Sliding member

Abstract

The present invention provides a sliding member capable of reliably introducing a fluid into a dynamic pressure generating groove. In a sliding member in which sliding surfaces (11, 21) of a pair of sliding rings (10, 20) rotate relative to each other and define an outer diameter space (S1) and an inner diameter space (S2), at least one of the sliding surfaces (11) is provided with: a dynamic pressure generating groove (12) extending in the circumferential direction; and a deep groove (14) extending in the circumferential direction, the circumferential end (14a) of the deep groove (14) on the downstream side of the relative rotation communicating with the upstream end (12b) of the relative rotation of the one of the dynamic pressure generating grooves (12).

Description

Technical Field

[0001] This invention relates to a sliding component, for example, a sliding component for a shaft seal or bearing. Background Technology

[0002] As a sliding component used in rotating machinery to prevent leakage of sealed fluid around a rotating shaft, mechanical seals are known, for example, consisting of a pair of annular sliding rings that rotate relative to each other and whose sliding surfaces slide against each other. In recent years, due to environmental countermeasures and other reasons, it has become desirable to reduce energy loss due to sliding, and mechanical seals with dynamic pressure generating grooves provided on the sliding surfaces of the sliding rings have emerged.

[0003] For example, in the mechanical seal shown in Patent Document 1, a sliding surface of one sliding ring has a circumferential groove, and a helical groove is formed on the inner diameter side of the circumferential groove. One end of the helical groove communicates with the circumferential groove. When a pair of sliding rings rotate relative to each other, fluid stored in the circumferential groove can be introduced into the helical groove, thereby generating dynamic pressure at the closed end of the helical groove. As a result, the sliding surfaces are slightly separated from each other, reducing the frictional force generated during relative sliding. Existing technical documents Patent documents

[0004] Patent Document 1: International Publication No. 2018 / 092742 (page 13, Figure 6 ) Summary of the Invention The problem that the invention aims to solve

[0005] In the mechanical seal of Patent Document 1, in the initial stage of the relative forward rotation of a pair of sliding rings, i.e., at low speed, the fluid stored in the circumferential groove can be introduced into the spiral groove, thereby reliably generating dynamic pressure. However, when the relative rotation speed of the pair of sliding rings increases, the fluid tends to flow along the circumferential groove in the circumferential direction, so the fluid may have difficulty flowing from the circumferential groove toward the spiral groove.

[0006] This invention was made in view of this problem, and its purpose is to provide a sliding component that can reliably introduce fluid into a hydrodynamic generating tank. Methods for solving problems

[0007] To address the aforementioned issues, the sliding component of the present invention is a sliding component in which the sliding surfaces of a pair of sliding rings rotate relative to each other, thereby dividing an outer diameter space and an inner diameter space. At least one of the sliding surfaces has: Dynamic pressure generating groove, extending circumferentially; and The deep groove extends circumferentially, with its circumferential end on the relatively rotating downstream side communicating with the relatively rotating upstream end of one of the dynamic pressure generating grooves. Therefore, the circumferential end of the deep groove restricts the circumferential movement of the fluid, and the fluid is reliably introduced into the dynamic pressure generating groove, thus enabling the effective generation of dynamic pressure in the dynamic pressure generating groove.

[0008] The dynamic pressure generating groove includes an inner diameter side dynamic pressure generating groove and an outer diameter side dynamic pressure generating groove disposed at a position closer to the outer diameter side than the inner diameter side dynamic pressure generating groove. The deep groove may include: an inner diameter side deep groove, disposed at a position closer to the outer diameter side than the inner diameter side dynamic pressure generating groove, having a circumferential end on the downstream side of relative rotation in the circumferential direction, and the circumferential end communicating with the upstream end of relative rotation of the inner diameter side dynamic pressure generating groove; and an outer diameter side deep groove, disposed at a position closer to the inner diameter side than the outer diameter side dynamic pressure generating groove, having a circumferential end on the downstream side of relative rotation in the circumferential direction, and the circumferential end communicating with the upstream end of relative rotation of the outer diameter side dynamic pressure generating groove. As a result, the fluid is introduced from the inner diameter side deep groove into the inner diameter side dynamic pressure generating groove, and the fluid is introduced from the outer diameter side deep groove into the outer diameter side dynamic pressure generating groove. Therefore, the fluid is difficult to leak from the inner diameter side deep groove and the outer diameter side deep groove into the sliding surface, and thus the fluids are difficult to mix.

[0009] The sidewalls of the deep groove and the upstream end of the hydrodynamic pressure generating groove can be directly connected radially from the circumferential end of the deep groove to the opposite rotational sidewall of the hydrodynamic pressure generating groove. This allows for a smooth and reliable supply of fluid from the deep tank to the hydrodynamic generating tank.

[0010] At least one of the relatively rotating downstream end of the inner diameter side dynamic pressure generating groove and the relatively rotating downstream end of the outer diameter side dynamic pressure generating groove can be tapered at the front end along the inner diameter direction or the outer diameter direction when viewed axially. As a result, fluid is discharged from the inner diameter side dynamic pressure generating groove to the inner diameter side, and fluid is discharged from the outer diameter side dynamic pressure generating groove to the outer diameter side, thus suppressing the mutual interference of dynamic pressure generated by the inner diameter side dynamic pressure generating groove and the outer diameter side dynamic pressure generating groove.

[0011] A pressure relief groove extending circumferentially can be provided between the inner diameter side deep groove and the outer diameter side deep groove. As a result, the fluid is recovered by the recovery tank, making it difficult for the fluids to mix, and suppressing the mutual interference of the dynamic pressure generated by the dynamic pressure generating tank on the inner diameter side and the dynamic pressure generating tank on the outer diameter side.

[0012] A storage trough extending circumferentially may be provided on the circumferentially extended portion of the deep groove. As a result, the fluids are recycled in the storage tank, making it difficult for the fluids to mix.

[0013] The downstream end of the relative rotation of the dynamic pressure generating groove can be configured between the deep grooves that are adjacent in the circumferential direction. Therefore, the downstream end of the relative rotation of the dynamic pressure generating groove is offset from the adjacent downstream deep groove in the circumferential direction, thus improving the dynamic pressure effect generated at the downstream end of the relative rotation.

