WO2016158848A1

WO2016158848A1 - Seal ring

Info

Publication number: WO2016158848A1
Application number: PCT/JP2016/059882
Authority: WO
Inventors: 南宣朴
Original assignee: 株式会社リケン
Priority date: 2015-03-31
Filing date: 2016-03-28
Publication date: 2016-10-06
Also published as: JPWO2016158848A1; JP6360566B2; CN207687346U; JP2017166703A

Abstract

Provided is a seal ring that can both reduce friction loss and control oil leaks. A seal ring comprises an outer circumferential face, an inner circumferential face that is opposite to the outer circumferential face, a side face that joins the outer circumferential face and the inner circumferential face, and a plurality of pockets that are provided on the side face with spaces therebetween and that are closed on the outer circumferential face side and opened on the inner circumferential face side. Each pocket has a first and second edge and a first and second inclined face. The first edge and second edge are provided on the ends in the circumferential direction, respectively, and are convex beveled faces that extend from the side face and project to the side face with tips having a radius of curvature of no more than 60 mm. The first and second inclined faces extend from the first and second edges, respectively, toward the center in the circumferential direction.

Description

Seal ring

The present invention relates to a seal ring that can be used for hydraulic equipment and the like.

An automobile equipped with various hydraulic devices such as a hydraulic automatic transmission is known. In such automobiles, it is desired to reduce the drive loss of hydraulic equipment in order to improve fuel efficiency.

シール Seal rings are used for hydraulic automatic transmissions. The seal ring is fitted into a groove portion of a shaft inserted through the housing, and seals between the housing and the shaft. In such a seal ring, when the automatic transmission is driven, friction loss (friction loss) occurs between the shaft and the shaft due to relative rotation with the shaft.

Such friction loss leads to driving loss of hydraulic equipment. Therefore, a technique for reducing friction loss is required. Patent Documents 1 to 5 disclose techniques for reducing friction loss generated between a seal ring and a shaft. The seal ring disclosed in these documents is provided with a pocket on the contact surface with the shaft.

¡When hydraulic pressure is applied to such a seal ring, the oil enters the pocket. The oil that has entered the pocket applies a force to the seal ring in a direction away from the shaft. Thereby, since the friction between a seal ring and a shaft is suppressed, the friction loss which arises between a seal ring and a shaft is reduced.

International Publication No. 2011/105513 Pamphlet International Publication No. 2004/090390 Pamphlet International Publication No. 2011/162283 Pamphlet International Publication No. 2013/094654 Pamphlet International Publication No. 2013/094657 Pamphlet

In the above technique, oil that has entered the pocket of the seal ring may flow between the seal ring and the shaft to form an oil film between the seal ring and the shaft. The formation of this oil film improves the lubricity of the seal ring and reduces friction loss. On the other hand, if the oil film becomes too thick, the oil tends to leak outside the seal ring. Thus, friction loss and oil leakage tend to be in a trade-off relationship.

In view of the circumstances as described above, an object of the present invention is to provide a seal ring capable of achieving both reduction of friction loss and suppression of oil leakage.

In order to achieve the above object, a seal ring according to an aspect of the present invention includes an outer peripheral surface, an inner peripheral surface facing the outer peripheral surface, a side surface connecting the outer peripheral surface and the inner peripheral surface, and the side surface. And a plurality of pockets that are closed at the outer peripheral surface side and open at the inner peripheral surface side.
Each of the plurality of pockets has first and second end portions and first and second slope portions.
The first and second end portions are convex R surfaces that are respectively provided at both ends in the circumferential direction and extend from the side surface and protrude toward the side surface having a tip curvature radius of 60 mm or less.
The first and second slope portions extend from the first and second end portions toward a circumferential central portion, respectively.

