Sealing ring

Abstract

Provided is a seal ring capable of maintaining the degree of parallelism between sliding surfaces. A seal ring (3) is provided with: a sliding surface (3a) that rotates and slides relative to a shaft (1) or a housing (2) into which the shaft (1) is inserted; and an installation surface (3b) that intersects the sliding surface (3a) and is provided on the other one of the shaft (1) and the housing (2), the seal ring (3) dividing between one space (H) located on the opposite side of the side of the sliding surface (3a) that intersects the installation surface (3b) and the other space (L) disposed on the side that intersects the installation surface (3b), the one space (H) being located on the opposite side of the side of the sliding surface (3a) that intersects the installation surface (3b), and the other space (L) being located on the other side of the sliding surface (3a) that intersects the installation surface (3b). The present invention is provided with: a sliding surface (3a) that defines between one space (H) disposed on the opposite side of an installation surface (3b) and the other space (L) disposed on the installation surface (3b) side, the sliding surface (3a) being provided with: a dynamic pressure generation mechanism (36) that communicates with the one space (H) and has a dynamic pressure generation unit (39b); and a fluid recovery mechanism (37) that is positioned closer to the one space (H) side than the dynamic pressure generation unit (39b) and communicates with the relative rotation upstream side of the dynamic pressure generation mechanism (36).

Description

TECHNICAL FIELD

[0001] The present application relates to a seal ring used for shaft sealing of a gap between a shaft and a housing, and particularly to a seal ring used for installation in a ring-shaped groove, i.e., a so-called stuffing box. BACKGROUND

[0002] As a shaft seal device for preventing leakage of a sealed fluid, for example, there is a ring-shaped seal ring arranged between a rotating shaft and a housing of a rotating machine. In such a seal ring, in recent years, it is desired to reduce energy lost due to sliding for environmental countermeasures and the like.

[0003] For example, the seal ring shown in Patent Document 1 is fixed to the housing, and rotatably play-fitted in a ring-shaped groove provided to the rotating shaft, and a side surface of the seal ring can slide with respect to a side surface of the ring-shaped groove.

[0004] Further, an oil groove communicating with an oil chamber side and a wedge effect generation groove extending in a circumferential direction from the oil groove are provided to the side surface of the seal ring. At the time of rotation of the rotating shaft, working oil is taken in from the oil chamber by the oil groove, and dynamic pressure is generated by the wedge effect of the wedge effect generation groove, and the side surface of the seal ring is floated from the side surface of the ring-shaped groove to form an oil film. Thereby, it is possible to reduce the frictional force of the side surface of the seal ring with respect to the side surface of the ring-shaped groove.

[0005] PRIOR ART DOCUMENTS

[0006] PATENT DOCUMENTS

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 9-210211 (p. 4, Fig. 1) Figure 4 ) SUMMARY

[0008] PROBLEMS TO BE SOLVED BY THE INVENTION

[0009] In the seal ring of Patent Document 1, the seal ring is arranged so as to project to an outer diameter side compared to the ring-shaped groove of the rotating shaft, so that dynamic pressure based on the wedge effect generation groove is not generated at an outer diameter side portion of the side surface of the seal ring. Thereby, in the side surface of the seal ring, dynamic pressure is generated only at an inner diameter side portion, and thus it is possible that the seal ring is twisted in a manner that the inner diameter side portion is distanced from the side surface of the ring-shaped groove and the outer diameter side portion is approached to the side of the side surface of the ring-shaped groove, and the dynamic pressure generation effect is reduced.

[0010] The present application is completed in view of such a problem, and an object thereof is to provide a seal ring capable of maintaining parallelism of sliding surfaces to each other.

[0011] MEANS FOR SOLVING THE PROBLEMS

[0012] To solve the above problems, a seal ring of the present application has a sliding surface that rotates in sliding contact with a shaft or a housing into which the shaft is inserted, and a setting surface that is set in the other of the shaft and the housing, crossing the sliding surface, and divides a space on one side of the sliding surface opposite the side where the setting surface is crossed, and a space on the other side of the sliding surface on the side where the setting surface is crossed, wherein the sliding surface has a dynamic pressure generating mechanism that communicates with the space on one side, having a dynamic pressure generating portion, and a fluid recovery mechanism that is disposed at a position closer to the space on one side than the dynamic pressure generating portion, communicating with the opposite rotation upstream side of the dynamic pressure generating mechanism.

[0013] Thus, the pressure on the space on one side in the positive pressure generated near the dynamic pressure generating portion of the dynamic pressure generating mechanism is opened to the space on one side via the fluid recovery mechanism, so the pressure on the space on one side of the sliding surface can be suppressed. Also, the dynamic pressure generating mechanism communicates with the fluid recovery mechanism in addition to the space on one side, so sufficient fluid can be supplied to the dynamic pressure generating mechanism, so positive pressure can be reliably generated. Thus, twisting in which the space on one side of the sliding surface moves away from the space on the other side of the sliding surface and the space on the other side of the sliding surface moves closer to the space on one side of the sliding surface is not easily generated, so the parallelism of the sliding surfaces can be maintained.

