanical seal M for a rotating machine shown in Fig. 1 is an inside type that seals the leakage of the high-pressure fluid F on the outer diameter side into the atmosphere A from the outer diameter side to the inner diameter side. Note that the fluid F to be sealed may be a liquid or a gas.

[0020] The mechanical seal M is mainly composed of a stationary seal ring 10 as an annular sliding part and a rotating seal ring 20 as another annular sliding part. The stationary seal ring 10 is provided in a non-rotating and axially movable state on seal covers 4 and 5 fixed to the housing of the equipment to be attached. The rotating seal ring 20 is attached to the rotating shaft 1 via a sleeve 2, and the rotating seal ring 20 can rotate integrally with the rotating shaft 1. Also, in the mechanical seal M, the stationary seal ring 10 is axially biased by a coil spring 7, so that the sliding surface 11 of the stationary seal ring 10 and the sliding surface 21 of the rotating seal ring 20 closely slide against each other. Note that the sliding surface 21 of the rotating seal ring 20 is a flat surface, but grooves or the like may be formed.

[0021] The stationary seal ring 10 and the rotating seal ring 20 are typically formed of SiC (hard material) against SiC (hard material) or a combination of SiC (hard material) and carbon (soft material). Note that this is not limiting, and any sliding material can be applied as long as it is used as a sliding material for mechanical seals. For example, as hard materials, ceramics other than SiC, carbon, metal materials, resin materials, surface modification materials (coating materials), composite materials, etc. are also applicable.

[0022] Referring to Figs. 2 to 4, the stationary seal ring 10 is an annular body in which an annular cavity serving as a storage space 16 is formed inside. Also, the stationary seal ring 10 is formed in an annular shape in plan view and a rectangular frame shape in a radial cross section. The stationary seal ring 10 is manufactured by a layer manufacturing method using a 3D printer, which is a type of additive manufacturing device, but it may be created by other manufacturing methods.

[0023] The stationary seal ring 10 includes an annular front side wall portion 12, a cylindrical outer diameter side wall portion 13, an annular rear side wall portion 14, and a cylindrical inner diameter side wall portion 15. The front side wall portion 12 has a sliding surface 11. The outer diameter side wall portion 13 extends in the axial direction substantially orthogonally to the outer diameter side end portion of the front side wall portion 12. The rear side wall portion 14 is disposed opposite to the front side wall portion 12 substantially orthogonally to the rear side end portion of the outer diameter side wall portion 13. The inner diameter side wall portion 15 extends in the axial direction substantially orthogonally to the inner diameter side end portion of the rear side wall portion 14 and the inner diameter side end portion of the front side wall portion 12.

[0024] In this embodiment, the wall portions 13 to 15 are formed with substantially the same thickness dimension at the locations facing the storage space 16. Also, the thickness dimension of the front side wall portion 12 is larger than the thickness dimensions of the wall portions 13 to 15.

[0025] Further, in the stationary seal ring 10, a storage space 16 that is defined by the wall portions 12 to 15 and is rectangular in cross-section and annular in the circumferential direction is formed. The radial flow path cross-sectional area of the storage space 16 is substantially the same and is continuous in the circumferential direction.

[0026] As shown in FIGS. 2 to 4, a plurality of through holes 17 are formed in the front side wall portion 12. The through holes 17 penetrate the front side wall portion 12 substantially orthogonally to the sliding surface 11 and communicate with the storage space 16 and the sliding surface 11, respectively. Each through hole 17 has a linear shape extending in the axial direction and a circular shape in plan view. Also, each through hole 17 has substantially the same radial flow path cross-sectional area and is continuous in the axial direction from the storage space 16 to the opening 17a.

[0027] The plurality of through holes 17 are arranged in a so-called staggered arrangement in which the radial positions of adjacent through holes 17 are arranged at a predetermined interval over the circumferential direction. Also, the plurality of through holes 17 are arranged on the outer diameter side in the radial direction of the sliding surface 11. Note that the through holes 17 are formed together when forming the stationary seal ring 10 using a 3D printer, but may be formed by drilling with a drill, a laser, or the like.

[0028] Further, as shown in FIGS. 3 and 4, in the through hole 17, the opening 17a on the sliding surface 11 side is formed flush with the sliding surface 11. Further, the axial dimensions of the respective through holes 17 are also substantially the same.

