JP3804257B2 - Sealing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sealing device including a sealing member having a sliding surface and an urging member that comes into contact with the sealing member, and is a technique for improving the sealing performance.
[0002]
[Prior art]
Conventionally, in a driving force transmission portion of a device on which a high-pressure sealing fluid (hydraulic oil or the like) acts, an annular gap between the inner peripheral surface of the shaft hole of the housing and the outer peripheral surface of the shaft inserted through the shaft hole A sealing device is provided to prevent leakage of the sealing fluid.
[0003]
FIG. 8 is a schematic cross-sectional configuration (FIGS. 8A, 8C, and 8E) of such a sealing device 100A, 100B, and 100C, and a cross-sectional configuration explanatory diagram that explains the usage mode (FIG. 8B). , (D), (f)).
[0004]
Each of the sealing devices 100A, 100B, and 100C includes resin rings 111, 112, and 113 made of a resin material (for example, PTFE) disposed on the outer peripheral side, and a rubber-like shape that abuts on the inner peripheral side of these resin rings and gives expansion force. Two structural members, ie, O-rings 114, 115 and 116 made of an elastic material are provided.
[0005]
8B, 8D and 8F, the shaft hole 101a and the shaft 102 of the housing 101 are coaxially arranged, and the shaft 102 is stopped / rotated / oscillated / reciprocated according to the purpose. Etc. are performed. An annular groove 102b having a rectangular cross section is provided on the outer peripheral surface 102a of the shaft 102, and sealing devices 100A, 100B, and 100C are mounted.
[0006]
The sealing devices 100A and 100B include resin rings 111 and 112 having a rectangular cross section, and the outer peripheral surfaces 111a and 112a of the resin rings 111 and 112 (the outer peripheral wall surfaces of the resin rings when viewed in a cylindrical shape) are shaft holes of the housing 101. It is a sliding surface with 101a.
[0007]
In addition, in the sealing device 100C, the cross-sectional shape of the resin ring 113 is asymmetrical in order to function as a one-side seal that can further prevent fluid from entering from the direction of the arrow A101 in the mounted state.
[0008]
Specifically, it has a cross-sectional shape having an outer peripheral contour in which an inclined surface portion 113a whose outer peripheral surface is reduced in diameter in the direction of arrow A101 and a parallel surface portion 113b having a slightly smaller diameter than the inclined surface portion 113a are connected in the axial direction. (The cross-sectional shape of FIG. 8 highlights the features of the outer peripheral contour, and the actual interval between the inclined surface portion 113a and the parallel surface portion 113b may be set smaller than that shown in the figure).
[0009]
Therefore, the sealing devices 100A, 100B, and 100C having such a configuration give the expansion force to the resin ring having low elasticity by combining the resin ring and the O-ring, and the opposing sliding surface (in FIG. 8, the shaft hole of the housing 101). 101a) is brought into contact with a predetermined pressure to exert a sealing property, and is excellent in slidability / abrasion resistance from the characteristics of the resin material.
[0010]
[Problems to be solved by the invention]
However, in the sealing devices 100A and 100B, since the resin rings 111 and 112 receive the largest expansion force at the substantially central portions in the substantially axial direction by the O-rings 114 and 115, the surface pressure distribution PD100A on the outer peripheral surfaces 111a and 112a. , PD100B has a mountain shape in which the surface pressure gradually increases toward the central portion, and the fluid is more likely to enter from both ends in the axial direction where the surface pressure is low, thus reducing the sealing performance.
[0011]
On the other hand, in the sealing device 100C, a surface pressure distribution PD100C having a steep rise on the side that exerts a pressure resistance (left side in the figure) is formed, which is sufficient for the sealing performance in the direction of the arrow A101. The fluid easily enters from the opposite side (right side in the figure), and the sealing performance is lowered.
[0012]
Further, in the sealing device 100C, since the outer peripheral wall surface is not a flat surface (cylindrical wall surface), the manufacturability is inferior to that of the sealing devices 100A and 100B, and the surface pressure distribution changes due to the wear of the inclined surface portion 113a. There was also concern that this could lead to a decline.
[0013]
The present invention has been made in order to solve the above-described problems of the prior art, and the object is to make it possible to form a surface pressure distribution that exhibits good sealing performance and to exhibit sealing performance in both directions. In other words, the sealing performance of the sealing device is improved with a simple configuration.