[0014] Also, the fluid recovery mechanism can be formed longer in the circumferential direction.

[0015] Thus, the fluid between the sliding surfaces is easily recovered by the flow of the fluid within the fluid recovery mechanism.

[0016] Also, the fluid recovery mechanism can be a deep groove.

[0017] Thus, the fluid between the sliding surfaces can be taken in in large quantities, so the pressure of the space on one side of the sliding surface is easily reduced.

[0018] Also, the dynamic pressure generating mechanism can be composed of a fluid introduction groove that communicates with the space on one side, and a dynamic pressure generating groove that extends in the circumferential direction from the fluid introduction groove and is shallower than the fluid introduction groove, and the fluid recovery mechanism can communicate with the fluid introduction groove.

[0019] Thus, the sealed fluid can be efficiently introduced from the fluid introduction groove, which is a deep groove, to the dynamic pressure generating groove, so the dynamic pressure generating effect of the dynamic pressure generating portion is high. Also, since the fluid recovery mechanism communicates with the fluid introduction groove, which is a deep groove, the fluid recovery mechanism can be prevented from affecting the dynamic pressure generating effect of the dynamic pressure generating portion.

[0020] Also, the fluid recovery mechanism can communicate with the fluid introduction groove adjacent in the circumferential direction.

[0021] Therefore, it is easy to reduce the pressure on one side of the sliding surface evenly throughout the circumferential region. Attached Figure Description

[0022] Figure 1 This is a schematic cross-sectional view showing a shaft sealing device with a sealing ring applied according to Embodiment 1 of the present invention.

[0023] Figure 2 (a) is a diagram showing the sealing ring viewed from the axial direction. Figure 2 (b) is an enlarged view of the cut section viewed from the axial direction. Figure 2 (c) is the view observed along arrow A.

[0024] Figure 3 (a) is an enlarged view of the dynamic pressure generating tank and fluid recovery tank of Example 1, viewed from the axial direction. Figure 3 (b) is a sectional view along line AA.

[0025] Figure 4 This is a schematic cross-sectional view showing the state in which dynamic pressure is generated by the dynamic pressure generating groove.

[0026] Figure 5 This is an enlarged view of the dynamic pressure generating tank and fluid recovery tank of Embodiment 2 of the present invention, viewed from the axial direction.

[0027] Figure 6 This is an enlarged view of the dynamic pressure generating tank and fluid recovery tank of Embodiment 3 of the present invention, viewed from the axial direction.

[0028] Figure 7 This is an enlarged view of the dynamic pressure generating tank and fluid recovery tank of Embodiment 4 of the present invention, viewed from the axial direction.

[0029] Figure 8 This is an enlarged view of the dynamic pressure generating tank and fluid recovery tank of Embodiment 5 of the present invention, viewed from the axial direction.

[0030] Figure 9 This is a schematic cross-sectional view showing a shaft sealing device with a sealing ring applied according to Embodiment 6 of the present invention.

[0031] Figure 10 This is a schematic cross-sectional view showing a shaft sealing device with a sealing ring applied according to Embodiment 7 of the present invention.

[0032] Figure 11 This is an enlarged view of a modified example of the fluid recovery tank of Embodiment 1 of the present invention, viewed from the axial direction. Detailed Implementation

[0033] Hereinafter, the manner in which the sealing ring is used to implement the present invention will be described based on embodiments.

[0034] Example 1

[0035] Reference Figures 1 to 4 The sealing ring of Example 1 will be described. Furthermore, in this example, the sealing ring will... Figure 1 The right side of the paper serves as the right side of the sealing ring. Figure 1 The left side of the paper is used as the left side of the sealing ring for explanation. In addition, for ease of explanation, the dynamic pressure generating tank 36, fluid recovery tank 37, etc. are shown as larger than their actual size.

[0036] Figure 1 The illustrated shaft sealing device is preferably used, for example, in rotating equipment to seal the annular gap between a rotating shaft 1 and a housing 2 to maintain hydraulic pressure. In this embodiment, an example of such an application will be described. Furthermore, in... Figure 1 The image shows a state where no dynamic pressure is generated in the dynamic pressure generating groove 36 of the sealing ring 3.

[0037] The shaft sealing device mainly consists of a rotating shaft 1 (which serves as the shaft), a housing 2, and a sealing ring 3. The sealing ring 3 is fitted into an annular groove 1A with a rectangular cross-section, which is provided on the rotating shaft 1.