[0029] One pressure introduction portion 18, which is a through hole penetrating in the thickness direction, is formed in the outer diameter side wall portion 13.

[0030] Next, with reference to FIGS. 1 and 2, the supply of the fluid F to be sealed between the sliding surfaces 11 and 21 at the time of stopping, starting, and normal operation of the rotating equipment to which the mechanical seal M is applied will be described.

[0031] Referring to FIG. 1, at the time of stopping the rotating equipment, that is, when the rotating shaft 1 stops, the sum of the biasing force of the coil spring 7 and the pressing force due to the pressure of the fluid F to be sealed acts in a direction to relatively bring the sliding surfaces 11 and 21 closer. On the other hand, the opening 17a of the through hole 17 faces the sliding surface 21, and the force due to the static pressure of the fluid F to be sealed acts in a direction to relatively separate the sliding surfaces 11 and 21.

[0032] Since the force in the direction to bring the sliding surfaces 11 and 21 closer is greater than the force in the direction to separate them, the sliding surfaces 11 and 21 are in contact. Therefore, leakage of the fluid F to be sealed to the atmosphere A side is prevented.

[0033] Also, between the sliding surfaces 11 and 21 at the time of stopping, a small amount of the fluid F to be sealed exists, and the fluid F to be sealed can easily enter not only from the outer diameter ends of the sliding surfaces 11 and 21 but also from each through hole 17 due to capillary action or the like.

[0034] In addition, since the plurality of through holes 17 are formed in a substantially equal distribution over the circumferential direction of the sliding surface 11, the fluid F to be sealed can be supplied substantially evenly over the circumferential direction between the sliding surfaces 11 and 21.

[0035] In addition, as shown by the black thin arrow in Fig. 2, the fluid F to be sealed is supplied into the storage space 16 through the pressure introduction part 18. Therefore, the flow direction of the fluid F to be sealed from the pressure introduction part 18 hardly directly affects the flow in the through hole 17. Furthermore, the storage space 16 can be stably filled with the fluid F to be sealed.

[0036] When the rotating equipment is stationary and starting, the fluid F to be sealed is supplied through each through hole 17 so as to slightly flow out between the sliding surfaces 11 and 21 as shown by the thick black arrow in Fig. 2. Thus, at the time of stationary and low-speed rotation at the start, the static pressure of the fluid F to be sealed from the through hole 17 acts on the sliding surface 21, the fluid F to be sealed is supplied between the sliding surfaces 11 and 21, and the load on the sliding surface is appropriately reduced, and the lubricity is excellent.

[0037] After that, even when the rotational speed of the rotating shaft 1 increases and reaches the rotational speed during normal operation of the rotating equipment, the static pressure of the fluid F to be sealed from the through hole 17 acts on the sliding surface 21, and the fluid F to be sealed can be supplied through each through hole 17 so as to flow out between the sliding surfaces 11 and 21.

[0038] As described above, in the stationary seal ring 10 of the first embodiment, since the storage space 16 is annular and continuous in the circumferential direction, the fluid F to be sealed introduced into the storage space 16 has substantially the same pressure. Therefore, the fluid F to be sealed with substantially the same pressure is supplied between the sliding surfaces 11 and 21 from the plurality of through holes 17.

[0039] In addition, the storage space 16 has only the thickness of the front side wall portion 12 between the sliding surface 11 and the storage space 16, that is, the storage space 16 is disposed directly below the sliding surface 11. Therefore, the pressure loss and the like of the fluid F to be sealed supplied from the storage space 16 to the sliding surface 11 through the through hole 17 are small.

[0040] Further, the storage space 16 is defined by wall portions 12 to 15 having a rectangular frame shape in a radial cross-sectional view. Also, the storage space 16 is a cavity with a continuous radial cross-section. In other words, since the stationary seal ring 10 is cylindrical with a cavity formed continuously in the circumferential direction, the inside of the storage space 16 is less affected by the environment outside the stationary seal ring 10, such as the turbulent flow of the fluid F to be sealed outside the stationary seal ring 10, and it is easier to keep the pressure inside the storage space 16 substantially the same.

