JPH11230368A - Sealing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the sealing properties of a sealing device in simple structure by enabling the formation of a bearing pressure distribution which exhibits satisfactory sealing properties to a slide surface and exhibiting the sealing properties in both directions. SOLUTION: A resin ring (sealing member) 2 is composed of a peripheral wall part 2a having a slide surface 2b, and a pair of flange parts 2c, 2d extending radially from a poison which is distant axially from the peripheral wall part 2. An O-ring 3 (urging member) is fitted between the flange parts 2c, 2d of the resin ring 2 so as to serve as a lever means for displacing the flange parts 2c, 2d so as to bend the peripheral wall part 2a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing device having a sealing member having a sliding surface and an urging member which comes into contact with the sealing member, and relates to a technique for improving the sealing performance.

[0002]

2. Description of the Related Art Conventionally, high-pressure sealed fluid (hydraulic oil, etc.)
A sealing device for preventing leakage of a sealed fluid from an annular gap between an inner peripheral surface of a shaft hole of a housing and an outer peripheral surface of a shaft inserted into the shaft hole in a driving force transmitting portion or the like of a device to which the device operates. Is provided.

FIG. 8 shows such a sealing device 100A, 1
00B, 100C (FIG. 8 (a),
(C), (e)) and a sectional configuration explanatory view (FIGS. 8 (b), (d), (f)) for explaining a usage pattern.

[0004] Each of the sealing devices 100A, 100B, 100C
Is a resin material (for example, PTFE or the like) disposed on the outer peripheral side
And O-rings 114, 115, and 116 made of a rubber-like elastic body that abuts on the inner peripheral side of these resin rings to apply an expanding force.

In FIGS. 8 (b), 8 (d) and 8 (f), the shaft hole 101a of the housing 101 and the shaft 102 are coaxially arranged, and the shaft 102 is stopped / rotated / oscillated according to the purpose. / An operation such as reciprocation is performed. And the axis 102
An annular groove 102b having a rectangular cross section is provided on the outer peripheral surface 102a of the device, and sealing devices 100A, 100B, and 100C are mounted.

The sealing devices 100A and 100B include resin rings 111 and 112 having a rectangular cross section.
The outer peripheral surfaces 111a, 112a (the outer peripheral wall surfaces of the resin ring when viewed in a cylindrical shape) of the housing 1
01 is a sliding surface with the shaft hole 101a.

Further, in the sealing device 100C, the cross-sectional shape of the resin ring 113 is left-right asymmetric in order to function as a one-sided seal capable of further preventing the fluid from entering in the direction of arrow A101 in the mounted state.

More specifically, the inclined surface portion 113a whose outer peripheral surface is reduced in diameter in the direction of arrow A101, and the inclined surface portion 113
8 is a cross-sectional shape having an outer peripheral contour in which a parallel surface portion 113b having a diameter slightly smaller than a is connected in the axial direction (the cross-sectional shape in FIG. 113b may be set smaller than that shown in the figure).

Therefore, the sealing device 100 having such a configuration is provided.
A, 100B, and 100C apply an expanding force to the resin ring having low elasticity by combining the resin ring and the O-ring, and apply a predetermined pressure to the opposing sliding surface (the shaft hole 101a of the housing 101 in FIG. 8). It has good sealing properties when brought into contact with it, and has excellent slidability / abrasion resistance due to the properties of the resin material.

[0010]

However, in the sealing devices 100A, 100B, the resin rings 111,
Since 112 receives the largest expansion force at the substantially central portion in the substantially axial direction by the O-rings 114 and 115, its outer peripheral surface 1
Pressure distribution PD100A, PD in 11a, 112a
100B has a chevron shape in which the surface pressure gradually increases toward the center, and the fluid easily enters from both ends from the axial end portion where the surface pressure is low, thereby deteriorating the sealing performance.

On the other hand, in the sealing device 100C, a surface pressure distribution PD100C having a steep rise is formed on the side where the withstand pressure is exerted (the left side in the figure).
Although the sealing performance in the direction of 101 is sufficient, the fluid easily enters from the opposite side (right side in the figure), and the sealing performance is reduced.

Further, in the sealing device 100C, since the outer peripheral wall surface is not a flat surface (cylindrical wall surface), the sealing devices 100A, 1
00B, and the inclined surface portion 113a
There was also a concern that the surface pressure distribution would change due to wear of the steel, which would lead to a reduction in sealing performance and life.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and it is an object of the present invention to form a surface pressure distribution exhibiting a good sealing property, and to improve a sealing property in both directions. An object of the present invention is to improve the sealing performance of the sealing device with a simple configuration, for example, to exert the effect.