In this seal ring, depending on the rotation direction, the first end portion and the first slope portion, or the second end portion and the second slope portion receive hydraulic pressure from the oil in the pocket, thereby reducing friction loss. . That is, with this configuration, an effect of reducing friction loss can be obtained regardless of the rotation direction.
In particular, in this configuration, the first and second end portions are convex R surfaces. Thereby, in the first and second end portions, the inclination with respect to the side surface becomes gentler than that in the first and second slope portions, that is, the restriction of the oil flow path is reduced. Thereby, in this seal ring, since the oil in the pocket easily flows into the first and second end portions, the hydraulic pressure applied to the first and second end portions increases. In this configuration, the above-described effects can be effectively obtained by setting the tip curvature radii of the first and second end portions to 60 mm or less.
Further, in this seal ring, since the pocket is opened to the inner peripheral surface side and closed to the outer peripheral surface side, the oil entering the pocket is difficult to leak to the outer peripheral surface side.
Thus, in this seal ring, it is possible to achieve both reduction of friction loss and suppression of oil leakage by the interaction of the shape of the pocket and the number of pockets.

Each of the plurality of pockets may further include a bottom portion provided in a central region between the first end portion and the second end portion.
The first and second slope portions may extend from the first and second end portions to the bottom portion, respectively.
The bottom portion may extend in a direction parallel to the side surface.
In this seal ring, the oil pressure in the pocket can be satisfactorily received at the bottom, so that the friction loss can be further reduced.

The pocket may further include first and second connection portions that connect the bottom portion and the first and second slope portions, and are concave R surfaces that are recessed from the side surface side.
In this seal ring, the oil flowing into the pocket from the bottom can smoothly flow through the first and second slope portions. As a result, the hydraulic pressure from the oil is more favorably applied to the first and second slope portions.

The first slope portion and the second slope portion may be connected at the central portion.
In this seal ring, since the circumferential dimension of each pocket can be reduced, a large number of pockets can be provided. Thereby, in this seal ring, the friction loss can be further reduced.

The sum of the circumferential dimensions of the plurality of pockets on the inner peripheral surface may be not less than 50% and not more than 98% of the entire periphery of the inner peripheral surface.
In this seal ring, the effect of reducing the friction loss can be satisfactorily obtained by setting the ratio of the pockets on the inner peripheral surface to 50% or more. On the other hand, by keeping the ratio of the pockets on the inner peripheral surface to 98% or less, the pockets can be well separated by the pillars, so that the hydraulic pressure in each pocket can be ensured satisfactorily.

The first and second slope portions may be flat.
This configuration facilitates the design and processing of the seal ring.

The first and second slope portions may form an angle of 1 ° or more and 20 ° or less with respect to the side surface.
In this seal ring, the angle with respect to the side surfaces of the first and second slope portions is small, that is, the pocket is formed shallow. Thereby, the component toward the inner peripheral surface in the hydraulic pressure applied to the first and second slope portions by the oil in the pocket is increased. Moreover, since the restriction | limiting of an oil flow path becomes small, oil becomes easy to flow in into a 1st and 2nd end part. As a result, this seal ring can more effectively reduce the friction loss.

∙ It is possible to provide a seal ring that can reduce friction loss and suppress oil leakage.

It is a top view of the seal ring which concerns on one Embodiment of this invention. It is a fragmentary perspective view of the said seal ring. It is a figure which shows partially the internal peripheral surface of the said seal ring. It is a top view which shows the site | part which receives hydraulic pressure at the time of rotation of the said seal ring. It is a figure which shows partially the internal peripheral surface of the seal ring which concerns on the modification of the said embodiment. It is a figure which shows the seal ring concerning the comparative example 1. It is a figure which shows the seal ring concerning the comparative example 2. It is a figure which shows the seal ring concerning the comparative example 3. It is a graph which shows the result of friction loss evaluation. It is a graph which shows the result of oil leak evaluation.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[Seal ring 1]
FIG. 1 is a plan view of a seal ring 1 according to an embodiment of the present invention. The seal ring 1 has an outer peripheral surface 1a, an inner peripheral surface 1b, and a side surface 1c, and is formed in an annular shape centering on the central axis C. The outer peripheral surface 1a and the inner peripheral surface 1b are cylindrical surfaces centered on the central axis C, and the side surface 1c is orthogonal to the outer peripheral surface 1a and the inner peripheral surface 1b.