[0041] Also, the storage space 16 has a substantially the same radial flow path cross-sectional area and is continuous in the circumferential direction. Therefore, compared with a configuration in which the radial flow path cross-sectional area changes, it is easier to keep the pressure inside the storage space 16 substantially the same over the circumferential direction.

[0042] Also, only one pressure introduction portion 18 is formed. From this, compared with a configuration in which a plurality are formed, the influence due to the supply of the fluid F to be sealed into the storage space 16 can be reduced.

[0043] Also, the through-hole 17 extends linearly, and the pressure loss can be reduced compared with a configuration in which it extends in a polygonal line shape or a curved shape. Therefore, the fluid F to be sealed can be efficiently supplied from the storage space 16 between the sliding surfaces 11 and 21.

[0044] Also, the through-hole 17 is formed in a circular shape in a cross-sectional view. Therefore, the pressure loss can be reduced compared with a configuration in which it is formed in a polygonal shape in a cross-sectional view.

[0045] Also, the through-hole 17 has a substantially the same flow path cross-sectional area over the extending direction. Therefore, the pressure loss can be reduced compared with a configuration in which the flow path cross-sectional area changes.

[0046] Also, since the axial dimensions of each through-hole 17 are substantially the same, the pressure loss generated when the fluid F to be sealed passes through the through-hole 17 becomes substantially the same. As a result, it is easier to make the static pressure of the fluid F to be sealed flowing out from each through-hole 17 substantially the same.

[0047] Further, since the inner peripheral surface 17b of each through hole 17 extends in the axial direction orthogonal to the sliding surface 11, the pressure loss can be reduced as compared with a configuration in which the inner peripheral surface of the through hole extends inclined with respect to the sliding surface 11. Therefore, it is easy to make the pressure and flow rate of the fluid F to be sealed supplied through each through hole 17 substantially the same.

[0048] As a result, the pressure distribution in the circumferential direction between the sliding surfaces 11 and 21 becomes substantially uniform. Therefore, the relative rotation between the stationary seal ring 10 and the rotating seal ring 20 can be stabilized.

[0049] Further, the through hole 17 extends orthogonal to the sliding surface 11. Therefore, as compared with a configuration in which the through hole is inclined with respect to the sliding surface 11, it is easier to apply the static pressure in a direction substantially orthogonal to the sliding surface 21 of the rotating seal ring 20, that is, in substantially the same direction as the direction in which the sliding surfaces 11 and 21 are relatively separated from each other. Thereby, the static pressure of the fluid F to be sealed can be efficiently applied from the storage space 16 between the sliding surfaces 11 and 21.

[0050] Further, the through hole 17 is formed flush with the sliding surface 11 at the opening 17a. For example, since there is no 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 at high speed rotation, and it is easy to maintain the initial pressure between the sliding surfaces 11 and 21.

[0051] Further, the stationary seal ring 10 in which the storage space 16, the through hole 17, and the pressure introduction portion 18 are formed is provided in a stationary state without rotation. Since the stationary seal ring 10 does not rotate during start-up and relative rotation during normal operation, the flow of the fluid F to be sealed in the storage space 16 is unlikely to occur, and the fluid F to be sealed can be stably supplied from the storage space 16 to the through hole 17.

[0052] Further, each through-hole 17 is formed on the outer diameter side of the sliding surface 11. Compared with the configuration in which each through-hole 17 is formed on the inner diameter side of the sliding surface 11, the separation distance from each through-hole 17 to the atmosphere A side is long. Thereby, not only can leakage of the fluid F to be sealed be prevented, but also the region where the fluid F to be sealed can be supplied in the radial direction can be widened.

[0053] Also, since it is easy to change the arrangement and shape of the plurality of through-holes 17, it is easy to meet the requirements for the pressure and amount of the fluid supplied between the sliding surfaces 11 and 21.

[0054] Also, the through-holes 17 are arranged in a staggered pattern. From this, compared with the configuration in which the same number of through-holes of this embodiment are arranged on one circle along the circumferential direction, it is possible to arrange adjacent through-holes 17 close to each other. Thereby, many through-holes 17 can be arranged while maintaining the structural strength of the stationary seal ring 10. Also, since the through-holes 17 can be arranged densely, the pressure balance in the circumferential direction between the sliding surfaces 11 and 21 is good.

