JP2001295943A - Seal ring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seal ring further improved in wear resistance while maintaining sealing performance. SOLUTION: A communicating hole 2 is formed as a stepped groove having a shallow groove bottom part 21 with the shallow groove bottom on the housing 60 side; a tapered part 22 gradually enlarging a space between a side wall surface 71a of an annular groove 71 and the tapered part 22 toward the groove bottom 71b of the annular groove 71; and a deep groove bottom part 23 with the deep groove bottom on the groove bottom 71b side of the annular groove 71.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seal ring for sealing an annular gap between two members provided rotatably relative to each other.

[0002]

2. Description of the Related Art Conventionally, this type of seal ring has been used for a hydraulic device such as an automatic transmission of an automobile.

A conventional seal ring will be described below with reference to FIGS. 6 and 7. FIG. Here, FIG.
FIG. 7 is a schematic cross-sectional view showing a state where a seal ring according to the related art is mounted, FIG. 7 is a schematic view of the seal ring according to the related art, (a) is a schematic partial plan view, and (b) is (A) is a bb cross-sectional view, and (c) is a side view as viewed from a direction c of (a).

The illustrated seal ring 100 includes a housing 200 provided with a shaft hole, and a shaft 3 inserted into the shaft hole.
For sealing the annular gap between the first and second 00,
It is used by being mounted on an annular groove 301 provided on the shaft 300.

[0005] The seal ring 100 is formed of a resin material, and has a first seal surface 101 for sealing a side wall surface of an annular groove 301 provided on the shaft 300 and a shaft hole provided in the housing 200. A second sealing surface 102 for sealing the peripheral surface.

[0006] From the sealed fluid side O to the non-sealed fluid side A
When pressure is applied in the direction of arrow P in FIG. 6, the seal ring 1 is pressed against the non-sealed fluid side A, so that the first seal surface 101 presses the side wall surface of the annular groove 301, The second sealing surface 102 presses the inner peripheral surface of a shaft hole provided in the housing 200 facing the annular groove 301, and seals at each position.

In this manner, leakage of the sealed fluid to the non-sealed fluid side A has been prevented.

Here, the sealed fluid is, for example, a lubricating oil, and particularly refers to an ATF when used for a transmission of an automobile.

In the above-described seal ring 100, particularly when the shaft 300 is made of a soft material such as an aluminum alloy, friction between the first seal surface 101 and the side wall surface of the annular groove 301 causes both the shaft 300 and the annular groove 301. Were worn out.

This is because the first sealing surface 101 and the annular groove 30
This is because it is difficult to form a lubricating film by the lubricating oil between the first side wall surface and the side wall surface of the first lubricating oil. .

As a technique for reducing such wear, a groove for supplying lubricating oil, which is a sealing fluid, between the first sealing surface 101 and the side wall surface of the annular groove 301 is provided. There is known a technique for improving abrasion resistance by forming a layer (see, for example, Japanese Patent Application Laid-Open No. 9-9636).
No. 3 publication).

That is, as shown in FIG. 7, by providing a communication groove 101a for connecting the sealed fluid side O and the non-sealed fluid side A to the first sealing surface 101, the lubricating oil on the sealed fluid side O can be removed. A lubricating film is formed between the first sealing surface 101 and the annular groove 301 when the first sealing surface 101 comes into sliding contact with the side wall surface of the annular groove 301 so that the first sealing surface 101 slides into the communication groove 101a to improve wear resistance. It is.

By providing the communication groove 101a, not only the formation of a lubricating film, but also foreign substances existing in the lubricating oil and abrasion powder generated by abrasion can be reduced. By providing a function of discharging the fluid to the non-sealed fluid side A so as not to be caught between them, the wear resistance is further improved.

It is generally considered that the cross-sectional shape of the communication groove 101a is rectangular, and according to Japanese Patent Application Laid-Open No. 9-96363, considering the removal of burrs generated during molding,
The angle β between the side wall surface of this groove and the sealing surface is an obtuse angle, that is, more than 90 ° and less than 180 °, preferably 120 °.
A technique of setting the angle between ° and 135 ° is disclosed.

[0015]

However, in the case of the above-described prior art, the following problems have occurred.

In the seal ring according to the prior art described above, the provision of the communication groove 101a improves wear resistance, but does not completely prevent wear. Although it is necessary to set the groove width and the groove depth, in order to maintain the sealing performance, it is necessary to suppress the leakage amount of the lubricating oil from the communication groove 101a to a certain extent. The depth must be as small as possible.

Therefore, when the wear progresses with time, the path to the communication groove is cut off, and when the supply of the lubricating oil to the communication groove is stopped, the lubricating film is not formed on the sliding contact portion. It causes wear.

