JP4193299B2 - Sealing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sealing device used for a shaft seal portion of various devices, and more particularly to a sealing device in which two sealing members are combined.
[0002]
[Prior art]
FIG. 3 is a diagram illustrating a cross-sectional configuration of a sealing device 101 including a rubber lip 102 and a resin lip 103 according to the prior art.
[0003]
The schematic configuration of the sealing device 101 will be described. A rubber lip 102, a resin lip 103, and a dust lip 104 are fitted into an annular member 110 having a groove portion 111 that holds an O-ring 112 on the outer peripheral surface. The radial direction portion 113 and the caulking portion 114 at the end of the annular member 110 are fixed in a stacked manner.
[0004]
Prior to assembly of the sealing device 101, the rubber lip 102 and the dust lip 104 are integrated with the metal reinforcing rings 102a and 104a in advance by vulcanization molding or the like. The resin lip 103 is of a flat washer shape made of PTFE, and a cylindrical jig having substantially the same outer diameter as that of the shaft to be inserted after assembly is inserted to expand the inner diameter portion, and the sealing side M It is bent toward
[0005]
Reference numeral 201 denotes a housing member that fixes the sealing device 101, and 202 denotes a shaft that is fitted into the housing member 201. In this figure, the shaft is drawn by an imaginary line.
[0006]
The sealing device 101 includes a rubber lip 102 on the sealing side M and a resin lip 103 on the atmosphere side O connected to the rubber lip 102 in order to prevent leakage of the sealing fluid on the sealing side M, which is particularly high pressure. ing.
[0007]
The rubber lip 102 exhibits a sealing property due to a pressing force against the sliding surface 203 (the outer peripheral surface of the shaft 202) at the lip tip.
[0008]
Further, when the rubber lip 102 is deformed by the pressure on the sealing side M, a metal support member 107 is provided which contacts the lower surface of the rubber lip 102 and suppresses excessive deformation of the rubber lip 102.
[0009]
In addition, the resin lip 103 is formed with a thread groove 108 and prevents the leakage of the sealing fluid by acting as a fluid pump that moves the sealing fluid slightly leaked in the contact area with the sliding surface 203 by the rotation of the shaft 202. is doing.
[0010]
[Problems to be solved by the invention]
However, in the conventional sealing device as described above, since the pressure of the sealing fluid is received by the rubber lip 102, when the pressure of the sealing fluid becomes high, the deformation of the rubber lip 102 due to high pressure and excessive surface pressure due to the deformation. As a result, wear proceeds and leakage occurs.
[0011]
The present invention has been made in order to solve the above-described problems of the prior art, and the object of the present invention is to provide a highly reliable sealing device with improved pressure resistance and improved sealing performance and durability. It is to provide.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, the present invention seals an annular gap between a shaft hole of a housing and a shaft rotatably provided in the shaft hole, and is fitted and fixed to the shaft. A first annular member having one radial portion and a shaft hole inner peripheral surface of the housing are fitted and fixed, and opposed to the first radial portion on the non-sealing side from the first radial portion. a sealing apparatus provided with a second annular member having a second radial portion, provided on an outer peripheral side of said first annular member, between the shaft hole and the first annular member of the housing A plurality of projections provided on at least one of the first and second radial portions and sealing the opposing gap between the first and second radial portions. And a sealing lip having a shape.
[0013]
According to this configuration, the pressure applied to the sealing device by the seal member is reduced, and the reduced pressure is applied to the multi-stage projecting seal lip, so that it is not deformed and worn by the high pressure, and has a sealing property and durability. Can be improved.
[0014]
Also, by providing a plurality of protruding seal lips that seal the opposing gaps between the first and second radial portions, the pressure difference between the seal lips can be reduced, and deformation of the seal lip is prevented. be able to.
[0015]
Furthermore, by providing a plurality of stages of seal lips in the first radial direction portion, fluid leaking from the seal member to the seal lip can be returned radially outward by the action of centrifugal force accompanying the rotation of the shaft. The sealing performance of the seal lip can be improved.
