JP2581845Y2 - Dry type submersible motor pump - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dry submersible motor pump employing an electric motor as a rotary drive source for an impeller.

[0002]

2. Description of the Related Art Submersible motor pumps employing an electric motor as a rotary drive source for an impeller can be broadly classified into three types: a water seal type, an oil seal type, and a dry type. In these submersible motor pumps, the water-sealed type pump is filled with water around the motor coil and the rotor of the electric motor, and the oil-sealed type pump is filled with oil around the motor coil and the rotor. An air layer or space is formed around the coil and the rotor, and has essentially the same structure as a land motor.
For this reason, the heat generated by the rotor of the motor, which is a heat source, is such that water or oil is in contact with the rotor portion and is radiated to the outside with good heat transfer in a water seal type or an oil seal type. Since the air layer is around the rotor and the rotor, it can be said that the heat insulation function of the air layer makes it easy to store heat inside the motor.
In particular, in the case of a high-power motor, not only does the rotor temperature tend to rise too much, but also the rotating shaft of the motor has a large shaft diameter, so the amount of heat stored inside the rotating shaft increases accordingly. The tendency for the temperature to rise too high is further promoted.

[0003]

[Problems to be solved by the invention] As described above, conventionally,
The dry-type submersible motor pump has a problem that the rotor temperature and the rotating shaft temperature of the electric motor may be excessively increased. In particular, such a tendency is remarkable in a dry-type submersible motor pump using a high-output electric motor.

[0004] The inventor of the present application has conducted intensive research on a dry-type submersible motor pump with the intention of effectively radiating heat generated in the rotor of the motor to the outside to suppress a rise in the rotor temperature. As a result, the present invention was completed.

That is, according to the present invention, the rotor of the electric motor is provided with a ventilation path, and the air in the internal space of the housing in which the motor is installed is forcibly sent into the ventilation path, and the air is used as a heat medium or a cooling medium. It is an object of the present invention to provide a dry-type submersible motor pump capable of suppressing heat generation in the rotor and suppressing heat storage in the rotating shaft by having the function described above.

[0006]

According to the dry submersible motor pump of the present invention, an electric motor is installed in a space surrounded by a housing provided in a pumping passage, and an impeller is connected to a rotating shaft of the electric motor. In a dry-type submersible motor pump in which water sucked by the rotation of the impeller is discharged through the pumping passage, ventilation that connects the internal space of the housing provided on both sides of the electric motor to the rotor of the electric motor. A return passage is formed in the housing, and a return passage communicating with the internal space on both sides of the electric motor is formed in the housing. Air is supplied to the rotating shaft inside the housing through the ventilation passage and the return passage. A fan for forced circulation is provided.

[0007]

In this configuration, when the electric motor is operated, the water sucked by the rotation of the impeller rises in the pumping passage. On the other hand, since the fan rotates together with the rotating shaft of the electric motor, the air in the internal space of the housing is forcibly sent into the ventilation path of the rotor, and the ventilation action is performed in the ventilation path. Due to this ventilation action, heat generation at the rotor of the electric motor is suppressed, and as a result, heat storage at the rotating shaft becomes difficult. Further, the air that has convected through the ventilation path by the ventilation action exits the internal space of the housing, and is cooled by the water flowing through the pumping passage when passing through the return passage of the housing.

[0008]

1 is a sectional view showing a main part of a dry type submersible motor pump according to an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a column, and an internal space of the column 1 is a pumping channel 2.

Reference numeral 3 denotes a pump main body. In this embodiment, the pump main body 3 includes a housing 4 assembled in a substantially vertical cylindrical shape, and an electric motor 6 installed in a part of a space 5 surrounded by the housing 4. And an impeller 8 connected to the rotating shaft 7 of the electric motor 6. The electric motor 6 has the rotating shaft 7, a rotor 9 to which the rotating shaft 7 is fixed, and a coil 10 as a stator provided around the rotor 9, which are surrounded by a cylindrical frame 11. Have been.

The housing 4 includes a frame 11, a cylindrical lid 13 connected to an upper end of the frame 11 through an upper partition 12, an upper lid 14 closing an upper end opening of the lid 13. And a pump casing 16 connected to a lower end of the frame 11 via a lower partition wall 15. Then, the suction casing 1 is inserted into the pump casing 16.
8 and the pump casing 16
Is provided with a guide vane 17. The impeller 8 is provided on a boss 19, and the boss 19 is
0 is attached. The rotating shaft 7 is rotatably supported by a bearing 21 provided on the upper partition 12 and a bearing 22 provided on the lower partition 15. Also,
The rotating shaft 7 is also supported by a mechanical seal 23 provided on the pump casing 16. 5a, 5b,
5c is a space secured above and below the electric motor 6 inside the frame 11 and the lid 13 and 14a is a cable insertion port.