[0014]
[Means for Solving the Problems]
In order to achieve the above object, the present invention includes a sliding surface that is fitted into an annular groove formed on one surface of an annular gap formed by two opposing surfaces and abuts against the other surface. The sealing device includes a sealing member, and a biasing member that abuts against the sealing member and biases toward the other surface. The sealing member includes a peripheral wall portion having the sliding surface, and the peripheral wall portion. A pair of flange portions extending in a radial direction from positions separated from each other in the axial direction, and the urging member presses and displaces the pair of flange portions toward the outside, thereby the peripheral wall. It is characterized by being fitted between a pair of flange portions so as to bend the portion .
[0015]
As a result, a surface pressure distribution having two peaks with the peak in the vicinity of the end in the axial direction of the sliding surface is formed. The
[0016]
This surface pressure distribution peak shape has a sharp rise in the axially outer direction and exhibits high sealing performance in both directions. For example, the two fluids can be separated without mixing via a sealing device. it can.
[0019]
In addition, it is preferable that the annular groove is provided with a tapered portion in contact with an end portion of the flange portion of the seal member at a groove bottom portion.
[0020]
As a result, the end of the flange portion comes into contact with the tapered portion, thereby pushing the flange portion up to the other surface side of the two opposing surfaces and increasing the surface pressure near the axial end of the sliding surface to improve sealing performance. To further improve.
[0021]
However, the end of the flange portion also has a taper, and the sliding portion is brought into contact with the tapered portion of the annular groove on the other surface side of the two opposing surfaces from the axial biasing center position by the biasing member. It is possible to prevent the flange portion from functioning as lever means that bends the surface convexly (relative to the other surface of the two opposing surfaces).
[0022]
Moreover, it is also suitable that the flange part of the said sealing member is provided with the protrusion part contact | abutted to the side wall part of the said annular groove.
[0023]
Thereby, the flange part functioning as the lever means can be displaced with the ridge part as a fulcrum, the flange part can be further displaced, and the bending of the sliding surface is reliably formed.
[0024]
Moreover, it is also preferable to provide a groove in a substantially central portion on the sliding surface side of the peripheral wall portion of the seal member.
[0025]
Therefore, the circumferential wall can be easily bent by the groove. Further, by providing a seal ring made of a rubber-like elastic body or a porous (sponge-like) fluid holding member in the groove, the sealing performance can be improved.
[0026]
Further, it is also preferable that the sliding surface of the peripheral wall portion of the seal member is formed as a flat surface before the urging member is fitted between the flange portions.
[0027]
Therefore, the workability of the sliding surface of the peripheral wall portion of the seal member is not deteriorated.
[0028]
It is also preferable that the seal member is made of a resin material and the biasing means is made of a rubber-like elastic material.
[0029]
DETAILED DESCRIPTION OF THE INVENTION
(Embodiment 1)
FIGS. 1-2 is a figure explaining the structure of the sealing device 1 in 1st Embodiment to which this invention is applied. In FIG. 1, the sealing device 1 is fitted in an annular groove 102 b provided in the shaft 102, and seals the annular gap 106 between the shaft hole 101 a of the housing 101 and the outer peripheral surface 102 a of the shaft 102 as two opposing surfaces. It is sectional structure explanatory drawing (the figure cut | disconnected in the axial direction) of the principal part explaining a state.
[0030]
FIG. 2 is a cross-sectional view showing a resin ring 2 formed of a resin material as a sealing member constituting the sealing device 1 and an O-ring 3 formed of a rubber-like elastic material as an urging member. FIG. 2 (a)) is a cross-sectional view (FIG. 2 (b)) showing a state in which an O-ring 3 is fitted into the resin ring 2. FIG.
[0031]
First, the members constituting the sealing device 1 will be described with reference to FIG.
[0032]
The resin ring 2 is a resin material having excellent wear resistance and sliding properties such as PTFE, and the outer peripheral surface of the peripheral wall portion 2a is a sliding surface 2b that comes into contact with and slides on the shaft hole 101a of the housing 101. A pair of flange portions 2c and 2d extending in the radial direction are provided at both axial ends on the inner peripheral side of 2a.
[0033]
A holding groove 2e into which the O-ring 3 is fitted is formed between the flange portions 2c and 2d. The sliding surface 2b is processed as a flat surface before the O-ring 3 is fitted.
[0034]
Further, the O-ring 3 has a circular cross-sectional shape in this embodiment, and the dimension of the diameter W in a single state is such that W> H with respect to the dimension of the width H of the holding groove 2e. Is set. That is, the holding groove 2 e has a margin for the O-ring 3.
