JP3893761B2 - Sealing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sealing device that prevents leakage of a sealing fluid, and is used in an environment that is highly eccentric and requires dust resistance and mud water resistance, such as an automobile axle seal. The present invention relates to a sealing device.
[0002]
[Prior art]
Conventionally, as this type of sealing device used in an environment that is highly eccentric and requires dust resistance and mud water resistance, for example, there are those shown in FIG. 5 and those shown in FIG. .
[0003]
5 and 6 are schematic cross-sectional views of a conventional sealing device.
[0004]
In any of the sealing devices shown, the main role is that they are arranged in an annular gap between the shaft and the housing that are concentrically arranged so as to be relatively rotatable. This prevents leakage to the atmosphere side (side opposite to the sealing fluid) A.
[0005]
And in any sealing device, a seal lip that slidably contacts the shaft to prevent fluid leakage, and a dust lip that slidably contacts the shaft to prevent entry of foreign matter from the atmosphere side A, It has.
[0006]
However, the basic configuration of the sealing device, which is simply provided with a seal lip and dust lip, is insufficient in an environment that is highly eccentric and requires dust resistance and mud water resistance. The configuration shown in FIGS. 5 and 6 has the following characteristics.
[0007]
In addition, in each figure, in order to demonstrate easily, the partial sectional view by the sealing device single-piece | unit is shown, and the positional relationship when a sealing device is used (when a sealing device is incorporated) is understood about other members. Thus, only the positional relationship is schematically shown.
[0008]
First, in the sealing device 100 according to the prior art shown in FIG. 5, the above-described seal lip 101 that slidably contacts the surface of the shaft 10 to prevent fluid leakage, and slidable on the surface of the shaft 10. The side lip 103 is provided in addition to the dust lip 102 that prevents the intrusion of foreign matter from the atmosphere side A by contacting the slinger 200 and slidingly contacting the slinger 200.
[0009]
Since the side lip 103 has a large area in sliding contact with the slinger 200, in order to effectively prevent intrusion of fine particles such as muddy water, the intrusion reaching the dust lip 102 is reduced. The damage of the dust lip 102 itself was also reduced, and it was effective even in the severe environment described above.
[0010]
Further, in the sealing device 200 according to the prior art shown in FIG. 6, the above-described seal lip 201 that slidably contacts the surface of the shaft 10 to prevent fluid leakage, and slidable on the surface of the shaft 10. The dust strip 202 is provided to prevent foreign matter from entering from the atmosphere side A in contact with the surface. However, in the sealing device 200, the tightening margin (sliding area) of the dust strip 202 with respect to the surface of the shaft 10 is increased. It is something that I took.
[0011]
Even in such a large tightening allowance, in order to effectively prevent foreign substances from entering even against axial eccentricity and effectively prevent fine particles from entering, It was effective even below.
[0012]
[Problems to be solved by the invention]
However, in the case of the prior art as described above, the following problems have occurred.
[0013]
In the case of the configuration shown in FIG. 5, it is necessary to use a slinger or to change the structure of the mating attachment member in order to seal with the side lip. There was a problem.
[0014]
Further, in the case of the configuration shown in FIG. 6, since the allowance for the surface of the dust lip shaft is large, there is a problem that when the shaft is mounted from the dust lip side, the lip of the dust lip is generated. .
[0015]
Further, in any configuration, the configuration is such that the surface of the mating member is slid so as to have a relatively large sliding area (in the case of FIG. 5, the side lip, in the case of FIG. 6). Because of this, the lip surface was strongly pressed against the mating member surface, increasing the torque.
[0016]
In addition, since it is strongly pressed, it is easy to cause sliding wear and poor wear, leading to an increase in lip heat generation.
[0017]
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 that it is highly eccentric and used in an environment where dust resistance and mud water resistance are required. Even if it exists, it is providing the sealing device excellent in the quality which can contact in a stable state with respect to the shaft surface.
[0018]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a sealing device that includes a seal body having a metal ring and a seal portion fixed to the metal ring, and seals an annular gap between the shaft and the housing. A bellows portion extending from the end opposite to the sealing fluid in the metal ring toward the sealing fluid side and following the eccentricity of the shaft; and extending from the bellows portion toward the sealing fluid side to the shaft A seal lip that slidably contacts the surface and seals fluid leakage, and extends from the bellows to the opposite side of the sealed fluid and slidably contacts the shaft surface to prevent foreign matter from entering the fluid side. a dust lip for preventing, said seal body having, disposed on the shaft periphery, the distance to the shaft surface of the seal lip, and the sealing lip and dust so as to position the distance to the shaft surface of the dust lip A positioning ring that supports the root of the cup, a bellows guide part that suppresses deformation of a predetermined amount or more to the opposite side of the sealing fluid of the bellows part, and a sealing fluid that is disposed on the opposite side of the dust strip. the a dust lip guide unit to suppress the predetermined amount or more eccentric axis with dust cover strip, the possess integrally, the position of the connecting portion of bellows part guide portion and the dust lip guide portion base of the bellows portion Te And a guide ring fitted into the seal body .
