JPH08109969A - Hydraulic sealing device - Google Patents

Abstract

PURPOSE: To accelerate the formation and holding of an oil film at the press contact part of both the seal side surfaces, as for a hydraulic sealing equipment which is equipped with a seal ring groove and a seal ring installed in the seal ring groove which are in relative revolution and which is constituted so that both the seal surfaces are press-attached by the sealing hydraulic pressure. CONSTITUTION: A seal ring 12 is made of the synthetic resin having the prescribed elasticity, and the sealing side surface 12a is formed to a projecting curved surface having the high center part in the radial direction, and when the hydraulic pressure acts, a compression deformation is generated on the seal side surface 12a, and a hydraulic pocket 15 continuous to the press contact part can be formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an annular seal ring groove formed on one of opposing peripheral surfaces of a shaft member and a housing surrounding the shaft member which are rotatably disposed relative to each other. The present invention relates to a hydraulic seal device in which a seal ring that contacts a seal ring is mounted, and when the seal ring receives a hydraulic pressure, opposing seal side surfaces of the seal ring and the seal ring groove come into pressure contact with each other.

[0002]

2. Description of the Related Art Conventionally, in such a hydraulic seal device,
It is known that the seal ring is made of cast iron, the seal side surface is formed into a convex curved surface with a radial center portion raised, and the seal side surface is pressed against the flat seal side surface of the seal ring groove with hydraulic pressure. (For example, Kaikai 2
-122274).

[0003]

However, in the conventional apparatus as described above, since the sealing side surface of the seal ring has a convex curved surface, the contact between the sealing side surface and the sealing side surface of the seal ring groove seems to be smooth at first glance. Since the seal ring is made of cast iron and has a rigid body, the convex curved surface of the seal ring cuts into the seal side surface of the seal ring groove when the hydraulic pressure fluctuates, breaking the oil film between both seal side surfaces, and each seal due to poor lubrication. This may accelerate the wear of the side surface and impair the sealing performance and durability.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and uses a hydraulic pressure to improve formation and retention of an oil film between both seal side surfaces of a seal ring and a seal ring groove. An object of the present invention is to provide the hydraulic seal device that can exhibit durability.

[0005]

In order to achieve the above object, the present invention provides a seal ring groove having a flat sealing surface and a sealing ring having a convex curved surface having a raised radial center portion. The seal ring is made of a synthetic resin having elasticity so that the seal side surface of the seal ring can be elastically deformed so as to form a hydraulic pocket connected to the press-contact portion of the two seal surfaces during hydraulic operation. This is the feature of 1.

[0006] The present invention, in addition to the above characteristic, in that setting the hardness of the seal ring 80～120H _RM second
The feature of.

[0007]

According to the first feature of the present invention, when a hydraulic pressure is applied, the seal side surface of the synthetic resin seal ring is elastically deformed, and the hydraulic pocket connected to the seal ring groove and the pressure contact portion of both seal side surfaces of the seal ring is formed. The formation of the oil pocket suppresses the increase in the contact pressure between the two seal side surfaces, and the oil pressure is effectively supplied to the pressure contact portions of the both seal side surfaces by capillary action, thereby promoting the formation and holding of an oil film at the pressure contact portions. Is done.

In addition, when the oil pressure changes, the seal side surface of the seal ring is elastically deformed so as to change the volume of the hydraulic pocket, so that the contact pressure between the two seal side surfaces is hardly changed.

[0009]

An embodiment of the present invention will be described below with reference to the drawings.

First, in FIGS. 1 and 2, a shaft member 2 is integrally protruded from an inner wall of a fixed casing 1, and a housing 3 is rotatably fitted on the outer periphery of the shaft member 2. A thrust bearing is provided between the casing 1 and the housing 3. 9 is interposed.