[0016]
Further, the seal member is made of resin material, and seals an annular gap between the housing and the shaft in the axial direction,
It is also preferable that the plurality of stages of sealing lips are made of a rubber-like elastic material and seal an annular gap between the housing and the shaft in a radial direction.
[0017]
As a result, the pressure applied in the axial direction is reduced and sealed with a seal member having small sliding resistance and deformation, and then the radial direction is sealed with a plurality of stages of rubber-like elastic material, so that the sealing performance can be improved.
[0018]
It is also preferable to include holding means for holding a gap between the first and second radial portions facing each other at a predetermined interval.
[0019]
Thereby, the pressure receiving area of the seal lip can be reduced, and deformation of the lip can be reduced.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Exemplary embodiments of the present invention will be described in detail below with reference to the drawings. However, the dimensions, materials, shapes, and relative arrangements of the components described in this embodiment should be appropriately changed according to the configuration of the apparatus to which the invention is applied and various conditions. It is not intended to limit the scope to the following embodiments.
[0021]
A sealing device according to an embodiment of the present invention is shown in FIGS. The sealing device 10 according to the present embodiment seals an annular gap between the shaft 1 and the housing 2 having a cylindrical opening, and fluid such as oil or gas on the sealed side M is air side O (non-sealed). Side).
[0022]
The sealing device 10 generally includes a decompression seal unit 5 as a first annular member, a sleeve 4 as a second annular member, and a plurality of projecting seals provided between the decompression seal unit 5 and the sleeve 4. It is comprised from the end surface lip 3 as a lip.
[0023]
The decompression seal unit 5 includes a body 9 having a substantially H-shaped cross section having recesses at both ends and is fitted and fixed to the shaft 1 with one recess facing the shaft 1, and rotates integrally with the shaft 1. The body 9 is formed of a rigid metal or resin that does not deform the recess even when high pressure is applied. A stopper 8 is provided on the atmosphere side O of the body 9 of the shaft 1.
[0024]
An O-ring 7 is fitted in the recess on the shaft 1 side of the body 9, and a slipper seal 6 as a seal member made of a combination of a rubber ring and an ethylene tetrafluoride resin ring is fitted in the recess on the housing 2 side, A tetrafluoroethylene resin as a resin material is slidably in contact with the housing 2.
[0025]
A sleeve 4 is fitted and fixed to the inner peripheral surface of the shaft hole of the housing 2 on the atmosphere side O of the decompression seal unit 5. The sleeve 4 is made of metal such as iron or resin.
[0026]
A rubber-like elastic material is provided between the radial end surface 5a (first radial direction portion) on the atmosphere side O of the decompression seal unit 5 and the radial end surface 4a (second radial direction portion) on the sealing side M of the sleeve 4. A plurality of protruding end face lips 3 are provided.
[0027]
The end face lip 3 is integrally baked on at least one of the pressure-reducing seal unit 5 and the sleeve 4 and is provided so as to seal the fluid from the outermost side to the inner side of the annular gap. FIG. 1 shows a state where the sleeve 4 is provided, and FIG. 2 shows a state where the pressure reducing seal unit 5 and the sleeve 4 are alternately provided.
[0028]
By the sealing device 10 configured as described above, the sealing fluid on the sealing side M is sealed in the axial direction by the slipper seal 6 of the decompression seal unit 5, and the fluid leaking from the slipper seal 6 is removed from the decompression seal unit 5 and the sleeve. The end face lip 3 between 4 is sealed in the radial direction.
[0029]
When the pressure of the sealing fluid on the sealing side M is high, the fluid leaks from the slipper seal 6. However, since the leaked fluid is decompressed at the end face lip 3, deformation of the end face lip 3 due to the fluid can be reduced, and a plurality of stages The protrusion-like end lip 3 is securely sealed. It is preferable that the protruding lip tip of the end face lip 3 is disposed radially outward as shown in FIG.
[0030]
Furthermore, since the end surface lip 3 seals the fluid flowing from the outside to the inside of the annular gap, if at least one end surface lip 3 is provided in the decompression seal unit 5, due to the action of centrifugal force accompanying the rotation of the shaft 1, The fluid leaking from the slipper seal 6 to the end face lips 3 in a plurality of stages can be returned to the outside in the radial direction, and the sealing performance of the end face lip 3 can be improved.
