JPH0119574Y2 - - Google Patents

Description

[Detailed description of the invention] [Purpose of the invention] "Field of industrial application" The present invention relates to a motor cooling structure for a submersible motor pump.

``Problems to be solved by conventional technology and ideas'' Conventionally, submersible motor pumps have a pump at the bottom and a motor at the top, and part of the pumped water is used to cool the motor. In the previous method, the structure of the pump was complicated and the cooling efficiency was reduced. In the case of the one described below, the air in the cooling chamber cannot be smoothly discharged, resulting in a significant decrease in cooling capacity due to air stagnation.

This idea eliminates the above-mentioned drawbacks of submersible motor pumps that cool the motor by introducing a portion of pumped water into the motor cooling chamber, and improves motor cooling efficiency by creating a cooling structure that does not leave any air in the motor cooling chamber. The purpose of this invention is to provide a cleaning port for easy cleaning of the motor cooling chamber.

"Means for Solving the Problems" The present invention is a vertical submersible motor pump having a pump, a motor, a pump cover, a cooling water introduction passage, a cooling water drain pipe, and an automatic air vent valve. is integrally connected to the upper part of the pump, and the motor is covered with a pump cover at intervals around the outer circumference, and a motor cooling chamber is formed between the two, and the motor cooling chamber is connected to one end of the cooling water introduction path. is connected to the bottom, one end of the cooling water drain pipe is connected to the top, and a part of the pumped water is introduced as cooling water.
The other end of the cooling water drain pipe is opened on the side of the pump, and the automatic air vent valve is installed at the top of the cooling water drain pipe or the top of the pump cover. This is a vertical submersible motor pump.

"Example" Hereinafter, an example of this invention will be described according to the drawings. FIG. 1 is a longitudinal sectional view of the submersible motor pump of this invention. However, the figure is shown rotated 90 degrees, and the right side of the figure is the top. The figure shows a submersible motor pump with a pump at the bottom and a motor at the top.

The lower bracket 1 and the intermediate casing 2 are fitted together via a sealing ring 3, and bolts 4 are passed through bolt holes in the lower bracket 1 and screwed into the female threads of the intermediate casing 2 to be fastened.

A shaft sealing device 5 is installed between the lower bracket 1 and the intermediate casing 2. Lower bracket 1
Lubricating and cooling oil for the shaft sealing device 5 can be taken in and out of the space 5a between the lower bracket 1 and the intermediate casing 2 by means of a plug 6 provided therein.

A liner ring 7 is fitted into the lower part of the intermediate casing 2. Fit into the end of the main shaft 8 via the key 9,
An impeller 13 is fixed by a stirring blade 12 which also serves as a blade fixing nut screwed into the male thread at the end of the main shaft 8 through a washer 11, and the main plate 1 of the impeller 13 is
The liner part 13a of the annular projection on the back side of 3c fits into the liner ring 7 with a small gap, and the inner circumference of the liner ring 7 approaches the boss of the impeller 13 with a very small gap so as to form a dust seal. Impeller 1
A balance hole 13b is bored in the main plate 13c of No. 3.

The pump casing 14, which has a fitting part 14a with the intermediate casing 2 through which the impeller 13 can pass, is fixed to the intermediate casing 2 by bolts 15 inserted through bolt holes in the intermediate casing 2 and screwed in. has been done. A suction cover 18 having a fitting portion with a larger diameter than the impeller 13 is fitted into the pump casing 14 via a sealing ring 16 and a shim 17 that adjusts the gap between the side ends of the blades of the impeller 13 and the suction cover 18. A stay bolt 23 inserted through a cylindrical bolt cover 22 provided on the outer circumferential side of a strainer 21 integrally formed on the pump stand 19 is inserted into the suction cover 18 and the hole of the shim 17 to be implanted in the pump casing 14. The strainer 21 is installed by screwing the nut 24 onto the stay bolt 23 and pressing the pump stand 19 with the nut 24.
The suction cover 18 and the like are fastened together and fixed to the pump casing 14.

The main shaft 8 has a lower ball bearing 25 fitted into the lower bracket 1, a sealing ring 26 inserted between the lower bracket 1 and the motor frame 27 fitted with the sealing ring 2.
It is supported by an upper ball bearing 31 that is fitted into a bearing plate 29 that is inserted into the upper ball bearing 31. Lower ball bearing 25
The presser plate 25a is fixed to the lower bracket 1 by a set screw 25b so as to be pressed by the presser plate 25a, and a wave washer 31a is elastically inserted between the upper ball bearing 31 and the bearing plate 29. A rotor 32 is fixed to the main shaft 8, and a stator 33 is fixed to the motor frame 27. Although not shown in FIG. 1, as shown in FIG. 2, the motor frame 27 and the lower bracket 1 are inserted into the bolt holes of the flange of the lower bracket 1 at multiple locations on the circumference, and the bolts 3 are inserted through the bolt holes of the flange of the lower bracket 1.
4 is screwed into the female thread of the motor frame 27 and fixed.