This will be described in more detail with reference to FIG. FIG. 8 is a schematic cross-sectional view showing a state in which wear has progressed due to long-term use of a seal ring according to the related art.

As shown in FIG. 8, only the portion of the side wall surface of the annular groove 301 where the first sealing surface 101 is in sliding contact wears, so that the seal ring 100 is moved toward the side of the annular groove 301 by the worn amount. It will be pushed inward from the original position of the wall.

Therefore, when the bottom surface of the communication groove 101a reaches the unworn surface of the side wall surface of the annular groove 301, the path to the communication groove 101a is cut off as shown by the arrow X in FIG. In other words, lubricating oil is not supplied.

The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide a seal ring in which abrasion resistance is further improved while maintaining sealing performance. Is to do.

[0022]

According to the present invention, there is provided a seal ring for sealing an annular gap between two members provided so as to be relatively rotatable relative to each other. In a seal ring mounted on an annular groove provided on one of the members, a first seal surface for sealing a side wall surface of the annular groove provided on one of the members and the annular groove of the other member are opposed to each other. Second to seal the surface
A step provided on the sealing surface and the first sealing surface for communicating between the sealed fluid side and the non-sealed fluid side, and the groove bottom of the annular groove having a deeper groove bottom than the other member side; And a communication groove with an attached.

Therefore, even if the wear progresses with time, the communication groove is formed by making the groove bottom side of the annular groove deeper than that of the other member. Can be prevented from being shut off.

The side wall surface of the communication groove is preferably substantially perpendicular to the first sealing surface.

Thus, as compared with the case where the angle of the side wall surface with respect to the first seal surface is obtuse, even if the first seal surface wears over time, the degree of change in the sectional area of the communication groove is reduced. Can be suppressed.

[0026]

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the dimensions of the components described in this embodiment,
The materials, shapes, relative arrangements, and the like are not intended to limit the scope of the present invention only to them unless otherwise specified.

A seal ring according to an embodiment of the present invention will be described with reference to FIGS.

First, an overall configuration of a seal ring according to an embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a schematic view of a seal ring according to an embodiment of the present invention. FIG. 1A is a schematic plan view.
(B) is a partially enlarged view, and (c) is the cc of (b).
It is sectional drawing, (d) is the side view seen from the d direction of (b).

FIG. 2 is a schematic sectional view showing a state in which the seal ring according to the embodiment of the present invention is mounted.

As shown in FIG. 2, the seal ring 1 according to the present embodiment has an annular gap between two members provided rotatably relative to each other, that is, a housing 60 provided with a shaft hole, and a shaft 60 provided with the shaft hole. This is for sealing an annular gap between the shaft 70 inserted into the hole, and is used by being mounted on an annular groove 71 provided on the shaft 70.

The seal ring 1 is generally provided on a first seal surface 3 for sealing a side wall surface 71a of an annular groove 71 provided on a shaft 70 as one member and a housing 60 as the other member. A second sealing surface 4 for sealing the inner peripheral surface of the shaft hole.

In the figure, reference numeral 5 designates an abutment, and in the illustrated example, a special step cut is shown. In addition, a step cut, a straight cut, an endless cut,
There is no particular limitation such as bias cut.

Then, from the sealed fluid side O to the non-sealed fluid side A
When pressure is applied in the direction of arrow P in FIG. 2, the seal ring 1 is pressed against the non-sealed fluid side A, so that the first seal surface 3 presses the side wall surface 71 a of the annular groove 71. The second sealing surface 4 presses a portion facing the annular groove 71 on the inner peripheral surface of the shaft hole provided in the housing 60, and seals at each position.

Thus, leakage of the sealed fluid to the non-sealed fluid side A is prevented.

Note that the sealed fluid in the present embodiment is
This means a fluid having lubricity, and in the following description, lubricating oil will be described as an example.

In the seal ring 1 according to the present embodiment, the first sealing surface 3 has the sealed fluid side O and the non-sealed fluid side A
And a communication groove 2 for communicating with.

In the illustrated example, the communication groove 2 is provided at a slightly shifted position on the back surface of the first seal surface 3, but depending on the mounting direction of the seal ring 1, the communication groove 2 may be provided. Since it is not known whether the surface is used as a sealing surface (which surface is the first sealing surface 3), it is provided on both surfaces for convenience of mounting.

The communication groove 2 is a stepped groove.

That is, as shown in FIGS. 1 and 2,
The communication groove 2 has a tapered portion 22 such that the distance between the shallow groove bottom 21 on the housing 60 side and the side wall surface 71a of the annular groove 71 gradually increases toward the groove bottom 71b of the annular groove 71. And a deep groove bottom 23 having a deep groove bottom on the groove bottom 71b side of the annular groove 71.

