JP3591221B2 - Sealing device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a sealing device used for a shaft sealing portion of various devices.
[0002]
[Prior art]
Conventionally, as this type of sealing device, for example, there is a sealing device shown in FIG.
[0003]
As shown in the figure, the sealing device 100 seals an annular gap between the shaft 200 and the cylindrical housing 300 so that fluid such as oil on the sealed fluid side O does not leak to the atmosphere side A. It is.
[0004]
The sealing device 100 is generally sandwiched between a metal ring 101, a rubber-like elastic sealing member 102 integrally formed with the metal ring 101, and the metal ring 101 and the rubber-like elastic sealing member 102. And a resin-made sealing member 103.
[0005]
The rubber-like elastic sealing member 102 includes an outer peripheral sealing portion 102 b that hermetically contacts the inner peripheral surface of the housing 300, and a lip 102 a that slides on and seals the shaft 200.
[0006]
The resin-made sealing member 103 supports the root of the lip 102a of the rubber-like elastic sealing member 102 to suppress excessive deformation of the lip 102a, and slides on the shaft 200 to exhibit sealing properties. I have.
[0007]
With such a configuration, an annular gap between the shaft 200 and the cylindrical housing 300 is sealed.
[0008]
[Problems to be solved by the invention]
However, in the case of the prior art as described above, leakage of the sealing fluid cannot be sufficiently prevented due to sliding wear of the lip 102a of the sealing member 102 made of rubber-like elastic material.
[0009]
The fluid leaking from the lip 102a to the atmosphere side A is prevented to some extent by the resin sealing member 103, but the resin sealing member 103 has a function of suppressing deformation of the lip 102a due to the characteristics of the material and the like. Mainly, the sealing property was insufficient.
[0010]
In addition, there is a limit in suppressing the deformation of the lip 102a by the resin sealing member 103, and when the sealing fluid is at a high pressure, the deformation of the lip 102a cannot be sufficiently suppressed.
[0011]
SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the related art, and an object of the present invention is to provide a sealing device having a simple configuration and excellent sealing performance even under high pressure.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, there is provided a metal ring having a cylindrical portion and an inward flange portion bent in an inner diameter direction from one end of the cylindrical portion; A first sealing member made of a rubber-like elastic material integrally formed with the metal ring, having a radial portion provided substantially parallel to the orientation flange portion, and a lip portion connected to the radial portion; An auxiliary metal ring provided between the first seal member and the inward flange portion, the auxiliary metal ring including a support portion for supporting a root of a lip portion provided on the first seal member; A second sealing member made of a resin material having a sandwiched portion sandwiched between the orientation flange portion and the auxiliary metal ring, and a lip portion bent from the sandwiched portion in the axial direction; Fluid to the sliding surface of the lip provided on the sealing member The pump screws provided with, characterized in that a pump screws for sending fluid into the second well sealed side on the sliding surface of the lip provided on the sealing member.
[0013]
Therefore, when the sealing fluid leaks from the lip portion provided on the first seal member to the atmosphere side, the sealing fluid is returned to the sealing side by the pump screw provided on the sliding surface of the lip portion, and further, In the case of leakage from the part to the atmosphere side, it is returned toward the sealing side by a pump screw provided on the sliding surface of the lip provided on the second sealing member, and even if the sealing fluid is high pressure, the first Since the base of the lip provided on the seal member is supported by the auxiliary metal ring, its deformation is suppressed.
[0014]
It is preferable that a plurality of protrusions are provided on the contact surface of the inward flange portion with the second seal member.
[0015]
Therefore, co-rotation of the second seal member with the shaft is prevented.
[0016]
The pump screw provided on the sliding surface of the lip provided in the second seal member has an inclination angle of 35 to 75 degrees with respect to the shaft, and the depth of the screw is greater than 0 and 75% of the thickness of the lip. The following is recommended.
[0017]
The auxiliary metal ring may have a plurality of protrusions that are independent in the circumferential direction.
[0018]
Therefore, the strength of the auxiliary metal ring increases.
[0019]
The auxiliary metal ring may be provided with a communication portion for communicating the first seal member and the second seal member.
[0020]
Therefore, the auxiliary metal ring is bonded by the communicating portion by the first seal member and the second seal member during molding.
[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, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention only to them unless otherwise specified. Absent.
[0022]
1 and 2 show a sealing device according to an embodiment of the present invention. FIG. 1 is a partial cross-sectional view of a schematic configuration of the sealing device, and FIG. 2 is a schematic configuration cross-sectional view showing a state where the sealing device is assembled.
[0023]
As shown in the figure, the sealing device 1 seals an annular gap between the shaft 80 and a housing 90 which is a cylindrical member so that fluid such as oil on the sealed fluid side O does not leak to the atmosphere side A. It is what you are doing.
