JPH11210891A - Sealing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve eccentric followability of sealing in a sealing device adapted to a shaft seal part by forming a circumferencial groove on the resin-made sealing member which has a lip extended from a sandwiched portion through a bent portion, so as to extend from the sliding surface of the lip to the sandwiched portion over the bent portion. SOLUTION: This sealing device 1 for sealing a gap between a shaft 70 and a housing 80 is composed of a metal circle 20, sealing members 30 and 40. The sealing member 40 has a portion 41 sandwiched between an inward flange 22 of the metal circle 20 and a diametral portion 32 of the seal member 30, and a lip 42 axially bent from the sandwiched portion 41 through a bent portion 44. The sealing member 40 is made of resin. A pump groove 43 is formed on a sliding surface of the lip 42 against the shaft 70. The pump groove 43 is so formed that fluid is flowed to the side of sealing fluid O by relative rotation of the shaft sealing device 1 in respect to the shaft 70, to obtain pumping effect. Eccentric follwability of the sealing 40 is thus improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a sealing device used for a shaft sealing portion of various devices.

[0002]

2. Description of the Related Art Conventionally, this type of sealing device has
For example, there is a sealing device shown in FIG.

[0003] As shown in the figure, the sealing device 100 includes a shaft 2.
This seals an annular gap between the cylinder housing 00 and the cylindrical housing 300 so that fluid such as lubricating oil sealed in the sealed fluid side O does not leak to the atmosphere side A.

As a schematic configuration of the sealing device 100, a metal ring 101, a sealing member 102 made of a rubber-like elastic material formed integrally with the metal ring 101, and sandwiched between the metal ring 101 and the sealing member 102. Resin sealing member 10
And 3.

[0005] The seal member 102 includes an outer peripheral sealing portion 102b that sealingly contacts the inner peripheral surface of the housing 300, and a shaft 200.
102a, lip 102a that slides on and seals
And a radial portion 102c connecting the outer peripheral sealing portion 102b to the outer peripheral sealing portion 102b.

The seal member 103 supports the root of the lip 102a of the rubber-like elastic member 102 to prevent excessive deformation of the lip 102a.
It comes into sliding contact with 00 to exhibit sealing properties.

A groove 104 having a pump function for suppressing leakage of fluid is provided on the sliding surface side of the seal member 103.
Are formed from the lip portion 103a to the bent portion 103b.

With such a configuration, an annular gap between the shaft 200 and the cylindrical housing 300 is sealed.

[0009]

However, the groove 104 of the seal member 103 is formed only halfway through the bent portion 103b. If the groove 104 is eccentric when the shaft 200 is mounted on the sealing device 100, the seal 104 is not sealed. Excessive stress is generated in the bent portion 103b of the member 103.

When such an excessive stress is generated, as shown in FIG. 4, the groove 10b is formed at the bent portion 103b (the boundary between the lip portion 103a and the bent portion 103b in this figure).
A bend or break along 4 (P1 in the figure)
May occur.

Therefore, due to such bending or bending,
There is a concern that the contact function of the sliding surface of the lip portion 103a with the shaft 200 to prevent uneven contact and pressure deformation of the seal lip 102a of the seal member 102 may be reduced, leading to a reduction in sealing performance.

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 provide a good sealing performance by preventing a resin seal lip from being bent or broken. It is to provide a sealing device which can be used.

[0013]

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 from one end of the cylindrical portion in the inner diameter direction. A rubber portion integrally formed with the metal ring, having a radial portion provided substantially in parallel with the inward flange portion from the cylindrical portion of the metal ring, and a lip portion connected to the radial portion. A first seal member made of an elastic body, a clamped portion clamped between an inward flange portion of the metal ring and a radial portion of the first seal member, and a shaft from the clamped portion via a bent portion; A second sealing member made of resin having a lip portion extending in the direction, the second sealing member being formed from the sliding surface of the lip portion to the pinched portion beyond the bent portion. It is characterized by having a circumferential groove formed.

Thus, it is possible to improve the eccentricity followability of the second seal member, to prevent the second seal member from being bent or broken, and to exhibit good sealing performance.

[0015]

Embodiments of the present invention will be described below with reference to the accompanying 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 thereto unless otherwise specified. Absent.

FIGS. 1 and 2 show a sealing device according to an embodiment of the present invention. FIG. 1 is a schematic configuration sectional view of a sealing device, and FIG. 2 is a schematic configuration sectional view showing a second sealing member alone of the sealing device.

As shown in the figure, the sealing device 1 seals an annular gap between a shaft 70 and a housing 80 which is a cylindrical member, and a fluid such as a lubricating oil on a sealed fluid side O is supplied to the atmosphere side A. This is to prevent leakage.

The sealing device 1 generally includes a metal ring 20, a first seal member 30 formed integrally with the metal ring 20, and a second seal member 40 sandwiched between the metal ring 20 and the first seal member 30. It is composed of

The metal ring 20 has a cylindrical portion 21 which is arranged concentrically with the shaft 70 and the housing 80 when assembled, and an inner diameter from one end of the cylindrical portion 21 (in this embodiment, the atmosphere side portion in the assembled state). Direction (direction toward axis 70)
And an inward flange portion 22 that bends inward.

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 in parallel with the inward flange portion 22 from the covered portion. It has a radial portion 32 provided and a lip portion 33 connected to the radial portion 32, and is formed of a rubber-like elastic body.

When assembling the sealing device 1, the outer peripheral portion 31 of the first seal member 30 comes into sealing contact with the inner periphery of the housing 80, and a spring ring that applies a radially compressive force to the outer periphery of the lip portion 33. 5 is attached, and the tip of the lip portion 33 slides on the outer peripheral surface of the shaft 70, whereby a fluid such as oil on the sealed fluid side O can be sealed.