As shown in FIG. 3, the stepped surface allows the side wall surface 7 of the annular groove 71 to be used for a long time, as shown in FIG.
As the wear of 1a and the first seal surface 3 progresses, the seal ring 1 is pushed inward from the original position of the side wall surface 71a of the annular groove 71, and the bottom surface of the shallow groove bottom 21 of the communication groove 2 is ,
Even if the side wall surface 71a of the annular groove 71 reaches the unworn surface, the flow path R is secured by the deep groove bottom 23.

Accordingly, the supply of the lubricating oil to the communication groove 2 can be maintained, and the wear resistance can be further improved.

Further, even if the abrasion progresses, since the supply of the lubricating oil can be ensured, it is not necessary to increase the groove cross-sectional area at the shallow groove bottom 21 of the communication groove 2 more than necessary. It is possible to maintain the sealing performance.

Here, in order to maintain the sealing performance,
It is necessary to secure a portion where the distance from the bottom of the communication groove 2 to the side wall surface 71a of the annular groove 71 is narrow.

Therefore, it is desirable that the above-described tapered portion 22 and deep groove bottom portion 23 be accommodated in the annular groove 71 when the seal ring 1 is mounted.

Here, the communication groove 2 will be described in more detail.

The width of the communication groove 2 is 0.05 to 0.35 mm, preferably 0.1 to 0.2 mm.

The depth (dimension A in FIG. 1C) of the shallow groove bottom 21 of the communication groove 2 is 0.05 to 0.35 mm, preferably 0.1 to 0.2 mm. good.

The length of the stepped portion (dimension B in FIG. 1C) obtained by combining the tapered portion 22 and the deep groove bottom 23 is equal to the thickness of the seal ring (dimension C in FIG. 1C). 10 for
７０70%, preferably 30-50%.

The depth of the groove at the deep groove bottom 23 (FIG. 1)
(C) Medium dimension D) may be 0.1 to 0.2 mm deeper than the groove depth of shallow groove bottom 21 (dimension A in FIG. 1C).

The angle of the tapered portion 22 (the angle α in FIG. 1C) is preferably not less than 90 ° and less than 180 °.

The angle (the angle β in FIG. 1D) of the side wall surface of the communication groove with respect to the first seal surface 3 is 90 ° or more and 12 ° or more.
The angle may be less than 0 °, preferably 92 ° to 100 °.
By making it approximately vertical in this way, the degree of change in the cross-sectional area of the groove can be suppressed even when wear progresses, so that the amount of leakage of lubricating oil can be stabilized and the sealing performance can be stabilized.

The number of communication grooves is preferably about 1 to 3 but may be appropriately set according to the diameter of the seal ring.

The arrangement of the communication grooves is, of course, not limited to that shown in the figure. For example, in order to supply the lubricating oil evenly to the entire first sealing surface 3 with a small number, FIG. The two grooves cross each other in an X-shape as in the communication groove 2a shown in FIG. 4A, or have a predetermined angle instead of the direction extending straight from the center of the ring as in the communication groove 2b shown in FIG. 4B. You may do it.

FIG. 5 also shows the cross-sectional shape of the communication groove.
It is not necessary to use a rectangular or trapezoidal shape like the communication groove 2c shown in (a), and it may be set appropriately. However, as described above, it is desirable that the degree of change in the cross-sectional area can be suppressed. The angle of the side wall surface with respect to the first seal surface 3 may be set to 90 ° to 120 °.
It is also preferable that the cross section be a hexagon as in the communication groove 2d shown in FIG.

As a material constituting the seal ring 1, a resin composition comprising a heat-resistant resin and a filler can be used.

Here, examples of the heat resistant resin include aromatic polyether ketone resins such as polycyano aryl ether resin (PEN) and polyether ether ketone (PEEK) resin, aromatic thermoplastic polyimide resin, and the like.
Resins exhibiting excellent mechanical properties such as polyamide 4-6 resin, polyphenylene sulfide resin, and polytetrafluoroethylene resin are excellent in heat resistance, flame resistance, and chemical resistance.

The filler is added for the purpose of improving the mechanical strength of the material, improving the abrasion resistance, imparting low friction characteristics, and the like, and is not particularly limited.

[0059]

EXAMPLES Hereinafter, more specific examples based on the above embodiment will be described.

First, as a molding material of the seal ring 1,
Polyetheretherketone resin (Sumitomo Chemical's Victrex PEEK 150G, heat deformation temperature 152 ° C),
The glass beads (Union Glass Product UB-47L, average particle diameter 75 μm) used after the aminosilane treatment were mixed at a mixing ratio of 85% by weight and 15% by weight, respectively, and the respective components were uniformly mixed using a Henschel mixer. Further, after melt-mixing at 400 ° C. using an extruder, the mixture was granulated with a pelletizer.

A seal ring having the shape shown in FIG. 1 was obtained by injection molding using the above materials.