[0035]
Then, as shown in FIG. 2B, when the O-ring 3 is fitted into the resin ring 2, the flange portions 2c and 2d are displaced in the directions of the arrows A1 and A2, and function as lever means for bending the peripheral wall portion 2a. . Therefore, the sliding surface 2b of the resin ring 2 is also recessed in the axial direction.
[0036]
Next, a state where the sealing device 1 is fitted in the annular groove 102b and exhibits a sealing function will be described with reference to FIG.
[0037]
The sliding surface 2b of the resin ring 2 is urged against and abutted against the shaft hole 101a by an expansion force generated as a reaction when the O-ring 3 is crushed in the radial direction. Since the sliding surface 2b is recessed in the axial direction, surface pressure distributions PD1 and PD2 having two peaks having a peak near the axial end of the sliding surface are formed.
[0038]
The shape of the peaks of the surface pressure distributions PD1 and PD2 has a steep rise on the outside in the axial direction and exhibits high sealing performance in both directions (for fluids entering from the directions of arrows A3 and A4 in the figure). For example, the two fluids can be separated from each other inside the housing 101 via the sealing device 1.
[0039]
Therefore, it is possible to form a surface pressure distribution that exhibits sealing performance in both directions on the sliding surface 2b with a simple configuration, and to improve the sealing performance of the sealing device.
[0040]
In this embodiment, the sealing device 1 is also annular in order to seal the annular gap 106. However, even when the two opposing surfaces are flat, the annular curvature is set large and a part of the annular is used. Can be applied.
[0041]
(Embodiment 2)
3, 4 and 5 show the sealing device 11 in the second embodiment. 3A, 3B, and 3C are sectional views independently showing the annular groove 102c of the resin ring 12, the O-ring 3, and the shaft 102, respectively, and FIG. 4 shows the sealing device 11 and the annular groove. FIG. 5 is a diagram showing an engagement relationship with 102 c, and FIG. 5 is a diagram showing an operating state of the sealing device 11.
[0042]
In this sealing device 11, tapered portions 102d and 102e that contact the end portions of the flange portions 12c and 12d of the resin ring 12 are formed in the annular groove 102c of the shaft 102 into which the sealing device 11 is fitted, and the groove bottom portion 102f (or the annular groove 102c). Provided in a part of the side wall portions 102g, 102h).
[0043]
Further, the end portions of the flange portions 12c and 12d of the resin ring 12 are provided with tapered portions 12e and 12f which are slanted with respect to the axial direction as compared with the tapered portions 102d and 102e.
[0044]
When the O-ring 3 is fitted into the resin ring 12 and engaged with the annular groove 102c (see FIG. 4), the outer ends 12g and 12h of the taper portions 12e and 12f of the resin ring 12 are tapered portions 102d and 102e. , A stress is generated to push up the flange portions 12c and 12d in the directions of arrows A5 and A6, further bending the peripheral wall portion 12a and causing the sliding surface 12b to be recessed in the axial direction.
[0045]
By adopting such a configuration, as shown in FIG. 5, the peak surface pressures of the surface pressure distributions PD3 and PD4 having two peaks having the peak near the axial end of the sliding surface 12b are increased. Can improve the sealing performance in both directions.
[0046]
The flange portions 12c and 12d serve as lever means for bending the sliding surface 12b in a convex shape because the positions of the end portions 12g and 12h are located on the outer peripheral side with respect to the axial biasing center position by the O-ring 3. It is prevented and it is more preferable.
[0047]
(Embodiment 3)
FIG. 6 is a cross-sectional configuration explanatory view of a sealing device 21 according to the third embodiment. The configurations of the housing 101 and the shaft 102 are the same as those in the first embodiment. Further, regarding the sealing device 21, the same reference numerals are given to the same configurations as those in the first embodiment.
[0048]
The characteristic configuration of the sealing device 21 includes protrusions 22 and 23 that abut against the side walls 102g and 102h of the annular groove 102b on the axially outer side of the pair of flange portions 2c and 2d of the resin ring 2.
[0049]
As a result, the flange portions 2c and 2d functioning as lever means can be displaced with the ridge portions 22 and 23 as fulcrums, the flange portions 2c and 2d can be further displaced, and the bending of the sliding surface 2b is ensured. Is formed.
[0050]
Since other operations and effects are the same as those of the first embodiment, the description thereof is omitted. The protrusions 22 and 23 are positioned on the outer peripheral side of the axial biasing center position of the O-ring 3 so that the flanges 2c and 2d serve as lever means for flexing the sliding surface 2b. Is more preferable because it is prevented from functioning.