[0014] It has a reverse dynamic pressure generating groove extending circumferentially opposite to the dynamic pressure generating groove. The deep groove may have a circumferential end that communicates with the upstream end of the reverse pressure generating groove in a relative rotation. Therefore, dynamic pressure is generated in the dynamic pressure generating tank during forward rotation, and fluid can be recovered in the reverse dynamic pressure generating tank. Similarly, dynamic pressure is generated in the reverse dynamic pressure generating tank during reverse rotation, and fluid can be recovered in the dynamic pressure generating tank.

[0015] A dynamic pressure generating element that communicates with the outer diameter space or the inner diameter space can be set. This improves the buoyancy between the sliding surfaces, thereby enhancing lubrication. Attached Figure Description

[0016] Figure 1 This is a longitudinal sectional view showing an example of the mechanical seal in Embodiment 1 of the present invention. Figure 2 This is a diagram showing the sliding surface of the stationary sealing ring in Example 1 as viewed from the axial direction. Figure 3 yes Figure 2 Enlarged view of the main parts. Figure 4 This is a diagram of the sliding surface of the stationary sealing ring viewed from the axial direction when the rotating sealing ring is rotating forward. Figure 5 This is a diagram of the sliding surface of the stationary sealing ring viewed from the axial direction when the rotating sealing ring rotates in the reverse direction. Figure 6 This is a diagram showing the sliding surface of the stationary sealing ring in Embodiment 2 of the present invention viewed from the axial direction. Figure 7 This is a diagram showing the sliding surface of the stationary sealing ring in Embodiment 3 of the present invention viewed from the axial direction. Figure 8 This is a diagram showing a modified example of the sliding surface of the stationary sealing ring in Embodiment 1 of the present invention. Detailed Implementation

[0017] The following describes the method of implementing the sliding component of the present invention based on embodiments. Example 1

[0018] Regarding the sliding component of Embodiment 1, refer to... Figures 1 to 5The following explanation will be provided. In this embodiment, a mechanical seal will be used as an example of a sliding component. In this embodiment, the mechanical seal contains a first fluid F1, such as oil, in the outer space S1, which is the outer diameter space, and a second fluid F2, such as water, in the inner space S2, which is the inner diameter space. Furthermore, for ease of explanation, grooves or other markings formed on the sliding surface are sometimes indicated in the accompanying drawings.

[0019] Figure 1 The mechanical seal shown is an inner-side type mechanical seal that seals against leakage of a first fluid F1 from the outer diameter side of the sliding surface toward the inner diameter side. Specifically, an example is given where the pressure of the first fluid F1 is higher than the pressure of the second fluid F2.

[0020] The mechanical seal mainly consists of a stationary sealing ring 10 and a rotating sealing ring 20. The stationary sealing ring 10 is annular and is mounted on a sealing cover 5 fixed to the housing 4 of the installed equipment in a non-rotating state and capable of axial movement. The rotating sealing ring 20 is annular and is mounted on the rotating shaft 1 via a sleeve 2, capable of rotating together with the rotating shaft 1. The stationary sealing ring 10 is subjected to axial force by an elastic member 7. The sliding surface 11 of the stationary sealing ring 10 and the sliding surface 21 of the rotating sealing ring 20 slide in close contact with each other. Furthermore, the sliding surface 21 of the rotating sealing ring 20 is a flat surface without grooves or other recesses.

[0021] The stationary sealing ring 10 and the rotary sealing 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 these. Any sliding material that can be used as a sliding material for mechanical seals can be applied. Furthermore, as SiC, there are materials composed of two or more phases with different compositions, such as sintered bodies using boron, aluminum, carbon, etc., as sintering aids. Examples include SiC with dispersed graphite particles, reaction-sintered SiC composed of SiC and Si, SiC-TiC, SiC-TiN, etc. As carbon, resin-molded carbon and sintered carbon, such as carbon mixed with carbonaceous and graphitic materials, can be used. In addition to the above-mentioned sliding materials, metallic materials, resin materials, surface-modified materials (coating materials), composite materials, etc., can also be used.

[0022] like Figure 2 As shown, the rotating sealing ring 20 slides counterclockwise relative to the stationary sealing ring 10 as indicated by the solid arrow, or clockwise relative to it as indicated by the dashed arrow. The direction of the solid arrow will be used as the forward rotation direction of the rotating sealing ring 20, and the direction of the dashed arrow will be used as the reverse rotation direction.

[0023] The sliding surface 11 of the stationary sealing ring 10 is provided with a dynamic pressure generating mechanism A, a dynamic pressure generating mechanism B, an annular groove 18, and a dynamic pressure generating element 19. The other planar portion is the platform surface L.

[0024] Multiple dynamic pressure generating mechanisms A and B are evenly distributed in the circumferential direction (4 of each in this embodiment).

[0025] The dynamic pressure generating mechanism A consists of an outer diameter side dynamic pressure generating groove 12, an outer diameter side reverse dynamic pressure generating groove 13, and an outer diameter side deep groove 14.

[0026] The dynamic pressure generating mechanism B consists of an inner diameter side dynamic pressure generating groove 15, an inner diameter side reverse dynamic pressure generating groove 16, and an inner diameter side deep groove 17.

[0027] The annular groove 18 is composed of an annular portion 18a disposed on the outer diameter side of the dynamic pressure generating mechanism A and a connecting portion 18b which communicates with the outer space S1 at multiple circumferential locations (four locations in this embodiment) of the annular portion 18a. The connecting portion 18b is circumferentially offset from the outer diameter side deep groove 14 and the inner diameter side deep groove 17.

[0028] Multiple (four in this embodiment) dynamic pressure generating elements 19 are formed in the region surrounded by the annular portion 18a and two adjacent connecting portions 18b. The dynamic pressure generating elements 19 are arranged at a position that overlaps radially with the outer diameter side deep groove 14 and the inner diameter side deep groove 17.

[0029] The dynamic pressure generating element 19 has a radial groove 19a communicating with the outer space S1, and Rayleigh steps 19b and 19c extending circumferentially from the inner diameter end of the radial groove 19a to both sides. Furthermore, the radial groove 19a is formed at the same depth as the Rayleigh steps 19b and 19c, but it may also be formed at a different depth.