The seal ring 1 has a plurality of pockets 10 arranged at equal intervals on the two side surfaces 1c. Each pocket 10 is formed in a concave shape. Further, the seal ring 1 is provided with an abutment portion 30 for facilitating the mounting to the shaft as required. In addition, in this invention, the shape of the seal ring 1 in the case of having the joint part 30 shall be defined as the state which closed the joint part 30. FIG.

The joint part 30 is configured to be able to suppress oil leakage from the joint part 30. The shape of the abutment portion 30 is not particularly limited, and a known shape can be adopted. As the joint portion 30, for example, a right angle (straight) joint, an oblique (angle) joint, a stepped (step) joint, a double angle joint, a double cut joint, a triple step joint, or the like can be employed. In the double angle joint, the double cut joint, and the triple step joint, oil leakage from the joint part 30 is suppressed particularly well.

The seal ring 1 is attached to the groove portion of the shaft in a state where the joint portion 30 is widened. The shaft on which the seal ring 1 is mounted is inserted into the housing with the outer peripheral surface 1a of the seal ring 1 slightly protruding from the groove. Thereby, while the outer peripheral surface 1a of the seal ring 1 contacts the inner peripheral surface of a housing, the side surface 1c of the seal ring 1 contacts the groove part of a shaft. Thus, the seal ring 1 seals between the shaft and the housing.

The seal ring 1 is configured such that the pocket 10 is disposed in the groove portion of the shaft in a state where the seal ring 1 is mounted on the shaft and the housing. Therefore, a space is formed by the pocket 10 between the seal ring 1 and the groove portion of the shaft. In the seal ring 1, the hydraulic pressure of the oil flowing into the pocket 10 acts in a direction to separate the seal ring 1 and the shaft groove, so that the friction loss between the shaft groove and the shaft ring is reduced.

The diameter and thickness t ₀ (see FIG. 3) of the seal ring 1 can be determined according to the configuration of the shaft and housing to be mounted. The outer diameter of the seal ring 1 can be, for example, 10 mm or more and 150 mm or less. The thickness of the seal ring 1 _{t 0,} for example, can be set to 0.8mm or more 3.5mm or less.

The material forming the seal ring 1 is not limited to a specific type, but is polyether ether ketone (PEEK), polyphenylene sulfide (PPS), polyimide (PI), polytetrafluoroethylene (PTFE), modified polytetrafluoroethylene, Ethylene tetrafluoroethylene (ETFE) or the like can be used. Moreover, the material forming the seal ring 1 may be filled with additives such as carbon powder and carbon fiber.

The manufacturing method of the seal ring 1 is not limited to a specific method. For example, in the injection molding method or the compression molding method, the seal ring 1 provided with the pockets 10 can be directly manufactured. Examples of materials suitable for the injection molding method include resins such as PEEK, PPS, and PI. Examples of materials suitable for the compression molding method include resins such as PTFE. For example, for a resin such as PTFE, the seal ring 1 can be manufactured by machining the pocket 10 afterwards.

[Configuration of each pocket 10]
FIG. 2 is a partial perspective view showing a schematic configuration of the seal ring 1 and shows an enlarged pocket 10. FIG. 3 is a view showing the pocket 10 of the seal ring 1 from the inner peripheral surface 1b side. In FIG. 3, the shape along the inner peripheral surface 1b of the seal ring 1 is shown. The dimensions d ₀ , d ₁ , d ₂ shown in FIG. 3 indicate the dimensions along the circumferential direction of the inner peripheral surface 1 b of the seal ring 1.

The pocket 10 is provided on the inner peripheral surface 1 b side of the side surface 1 c of the seal ring 1. The pocket 10 includes a partition wall portion 15 between the pocket 10 and the outer peripheral surface 1 a of the seal ring 1, and the outer peripheral surface 1 a side is closed by the partition wall portion 15. Therefore, in the seal ring 1, the oil in the pocket 10 can be prevented from leaking to the outer peripheral surface 1 a side of the seal ring 1.

On the other hand, the pocket 10 does not have a partition portion between the pocket 10 and the inner peripheral surface 1b, and is open to the inner peripheral surface 1b side of the seal ring 1. Thereby, since it can prevent that the oil_pressure | hydraulic in the pocket 10 becomes high too much, it can suppress effectively that the oil in the pocket 10 leaks to the outer peripheral surface 1a side of the seal ring 1. FIG.