An upper bracket 36 is fitted into the bearing plate 29 with a sealing ring 35 in between.
6. Insert the bolt 37 through the bolt hole of the bearing plate 29.
is screwed into and fastened to the motor frame 27.

A cylindrical pump cover 38 that is placed over the motor frame 27 to form a cooling water cylinder between the motor frame 27 and the motor frame 27 has an elastic boot 39 fitted into its lower end.
The inner flange 3 is fitted into the spigot on the outer periphery of the flange 27b, and the upper end is welded to the outer cylinder part.
8a fits into the substantially cylindrical connector seat 36a provided on the upper bracket 36, and the upper bracket 3
6 through a gasket 41, and furthermore, an annular hand grip portion 42a and a central mounting flange 42.
The mounting flange 42b of the handle 42, which is rigidly connected between b and 42c by a radial arm 42c, is brought into contact with the inner flange 38a of the pump cover 38, and the mounting flange 42b, the inner flange 38a, and the bolt hole of the packing 41 are inserted. A bolt 43 is screwed into the upper bracket 36.

The upper bracket 36 has an underwater cable 4 at the top.
A bolt 46 is screwed into the connector seat 36a through a bolt hole of a connector 45 which is watertightly fitted into the connector seat 36a leading the motor 4 into the motor.

An auto cut 47 is fixed to the bearing plate 29 within the upper bracket 36. The bearing plate 29 is provided with holes for wiring between the stator 33 and the terminal 45a of the connector 45 and between the auto cut 47 and the stator 33.

One side opens toward the impeller back chamber 50 at the back of the impeller 13 on the outer peripheral side of the liner part 13a that creates a throttle effect with the liner ring 7 of the impeller 13, and the other side opens toward the impeller back chamber 50, and the other side opens toward the impeller back chamber 50.
A cooling water introduction passage 49 that opens into the motor cooling chamber 48 between the two parts is provided passing through the intermediate casing 2, the lower bracket 1, and the motor frame 27.

A pipe joint 5 is attached to the inner flange 38a of the pump cover.
1 is fixed, and a cooling water discharge pipe 52 is attached so as to communicate with the motor cooling chamber 48 via a pipe joint 51, and the cooling water discharge pipe 52 hangs downward along the submersible motor pump. It opens to the outside near the pump casing 14. An automatic air vent valve 53 is attached to the highest position of the cooling water discharge pipe 52. The automatic air vent valve 53 has a function of discharging only air when there is air in the cooling water discharge pipe 52, but not discharging liquid. It is preferable that the cooling water discharge pipe 52 is taken out from the highest position of the motor cooling chamber 48, and the piping method is not limited to that in the embodiment. Even when the water level of the water reservoir is low, the opening at the lower end of the cooling water discharge pipe 52 is exposed and the drainage from the cooling water discharge pipe 52 does not splash out, and when the water reservoir is at a low level, the opening to the outside is opened to create a siphon effect. The part should also come down as far as possible. Incidentally, if the cooling water drain pipe 52 is partially made of a transparent pipe, for example, a transparent synthetic resin, the operating state can be checked. In this case, for example, when a soft transparent vinyl pipe is used, the automatic air vent valve 53 is attached directly to the inner flange 38a of the pump cover.

FIG. 3 is an enlarged longitudinal sectional view of the automatic air vent valve.
The automatic air vent valve 53 consists of a valve body 54 screwed into the cooling water discharge pipe 52, a ball valve 55 housed in the valve body 54, and a filter 56 stretched on the inlet side of the valve body 54. A conical valve seat portion 54 is located at a position facing the filter 56 on the inlet side of the valve 54.
A ball valve 55 that opens and closes the valve seat portion 45c is disposed between the filter 56 and the valve seat portion 45c so as to be movable up and down.

If there is air in the cooling water discharge pipe 52, the air passes through the filter 56, passes through the gap between the ball valve 55 and the inlet of the valve body 54, and enters the relief hole 5 from the valve port 54a.
It is discharged to the outside through 4b. If there is no air in the cooling water discharge pipe 52, the liquid trying to exit through the filter 56 lifts the ball valve 55, and the ball valve 55 becomes a conical valve in front of the valve port 54a of the valve body 54 when viewed from the inlet side. The liquid comes into contact with the seat portion 54c so that no liquid comes out.

