JPH0676680U - Dry submersible motor pump - Google Patents

Abstract

(57) [Abstract] [Purpose] In a dry submersible motor pump, the air in the space inside the housing in which the electric motor is installed causes convection to perform ventilation, and the air functions as a heat medium or cooling medium. To have. [Constitution] The housing 4 in which the electric motor 6 is installed is connected to the pumping channel 2
And the upper and lower spaces 5a, 5 are installed in the rotor 9 of the electric motor 6.
The air passage 25 communicating with b is provided, and the housing 4
Is provided with a return passage 24 that communicates the spaces 5a and 5b, and the rotating shaft 7 is provided with a fan 26. [Effect] By the fan 26 that rotates together with the rotating shaft 7, the air is sent through the space 5b, the air passage 25, the space 5a, and the return passage 24.
When forced convection is carried out through, the heat generation in the electric motor 6 is suppressed by the ventilation effect at that time.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a dry submersible motor pump that employs an electric motor as a rotary drive source for an impeller.

[0002]

[Prior art]

 Submersible motor pumps that use an electric motor as the rotary drive source of the impeller can be roughly classified into three types: water-sealed type, oil-sealed type, and dry type. Among these submersible motor pumps, the water-sealed type has water around the motor coil and rotor of the electric motor, and the oil-sealed type has oil around the motor coil and rotor, whereas the dry type has The motor coil and rotor are surrounded by an air layer or space, which is essentially the same structure as a land motor. For this reason, the heat generated by the rotor of the electric motor, which is the heat source, causes water and oil to contact the rotor portion and radiate heat to the outside with good heat transfer in the water-sealed type and the oil-sealed type. Since the air space around the rotor and the rotor is an air layer, it can be said that the structure is such that heat is easily stored inside the motor due to the heat insulation effect of the air layer. Not only does the temperature tend to rise too much, but because the rotating shaft of the motor also has a large shaft diameter, the tendency for the temperature to rise too much due to the increased heat storage inside the rotating shaft is further promoted. To be done.

[0003]

[Problems to be solved by the device]

 As described above, conventionally, there is a problem that the rotor temperature and the rotating shaft temperature of the electric motor may be excessively increased with respect to the dry submersible motor pump, and such a tendency tends to occur especially in the dry submersible motor pump using the high-output electric motor. It was remarkable.

Therefore, the inventor of the present application has conducted an earnest research study with the intention of effectively dissipating the heat generated in the rotor of the electric motor to the outside and suppressing the rise of the rotor temperature in the dry submersible motor pump. As a result, the present invention has been completed.

That is, according to the present invention, a rotor of an electric motor is provided with a ventilation passage, and air in an internal space of a housing in which the electric motor is installed is forcibly fed into the ventilation passage, 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 the heat generation in the rotor and the heat storage in the rotating shaft by providing the above function.

[0006]

[Means for Solving the Problems]

 In the dry submersible motor pump according to the present invention, an electric motor is installed in a space surrounded by a housing arranged in a pumping channel, and an impeller is connected to a rotary shaft of the electric motor, and is sucked by the rotation of the impeller. In a dry submersible motor pump in which water is discharged through the pumping passage, the rotor of the electric motor is provided with a ventilation passage that communicates with the inner space of the housing that is provided on each side of the electric motor. A return passage is formed in the housing to connect the internal spaces on both sides of the electric motor, and a fan for forcibly circulating air inside the housing through the ventilation passage and the return passage on the rotary shaft. Is provided.

[0007]

[Action]

 In this configuration, when the electric motor is operated, the water sucked by the rotation of the impeller moves up the pumping channel. 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 to the ventilation passage of the rotor, and the ventilation action is performed in the ventilation passage. This ventilation action suppresses heat generation in the rotor of the electric motor, and as a result, it becomes difficult to store heat in the rotating shaft. Further, the air convection in the above-mentioned ventilation passage due to the ventilation effect is cooled by the water flowing in the pumping passage when it passes through the return passage of the housing after exiting into the internal space of the housing.

[0008]

【Example】

 FIG. 1 is a sectional view showing an essential part of a dry submersible motor pump according to an embodiment of the present invention. In the figure, 1 is a column, and the internal space of this column 1 serves as 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 vertical and substantially cylindrical shape, and an electric motor installed in a part of a space 5 surrounded by the housing 4. 6 and an impeller 8 connected to the rotating shaft 7 of the electric motor 6 and the like. 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 arranged around the rotor 9, which are cylindrical frames 11 Surrounded by.