[0030] First, the dynamic pressure generating mechanism A will be described in detail. For example... Figure 3 As shown, the outer diameter side deep groove 14 is generally arc-shaped and extends in a generally concentric circle with the sliding surface 11. The outer diameter side dynamic pressure generating groove 12 and the outer diameter side reverse dynamic pressure generating groove 13 are disposed at positions closer to the outer diameter side than the outer diameter side deep groove 14. Furthermore, the outer diameter side deep groove 14, the outer diameter side dynamic pressure generating groove 12, and the outer diameter side reverse dynamic pressure generating groove 13 are surrounded by the platform surface L and isolated from the outer space S1 and the inner space S2.

[0031] Specifically, the outer diameter side dynamic pressure generating groove 12 has a circumferential portion 12a, an inclined portion 12b, and an end portion 12c. The circumferential portion 12a is located on the outer diameter side closer to the outer diameter side than the outer diameter side deep groove 14, and extends in a generally concentric circle with the sliding surface 11.

[0032] End portion 12c is one end of the circumferential portion 12a, that is, the downstream end of the relative rotation during forward rotation, and tapers from the circumferential portion 12a toward the front end in the outer diameter direction when viewed axially. End portion 12c is positioned closer to the inner diameter side than the connecting portion 18b of the annular groove 18.

[0033] The inclined portion 12b is the other end of the circumferential portion 12a, that is, the upstream end of the relative rotation when rotating forward, and extends towards the inner diameter side while tilting from the circumferential portion 12a towards the upstream of the relative rotation.

[0034] The inclined portion 12b is connected to the outer diameter side of the outer diameter side deep groove 14. In other words, the inclined portion 12b of the outer diameter side dynamic pressure generating groove 12 overlaps with the outer diameter side deep groove 14 in the radial direction, that is, they coincide in the radial direction. The inner diameter side wall 12d of the inclined portion 12b is connected to the circumferential end 14a of one end side of the outer diameter side deep groove 14.

[0035] The outer diameter side reverse pressure generating groove 13 has a circumferential portion 13a, an inclined portion 13b, and an end portion 13c. The circumferential portion 13a is located on the outer diameter side closer to the outer diameter side than the outer diameter side deep groove 14, and extends in a generally concentric circle with the sliding surface 11.

[0036] End portion 13c is the other end of the circumferential portion 13a, that is, the upstream end of the relative rotation during forward rotation, and tapers from the circumferential portion 13a toward the front end in the outer diameter direction when viewed axially. End portion 13c is positioned closer to the inner diameter side than the connecting portion 18b of the annular groove 18.

[0037] The inclined portion 13b is one end of the circumferential portion 13a, that is, the downstream end of the relative rotation when rotating forward, and extends towards the inner diameter side while being inclined from the circumferential portion 13a towards the downstream of the relative rotation.

[0038] The inclined portion 13b is connected to the outer diameter side of the outer diameter side deep groove 14. In other words, the inclined portion 13b of the outer diameter side reverse pressure generating groove 13 overlaps with the outer diameter side deep groove 14 in the radial direction, that is, they coincide in the radial direction. The inner diameter side wall 13d of the inclined portion 13b is connected to the circumferential end 14b of the other end of the outer diameter side deep groove 14.

[0039] In addition, the inclined portion 12b of the outer diameter side dynamic pressure generating groove 12 and the inclined portion 13b of the outer diameter side reverse dynamic pressure generating groove 13 are connected in the circumferential direction.

[0040] Furthermore, the outer diameter side dynamic pressure generating groove 12 and the outer diameter side reverse dynamic pressure generating groove 13 are formed to the same depth, and are formed to be shallower than the outer diameter side deep groove 14.

[0041] The dynamic pressure generating mechanism A is symmetrical in shape with reference to an imaginary line α that passes through the circumferential center of the outer diameter side deep groove 14 and extends radially.

[0042] Next, the dynamic pressure generating mechanism B will be described. The inner diameter side deep groove 17 is generally arc-shaped and extends in a generally concentric circle with the sliding surface 11. The inner diameter side dynamic pressure generating groove 15 and the inner diameter side reverse dynamic pressure generating groove 16 are disposed at positions closer to the inner diameter side than the inner diameter side deep groove 17. In other words, the inner diameter side dynamic pressure generating groove 15 and the inner diameter side reverse dynamic pressure generating groove 16 do not overlap with the outer diameter side dynamic pressure generating groove 12 and the outer diameter side reverse dynamic pressure generating groove 13 in the circumferential direction. Furthermore, the inner diameter side deep groove 17, the inner diameter side dynamic pressure generating groove 15, and the inner diameter side reverse dynamic pressure generating groove 16 are surrounded by the platform surface L and isolated from the outer space S1 and the inner space S2.

[0043] Specifically, the inner diameter side dynamic pressure generating groove 15 has a circumferential portion 15a, an inclined portion 15b, and an end portion 15c. The circumferential portion 15a is positioned closer to the inner diameter side than the inner diameter side deep groove 17 and extends in a generally concentric circle with the sliding surface 11.

[0044] End portion 15c is one end of the circumferential portion 15a, that is, the downstream end of the relative rotation during forward rotation, and tapers from the circumferential portion 15a toward the front end in the inner diameter direction when viewed axially. End portion 15c overlaps radially with the connecting portion 18b of the annular groove 18.

[0045] The inclined portion 15b is the other end of the circumferential portion 15a, that is, the upstream end of the relative rotation when rotating forward, and extends towards the outer diameter side while tilting from the circumferential portion 15a towards the upstream of the relative rotation.

[0046] The inclined portion 15b is connected to the inner diameter side of the inner diameter side deep groove 17. In other words, the inclined portion 15b of the inner diameter side dynamic pressure generating groove 15 overlaps with the inner diameter side deep groove 17 in the radial direction, that is, they coincide in the radial direction. The outer diameter side wall 15d of the inclined portion 15b is connected to the circumferential end 17a of one end side of the inner diameter side deep groove 17.