[0021]
Therefore, even if the bellows portion follows the shaft eccentricity, the distance from the seal lip and the shaft surface of the dust lip is maintained by the positioning ring, so that stable sealing performance is maintained.
[0023]
Even when the bellows part is deformed by the pressure of the fluid, the deformation is suppressed by the bellows guide part of the guide ring, so that the seal lip and dust lip can maintain a stable sealing effect, and the guide ring The dust strip guide part suppresses the eccentricity of the shaft more than a predetermined amount, so that the dust lip is prevented from being reversed when the shaft is assembled, and the dust lip guide part covers the dust lip. Protected.
[0024]
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, relative arrangements, etc. of the components described in this embodiment are not intended to limit the scope of the present invention only to those unless otherwise specified. Absent.
[0025]
(First embodiment)
With reference to FIGS. 1-3, the sealing device which concerns on the 1st Embodiment of this invention is demonstrated.
[0026]
FIG. 1 is a schematic cross-sectional view of a sealing device according to a first embodiment of the present invention, and FIGS. 2 and 3 are operation explanatory views of the sealing device according to the first embodiment of the present invention.
[0027]
In addition, in each figure, in order to demonstrate easily, the partial cross section figure by the sealing device single-piece | unit is shown, When the sealing device is used about other members (shaft and housing) (when the sealing device is incorporated) Only the positional relationship is schematically shown so that the positional relationship can be understood.
[0028]
The main role of the sealing device 1 is that it is disposed in an annular gap between the shaft 10 and the housing 20 that are concentrically and relatively rotatable, so that fluid (oil, etc.) can flow from the sealed fluid side O to the atmosphere. This prevents leakage to the side (opposite to the sealing fluid) A.
[0029]
Here, the sealing device 1 is generally composed of a seal body having a metal ring 2 and a seal portion 3 fixed to the metal ring 2 by baking, a positioning ring 4 and a guide ring 5.
[0030]
The seal portion 3 includes an outer peripheral seal portion 31, a bellows portion 32, a seal lip 33, and a dust lip 34.
[0031]
The outer peripheral seal portion 31 is in close contact with the housing 20 and seals the outer periphery of the annular gap.
[0032]
The bellows portion 32 is deformed following the shaft eccentricity so that the seal function is properly maintained even when the shaft 10 is decentered with respect to the housing 20, and the seal lip 33 and the dust lip 34 are properly disposed with respect to the shaft 10. It is made to adhere to.
[0033]
The seal lip 33 extends from the bellows portion 32 toward the sealed fluid side O and slidably comes into contact with the surface of the shaft 10 to prevent fluid (oil etc.) from leaking to the outside (atmosphere side A). It fulfills its function.
[0034]
The dust lip 34 extends from the bellows portion 32 toward the atmosphere side A and slidably comes into contact with the surface of the shaft 10 to prevent foreign matter from entering the inside (sealed fluid side O) from the outside. It is.
[0035]
The spring 6 imparts a pressing force to the seal lip 33 in order to properly seal against the surface of the shaft 10.
[0036]
The positioning ring 4, which is a feature of the present embodiment, is arranged so that its inner periphery is slidable with respect to the surface of the shaft 10, and its outer periphery is near the lip root of each of the seal lip 33 and the dust lip 34. It arrange | positions so that it may fit in the provided groove | channel 35. FIG.
[0037]
The material of the positioning ring 4 is made of a resin having a low friction coefficient, so that an increase in torque and an increase in heat generation can be suppressed.
[0038]
Needless to say, the positioning ring 4 has such a hardness that it is not deformed when the shaft is eccentric.
[0039]
The positioning ring 4 supports the lip roots of the seal lip 33 and the dust lip 34 in a direction perpendicular to the axis, so that the distance from the axis surface of each lip is positioned.
[0040]
Therefore, as shown in FIG. 2, when the shaft 10 is decentered in a direction relatively away from the seal body, or as shown in FIG. 3, the shaft 10 is relatively closer to the seal body. Even when the lip is eccentric, the distance of each lip to the shaft surface is kept constant, so that the contact state of each lip with the shaft surface is stable and the sealing function is maintained.
[0041]
Further, since the contact state of the lip can be stabilized, it is not necessary to slide the lip so as to have a relatively wide sliding area as in the prior art, so that an increase in torque and an increase in heat generation can be suppressed.
[0042]
Next, the guide ring 5, which is a feature of the present embodiment, is arranged so as to cover the bellows portion 32 and the atmosphere side A of the dust lip 34.
[0043]
As an assembly order, the shaft 10 is assembled after the guide ring 5 is assembled into the seal body.
[0044]
The guide ring 5 has a bellows guide part 51 and a dust strip guide part 52.
[0045]
The bellows guide part 51 functions to prevent deformation of the bellows part 32 by a predetermined amount or more. When the fluid pressure on the sealed fluid side O increases, the bellows part 32 moves to the atmosphere side A. In addition, since the bellows portion guide portion 51 supports, deformation of the bellows portion 32 is suppressed.