[0038] As described later, the right surface 3a of the sealing ring 3, which serves as the sliding surface, slides against the right surface 1a of the annular groove 1A, which serves as the opposing sliding surface. The outer peripheral surface 3b of the sealing ring 3, which serves as the setting surface, is pressed against the inner peripheral surface 2a of the housing 2, which serves as the setting surface. That is, it is sufficient for the setting surface and the setting surface to be in contact with each other. For example, they can be assembled in such a state that, when the equipment is started or when the lubrication of the sliding surface is insufficient, circumferential sliding between the setting surface and the setting surface is allowed.

[0039] Furthermore, the right surface 3a of the sealing ring 3 has a portion that abuts against the right surface 1a of the annular groove 1A and a portion disposed at a position closer to the outer diameter side than the right surface 1a of the annular groove 1A. In this embodiment, the sliding surface of the sealing ring 3 refers to the entire surface of the right surface 3a of the sealing ring 3. That is, the sliding surface of the sealing ring 3 includes the portion that abuts against the right surface 1a of the annular groove 1A and the portion that is coplanar with that portion.

[0040] Furthermore, the angles between the outer peripheral surface 3b and the right surface 3a, and between the outer peripheral surface 3b and the left surface of the sealing ring 3, are stepped portions obtained by cutting. This facilitates maintaining the press-fit state between the outer peripheral surface 3b and the inner peripheral surface 2a. This is because the sealing ring 3 can undergo minor deformation under external forces such as fluid pressure.

[0041] In this embodiment, the configuration is as follows: Figure 1The sealing ring 3 maintains the fluid pressure in the sealing target area (H) on the left side of the figure, which is affected by fluid pressure changes. The sealing target area (H), which is one space, is positioned on the opposite side of the outer peripheral surface 3b with reference to the right surface 3a of the sealing ring 3, and the leakage area (L), which is the other space, is positioned on the side of the outer peripheral surface 3b with reference to the right surface 3a of the sealing ring 3.

[0042] Furthermore, although not illustrated, when the equipment using sealing ring 3 is stopped, the fluid pressure in the sealed area (H) is low, compared to... Figure 1 The leakage area (L) on the right side has the same pressure. When the equipment is in operation, the fluid pressure in the sealed area (H) becomes higher than that in the leakage area (L).

[0043] The sealing ring 3 is made of resin materials such as polyetheretherketone (PEEK), polyphenylene sulfide (PPS), and polytetrafluoroethylene (PTFE).

[0044] like Figure 2 As shown in (a) to (c), the sealing ring 3 has a cut-off portion 31 formed at point 1 in the circumferential direction. Furthermore, Figure 2 (b) is Figure 2 Enlarged view of the enclosing part of (a).

[0045] The cutting section 31 is from both sides of the axial direction (see reference). Figure 2 (a), (b)) and the outer diameter side (refer to) Figure 2 (c) The known special stepped cut is cut in a stepped shape when observed. Thus, in the sealing ring 3, a first fitting protrusion 32 and a first fitting recess 33 are provided on the outer peripheral surface side on one circumferential side, and a second fitting recess 34 for fitting the first fitting protrusion 32 and a second fitting protrusion 35 fitting the first fitting recess 33 are provided on the outer peripheral surface side on the other circumferential side.

[0046] Furthermore, the cutting portion 31 includes not only cases where it is cut by machining, but also cases where it is formed by molding. Also, here, as an example of the cutting portion 31, a special stepped cut is shown, but it is not limited to this; known straight cuts, bevel cuts, stepped cuts, etc., can also be used. Additionally, if a low-elasticity material (such as PTFE) is used as the material of the sealing ring 3, the cutting portion may not be provided.

[0047] And, as Figure 2 (b) and Figure 3As shown, multiple dynamic pressure generating grooves 36 (serving as dynamic pressure generating mechanisms) and multiple fluid recovery grooves 37 (serving as fluid recovery mechanisms) are formed circumferentially on the right surface 3a of the sealing ring 3. In this embodiment, multiple groups of one dynamic pressure generating groove 36 and one fluid recovery groove 37 disposed downstream of the rotation axis 1 of the dynamic pressure generating groove 36 are provided circumferentially on the right surface 3a of the sealing ring 3.

[0048] Furthermore, the number of dynamic pressure generating grooves 36 and fluid recovery grooves 37 can be freely varied. For example, the number of dynamic pressure generating grooves 36 and the number of fluid recovery grooves 37 provided on the right surface 3a of the sealing ring 3 can also be different.

[0049] In particular, such as Figure 3 As shown in (a) and (b), the dynamic pressure generating tank 36 has a first tank portion 38 as a fluid inlet tank and a second tank portion 39 as a dynamic pressure generating tank.

[0050] The first groove 38 extends radially in a straight line from the inner diameter end 38a toward the outer diameter end 38b. The inner diameter end 38a communicates with the sealing target area (H). The outer diameter side of the outer diameter end 38b is closed by the land portion 40.