For this reason, a material made of, for example, synthetic resin and having an appropriate specific gravity for the ball valve 55 and a gap between the inlet of the ball valve 55 and the valve body 54 are selected so that the ball valve 55 operates due to the action of air and liquid as described above. do. The automatic air vent valve 53 is installed so that the inlet with the filter 56 communicates with the motor cooling chamber 48 and the outlet side relief hole 53b faces the outside.

The lower flange of the motor frame 27 is provided with an automatic leakage prevention valve 57 that selectively communicates the motor cooling chamber 48 with the outside. The automatic leak check valve 57 automatically closes when the pressure inside the motor cooling chamber 48 becomes higher than the external pressure.

In order to maintain the cooling capacity of the conventional motor cooling chamber 48, the cleaning port used when cleaning the interior by spraying high-pressure water, for example, is a screw-in plug, so it is necessary to remove and install the plug when cleaning. When the submersible motor pump is submerged in water, liquid only enters from the opening of the motor cooling water passage, so the cooling water does not fill up in the motor cooling chamber 48, and if the submersible motor pump is operated immediately, the cooling capacity will decrease. In some cases, there was a shortage. Therefore, in this embodiment, an automatic leakage check valve is provided as described below to facilitate cleaning of the motor cooling chamber 48, and as soon as the submersible motor pump is submerged in water, the motor cooling chamber 48 is immediately filled with cooling water and cooled. can be done immediately.

FIG. 4 is a longitudinal sectional view of the automatic leak check valve. The automatic leak prevention valve 57 has a valve body 58 screwed into the cleaning port 27a at the bottom of the motor frame and a valve body 58.
It consists of a ball valve 59 housed in the valve body 58 and a cap 61 screwed into the valve body 58. The cap 61 is smaller than the ball valve 59 so that it hangs down from the cleaning port 27a at the bottom of the motor cooling chamber 48 and does not allow the ball valve 59 to pass through. Below the liquid passage 62 having a circular diameter cross section, the valve body 58 is provided with a valve seat portion 58a that is closed by a ball valve 59.
8b and can be accommodated in a cylindrical protrusion 58c provided on the valve body 58, which is closed by a side cap 61.

When the external pressure is higher than the pressure in the motor cooling chamber 48, the ball valve 59 is guided by the bent hole guide 58b and rises, and the external liquid passes through the liquid passage 62 from between the valve seat portion 58a and the ball valve 59 to the motor cooling chamber 48. to go into. When the pressure inside the motor cooling chamber 48 becomes higher than the external pressure, the ball valve 59 moves down along the bent hole guide 58b, and is closed by applying internal pressure and coming into contact with the valve seat portion 58a. When cleaning the inside of the motor cooling chamber 48, the ball valve 59 escapes when high-pressure water is sent in from the outside.
The liquid passage 62 serves as a cleaning hole, and clean water is sent into the motor cooling chamber 48, thereby cleaning the motor cooling chamber 48.

When energized from the underwater cable 44, the stator 3
3 is energized and rotates the rotor 32, the main shaft 8 rotates, and the impeller 13 rotates. The liquid passes through the strainer 21 from the water reservoir, is sucked in through the suction port 14b, is accelerated and pressurized by the impeller 13, and the pressure is recovered in the swirl chamber 14c, and is then transferred from the discharge port 14d to, for example, a connected bent pipe 63 or straight pipe 64. The liquid is sent upward.

When the submersible motor pump is lifted out of the water, the cooling water in the motor cooling chamber 48 passes through the cooling water introduction path 49, enters the impeller back chamber 50, and then flows through the gap between the outer peripheral end surface of the impeller main plate 13c and the intermediate casing 2. It enters the pump casing 14 through the suction port 14b and the strainer 21, and is discharged through the automatic air vent valve 53 into the motor cooling chamber 48.
There is air inside. When the submersible motor pump is placed in a water reservoir, the automatic leakage prevention valve 57 is opened by external water pressure, and the liquid in the water reservoir enters the motor cooling chamber 48.
The air in the motor cooling chamber 48 is then pushed upward. The liquid that enters the impeller back chamber 50 from the strainer 21, suction port 14b, and pump chamber through the gap between the impeller main plate 13c and the intermediate casing 2 passes through the cooling water introduction path 49 and enters the motor cooling chamber 48. The water in the water reservoir is pushed up from the lower end of the cooling water discharge pipe 52. The automatic air vent valve 53 then remains open and air escapes upward. When the automatic air vent valve 53 is lowered below the water level of the water reservoir, air still escapes because the pressure inside the motor cooling chamber 48 is large due to the difference in water head above and below the automatic air vent valve 53.

