JP2002206645A - Sealing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing device having good reliability capable of keeping pump quantity due to the guide blade pump action of a guide blade part even if the sliding surface of a seal lip wears away. SOLUTION: The atmospheric side inclined surface of the seal lip is provided with a plurality of guide blade projections inclined to the tip edge of the seal lip from a position at a fixed distance without contacting the tip edge of the seal lip not to cause a turn-up phenomenon at the tip edge of the seal lip to be higher than before to increase the pump quantity.

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 for a rotary shaft sealing portion of various devices.

[0002]

2. Description of the Related Art Conventionally, as this type of sealing device, there is one shown in FIG. 2A, for example. That is, the sealing device 100
Are mounted between a housing 101 and a rotating shaft 102 which are mounted concentrically and relatively rotatably.

The sealing device 100 includes an annular seal body 104 fitted and fixed in a shaft hole 103 of a housing 101,
A seal lip 106 and a lip portion 105 having a dust lip 107 are provided integrally on the inner peripheral side of the seal main body 104.

[0004] As shown in an enlarged view in FIG. 2 (b), a guide vane portion that performs a guide vane pump action by relative rotation with respect to the rotary shaft 102 is provided on a sliding surface of the seal lip 106 with the rotary shaft 102. 108 are provided to improve the sealing performance.

[0005]

However, in the case of the above-mentioned prior art, when the wear of the seal lip 106 progresses, the guide vane portion 108 also wears out, and the pump amount by the guide vane pump action becomes smaller than that in the initial state. Greatly reduced. In addition, if the height of the guide blade projection 109 of the guide blade portion 108 is increased, the pumping amount due to the guide blade pump action is increased. Leakage of the sealed liquid to the atmosphere side occurs.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art. It is an object of the present invention to provide a pump pump by a guide vane pump action of a guide vane even when a sliding surface of a seal lip is worn. Another object of the present invention is to provide a highly reliable sealing device for maintaining the sealing performance.

[0007]

In order to achieve the above object, the present invention seals an annular gap between two members which rotate concentrically relative to each other, and is slidable with respect to one member. In a sealing device having a seal lip which comes into sealing contact with the seal lip, a predetermined distance is formed without contacting the tip edge of the seal lip, which does not cause the phenomenon that the tip edge of the seal lip does not roll up on the inclined surface on the atmosphere side of the seal lip. A plurality of guide vane projections that are inclined relative to the leading edge of the seal lip from a position where the pump lip is increased in comparison with the related art.

Therefore, the height of the guide blade projection is increased by increasing the height of the guide blade projection, because the guide blade projection is not in contact with the leading edge of the seal lip, and the pumping amount is increased by the guide blade pump operation. I have. Since there is no guide blade projection on the sliding surface of the seal lip, even when the sliding surface is worn, the pump amount by the action of the guide blade pump can be maintained without change.

[0009]

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the dimensions of the components described in this embodiment,
The material, shape, relative arrangement, and the like are not intended to limit the scope of the present invention only to them unless otherwise specified.

The sealing device according to the present embodiment is mounted between a housing that is rotatably mounted concentrically with respect to one another and a rotating shaft as one member.

As in the prior art, the sealing device has an annular seal body fitted and fixed in a shaft hole of the housing, a lip integrally provided on the inner peripheral side of the seal body,
It is composed of

Next, the seal lip of the lip portion, which is a feature of the present invention, will be described in detail with reference to FIG.

FIG. 1A is an enlarged view showing an enlarged lip portion of the sealing device according to the embodiment of the present invention.
(B) is a figure which expands and shows the guide blade part of the atmosphere side inclined surface of a seal lip.

In FIG. 1 (a), a lip portion 1 is provided with a sealing lip 2 for preventing leakage of a sealing liquid while sliding on a rotating shaft.
And a dust lip 3 for preventing intrusion of external dust.

A spring 4 is provided on the outer periphery of the seal lip 2 to increase the force for pressing the seal lip 2 against the rotating shaft.

In the present embodiment, the dust lip 3
Is a non-sealing target atmosphere side A, and a sealing target liquid side O for sealing a liquid to be sealed, such as oil, water, or a chemical, is provided above the sealing lip 2.

On the sliding surface of the seal lip 2 with the rotary shaft, there is provided a guide blade portion 5 which performs a guide blade pump action by relative rotation with the rotary shaft.

As shown in FIG. 1B in which the guide blade portion 5 is enlarged, the setting of the plurality of guide blade projections 6 is performed only by preventing the leading edge of the seal lip 2 from rolling up as described above. Satisfies the following three conditions: a position at a certain distance without contacting the leading edge of the seal lip 2, an inclination with respect to the leading edge of the seal lip 2, and a higher position to increase the pump amount than before. That is what we are doing.

The numerical values satisfying the above three conditions are considered from the embodiment of the guide vane projection 109 of the prior art.
The constant distance to be clarified is 0.4 mm or more, the angle of inclination is in the range of 20 ° to 70 °, and the height is 0.6 mm or more.

In the seal lip having the above-described guide blade portion 5, even if the seal lip 2 is worn, the pump amount does not change. When the wear to a certain distance to be made progresses, the guide lip projection 6 starts to wear together with the wear of the seal lip 2, but at this time, the leading edge of the seal lip 2 is worn and the sliding width is widened. Since the rolling-up phenomenon does not occur, the guide vane projections 6 continuously perform a pumping operation, so that the pump amount is increased, and a pump amount more preferable than the initial state can be secured and maintained.

Incidentally, as long as the sealing device is provided with the sealing lip 2 having the guide blade portion 5 of the present embodiment, various shapes of the sealing device can be applied.

[0022]

According to the present invention, a seal is formed from a position on a slope on the atmosphere side of the seal lip, which does not roll up on the leading edge of the seal lip and does not come into contact with the leading edge of the seal lip, and which has a predetermined distance from the seal lip. Guide vanes with a plurality of guide vane protrusions with the guide vane projections inclined with respect to the leading edge of the lip are made higher to increase the pumping volume than before. The pump amount by the action of the guide blade pump of the blade portion can be more preferably secured and maintained than in the initial state.

[Brief description of the drawings]

FIG. 1A is a diagram showing a lip portion of a sealing device according to an embodiment, and FIG. 1B is a diagram showing a guide blade portion on an atmosphere-side inclined surface of a seal lip.

FIG. 2A is a view showing a conventional sealing device;
FIG. 2B is a view showing a lip portion of the conventional sealing device.

[Explanation of symbols]

 1. 105 lip part 2. 106 seal lip 107 dust lip 4 spring 5 108 Guide blade 6. 109 Guide blade projection 100 Sealing device 101 Housing 102 Rotary shaft 103 Shaft hole 104 Seal body Constant distance Inclination angle Height

Claims (1)

[Claims] 1. An inner peripheral surface which slidably and sealingly contacts one of two members which are assembled so as to be relatively rotatable relative to each other,
In a sealing device having an annular seal lip having a wedge-shaped cross section having an atmosphere-side inclined surface and a liquid-side inclined surface inclined in mutually opposite directions, the atmosphere-side inclined surface of the seal lip includes:
The guide blade projection that inclines with respect to the tip of the seal lip from the position where a certain distance is left without contacting the tip of the seal lip that does not cause the phenomenon that the seal lip does not roll up A sealing device comprising: a guide blade portion having a plurality of guide blade protrusions that are raised to increase the amount of the guide blade.