[0051] The second groove 39 extends in an arc shape from the outer diameter end 38b side of the first groove 38 toward the downstream side of the rotation direction of the rotating shaft 1. The second groove 39 is formed such that its circumferential length is longer than its radial groove width.

[0052] The second groove 39 becomes shallower from the upstream side toward the downstream side in the direction of rotation of the rotation axis 1. Specifically, the bottom surface 39a of the second groove 39 extends linearly from the side wall of the first groove 38 to the land portion 40 (see, in particular). Figure 3 (b)). In addition, the bottom surface 39a of the second groove 39 can also be stepped.

[0053] The end portion 39b of the second groove portion 39 is positioned closer to the outer diameter side than the center of the radial width of the right surface 3a of the sealing ring 3. In other words, the end portion 39b of the second groove portion 39, which is a pressure generating portion, is positioned close to the outer diameter side of the right surface 3a of the sealing ring 3, i.e., the leakage area (L) side.

[0054] like Figure 3 As shown in (b), the depth D1 of the first groove 38 is deeper than the depth D2 of the second groove 39 (D1 > D2). Specifically, the depth D1 of the first groove 38 is approximately 25 times the depth D2 of the second groove 39. Furthermore, the depth D2 of the second groove 39 referred to here is the depth of its deepest part. Figure 3 In (b), for ease of explanation, the depth D2 of the second groove 39 is shown as larger than the actual depth.

[0055] The fluid recovery tank 37 extends in an arc shape from the inner diameter end 38a side of the first tank portion 38 towards the upstream side in the rotation direction of the rotation axis 1. The circumferential component of the fluid recovery tank 37 is larger than the radial component. In addition, the fluid recovery tank 37 is not limited to being arc-shaped when viewed axially; for example, it may also extend in a straight line when viewed axially.

[0056] The fluid recovery tank 37 is in circumferential communication with the sealed object area (H).

[0057] Furthermore, the fluid recovery tank 37 and the first tank portion 38 of the dynamic pressure generating tank 36 adjacent to each other on the upstream side of the relative rotation are separated in the circumferential direction by the land portion 40.

[0058] Furthermore, referring to Figure 1 and Figure 3 (b) The depth D3 of the fluid recovery tank 37 is the same as the depth D1 of the first tank 38 (D1=D3).

[0059] In addition, in this embodiment, the depth D1 of the first groove 38 and the depth D3 of the fluid recovery groove 37 are approximately 25 times the depth D2 of the second groove 39, but can be freely changed, preferably about 5 to 50 times the depth.

[0060] The fluid recovery trough 37 is positioned closer to the inner diameter side than the center of the radial width of the right surface 3a of the sealing ring 3. In other words, the fluid recovery trough 37 is positioned close to the inner diameter side of the right surface 3a of the sealing ring 3, i.e., the sealing target area (H) side.

[0061] Furthermore, and importantly, the dynamic pressure generating groove 36 generates dynamic pressure over a wide radial range on the right surface 3a. Therefore, as described above, the dynamic pressure generating groove 36 is positioned closer to the outer diameter side than the center of the radial width of the right surface 3a. On the other hand, the fluid recovery groove 37 only needs to suppress excessive pressure on the inner diameter side of the right surface 3a. Therefore, it only needs to be positioned closer to the inner diameter side than the dynamic pressure generating groove 36. As described above, the fluid recovery groove 37 can be positioned closer to the inner diameter side than the center of the radial width of the right surface 3a of the sealing ring 3.

[0062] When the right surface 3a of the sealing ring 3 slides relative to the right surface 1a of the annular groove 1A, the oil in the dynamic pressure generating groove 36 moves toward the end 39b of the second groove 39, generating positive pressure at and near this end 39b. As a result, the right surface 3a of the sealing ring 3 slightly separates from the right surface 1a of the annular groove 1A (see reference). Figure 4 And an oil film is formed, thus reducing the friction between the right surface 3a of the sealing ring 3 and the right surface 1a of the annular groove 1A. In addition, oil can be supplied from the sealing target area (H) to the second groove 39 at any time via the first groove 38.

[0063] On the other hand, a portion of the oil in the fluid recovery tank 37 moves from the end 37b toward the first tank 38, while the other portion is discharged toward the sealed object area (H).

[0064] In this way, flow is generated within the fluid recovery tank 37 from end 37b toward the first tank portion 38, thereby recovering the fluid near the fluid recovery tank 37, thus... Figure 4 As shown, it is possible to reduce the pressure on the inner diameter side, i.e. the sealing target area (H) side, between the right surface 3a of the sealing ring 3 and the right surface 1a of the annular groove 1A, in the positive pressure generated by the dynamic pressure generating groove 36.

[0065] Furthermore, when the fluid recovery tank 37 is at a relative negative pressure, oil is supplied from the sealing target area (H). In other words, the fluid recovery tank 37 and the sealing target area (H) are at the same pressure.

