JPH11344121A - Sealing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain the sealability and to improve the durability by preventing the intrusion of foreign matters such as dust by mounting a lip portion contacting the other surface, on an axial end of a sealing member. SOLUTION: A resin ring 5 (sealing member) is made of a PTFE material, its inner peripheral side acts as a sliding surface 5a contacted with an outer peripheral surface 3a of a shaft 3, and its outer peripheral side acts as a pressure receiving surface 5b receiving the energization force of an energizing ring 6. A lip portion 5c contacted with the outer peripheral surface 3a for exercising the sealability is integrally mounted on an axial end of an atmospheric air side A from which the dust or the like is intruded. An axial length of the resin ring 5 is determined so that a point 5d of the lip is projected from an annular groove 2b of the atmospheric air side A in a condition that an end 5h is contacted with the annular groove 2b of a bearing side B, and a lip surface 5e is contacted with a corner 2c of the annular groove 2b to push the lip portion 5c down. As a sealing device 1 is formed by combining the resin ring 5 and the energizing ring 6, the energizing ring 6 is energized to the resin ring 5, and a sliding surface 5a of the resin ring 5 is slidably closely contacted with the outer peripheral surface 3a of the shaft 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing device of a combination type comprising a sealing member and a biasing member fitted in an annular groove, and relates to a technique for improving sealing performance by providing a sealing member with a lip.

[0002]

2. Description of the Related Art Conventionally, various types of dust seals have been employed to prevent foreign substances such as dust from entering a bearing portion of a roller guide.

FIG. 3 shows a bearing 1 of a roller guide 100.
01 is a view for explaining the cross-sectional structure of the roller guide 10;
The zero end shaft 102 is rotatably supported by a mounting housing 104 via a bearing 103.

The mounting housing 104 is provided with a surface 104a facing the end shaft 102 on the roller 105 side of the roller guide 100, and two sealing devices 106 and 107 are provided on the surface 104a. Sealing device 106, 1
07 is a sliding sleeve 1 fitted in the end shaft 102.
08 is in sliding contact with the outer peripheral surface.

[0005] An annular end member 109 is mounted on the end shaft 102 side of the roller 105 of the mounting housing 104, and a sealing device 110 is provided on the facing surface 109 a of the end member 109. Part 102
The sliding sleeve 111 is in sliding contact with the outer peripheral surface of the sliding sleeve 111 fitted into the sliding sleeve 111.

Thus, the sealing devices 106, 107, 1
10 prevents foreign substances such as dust from entering the bearing 103 and protects the bearing 103.

As a specific application example of the roller guide 100, for example, as shown in FIG. 4, a large number of roller guides 100 are arranged and arranged on both sides of a conveying path of a long casting 202 which is cast from a mold 201 of a continuous casting machine 200. , Long castings 202
Some functions as a means for changing the direction and conveying means.

In such an application, the roller guide 100
A large load is applied, and the rotation accuracy of the roller guide 100 (it is desirable that the occurrence of eccentricity and backlash is small).
This may affect the dimensional accuracy (thickness, flatness, etc.) of the long casting 202 by the roller guide 1.
Therefore, high-precision rotation by the bearing 103 provided for the motor 00 is required.

In order to protect the bearing 103, sealing devices 106, 107, 110 and the like are provided.

FIGS. 5 (a) and 5 (b) are cross-sectional views of the conventional sealing devices 120 and 121, which are mainstream. The main lips 120a and 121a and the dust lips 120b, 121b and 121c are made of rubber-like elastic material. It is a general oil seal type equipped with.

However, when used in the continuous casting machine 200, further improvement in heat resistance and abrasion resistance is required, and in the case of a lip made of a rubber-like elastic material (particularly, a dust lip which comes into direct contact with dust). In some cases, it is difficult to satisfy the requirements, and in recent years, a combination type sealing device 130 as shown in FIG. 6A has been adopted as a specification capable of improving durability (heat resistance and abrasion resistance). I have.