[0047] The inner diameter side reverse pressure generating groove 16 has a circumferential portion 16a, an inclined portion 16b, and an end portion 16c. The circumferential portion 16a is disposed at a position closer to the inner diameter side than the inner diameter side deep groove 17, and extends in a generally concentric circle with the sliding surface 11.

[0048] End 16c is the other end of the circumferential portion 16a, that is, the upstream end of the relative rotation when rotating forward, and tapers from the circumferential portion 16a toward the front end in the inner diameter direction when viewed axially. End 16c overlaps radially with the connecting portion 18b of the annular groove 18.

[0049] The inclined portion 16b is one end of the circumferential portion 16a, that is, the downstream end of the relative rotation when rotating forward, and extends towards the outer diameter side while being inclined from the circumferential portion 16a towards the downstream of the relative rotation.

[0050] The inclined portion 16b is connected to the inner diameter side of the inner diameter side deep groove 17. In other words, the inclined portion 16b of the inner diameter side reverse pressure generating groove 16 overlaps with the inner diameter side deep groove 17 in the radial direction, i.e., they coincide in the radial direction. The outer diameter side wall 16d of the inclined portion 16b is connected to the circumferential end 17b of the other end of the inner diameter side deep groove 17.

[0051] In addition, the inclined portion 15b of the inner diameter side dynamic pressure generating groove 15 is connected to the inclined portion 16b of the inner diameter side reverse dynamic pressure generating groove 16 in the circumferential direction.

[0052] Furthermore, the inner diameter side dynamic pressure generating groove 15 and the inner diameter side reverse dynamic pressure generating groove 16 are formed to the same depth, and are formed to be shallower than the outer diameter side deep groove 14.

[0053] The dynamic pressure generating mechanism B is symmetrical in shape with reference to an imaginary line α that passes through the circumferential center of the inner diameter side deep groove 17 and extends radially.

[0054] Next, refer to Figure 4 and Figure 5 The flow of the first fluid F1 and the second fluid F2 when the stationary sealing ring 10 and the rotating sealing ring 20 rotate relative to each other is briefly described. Furthermore, the relative rotational speeds of the stationary sealing ring 10 and the rotating sealing ring 20 are not specifically described here.

[0055] First, when the rotating sealing ring 20 stops rotating, the first fluid F1 flows into the dynamic pressure generating mechanism A, the annular groove 18, and the dynamic pressure generating element 19 near the outer space S1, and the second fluid F2 flows into the dynamic pressure generating mechanism B near the inner space S2.

[0056] Furthermore, since the sliding surfaces 11 and 21 are in contact with each other, the first fluid F1 and the second fluid F2 hardly mix between the sliding surfaces 11 and 21.

[0057] Next, the state in which the rotating sealing ring 20 rotates relative to the stationary sealing ring 10 in the positive direction will be described.

[0058] like Figure 4 As shown, when the rotating sealing ring 20 rotates relative to the stationary sealing ring 10 in the positive direction, the first fluid F1 and the second fluid F2 move in their respective grooves following the rotation direction of the stationary sealing ring 10.

[0059] Specifically, in the dynamic pressure generating element 19, the first fluid F1 moves toward the closed end 19d of the Rayleigh step 19b, generating positive pressure in and around the closed end 19d. Due to the force caused by the positive pressure generated in and around the closed end 19d of the Rayleigh step 19b, the sliding surfaces 11 and 21 separate from each other, thereby improving lubricity and suppressing wear between the sliding surfaces 11 and 21.

[0060] Furthermore, in the Rayleigh step 19c on the opposite side, the first fluid F1 moves from the closed end 19e to the radial groove 19a, thereby generating a relative negative pressure in and around the closed end 19e. Therefore, due to the relative negative pressure generated in and around the closed end 19e of the Rayleigh step 19c, the surrounding first fluid F1 is drawn in. It should be noted that this relative negative pressure is not a vacuum, but rather refers to a pressure lower than the surrounding pressure.

[0061] The first fluid F1 flowing out from the closed end 19d of Rayleigh step 19b into the space between sliding surfaces 11 and 21 is collected by the annular groove 18 and returned to the outer space S1.

[0062] In the dynamic pressure generating mechanism A, positive pressure is generated at and near the end 12c of the dynamic pressure generating groove 12 on the outer diameter side, and a relative negative pressure is generated at and near the end 13c of the reverse dynamic pressure generating groove 13 on the outer diameter side.

[0063] In detail, the first fluid F1 is supplied to the outer diameter side dynamic pressure generating groove 12 through the outer diameter side deep groove 14 and the communication portion with the outer diameter side reverse dynamic pressure generating groove 13. The first fluid F1 flowing in the outer diameter side deep groove 14 is restricted from moving to the relatively rotating downstream side by the circumferential end 14a of the outer diameter side deep groove 14, and is guided to the inclined portion 12b side of the outer diameter side dynamic pressure generating groove 12 that is connected in the radial direction. Thus, the first fluid F1 is reliably introduced into the outer diameter side dynamic pressure generating groove 12, and thus dynamic pressure can be effectively generated at and near the end 12c of the outer diameter side dynamic pressure generating groove 12.

[0064] In addition, since a large amount of first fluid F1 is stored in the outer diameter side deep groove 14, a sufficient amount of first fluid F1 can be supplied to the outer diameter side dynamic pressure generating groove 12 from the relative rotation low speed to the relative rotation high speed, thereby preventing insufficient lubrication.

[0065] Furthermore, since a relative negative pressure is generated at and near the end 13c of the reverse dynamic pressure generating groove 13 on the outer diameter side, the first fluid F1 at and near the end 13c can be recovered. The recovered first fluid F1 is supplied to the deep groove 14 on the outer diameter side or the dynamic pressure generating groove 12 on the outer diameter side.

[0066] In the dynamic pressure generating mechanism B, positive pressure is generated at and near the end 15c of the inner diameter side dynamic pressure generating groove 15, and a relative negative pressure is generated at and near the end 16c of the inner diameter side reverse dynamic pressure generating groove 16.