The housing 4 includes a frame 11, a cylindrical lid fitting 13 connected to an upper end portion of the frame 11 via an upper partition wall 12, and an upper lid 14 closing an upper end opening of the lid fitting 13. And a pump casing 16 connected to the lower end of the frame 11 via a lower partition wall 15. A suction casing 18 is connected to the pump casing 16 and a guide vane 17 is provided on the pump casing 16. The impeller 8 is provided on a boss 19 and a cap 20 is mounted on the boss 19. The rotary shaft 7 is rotatably supported by a bearing 21 provided on the upper partition wall 12 and a bearing 22 provided on the lower partition wall 15. The rotary shaft 7 is also supported by a mechanical seal 23 provided on the pump casing 16. Numerals 5a, 5b and 5c are spaces secured inside the frame 11 and inside the lid 13 above and below the electric motor 6, and 14a is a cable insertion opening.

As for the pump body 3, its housing 4 is arranged in the pumping passage 2 inside the column 1, and in this state, the pump casing 16 and the suction casing 18 are projected from the lower end portion of the column 1.

Next, as shown in the drawing, ventilation paths 25 are formed so as to penetrate through the rotor 9 of the electric motor 6 in the circumferential direction, and the electric motor 6 is sandwiched by these ventilation paths 25. The spaces 5a and 5b on both sides are communicated with each other. On the other hand, the frame 11 forming the housing 4 is formed with a return passage 24 that connects the spaces 5a and 5b on both sides of the electric motor 6 to each other. Furthermore, in the space 5a above the electric motor 6, a fan 26 is attached to the rotary shaft 7, and a guide cylinder 27 provided on the upper surface of the rotor 9 is exposed to the suction port 26a of the fan 26. There is. The fan 26 is used to forcibly circulate air inside the housing 4, specifically, the frame 11 through the ventilation passages 25 ... And the return passage 24, as shown in FIG. A cross-flow fan can be preferably used, and this cross-flow fan has a function of laterally discharging air sucked from below. In FIG. 2, 26a is a blade.

In the dry submersible motor pump described above, when the electric motor 6 is driven, the rotary shaft 7 rotates together with the rotor 9, and the impeller 8 rotates together with the rotary shaft 7. Therefore, the water sucked from the suction casing 18 is rectified by the guide vanes 17 of the pump casing 16, then flows upward in the pumping passage 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 5b inside the frame 11 secured below the electric motor 6 passes through the ventilation passages 25 of the rotor 9. It enters the space 5a inside the fan 11 secured above the electric motor 6, is discharged to the side of the fan 26, and then is forcibly circulated through the return passage 24 to the space 5b below the electric motor 6. . For this reason, heat generation in the rotor 9 is suppressed by the ventilation effect when air convections the ventilation passages 25 of the rotor 9, so that heat accumulation in the rotating shaft 7 is suppressed and the temperature does not rise too much. To be prevented. Further, when passing through the return passage 24, it is cooled by the water flowing through the pumping passage 2. In addition, in FIG. 1, the flow of water flowing through the pumping channel 2 is shown by a white arrow b.

The amount of heat removed from the rotor 9 due to the ventilation effect varies depending on the amount of air convection in the ventilation passages 25 (ventilation amount), and the ventilation amount depends on the diameter of the holes forming the ventilation passages 25. change. From this, it is possible to set the amount of ventilation that enables effective cooling without lowering the pump performance by appropriately determining the diameter (hole diameter) and the number of the holes forming the ventilation passages 25. is there.

[0016]

[Effect of device]

 According to the present invention, even in a dry submersible motor pump having an air layer around the motor coil or rotor, the heat generated by the rotor of the motor is controlled by the ventilation effect of the air that is forcedly convected in the air passage of the rotor. Since it is carried away, heat generation of the rotor is suppressed, and as a result, heat storage on the rotating shaft is suppressed. Moreover, the air exiting the ventilation passage is cooled by the water flowing through the pumping passage while passing through the return passage, and then is forced back into the ventilation passage, increasing the rotor temperature of the electric motor. Not only prevents the excessive rotation of the rotary shaft, but also prevents a large amount of heat from being accumulated on the rotary shaft, which helps to improve safety during pump operation, but it also has a large-output electric motor using a rotary shaft with a large shaft diameter. This has the effect of enabling the production of a dry submersible motor pump.

[Brief description of 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 channel 4 Housing 5, 5a, 5b Space 6 Electric motor 7 Rotating shaft 8 Impeller 9 Rotor 24 Return passage 25 Ventilation passage 26 Fan

Claims (1)

[Scope of utility model registration request] 1. An electric motor is installed in a space surrounded by a housing arranged in a pumping channel, and an impeller is connected to a rotary shaft of the electric motor, and water sucked by the rotation of the impeller is the pumped water. In a dry submersible motor pump that discharges through a passage, the rotor of the electric motor is provided with a ventilation passage that communicates with the internal space of the housing that is provided on each side of the electric motor, and the electric motor is attached to the housing. A return passage that connects the inner spaces on both sides of the sandwich is formed,
A dry submersible motor pump, wherein a fan for forcibly circulating air inside the housing through the ventilation passage and the return passage is provided on the rotary shaft.