[0066] Next, use Figure 1 , Figure 4 The state of the sealing ring 3 when the rotating shaft 1 rotates is described.

[0067] Reference Figure 1 When the equipment is in operation, the fluid pressure in the sealing area (H) becomes higher than that in the leakage area (L). Due to the fluid pressure in the sealing area (H), the sealing ring 3 is subjected to a force in the expansion direction, and the outer peripheral surface 3b of the sealing ring 3 is pressed against the inner peripheral surface 2a of the housing 2. That is, the sealing ring 3 is fixed to the housing 2.

[0068] Furthermore, the right surface 3a of the sealing ring 3 is pressed against the right surface 1a of the annular groove 1A of the rotating shaft 1 by the fluid pressure of the sealing target area (H) and slides.

[0069] like Figure 4 As shown, when the right surface 3a of the sealing ring 3 slides relative to the right surface 1a of the annular groove 1A, dynamic pressure is generated by the dynamic pressure generating groove 36, and the right surface 3a of the sealing ring 3 slightly separates from the right surface 1a of the annular groove 1A. Furthermore, in Figure 4 For ease of explanation, the separation width between the right surface 3a of the sealing ring 3 and the right surface 1a of the annular groove 1A is shown to be larger than the actual width in the diagram.

[0070] The diameter of the right surface 3a of the sealing ring 3 is larger than the diameter of the right surface 1a of the annular groove 1A. No dynamic pressure generating groove 36 is provided at the portion of the right surface 3a of the sealing ring 3 that extends outwards compared to the right surface 1a of the annular groove 1A. Therefore, on the right surface 3a of the sealing ring 3, a larger dynamic pressure acts on the inner diameter side compared to the outer diameter side. That is, a torsional force is applied to the sealing ring 3, causing it to move further away from the right surface 1a of the annular groove 1A than the outer diameter side of its inner diameter side.

[0071] In detail, a force is applied to the sealing ring 3 such that the right surface 3a of the sealing ring 3 is tilted relative to the right surface 1a of the annular groove 1A in the following manner: the portion of the sealing ring 3 on the inner diameter side relative to the center point P of the cross section is away from the right surface 1a of the annular groove 1A, and the portion of the sealing ring 3 on the outer diameter side relative to the center point P is close to the right surface 1a of the annular groove 1A.

[0072] In this embodiment 1, a fluid recovery groove 37 is provided on the right surface 3a of the sealing ring 3, at the end 39b of the second groove 39 of the specific pressure generating groove 36 near the sealing target area (H). Thus, the pressure on the sealing target area (H) side of the positive pressure generated near the end 39b of the second groove 39 is released to the sealing target area (H) via the fluid recovery groove 37, thereby suppressing the pressure on the sealing target area (H) side between the right surface 3a of the sealing ring 3 and the right surface 1a of the annular groove 1A.

[0073] Therefore, it is not easy for the sealing target area (H) side of the right surface 3a of the sealing ring 3 to be far away from the right surface 1a of the annular groove 1A and the leakage area (L) side to be close to the right surface 1a of the annular groove 1A, so that the parallelism between the right surface 3a of the sealing ring 3 and the right surface 1a of the annular groove 1A can be maintained. Therefore, it is possible to prevent the right surface 3a of the sealing ring 3 from contacting the right surface 1a of the annular groove 1A, and to prevent the reduction of the dynamic pressure effect of the dynamic pressure generating groove 36.

[0074] Furthermore, the first groove 38 of the dynamic pressure generating groove 36 is connected to the sealing target area (H) and also to the fluid recovery groove 37, so that sufficient fluid can be provided to the dynamic pressure generating groove 36, thus reliably generating positive pressure.

[0075] Furthermore, the circumferential component of the fluid recovery tank 37 is greater than its radial component, meaning it is longer in the circumferential direction. Therefore, it is possible to recover fluid between the right surfaces 1a and 3a over a large circumferential range in the fluid recovery tank 37.

[0076] Furthermore, the fluid recovery tank 37 is a deep groove, which can prevent dynamic pressure from being generated near the inner diameter end 38a of the first groove portion 38 between the right surface 3a of the sealing ring 3 and the right surface 1a of the annular groove 1A, thus efficiently reducing the pressure on the sealing target area (H) side. Moreover, the fluid can be recovered entirely in the fluid recovery tank 37.

[0077] Furthermore, the dynamic pressure generating groove 36 has a first groove 38 and a second groove 39. The first groove 38 is a deep groove, so oil can be efficiently introduced from the first groove 38 to the second groove 39, thus the dynamic pressure generating effect of the second groove 39 is high.

[0078] Furthermore, since the fluid recovery tank 37 is connected to the first tank section 38, which is a deep tank, it is possible to suppress the effect of the fluid recovery tank 37 on the dynamic pressure generated by the second tank section 39.