The partition wall 15 of the pocket 10 is not limited to a specific configuration as long as the space in the pocket 10 and the space on the outer peripheral surface 1a side can be separated. The partition wall portion 15 can be configured as a plane orthogonal to the side surface 1c of the seal ring 1, for example.

Each pocket 10 is separated in the circumferential direction of the seal ring 1 by a pillar portion 20 provided on the side surface 1c. That is, the pockets 10 and the column portions 20 are alternately arranged on the inner peripheral surface 1 b of the seal ring 1.

Dimension d ₁ of the dimension d ₀ and the column portion 20 of the pocket 10 may be suitably determined depending on the diameter of the seal ring 1, respectively. The dimension d _{0 of the} pocket 10 can be set to 2.0 mm or more and 35 mm or less, for example. Dimension _{d 1} of the cage bars 20 can be, for example, a 0.1mm or 5.0mm or less.

The shape of the pocket 10 is preferably symmetric with respect to a plane D indicated by a one-dot chain line in FIG. 3 at the center in the circumferential direction through the central axis C. Thereby, the function of the pocket 10 can be ensured irrespective of the rotation direction of the seal ring 1. The position and shape of the pocket 10 in the two side surfaces 1c of the seal ring 1 is configured to be symmetrical about the plane E of FIG. 3 in the central portion in the thickness t ₀ direction of the seal ring 1 by the dashed line ing.

The pocket 10 includes a bottom portion 11, first and

second slope portions

12a and 12b, first and

second end portions

13a and 13b, and first and

second connection portions

14a and 14b. The first and

second slope portions

12a and 12b, the first and

second end portions

13a and 13b, and the first and

second connection portions

14a and 14b are symmetric with respect to the plane D, respectively.

The bottom 11 is provided in the central region in the circumferential direction of the pocket 10 and is the deepest part of the pocket 10 from the side surface 1c. The bottom portion 11 functions as an oil inlet regardless of the rotation direction of the seal ring 1. The bottom portion 11 preferably extends in a direction parallel to the side surface 1c as a whole. The bottom 11 is typically planar, but need not be strictly planar. That is, the bottom portion 11 may be a gently curved surface. For example, the whole or a part thereof may be curved in a convex shape or a concave shape.

Depth _{t 1} from the dimension _{d 2} and the side surface 1c of the bottom part 11 may be appropriately determined. Dimension _{d 2} of the bottom portion 11, for example, be 0.01mm or less than 3mm. The depth t ₁ from the side surface 1c of the bottom 11 can be set to 0.1 mm or more and 0.6 mm or less, for example. The total depth _{t 1} from both sides 1c of the bottom part 11, for example, can be not more than 98% more than 50% of the thickness _{t 0} of the seal ring 1.

1st and

2nd slope part

12a, 12b is arrange | positioned with respect to the bottom part 11 mutually. In the example shown in FIGS. 2 and 3, the first slope portion 12 a is disposed on the right side of the bottom portion 11, and the second slope portion 12 b is disposed on the left side of the bottom portion 11. The first and

second slope portions

12a and 12b are inclined from the bottom portion 11 toward the column portion 20 so that the depth from the side surface 1c becomes shallow.

The first and

second slope portions

12a and 12b are preferably flat in terms of design and ease of processing. However, the first and

second slope portions

12a and 12b may be gentle curved surfaces instead of flat surfaces, and for example, the whole or a part thereof may be curved in a convex shape or a concave shape.

The angle α formed between the first and second

inclined surfaces

12a and 12b and the side surface 1c can be determined as appropriate. As the angle α is smaller, the component of the hydraulic pressure applied to the first and second

inclined surface portions

12a and 12b toward the inner peripheral surface 1b becomes larger. On the other hand, if the angle α is too small, it is difficult to apply hydraulic pressure to the first and

second slope portions

12a and 12b. From these viewpoints, the angle α can be set to 1 ° or more and 20 ° or less, for example.