[0024]
The sealing device 1 generally includes a metal ring 20, a first seal member 30 formed integrally with the metal ring 20, an auxiliary metal ring 40 supporting the first seal member 30, A second seal member 50 sandwiched between the metal rings 40.
[0025]
The metal ring 20 includes a cylindrical portion 21 that is arranged concentrically with the shaft 80 and the housing 90 when assembled, and an inner diameter direction (a direction toward the shaft 80) from one end (the atmospheric side in the assembled state) of the cylindrical portion 21. And an inward flange portion 22 that bends inward.
[0026]
The first seal member 30 is integrally formed so as to cover the outer side and the inner side of the cylindrical portion 21 of the metal ring 20, and is provided substantially parallel to the inward flange portion 22 from the covered portion. It has a radial portion 32 and a lip portion 33 connected to the radial portion 32, and is formed of a rubber-like elastic material.
[0027]
A pump screw 34 is provided on a sliding surface of the lip portion 33 on the shaft 80.
[0028]
When the first seal member 30 is assembled, the outer peripheral portion 31 comes into sealing contact with the inner periphery of the housing 90, and the outer periphery of the lip portion 33 is attached with the spring ring 6 that applies a tightening force in the radial direction. When the tip of the lip portion 33 slides on the outer peripheral surface of the shaft 80, a fluid such as oil on the sealed fluid side O can be sealed.
[0029]
Further, the pump screw 34 has, for example, a C-shape as shown in the figure, so that the fluid flows to the sealed fluid side O even when the sealing device 1 rotates in any direction with respect to the shaft 80. It has a structure that exerts a pump effect.
[0030]
The auxiliary metal ring 40 is disposed along the atmosphere side A of the first seal member 30, and includes a support portion 41 that supports the root of the lip 33 of the first seal member 30.
[0031]
Therefore, even when the sealed fluid side O is under a high pressure, the lip portion 33 can be prevented from being turned up.
[0032]
Note that, by disposing the tip of the support portion 41 so as to protrude toward the shaft 80 from the root of the lip portion 33, the turning-up of the lip portion 33 can be more reliably prevented.
[0033]
Further, since the strength of the auxiliary metal ring 40 itself can be increased by providing a plurality of independent protrusions 42 in the circumferential direction on the auxiliary metal ring 40, the plate thickness of the auxiliary metal ring 40 can be reduced. In addition, the weight can be reduced and the cost can be reduced.
[0034]
The second seal member 50 includes a clamped portion 51 clamped between the inward flange portion 22 of the metal ring 20 and the auxiliary metal ring 40, a lip portion 52 bent from the clamped portion 51 in the axial direction, and And is formed of a resin material (such as PTFE).
[0035]
The second seal member 50 has a washer shape when the shaft 80 is not inserted. The inner edge of the second seal member 50 is bent while being expanded along the outer peripheral surface of the shaft 80 by the insertion of the shaft 80, and the outer peripheral surface of the shaft 80 is bent. Are arranged so as to be slidable.
[0036]
Also, a pump screw 53 is provided on the sliding surface of the lip portion 52 to the shaft 80.
[0037]
The pump screw 53 has a structure that exerts a pump effect such that the fluid flows to the sealed fluid side O by rotating the sealing device 1 with respect to the shaft 80.
[0038]
In addition, the pump screw 53 rotates in one direction when the sealing device 1 is applied to a position where the sealing device 1 normally rotates only in one direction with respect to the shaft 80 and does not rotate much in the other direction. It is preferable to use a helical screw that efficiently exerts a pumping effect on the surface, and when it is applied to a part that rotates in both directions, it exhibits a moderate pumping effect on any rotation. Preferably, there are a number of concentric screws.
[0039]
Further, the depth of the pump screw 53 is preferably set to 75% or less of the plate thickness of the lip portion 52. For example, when the plate thickness of the lip portion 52 is 1.0 (mm), the pump screw 53 has a pitch of 0.3. (Mm), an inclination of 35 to 75 degrees, and a depth of 0.5 mm, it is recognized that an excellent pump effect is exhibited.
[0040]
Further, if a notch (the number is not limited) 43 as a communicating portion is provided at the outer peripheral end of the auxiliary metal ring 40, rubber-like elasticity is formed from the notch 43 during vulcanization molding of the first seal member 30. The material flows into the second seal member 50 side, and the second seal member 50 side and the auxiliary metal ring 40 can be bonded. In this case, a notch may be provided at the end of the outer periphery of the second seal member 50, and a rubber-like elastic material may be poured into this portion to further enhance the adhesiveness.
[0041]
In addition, the co-rotation can be prevented by providing the rotation preventing projection 7 on the contact surface of the inward flange portion 22 of the metal ring 20 with the pinched portion 51 of the second seal member 50.
