JP3785809B2 - Sealing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sealing device used for a rotary shaft sealing portion of various devices, and particularly to a device provided with a resin seal lip.
[0002]
[Prior art]
Conventionally, as this type of sealing device, for example, there is a device as shown in FIG. That is, the sealing device 100 is mounted between a housing 101 and a rotating shaft 102 which are assembled concentrically and relatively rotatably.
[0003]
The sealing device 100 includes a seal member 104 that is fitted and fixed in the shaft hole 103 of the housing 101 and holds the seal lip 105, and a seal lip 105 that is integrally assembled to the seal member 104.
[0004]
The seal member 104 includes a metal outer ring 106 and an inner ring 107, and a rubber-like elastic body 108 baked integrally with the outer ring 106.
[0005]
The outer ring 106 and the inner ring 107 are annular members having an L-shaped cross-section in which the end on the atmosphere side A is bent inward, and the inner ring 107 is fitted to the inner periphery of the outer ring 106, The outer end portion of the seal lip 105 is sandwiched between the flange portions, and the sealing fluid side O end edge of the outer ring 106 is caulked to the inner ring 107 so as to be integrally provided.
[0006]
The gap between the outer end of the seal lip 105 and the outer ring 106 is sealed by a rubber-like elastic body 108 baked on the outer ring 106.
[0007]
The seal lip 105 is inclined so as to gradually become a small diameter toward the axially sealed fluid side O and extends in a cylindrical shape, and the inner peripheral surface of the tip thereof is slidably sealingly contacted with the rotary shaft 102. .
[0008]
Further, a thread groove 109 is formed on the inner peripheral surface of the seal lip 105 so as to push back the sealing fluid that gets wet on the sliding surface by a pump action by relative rotation with the rotating shaft 102.
[0009]
As shown in FIG. 5B, the screw groove 109 is a substantially trapezoidal groove, and a plurality of screw grooves 109 are partially provided in the circumferential direction of the seal lip 105.
[0010]
In such a sealing device 100, since the thread groove 109 is inclined so as to be narrowed from the tip of the seal lip 105 toward the atmosphere side A, the pumping action is exerted in either the left or right rotation direction with either the right or left inclination. And push back the sealing fluid.
[0011]
[Problems to be solved by the invention]
However, in the case of the prior art described above, the seal lip 105 is generally formed of a tetrafluoroethylene resin (hereinafter referred to as PTFE) as a material having excellent oil resistance. When it is large or has a fine scratch, a minute gap is generated between the seal lip 105 and the rotating shaft 102, and a small amount of air leakage may occur in the airtight test.
[0012]
Sealing fluid is viscous and rarely leaks, but it is necessary to prevent the leakage of air such as air and gas. To prevent this, a coating process such as wax may be added to the PTFE surface. Although it was possible, there was a possibility that the dispersion of the performance might be caused by the quality of the coating.
[0013]
Further, when the PTFE surface is scratched as described above, it may cause a fatal defect, and the seal lip 105 is required to be handled carefully.
[0014]
The present invention has been made in order to solve the above-described problems of the prior art, and an object of the present invention is to provide a highly reliable sealing device that improves sealing performance and facilitates handling. It is in.
[0015]
[Means for Solving the Problems]
In order to achieve the above object, in the present invention, there is provided a sealing device that seals between two members that are assembled concentrically and relatively rotatably, and includes a resin seal lip extending toward the sealing fluid side. ,
Is disposed on the atmosphere side end portion of the sliding surface of the resin seal lip, the protrusion of the resin seal lip of the second member protrudes a member side sealing contact freely the member and the sliding of sliding Provided with a sealing means made of a rubber-like elastic body.
[0016]
Therefore, it is possible to seal with the sealing means made of rubber-like elastic material regardless of the surface roughness and fine scratches of the resin seal lip. Occurrence is eliminated, the sealing performance can be improved, and the resin seal lip may be slightly scratched, so that it is easy to handle.
[0017]
The sealing means is preferably a ring supported by a support portion extending from a rubber-like elastic body baked on a metal ring assembled with the resin seal lip.
[0018]
Thereby, the ring made of a rubber-like elastic body is disposed at the atmosphere side end portion of the sliding surface of the resin seal lip, and can have a continuous contact surface slidably and in sealing contact with the other member.