1st and

2nd edge part

13a, 13b is comprised as a convex R surface which protrudes to the side surface 1c side, and is arrange | positioned at the both ends of the circumferential direction of the pocket 10. As shown in FIG. The first end portion 13 a connects the first slope portion 12 a and the column portion 20, and the second end portion 13 b connects the second slope portion 12 b and the column portion 20. In the example shown in FIGS. 2 and 3, the first end portion 13a is disposed on the left side of the first slope portion 12a, and the second end portion 13b is disposed on the right side of the second slope portion 12b.

The first and

second end portions

13a and 13b form a wedge-shaped oil flow path. Since the first and

second end portions

13a and 13b are configured as convex R surfaces, the inclination becomes gentler as the column portion 20 is approached. Therefore, the oil flow path formed by the first and

second end portions

13a and 13b becomes narrower as it becomes narrower. This makes it difficult for the oil to escape to the inner peripheral surface 1b side, that is, the oil easily enters deep into the first and

second end portions

13a and 13b, and therefore the hydraulic pressure applied to the first and

second end portions

13a and 13b. Will increase.

The shapes of the first and

second end portions

13a and 13b can be determined as appropriate. The first and

second end portions

13a and 13b may be formed with a single radius of curvature, or may be formed so that the radius of curvature continuously changes. The curvature radius (tip curvature radius) of the portion with the smallest curvature radius of the first and

second end portions

13a and 13b may be larger than 0 mm. Moreover, it is preferable that the front-end | tip curvature radius of 1st and

2nd edge part

13a, 13b is 60 mm or less, It is more preferable that it is 30 mm or less, It is still more preferable that it is 10 mm or less. By these, said effect is acquired effectively.

The first and

second connection portions

14a and 14b are configured as concave R surfaces that are recessed from the side surface 1c, and are disposed on both sides of the bottom portion 11 in the circumferential direction. The first connection portion 14 a connects the first slope portion 12 a and the bottom portion 11, and the second connection portion 14 b connects the second slope portion 12 b and the bottom portion 11. In the example shown in FIGS. 2 and 3, the first connection portion 14 a is disposed on the left side of the bottom portion 11, and the second connection portion 14 b is disposed on the right side of the bottom portion 11.

Since the first and

second connection portions

14a and 14b are configured as concave R surfaces, the oil flowing into the pocket 10 from the bottom portion 11 can smoothly flow to the first and

second slope portions

12a and 12b. Become. For this reason, in the seal ring 1, it is possible to receive the hydraulic pressure satisfactorily at the first and

second slope portions

12a and 12b.

The shapes of the first and

second connection portions

14a and 14b can be determined as appropriate. The first and second connecting

portions

14a and 14b may be formed with a single radius of curvature, or may be formed so that the radius of curvature changes continuously. The curvature radius (tip curvature radius) of the portion with the smallest curvature radius of the first and

second connection portions

14a, 14b may be larger than 0 mm. Further, the tip curvature radii of the first and

second connection portions

14a and 14b can be 60 mm or less, 30 mm or less, and 10 mm or less, like the first and

second end portions

13a and 13b. It can be.

[Position of pocket 10]
The seal ring 1 is provided with more pockets than a general seal ring. Thereby, in the seal ring 1, the number of parts that receive hydraulic pressure during rotation increases, that is, the interval between the parts that receive hydraulic pressure during rotation decreases. In the example shown in FIG. 1, twelve pockets 10 are provided.

FIG. 4 shows a portion that is mainly subjected to hydraulic pressure when the seal ring 1 rotates by hatching. FIG. 4A shows the case of rotating right in the direction of arrow R, and FIG. 4B shows the case of rotating left in the direction of arrow L.

In the seal ring 1 that is rotating clockwise as shown in FIG. 4A, the first inclined surface portion 12a and the first end portion 13a of each pocket 10 are subjected to hydraulic pressure, but the second inclined surface portion 12b and the second inclined surface portion 12b of each pocket 10 are used. The end 13b receives almost no hydraulic pressure. On the other hand, in the seal ring 1 that rotates counterclockwise as shown in FIG. 4B, the second inclined surface portion 12b and the second end portion 13b of each pocket 10 receive hydraulic pressure, but the first inclined surface portion of each pocket 10 12a and the 1st end part 13a receive little oil pressure.