[0046]
Therefore, the seal lip 33 and the dust lip 34 are also prevented from moving and deforming in the axial direction and the like, and the sealing function is stabilized.
[0047]
The dust lip guide portion 52 covers the dust lip 34 to a position where it enters the dust lip 34 by a predetermined amount (h in FIG. 1).
[0048]
Therefore, at the time of incorporation, the function of preventing the inversion of the dust lip 34 is exhibited by suppressing the eccentricity of the shaft 10.
[0049]
Further, in the state of use, the dust lip 34 is covered, so that the foreign matter directly hits the dust lip 34 from the outside.
[0050]
As described above, the positioning ring 4 can stabilize the contact state of the seal lip 33 and the dust lip 34 with the shaft surface, and the guide ring 5 prevents the bellows portion 32 from being deformed. Since the inversion is prevented and the dust lip 34 is protected, the sealing performance (sealing performance) is improved.
[0051]
(Second Embodiment)
FIG. 4 shows a second embodiment of the present invention. In the present embodiment, only the configuration (shape) of the positioning ring is different from the above-described embodiment.
[0052]
Since other configurations and operations are the same as those of the first embodiment, the same components are denoted by the same reference numerals and description thereof is omitted.
[0053]
FIG. 4 is a schematic cross-sectional view of a sealing device according to the second embodiment of the present invention.
[0054]
In the present embodiment, the positioning ring 4 a is provided with an auxiliary support portion 41 extending to the sealing fluid side O along the lip surface of the seal lip 33, so that the deformation of the seal lip 33 can be further suppressed.
[0055]
Therefore, even when the fluid on the sealed fluid side O becomes high pressure, deformation of the seal lip 33 to the atmosphere side A can be suppressed and the sealing performance can be maintained, so it is effective when used at high pressure. It is.
[0056]
【The invention's effect】
As described above, the present invention includes a positioning ring that supports the root of the seal lip so as to position the distance from the shaft surface of the seal lip. Because the positioning ring can maintain the distance from the shaft surface of the seal lip or dust lip, stable sealing performance can be maintained, and it was used in environments where high eccentricity, dust resistance and mud water resistance are required. Even in this case, it is possible to contact the shaft surface in a stable state, and the quality is improved.
[0057]
In addition, by providing a guide ring, even if the bellows part is deformed by the pressure of the fluid, the bellows guide part of the guide ring suppresses the deformation, so that the seal lip and dust lip maintain a stable sealing effect. In addition, since the dust ring guide portion of the guide ring suppresses eccentricity of a predetermined amount or more of the shaft, the dust strip can be prevented from being inverted when the shaft is assembled, and the dust strip guide portion covers the dust strip. The strip can be protected from foreign substances and a stable sealing effect can be maintained.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of a sealing device according to a first embodiment of the present invention.
FIG. 2 is an operation explanatory view of the sealing device according to the first embodiment of the present invention.
FIG. 3 is an operation explanatory view of the sealing device according to the first embodiment of the present invention.
FIG. 4 is a schematic sectional view of a sealing device according to a second embodiment of the present invention.
FIG. 5 is a schematic cross-sectional view of a conventional sealing device.
FIG. 6 is a schematic cross-sectional view of a conventional sealing device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Sealing device 2 Metal ring 3 Seal part 31 Outer periphery seal part 32 Bellow part 33 Seal lip 34 Dustrip 35 Grooves 4 and 4a Positioning ring 41 Auxiliary support part 5 Guide ring 51 Bellow part guide part 52 Dustrip guide part 6 Spring 10 Shaft 20 Housing

Claims (1)

In a sealing device comprising a seal body having a metal ring and a seal portion fixed to the metal ring, and sealing an annular gap between the shaft and the housing,
A bellows portion extending from the end opposite to the sealing fluid in the metal ring toward the sealing fluid side and following the eccentricity of the shaft; and extending from the bellows toward the sealing fluid side to the shaft surface A seal lip that slidably contacts to seal the leakage of fluid, and extends from the bellows to the opposite side of the sealed fluid and slidably contacts the shaft surface to prevent foreign matter from entering the fluid side. a dust lip which, said seal body having,
A positioning ring disposed on the outer periphery of the shaft for supporting the seal lip and the base of the dust lip so as to position the distance to the shaft surface of the seal lip and the distance to the shaft surface of the dust lip;
A bellows guide portion that suppresses deformation of a predetermined amount or more to the opposite side of the bellows portion from the sealing fluid, and a bellows portion guide portion that is disposed on the opposite side of the dusting fluid to cover the dustlip and a predetermined amount of the shaft. integrally closed and a dust lip guide unit to suppress the eccentricity of the above, the guide ring connecting parts of these bellows portion guide portion and the dust lip guide portion is fitted in the seal body at the location of the root of the bellows portion When,
A sealing device comprising:

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