JPH11351401A - Sealing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure the stable sealing performance for a long period by comprising a inclined side wall surface on an annular groove, and forming an inclined end portion on a sealing member in a sealing device wherein the seaing member is mounted on the annular groove formed on one surface of the opposite surfaces, and the sealing member is energized to the other surface side by an energizing member. SOLUTION: A sealing device 1 is used for sealing an annular gap 4 between a shaft hole 2a of a housing 2 as two opposite surfaces and an outer peripheral surface 3a of a shaft 3, and a resin ring 5 as a sealing member is fitted in an annular groove 3b formed on the outer peripheral surface 3a. The resin ring 5 is energized to a housing 2 side by an energization ring 6. On this occasion, an inclined side wall surface 3d is formed on an anti-seal fluid side O of the annular groove 3b of the shaft 3, and an inclined end part 5c contacted with the inclined side wall surface 3b in parallel, is formed on the end part of the anti-seal fluid side O of the resin ring 5. Whereby the change in the shape of the bearing distribution of a sliding surface can be inhibited and the stable sealing performance can be ensured for a long period.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combination type sealing device which is fitted into an annular groove, and relates to a technique for improving the sealing performance by the structure of an annular groove and a sealing member.

[0002]

2. Description of the Related Art Conventionally, in a driving force transmitting portion of a device to which a high-pressure sealed fluid (such as hydraulic oil or fuel) acts, for example, an inner peripheral surface of a shaft hole of a housing and an outer periphery of a shaft inserted through the shaft hole. A sealing device is provided to prevent leakage of the sealing fluid from an annular gap between the surface (a rotary shaft for a shaft hole and a piston for a cylinder).

FIG. 6 shows such a sealing device 100A, 1
00B, 100C (FIG. 6 (a),
(C), (e)) and a sectional configuration explanatory view (FIGS. 6 (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 two O-rings 114, 115 and 116 made of a rubber-like elastic body which abuts on the inner peripheral side of these resin rings to apply an expanding force. is there.

In FIGS. 6 (b), 6 (d) and 6 (f), a shaft hole 101a of a housing 101 and a 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]

SUMMARY OF THE INVENTION A sealing device 100A, 1
In 00B, since the resin rings 111 and 112 receive the largest expansion force at the substantially central portion in the axial direction by the O-rings 114 and 115, their outer peripheral surfaces 111a and 112a
The surface pressure distributions PD100A and PD100B in have a symmetric mountain shape in which the surface pressure gradually increases toward the center.

Therefore, the fluid easily enters in both directions from the axial end having a low surface pressure. Further, as in the sealing device 100A shown in FIGS. 7A and 7B, the O-ring 114 receives pressure in the annular groove 102b and receives arrows A102 and A1.
In the case of movement in the axial direction of 03, the form of the surface pressure distribution PD100A changes depending on the position of the O-ring 114, and the sealing performance tends to be unstable, so it is generally used in a place where some leakage is allowed. Have been.

Further, as shown in FIG. 7 (c), even if two sealing devices 100A are arranged in the axial direction, the two-liquid sealing performance (for example, an attempt to invade in the directions of arrows A104 and A105 from both sides of the sealing device). Is not desirable because the surface pressure distribution PD100A is basically a symmetric mountain shape.

On the other hand, in the sealing device 100C, a surface pressure distribution PD100C having a sharp rise is formed on the side where the withstand pressure is exerted (the left side in the figure), and an arrow A
Since the sealability in the 101 direction is sufficient, two-liquid sealing performance can be exhibited by symmetrical mounting.

However, such a one-sided sealing type sealing device 100C has excellent sealing performance due to the large surface pressure peak at the large-diameter end (left side in the figure) of the inclined surface portion 113a. The sliding causes the abrasion of the inclined surface portion 113a, and also changes the surface pressure distribution shape, which may cause a reduction in sealing performance.

FIG. 8 is a view showing a state in which abrasion has occurred on the inclined surface portion 113a, and a surface pressure distribution PD100C in that state, which is closer to a symmetric mountain shape as compared with FIG. 6 (f).

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 suppress a change in the surface pressure distribution shape of a sliding surface and to exhibit stable sealing performance for a long period of time. It is an object of the present invention to provide a combination-type sealing device capable of performing a stable pressure distribution in an asymmetric mountain shape.

[0017]

According to the present invention, in order to achieve the above object, the present invention is arranged in an annular groove formed on one of two opposing surfaces forming an annular gap, A sealing member having a sliding surface that abuts on the other surface,
A biasing member disposed between the seal member and the groove bottom for biasing the seal member toward the other surface, wherein the annular groove has an inclined side wall surface; The seal member is provided with an inclined end portion that comes into contact with the inclined side wall surface of the annular groove and enables the seal member to slide to the other surface side as the sliding surface wears.