As described above, in the seal ring 1, there is a portion that hardly receives hydraulic pressure in any rotation direction. If a portion of the seal ring 1 that hardly receives hydraulic pressure is continuously present in the circumferential direction, the hydraulic pressure applied to the entire seal ring 1 decreases and becomes unstable. As a result, the friction loss may not be sufficiently suppressed.

In that respect, in the seal ring 1, by increasing the number of pockets 10 compared to a general seal ring, the interval between the portions that receive the hydraulic pressure is narrowed, that is, the range of the portion that does not receive the hydraulic pressure is narrowed. As a result, the seal ring 1 can stably receive high hydraulic pressure from the oil in the pocket 10.

In the seal ring 1, when the number of the pockets 10 is four or more, the above effect can be obtained satisfactorily. On the other hand, by setting the number of pockets 10 to 40 or less, the hydraulic pressure applied to each pocket 10 can be ensured, so that the hydraulic pressure applied to the entire seal ring 1 can be kept high. For this reason, in the seal ring 1, it is preferable that the number of the pockets 10 is 4 or more and 40 or less.

Moreover, the sealing ring 1, it is also preferred that the total size _{d 0} of the pocket 10 is 98% or less 50% or more of the total circumference of the inner circumferential surface 1b. In the seal ring 1, when the proportion of the pockets 10 in the inner peripheral surface 1b is 50% or more, the effect of reducing the friction loss can be favorably obtained. On the other hand, in the seal ring 1, each pocket 10 can be well separated by the column portion 20 by keeping the proportion of the pockets on the inner peripheral surface 1b at 98% or less, so that the friction loss in each pocket 10 is reduced. The effect of reducing can be ensured.

[Modification]
With reference to FIG. 5, the seal ring 501 which concerns on the modification of the said embodiment is demonstrated. The seal ring 501 has the same configuration as the seal ring 1 according to the above-described embodiment except for the configuration described below. Moreover, the description about the structure similar to the seal ring 1 concerning the said embodiment in the seal ring 501 is abbreviate | omitted suitably.

FIG. 5 is a view showing the pocket 510 of the seal ring 501 according to the modification of the present embodiment from the inner peripheral surface 1b side. In FIG. 5, the shape along the inner peripheral surface 1b of the seal ring 501 is shown.

The seal ring 501 is not provided with the bottom 11 and the connecting

portions

14a and 14b according to the above embodiment. For this reason, the 1st and

2nd slope parts

12a and 12b comprise V shape by being connected directly. In addition, the 1st and

2nd slope parts

12a and 12b may be connected by the concave R surface, for example, even if it is not directly connected.

Bottom 11 and the connection portion 14a thus according to the above embodiment, the configuration is omitted 14b, dimension d ₀ of 510 of each pocket of the seal ring 501, the dimensions of each pocket 10 of the seal ring 1 according to the embodiment It is smaller than d _0. Thereby, in the seal ring 501, the number of the pockets 510 can be further increased.

In the seal ring 501, by increasing the number of pockets 510, that is, the number of the

slope portions

12a and 12b and the

end portions

13a and 13b, the number of portions that receive hydraulic pressure during rotation increases, and the interval between the portions that receive hydraulic pressure during rotation. Becomes narrower. Thereby, the seal ring 501 at the time of rotation can receive a higher hydraulic pressure from the oil in the pocket 510 more stably.

Thus, in the seal ring 501 according to the modified example, the friction loss during rotation can be further effectively reduced.

[Seal ring 1 according to the embodiment]
As an example of the present invention, a seal ring 1 having the configuration of the above embodiment was produced. The outer diameter of the seal ring 1 was 51 mm, and the number of pockets 10 was twelve. The seal rings 101, 201, and 301 according to Comparative Examples 1 to 3 described below are configured in the same manner as the seal ring 1 according to the present embodiment, except for the configuration that is specifically described.