The shaft member 2 is provided with an oil passage 4, the upstream side of which is connected to a hydraulic source such as an oil pump via a control valve (both not shown), and the downstream side of which is a shaft member. 2
It communicates with the oil passage 6 of the housing 3 through the annular groove 5 on the outer periphery. The oil passage 6 is connected to a hydraulic chamber 8 of a hydraulic actuator 7 such as a hydraulic clutch provided in the housing 3. Therefore, if the oil pressure of the oil pressure source is supplied to the oil passage 4, the oil pressure is transmitted to the hydraulic chamber 8 via the annular groove 5 and the oil passage 6, and the hydraulic actuator 7 can be operated.

A minute gap is provided between the opposing peripheral surfaces of the shaft member 2 and the housing 3 so as to allow relative rotation between the two, so that the oil pressure leaks to the outside from the annular groove 5 through the minute gap as much as possible. To prevent this, the following hydraulic seal device 10 is provided.

That is, the annular groove 5 is formed on the outer periphery of the shaft member 2.
Are formed, a pair of seal ring grooves 11, 11 are formed, and seal rings 12, 12 are mounted on these. Each seal ring 12 has one abutment 13, which is opened to be mounted in the seal ring groove 11.

In the above description, the shaft member 2 is made of an Al alloy, and the housing 3 is made of a steel plate. The seal ring 12 is made of a synthetic resin having a predetermined elasticity. For example, PES (polyether sulfone), PPS (polyphenylene sulfide), PEEK (polyether ether ketone),
PI (polyimide), PAS A (polyallyl sulfone) and the like are suitable, especially the hardness H _RM 80 to 120, tensile strength 700~1800kgf / cm ^2, the continuous heat resistance temperature 180 ° C.
The above is used.

Both axial side surfaces 11 of each seal ring groove 11
a and 11b are formed on a flat surface. These side surfaces 11a,
11b that is located outside of the annular groove 5
1a is referred to as a seal side surface of the seal ring groove 11.

On the other hand, in the seal ring 12 made of synthetic resin, the inner and outer peripheral surfaces 12i and 12o are formed in concentric cylindrical surfaces, and both axial side surfaces 12a and 12b are formed into a convex curved surface having a raised central portion in the radial direction. Formed, whereby the cross-sectional shape is barrel-shaped. The radius of curvature R of the convex curved surface is set to 3 to 130 mm, and desirably, approximately 11 mm. Here, of both side surfaces 12a and 12b of the seal ring 12,
The portion 12a located outside the annular groove 5 is referred to as a seal side surface of the seal ring 12.

In the free state, the outer diameter of the seal ring 12 is formed slightly larger than the inner diameter of the housing 3. When the seal ring 12 is mounted in the seal ring groove 12, the outer peripheral surface 12o of the seal ring 12 is It is designed to be substantially in close contact with the inner peripheral surface of the.

Next, the operation of this embodiment will be described.

In FIG. 1, when oil pressure is supplied from the oil passage 4 of the shaft member 2 to the oil passage 6 of the housing 3, the oil pressure is also transmitted to each seal ring groove 11 and the inner peripheral surface 12 i of each seal ring 12 is transmitted. In order to act on the inner side surface 11b, the seal ring 12 presses the outer peripheral surface 12o against the inner peripheral surface of the housing 3 and the outer side surface, that is, the seal surface 12a, against the seal side surface 11a of the seal ring groove 11. . If the housing 3 rotates with respect to the shaft member 2 in such a state, the outer peripheral surface 12o of each seal ring 12 and the housing 3
Is larger than the friction torque generated between the seal surfaces 12a and 11a of the ring 12 and the seal ring groove 11, the seal ring 12 rotates along with the housing 3. Side of both seals 11
a and 12a cause relative rotational sliding.

At this time, the two seal side faces 11a, 12
When observing FIG. 3A in detail, as shown in FIG. 3, since the sealing side surface 12a of the seal ring 12 has the above-mentioned convex curved surface, a triangular cross section is formed radially inward of the press-contact portions of the sealing side surfaces 11a and 12a. Of the seal ring 12 so that the oil that has entered the gap 14 expands the inner part of the gap 14 by its own pressure and centrifugal hydraulic pressure caused by rotation of the seal ring 12. 12a is subjected to compression deformation to form a hydraulic pocket 15 connected to the press-contact portion.

