JPS6192370A - Emergency shaft sealing device - Google Patents

Abstract

PURPOSE:To enable a sealing to certainly restore its configuration prior to diameter shrinking deformation even though the sealing can not recover well with its own restoring force, by providing a means for forcing the sealing to restore its configuration prior to diameter shrinking deformation when pressurized liquid is restrained from acting on it. CONSTITUTION:A vaccum suction pipe line 7 provided with a suction open/close valve 8 connected to a vacuum suction mechanism such as a vacuum pump etc. not shown in the figure, is connected to a main pipe line 4. It supply of pressurized fluid is shut off and a suction open/close valve 8 is opened in this constitution, the inside of space 10 is evacuated to maintain low pressure. Sucking action based upon such pressure reduction forces a sealing line 9 to restore its configuration prior to diameter shrinking deformation.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an emergency shaft sealing device that acts as a shaft seal in place of the main shaft seal 2 for normal operation in an emergency such as when an abnormality occurs in the main shaft seal 2 used for normal operation. It is.

[Conventional technology]

Various configurations of this type of emergency shaft sealing device have been proposed in the past, but one that is most suitable for emergency use from a functional and structural standpoint is the one disclosed in Japanese Patent Application No. 58-211439. There is something.

This emergency shaft seal device has one
An annular housing groove is formed along the outer circumference of the rotating shaft, and a seal ring made of an elastic material and having an inner diameter larger than the outer diameter of the rotating shaft is loosely fitted into the housing groove without contacting the rotating shaft. 1 by deforming the seal ring to reduce its diameter by the pressure of pressurized fluid applied to its outer circumference.
It is configured so that it can be brought into pressure contact with the rotating shaft to perform shaft sealing.

According to this emergency shaft sealing device, when an abnormality occurs in the main shaft sealing device, pressurized fluid such as air is applied to the outer circumferential side of the seal ring to prevent the main shaft sealing device from being damaged. Instead, the shaft can be sealed, and when the abnormality is corrected, the supply of pressurized fluid is stopped, and
A space surrounded by the inner surface of the housing groove and the outer periphery of the seal ring is opened to the atmosphere to seal the seal ring.

The state before 1ii diameter deformation due to its own elastic restoring force! In other words, the rotary shaft is returned to a non-sealed state without contact with the rotating shaft.

[Problem that the invention seeks to solve]

However, in the case of such a conventional configuration, the return of the seal ring to the non-shaft sealing state after repair when the cause of the abnormality has been removed is as follows:
The elastic restoring force of the seal ring itself is used, and since the seal ring is usually tightly installed in the housing groove to avoid leakage of pressurized fluid, it naturally reduces the frictional resistance during one operation. As a result, this return operation lacks smoothness, resulting in the inconvenience that the return operation cannot always be performed quickly and reliably.

In addition, this return operation is greatly affected by the liquid to be sealed at the point of use and its environmental conditions, resulting in problems such as loss of reliability. The present invention provides an emergency shaft sealing device that solves these problems.

[Means for solving problems]

In other words, the emergency shaft seal of the present invention! In particular, 1ffi is provided with a return means for forcibly returning the seal ring to the state before diameter reduction deformation when no pressurized fluid is applied. ′ [Function] According to this configuration, when the shaft sealing by the emergency shaft sealing device is no longer required, when the supply of pressure fluid is stopped,
Even when the seal ring cannot be returned satisfactorily only by its own elastic restoring force, the return means reliably returns it to the state before the diameter reduction deformation.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

In the illustrated emergency shaft sealing device, 1 is a rotating shaft, 2 is a seal housing, and an annular housing groove 3 is formed in the inner circumference of the seal housing 2 along the outer circumferential surface of the rotating shaft 1. There is.

In the housing yt3, a seal ring 9 made of an elastic material and having a circular cross section and whose inner diameter is larger than the outer diameter of the rotating shaft 1 is loosely fitted onto the rotating shaft 1 without contacting it! It is housed in E. In this embodiment, the main body portion 9a of the seal ring 9 is made of F4 material, which has good sealing performance against the shaft sealing surface of the rotating shaft l, and has good elastic restoring force of the member itself, and has a housing groove. Both side portions 9b, 9b in contact with the inner surface of 3
In addition, a soft material with as low sliding friction resistance as possible is used, and each of these materials is integrally formed to have a composite cross-sectional structure.

Moreover, in the space lO surrounded by the inner surface of the housing i43 and the outer circumference of the seal ring 9, there is a main pipe -4.
The main pipe 4 is connected to a pressurized fluid supply pipe 5 equipped with a pressurized on-off valve 6 connected to an appropriate pressurized fluid supply source, such as a compressor (not shown). When the on-off valve 6 is opened, pressurized fluid such as air is supplied to the space lO, and the diameter of the seal ring 9 is reduced to bring it into pressure contact with the rotating shaft l, thereby sealing the shaft. (See Figure 2!11).

The emergency shaft sealing device configured as described above further includes a return means for forcibly returning the seal ring 9 to the non-shaft sealing state (the state shown in FIG. 1) before the diameter reduction deformation. It is provided.

That is, in this embodiment, the return means is a vacuum suction mechanism connected to the space 10, and is a vacuum suction mechanism equipped with a suction on/off valve 8 connected to a vacuum suction device (not shown) such as a vacuum pump. A suction pipe line 7 is connected to the main pipe line 4.