The sealing device 130 includes a resin ring 131 (for example, PTFE or the like) that comes into contact with a sliding surface, and a biasing ring 132 made of a rubber-like elastic body that abuts on the outer peripheral side of the resin ring 131 to apply a tightening force. It is composed of two members.

[0013]

However, when used in the above-mentioned continuous casting machine 200 or the like, since it is used in an environment where there is a lot of dust such as metal powder, a large amount of dust penetrates. When dust 150 enters between the sealing device 130 and the holding groove 140 of the housing holding the sealing device 130 as shown in FIG.
Between the sliding surface (the surface of the shaft 133) and the urging ring 13
Gaps G101, G1 between the resin ring 131 and the resin ring 131
02 and the like, dust 150 intrudes into contact gaps G101 and G101.
Wear occurs at the interface 102.

If the interface is worn as described above, there is a concern that the sealing performance and the durability of the sealing device 130 may be reduced.

SUMMARY OF THE INVENTION 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 the invasion of foreign substances such as dust in a combination-type sealing device and maintain the sealing performance. An object of the present invention is to provide a sealing device capable of improving durability.

[0016]

In order to achieve the above object, according to the present invention, an annular gap formed by two opposing surfaces is fitted into an annular groove formed on one of the surfaces, and the other is inserted into an annular groove formed on the other surface. A seal member having a sliding surface that abuts the surface,
In a sealing device including an urging member that abuts against the sealing member and urges the other surface, the sealing device includes, at an axial end portion, an lip portion that abuts on the other surface. Features.

According to this, in addition to the heat resistance and abrasion resistance obtained by the combination-type sealing device, the scraper effect of the lip portion prevents dust and sealing fluid from entering the sliding surface of the sealing member, thereby improving durability. It is possible to improve the performance.

The sealing member may include a lip portion having a tapered portion abutting on a sidewall portion of the annular groove to be fitted, and a tapered portion of the lip portion and an end opposite to the tapered portion. It is also preferable to provide a squeeze allowance to be brought into contact with the rim.

The opening of the annular groove is closed by the interference between the tapered portion of the lip portion of the seal member and the end opposite to the tapered portion to the side wall surface of the annular groove, and dust into the annular groove is reduced. And the intrusion of a sealed fluid or the like is suppressed.

The tapered portion provided on the lip generates an urging force for pressing the lip against the other surface by contacting the side wall surface of the annular groove.

The seal member has a lip portion having a lip tip located substantially on the same surface as the sliding surface with the other surface, and a small radial cross section between the lip portion and the sliding surface. It is also preferable to provide a constricted portion.

The constricted portion allows the posture of the lip portion to be easily changed, suppresses the influence of the change in the posture of the lip portion on the sliding surface of the seal member, and lowers the sealing function on the sliding surface. Nothing.

It is also preferable that the urging member has at least two annular projections that are axially separated and abut against a peripheral wall surface of the annular groove facing the groove bottom.

With this arrangement, regarding the biasing member, the surface pressure distribution shape of the peripheral wall surface facing the groove bottom of the annular groove forms two peaks spaced apart in the axial direction, and a plurality of pressure members having increased surface pressures are formed. Step sealing is performed, and the sealing performance is improved.

With respect to the sealing member, the reduction in the urging force applied to both ends in the axial direction is compensated for, and the sealing performance is improved by making the distribution of the surface pressure on the other sliding surface more uniform.

It is also preferable that the urging member is a rubber-like elastic body and the sealing member is made of a resin material.

[0027]

(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 has a rectangular cross-sectional annular groove 2b provided in the shaft hole 2a. It is embedded in.

FIG. 2 is a view showing a state in which a resin ring 5 as a sealing member and a biasing ring 6 made of a rubber-like elastic body as a biasing member are removed from the annular groove 2b and are not assembled to the annular groove 2b. .

The sealing device 1 according to this embodiment is used as a device for suppressing intrusion of foreign matter such as dust into a bearing portion of a roller guide used in a continuous casting machine as shown in FIG. 4, for example. Figure 1 below
The configuration of the sealing device 1 will be described with reference to FIG.