[0055] Also, each through-hole 17 is a through-hole formed in the front side wall portion 12. Therefore, the structure can be simplified compared with a configuration in which an orifice is separately attached to the stationary seal ring 10.

[0056] Also, the pressure introduction portion 18 is arranged to be located on the lower side in the vertical direction in the mechanical seal M (see FIG. 1). Therefore, even if dust or the like is mixed in the fluid F to be sealed, it is difficult to enter the storage space 16 through the pressure introduction portion 18. Also, even if the fluid F to be sealed in which dust or the like is mixed enters the storage space 16, it sinks due to gravity and is easily discharged from the pressure introduction portion 18. From this, clogging of the through-holes 17 can be prevented. In addition, the stationary seal ring 10 is provided in a stationary state without rotation. Therefore, the position of the pressure introduction portion 18 can be maintained.

[0057] In the present embodiment, the pressure introduction portion 18 has been described as being formed on the outer diameter side wall portion 13 of the stationary seal ring 10. However, the present invention is not limited to this. As in the case of the stationary seal ring 10A shown in FIG. 5, the pressure introduction portion 118 may be formed on the back side wall portion 14, and may be changed as appropriate.

[0058] In addition, a plurality of pressure introduction portions 18 or 118 may be formed in the stationary seal ring. For example, one or a plurality of pressure introduction portions 18 and 118 may be formed respectively.

[0059] In addition, the axial dimension of the through hole 17, in other words, the thickness dimension of the front side wall portion 12, may be changed as appropriate. Thereby, the static pressure of the sealed fluid F supplied between the sliding surfaces 11 and 21 can be adjusted by utilizing the pressure loss when the sealed fluid F passes through the through hole 17.

Embodiment

[0060] Next, a second embodiment of the sliding component will be described with reference to FIG. 6. Note that the description of the same configuration as that of the first embodiment will be omitted.

[0061] As shown in FIG. 6(a), a plurality of through holes 171, 172, 173, and 174 are formed in the stationary seal ring 110 from the outer diameter side toward the inner diameter side.

[0062] As shown in FIG. 6(b), the front side wall portion 120 has an inclined back surface 121, and its thickness dimension gradually increases from the outer diameter side toward the inner diameter side. Therefore, the axial dimension of the through holes 171 to 174 is the shortest for the through hole 171. Further, the through holes 172 and 173 are longer in this order, and the through hole 174 is the longest.

[0063] As a result, the through holes 171 to 174 are formed in a wider radial region in the stationary seal ring 110 compared to the stationary seal ring 10 of the first embodiment. Therefore, the sealed fluid F can be supplied more stably between the sliding surfaces 111 and 21.

[0064] Further, among the through holes 171 to 174, the ones closer to the inner diameter side have longer axial dimensions. From this, the pressure loss is greater for the ones closer to the inner diameter side. In other words, since the static pressure of the sealed fluid F supplied between the sliding surfaces 111 and 21 through the through holes closer to the inner diameter side is more reduced, the static pressure of the sealed fluid F between the sliding surfaces 111 and 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 the leakage amount and an improvement in lubricity.

Example

[0065] Next, Example 3 of the sliding component will be described with reference to FIG. 7. Note that descriptions of the same configurations as those in the above Examples 1 and 2 will be omitted.

[0066] As shown in FIG. 7, a plurality of spiral-shaped dynamic pressure generating grooves 19 are formed in the sliding surface 211 of the stationary seal ring 210. The dynamic pressure generating grooves 19 extend from the inner diameter side end of the stationary seal ring 210 toward the outer diameter side while curving along the rotation direction of the rotating seal ring 20. Also, the dynamic pressure generating grooves 19 are arranged at predetermined intervals across the circumferential direction of the sliding surface 211.

[0067] Referring to FIG. 7(a), in the dynamic pressure generating groove 19, at an acute-angled corner 19a located on the outer diameter side and on the rotation direction side of the rotating seal ring 20, the fluid flowing into the dynamic pressure generating groove 19 due to the rotation is concentrated, and dynamic pressure can be generated.