The lip portion 33 has, for example, a U-shape so that a fluid can flow to the sealed fluid side O even if the sealing device 1 rotates in any direction with respect to the shaft 70. It is also possible to provide a pump screw 34 that exerts an effect.

The second seal member 40 includes an inward flange portion 22 of the metal ring 20 and a radial portion 32 of the first seal member 30.
Between the clamped portion 41 and the clamped portion 41
Lip portion 4 that bends in the axial direction from bending portion 44 through bending portion 44
2 and is made of resin (such as PTFE).

When the shaft 70 is not inserted, the bent portion 44 is not bent as shown in FIG. 1 and has a substantially flat washer shape.
As a result, the inner edge bends while expanding its diameter along the outer peripheral surface of the shaft 70, and the lip portion 42 is arranged to be slidable on the outer peripheral surface of the shaft 70.

FIG. 1 shows a case where the inner edge is enlarged in diameter to form the lip portion 42.

The tip of the lip 42 supports the root of the lip 33 of the first seal member 30 to prevent excessive deformation of the lip 33 even when a high pressure is applied to the lip 33. In addition, the sealing property of the lip portion 33 is maintained.

A pump groove 43 as a circumferential groove is also provided on the sliding surface of the lip portion 42 on the shaft 70.

The pump groove 43 is provided so that the sealing device 1
Fluid relative to the sealed fluid side O
It has a structure that exerts a pump effect such as flowing to the outside.

The pump groove 43 is provided so that the sealing device 1
In contrast, when applied to a location that normally rotates only in one direction and does not rotate much in the other direction, a helical shape that efficiently exerts a pumping effect on rotation in one direction In the case where the present invention is applied to a portion that rotates in both directions, it is also preferable to use a number of annular grooves that appropriately exert a pumping effect for any rotation. is there.

Further, as shown in FIG.
Is moved from the lip portion 42 beyond the bent portion 44 to the pinched portion 41
Is formed up to. By providing the pump groove 43 up to the pinched portion 41, it is possible to improve the eccentricity followability of the second seal member 40, and to prevent the second seal member from being bent or bent by stress due to eccentricity at the time of mounting. Thus, good sealing performance can be exhibited.

On the other hand, the depth d of the pump groove 43 is
2 is preferably set to 75% or less of the plate pressure. For example, when the plate thickness t of the lip portion 42 is 1.0 mm, the pitch p of the pump groove 43 is 0.3 mm, and the inclination a is 35 to 75.
When the degree and the depth d are set to 0.5 mm, it is recognized that excellent pumping effect and flexibility are exhibited.

Further, as shown in the drawing, the position where the portion to be bent from the held portion 41 toward the lip portion 42 is
By bending at the outer diameter side than the inner diameter formed by the end face of the inward flange portion 22 of 0,
That is, the position where the second seal member 40 is sandwiched by the first seal member 30 is set to the inward flange portion 2 of the metal ring 20.
By stopping the lip portion 42 on the outer diameter side from the holding position of the lip portion 2, the eccentric followability of the lip portion 42 can be improved.

The inward flange portion 22 of the metal ring 20
By providing the rotation preventing projection 6 on the contact surface of the second seal member 40 with the pinched portion 41 in the above, the co-rotation of the second seal member 40 with the shaft 70 can be prevented.

According to 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 80 side, and the first sealing member 30 is sealed on the shaft 70 side. Is sealed by the lip portion 33 of the helmet.

The fluid leaking from the lip portion 33 can be returned to the sealed fluid side O by a pump screw provided on the lip portion 33.

When the gas leaks from the lip portion 33 to the atmosphere side A, it is properly returned to the sealed fluid side O by the pump groove 43 provided in the second seal member 40.

Further, since the tip of the lip portion 42 supports the root of the lip portion 33 of the first seal member 30, the pressure deformation of the lip portion 33 is suppressed, and the lip portion 33 is prevented from moving or turning up, so that it is stable. The sealing performance can be maintained.

The second seal member 40 is provided with the pump groove 43 up to the to-be-clamped portion 41, so that the eccentricity followability can be improved. Irregular bending and bending of the member can be prevented, and good sealing performance can be exhibited.

[0039]

As described in the embodiment of the present invention, it is possible to improve the eccentricity followability of the second seal member, to prevent the second seal member from being bent or broken, and to improve the eccentricity. A sealing device exhibiting sealing performance is obtained.

[Brief description of the drawings]

FIG. 1 is a schematic configuration sectional view of a sealing device according to an embodiment of the present invention.

FIG. 2 is a schematic sectional view showing a second sealing member alone of the sealing device according to the embodiment of the present invention.

FIG. 3 is a schematic configuration sectional view showing a state where a sealing device according to a conventional technique is assembled.

FIG. 4 is a diagram showing a problem of a sealing device according to the related art.

[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 40 Second seal member 41 Interposed part 42 Lip part 43 Pump groove 44 Bend part 70 Shaft 80 Housing O Seal Fluid side A Atmospheric side a Groove inclination d Groove depth p Groove pitch t Lip plate thickness

Claims (1)

[Claims] 1. 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 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 body integrally formed with the metal ring, the first sealing member having a radial portion, a lip portion connected to the radial portion, and an inward flange portion of the metal ring. A second sealing member made of a resin having a sandwiched portion sandwiched between the first sealing member and a radial portion of the first sealing member, and a lip portion extending in the axial direction from the sandwiched portion via a bent portion. The sealing device according to claim 1, wherein the second sealing member includes a circumferential groove formed from the sliding surface of the lip portion to the pinched portion beyond the bent portion.