According to this configuration, the seal member is slid toward the other surface by the amount of wear of the sliding surface of the seal member by the urging force of the urging member, so that the change in the surface pressure distribution shape is small. Can be suppressed.

It is also preferable that the biasing member has a biasing center position with respect to the seal member on a side opposite to the inclined end portion with respect to the axial center portion of the seal member.

Accordingly, the peak position of the surface pressure distribution shape of the sliding surface of the seal member is on the side opposite to the inclined end, and it is possible to obtain a high sealing property in one direction as an asymmetric mountain shape. By symmetrically arranging this sealing device, it is also possible to form a two-way seal.

[0021]

(Embodiment 1) FIG. 1 is a view for explaining the configuration of a sealing device 1 according to a first embodiment of the present invention. The sealing device 1 seals an annular gap 4 between the shaft hole 2a of the housing 2 as an opposing surface and the outer peripheral surface 3a of the shaft 3, and is fitted into an annular groove 3b provided on the outer peripheral surface 3a. ing.

FIG. 2 shows a state in which a resin ring 5 (FIG. 2A) as a sealing member and an urging ring 6 (FIG. 2B) made of a rubber-like elastic body as an urging member are removed from the annular groove 3b. FIG. 4 is an explanatory view showing a state before being assembled to an annular groove 3b (FIG. 2C).

The structure of the sealing device 1 will be described below with reference to FIGS.

The annular groove 3b of the shaft 3 has a side wall surface 3c substantially perpendicular to the outer peripheral surface 3a on the sealed fluid side M and an inclined side whose diameter increases toward the non-sealed fluid side O on the anti-sealed fluid side O. It is composed of a wall surface 3d and a groove bottom 3e connecting the inner diameter side of the inclined side wall surface 3d to the side wall surface 3c.

The resin ring 5 is made of a PTFE material. The outer peripheral side of the resin ring 5 is in contact with the shaft hole 2 a of the housing 2, and the inner peripheral side is a pressure receiving surface 5 which receives the urging force of the urging ring 6.
b.

The end of the resin ring 5 on the anti-sealing fluid side O is in contact with the inclined side wall 3d of the annular groove 3b in parallel with the inclined end 5c and the sliding surface 5a is on the sealing fluid side M. And a substantially perpendicular side wall surface 5d.

The urging ring 6 is made of a rubber-like elastic material and is an annular member having a circular cross section. The urging ring 6 is disposed between the groove bottom 3e of the annular groove 3b and the resin ring 5, and is formed by an elastic repulsive force. Is urged to expand.

In the biasing ring 6, the annular groove 3b is not rectangular in cross section, and the axial width of the groove bottom 3e is narrower than the axial opening width due to the inclined side wall surface 3d. The movement amount due to the fluid pressure or the like received from M is also set to be small.

The biasing center of the biasing ring 6 indicated by an arrow A1 in FIG. 1 is located closer to the side wall surface 5d than the axial center of the resin ring 5.

Next, a description will be given of a sealing operation in a use mode in which the sealing device 1 is fitted into the annular groove 2b.

Since the sealing device 1 is a combination type of the resin ring 5 and the urging ring 6, the urging ring 6
Urges the resin ring 5 so that the resin ring 5
The sliding surface 5a is in sliding contact with the shaft hole 2a of the housing 2,
Heat resistance and abrasion resistance can be improved as compared with those having a sliding surface (seal lip) made of a rubber-like elastic body.

Since the biasing center position of the biasing ring 6 is located closer to the side wall surface 5d than the central portion in the axial direction of the resin ring 5, an asymmetric mountain-shaped surface having a peak on the side wall surface 5d side. A pressure distribution PD1 is formed.

The surface pressure distribution PD1 allows the sealing device 1 to function as a one-sided seal that can further prevent the fluid from entering from the direction of the sealed fluid M. Therefore, by providing a plurality of the sealing devices 1 in a symmetrical arrangement in the axial direction, it is possible to exhibit the two-liquid sealing performance.

FIGS. 3A and 3B show a state in which the sealing device 1 is mounted on the shaft 3 in a symmetrical arrangement (sealing devices 1A and 1B) in order to exhibit the two-liquid sealing performance.

In the arrangement shown in FIG. 3A, arrows A1, A
Sealing device 1A, 1B for pressure from two directions respectively
Is sealed on the outside in the axial direction. Further, in the arrangement shown in FIG. 3B, sealing is performed in a region indicated by an arrow A3 inside the sealing devices 1B and 1A in the axial direction.