The contact area between the two seal side surfaces 11a and 12a is reduced due to the generation of the hydraulic pocket 15.
Acting in the direction of separating the a and 12a, the contact pressure between the two seal side surfaces 11a and 12a hardly increases. In addition, since the hydraulic pocket 15 is smoothly connected to the pressure contact portions of the two seal side surfaces 11a and 12a, good oil is supplied from the hydraulic pocket 15 to the pressure contact portion by capillary action, and the formation and holding of an oil film are effectively performed. And both seal side surfaces 11
a, 12a to prevent solid contact. Further, when the oil pressure changes, the amount of compressive deformation of the seal side surface 12a of the seal ring 12 changes and the volume of the hydraulic pocket 15 increases or decreases, so that the change in the contact pressure between the seal side surfaces 11a and 12a can be suppressed to a small value.

Thus, both seal side surfaces 11a, 11b
Can smoothly rotate and slide with each other, perform a good sealing action, and prevent leakage of hydraulic pressure to the outside of the seal ring groove 11. In this case, a small amount of oil leaks from the joint 13 of the seal ring 12, but the leaked oil is used for lubricating the contact portion between the shaft member 2 and the housing 3 and the thrust bearing 9. .

The following test was performed on the sealing device 1 of the present invention, and its performance was confirmed. (1) Contact pressure test on the side surface of the seal (see FIG. 4) As the test seal ring, three types of the seal ring made of PEEK of the present invention and the conventional one made of cast iron (R =
(3, 11, 130 mm) were prepared, and these were mounted in the seal ring grooves 11 of the shaft member 2 made of Al alloy, and the contact pressure of each seal ring and both seal side surfaces of the seal ring grooves when hydraulic pressure was applied was measured. FIG. 4 shows the results.

As is apparent from the test results, in the conventional cast iron seal ring, the magnitude of the radius of curvature R of the seal side surface has a strong influence on the contact pressure, and a change in the oil pressure also sensitively affects the change in the contact pressure. I do. In contrast, the effect of the PEEK seal ring of the present invention is relatively small, and the contact pressure is always low. In addition, the change in the contact pressure with respect to the change in the hydraulic pressure is small. Therefore, in the seal ring of the present invention, it is possible to make the dimensional accuracy of the radius of curvature R of the seal side surface rough at the time of molding, and furthermore, the contact pressure is stabilized irrespective of the change of the hydraulic pressure, and Therefore, the wear resistance of both the seal ring groove and the seal side surface of the seal ring can be expected to be improved. (2) A test of the relationship between the hardness of the synthetic resin seal ring 12 and the amount of wear of the Al alloy shaft 2 (see FIG. 5) Test conditions: hydraulic pressure 12 kgf / cm ² , oil temperature 120
° C, housing rotation speed: 6,500 rpm, test time
400hr ・ Seal ring 12: Material PEEK, size φ42
× 1.5 × 1.5 mm, R 11 mm ・ Shaft member 2: Material AC2B ・ Housing 3: Material FC25 FIG. 5A shows a shaft member when a seal ring 12 having a hardness of 70 to 130H _RM is attached. That is, a result of measuring the wear amount of the seal side surface 11a with the passage of time is shown. As is clear from this, if the wear amount of the shaft member 2 is not more than 30 μm after 50 hours from the start of the test, the wear of the shaft member 2 hardly progresses thereafter.

[0025] Therefore, when examining the hardness of the seal ring 12 to keep the wear amount of the shaft member 2 to 30μm or less when a lapse of 50 hours from the start of the test, in 80～120H _RM from the results shown in Fig. 5 (B) It turned out to be.