[0014]

In order to achieve the above object, according to the present invention, an annular gap formed by two opposing surfaces is fitted into an annular groove formed on one of the surfaces, and the other is inserted into an annular groove formed on the other surface. A seal member having a sliding surface that abuts the surface,
In a sealing device provided with an urging member that abuts against the seal member and urges the other surface, the seal member is separated from the peripheral wall having the sliding surface in the axial direction of the peripheral wall. And a pair of flange portions each extending in a radial direction from a set position, wherein the biasing member is fitted between the flange portions of the seal member, and the flanges serve as lever means for bending the peripheral wall portion. The part is displaced.

With this arrangement, the sliding surface of the seal member is bent so as to be depressed in the axial direction with respect to the other surface with which the seal member is in contact, and has a surface pressure distribution having two peaks near the axial end of the sliding surface. Is formed.

The peak shape of the surface pressure distribution has a sharp rise outward in the axial direction and exhibits high sealing properties in both directions. For example, the two fluids are not mixed via a sealing device to be in a separated state. You can also.

Further, it is preferable that the pair of flange portions of the seal member have an interference allowance for the urging member fitted between them.

Thus, by combining the sealing member and the urging member, the flange portion can be forcibly displaced, and the bending of the sliding surface is reliably formed.

It is also preferable that the annular groove has a tapered portion at the bottom of the groove in contact with the end of the flange of the seal member.

Thus, when the end of the flange portion comes into contact with the tapered portion, the flange portion is pushed up to the other of the two opposing surfaces, and the surface pressure near the axial end of the sliding surface is increased. To further improve the sealing performance.

However, the end portion of the flange portion is also provided with a taper so that the flange portion is brought into contact with the tapered portion of the annular groove on the other surface side of the two opposing surfaces with respect to the axial center position of the urging member. The flange portion is prevented from functioning as lever means for bending the sliding surface into a convex shape (relative to the other of the two opposing surfaces).

Further, it is preferable that the flange portion of the seal member has a ridge portion which comes into contact with a side wall portion of the annular groove.

Thus, the flange functioning as the lever means can be displaced with the ridge as the fulcrum,
The flange portion can be further displaced, and the sliding surface is reliably bent.

It is also preferable that a groove is provided at substantially the center of the peripheral wall of the sealing member on the sliding surface side.

Therefore, the bending of the peripheral wall can be easily formed by the groove. In addition, by providing a seal ring made of a rubber-like elastic body, a porous (sponge-like) fluid holding member, and the like inside the groove, the sealability can be improved.

It is also preferable that the sliding surface of the peripheral wall of the sealing member is formed as a flat surface before the urging member is fitted between the flanges.

Therefore, the workability of the sliding surface of the peripheral wall of the seal member is not reduced.

Preferably, the seal member is formed of a resin material, and the urging means is formed of a rubber-like elastic material.

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (Embodiment 1) FIGS. 1 and 2 are views for explaining the structure of a sealing device 1 according to a first embodiment of the present invention. In FIG. 1, the sealing device 1
Are fitted into an annular groove 102b provided in the shaft 102, and the shaft hole 101a of the housing 101 as the two facing surfaces and the shaft 10
FIG. 5 is a cross-sectional configuration explanatory view (a view cut in an axial direction) of a main part illustrating a state in which an annular gap 106 between two outer peripheral surfaces 102a is sealed.

In FIG. 2, a resin ring 2 formed of a resin material as a sealing member and an O-ring 3 formed of a rubber-like elastic material as a biasing member are separately shown. Sectional view (Fig. 2
(A)) It is sectional drawing of the state which fitted the O-ring 3 in the resin ring 2 (FIG.2 (b)).

First, the members constituting the sealing device 1 will be described with reference to FIG.

The resin ring 2 is made of a resin material such as PTFE having excellent wear resistance and slidability. The outer peripheral surface of the peripheral wall portion 2a is formed as a sliding surface 2b which comes into contact with and slides on the shaft hole 101a of the housing 101. A pair of flange portions 2c and 2d extending radially are provided at both axial end portions on the inner peripheral side of the peripheral wall portion 2a.

An O-ring 3 is provided between the flanges 2c and 2d.
Is a holding groove 2e into which is fitted. The sliding surface 2
b is processed as a flat surface before the O-ring 3 is fitted.

In this embodiment, the O-ring 3 has a circular cross-sectional shape, and the dimension of the diameter W in the single state is related to the dimension of the width H of the holding groove 2e by the relation of W> H. It is set to be. That is, the holding groove 2 e has an interference allowance for the O-ring 3.