The housing 4 of the pump body 3 is provided in the water pumping passage 2 inside the column 1, and in this state, the pump casing 1 extends from the lower end of the column 1.
6 and the suction casing 18 are projected.

Next, as shown in the drawing, ventilation passages 25 are formed in the circumferential direction of the rotor 9 of the motor 6 at a plurality of locations in the circumferential direction, and the motor 6 is sandwiched by the ventilation passages 25. The spaces 5a and 5b on both sides communicate with each other. On the other hand, the frame 11 constituting the housing 4 is formed with a return passage 24 which communicates the spaces 5a, 5b on both sides of the electric motor 6. Further, in the space 5a above the electric motor 6, the fan 2
The guide tube 27 provided on the upper surface of the rotor 9 faces the suction port 26a of the fan 26. The fan 26 is for forcibly circulating air inside the housing 4, specifically, inside the frame 11, through the ventilation passages 25 and the return passage 24. The cross flow shown in FIG. A fan can be suitably used, and this cross flow fan has a function of discharging air sucked from below to the side. Note that FIG.
In the figure, 26a is a blade.

In the above-described dry type submersible motor pump, when the electric motor 6 is driven, the rotating shaft 7 rotates with the rotor 9 and the impeller 8 rotates with the rotating shaft 7. For this reason, after the water sucked from the suction casing 18 is rectified by the guide vanes 17 of the pump casing 16,
The water flows upward through the water pumping channel 2 and is discharged from a discharge port (not shown).

When the fan 26 rotates together with the rotating shaft 6 during such pump operation, the air in the space 5 b inside the frame 11 secured below the electric motor 6 passes through the ventilation passages 25 of the rotor 9. After entering the space 5a inside the fan 11 secured above the electric motor 6 and discharging to the side of the fan 26, it is forcibly circulated through the return passage 24 to the space 5b below the electric motor 6. . For this reason, the heat generated in the rotor 9 is suppressed by the ventilation effect when the air convections through the ventilation passages 25 of the rotor 9, whereby the heat storage in the rotating shaft 7 is suppressed and the temperature is prevented from rising too much. You. Further, when passing through the return passage 24, it is cooled by the water flowing through the pumping passage 2. In FIG. 1, the flow of water flowing through the water pumping channel 2 is indicated by a white arrow b.

The amount of heat removed from the rotor 9 by the ventilation varies depending on the amount of air (ventilation) flowing through the ventilation passages 25, and the amount of ventilation varies depending on the diameter of the holes forming the ventilation passages 25. Accordingly, by appropriately determining the diameter (hole diameter) and the number of the holes forming the ventilation paths 25, it is possible to set the amount of air that can be effectively cooled without lowering the pump performance. is there.

[0016]

According to the present invention, even in a dry type submersible motor pump in which an air layer is formed around the coil and the rotor of the motor, the heat generated by the rotor of the motor causes forced air to flow through the air passage of the rotor. Since the rotor is removed by the ventilation action, heat generation of the rotor is suppressed, and as a result, heat storage at the rotating shaft is suppressed. In addition, since the air that has exited the ventilation passage is cooled by the water flowing through the pumping passage while passing through the return passage, it is forcibly fed into the ventilation passage again, so that the rotor temperature of the motor becomes too high. Not only prevents a large amount of heat from being stored on the rotating shaft, which helps to improve the safety of the pump during operation,
There is an effect that it is possible to manufacture a dry-type submersible motor pump having a high-output motor using a rotating shaft having a large shaft diameter.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a main part of a dry-type submersible motor pump according to an embodiment of the present invention.

FIG. 2 is a plan view showing a specific example of a fan.

[Explanation of symbols]

 2 Pumping path 4 Housing 5, 5a, 5b Space 6 Motor 7 Rotary shaft 8 Impeller 9 Rotor 24 Return path 25 Ventilation path 26 Fan

──────────────────────────────────────────────────続 き Continuation of the front page (56) References Jikken Sho 43-14590 (JP, Y1) (58) Fields investigated (Int. Cl. ⁶ , DB name) F04D 13/08 F04D 7/02 F04D 29 / 58

Claims (1)

(57) [Scope of request for utility model registration] An electric motor is installed in a space surrounded by a housing provided in a pumping passage, an impeller is connected to a rotating shaft of the electric motor, and the water sucked by the rotation of the impeller is pumped by the pump. In a dry type submersible motor pump discharged through a passage, an air passage is provided in a rotor of the electric motor to communicate an internal space of the housing provided on both sides sandwiching the electric motor, and the electric motor is provided in the housing. A return passage communicating with the internal space on both sides sandwiching is formed,
A dry-type submersible motor pump, wherein a fan for forcibly circulating air inside the housing via the ventilation path and the return path is provided on the rotating shaft.