JPH0422133Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a gland packing that seals between a housing of a pump or other equipment and a shaft on the inner circumference thereof.

[Conventional technology]

Conventionally, as a type of shaft circumferential sealing device, as shown in FIG. It is suitably compressed by a gland 6 fixed to the end face 4 of the opening of the stuffing box 3 via a gland bolt 5, and is pressed against both the inner peripheral surface of the housing 1 and the outer peripheral surface of the shaft 7 in the stuffing box 3. Gland packing 17 that performs sealing is widely used.

[The problem that the idea aims to solve]

The sealing power of this type of gland packing 17 is
Gland 6 adjustable by gland bolt 5
On the other hand, if the load is excessive, the contact force with the shaft 7 becomes large, which may cause problems such as abnormal wear or seizure of the shaft 7. However, it is currently very difficult to determine whether this pressure force is appropriate or not, as it relies on the experience and intuition of the people who install the packing 17. Moreover, if the gland packing 17 is installed in a location that cannot be seen from the outside, the pressure against the shaft 7 and the housing 1 may decrease due to deterioration of the gland packing 17 or wear of the shaft 7, causing leakage. This could not be confirmed and there was a risk of a large amount of leakage.

[Means to solve the problem]

Therefore, in order to solve the above problem, the gland packing according to the present invention has a configuration in which a pressure-sensitive sensor is attached that is connected to an external circuit having a monitoring device and opens and closes the circuit according to the load applied to the packing. And so.

[Effect]

In this configuration, when a predetermined load is applied to the gland packing by tightening the gland,
The pressure-sensitive sensor attached to the packing senses the load and makes the circuit conductive, and when the pressure falls below a predetermined pressure, it makes the circuit non-conductive. performs the action.

〔Example〕

Next, the present invention will be explained based on an embodiment shown in FIGS. 1 to 3.

The gland packing 8 according to this embodiment includes, on the outer peripheral surface of the gland packing main body 8a, annular thin electrode plates 10 and 11 made of a conductive fiber material that face each other in the radial direction and are easily flexibly deformed, and both electrode plates. 1
An insulating spacer 12 is interposed between the electrode plates 10 and 11 at both ends in the axial direction, and an insulating outer skin 13 made of elastic vinyl chloride or the like encloses the electrode plates 10 and 11 and the insulating spacer 12. As shown in FIG. 2, the electrode plates 10 and 11 are equipped with an external display lamp 15 as a monitor device, and a circuit 14 having a power source 16 for lighting the display lamp 15. Connected. Other parts are the same as those shown in FIG. 4 described above.

In the above configuration, when the gland 6 is tightened with the gland bolt 5, the gland packing 8 packed in the stuffing box 3 is compressed, and the reaction force applies a load in the radial direction to the gland packing main body 8a. occurs. Therefore, the inner circumferential surface of the gland packing main body 8a comes into pressure contact with the outer circumferential surface of the shaft 7, and the pressure-sensitive sensor 9 on the outer circumference of the main body 8a also receives the radial load, so that the outer circumferential surface of the elastic outer skin 13 The electrode plate 11 on the inner circumference side of the electrode plates 10 and 11 of the pressure-sensitive sensor 9, which is in pressure contact with the inner circumference of the housing 1, is deformed by receiving the load through the outer skin 13, as shown in FIG. , when the load reaches a predetermined level, it comes into contact with the electrode plate 10 on the outer peripheral side and brings the circuit 14 into a conductive state.
The indicator lamp 15 lights up.

Furthermore, since the load necessary for the conduction can be arbitrarily changed depending on the rigidity of the electrode plates 10 and 11 and the thickness of the insulating spacer 12, the load applied to the gland packing 8 in the radial direction by tightening the gland 6 When the load reaches an optimum level, it may be configured to sense pressure and conduct.

In the above configuration, when the pressure contact force of the gland packing 8 against the shaft 7 and the housing 1 decreases over time due to wear of the shaft 7, deterioration of the gland packing main body 8a, etc., the pressure sensor 9 is affected accordingly. Since the applied load also becomes smaller, the electrode plates 10 and 11 are separated as shown in FIG. 3, the circuit 14 is opened, and the indicator lamp 15 is turned off. Therefore,
In this case, if the gland 6 is further tightened until the indicator lamp 15 lights up again, the appropriate load will be restored to the gland packing 8, and good sealing performance can be restored.

In this embodiment, the display lamp 15 is used as an external monitoring device, but instead of this, for example, when the circuit 14 is in a conductive state (pressure sensor 9 is ON), it is turned off, and the circuit 14 is turned off (non-conductive). Using a drive circuit having an electromagnetic relay that turns ON when the pressure sensor 9 is in the OFF state, a buzzer or display connected to the drive circuit is used when the pressure contact force applied to the gland packing 8 is below a predetermined value. The alarm may be issued by driving a lamp or the like.
In addition, the pressure sensor 9 is connected to the gland packing main body 8.
It is also possible to have a configuration in which the pressure sensor 9 is buried in the ground packing body 8a, and the pressure sensor 9 is also turned on according to the load of the gland packing body 8a.
It may be anything that turns off, and is not particularly limited to what is shown in the figure.

[Effect of idea]

As described above, according to the present invention, the gland packing is equipped with a pressure-sensitive sensor that turns on and off depending on the magnitude of the load applied to the gland packing, so that the appropriate load (sealing force) is applied to the gland packing.
It is now possible to monitor from the outside whether or not the sealing force is applied, making it possible to install the gland packing with an appropriate load without relying on the operator's skill or intuition, and to prevent the sealing force from decreasing over time. Since it can be ascertained, it is possible to take appropriate measures to prevent leakage by retightening the gland.

[Brief explanation of the drawing]

Fig. 1 is a half-cut cross-sectional view showing an embodiment of the present invention under proper load, Fig. 2 is a schematic circuit diagram, Fig. 3 is a half-cut cross-sectional view when the load is reduced, and Fig. 4 is a conventional example. FIG. 1...Housing, 2...Shaft hole, 3...Stuffing box, 5...Gland bolt, 6...
Grand, 7...Axis, 8...Grand Patsukin,
8a...Gland packing body, 9...Pressure sensor, 10, 11...Electrode plate, 12...Insulating spacer, 13...Insulating outer cover, 14...Circuit, 15...
Indicator lamp (monitor device).

Claims (1)

[Scope of utility model registration request] An external circuit having a monitor device is connected to a gland packing compressed by a gland between a stuffing box formed in the shaft hole of the housing and a shaft inserted into the inner periphery of the shaft hole. 1. A gland packing comprising a pressure-sensitive sensor that opens and closes the circuit according to a load applied to the gland packing.