[0067] In detail, the second fluid F2 is supplied to the inner diameter side dynamic pressure generating groove 15 through the inner diameter side deep groove 17 and the communication portion with the inner diameter side reverse dynamic pressure generating groove 16. The second fluid F2 flowing in the inner diameter side deep groove 17 is restricted from moving to the relatively rotating downstream side by the circumferential end 17a of the inner diameter side deep groove 17, and is guided to the inclined portion 15b side of the inner diameter side dynamic pressure generating groove 15, which is connected in the radial direction. Thus, the second fluid F2 is reliably introduced into the inner diameter side dynamic pressure generating groove 15, and therefore, dynamic pressure can be effectively generated at and near the end 15c of the inner diameter side dynamic pressure generating groove 15.

[0068] In addition, since a large amount of second fluid F2 is stored in the inner diameter side deep groove 17, a sufficient amount of second fluid F2 can be supplied to the inner diameter side dynamic pressure generating groove 15 from the relative rotation low speed to the relative rotation high speed, thereby preventing insufficient lubrication.

[0069] Furthermore, since a relative negative pressure is generated at and near the end 16c of the reverse dynamic pressure generating groove 16 on the inner diameter side, the second fluid F2 at and near the end 16c can be recovered. The recovered second fluid F2 is supplied to the inner diameter side deep groove 17 or the inner diameter side dynamic pressure generating groove 15.

[0070] Next, the state in which the rotating sealing ring 20 rotates relative to the stationary sealing ring 10 in the opposite direction will be described.

[0071] like Figure 5 As shown, when the rotating sealing ring 20 rotates relative to the stationary sealing ring 10 in the opposite direction, the first fluid F1 and the second fluid F2 move in their respective grooves following the rotation direction of the stationary sealing ring 10.

[0072] Specifically, in the dynamic pressure generating element 19, a positive pressure is generated at and near the closed end 19e of the Rayleigh step 19c, and a relative negative pressure is generated at and near the closed end 19d of the Rayleigh step 19b on the opposite side.

[0073] Due to the positive pressure generated at and near the closed end 19e, the sliding surfaces 11 and 21 are separated from each other, thereby improving lubricity and suppressing wear between the sliding surfaces 11 and 21. In addition, due to the relative negative pressure generated at and near the closed end 19d, the surrounding first fluid F1 is drawn in.

[0074] The first fluid F1 flowing from the closed end 19d of Rayleigh step 19b and its vicinity into the sliding surfaces 11 and 21 is collected by the annular groove 18 and returned to the outer space S1.

[0075] In the dynamic pressure generating mechanism A, positive pressure is generated at and near the end 13c of the dynamic pressure generating groove 13 on the outer diameter side, and a relative negative pressure is generated at and near the end 12c of the dynamic pressure generating groove 12 on the outer diameter side.

[0076] The first fluid F1 flowing in the outer diameter side deep groove 14 is restricted from moving downstream of the relative rotation by the circumferential end 14b of the outer diameter side deep groove 14 and is guided to the inclined portion 13b side of the outer diameter side reverse dynamic pressure generating groove 13, which is radially connected. Thus, the first fluid F1 is reliably introduced into the outer diameter side reverse dynamic pressure generating groove 13, and dynamic pressure can be effectively generated at and near the end 13c of the outer diameter side reverse dynamic pressure generating groove 13.

[0077] In addition, since a large amount of first fluid F1 is stored in the deep groove 14 on the outer diameter side, a sufficient amount of first fluid F1 can be supplied to the reverse pressure generating groove 13 on the outer diameter side from the low relative rotation speed to the high relative rotation speed, thereby preventing insufficient lubrication.

[0078] Furthermore, since a relative negative pressure is generated at and near the end 12c of the outer diameter side dynamic pressure generating groove 12, the first fluid F1 at and near the end 12c can be recovered. The recovered first fluid F1 is supplied to the outer diameter side deep groove 14 or the outer diameter side reverse dynamic pressure generating groove 13.

[0079] In the dynamic pressure generating mechanism B, positive pressure is generated at and near the end 16c of the reverse dynamic pressure generating groove 16 on the inner diameter side, and a relative negative pressure is generated at and near the end 15c of the dynamic pressure generating groove 15 on the inner diameter side.

[0080] The second fluid F2 flowing in the inner diameter side deep groove 17 is restricted from moving downstream of the relative rotation by the circumferential end 17b of the inner diameter side deep groove 17, and is guided to the inclined portion 16b side of the inner diameter side reverse dynamic pressure generating groove 16, which is radially connected. Thus, the second fluid F2 is reliably introduced into the inner diameter side reverse dynamic pressure generating groove 16, and dynamic pressure can be effectively generated at and near the end 16c of the inner diameter side reverse dynamic pressure generating groove 16.

[0081] In addition, since a large amount of second fluid F2 is stored in the inner diameter side deep groove 17, a sufficient amount of second fluid F2 can be supplied to the inner diameter side reverse pressure generating groove 16 from the relative rotation low speed to the relative rotation high speed, thereby preventing insufficient lubrication.

[0082] Furthermore, since a relative negative pressure is generated at and near the end 15c of the inner diameter side dynamic pressure generating groove 15, the second fluid F2 at and near the end 15c can be recovered. The recovered second fluid F2 is supplied to the inner diameter side deep groove 17 or the inner diameter side reverse dynamic pressure generating groove 16.

[0083] As explained above, during forward rotation, the circumferential end 14a of the outer diameter side deep groove 14 restricts the movement of the first fluid F1 downstream of the relative rotation. Thus, the first fluid F1 is reliably introduced into the outer diameter side dynamic pressure generating groove 12, which has an inner diameter side wall 12d connected to the circumferential end 14a of the outer diameter side deep groove 14, thereby effectively generating dynamic pressure at the end 12c of the outer diameter side dynamic pressure generating groove 12.

[0084] Furthermore, the sliding surface 11 has a dynamic pressure generating mechanism A on the outer diameter side and a dynamic pressure generating mechanism B on the inner diameter side. As a result, the first fluid F1 is introduced into the outer diameter side dynamic pressure generating groove 12 from the outer diameter side deep groove 14, and the second fluid F2 is introduced into the inner diameter side dynamic pressure generating groove 15 from the inner diameter side deep groove 17. Therefore, the first fluid F1 and the second fluid F2 are unlikely to leak from the outer diameter side deep groove 14 and the inner diameter side deep groove 17 into the sliding surfaces 11 and 21, thus making it difficult for the fluids to mix.