[0068] Thereby, at the time of low-speed rotation at the start of the rotating machine, the static pressure of the sealed fluid F supplied between the sliding surfaces 211 and 21 by the through hole 17 as in Example 1 mainly acts as a force to separate the sliding surfaces 11 and 21. On the other hand, at the time of high-speed rotation during normal operation, the dynamic pressure generated by the dynamic pressure generating groove 19 mainly acts as a force to slightly separate the sliding surfaces 11 and 21. In this way, the driving torque can be reduced from the start to normal operation.

Example

[0069] Next, Example 4 of the sliding component will be described with reference to FIGS. 8 to 10. Note that descriptions of configurations that are the same as those in the above Examples 1 to 3 will be omitted.

[0070] As shown in FIG. 8, the openings 17a, 217a (see FIGS. 9 and 10) of the through holes 17, 217 are staggeredly arranged on the sliding surface 311 of the stationary seal ring 310. The openings 17a, 217a are arranged in the circumferential direction on the outer diameter side in the radial direction of the sliding surface 311.

[0071] Referring to FIGS. 9 and 10, the openings 217c communicating with the storage space 16 of the through hole 217 are alternately arranged and formed on the same circle as the openings 17c communicating with the storage space 16 of the through hole 17. The through hole 217 extends linearly toward the sliding surface 311 while being inclined outward from the opening 217c. Further, the through hole 217 is continuous with the opening 217a on the sliding surface 311.

[0072] Thereby, the opening 217a of the through hole 217 can be arranged on the outer diameter side of the storage space 16, that is, on the side of the fluid F to be sealed. Therefore, compared with Example 1, the separation distance toward the atmosphere A side is long. Thus, not only can leakage of the fluid F to be sealed be prevented, but also the region where the fluid F to be sealed can be supplied in the radial direction can be widened.

[0073] Further, the through hole 217 is inclined and has an axial dimension longer than the axial dimension of the through hole 17, and has a larger pressure loss than the through hole 17. In addition, since a small static pressure is supplied to the sliding surface 311, it is less likely to leak to the side of the fluid F to be sealed.

[0074] Further, the opening 217a of the through hole 217 is formed flush with the sliding surface 311. Therefore, no dynamic pressure is generated during normal operation at high speed rotation, and it is easy to maintain the initial pressure between the sliding surfaces 311 and 21.

[0075] As described above, the embodiments of the present invention have been described with reference to the drawings. However, the specific configuration is not limited to these embodiments, and modifications and additions within the scope not departing from the gist of the present invention are also included in the present invention.

[0076] For example, in the above embodiment, the sliding component has been described as a configuration applied to a mechanical seal. However, the present invention is not limited thereto, and it may be applied to components other than mechanical seals, such as sliding bearings.

[0077] Also, although the mechanical seal has been described as an inside type, the present invention is not limited thereto, and it may be an outside type.

[0078] Also, although the fluid to be sealed has been described as a high-pressure liquid, the present invention is not limited thereto, and it may be in a mist state in which a liquid and a gas are mixed, a gas, or a low-pressure fluid.

[0079] Also, although the fluid on the leakage side has been described as air, the present invention is not limited thereto, and it may be a liquid, a mist state in which a liquid and a gas are mixed, or a fluid having a higher pressure than the fluid to be sealed.

[0080] Also, the sliding component in which the storage space and the through hole are formed has been described as a stationary seal ring. However, the present invention is not limited thereto, and it may be a rotating seal ring.

[0081] Also, although the storage space has been described as being defined by the respective wall portions arranged in four directions, the present invention is not limited thereto. As in the stationary seal ring 410 shown in FIG. 11, the back side between the outer diameter side wall portion 13 and the inner diameter side wall portion 15 is open, and the storage space 216 defined by the respective wall portions 12, 13, and 15 may be directly communicated with the back side of the stationary seal ring 310. In such a configuration, it is preferable to narrow the flow path communicating with the back side of the storage space 216 by using a housing, a case, or the like, so that the external fluid hardly affects the fluid in the storage space 216.

[0082] In addition, although the storage space has been described as being defined by each wall portion arranged in a rectangular frame shape in a cross-sectional view, it is not limited to this, and it may be a polygonal frame shape other than a rectangular frame, or it may be a D-shaped cross-sectional view in which a C-shaped wall portion is continuous with respect to the front side wall portion. As long as the wall portions are arranged in a cylindrical shape, the cross-sectional shape may be appropriately changed.

