JP3493888B2 - Sealing device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing device including an oil seal and a bearing, which has a characteristic structure in an engaging portion between the oil seal and the bearing.

[0002]

2. Description of the Related Art A conventional sealing device of this type is shown in FIG. 3, for example. This sealing device 100 is provided with a housing 101 by an oil seal 103 made of a rubber-like elastic material fixed to an inner peripheral portion of the housing 101, and a bearing 104 arranged on the non-sealing side (atmosphere side O) of the oil seal 103. The gap between the sliding shafts 102 is sealed.

Specifically, for example, when the shaft 102 is a power steering rod of an automobile or the like, a high pressure of a fluid (power steering oil in this application example) sealed in the sealed side M is used. Needs to be applied to the oil seal 103 while the pressure fluctuates, and at the same time, it is necessary to maintain stable sealing performance in a state where the shaft 102 reciprocates for a long period.

The oil seal 103 has a fitting portion 103a at its outer peripheral portion, and is fitted and fixed to the inner peripheral portion of the housing 101 by utilizing the high elasticity of the rubber-like elastic material. Further, 103b is a seal lip portion that comes into contact with the sliding surface of the shaft 102, and a tense force is applied by a spring 103c. 103d is a radial portion that connects the fitting portion 103a and the seal lip portion 103b.

The bearing 104 is fitted on the inner peripheral portion of the housing 101 and is fixed to the housing 101 by a retaining ring 105. The inner peripheral side of the bearing 104 is the shaft 102.
, But does not impede the movement of the shaft 102.

The sealed side M of the bearing 104 is the oil seal 10.
3 is an engaging portion. 104a is a backup portion that abuts on the seal lip portion 103b to support the seal lip portion 103b from moving or returning due to high pressure applied from the sealing side M.

104b is an oil seal 103 and a bearing 10.
4 is an engaging portion that connects 4 and 4 in the axial direction, and the oil seal 1
03 is a hooking portion 103e that is hooked with this hooking portion 104b.
Are formed.

Therefore, even if the fluid pressure from the sealing side M is applied to the seal lip portion 103b, the seal lip portion 103b
The movement and deformation of b are suppressed and the hermeticity is maintained.

Further, at the time of handling before assembling the sealing device 100, the engaging portion 103e and the engaging portion 104b are handled.
Are in a state of being engaged.

[0010]

However, in such a conventional technique, since the fitting portion 103a of the oil seal 103 maintains the adhesiveness due to the rubber elasticity, the engaging portion 104a of the bearing 104 and the housing 101. Although the mating part 103a is sandwiched between the inner peripheral part of the oil seal 103a and the inner peripheral part thereof, when the wall thickness is large due to the engaging part 103e or the like, the oil seal 103 contracts or is hardened due to hardening due to long-term use. Tend to affect the adhesion.

Therefore, the oil seal 103 may move during use or the sealing performance at the fitting portion may deteriorate. However, if the fit margin is increased in order to obtain a strong adhesion at the fitting portion, the assemblability is deteriorated.

Further, although the backup portion 104a prevents the seal lip portion 103b from moving toward the atmosphere side O, when the shaft 102 moves toward the sealing side M, the radial portion 103d is bent to seal the seal lip portion. The 103b may be dragged and moved to the sealing side M, and stable sealing performance may be impaired.

Further, before the assembling of the sealing device 100, the engaging portion 103e and the engaging portion 104b are easily disengaged during the handling, and there is a possibility that the engaging property must be reengaged at the time of assembling and the assembling property is deteriorated. However, if the depth of each of the engaging portions 103e and 104b is increased in order to achieve a strong engaging state, the engaging portion 103 of the oil seal 103 is increased.
e is liable to cause cracking defects in the part during molding,
There is a risk of reducing manufacturing efficiency.

The present invention has been made to solve the above-mentioned problems of the prior art, and its purpose is to prevent movement of the mounted sealing device and deterioration of sealing performance.
It is intended to stabilize the seal lip portion when the sealing device is used and to improve the assembling property.