When the O-ring 3 is fitted into the resin ring 2 as shown in FIG.
2d is displaced in the directions of arrows A1 and A2, and functions as a lever means for bending the peripheral wall 2a. Therefore, the resin ring 2
Is also recessed in the axial direction.

Next, referring to FIG.
The state in which it is fitted in 2b and exerts a sealing function will be described.

The sliding surface 2b of the resin ring 2 is urged against the shaft hole 101a by an expanding force generated as a reaction when the O-ring 3 is crushed in the radial direction, and comes into contact with the shaft hole 101a. Since the sliding surface 2b is concave in the axial direction, surface pressure distributions PD1 and PD2 having two peaks near the axial end of the sliding surface are formed.

The shape of the peaks of the surface pressure distributions PD1 and PD2 has a sharp rise in the axial direction and a high sealing property in both directions (for the fluid entering from the directions of arrows A3 and A4 in the figure). Thus, for example, the two fluids can be separated from each other without mixing inside the housing 101 via the sealing device 1.

Accordingly, it is possible to form a surface pressure distribution which exerts a sealing property in both directions on the sliding surface 2b with a simple structure,
The sealing performance of the sealing device can be improved.

In this embodiment, the annular gap 106
Although the sealing device 1 is also formed in an annular shape in order to seal the ring, even when the two opposing surfaces are flat, the annular curvature is set to be large, and it can be applied by assuming that a part of the annular shape is used. is there.

(Embodiment 2) FIGS. 3, 4 and 5 show a sealing device 11 according to a second embodiment. FIG. 3 (a),
FIGS. 4B and 4C are cross-sectional views each independently showing the annular groove 102c of the resin ring 12, the O-ring 3, and the shaft 102. FIG. 4 shows the engagement relationship between the sealing device 11 and the annular groove 102c. FIG. 5 is a view showing an operation state of the sealing device 11.

In this sealing device 11, the resin ring 1 is inserted into the annular groove 102c of the shaft 102 into which the sealing device 11 is fitted.
Tapered portions 102d and 102e abutting on ends of the second flange portions 12c and 12d are provided on the groove bottom portion 102f (or a part of the side wall portions 102g and 102h of the annular groove 102c).

The flange portion 12 of the resin ring 12
The ends of c and 12d have tapered portions 12e and 12e having a gentle inclination with respect to the axial direction as compared with the tapered portions 102d and 102e.
12f is provided.

When the O-ring 3 is fitted into the resin ring 12 and is engaged with the annular groove 102c (see FIG. 4), the outer ends 12g and 12h of the tapered portions 12e and 12f of the resin ring 12 become tapered. 102d, 102
e, and the flange portions 12c, 12d are pointed at arrows A5, A
The stress which pushes up in 6 directions is generated and the peripheral wall portion 1
2a is bent, and the sliding surface 12b is depressed in the axial direction.

By employing such a structure, as shown in FIG. 5, the surface pressure distributions PD3 and PD4 having two peaks near the axial end of the sliding surface 12b.
Can be further increased, and the sealing performance in both directions is improved.

Since the ends 12g and 12h are located on the outer peripheral side of the center of the O-ring 3 in the axial direction, the flange 12c is used as lever means for bending the sliding surface 12b in a convex shape. , 12d are prevented from functioning,
More preferred.

(Embodiment 3) FIG. 6 is an explanatory sectional view of a sealing device 21 according to a third embodiment. The configurations of the housing 101 and the shaft 102 are the same as in the first embodiment. In addition, the same reference numerals are given to the same components as in the first embodiment for the sealing device 21.

The characteristic configuration of the sealing device 21 is provided with ridges 22 and 23 that are in contact with the side walls 102g and 102h of the annular groove 102b on the axially outside of the pair of flanges 2c and 2d of the resin ring 2. ing.

Thus, the flanges 2c and 2d functioning as lever means can be displaced with the ridges 22 and 23 as fulcrums, and the flanges 2c and 2d can be further displaced, so that the sliding surfaces can be reliably formed. 2b of bending is formed.

The other operations and effects are the same as those of the first embodiment, and the description thereof is omitted. In addition, the ridge 22,
Since the position of 23 is located on the outer peripheral side from the center position of the urging in the axial direction by the O-ring 3, the flange portions 2c and 2d are prevented from functioning as lever means for bending the sliding surface 2b in a convex shape. Is more preferable.

The protruding cross-sectional shape is not limited to a semicircular cross-section as in this embodiment, and other cross-sectional shapes such as a rectangular cross-sectional shape can be appropriately set.