Therefore, the hardness of the seal ring 12 is set to 8
If set to 0～120H _RM, it is possible to ensure the durability of the shaft member 2, and by extension it can be maintained for a long period of time a good hydraulic sealing property.

In the above embodiment, various design changes can be made without departing from the gist of the present invention. For example, among the both side surfaces 12a and 12b of each seal ring 12, the inner side surface 12b close to the annular groove 5 does not participate in the sealing action, so that it can be formed as a flat surface. Alternatively, the seal ring groove 11 may be formed on the inner peripheral surface of the housing 3, and the inner peripheral surface of the seal ring 12 mounted on the housing 3 may be brought into contact with the outer peripheral surface of the shaft member 2.

[0028]

As described above, according to the first aspect of the present invention, the seal side surface of the seal ring groove is formed as a flat surface, and the seal side surface of the seal ring is formed as a convex curved surface having a raised central portion in the radial direction. Since the seal ring is made of a synthetic resin having elasticity so that the seal side surface of the seal ring can be elastically deformed so as to form a hydraulic pocket connected to the press-contact portion of the two seal surfaces during hydraulic operation, By utilizing the fluctuation, it is possible to effectively promote the formation and holding of an oil film in the pressure contact portions of the seal ring groove and the seal side of both seal rings, and the fluctuation of the contact pressure of both seal side surfaces even when the hydraulic pressure fluctuates. Can be kept small,
As a result, sealing performance and durability can be improved.

[0029] According to a second aspect of the present invention, since setting the hardness of the seal ring 80～120H _RM, the shaft member by a simple means of hardness setting of the seal ring, i.e. the sealing side of the seal ring groove The progress of abrasion of a predetermined amount or more can be suppressed, and the sealing performance and durability can be further improved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a hydraulic device including a hydraulic seal device of the present invention.

FIG. 2 is an enlarged view of a part of FIG. 1;

FIG. 3 is a further enlarged view of three parts of FIG. 2;

FIG. 4 is a diagram showing a test result of a comparison between a seal side contact pressure of the device of the present invention and a conventional device

FIG. 5 is a diagram showing a test result of a relationship between hardness of a seal ring and a wear amount of a shaft member in the device of the present invention.

[Explanation of symbols]

 2 Shaft member 3 Housing 4 Oil passage 6 Oil passage 10 Hydraulic sealing device 11 Seal ring groove 11a Seal side surface 12 Seal ring 12a Seal side surface 15 Hydraulic pocket

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor, Yohanori Kumagai 1-4-1, Chuo, Wako, Saitama Prefecture Inside Honda R & D Co., Ltd. (72) Takamichi Shimada, 1-4, Chuo, Wako, Saitama No. 1 Inside Honda R & D Co., Ltd. RIKEN Kashiwazaki Office

Claims (3)

[Claims] 1. A shaft member (2) disposed so as to be relatively rotatable.
And an annular seal ring groove (11) formed on one of the opposing peripheral surfaces of the housing (3) surrounding it.
Attach a seal ring (12) that contacts the other peripheral surface,
When the seal ring (12) receives a hydraulic pressure, the seal ring (12) and the seal side face (12a, 11a) of the seal ring groove (11) are brought into pressure contact with each other. The seal side surface (11a) of the seal ring (12) is flat and the seal side surface (11a) of the seal ring (12) is flat.
a) is formed on each of the convex curved surfaces whose central portions in the radial direction are raised, and the seal ring (12) is formed with a hydraulic pocket (15) which is continuous with the press-contact portions of the two seal surfaces (11a, 12a) when hydraulic pressure is applied. A hydraulic seal device characterized in that the seal side surface (12a) of the seal ring (12) is made of synthetic resin having elasticity so as to be elastically deformable. 2. A thing according to claim 1, characterized in that setting the hardness of the sealing ring (12) to 80～120H _RM, hydraulic sealing device. 3. The hydraulic sealing device according to claim 1, wherein the shaft member (2) is made of an Al alloy.