[0031]
Moreover, since the pressure difference between lips can be reduced by setting as many end surface lips 3 as possible, the deformation of the lips can be reduced, and the sealing performance and durability can be improved.
[0032]
Further, the stopper 8 and the stopper (not shown) provided on the housing 2 side as the holding means can set the interval between the decompression seal unit 5 and the sleeve 4 to a predetermined interval, and a stable sealing property can be obtained. Furthermore, since the pressure receiving area of the end surface lip 3 can be reduced by setting the interval small, the deformation of the lip can be further reduced, and the sealing performance and durability can be improved.
[0033]
Here, the holding means may be stoppers (not shown) provided in the circumferential direction of the radial end faces 4a, 5a provided with the end face lip 3, or when the sleeve 4 and the body 9 are configured to be fitted. May be the fitting part.
[0034]
When fluid leaks from the decompression seal unit 5 and accumulates pressure between the decompression seal unit 5 and the sleeve 4, as shown in FIG. 1, a taper portion is provided on the sliding surface of the slipper seal 6, and this taper portion Is set to the sealed side, the pressure accumulation between the vacuum seal unit 5 and the sleeve 4 can be released.
[0035]
【The invention's effect】
As described above, according to the present invention, the seal member that seals the gap between the first annular member and the housing or the second annular member, and the opposing gap between the first and second radial portions are provided. By providing a multi-stage protruding seal lip for sealing, the pressure applied to the sealing device by the sealing member is reduced, and the reduced pressure is applied to the multi-stage protruding seal lip. Therefore, it is possible to provide a highly reliable sealing device that can prevent deformation and wear, has excellent pressure resistance, and has improved sealing performance and durability.
[0036]
Also, by providing a plurality of protruding seal lips that seal the opposing gaps between the first and second radial portions, the pressure difference between the seal lips can be reduced, and deformation of the seal lip is prevented. be able to.
[0037]
Furthermore, by providing a plurality of stages of seal lips in the first radial direction portion, fluid leaking from the seal member to the seal lip can be returned radially outward by the action of centrifugal force accompanying the rotation of the shaft. The sealing performance of the seal lip can be improved.
[0038]
Moreover, since the pressure receiving area of the seal lip can be reduced by providing the holding means for holding the gap between the first and second radial portions at a predetermined interval, deformation of the lip can be reduced. It is possible to improve sealing performance and durability.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view of a sealing device according to an embodiment of the present invention.
FIG. 2 is a schematic cross-sectional view for explaining a main part of the sealing device according to the embodiment of the present invention.
FIG. 3 is a schematic sectional view of a conventional sealing device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Shaft 2 Housing 3 End surface lip 4 Sleeve 4a, 5a Radial end surface 5 Pressure reduction seal unit 6 Slipper seal 7 O-ring 8 Stopper 9 Body 10 Sealing device

Claims (4)

Sealing the annular gap between the shaft hole of the housing and the shaft rotatably provided in the shaft hole,
A first annular member fitted and fixed to the shaft and having a first radial portion;
A second annular member fitted and fixed to the inner peripheral surface of the shaft hole of the housing , and having a second radial portion opposed to the first radial portion on the non-sealing side from the first radial portion ; ,
In a sealing device comprising:
A seal member that is provided on the outer peripheral side of the first annular member and seals a gap between the shaft hole of the housing and the first annular member;
A plurality of projecting seal lips provided on at least one of the first and second radial portions and sealing a gap between the first and second radial portions facing each other. A sealing device characterized by. The seal member is made of resin material, and seals an annular gap between the housing and the shaft in the axial direction.
The sealing device according to claim 1, wherein the plurality of stages of sealing lips are made of a rubber-like elastic material, and seal an annular gap between the housing and the shaft in a radial direction.   The sealing device according to claim 1, further comprising a holding unit that holds a gap between the first and second radial portions facing each other at a predetermined interval.   4. The sealing device according to claim 1, wherein a tip of each of the plurality of stages of projecting seal lips is provided radially outward. 5.

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