[0085] Furthermore, the outer diameter side dynamic pressure generating groove 12 is positioned closer to the outer diameter side than the outer diameter side deep groove 14, and the inner diameter side dynamic pressure generating groove 15 is positioned closer to the inner diameter side than the inner diameter side deep groove 17. Fluid flowing from the outer diameter side dynamic pressure generating groove 12 into the sliding surfaces 11 and 21 is collected in the outer diameter side deep groove 14, and fluid flowing from the inner diameter side dynamic pressure generating groove 15 into the sliding surfaces 11 and 21 is collected in the inner diameter side deep groove 17, thus making it difficult for the fluids to mix.

[0086] Furthermore, since the outer diameter side deep groove 14 and the inner diameter side deep groove 17 can be made close in the radial direction, lubricity can be improved over a wide range in the radial direction.

[0087] Furthermore, the end 12c of the outer diameter side dynamic pressure generating groove 12 tapers towards the front end along the outer diameter direction when viewed axially, and the end 15c of the inner diameter side dynamic pressure generating groove 15 tapers towards the front end along the inner diameter direction when viewed axially. As a result, each fluid is discharged radially away from the end 12c of the outer diameter side dynamic pressure generating groove 12 and the end 15c of the inner diameter side dynamic pressure generating groove 15, thus making it difficult for the fluids to mix and suppressing the mutual interference of the dynamic pressure generated in the outer diameter side dynamic pressure generating groove 12 and the inner diameter side dynamic pressure generating groove 15.

[0088] In addition, an outer diameter-side dynamic pressure generating groove 12 is connected to an outer diameter-side deep groove 14, and an inner diameter-side dynamic pressure generating groove 15 is connected to an inner diameter-side deep groove 17. Thus, compared with the method of multiple dynamic pressure generating grooves connected to a single deep groove, the fluid is concentrated and introduced into the outer diameter-side dynamic pressure generating groove 12 and the inner diameter-side dynamic pressure generating groove 15, resulting in a higher dynamic pressure effect.

[0089] In addition, the end 12c of the outer diameter side dynamic pressure generating groove 12 and the end 15c of the inner diameter side dynamic pressure generating groove 15 are staggered from the outer diameter side deep groove 14 and the inner diameter side deep groove 17 in the circumferential direction. No grooves are formed around the ends 12c and 15c, so the dynamic pressure effect generated at the ends 12c and 15c can be improved.

[0090] Furthermore, an outer diameter-side reverse dynamic pressure generating groove 13 extends circumferentially to the opposite side of the outer diameter-side dynamic pressure generating groove 12. During reverse rotation, the first fluid F1 is guided to the outer diameter-side reverse dynamic pressure generating groove 13 by the circumferential end 14b of the outer diameter-side deep groove 14. During forward rotation, dynamic pressure is generated in the outer diameter-side dynamic pressure generating groove 12, enabling the recovery of the first fluid F1 in the outer diameter-side reverse dynamic pressure generating groove 13. Similarly, during reverse rotation, dynamic pressure is generated in the outer diameter-side reverse dynamic pressure generating groove 13, enabling the recovery of the first fluid F1 in the outer diameter-side dynamic pressure generating groove 12.

[0091] In addition, since it has a dynamic pressure generating element 19 that communicates with the outer space S1, the levitation effect between the sliding surfaces 11 and 21 can be improved, thereby improving lubricity.

[0092] Furthermore, the inner diameter side dynamic pressure generating groove 15 and the inner diameter side reverse dynamic pressure generating groove 16 do not overlap with the outer diameter side dynamic pressure generating groove 12 and the outer diameter side reverse dynamic pressure generating groove 13 in the circumferential direction. In other words, the inner diameter side dynamic pressure generating groove 15 and the inner diameter side reverse dynamic pressure generating groove 16 are radially separated from the outer diameter side dynamic pressure generating groove 12 and the outer diameter side reverse dynamic pressure generating groove 13, making it difficult for the fluids to mix.

[0093] Furthermore, in this embodiment, the inner diameter sidewall of the inclined portion 12b is connected to the circumferential end 14a of the outer diameter side deep groove 14, and the outer diameter sidewall of the inclined portion 15b is connected to the circumferential end 17a of the inner diameter side deep groove 17. However, the circumferential end of the deep groove can also be positioned relative to the relative rotation downstream or relative rotation upstream end of the dynamic pressure generating groove. Even in this case, the circumferential movement of the fluid is restricted by the circumferential end of the deep groove, thereby reliably guiding the fluid into the dynamic pressure generating groove.

[0094] In addition, the outer diameter side deep groove 14 and the inner diameter side deep groove 17 are not limited to arc shape, but can also extend in other curved shapes such as straight lines and wavy shapes.

[0095] In addition, the outer diameter side deep groove and the inner diameter side deep groove can be formed longer in the circumferential direction than in this embodiment. However, preferably, the outer diameter side deep groove and the inner diameter side deep groove are shorter than the outer diameter side dynamic pressure generating groove and the inner diameter side dynamic pressure generating groove, so that the oppositely rotating downstream ends of the outer diameter side deep groove and the inner diameter side deep groove and the outer diameter side dynamic pressure generating groove and the inner diameter side dynamic pressure generating groove do not overlap radially. Example 2

[0096] Next, refer to Figure 6 The sliding component of Embodiment 2 will be described. Furthermore, descriptions of structures identical or repetitive to those in Embodiment 1 will be omitted.

[0097] like Figure 6 As shown, in this embodiment 2, the sliding surface 211 of the stationary sealing ring 210 has multiple recovery grooves 30 serving as pressure relief grooves arranged circumferentially between the radially separated dynamic pressure generating mechanisms A and B. The recovery grooves 30 are approximately arc-shaped extending circumferentially and are deeper than the dynamic pressure generating grooves of each of the dynamic pressure generating mechanisms A and B. These recovery grooves 30 are circumferentially separated and arranged on approximately the entire circumference of the sliding surface 211.

