JP2003035369A - Sealing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high performance sealing device which can excellently prevent a noise generating phenomenon caused by the stick-slip and can avoid pressure accumulation. SOLUTION: The sealing device consists of a seal member 2 which is slidably and sealingly brought into contact with a surface of a shaft 50, and a cushioning material 3 attached to a housing 51 so as to be located between the seal member 2 and the housing 51. A groove 33 for making the sealing object side O of the sealing device communicate with the opposite side A is provided on that surface of a rubber-like elastic body 32 of the cushioning material 3 which faces the seal member 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing device used as a dust seal for reciprocating motion of, for example, a hydraulic cylinder.

[0002]

2. Description of the Related Art Conventionally, as a sealing device which functions as a dust seal for reciprocating movement, one having a structure as shown in FIG. 4 is known. That is, the sealing device 101
As shown in FIG. 4, between the shaft 150, which is the two members forming the gap, and the housing 151, is arranged in the mounting groove 152 at the end portion A of the housing 151 opposite to the sealing target side, and is fitted into the housing 151. A metal ring 102 is baked on the fitting portion, and has two seal lip portions 103 and 104 extending to the sealing target side O and the non-sealing target side A, respectively, and slidably sealingly contacting the surface of the shaft 150.

Here, FIG. 4 (a) shows an example in which the sealing device 101 constitutes a sealing system in which a buffer ring 110 and a rod seal 111 are arranged on the side opposite to the sealing target, and FIG. 4 (b). Shows an example in which the sealing device 101 is arranged on the non-sealing target side A of the rod seal 112 and constitutes a sealing system in which grease G is supplied between the sealing device 101 and the rod seal 112.

[0004]

The sealing device 1 functioning as a dust seal used in FIG. 4 of the above-mentioned prior art.
No. 01 was provided in the shape described above as a countermeasure for stick-slip, but in this case as well, stick-slip may occur and a sounding phenomenon occurred. This pronunciation phenomenon makes the user uncomfortable and makes the user anxious about whether the device is out of order, and thus it has been desired to be prevented as much as possible.

When the sealing device 101 is used in the sealing system shown in FIG. 4A, the sealing device 101
Oil may be accumulated between the rod seal 111 and the rod seal 111 to cause pressure accumulation. If such accumulated pressure is left as it is, back pressure damage will be caused.

The present invention solves the above-mentioned problems of the prior art, and an object of the present invention is to provide a high-performance sealing device which satisfactorily prevents a sounding phenomenon due to stick-slip and avoids pressure accumulation. Especially.

[0007]

In order to achieve the above object, the present invention provides a sealing device for sealing a gap formed between two members that reciprocate relative to each other. A seal member slidably and slidably contacting one of the surfaces of the members, and a cushioning member interposed between the seal member and the other of the two members and attached to the other of the two members. It is characterized by

Therefore, even if stick-slip occurs in the seal member, the vibration is absorbed by the cushioning means, so that the sound generation phenomenon is reduced by absorbing the vibration. Therefore, the pronunciation phenomenon does not make the user uncomfortable or make the user uneasy about whether or not the device is out of order.

It is preferable that the buffer means comprises a metal ring on the other side of the two members and a rubber-like elastic body on the side of the sealing member.

Accordingly, the buffer means is fixed to the other of the two members by the metal ring, and the rubber-like elastic body can absorb the vibration due to the stick slip of the seal member.

It is preferable that the rubber-like elastic body forming the buffer means is made of a material having a hardness lower than that of the seal member.

As a result, the rubber-like elastic body of the cushioning means and the sealing member have different damping factors and elastic moduli, and the vibration due to stick slip of the sealing member can be absorbed by the rubber-like elastic body of the cushioning means.

It is preferable that the buffer means is provided with a groove for communicating between the side to be sealed and the side not to be sealed.

As a result, the high-pressure oil on the sealing target side is discharged to the anti-sealing target side through the groove, so that the oil is prevented from accumulating between the seal on the sealing target side and the accumulated pressure. it can. Therefore, it is possible to prevent back pressure damage when the accumulated pressure is left.

It is preferable that the groove of the buffer means is formed on a surface of the rubber-like elastic body constituting the buffer means facing the seal member.

Thus, the groove can be easily formed.

It is preferable that the seal member has a sub-lip portion that closes the groove of the buffer means from the side opposite to the hermetically sealed side.

As a result, normally, it is possible to prevent dust and the like from entering the groove from the side to be sealed, and when the oil on the side to be sealed has a high pressure, the sub-lip portion opens the groove accordingly and the target to be sealed is not sealed. Oil can be discharged to the side.