According to such a vacuum suction mechanism, when the supply of pressurized fluid is stopped by the pressurization on-off valve 6 and the suction on-off valve 8 is opened, the inside of the space IO is vacuum-suctioned and the pressure is reduced. Due to the suction action caused by this reduced pressure, the seal ring 9
is forced to return to the state before diameter reduction deformation (first
(see figure).

Therefore, in the emergency shaft seal device configured as described above, the shaft seal 41 of the main shaft seal device! When the seal ring 9 is repaired and the emergency shaft seal is no longer needed, the seal ring 9 can be reliably returned to the non-shaft sealing state before the diameter reduction deformation by the suction action from the vacuum suction pipe 7. You can prepare for the first emergency.

Further, in the case of this embodiment, since the seal ring 9 has a composite cross-sectional structure, the main body portion 9a made of a hard material with good sealing performance and elastic restoring force at the center allows for emergency shaft sealing. Therefore, an effective shaft sealing effect can be obtained.
Moreover, at the time of return, an effective return action can be obtained in addition to the above-mentioned depressurization and suction action, and the both side portions 9b, 9b made of a soft material with low sliding frictional resistance on both sides in contact with the inner surface of the housing groove 3 The compatibility between the seal housing 2 and the seal ring 9 is further ensured, and the opening and closing operations thereof can be performed more smoothly.

Note that the return means for forcibly returning the seal ring 9 is not limited to the vacuum suction mechanism as in the above embodiment, but may be constructed of an elastic member that elastically presses the seal ring 9 in the direction of diameter expansion. Good too.

For example, as shown in tiS31g, a garter spring 11 is provided on the inner peripheral surface side of the seal ring 9, and the seal ring 9 is applied with its own elastic force.
Al may be used so that it can be returned to the non-shaft-sealed state (the state indicated by the dashed line in FIG. 3) before the diameter reduction deformation with the elastic force of .

In this case, the seal ring 9 has a U-shaped cross section,
The spring 11 is disposed within the inner peripheral recess 9c of the seal ring 9 so that the garter spring 11 does not interfere with the sealing performance of the seal ring 9.

[Effects of the Invention] According to the present invention, when the emergency shaft sealing by the seal ring is no longer required, the seal ring can be used not only by its own elastic restoring force but also by an elastic member such as a vacuum suction mechanism or a garter spring. Strength 1 of the return means: 1) Since it is possible to forcibly return wj diameter deformation to the non-shaft sealing state of γi by using the acting force, emergency shaft seal repair can be performed without being affected by the liquid to be sealed or its environmental conditions. The subsequent return operation of the seal ring can be performed smoothly, quickly, and reliably.In particular, the center part of the seal ring is made of a hard material that has good sealing performance against the shaft sealing surface and the elastic restoring force of the member itself. The main part and the print***m
By creating a cross-sectional shape that is made of a soft material with as little resistance as possible and an integral composite of both side parts, the effect can be further improved and malfunctions and sealing failures can be prevented. This makes it possible to easily provide an extremely reliable device configuration despite its simple configuration.

[Brief explanation of the drawing]

1 and 2 are longitudinal sectional side views showing an embodiment of the emergency shaft sealing device according to the present invention, in which FIG. 1 shows the non-shaft sealing state before diameter reduction deformation of the seal ring, and FIG. The figure shows the shaft sealed state after the diameter reduction deformation, and FIG. 3 is a longitudinal sectional side view similar to the above figure showing another embodiment. 1... Rotating shaft 2... Seal housing 3... Accommodation groove 5... Pressurized fluid supply line 6... Pressure opening/closing valve 7... Vacuum suction line 8... Suction opening/closing Valve 9...Seal ring 9a...Main part 9b...Both sides 9C...Inner periphery recess 10...Space 11...Garter spring patent applicant Agent of Nippon Pillar Kogyo Co., Ltd.
Patent Attorney Takashi Suzue - Kayu 1 Ward Hook 3 Diagram

Claims (4)

[Claims] (1) An annular accommodation groove is formed in the inner circumference of the seal housing along the outer circumference of the rotating shaft, and a seal ring made of an elastic material is placed in this accommodation groove, the inner diameter of which is larger than the outer diameter of the rotating shaft. The seal ring is accommodated in a loosely fitted state without contact with the rotating shaft, and the seal ring is brought into pressure contact with the rotating shaft by reducing its diameter by the pressure of pressurized fluid applied to the outer circumference of the seal ring. An emergency shaft sealing device configured to perform sealing, characterized in that a return means is provided for forcibly returning the seal ring to the state before diameter reduction deformation when no pressurized fluid is applied. Emergency shaft sealing device. (2) The return means is a vacuum suction mechanism connected to a space surrounded by the inner surface of the housing groove and the outer peripheral surface of the seal ring. emergency shaft sealing device. (3) According to claim 1, the return means is an elastic member provided on the inner peripheral surface side of the seal ring and elastically presses the seal ring in a radially expanding direction. emergency shaft sealing device. (4) As for the cross-sectional structure of the seal ring, the main body portion at the center is made of a hard material that has good sealing performance against the shaft sealing surface and the elastic restoring force of the member itself, and both side portions in contact with the inner surface of the housing groove. Claims 1, 2, or 3 are characterized in that they are constructed by using soft materials with as low sliding friction resistance as possible, and by integrally combining these materials. The emergency shaft sealing device described in .