[0098] Furthermore, on the approximately concentric circles of the outer diameter side deep groove 14 and the inner diameter side deep groove 17, a plurality of arc-shaped grooves 40 serving as inner diameter side storage grooves and arc-shaped grooves 50 serving as outer diameter side storage grooves are arranged separately in the circumferential direction. The arc-shaped grooves 40 and 50 have a shape that is approximately the same as that of the recovery groove 30. In addition, the arc-shaped grooves 40 and 50 are arranged circumferentially offset from the recovery groove 30.

[0099] The arc-shaped grooves 40 and 50 are not provided around the ends 12c and 13c of the dynamic pressure generating mechanism A and the ends 15c and 16c of the dynamic pressure generating mechanism B.

[0100] As a result, the fluid is recovered by the recovery tank 30 and the arc-shaped tanks 40 and 50, so the fluids are difficult to mix and the mutual interference of the dynamic pressure generated by the dynamic pressure generating mechanisms A and B can be suppressed.

[0101] In addition, the arc-shaped grooves 40 and 50 are not provided around the ends 12c and 13c of the dynamic pressure generating mechanism A and the ends 15c and 16c of the dynamic pressure generating mechanism B, so the arc-shaped grooves 40 and 50 will not affect the dynamic pressure effect.

[0102] Furthermore, in this embodiment 2, the recycling tank 30 is shown in a dashed ring shape when viewed axially from the sliding surface 211, but it can also be in a ring shape connected in the circumferential direction.

[0103] In addition, the arc-shaped grooves 40 and 50 are not necessary structures and can be omitted.

[0104] In addition, the arc-shaped grooves 40 and 50 can be configured to appear as dashed rings when viewed from the axial direction. Example 3

[0105] Next, refer to Figure 7 The sliding component of Embodiment 3 will be described. Furthermore, descriptions of structures identical or repetitive to those in Embodiment 2 will be omitted.

[0106] like Figure 7As shown, in this embodiment 3, two arc-shaped grooves 40' are provided on each side of the outer diameter side deep groove 14 in a circumferentially separated manner. The arc-shaped grooves 40', 40' on the side away from the outer diameter side deep groove 14 in the circumferential direction are positioned closer to the outer diameter side deep groove 14 than the imaginary line β. The imaginary line β passes through the middle position between the ends 14a, 14b of the outer diameter side deep groove 14 and the ends 12c, 13c of the dynamic pressure generating mechanism A and extends radially.

[0107] In this embodiment 3, two arc-shaped grooves 50' are provided on each side of the inner diameter side deep groove 17 in a circumferentially separated manner. The arc-shaped grooves 50' and 50' on the side of the inner diameter side deep groove 17 that are circumferentially away from it are positioned closer to the inner diameter side deep groove 17 than the imaginary line β.

[0108] Therefore, a sufficiently large platform area can be formed around the ends 12c and 13c of the dynamic pressure generating mechanism A and the ends 15c and 16c of the dynamic pressure generating mechanism B, thus further improving the dynamic pressure effect compared with the method of Embodiment 2.

[0109] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the specific structure is not limited to these embodiments, and any changes or additions that do not depart from the spirit of the present invention are also included in the present invention.

[0110] For example, in embodiments 1 to 3, a method of setting up a dynamic pressure generating mechanism A on the outer diameter side and a dynamic pressure generating mechanism B on the inner diameter side is illustrated, but it is sufficient to set up only one dynamic pressure generating mechanism.

[0111] In addition, in the embodiments 1 to 3, it is illustrated that multiple dynamic pressure generating mechanisms A on the outer diameter side and multiple dynamic pressure generating mechanisms B on the inner diameter side are respectively provided in the circumferential direction. However, it is sufficient to provide at least one dynamic pressure generating mechanism in the circumferential direction, and there is no need to provide multiple dynamic pressure generating mechanisms.

[0112] In addition, the dynamic pressure generating mechanism A and the dynamic pressure generating mechanism B on the inner diameter side are not limited to being arranged to overlap in the radial direction, but can also be arranged to be staggered in the circumferential direction.

[0113] Furthermore, in embodiments 1 to 3, the outer diameter-side dynamic pressure generating groove 12 and the outer diameter-side reverse dynamic pressure generating groove 13 are shown to be positioned closer to the outer diameter than the outer diameter-side deep groove 14, and the inner diameter-side dynamic pressure generating groove 15 and the inner diameter-side reverse dynamic pressure generating groove 16 are positioned closer to the inner diameter than the inner diameter-side deep groove 17. However, these configurations can be freely changed. For example, the outer diameter-side dynamic pressure generating groove and the outer diameter-side reverse dynamic pressure generating groove can be positioned closer to the inner diameter than the outer diameter-side deep groove, and the inner diameter-side dynamic pressure generating groove and the inner diameter-side reverse dynamic pressure generating groove can be positioned closer to the outer diameter than the inner diameter-side deep groove.

[0114] In addition, in the embodiments 1 to 3, a method in which a dynamic pressure generating groove is connected to a deep groove is illustrated, but it is also possible for multiple deep grooves to be connected to a dynamic pressure generating groove.

[0115] Furthermore, the dynamic pressure generating groove is not limited to being connected to the deep groove; the upstream end of the dynamic pressure generating groove, which rotates relative to the deep groove, can also be configured in a non-connected state near the circumferential end of the deep groove. Moreover, the upstream end of the dynamic pressure generating groove, which rotates relative to the deep groove, preferably overlaps with the deep groove in the radial direction.

[0116] In addition, in the embodiments 1 to 3, a method is illustrated in which the relatively rotating downstream end of the dynamic pressure generating groove is arranged between each other in the circumferential direction of the deep grooves. However, the deep groove of the dynamic pressure generating mechanism may also overlap radially with the relatively rotating downstream end of the dynamic pressure generating groove that is upstream of the dynamic pressure generating mechanism.

[0117] Furthermore, the outer diameter side dynamic pressure generating groove, the outer diameter side reverse dynamic pressure generating groove, the inner diameter side dynamic pressure generating groove, and the inner diameter side reverse dynamic pressure generating groove are not limited to the shapes described in embodiments 1 to 3, and can also be Rayleigh steps, spiral grooves, etc., and can be freely changed. In addition, the shape of its terminal part can also be freely changed.