It is preferable that the sealing member has two seal lips that slidably sealingly contact one surface of the two members and extend to the sealing target side and the non-sealing target side, respectively.

With this, it is possible to function as a dust seal against stick-slip.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be illustratively described in detail below with reference to the drawings. However, the dimensions of the components described in this embodiment,
Unless otherwise specified, the material, the shape, the relative arrangement, and the like are not intended to limit the scope of the present invention thereto.

An embodiment will be described with reference to FIGS. FIG. 1 is a half sectional view showing a sealing device according to an embodiment. FIG. 2 is a half sectional view showing a seal member of the sealing device according to the embodiment. FIG. 3 is a perspective view showing a part of the cushioning material of the sealing device according to the embodiment.

The sealing device 1 of FIG. 1 is used as a reciprocating seal in a hydraulic cylinder or the like, and is used in various sealing systems as shown in FIG. It functions as a dust seal for reciprocating movement that prevents dust and the like from entering the interior.

As shown in FIG.
Anti-sealing of the housing 51 formed in the housing 51 in order to seal the annular gap between the surface of the shaft 50 that relatively reciprocates as a member and the surface of the housing 51 that concentrically surrounds the shaft 50. Mounting groove 52 on the target side A end
And is slidably abutted on the surface of the shaft 50.

The structure of the sealing device 1 is such that the sealing member 2 slidably sealingly contacts the surface of the shaft 50, and the sealing member 2
And a cushioning member 3 as a cushioning means which is interposed between the housing 51 and the housing 51 and is attached to the housing 51.

The seal member 2 has the shape shown in FIG.
Sealing side O that makes slidable sealing contact with the surface of the shaft 50
And the oil lips 2 that extend to the side A that is not sealed.
1 and the dust lip portion 22. By having the two lip portions 21 and 22 in this way, it is possible to function as a dust seal against stick-slip.

The dust lip portion 22 is provided with a sub-lip portion 23 which is in contact with the cushioning material 3 and closes the groove 33 of the cushioning material 3 from the side A opposite to the sealing target side.

The fitting portion 24 for holding these two oil lip portions 21 and the dust lip portion 22 of the seal member 2 supports the roots of both lip portions 21 and 22 at the end portion A on the side opposite to the sealed side, A cylindrical portion 24a is formed by expanding the sealing target side O in the outer diameter direction. The cylindrical portion 24a is shown in FIG.
As shown in FIG. 3, when the cushioning material 3 is held, it is compressed toward the inner diameter side and a pressing force for pressing both lip portions 21 and 22 against the surface of the shaft 50 can be exerted.

A material having a relatively high hardness such as polyurethane rubber is used for the seal member 2.

On the other hand, as shown in FIG. 3, the cushioning material 3 has a tubular portion 3a extending in the axial direction and an inward flange portion 3b at the end portion A of the tubular portion 3a on the non-sealing target side. The cushioning material 3 is formed by baking and integrating a metal ring 31 made of SPCC or the like on the housing 51 side and a rubber-like elastic body portion 32 made of nitrile rubber or the like on the seal member 2 side on the inner diameter side.

As shown in FIG. 1, the metal ring 31 of the cushioning material 3 is mounted in the mounting groove 52 of the housing 51 and pressed by the plate 53 from the side A opposite to the sealing target, so that the cushioning material 3 is fixed. To do. Reference numeral 54 is a bolt for fixing the plate 53 to the housing 51.

The rubber-like elastic portion 32 of the cushioning material 3 is made of a material having a hardness lower than that of the seal member 2 such as nitrile rubber. For this reason, the rubber-like elastic body portion 32 of the cushioning material 3 and the sealing member 2 have different damping rates and elastic moduli, and vibration due to stick-slip of the sealing member 2 is damped.
Can be absorbed by the rubber-like elastic body portion 32.

A groove 33 is provided on the surface of the cushioning member 3 facing the seal member 2 of the rubber-like elastic member 32 so as to communicate between the sealing target side O and the non-sealing target side A of the apparatus. Groove 33
Is formed on the surface of the rubber-like elastic body portion 32, as shown in FIG. 3, so that it can be easily formed. It should be noted that modifications such as providing the groove 33 as a hole penetrating the inside of the rubber-like elastic body portion 32 are possible.

The groove 33 is, as shown in FIG.
Even when attached, the seal member 2 does not crush it and communicates,
At the time of mounting, the non-sealing target side A of the groove 33 is closed by the sub-lip portion 23 of the seal member 2. Specifically, the seal member 2
The sub-lip portion 23 is the inward flange portion 3b of the cushioning material 3.
By abutting on the inner diameter end surface of, the passage through the groove 33 is prevented from communicating from the sealing target side O to the non-sealing target side A. Therefore, it is usually possible to prevent dust and the like from entering the groove 33 from the side A not to be sealed.