[0079] Furthermore, the second groove 39 becomes shallower from the upstream side to the downstream side in the rotation direction of the rotating shaft 1, so that the wedge effect of the second groove 39 can be used to efficiently generate dynamic pressure.

[0080] Furthermore, when viewed radially, the fluid recovery tank 37 overlaps with the second groove portion 39 of the hydrodynamic pressure generating tank 36 adjacent on the upstream side of relative rotation. Thus, the group of the hydrodynamic pressure generating tank 36 and the fluid recovery tank 37 adjacent on the upstream side of relative rotation can be arranged close together in the circumferential direction.

[0081] Furthermore, in this embodiment, the dynamic pressure generating groove 36 and the fluid recovery groove 37 are shown only on the right surface 3a of the sealing ring 3. However, it is also possible to provide the dynamic pressure generating groove and the fluid recovery groove on the left surface of the sealing ring 3 as well. Thus, for example, when from Figure 1 When the pressure balance in the regions on both sides reverses, the sealing ring 3 moves to the left, and its left surface contacts and slides against the left surface of the annular groove 1A. This allows it to generate dynamic pressure in the dynamic pressure generating groove on the left side and recover fluid in the fluid recovery groove on the left side. Furthermore, assembly can be performed regardless of orientation, enabling highly efficient operation.

[0082] Furthermore, in this embodiment, the depth of the second groove portion 39 of the dynamic pressure generating groove 36 is shown to gradually become shallower from the upstream side of relative rotation toward the downstream side of relative rotation, but the depth may also be constant.

[0083] Furthermore, in this embodiment, the depth of the fluid recovery tank 37 is shown to be the same as the depth of the first groove portion 38 of the dynamic pressure generating tank 36, but the depths of the first groove portion 38 and the dynamic pressure generating tank 36 may also be different. For example, the fluid recovery tank may be a shallow tank, and a relative negative pressure may be generated in the fluid recovery tank during relative rotation to improve the fluid recovery effect of the fluid recovery tank.

[0084] Example 2

[0085] Next, refer to Figure 5 The sealing ring of Example 2 will be described. Furthermore, repeated structural descriptions identical to those of Example 1 described above will be omitted.

[0086] like Figure 5 As shown, in this embodiment 2, a dynamic pressure generating groove 236 and a fluid recovery groove 237 are provided on the right surface 203a of the sealing ring 203. The dynamic pressure generating groove 236 has the same structure as the dynamic pressure generating groove 36 in embodiment 1.

[0087] The fluid recovery tank 237 extends in an arc shape from the inner diameter end 238a side of the first tank portion 238 toward the upstream side of the rotation direction of the rotating shaft 1. Moreover, the end of the fluid recovery tank 237 on the upstream side of the relative rotation is connected to the first tank portion 238 of the dynamic pressure generating tank 236 adjacent on the upstream side of the relative rotation.

[0088] That is, the fluid recovery tank 237 is formed in an annular shape over the entire circumference of its right surface 203a. This facilitates a uniform reduction in pressure on the sealing target area (H) side between the right surface 203a of the sealing ring 203 and the right surface 1a of the annular groove 1A throughout the circumferential direction. Furthermore, circumferential flow is easily generated within the fluid recovery tank 237, and the pressure within the fluid recovery tank 237 is easily uniform throughout the circumferential direction.

[0089] Example 3

[0090] Next, refer to Figure 6 The sealing ring of Example 3 will be described. Furthermore, repeated structural descriptions identical to those of Example 1 described above will be omitted.

[0091] like Figure 6 As shown, in this embodiment 3, a dynamic pressure generating groove 336 and a fluid recovery groove 337 are provided on the right surface 303a of the sealing ring 303. The dynamic pressure generating groove 336 has the same structure as the dynamic pressure generating groove 36 in embodiment 1.

[0092] The fluid recovery tank 337 extends in an arc shape upstream of the first tank portion 338 in the direction of rotation of the rotating shaft 1. The fluid recovery tank 337 is separated from the sealing target area (H) by the land portion 340. That is, the fluid recovery tank 337 communicates with the sealing target area (H) via the first tank portion 338.

[0093] By allowing fluid to flow from the upstream end 337b of the fluid recovery tank 337 toward the first groove 338, fluid near the fluid recovery tank 337 can be recovered. Therefore, even if the fluid recovery tank 337 is not directly connected to the sealing target area (H), the pressure on the sealing target area (H) side between the right surface 303a of the sealing ring 303 and the right surface 1a of the annular groove 1A can be reduced. Furthermore, since a land portion 340 is present on the inner diameter side of the fluid recovery tank 337, the fluid within the fluid recovery tank 337 can be easily maintained even if the pressure of the fluid in the sealing target area (H) fluctuates.

[0094] Example 4

[0095] Next, refer to Figure 7 The sealing ring of Example 4 will be described. Furthermore, repeated structural descriptions identical to those of Example 3 described above will be omitted.