[0118] Furthermore, in embodiments 1 to 3, a method is illustrated where a dynamic pressure generating element is provided on the outer diameter side. However, the structure of the dynamic pressure generating element may be omitted, and the dynamic pressure generating element may be provided on the inner diameter side or both radial sides. In addition, the number of dynamic pressure generating elements can be freely varied.

[0119] Furthermore, in embodiments 1 to 3, the outer diameter side dynamic pressure generating mechanism and the inner diameter side dynamic pressure generating mechanism are shown to correspond to each other in a dual-rotation manner, but they may also correspond to only a single rotation.

[0120] For example, it could also be Figure 8 The single rotation method is shown. A dynamic pressure generating mechanism 100A and a dynamic pressure generating mechanism 100B are provided on the sliding surface 111 of the stationary sealing ring 110.

[0121] The dynamic pressure generating mechanism 100A consists of an outer diameter-side dynamic pressure generating groove 112 and an outer diameter-side deep groove 114. The outer diameter-side dynamic pressure generating groove 112 communicates with the outer diameter side of the circumferential end 114a on the relatively rotating downstream side of the outer diameter-side deep groove 114 and extends towards the relatively rotating downstream side. Furthermore, the circumferential end 114b on the relatively rotating upstream side of the outer diameter-side deep groove 114 is surrounded by a platform surface L and isolated from the outer space S1, the inner space S2, and other grooves.

[0122] The dynamic pressure generating mechanism 100B consists of an inner diameter-side dynamic pressure generating groove 115 and an inner diameter-side deep groove 117. The inner diameter-side dynamic pressure generating groove 115 communicates with the inner diameter side of the circumferential end 117a on the relatively rotating downstream side of the inner diameter-side deep groove 117 and extends towards the relatively rotating downstream side. Furthermore, the circumferential end 117b on the relatively rotating upstream side of the inner diameter-side deep groove 117 is surrounded by a platform surface L and isolated from the outer space S1, the inner space S2, and other grooves.

[0123] In addition, in embodiments 2 and 3, a method in which a pressure relief groove or the like is not formed near the end of the dynamic pressure generating groove is illustrated, but a pressure relief groove or the like can also be formed near the end of the dynamic pressure generating groove.

[0124] Furthermore, in embodiments 1 to 3, a mechanical seal was used as an example of a sliding component, but other mechanical seals used in general industrial machinery, automobiles, water pumps, etc., can also be used. Additionally, it is not limited to mechanical seals; it can also be a sliding component other than a mechanical seal, such as a sliding bearing. Explanation of reference numerals in the attached figures

[0125] 1: Rotating shaft; 4: Housing; 10: Stationary sealing ring; 11: Sliding surface; 12: Outer diameter side dynamic pressure generating groove; 12c: End; 13: Outer diameter side reverse dynamic pressure generating groove; 13c: End; 14: Outer diameter side deep groove; 14a, 14b: Circumferential end; 15: Inner diameter side dynamic pressure generating groove; 15c: End; 16: Inner diameter side reverse dynamic pressure generating groove; 16c: End; 17: Inner diameter side deep groove; 17a, 17b: Circumferential end; 19: Dynamic pressure generating element; 20: Rotary sealing ring; 21: Sliding surface; 30: Recovery groove (pressure relief groove); 40: Outer diameter side arc-shaped groove (storage groove); 50: Inner diameter side arc-shaped groove (storage groove); 124a: Radial groove; A, B: Dynamic pressure generating mechanism; F1: First fluid; F2: Second fluid; S1: Outer space (outer diameter space); S2: Inner space (inner diameter space).

Claims

1. A sliding component, wherein the sliding surfaces of a pair of sliding rings of the sliding component rotate relative to each other and divide an outer diameter space and an inner diameter space, characterized in that, At least one of the sliding surfaces has: Dynamic pressure generating groove, extending circumferentially; and The deep groove extends circumferentially, with its circumferential end on the relatively rotating downstream side communicating with the relatively rotating upstream end of one of the dynamic pressure generating grooves.

2. The sliding component according to claim 1, characterized in that, The dynamic pressure generating groove includes an inner diameter side dynamic pressure generating groove and an outer diameter side dynamic pressure generating groove disposed at a position closer to the outer diameter side than the inner diameter side dynamic pressure generating groove. The deep groove has the following features: An inner diameter-side deep groove, positioned closer to the outer diameter side than the inner diameter-side dynamic pressure generating groove, has a circumferential end on the downstream side of relative rotation, and this circumferential end communicates with the upstream end of the inner diameter-side dynamic pressure generating groove in relative rotation; and The outer diameter side deep groove is positioned closer to the inner diameter side than the outer diameter side dynamic pressure generating groove, and has a circumferential end on the downstream side of relative rotation in the circumferential direction, and the circumferential end is connected to the upstream end of the outer diameter side dynamic pressure generating groove in relative rotation.

3. The sliding component according to claim 1, characterized in that, The sidewalls of the deep groove are directly connected radially from the circumferential end to the upstream end of the hydrodynamic pressure generating groove.

4. The sliding component according to claim 2, characterized in that, At least one of the relatively rotating downstream end of the inner diameter side dynamic pressure generating groove and the relatively rotating downstream end of the outer diameter side dynamic pressure generating groove tapers at the front end along the inner diameter direction or the outer diameter direction when viewed axially.

5. The sliding component according to claim 2, characterized in that, A pressure relief groove extending circumferentially is provided between the inner diameter side deep groove and the outer diameter side deep groove.

6. The sliding component according to claim 1, characterized in that, A storage tank extending circumferentially is provided on the circumferentially extended portion of the deep groove.

7. The sliding component according to claim 1, characterized in that, The downstream end of the dynamic pressure generating groove is positioned between the adjacent deep grooves in the circumferential direction.

8. The sliding component according to claim 1, characterized in that, The sliding component has a reverse dynamic pressure generating groove extending circumferentially opposite to the dynamic pressure generating groove. The deep groove has a circumferential end that communicates with the upstream end of the reverse pressure generating groove in a relative rotational direction.

9. The sliding component according to claim 1, characterized in that, The sliding component is provided with a dynamic pressure generating element that communicates with the outer diameter space or the inner diameter space.

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