[0019]
The sealing means is preferably formed integrally with a rubber-like elastic body baked on a metal ring having the resin sealing lip assembled thereto.
[0020]
Thereby, a sealing means can be provided, without requiring other components. Further, if the sealing means is a ring, the support portion can be formed integrally.
[0021]
It is preferable that a screw groove is provided on the sliding surface of the resin seal lip.
[0022]
As a result, the sealing fluid can be pushed back by the pumping action of the thread groove, and the sealing means made of rubber-like elastic body is unlikely to be hardened or corroded by the sealing fluid.
[0023]
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.
[0024]
FIG. 1 shows a configuration of a sealing device according to an embodiment of the present invention, and FIG. 2 shows an operating state of the sealing device.
[0025]
Reference numeral 1 denotes a sealing device, which seals between the rotating shaft 2 and the housing 3 as two members that are assembled concentrically and relatively rotatably. The sealing device 1 includes a substantially annular sealing member 4 and It is comprised from the resin-made seal lips 5 integrally provided in the seal member 4. As shown in FIG.
[0026]
As shown in FIG. 1, the seal lip 5 is formed into a plate shape with a tetrafluoroethylene resin (hereinafter referred to as PTFE), which is a resin excellent in oil resistance, and is integrally assembled with the seal member 4. The seal lip 5 is bent between the sealing fluid side O and mounted between the rotary shaft 2 and the housing 3 as shown in FIG.
[0027]
The seal member 4 includes an inner ring 6 as a metal ring and a rubber-like elastic body 7 that is baked integrally with the inner ring 6 and covers the inner ring 6. The inner ring 6 is an annular member provided with an inward flange portion having an L-shaped cross section in which the atmosphere side A edge is bent inward.
[0028]
A support portion 8 extending a rubber-like elastic body 7 baked on the inner end of the inward flange portion extends along the atmosphere side A surface of the seal lip 5, and a seal made of a rubber-like elastic body is attached to the tip of the support portion 8. A ring 9 is provided as a means.
[0029]
As shown in FIG. 2, this rubber-like elastic ring 9 is arranged at the end A on the atmosphere side of the sliding surface of the seal lip 5, has a continuous contact surface with respect to the rotating shaft 2, and slides Freely sealed contact.
[0030]
In the present embodiment, the ring 9 is formed integrally with the rubber-like elastic body 7 together with the support portion 8.
[0031]
A rubber-like elastic body 7 is interposed between the outer periphery of the cylindrical portion of the inner ring 6 and the inner periphery of the housing 3 to seal the outer periphery fitting portion.
[0032]
The seal lip 5 is inclined so as to gradually become a small diameter toward the axial sealing fluid side O and extends in a cylindrical shape, and the inner peripheral surface of the tip presses the ring 9 against the rotary shaft 2.
[0033]
A thread groove 10 is formed on the inner peripheral surface of the seal lip 5, and a pumping action is performed at an inclined portion of each thread groove 10 according to each rotation direction by relative rotation with the rotation shaft 2. The sealing fluid leaking between the sliding surfaces is pushed back. The screw groove 10 is a substantially trapezoidal groove, and a plurality of screw grooves 10 are partially provided in the circumferential direction of the seal lip 5.
[0034]
In the present embodiment, the shape of the thread groove 10 is substantially trapezoidal, but is not limited to this, and may be a screw shape that generates an action of pushing the sealing fluid back to the sealing fluid side O by relative rotation with the rotating shaft 2. That's fine.
[0035]
In the sealing device 1 configured as described above, a ring 9 made of a rubber-like elastic body provided via a support portion 8 extending a rubber-like elastic body 7 baked on the inner end of an inward flange portion has a seal lip. 5 is sealed to the rotary shaft 2 on the atmosphere side A, and the seal lip 5 made of PTFE is sealed with the rotary shaft 2 by the ring 9 regardless of the surface roughness of the seal lip 5 and the fine scratches. Therefore, there is no air leakage in the airtight test. Further, it is not necessary to perform coating processing on the surface of the seal lip 5 as in the prior art.
[0036]
Further, as described above, since the rotating shaft 2 and the rubber-like elastic ring 9 are in sealing contact to obtain a sealing property, even if the seal lip 5 formed of PTFE is damaged during handling, the seal A stable sealing performance can be obtained regardless of the damage of the lip 5, and the handling of the sealing lip 5 is facilitated.