[0096] like Figure 7As shown, in this embodiment 4, a dynamic pressure generating groove 436 and a fluid recovery groove 437 are provided on the right surface 403a of the sealing ring 403. The dynamic pressure generating groove 436 has the same structure as the dynamic pressure generating groove 36 in embodiment 1.

[0097] The end of the fluid recovery tank 437 on the upstream side of the relative rotation is connected to the first groove portion 438 of the hydrodynamic pressure generating groove 436 adjacent on the upstream side of the relative rotation. The fluid recovery tank 437 is separated from the sealing target area (H) by the land portion 440.

[0098] As a result, the pressure on the sealing target area (H) side between the right surface 403a of the sealing ring 403 and the right surface 1a of the annular groove 1A can be reduced equally in the circumferential overall range.

[0099] Furthermore, circumferential flow is easily generated in the fluid recovery tank 437, and the pressure is easily the same throughout the circumferential range within the fluid recovery tank 437.

[0100] Furthermore, since there is a land portion 440 on the inner diameter side of the fluid recovery tank 437, it is easy to maintain the fluid in the fluid recovery tank 437 even if the pressure of the fluid in the sealed target area (H) changes.

[0101] Example 5

[0102] Next, refer to Figure 8 The sealing ring of Example 5 will be described. Furthermore, repeated structural descriptions identical to those of Example 3 described above will be omitted.

[0103] like Figure 8 As shown, in this embodiment 5, a dynamic pressure generating groove 536 and a fluid recovery groove 537 are provided on the right surface 503a of the sealing ring 503. The dynamic pressure generating groove 536 has the same structure as the dynamic pressure generating groove 36 in embodiment 1.

[0104] A radially extending communication channel 541 is provided in the land portion 540 located between the fluid recovery tank 537 and the sealing target area (H). The communication channel 541 connects the fluid recovery tank 537 and the sealing target area (H) radially.

[0105] In this way, the fluid recovery tank 537 is connected to the sealing target area (H) in a portion of its circumferential direction through the connecting groove 541, thus facilitating the reduction of pressure on the sealing target area (H) side between the right surface 503a of the sealing ring 503 and the right surface 1a of the annular groove 1A.

[0106] Furthermore, since there is a land portion 540 on the inner diameter side of the fluid recovery tank 537, it is easy to maintain the fluid in the fluid recovery tank 537 even if the pressure of the fluid in the sealed target area (H) changes.

[0107] Example 6

[0108] Next, refer to Figure 9 The sealing ring of Example 6 will be described. Furthermore, repeated structural descriptions identical to those of Example 1 described above will be omitted.

[0109] like Figure 9 As shown, with the aid of fluid pressure, the right surface 603a, which serves as the mounting surface, is pressed against the right surface 1a of the annular groove 1A of the rotating shaft 1. In this embodiment 6, the sealing ring 603 rotates together with the rotating shaft 1.

[0110] The sealing ring 603 has a dynamic pressure generating groove 636 and a fluid recovery groove 637 formed on its outer peripheral surface 603b, which serves as a sliding surface. The dynamic pressure generating groove 636 and the fluid recovery groove 637 communicate with the sealing target area (H) on the opposite side of the right surface 603a on the outer peripheral surface 603b.

[0111] When the sealing ring 603 rotates together with the rotating shaft 1, the outer peripheral surface 603b of the sealing ring 603 slides with the inner peripheral surface 2a of the housing 2, generating dynamic pressure in the dynamic pressure generating groove 636, and the outer peripheral surface 603b of the sealing ring 603 separates from the inner peripheral surface 2a of the housing 2 to form an oil film.

[0112] At this time, at the position of the specific dynamic pressure generating groove 636 on the side near the sealing target area (H), the fluid between the outer peripheral surface 603b of the sealing ring 603 and the inner peripheral surface 2a of the housing 2 is recovered by the fluid recovery groove 637, the pressure on the sealing target area (H) side is reduced, so the tilting of the outer peripheral surface 603b of the sealing ring 603 and the inner peripheral surface 2a of the housing 2 can be suppressed.

[0113] Example 7

[0114] Next, refer to Figure 10 The sealing ring of Example 7 will be described. Furthermore, repeated structural descriptions identical to those of Example 1 described above will be omitted.

[0115] like Figure 10 As shown, in this embodiment 7, the shaft sealing device has an annular groove 72A formed in the housing 72, and a sealing ring 703 is disposed in the annular groove 72A. In addition, the outer peripheral surface 71a of the rotating shaft 71 extends flatly along the axial direction.

[0116] The inner circumferential surface 703d of the sealing ring 703, which serves as the mounting surface, is pressed against the outer circumferential surface 71a of the rotating shaft 71 by means of fluid pressure, and rotates together with the rotating shaft 71.

