JPS5913353Y2 - Citrus motor pump - Google Patents

Description

[Detailed description of the invention] The present invention relates to an improvement of a submersible motor pump, in which water leaking into the motor casing is actively guided to the water tank to prevent water leaking into the winding chamber from the shaft penetration part. It is characterized by being constructed to prevent infiltration.

A submersible motor pump has a structure in which a motor is housed in a casing and a pump is directly connected below the motor, and the entire casing or a part of the casing is immersed in water.

The above motor uses a sealing mechanism such as a mechanical seal between the motor shaft and the casing to prevent water leakage, but in reality, during use, the motor bearing and motor There is a problem in that water leaks into the winding chamber and destroys or nearly destroys the electrical insulation of the motor windings.

Submersible motor pumps assume that there is water leakage from the shaft penetration, so a water tank is installed below the winding room to store the leakage water, and when the water reaches a predetermined level, the submersible motor pump is pulled up and drained. There is something configured to do this.

The invention described in Japanese Utility Model Application Publication No. 49-29411 is an example of this type of submersible motor pump, but since the water tank in this structure is extremely small, even a small amount of water leakage will issue an alarm. Since the water must be drained after a short period of operation, operation is complicated and there is a high risk of damaging the motor part.

In addition, another device described in Japanese Utility Model Application Publication No. 49-29410 is configured to send leaked water into the water tank in the casing through the bearing, which may destroy the bearing or shorten the life of the bearing. The problem is that it is significantly shortened.

The present invention was developed to eliminate the drawbacks of the conventional device, and is characterized by a structure that prevents water from leaking into the bearing and sends leaked water into the water tank. There is.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a longitudinal cross-sectional view showing the first embodiment of the present invention.
is a motor rotor, and the shaft 2 passing through the center is connected to the bearing 3,
4, it is rotatably supported.

A motor stator 5 is provided outside the motor rotor 1 , and the motor stator 5 is supported in a casing 6 .

Reference numeral 7 denotes a lid, through which a power supply wire 8 passes airtightly, and a hanging ring 9 is provided at the center of the lid.

A lower casing 6a is provided below the casing 6, and a pump casing 10 of the pump 10 is provided below this.
a is supported.

Further, an impeller 10b is fixed to the lower end of the shaft 2, and as the motor rotor 1 rotates, water is sent in the direction of the arrow in FIG.

An annular projecting plate 11 is provided in the middle portion of the casing 6a, and a bearing support 12 is provided using this.

A bearing 4 is fitted and supported in a cavity at the center of the bearing support 12, and a lid 13 presses down the bearing 4, and a backing 14 is used to prevent water leakage between the bearing 4 and the shaft 2.

On the other hand, an annular plate 15 is provided between the casing 6 and the lower casing 6a, and a water reservoir 16 is provided between the projecting plate 11 and the annular plate 15.
At the same time, a gap 1 is formed between the lid 13 and the annular plate 15.
7 is formed so that water leaking from the winding chamber flows into the water storage chamber 16.

Further, the bearing support 12 and the lid 7 include a sealing device,
For example, water that is about to leak from a double seal type mechanical seal 10 with a small amount of leakage transmitted to the motor side through the shaft 2 is sealed.

On the outer periphery of these mechanical seals 19, 20, a liquid reservoir chamber, for example, an oil reservoir chamber 16a, which is generally provided when using the double seal type mechanical seals 19, 20, is located on the lower surface of the bearing support 12, the upper surface of the lid 7b, and the upper surface of the lid 7b. It is formed by a casing 6a.

Since the mechanical seals 19 and 20 leak water, although the amount of leakage is very small, the mechanical seals 19 and 20 are connected from the pump 10 side to the motor side.
Water leaking through the shaft 20 is guided to the water reservoir 16 through a passage 23 that communicates the outer circumference of the shaft 2 with the water reservoir 16.

Water leaking to the motor side through the shaft 2 is transferred to the bearing support 12.
Inside, the passage 23 is opened by the centrifugal action caused by the rotation of the shaft 2.
Since the water passes through the shaft and reaches the inside of the water storage chamber 16, the water does not reach the bearing 4, but depending on the conditions, an auxiliary pump 22 may be provided on the shaft 2.

In this case, a bearing 4 supporting the shaft 2 is used as shown in FIG.
An auxiliary pump 22 is provided between the auxiliary pump and the mechanical seal 19, and the auxiliary pump pushes water downward into the passage 23.
What is necessary is just to structure so that water may be sent into the water immersion chamber 16 through.

FIG. 2 is a side sectional view showing an example in which a screw pump is used as the auxiliary pump 22, in which the shaft 2 is provided with a screw portion 22 a, and the screw pump is connected between the screw portion 22 a provided on the shaft 2 and the wall surface 22 b of the through hole of the bearing support 12 facing the screw portion 22 a. By driving the shaft 2 in the direction of arrow A, a downward flow is generated in the direction of arrow B, and then the water is moved in the direction of arrow C to send the water into the submergence storage chamber 16. There is.

While the auxiliary pump 22 is in operation, water that attempts to leak from the upper shaft penetrating portion of the auxiliary pump always creates a downward flow so as to be prevented from leaking, thereby preventing water from leaking toward the bearing 4. can be prevented.

FIG. 3 shows another auxiliary pump, in which an impeller 24 for a centrifugal pump is provided on the shaft 2 and the water is pumped into the immersion chamber 16 through a passage 23.

The water thus sent into the flooded reservoir chamber 16 eventually accumulates and raises the water level.