[0037]
Further, the sealing fluid is sealed by the sliding surface of the seal lip 5 while being pushed back by the pumping action of the thread groove 10, so that the ring 9 made of rubber-like elastic material is deteriorated by hardening or corrosion due to the sealing fluid. Hateful.
[0038]
Not only the sealing device of the present embodiment but also a sealing device having a configuration in which the ring 9 is in sealing contact with the rotary shaft 2, for example, a seal between the inner ring 6 and the outer ring 11 as shown in FIG. A lip 5 and a rubber-like elastic body 7 provided with a ring 9 on the inner diameter side are sandwiched, and a sealing fluid side O edge of the inner ring 6 is caulked integrally, as shown in FIG. Even if the dust lip 12 is provided, the effect of the present embodiment can be obtained similarly.
[0039]
In addition, the present invention can be applied to a case where a seal lip is provided on the outer peripheral side, and the side opposite to the seal target side is the atmosphere side. However, the present invention is not limited to this, and the material used is PTFE. It is not limited.
[0040]
【The invention's effect】
The present invention is provided with a sealing means made of a rubber-like elastic body that is disposed at the atmospheric end of the sliding surface of the resin seal lip and that is slidably sealed and in contact with either one of the two members. Therefore, it is possible to seal with a sealing means made of rubber-like elastic material regardless of the surface roughness and fine scratches of the resin seal lip, so there is no need to coat the seal lip and air leaks in the airtight test Occurrence is eliminated, the sealing property can be improved, and the resin seal lip may be slightly scratched, so that it can be handled easily.
[0041]
The seal means is a ring supported by a support portion extending from a rubber-like elastic body baked on a metal ring having a resin-made seal lip assembled thereto, and the rubber-like elastic body ring is formed on the sliding surface of the resin-made seal lip. It arrange | positions at the atmospheric | air-end side edge part, and has a continuous contact surface slidably with the other member, and can carry out sealing contact.
[0042]
The sealing means can be provided with the sealing means without the need for other parts by being integrally formed with the rubber-like elastic body baked on the metal ring to which the resin seal lip is assembled. Further, if the sealing means is a ring, the support portion can be formed integrally.
[0043]
By providing a screw groove on the sliding surface of the resin seal lip, the sealing fluid can be pushed back by the pumping action of the screw groove, and the sealing means made of rubber-like elastic material is not deteriorated by hardening or corrosion due to the sealing fluid. Hard to occur.
[Brief description of the drawings]
FIG. 1A is a cross-sectional view showing a sealing device according to an embodiment, and FIG. 1B is a plan view showing a seal lip from the atmosphere side.
FIG. 2 is a cross-sectional view showing an operating state of the sealing device.
FIG. 3 is a cross-sectional view showing a sealing device according to an example of the embodiment.
FIG. 4 is a cross-sectional view showing a sealing device according to an example of an embodiment.
FIG. 5 (a) is a cross-sectional view showing an operating state of a conventional sealing device, and FIG. 5 (b) is a plan view showing a seal lip from the atmosphere side.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Sealing device 2 Rotating shaft 3 Housing 4 Seal member 5 Seal lip 6 Inner ring 7 Rubber-like elastic body 8 Support part 9 Ring 10 Screw groove 11 Outer ring 12 Dustrip 100 Sealing device 101 Housing 102 Rotating shaft 103 Shaft hole 104 Seal member 105 Seal lip 106 Outer ring 107 Inner ring 108 Rubber elastic body 109 Thread groove

Claims (4)

In a sealing device that seals between two members that are assembled concentrically with each other so as to be relatively rotatable, and includes a resin seal lip extending toward the sealing fluid side,
Is disposed on the atmosphere side end portion of the sliding surface of the resin seal lip, the protrusion of the resin seal lip of the second member protrudes a member side sealing contact freely the member and the sliding of sliding A sealing device provided with a sealing means made of a rubber-like elastic body.   2. The sealing device according to claim 1, wherein the sealing means is a ring supported by a support portion extending from a rubber-like elastic body baked on a metal ring assembled with the resin seal lip.   3. The sealing device according to claim 1, wherein the sealing means is integrally formed with a rubber-like elastic body baked on a metal ring having the resin seal lip assembled thereto.   4. The sealing device according to claim 1, wherein a thread groove is provided on a sliding surface of the resin seal lip.

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