[0117] Furthermore, the right surface 703a of the sealing ring 703, which serves as the sliding surface, comes into contact with the right surface 72a of the annular groove 72A by means of fluid pressure, and can slide relative to each other.

[0118] A dynamic pressure generating groove 736 and a fluid recovery groove 737 are formed on the right surface 703a of the sealing ring 703. The dynamic pressure generating groove 736 and the fluid recovery groove 737 communicate with the sealing target area (H) on the opposite side of the right surface 703a and the inner peripheral surface 703d.

[0119] When the sealing ring 703 rotates together with the rotating shaft 71, the right surface 703a of the sealing ring 703 slides with the right surface 72a of the annular groove 72A, generating dynamic pressure in the dynamic pressure generating groove 736, and the right surface 703a of the sealing ring 703 separates from the right surface 72a of the annular groove 72A to form an oil film.

[0120] At this time, at the position of the specific dynamic pressure generating groove 736 on the side near the sealing target area (H), the fluid between the right surface 703a of the sealing ring 703 and the right surface 72a of the annular groove 72A is recovered by the fluid recovery groove 737, the pressure on the sealing target area (H) side decreases, and thus the tilting of the right surface 703a of the sealing ring 703 and the right surface 72a of the annular groove 72A can be suppressed.

[0121] 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 changes and additions that do not depart from the spirit of the present invention are also included in the present invention.

[0122] For example, in the aforementioned embodiments 1 to 7, the sliding surface of the sealing ring is shown to be perpendicular to the setting surface, but it is not limited to extending in the direction where the sliding surface and the setting surface intersect.

[0123] Furthermore, in the aforementioned embodiments 1 to 7, the method of rotating the shaft relative to the housing was illustrated, but it is also possible that the housing rotates relative to the shaft, or that the shaft and the housing rotate together in the relative rotation direction.

[0124] Furthermore, in the aforementioned Examples 1 to 7, an example was shown in which the circumferential component of the fluid recovery mechanism is larger than the radial component, but it is also possible for the radial component to be larger than the circumferential component.

[0125] Furthermore, in the aforementioned embodiments 1 to 7, the dynamic pressure generating mechanism is illustrated as being composed of a fluid inlet groove and a dynamic pressure generating groove, but it could also be, for example, a spiral groove.

[0126] Furthermore, in the aforementioned embodiments 1 to 7, a method in which the depth of the fluid recovery mechanism is constant was illustrated, but the depth can also be varied. For example, it can also be as follows: Figure 11As shown, the fluid recovery tank 837 gradually becomes shallower from the downstream end 838a towards the upstream end 837b. This allows a relative negative pressure to be generated at the upstream end 837b of the fluid recovery tank 837, facilitating the intake of fluid between the sliding surfaces. Furthermore, since the downstream end 838a is a deep tank, dynamic pressure is less likely to be generated near the downstream end 838a.

[0127] Label Explanation

[0128] 1: Rotating shaft (shaft); 1A: Annular groove; 1a: Right side (sliding surface); 2: Housing; 2a: Inner circumferential surface (setting surface); 3: Sealing ring; 3a: Right side (sliding surface); 3b: Outer circumferential surface (setting surface); 36: Dynamic pressure generating groove (dynamic pressure generating mechanism); 37: Fluid recovery groove (fluid recovery mechanism); 38: First groove section (fluid inlet groove); 39: Second groove section (dynamic pressure generating groove); 39b: End (dynamic pressure generating part); 40: Land section.

Claims

1. A seal ring, comprising: a sliding surface that rotates in sliding contact with a shaft or a housing into which the shaft is inserted; and a setting surface that is disposed in the other of the shaft and the housing, crossing the sliding surface, the seal ring dividing a space on one side of the sliding surface opposite the side on which the setting surface is disposed from a space on the other side of the sliding surface on which the setting surface is disposed, wherein the sliding surface has: a dynamic pressure generating mechanism that communicates with the space on one side and has a dynamic pressure generating portion; and a fluid recovery mechanism that is disposed at a position closer to the space on one side than the dynamic pressure generating portion and communicates with an opposite-rotation upstream side of the dynamic pressure generating mechanism.

2. The seal ring according to claim 1, wherein the fluid recovery mechanism is formed longer in the circumferential direction.

3. The seal ring according to claim 1, wherein the fluid recovery mechanism is a deep groove.

4. The seal ring according to any one of claims 1 to 3, wherein the dynamic pressure generating mechanism is composed of a fluid introduction groove that communicates with the space on one side and a dynamic pressure generating groove that extends in the circumferential direction from the fluid introduction groove and is shallower than the fluid introduction groove, the fluid recovery mechanism communicating with the fluid introduction groove.

5. The seal ring according to claim 1, wherein the fluid recovery mechanism communicates with the fluid introduction groove that is adjacent in the circumferential direction. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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