(Embodiment 4) FIG. 6 is an explanatory view of a sectional configuration of a sealing device 31 according to a fourth embodiment. The configurations of the housing 101 and the shaft 102 are the same as in the first embodiment. In addition, the same reference numerals are given to the same components as in the first embodiment for the sealing device 31.

The characteristic structure of the sealing device 31 is that a groove 32 is provided at substantially the center of the sliding surface 2b of the resin ring 2.

Accordingly, the flange portion 2 is formed by the groove 32.
The flexures c and 2d can be easily formed. Also,
By providing a seal ring made of a rubber-like elastic body, a porous (sponge-like) fluid holding member, and the like inside the groove 32, it is possible to improve the sealing performance.

The other operations and effects are the same as those of the first embodiment, and the description thereof is omitted. Note that the cross-sectional shape of the groove 32 is not limited to the substantially U-shaped cross-section as in this embodiment, but an arcuate cross-sectional shape or a rectangular cross-sectional shape can be appropriately set.

[0056]

As described above, according to the sealing device to which the present invention is applied, it is possible to form a surface pressure distribution exhibiting a good sealing property on the sliding surface with a simple structure, and furthermore, in both directions. The sealing performance can be exhibited, and the sealing performance of the sealing device can be improved.

The pair of flange portions of the seal member have a squeezing allowance for the urging member fitted therebetween, so that the flange portion is forcibly displaced by combining the seal member and the urging member. Thus, bending of the sliding surface is reliably formed, and more stable sealing performance can be obtained.

Since the annular groove has a tapered portion at the groove bottom, the end of the flange portion comes into contact with the tapered portion and pushes up the flange portion to the other of the two opposing surfaces, and the axial end of the sliding surface. The surface pressure near the portion is increased to further improve the sealing performance.

By providing the flange with a ridge that abuts the side wall of the annular groove, the flange that functions as a lever means can be displaced with the ridge serving as a fulcrum.
The flange portion can be further displaced, and the sliding surface is reliably bent.

By providing a groove in a substantially central portion on the sliding surface side of the peripheral wall of the seal member, the peripheral wall can be easily bent, and the sealing performance can be further improved.

[Brief description of the drawings]

FIG. 1 is a sectional configuration explanatory view of a sealing device according to a first embodiment.

FIG. 2 is a diagram of components of the sealing device according to the first embodiment.

FIG. 3 is a diagram of a sealing device constituent member according to a second embodiment.

FIG. 4 is an explanatory cross-sectional configuration diagram of a sealing device according to a second embodiment.

FIG. 5 is a sectional configuration explanatory view of a sealing device according to a second embodiment.

FIG. 6 is a sectional configuration explanatory view of a sealing device according to a third embodiment.

FIG. 7 is an explanatory cross-sectional configuration diagram of a sealing device according to a fourth embodiment.

FIG. 8 is a view showing a conventional sealing device and surface pressure distribution characteristics of a sliding surface thereof.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sealing device 2 Resin ring (seal member) 2a Peripheral wall part 2b Sliding surface 2c, 2d Flange part 2e Holding groove 3 O-ring 101 Housing 101a Shaft hole 102 Axis 102a Outer peripheral surface 102b Annular groove 106 Annular gap PD1, PD2 Surface pressure distribution

Claims (7)

[Claims] 1. A seal member having a sliding surface fitted into an annular groove formed on one surface of an annular gap formed by two opposing surfaces and abutting on the other surface; In a sealing device provided with an urging member that abuts and urges the other surface, the sealing member includes a peripheral wall portion having the sliding surface, and a peripheral wall portion that is separated from an axial direction of the peripheral wall portion. A pair of flanges extending in a radial direction, wherein the biasing member is fitted between the flanges of the seal member, and displaces the flanges so as to be lever means for bending the peripheral wall. A sealing device characterized by the above-mentioned. 2. A pair of flange portions of the seal member,
The sealing device according to claim 1, further comprising a squeeze allowance for the urging member fitted therebetween. 3. The sealing device according to claim 1, wherein the annular groove includes a tapered portion at the bottom of the groove that abuts an end of a flange portion of the seal member. 4. The sealing device according to claim 1, wherein the flange portion of the sealing member includes a ridge that abuts on a side wall of the annular groove. 5. The sealing device according to claim 1, wherein a groove is provided at a substantially central portion on a sliding surface side of a peripheral wall portion of the sealing member. 6. A sliding surface of a peripheral wall portion of the seal member is formed as a flat surface before the urging member is fitted between the flange portions. The sealing device according to claim 1. 7. The sealing device according to claim 1, wherein the sealing member is formed of a resin material, and the urging means is formed of a rubber-like elastic material.