The abutment is a special step cut, the height of the seal ring is 2.01 mm and the thickness is 1.91 m.
m and the outer diameter were 47.5 mm.

The width of the communication groove is 0.15 mm, the depth of the groove of the shallow groove bottom 21 is 0.15 mm, the length of the stepped portion (the size B in FIG. 1C) is 1 mm, and the depth of the deep groove bottom 23 is 23 mm. The groove depth (dimension D in FIG. 1 (c)) is 0.3 mm,
The angle of 2 (the angle α in FIG. 1C) is about 100 °, the angle of the side wall surface of the communication groove to the sealing surface (the angle β shown in FIG. 1D) is about 110 °, and the number of communication grooves Were formed one by one on both sides, shifted by 20 °.

With respect to the seal ring formed as described above and a seal ring (comparative example) which is different from the seal ring of the present embodiment only in that no communication groove is provided, the following durability test was performed. The wear amount and the leak amount before and after the durability test were compared.

The durability test was carried out in an environment of a temperature of 120 ° C., using an oil for automatic transmission (ATF) as a lubricant, a hydraulic pressure of 1.3 MPa, and a shaft rotation speed of 4000 rpm for 144 hours. Was.

The material of the cylinder serving as the housing was S45C, and the material of the shaft was ADC12.

FIG. 9 shows the results obtained by the above durability test.
And FIG. FIG. 9 shows a side view of the seal ring (first side).
The test results of the present embodiment and the comparative example are shown in the table for the wear amount of the seal surface), the wear amount of the shaft groove side surface (side wall surface of the annular groove), and the leak amount during the durability test, respectively. Is shown in the graph.

As can be seen from the test results, the sample of this example has a smaller amount of wear and a more stable leak than the comparative example.

In the above-described embodiments and examples, the configuration has been described in which the annular groove is provided on the shaft side and the seal ring is mounted in the annular groove. However, the annular groove is provided on the housing side. A configuration in which a seal ring is mounted thereon can be similarly applied.

That is, in this case, the first sealing surface of the seal ring is pressed against the side wall surface of the annular groove provided in the housing, and the second sealing surface is pressed against the outer peripheral surface of the shaft. The step may be configured so that the groove bottom on the groove bottom side of the annular groove is made deep as in the above-described embodiment and the like.

[0071]

As described above, according to the present invention, the communication groove is formed with a stepped groove in which the groove bottom is deeper on the groove bottom side of the annular groove than on the other member side. Even when the abrasion progresses, the supply of the sealing fluid to the communication groove can be ensured, and the abrasion resistance can be further improved while maintaining the sealing performance.

When the side wall surface of the communication groove is substantially perpendicular to the first seal surface, the degree of change in the cross-sectional area of the communication groove is suppressed even if the first seal surface wears over time. The sealing performance can be stabilized.

[Brief description of the drawings]

FIG. 1 is a schematic view of a seal ring according to an embodiment of the present invention.

FIG. 2 is a schematic sectional view showing a state where a seal ring according to the embodiment of the present invention is mounted.

FIG. 3 is a schematic cross-sectional view showing a state in which wear has progressed over time with use of the seal ring according to the embodiment of the present invention.

FIG. 4 is a schematic plan view showing an example of arrangement of communication grooves.

FIG. 5 is a schematic sectional view showing an example of a sectional shape of a communication groove.

FIG. 6 is a schematic sectional view showing a state in which a seal ring according to a conventional technique is mounted.

FIG. 7 is a schematic view of a seal ring according to the related art.

FIG. 8 is a schematic cross-sectional view showing a state in which wear of a seal ring according to the related art has progressed with time due to its use.

FIG. 9 is a table showing a comparison result of a wear amount and a leak amount in a durability test.

FIG. 10 is a graph showing a comparison result of a leak amount before and after a durability test.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Seal ring 2, 2a, 2b, 2c, 2d Communication groove 21 Shallow groove bottom 22 Taper part 23 Deep groove bottom 3 First sealing surface 4 Second sealing surface 5 Abutment 60 Housing 70 Shaft 71 Annular groove 71a Side wall surface 71b Groove bottom

Claims (2)

[Claims] 1. A seal ring for sealing an annular gap between two members provided rotatably relative to each other, wherein the seal ring is mounted in an annular groove provided in one of the two members. A first sealing surface for sealing a side wall surface of an annular groove provided on one member; a second sealing surface for sealing a surface of the other member opposed to the annular groove; and a first sealing surface provided on the first sealing surface. A stepped communication groove that communicates between the sealed fluid side and the non-sealed fluid side, and wherein the groove bottom side of the annular groove is deeper than the other member side. Seal ring. 2. The seal ring according to claim 1, wherein a side wall surface of the communication groove is substantially perpendicular to the first seal surface.