[Seal ring 101 according to comparative example 1]
FIG. 6 is a view showing a seal ring 101 according to Comparative Example 1 of the present invention. 6A is a plan view of the seal ring 101, and FIG. 6B is a cross-sectional view of the seal ring 101 taken along the line AA ′ in FIG. 6A.

In the seal ring 101, the side surface 101c is inclined so that the interval is narrowed from the outer peripheral surface 101a toward the inner peripheral surface 101b. In the seal ring 101, friction loss is reduced by adopting a configuration in which the side surface 101c and the groove portion of the shaft are not in surface contact with each other.

[Seal ring 201 according to comparative example 2]
FIG. 7 is a view showing a seal ring 201 according to Comparative Example 2 of the present invention. 7A is a plan view of the seal ring 201, and FIG. 7B is a cross-sectional view of the seal ring 201 taken along line BB ′ of FIG. 7A.

The seal ring 201 is provided with eight pockets 210. Unlike the pocket 10 of the seal ring 1 according to the embodiment, the pocket 210 has an inclined surface that connects the inner peripheral surface 201b and the side surface 201c. In the seal ring 201, friction loss due to the pocket 210 is reduced while maintaining surface contact between the side surface 201c and the groove portion of the shaft.

[Seal Ring 301 According to Comparative Example 3]
FIG. 8 is a view showing a seal ring 301 according to Comparative Example 3 of the present invention. 8A is a plan view of the seal ring 301, and FIG. 8B is a partial perspective view showing the pocket 310 of the seal ring 301 in an enlarged manner.

The pocket 310 provided in the seal ring 301 extends along an area between the outer peripheral surface 301a and the inner peripheral surface 301b from an inflow port 311 provided in the inner peripheral surface 301b. The pocket 310 is configured such that the width and the depth from the side surface 301 c become smaller as the pocket 310 moves away from the inlet 311.

The seal ring 301 is configured so that oil flowing into the pocket 310 from the inlet 311 does not flow toward the inner peripheral surface 301b side while narrowing the oil flow path. The seal ring 301 has a configuration specialized for reducing friction loss by increasing the hydraulic pressure in the pocket 310.

[Friction loss evaluation]
Friction loss evaluation was performed using the seal ring 1 according to the example, the seal ring 101 according to comparative example 1, the seal ring 201 according to comparative example 2, and the seal ring 301 according to comparative example 3 as samples. For the friction loss evaluation, two samples were used, and drag torque (N · m) was measured at an oil temperature of 80 ° C. and an oil pressure of 0.5 MPa. The rotation speed of each sample in the measurement of drag torque was 1000 to 6000 rpm.

FIG. 9 is a graph showing the measurement results of drag torque. The horizontal axis in FIG. 9 indicates the rotation speed (rpm), and the vertical axis indicates the relative value of the drag torque.

A low drag torque is obtained in any of the seal ring 1 according to the example, the seal ring 101 according to the comparative example 1, the seal ring 201 according to the comparative example 2, and the seal ring 301 according to the comparative example 3, and the friction loss is reduced. It had been. Among them, in the seal ring 1 according to the example and the seal ring 301 according to the comparative example 3, it was found that a very low drag torque was obtained and the friction loss was more effectively reduced.

[Oil leak evaluation]
Oil leakage evaluation was performed using the seal ring 1 according to the example, the seal ring 101 according to the comparative example 1, the seal ring 201 according to the comparative example 2, and the seal ring 301 according to the comparative example 3 as samples. For oil leakage evaluation, two samples were used, and the amount of oil leakage (ml / min) was measured at an oil temperature of 80 ° C. and a hydraulic pressure of 0.5 MPa. The number of rotations of each sample in the measurement of the amount of oil leakage was 1000 to 6000 rpm.

FIG. 10 is a graph showing measurement results of the oil leakage amount. The horizontal axis in FIG. 10 indicates the rotational speed (rpm), and the vertical axis indicates the relative value of the oil leakage amount.