[0083] In addition, although the storage space has been described as having a rectangular cross-sectional shape, it is not limited to this, and it may be other polygonal shapes or circular shapes, and may be appropriately changed.

[0084] In addition, although the storage space has been described as being continuous in the circumferential direction, it is not limited to this, and it may be divided in the circumferential direction and a plurality of them may be formed. In this case, it is preferable that communication holes are formed to communicate the storage spaces adjacent to the dividing wall. In addition, the cross-sectional area of the flow path in the circumferential direction may change.

[0085] In addition, the stationary seal ring may be formed of a plurality of members. For example, like the stationary seal ring 510 shown in FIG. 12, it may be formed by fixing a separate lid member 114 to a base material having wall portions 12, 13, and 15.

[0086] In addition, although the through hole has been described as extending linearly, it is not limited to this. As long as it communicates with the sliding surface and the storage space respectively, it may be curved in a curved shape, may be bent at at least one place, and may be appropriately changed.

[0087] In addition, although the through holes have been described as being arranged in a staggered pattern, it is not limited to this, and they may be arranged in only one row, may be arranged in parallel in the same diameter direction, and may be appropriately changed.

[0088] In addition, although the through holes have been described as being arranged at predetermined intervals, it is not limited to this, and they may be arranged regularly or irregularly even if they are not at predetermined intervals.

[0089] In addition, although the through-hole has been described as having a circular cross-sectional shape, it is not limited to this, and it may be polygonal or star-shaped, and its shape may be changed as appropriate.

[0090] In addition, although the through-hole has been described as having a substantially identical flow path cross-sectional area, it is not limited to this, and it may vary.

[0091] In addition, although the fluid has been described as the fluid to be sealed, it is not limited to this, and it may be a fluid other than the fluid to be sealed supplied through the pressure introduction portion.

[0092] In addition, although the dynamic pressure generating groove has been described as having a spiral shape, it is not limited to this, and for example, it may be a Rayleigh step groove which is a positive dynamic pressure generating groove, an inverse Rayleigh groove which is a negative dynamic pressure generating groove, a herringbone groove, a rectangular groove, a dimple, etc., or a combination thereof, and it may be changed as appropriate.

Explanation of Reference Numerals

[0093] 10, 10A Stationary sealing ring (sliding part) 11 Sliding surface 16 Storage space (cavity) 17 Through-hole 17a Opening (opening on the sliding surface side) 18 Pressure introduction portion 19 Dynamic pressure generating groove 20 Rotating sealing ring (other sliding part) 21 Sliding surface 110~510 Stationary sealing ring (sliding part) 111~311 Sliding surface 118 Pressure introduction portion 171~174 Through-holes 216 Storage space 217 Through-hole A Atmosphere F Fluid to be sealed (fluid) M Mechanical seal

Claims

1. A sliding component that is disposed at a relatively rotating location of a rotary machine and slides relative to other sliding components, wherein the sliding component is provided with a storage space formed on the back side of the sliding surface of the sliding component into which a fluid is introduced, and a plurality of through holes that communicate between the storage space and the sliding surface. The storage space is an annular sliding component that is continuous in the circumferential direction of the sliding component.

2. A sliding component that is disposed at a relatively rotating location of a rotary machine and slides relative to other sliding components, wherein the sliding component is provided with a storage space formed on the back side of the sliding surface of the sliding component into which a fluid is introduced, and a plurality of through holes that communicate between the storage space and the sliding surface. The storage space is a sliding component that is a cavity in which the radial cross section of the sliding component is continuous in the circumferential direction.

3. The sliding component according to claim 1 or 2, wherein the through holes extend linearly.

4. The sliding component according to any one of claims 1 to 3, wherein the through holes extend perpendicular to the sliding surface.

5. The sliding component according to any one of claims 1 to 4, wherein the opening of the through hole on the sliding surface side is flush with the sliding surface.

6. The sliding component according to any one of claims 1 to 5, wherein a hydrodynamic groove is provided on the sliding surface.

7. The sliding component according to any one of claims 1 to 6, wherein the sliding component is a stationary sliding component.

8. The sliding component according to any one of claims 1 to 7, wherein the fluid is a fluid to be sealed.

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