In the sealing device 1 having the above-mentioned structure, when stick-slip occurs, the vibration is absorbed by the cushioning material 3, so that the sound generation phenomenon is reduced by absorbing the vibration. Therefore, the pronunciation phenomenon makes the user uncomfortable,
The user will not be worried about a device failure.

Further, when the oil on the sealing target side O has a high pressure before pressure is accumulated between the oil on the sealing target side O and the seal, the sub-lip portion 23 opens the passage from the groove 33 in response to the high pressure and the high pressure is generated. Since the oil on the sealed target side O is discharged to the anti-sealed target side A through the groove 33, it is possible to prevent accumulation of oil between the seal on the sealed target side O and accumulation of pressure. Therefore, it is possible to prevent back pressure damage when the accumulated pressure is left.

[0037]

As described above, according to the present invention, between the seal member slidably sealingly contacting the surface of either one of the two members forming the gap, and the seal member and the other of the two members. By providing the cushioning means attached to the other of the two members via the interposition, even if a stick-slip occurs in the seal member, the vibration is absorbed by the cushioning means. Is reduced. Therefore, the pronunciation phenomenon does not make the user uncomfortable or make the user uneasy about whether or not the device is out of order.

The buffer means includes a metal ring on the other side of the two members,
The cushioning means is fixed to the other of the two members with the metal ring, and the rubber-like elastic body on the seal member side can absorb the vibration due to the stick-slip of the seal member. .

Since the rubber-like elastic body constituting the buffer means is a material having a hardness lower than that of the seal member, the rubber-like elastic body of the buffer means and the seal member have different damping factors and elastic moduli, and the seal member Vibration due to stick-slip can be absorbed by the rubber-like elastic body of the cushioning means.

Since the buffer means is provided with the groove for communicating between the sealing target side and the anti-sealing target side, the high pressure oil on the sealing target side is discharged to the anti-sealing target side through the groove. It is possible to prevent the accumulation of oil due to the accumulation of oil between the seal and the seal on the side to be sealed. Therefore, it is possible to prevent back pressure damage when the accumulated pressure is left.

Since the groove of the buffer means is formed on the surface of the rubber-like elastic body that constitutes the buffer means facing the seal member,
The groove can be easily formed.

Since the seal member has the sub-lip portion that closes the groove of the cushioning means from the side of the non-sealing target, it is usually possible to prevent dust and the like from entering the groove from the side of the non-sealing target and to seal the groove of the sealing target side. When the pressure of the oil becomes high, the sub-lip portion opens the groove accordingly and the oil can be discharged to the non-sealing target side.

The seal member has two seal lips that slidably sealingly contact one surface of the two members and extend to the sealed target side and the non-sealed target side, respectively, to prevent stick-slip. It can function as a dust seal.

[Brief description of drawings]

FIG. 1 is a half sectional view showing a sealing device according to an embodiment.

FIG. 2 is a half cross-sectional view showing a seal member of the sealing device according to the exemplary embodiment.

FIG. 3 is a perspective view showing a part of the cushioning material of the sealing device according to the embodiment.

FIG. 4 is a half cross-sectional view showing a usage example using a conventional sealing device.

[Explanation of symbols]

1 Sealing device 2 Seal member 3 cushioning material 3a tube 3b Inward flange 21 Oil lip 22 Dustrip 23 Sub lip part 24 Fitting part 24a cylindrical part 31 metal ring 32 Rubber-like elastic body 33 groove

Claims (7)

[Claims] 1. A sealing device for sealing a gap formed between two members that reciprocate relative to each other, the seal member slidably sealingly contacting either surface of the two members forming the gap. And a cushioning means which is interposed between the seal member and the other of the two members and is attached to the other of the two members. 2. The sealing device according to claim 1, wherein the cushioning means includes a metal ring on the other side of the two members and a rubber-like elastic body on the seal member side. 3. The sealing device according to claim 2, wherein the rubber-like elastic body forming the cushioning means is made of a material having a hardness lower than that of the sealing member. 4. The sealing device according to claim 2, wherein the cushioning means is provided with a groove for communicating between the sealed side and the non-sealed side. 5. The sealing device according to claim 4, wherein the groove of the cushioning means is formed on a surface of the rubber-like elastic body forming the cushioning means facing the sealing member. 6. The sealing device according to claim 4, wherein the sealing member has a sub-lip portion that closes the groove of the cushioning means from the side opposite to the sealing target side. 7. The seal member has two seal lips that slidably sealingly contact one surface of the two members and extend to the sealed target side and the non-sealed target side, respectively. The sealing device according to any one of 1 to 6.