When the pump is operated, the liquid flows from the volute chamber 14c through the gap between the main plate 13c of the impeller 13 and the intermediate casing 2, is depressurized and flows into the impeller back chamber 50, passes through the cooling water introduction path 49, and enters the motor cooling chamber 48. The coolant is fed into the motor cooling chamber 48 and rises at a slow speed until it reaches the cooling water discharge pipe 5 from the upper part of the motor cooling chamber 48.
2 and returns to the water reservoir from the lower end of the cooling water discharge pipe 52. Air in the flow of cooling water is discharged from the automatic air vent valve 53. Since the automatic leak prevention valve 57 closes when the pressure of the liquid in the motor cooling chamber 48 increases when there is no air in the motor cooling chamber 48, the pressure in the motor cooling chamber 48 is maintained and a large amount of water is pumped to the impeller back chamber 50. More liquid that should be discharged does not flow. During pump operation, even if the water level falls below the automatic leak check valve 57 and the automatic leak check valve 57 is exposed, even if the cooling water in the motor cooling chamber 48 is under no pressure, the water in the motor cooling chamber 48 will still flow. Not possible. As the water level further decreases and the stirring blades 12 stir the sand, mud, slurry, etc. on the bottom of the water reservoir, they also begin to suck in air, resulting in pumped liquid in an air-water state, and the motor cooling chamber 48 also pumps air-water. Although some of the liquid is sent to the motor cooling chamber 48, the amount of cooling water sent to the motor cooling chamber 48 is small as in the case where the water level is high, so the flow of cooling water upward in the motor cooling chamber 48 is gradual. . Therefore, in the motor cooling chamber 48, only air bubbles rapidly rise to the top and flow into the cooling water discharge pipe 52, so that the motor cooling ability is maintained. Air is then sequentially released from the automatic air vent valve 53.

[Effect of idea]

As described above, this invention is a vertical submersible motor pump that has a pump, a motor, a pump cover, a cooling water inlet passage, a cooling water drain pipe, and an automatic air vent valve, and the motor is mounted on the top of the pump. The motor is integrally connected, and the motor is covered with a pump cover at intervals around the outer circumference, and a motor cooling chamber is formed between the two. One end of the water drain pipe is connected to the upper part, and a part of the water pumped by the pump is introduced and discharged as cooling water, and the other end of the cooling water drain pipe is opened on the side of the pump.
The automatic air bleed valve is installed on the top of the cooling water drain pipe or the top of the pump cover.Since it is a vertical submersible motor pump, it is possible to bleed air to the top of the cooling chamber, resulting in a good cooling effect. It is. The cooling effect is good because the cooling water flows around the entire outer periphery of the motor frame including the motor frame bearing plate and the upper bracket.

If an automatic leakage valve is attached to the lower part of the motor cooling chamber that has the function of a motor cooling chamber cleaning hole that automatically closes when the pressure inside the cooling chamber is higher than the outside pressure, cleaning the inside of the cooling chamber will be easier. I can do it. When the submersible motor pump is installed in a water reservoir, external liquid can enter the motor cooling chamber from the automatic leak prevention valve, and air in the motor cooling chamber can escape from the automatic air bleed valve, so the motor cooling water quickly fills and the motor cools. There is no need to worry about the cooling capacity even if you start it up immediately. That is, the phenomenon that air remains for a long time after the motor is operated does not occur when there is no automatic air vent valve. If the cooling water discharge pipe is transparent, it is possible to indirectly know the motor cooling water supply state and the operating state of the air valve when the water reservoir level drops.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of a submersible motor pump according to an embodiment of this invention, Fig. 2 is a longitudinal sectional view showing a partial fastening structure of Fig. 1, and Fig. 3 is a longitudinal sectional view of an automatic air vent valve.
FIG. 4 is a longitudinal sectional view of the automatic leak check valve. 38...Pump cover, 48...Motor cooling chamber, 49...Cooling water introduction path, 52...Cooling water discharge pipe, 53...Automatic air vent valve,...Pump,...
…motor.

Claims (1)

[Scope of utility model registration request] Pump, motor, and pump cover 38
, a cooling water introduction path 49 , a cooling water drain pipe 52 ,
A vertical submersible motor pump having an automatic air vent valve 53, the motor is integrally connected to the upper part of the pump, and the motor is covered with a pump cover 38 at intervals around the outer circumference, and the motor is connected between the two. A cooling chamber 48 is formed, and a motor cooling chamber 48
One end of the cooling water introduction passage 49 is connected to the lower part, and one end of the cooling water drain pipe 52 is connected to the upper part, and a part of the water pumped by the pump is introduced and discharged as cooling water. A vertical submersible motor pump characterized in that the other end is opened on the side of the pump, and the automatic air vent valve 53 is attached to the upper part of the cooling water drain pipe 52 or the upper part of the pump cover 38.