[0042]
With the sealing device 1 configured as described above, the sealing fluid on the sealing fluid side O is sealed by the outer peripheral portion 31 of the first sealing member 30 on the housing 90 side and the sealing fluid on the shaft 80 side by the first sealing member 30. Sealed by the lip 33.
[0043]
The fluid leaking from the lip 33 is returned to the sealed fluid side O by a pump screw 34 provided on the lip 33.
[0044]
If the pump screw 34 does not return and leaks, it is properly returned to the sealed fluid side O by the pump screw 53 provided on the second seal member 50.
[0045]
As described above, a very excellent sealing performance can be exhibited with a simple configuration.
[0046]
In addition, since the base of the lip portion 33 of the first seal member 30 is supported by the support portion 41 of the auxiliary metal ring 40, the lip portion 33 is prevented from being turned over, and a stable sealing performance even under high pressure. Can be maintained.
[0047]
【The invention's effect】
According to the present invention, the first seal member and the second seal member are provided with a pump screw for feeding a fluid to a sealing side on a sliding surface of a lip provided on the second seal member. When the fluid leaks from the lip provided to the air to the atmosphere, the fluid leaked by the pump screw provided on the sliding surface of the lip is returned to the sealed side, and further leaked from the lip to the atmosphere. In this case, the leaked fluid can be returned toward the sealing side by the pump screw provided on the sliding surface of the lip provided on the second seal member, and the first fluid can be returned even when the sealing fluid is at a high pressure. Since the base of the lip portion provided in the seal member is supported by the auxiliary metal ring, the deformation can be suppressed, so that excellent sealing performance is exhibited even under high pressure with a simple configuration.
[0048]
If a plurality of protrusions are provided on the contact surface of the inward flange portion with the second seal member, co-rotation of the second seal member with the shaft can be prevented.
[0049]
If the pump screw provided on the sliding surface of the lip provided in the second seal member has an inclination angle with respect to the shaft of 35 to 75 degrees and the depth of the screw is an upper limit of 75% with respect to the thickness of the lip, Sealability and eccentricity followability are improved.
[0050]
If a plurality of projections independent in the circumferential direction are provided on the auxiliary metal ring, the strength of the auxiliary metal ring can be increased, so that the thickness of the auxiliary metal ring can be reduced and the weight can be reduced.
[0051]
If the auxiliary metal ring is provided with a communication portion for communicating the first seal member and the second seal member, the auxiliary metal ring is bonded by the communication portion by the first seal member and the second seal member during molding. be able to.
[Brief description of the drawings]
FIG. 1 is a schematic configuration partial cross-sectional view of a sealing device according to an embodiment of the present invention.
FIG. 2 is a schematic configuration sectional view showing a state where a sealing device according to an embodiment of the present invention is assembled.
FIG. 3 is a schematic sectional view showing a state where a sealing device according to a conventional technique is assembled.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Sealing device 20 Metal ring 21 Cylindrical part 22 Inward flange part 30 First seal member 32 Radial part 33 Lip part 34 Pump screw 40 Auxiliary metal ring 41 Support part 42 Projection 43 Notch 50 Second seal member 51 Nipping part 52 Lip part 53 Pump screw 7 Protrusion for preventing rotation 80 Shaft 90 Housing O Sealed fluid side A Atmosphere side

Claims (4)

A metal ring having a cylindrical portion and an inward flange portion bent in an inner diameter direction from one end of the cylindrical portion; and a radial portion provided substantially parallel to the inward flange portion from the cylindrical portion of the metal ring. A first sealing member made of a rubber-like elastic material integrally formed with the metal ring, the lip portion being connected to the radial portion;
A support portion provided between the first seal member and the inward flange portion for supporting a root of a lip portion provided on the first seal member; and a plurality of circumferentially independent projections. An auxiliary metal ring having
A second sealing member made of a resin material having a clamped portion clamped between the inward flange portion of the metal ring and the auxiliary metal ring, and a lip portion bent in the axial direction from the clamped portion. Prepare,
A pump screw for feeding a fluid to a sealing side is provided on a sliding surface of a lip portion provided on the first seal member, and a fluid is also provided on a sliding surface of a lip provided on the second seal member on a sealing side. A sealing device provided with a pump screw for feeding pressure. 2. The sealing device according to claim 1, wherein a plurality of protrusions are provided on a contact surface of the inward flange portion with the second seal member. 3. The pump screw provided on the sliding surface of the lip provided in the second seal member has an inclination angle of 35 to 75 degrees with respect to the shaft, and the depth of the screw is greater than 0 and 75% of the thickness of the lip. The sealing device according to claim 1, wherein: Sealing device according to claim 1, 2 or 3, characterized in that a communicating portion communicating with said first sealing member and the second sealing member to said auxiliary metal ring.

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