[0015]

In order to achieve the above object, in the sealing device of the present invention, a cylindrical fitting portion fitted to the inner peripheral portion of the housing and a seal contacting the sliding surface of the shaft. An oil seal having a lip portion, a radial portion connecting the fitting portion and the seal lip portion, and an engagement end portion engaging with the oil seal at one end portion thereof; A sealing device comprising a bearing fixed to a peripheral portion, wherein a radial direction portion of the oil seal is provided with a first tubular protrusion portion facing the fitting portion via a groove portion, and the bearing is provided. Has a second tubular protrusion that is fitted and inserted into the groove of the oil seal, and a third tubular protrusion that fits inside the first tubular protrusion of the oil seal. And a protrusion.

According to this, when the sealing device is mounted on the inner peripheral portion of the housing, the fitting portion of the oil seal receives a high compressive force by the second cylindrical protruding portion of the bearing, and the inner peripheral portion of the housing is subjected to the high compressive force. Since it is firmly crimped, it does not move easily and the sealing property is maintained.

The radial portion of the oil seal is axially movable because the first tubular projection portion provided on the radial portion is clamped by the second and third tubular projection portions of the bearing. As a result, the behavior of the seal lip portion is stabilized, and detachment in the state where the oil seal and the bearing are combined is prevented.

It is also preferable that the third cylindrical protrusion of the bearing is provided with a backup portion that abuts on the seal lip portion and suppresses movement of the seal lip portion.

According to this, the backup portion prevents the seal lip portion from moving or falling toward the bearing side, and the movement or falling of the seal lip portion in the direction opposite to the bearing side is caused by the first cylindrical protruding portion of the bearing. It is suppressed by being sandwiched by the second and third cylindrical protrusions.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below based on the illustrated embodiments. FIG. 1 is a diagram showing, as an example, a usage pattern of a sealing device S1 to which the present invention is applied. The sealing device S1 seals a gap between the housing 1 and the shaft 2 and also functions as a bearing for keeping the shaft 2 concentric with the housing.

The sealing device S1 comprises an oil seal 3 made of a rubber-like elastic material fixed to the inner peripheral portion of the housing 1, and a bearing 4 arranged on the non-sealing side (atmosphere side O) of the oil seal 3. Has been done.

The outer periphery of the oil seal 3 is a fitting portion 3
a, which is fitted and fixed to the inner peripheral portion of the housing 1 by utilizing the high elasticity of the rubber-like elastic material, and the fitting portion 3a.
It exhibits a good sealing property. Further, 3b is a seal lip portion that comes into contact with the sliding surface of the shaft 2, and a tightening force is applied by a spring 3c. 3d is a fitting portion 3a
It is a radial portion that connects the seal lip portion 3b with the seal lip portion 3b.

A first cylindrical protrusion 3f is formed on the radial portion 3d so as to face the fitting portion 3a via the concave groove portion 3e.

The bearing 4 is fitted on the inner peripheral portion of the housing 1 and is fixed to the housing 1 by a retaining ring 5. The inner peripheral side of the bearing 4 is a sliding surface that holds the position of the shaft 2.

The sealing side M of the bearing 4 is the oil seal 3
It is an engaging end portion with. The engagement end portion has a second tubular projection portion 4a which is fitted and inserted into the concave groove portion 3e of the oil seal 3, and a third tubular projection portion 3f which is fitted inside the first tubular projection portion 3f of the oil seal 3. The cylindrical protrusions 4b are formed concentrically. Further, the tip of the third tubular protrusion 4b contacts the atmosphere side O of the seal lip 3b, and the seal lip 3b does not move or return due to the high pressure applied from the sealing side M. The backup unit 4c that supports the above is provided.

FIG. 2 is a diagram for explaining the shape of the oil seal 3 in detail. In this figure, the contour of the oil seal 3 shows a state in which it is not deformed by the housing 1, the bearing 4, and the like.

Fitting ridges 3g and 3h for closely contacting the inner peripheral portion of the housing 1 are formed on the outer peripheral portion of the fitting portion 3a at both axial ends. 3i is the second of the bearing 4
Of the cylindrical projection 4a of the bearing 4 which is compressed when the cylindrical projection 4a of FIG.
It is a fitting ridge that is compressed when b is fitted. These fitting ridges may be provided by appropriately setting their shapes and forming positions so that they are firmly fixed when the oil seal 3 and the bearing 4 are combined. Incidentally, it is also possible to form a concave groove in the second and third cylindrical protrusions on the bearing 4 side in correspondence with the protrusion of the fitting protrusion.