Further, the shape of the surface pressure distribution PD1 is suppressed from changing because the movement amount (axial direction) of the urging ring 6 in the annular groove 2b is small, so that a stable sealing property can be obtained.

Further, in using the sealing device 1, FIG.
As shown in (a), when the wear Q1 of the sliding surface 5a occurs, the urging force of the urging ring 6 causes the resin ring 5 to be inclined by the amount of the wear Q1.
4d to the shaft hole 2a side (see FIG. 4).
(Refer to (b)), the change in the shape of the surface pressure distribution PD1 is suppressed to a small value, the change over time in the sealing property is small, and the initial sealing performance can be maintained for a long time.

The material of the resin ring 5 is PTFE
(Tetrafluoroethylene resin)
In order to further improve abrasion resistance and pressure resistance, PTFE resin containing filler such as fiber, and PFA,
Materials such as polyacetal and nylon can be appropriately used according to required specifications.

As the filler, carbon fiber, bronze (copper / tin, etc.), econol (trade name of aromatic polyester resin), graphite and the like can be used.

As the material of the biasing ring 6, fluorine rubber, nitrile rubber, nitrile hydroxide rubber, silicon rubber, ethylene propylene rubber, or the like can be appropriately used according to required specifications.

The present invention can be similarly applied to a configuration in which the sealing device 1 is mounted in an annular groove provided on the housing 2 side. (Embodiment 2) FIG. 5 is a view for explaining the structure of a sealing device according to a second embodiment of the present invention, in which a resin ring 25 (see FIG.
(A)) and the same biasing ring 6 as in FIG.
(FIG. 5B), and remove the annular groove 23b (FIG.
It is explanatory drawing in the state before assembling to (c)).

The feature of the second embodiment is that the inclined side wall surface 23d of the annular groove 23b and the resin ring 25
Is set in a round shape.

As described above, the side wall surface 23d and the inclined end portion 25c are formed.
Also in the case of having a round shape, good sealing properties can be obtained over a long period of time as in the first embodiment. It is also possible that only the inclined side wall surface on the groove side is tapered as in the first embodiment, and only the inclined end portion 25c of the resin ring 25 is rounded.

[0044]

As described above, according to the combination type sealing device to which the present invention is applied, in addition to the heat resistance and abrasion resistance obtained by the combination type sealing device, the surface pressure distribution on the sliding surface is also improved. A change in shape can be suppressed, and stable sealing performance can be exhibited over a long period of time.

Further, a high sealing performance in one direction due to the asymmetrical mountain-shaped surface pressure distribution can be stably obtained by the biasing center position of the biasing member. Therefore, the two-liquid sealing performance can be exhibited by symmetrically arranging the sealing devices.

[Brief description of the drawings]

FIG. 1 is a cross-sectional configuration explanatory view when a sealing device according to a first embodiment is mounted.

FIG. 2 is an explanatory cross-sectional configuration diagram before mounting of the sealing device according to the first embodiment;

FIG. 3 is a diagram in which the sealing device according to the first embodiment is symmetrically arranged.

FIG. 4 is a view for explaining an operation in a state where wear has occurred due to use of the sealing device according to the first embodiment;

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

FIG. 6 is an explanatory view of a cross-sectional configuration of a conventional sealing device.

FIG. 7 is a view for explaining a problem of the conventional sealing device.

FIG. 8 is a view for explaining a problem of the conventional sealing device.

[Explanation of symbols]

 Reference Signs List 1 sealing device 2 housing 2a shaft hole 3 shaft 3a outer peripheral surface 3b annular groove 3c side wall surface 3d inclined side wall surface 3e groove bottom 4 annular gap 5 resin ring (seal member) 5a sliding surface 5b pressure receiving surface 5c inclined end portion 5d side Wall 6 Urging ring (urging member) M Sealed fluid side O Anti-sealed fluid side PD1 Surface pressure distribution Q1 Wear

Claims (3)

[Claims] 1. A seal member which is arranged in an annular groove formed on one of two opposing surfaces forming an annular gap and has a sliding surface abutting on the other surface, A biasing member disposed between the member and the groove bottom for biasing the seal member toward the other surface, wherein the annular groove has an inclined side wall surface; The sealing device according to claim 1, further comprising: an inclined end portion that abuts on an inclined side wall surface of said annular groove and enables the seal member to slide toward the other surface side when the sliding surface is worn. 2. The sealing device according to claim 1, wherein the biasing member has a biasing center position with respect to the seal member on a side opposite to the inclined end portion with respect to an axial center portion of the seal member. 3. The sealing device according to claim 1, wherein the urging member is a rubber-like elastic body, and the sealing member is made of a resin material.