The resin ring 5 is made of a PTFE material, and has a sliding surface 5a whose inner peripheral side is in contact with the outer peripheral surface 3a of the shaft 3,
The outer peripheral side is a pressure receiving surface 5b that receives the urging force of the urging ring 6. Then, the outer peripheral surface 3a is brought into contact with the outer peripheral surface 3a at the axial end of the atmosphere side A (the side where a bearing (not shown) is housed is the bearing side B)) into which dust or the like intrudes, and the sealing property (in this embodiment) In this case, a lip portion 5c that mainly exerts a dust scraper function) is integrally provided.

The lip portion 5c has two lip surfaces 5e and 5f which spread at an acute angle from each other toward the bearing side B from a lip tip portion 5d which contacts the outer peripheral surface 3a.
It has. The lip surface 5e on the outer peripheral surface side is a tapered portion inclined in a tapered shape.

The sliding surface 5a and the lip 5c of the resin ring 5
Between them, an arc-shaped constricted portion 5g is formed, and the constricted portion 5g is reduced in cross section. The end 5h on the side of the sliding surface 5a is orthogonal to the axial direction.

As shown in FIG. 1, the axial length of the resin ring 5 is such that the end 5h is in contact with the side wall surface of the annular groove 2b on the bearing side B, and the lip tip 5d is on the atmosphere side A.
Projecting from the side wall surface of the annular groove 2b, and the lip surface 5e.
Abuts on the corner 2c of the side wall surface of the annular groove 2b, and the lip 5
The length is provided with a squeeze allowance for urging c to be depressed.

The urging ring 6 is provided on the pressure receiving surface 5 of the resin ring 5.
The b side is a flat inner peripheral surface 6a, and the outer peripheral surface contacting the groove bottom 2b1 of the annular groove 2b is provided with two annular convex portions 6b and 6c separated in the axial direction, and has a substantially concave cross-sectional shape. .

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 energizing ring 6
Urges the resin ring 5 so that the resin ring 5
The sliding surface 5a of the shaft 3 is in sliding contact with the outer peripheral surface 3a of the shaft 3, and the heat resistance and the wear resistance can be improved as compared with those having a sliding surface (seal lip) made of rubber-like elastic material. It is possible.

Further, due to the scraper effect of the lip portion 5c, the sliding surface 5a of the resin ring 5 for dust, sealing fluid, etc.
It is possible to suppress intrusion into the vehicle and improve durability.

Due to the interference in the axial length of the resin ring 5, the lip surface 5e and the end 5
h comes into contact with the side wall surface of the annular groove 2b, the opening of the annular groove 2b is closed, and the intrusion of dust, sealing fluid and the like into the inside of the annular groove 2b is suppressed.

The tapered lip surface 5e provided on the lip portion 5c generates an urging force for pressing the lip portion 5c against the outer peripheral surface 3a of the shaft 3 by coming into contact with the side wall surface portion of the annular groove 2b. The part 5d is given a tension.

The constricted portion 5g of the resin ring 5 allows the posture of the lip 5c to be easily changed, and the change in the posture of the lip 5c affects the sliding surface 5a of the resin ring 5 (ie, the shaft). The sliding surface 5a, which should be linear in the direction, has an arc shape, or the sliding surface 5a floats on the atmosphere side A, for example, and the sealing function of the sliding surface 5a is not reduced.

The urging ring 6 applies a tightening force to the resin ring 5, but is provided with two annular convex portions 6b and 6c on the peripheral wall surface facing the groove bottom 2b1 of the annular groove 2b. The surface pressure distribution shape of the wall surface is formed so as to form two peaks separated from each other in the axial direction, and a plurality of stages of sealing with increased surface pressure are performed, thereby improving the sealing performance.

The resin ring 5 of the two annular projections 6b, 6c
As for the action, the reduction in the urging force applied to both ends in the axial direction of the resin ring 5 is compensated for, and the surface pressure distribution shape of the sliding surface 5a on the outer peripheral surface 3a of the shaft 3 is made more uniform, thereby improving the sealing performance.