This water level is detected by a liquid level detection device provided on the annular plate 15, for example, a water leak detector 18 as shown in the figure.The detection surface of the water leak detector 18 is as shown in FIG. It is set to be located above the lower surface of the bearing 4 by δ.

Therefore, the height from the bottom of the water storage chamber 16 to the detection surface of the water leakage detector 18 can be increased, so even if the liquid storage chamber (oil storage chamber) 16a is provided within a limited space, the water can be further flooded. The effective volume within the reservoir chamber 16 can be increased.

As a result, due to the action of the double-seal type mechanical seals 19 and 20 that have an extremely small amount of leakage, and because the effective area of the water reservoir chamber 16 can be increased, the water reservoir chamber 16
Since it takes longer to fill up the water inside the tank, the number of times the pump has to be pulled out of the water to drain water can be reduced.

Further, since the distance between the water outlet of the passage 23 and the detection surface of the lower water leakage detector 18 is increased, malfunction of the water leakage detector 18 can also be prevented.

When the liquid level in the water storage chamber 16 rises as described above and reaches the water leak detector 18, an alarm is issued, so the operator must raise the submersible pump above the water surface and open the drain tap 24. Then drain it.

Note that 21 is a backing provided to prevent water from flowing into the bearing 4 side.

Note that the oil reservoir chamber 16 between the pump 10 and the flooded reservoir chamber 16
The water mixed in a can be discharged together with the oil by operating the tap 25.

FIG. 4 is a longitudinal sectional view showing another embodiment, in which a wall plate 6b is provided on the upper part of the lower casing 6a, and the annular plate 1 in FIG.
It has the same effect as 5.

This wall plate 6b is provided with a hole 26 to allow water leaking into the winding chamber to flow into the water storage chamber 16.

The lower part of the bearing support body 12 a that supports the bearing 4 is the support plate 1
2b, a groove or slit H2C is provided on the joint surface of both so that the water sent out by the auxiliary pump 22 is sent into the water storage chamber 16.

Since the present invention is configured as described above, it has the following effects.

(a) Water immersion chamber 16 between the liquid reservoir chamber 16a and the dry motor
Because of the partitioned structure, the effective volume inside the water storage chamber 16 can be increased despite the limited space.
As a result, it takes longer to fill the water reservoir chamber 16 with water, so the number of times the pump is lifted out of the water to drain water can be reduced, and work efficiency can be significantly improved.

(b) Also, the sealing device 19 and the bearing 4 at the bottom of the motor shaft
Since a passage 23 is formed between the motor shaft outer circumference and the water reservoir chamber 16, water accumulated on the motor shaft outer circumference passes through the passage 23 and enters the water reservoir due to the centrifugal action caused by the rotation of the motor shaft 2. Since the bearing 4 is actively sent into the chamber 16, the bearing 4 does not get wet with water, so there is less corrosion or wear, and the durability of the motor can be increased.

In particular, submerged motor pumps are often used while immersed in muddy water or the like for a long period of time, but according to the present invention, since the bearing 4 is protected from water immersion, it is extremely easy to handle.

(C) A liquid level detection device 18 is installed in the water storage chamber 16 to detect the liquid level when the liquid level in the water storage chamber 16 reaches above the lower surface of the bearing 4 at the bottom of the motor shaft. The effective volume within the chamber 16 can be increased, and the bearing 4 can be quickly detected before it is submerged in water.

(d) Furthermore, even if the seal device is a mechanical seal, the amount of leakage cannot be completely reduced to zero, but there is a very small amount of leakage.

Therefore, in the case of conventional detection devices capable of detecting such extremely small amounts of leakage, there was a problem that the detection operation was performed frequently and it was easy to malfunction, but compared to this, the liquid level of the present invention is The detection device 18 detects the liquid level in the water storage chamber 16 as described above when it reaches above the lower surface of the bearing 4 at the lower part of the motor shaft, so the detection operation is not performed frequently, and therefore the liquid level This can effectively prevent malfunction of the detection device 18.

[Brief explanation of drawings]

The figures show an embodiment of the present invention. Figures 1 and 4 are longitudinal cross-sectional views of a dry submersible pump, and Figures 2 and 3 are a built-in device for preventing water intrusion below the bearing of the pump. FIG. 3 is a vertical cross-sectional view showing an example of an auxiliary pump. DESCRIPTION OF SYMBOLS 1... Motor rotor, 2... Shaft, 3, 4... Bearing, 5... Motor stator, 6... Casing, 6a
... lower casing, 7 ... lid, 8 ... electric wire, 1
0... Pump, 11... Projection plate, 12... Bearing supporter, 13... Lid, 14... Backing, 15...
Annular plate, 16... Water storage chamber, 17... Gap, 18.
...Water leak detector, 19.20...Mechanical seal,
21... Backing, 22... Auxiliary pump, 23.
...Passway, 22a...Thread part, 22b...Wall surface.

Claims (1)

[Scope of utility model registration request] A motor shaft 2 extending downwardly of the dry type motor is connected to a pump 10, and the motor shaft 2 between the pump 10 and the dry type motor is sealed by sealing devices 19 and 20. In a dry submersible motor pump having a liquid reservoir chamber 16a on the outer periphery, the water reservoir chamber 16 is partitioned between the liquid reservoir chamber 16a and the dry motor, and the sealing device 19 and the bearing 4 at the lower part of the motor shaft are separated. A passage 23 is formed between the motor shaft outer circumference and the water reservoir chamber 16 so that the liquid level in the water reservoir chamber 16 is higher than the lower surface of the bearing 4 at the lower part of the motor shaft. A dry type submersible motor pump characterized in that a liquid level detection device 18 is provided to detect the liquid level when the liquid level reaches the upper part.