In the sealing device S1 having such a structure, when the sealing device S1 is mounted on the inner peripheral portion of the housing 1, the fitting portion 3a of the oil seal 3 is the second cylindrical projection of the bearing 2. The housing 1 receives a high compression force by the portion 4a.
Since it is firmly pressure-bonded to the inner peripheral part of it, it does not move easily and the sealing property is maintained. This is because the thickness of the fitting portion 3a in the radial direction is reduced by the second cylindrical protrusion 4a, the deformation volume ratio is increased, and the compression force is increased.

Further, the radial portion 3d of the oil seal 3
The first tubular projection 3f provided on the radial portion 3d is sandwiched between the second and third tubular projections 4a and 4b of the bearing 4 , so that axial movement is suppressed and the seal The behavior of the lip portion 3b is stabilized, and the lip seal 3b is prevented from coming off when the oil seal 3 and the bearing 4 are combined.

In addition, the third cylindrical protrusion 4 of the bearing 4
Since b has a backup portion 4c that abuts on the seal lip portion 3b and suppresses the movement of the seal lip portion 3b, the backup portion 4c prevents the seal lip portion 3b from moving.
Moved and falling of the bearing 4 side to prevent the seal lip portion 3b movement and tilting of the bearing 4 side to the opposite direction of the second and third tubular first cylindrical protrusion 3f is bearing 4 Protrusion 4a,
Since it is suppressed by being sandwiched by 4b, the behavior of the seal lip portion 3b becomes stable.

[0031]

According to the present invention described in the above embodiment, since the adhesion of the fitting portion of the oil seal is improved, the oil seal is hard to move from the mounting position and is stably mounted, and the fitting portion is It is possible to prevent the deterioration of the sealing property.

Even if the seal lip portion receives an axial force due to the pressure from the sealing side or the reciprocating movement of the shaft 2, the backup lip and the first cylindrical protrusion prevent the seal lip from moving and falling, thus providing a stable seal. Sex is retained.

In the state where the oil seal and the bearing are combined with each other, it is difficult to dislocate, and the handleability at the time of assembly and the assemblability are improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional configuration explanatory diagram of a sealing device according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional explanatory view of an oil seal.

FIG. 3 is a cross-sectional configuration diagram of a conventional sealing device.

[Explanation of symbols]

1 housing 2 axes 3 oil seal 3a Fitting part 3b Seal lip 3c spring 3d radial part 3e concave groove 3f First tubular protrusion 3g, 3h, 3i mating ridge 4 bearings 4a Second cylindrical protrusion 4b Third cylindrical protrusion 4c Backup department 5 retaining ring M sealed side O atmosphere side S1 sealing device

Claims (3)

(57) [Claims] And 1. A tubular fitting portion fitted to the inner peripheral portion of the housing, and a seal lip portion for contacting a sliding surface of the shaft to be reciprocating, and the said mating seal lip A sealing device comprising: an oil seal having a connecting radial portion; and a bearing having an engaging end engaging with the oil seal at one end and fixed to an inner peripheral portion of the housing. Along the radial direction of the oil seal along the direction of the shaft
Opposes the fitting portion via an open groove portion ,
A first cylindrical protrusion extending along the direction of the shaft , wherein the engagement end of the bearing is fitted and inserted into the groove of the oil seal .
A second cylindrical protrusion along the direction and the inside of the first cylindrical protrusion of the oil seal.
Along with the seal lip part, the seal lip
Of the shaft, which has a backup part for suppressing the movement of the part.
And a third tubular protrusion along the direction . 2. The housing is provided on an outer peripheral portion of the fitting portion.
At least one mating ridge that contacts the inner circumference of the ring
Sealing device according to claim 1, characterized in that it is. 3. The second part is provided on the inner peripheral side of the fitting part.
A fitting ridge is formed that is compressed by fitting with the cylindrical protrusion.
In addition, on the inner peripheral side of the first cylindrical protrusion
Fitting projection that is compressed by fitting with the third tubular projection
The dense seal according to claim 1, characterized in that a strip is formed.
Sealing device.