(Embodiment 2) Next, referring to FIG.
A more specific configuration of the material and dimensions of the sealing device 1 described in the first embodiment will be described.

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, graphite (trade name of aromatic polyester), and the like can be used.

R (radius) of the constricted portion 5g of the resin ring 5
The dimension D1 is not more than の of the thickness D2 of the resin ring 5 in consideration of the bending rigidity of the lip 5c.

By setting the angle D3 to 45 degrees or less and the angle D4 to 10 to 15 degrees, stable surface pressure can be concentrated on the lip tip 5d without reducing the rigidity of the lip 5c. Becomes

As the material of the urging 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.

[0049]

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, dust is generated by the scraper effect of the lip portion. It is possible to suppress the intrusion of the sealing member such as the sealing fluid or the like into the sliding surface, thereby maintaining the sealing performance and improving the durability.

The opening of the annular groove is closed by the interference between the tapered portion of the lip portion of the seal member and the end opposite to the tapered portion to the side wall surface of the annular groove, and dust entering the inside of the annular groove is blocked. And the intrusion of a sealed fluid or the like is suppressed.

The tapered portion provided on the lip portion generates an urging force for pressing the lip portion against the other surface by contacting the side wall surface portion of the annular groove.

The constricted portion makes it possible to easily change the position of the lip portion, suppress the influence of the change in the position of the lip portion on the sliding surface of the seal member, and reduce the sealing function on the sliding surface. Nothing.

When the urging member has at least two annular protrusions, the urging member can reduce the surface pressure distribution shape of the peripheral wall surface facing the groove bottom of the annular groove by two peaks apart in the axial direction. The sealing is performed in a plurality of stages with increased surface pressure, and the sealing performance is improved. With respect to the seal member, a reduction in the urging force applied to both ends in the axial direction is compensated for, and the sealing performance is improved by making the surface pressure distribution shape with respect to the other of the sliding surfaces more uniform.

[Brief description of the drawings]

FIG. 1 is a sectional configuration explanatory view of a sealing device according to a first embodiment.

FIG. 2 is a sectional configuration explanatory view of a sealing device according to first and second embodiments.

FIG. 3 is a view for explaining a usage form of a conventional sealing device.

FIG. 4 is a perspective view of a continuous casting machine in which a sealing device is used.

FIG. 5 is an explanatory view of a cross-sectional configuration of a conventional sealing device.

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

[Explanation of symbols]

 Reference Signs List 1 sealing device 2 housing 2a shaft hole 2b annular groove 2b1 groove bottom 2c corner 3 shaft 3a outer peripheral surface 4 annular gap 5 resin ring (seal member) 5a sliding surface 5b pressure receiving surface 5c lip portion 5d lip tip portion 5e, 5f lip Surface 5g Constriction 5h End 6 Biasing ring (biasing member) 6a Inner peripheral surface 6b, 6c Annular protrusion A Atmosphere side B Bearing side

Claims (5)

[Claims] 1. A seal member having a sliding surface fitted into an annular groove formed on one surface of an annular gap formed by two opposing surfaces and abutting on the other surface; A sealing device comprising: a biasing member that abuts against the other surface to urge the other surface, wherein a sealing portion is provided at an axial end of the sealing member with a lip portion that abuts the other surface. apparatus. 2. The sealing member has a lip portion having a tapered portion abutting on a side wall surface portion of an annular groove to be fitted, and a tapered portion of the lip portion and an end opposite to the tapered portion. The sealing device according to claim 1, further comprising a squeezing allowance that abuts on the sealing member. 3. The lip portion having a lip tip located substantially on the same surface as the sliding surface with the other surface, and a small radial cross section between the lip portion and the sliding surface. The sealing device according to claim 1, further comprising a constricted portion. 4. The device according to claim 1, wherein the urging member includes at least two annular protrusions that are axially separated and abut on a peripheral wall surface of the annular groove facing the groove bottom. The sealing device according to claim 1. 5. 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.