[0051]
The protruding cross-sectional shape is not limited to the semicircular cross-section as in this embodiment, and other cross-sectional shapes such as a rectangular cross-sectional shape can be set as appropriate.
[0052]
(Embodiment 4)
FIG. 6 is a cross-sectional configuration explanatory view of a sealing device 31 according to the fourth embodiment. The configurations of the housing 101 and the shaft 102 are the same as those in the first embodiment. Further, regarding the sealing device 31, the same reference numerals are given to the same configurations as those of the first embodiment.
[0053]
The characteristic configuration of the sealing device 31 includes a groove 32 at a substantially central portion of the sliding surface 2 b of the resin ring 2.
[0054]
Therefore, the groove 32 can easily form the deflection of the flange portions 2c and 2d. Further, by providing a seal ring made of a rubber-like elastic body, a porous (sponge-like) fluid holding member, or the like inside the groove 32, it is possible to improve the sealing performance.
[0055]
Since other operations and effects are the same as those of the first embodiment, the description thereof is omitted. The cross-sectional shape of the groove 32 is not limited to the substantially U-shaped cross section as in this embodiment, and an arc cross-sectional shape or a rectangular cross-sectional shape can be set as appropriate.
[0056]
【The invention's effect】
As described above, according to the sealing device to which the present invention is applied, it is possible to form a surface pressure distribution that exhibits a good sealing property on a sliding surface with a simple configuration, and also exhibits a sealing property in both directions. Therefore, the sealing performance of the sealing device can be improved.
[0058]
Since the annular groove is provided with a tapered portion at the groove bottom portion, the end of the flange portion abuts against the tapered portion to push the flange portion toward the other surface side of the two opposing surfaces, and in the vicinity of the axial end portion of the sliding surface. Increase the surface pressure to further improve the sealing performance.
[0059]
By providing the flange portion with the ridge portion that contacts the side wall portion of the annular groove, the flange portion functioning as a lever means can be displaced with the ridge portion as a fulcrum, and the flange portion can be displaced more reliably. The sliding surface is bent.
[0060]
By providing a groove in the substantially central portion on the sliding surface side of the peripheral wall portion of the seal member, the peripheral wall portion can be easily bent and the sealing performance can be further improved.
[Brief description of the drawings]
FIG. 1 is a cross-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 view of a sealing device component according to a second embodiment.
FIG. 4 is a cross-sectional configuration explanatory view of a sealing device according to a second embodiment.
FIG. 5 is a cross-sectional configuration explanatory view of a sealing device according to a second embodiment.
FIG. 6 is a cross-sectional configuration explanatory view of a sealing device according to a third embodiment.
FIG. 7 is a cross-sectional configuration explanatory view of a sealing device according to a fourth embodiment.
FIG. 8 is a diagram showing a surface pressure distribution characteristic of a conventional sealing device and its sliding surface.
[Explanation of symbols]
1 Sealing device 2 Resin ring (seal member)
2a peripheral wall portion 2b sliding surface 2c, 2d flange portion 2e holding groove 3 O-ring 101 housing 101a shaft hole 102 shaft 102a outer peripheral surface 102b annular groove 106 annular gap PD1, PD2 surface pressure distribution

Claims (6)

2 A seal member that is fitted in an annular groove formed on one surface of the annular gap formed by the opposed surfaces and that has a sliding surface that contacts the other surface; A sealing device including a biasing member that biases the surface of
The seal member includes a peripheral wall portion having the sliding surface, and a pair of flange portions extending in a radial direction from positions separated in the axial direction of the peripheral wall portion,
The urging member is fitted between a pair of flange portions so as to bend the peripheral wall portion by pressing and displacing the pair of flange portions outward . 2. The sealing device according to claim 1, wherein the annular groove includes a taper portion in contact with an end portion of the flange portion of the seal member at a groove bottom portion. Flange portion of the sealing member, the sealing device according to claim 1, characterized in that it comprises the abutting ridges on the side wall portion of the annular groove. The sealing device according to claim 1 , wherein a groove is provided in a substantially central portion on the sliding surface side of the peripheral wall portion of the seal member. The sliding surface of the peripheral wall of the sealing member, before said biasing member is fitted between the flange portions, any one of claims 1 to 4, characterized in that it is formed as a flat surface The sealing device according to 1. The sealing member is formed of a resin material, said biasing means sealing device according to any one of claims 1 to 5, characterized in that it is formed of a rubber-like elastic material.

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