In any of the seal ring 1 according to the example, the seal ring 101 according to the comparative example 1, the seal ring 201 according to the comparative example 2, and the seal ring 301 according to the comparative example 3, the amount of oil leakage is small and the oil leakage is suppressed. It was. Among them, in the seal ring 1 according to the example and the seal ring 201 according to the comparative example 2, oil leakage hardly occurs regardless of the rotation speed, and the oil leakage is more effectively suppressed. all right. In addition, the seal ring 301 according to the comparative example 3 did not suit the seal ring 1 according to the example particularly at a high rotational speed, although good results were obtained at a low rotational speed.

[Summary]
In the seal ring 1 according to the example, better results than the seal ring 101 according to the comparative example 1 were obtained in both the friction loss evaluation and the oil leakage evaluation.
Further, in the seal ring 1 according to the example, a result comparable to the seal ring 201 according to the comparative example 2 is obtained for the oil leakage evaluation, and the better result than the seal ring 201 according to the comparative example 2 is obtained regarding the friction loss evaluation. was gotten.
Furthermore, in the seal ring 1 according to the example, a result comparable to the seal ring 301 according to the comparative example 3 is obtained for the friction loss evaluation, and the oil leakage evaluation is further better than the seal ring 301 according to the comparative example 3. was gotten.

As described above, only the seal ring 1 according to the example of the present invention obtained particularly good results in both the friction loss evaluation and the oil leakage evaluation. Thereby, it can be seen that the seal ring 1 can achieve both reduction of friction loss and suppression of oil leakage.

As mentioned above, although embodiment of this invention was described, this invention is not limited only to the above-mentioned embodiment, Of course, in the range which does not deviate from the summary of this invention, a various change can be added.

As an example, in the present invention, the shape of the pocket of the seal ring can be changed as appropriate. For example, the shape of each pocket need not be symmetric in the circumferential direction of the seal ring, and may be asymmetric in the circumferential direction of the seal ring.

In the present invention, a configuration in which pockets having the same configuration are provided on the two side surfaces of the seal ring is not essential. For example, the pocket may be provided on only one of the two side surfaces of the seal ring. Further, pockets having different configurations may be provided on the two side surfaces of the seal ring. Furthermore, the number of pockets may be different from each other on the two sides of the seal ring.

DESCRIPTION OF SYMBOLS 1 ... Seal ring 1a ... Outer peripheral surface 1b ... Inner peripheral surface 1c ... Side surface 10 ... Pocket 11 ...

Bottom part

12a, 12b ...

Slope part

13a, 13b ...

End part

14a, 14b ... Connection part 15 ... Partition part 20 ... Column part 30 ... Abutment

Claims

An outer peripheral surface, an inner peripheral surface opposed to the outer peripheral surface, a side surface connecting the outer peripheral surface and the inner peripheral surface, and a space between the side surfaces, the outer peripheral surface side being blocked, and the inner peripheral surface A plurality of pockets open on the surface side;
Each of the plurality of pockets is
First and second ends that are convex R surfaces that are provided at both ends in the circumferential direction and extend from the side surface and protrude toward the side surface with a tip radius of curvature of 60 mm or less;
A seal ring having first and second slope portions extending from the first and second end portions toward a circumferential central portion, respectively.
The seal ring according to claim 1,
Each of the plurality of pockets further comprises a bottom portion provided in a central region between the first end and the second end;
The first and second slope portions extend from the first and second end portions to the bottom portion, respectively.
The seal ring according to claim 2,
The bottom portion extends in a direction parallel to the side surface.
The seal ring according to claim 2 or 3,
The said pocket further has the 1st and 2nd connection part which is the concave R surface which connects the said bottom part and the said 1st and 2nd slope part, respectively, and is depressed from the said side surface side.
The seal ring according to claim 1,
A seal ring in which the first slope portion and the second slope portion are connected at the center portion.
The seal ring according to any one of claims 1 to 5,
The sum of the circumferential dimensions of the plurality of pockets on the inner peripheral surface is not less than 50% and not more than 98% of the entire periphery of the inner peripheral surface.
The seal ring according to any one of claims 1 to 6,
The first and second slope portions are flat seal rings.
The seal ring according to claim 7,
The first and second slope portions form an angle of 1 ° or more and 20 ° or less with respect to the side surface.