JPS5924880Y2 - Cooling structure of submersible pump motor - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a cooling structure for a motor for a submersible pump, which is capable of cooling the motor while it is being operated while being exposed to water.

In so-called lower-shaft external submersible pumps, in which the pump casing containing the impeller is installed below the motor,
Water can be pumped up if only the pump suction port is submerged in water, but if the motor is exposed above the water surface, the motor frame may not be sufficiently cooled and the motor may burn out.

In order to prevent this, a temperature switch or the like is provided, but in any case, the operation of the pump is interrupted even though it is in a state where water can be pumped, and continuous operation cannot be performed.

The present invention was developed in view of the above circumstances, and its purpose is to cool the motor so that it can be operated continuously while the pump is able to suck water even when the motor is exposed above the water surface. An object of the present invention is to provide a cooling structure for a submersible pump motor.

Hereinafter, the present invention will be explained with reference to the illustrated embodiments.

In FIG. 1, a pump casing 1 includes a main body 2 and a lid 3. As shown in FIG.

A frame 5 of a motor 4 disposed above a lid 3 is attached to the pump casing 1 .

A shaft 6 of the motor 4 passes through a shaft seal 7 provided on the lid 3 and projects into the pump casing 1, and an impeller 8 is attached to its tip.

A shaft sealing section 9 is formed behind the impeller 8, and an exhaust hole 10 is formed in the lid 3 for discharging air within the shaft sealing section 9 to the outside.

The above configuration may be the same as that of the conventional device, and as the internal pressure of the pump casing 1 increases when the impeller rotates, the air in the compartment 9 is discharged to the outside from the exhaust hole 10 along with water, so that no air bubbles remain. It is constructed so that only water is released.

A lower end portion of a tubular water guide member 12 is attached to the lid 3 at the outlet 11 of the exhaust hole 10 .

The upper end of the water guide member 12 extends upward with its upper end slightly inclined toward the center of the motor 4 so that the water spouted from the upper end is directed toward the outer periphery of the motor frame 5 .

A plurality of the water guide members 12 are arranged around the outer circumference of the motor frame 5 as necessary.

Instead of the tubular water guide member 12, a curved plate water guide member 13 may be provided as shown in FIG.

The water guide member 13 includes a concave portion 14 facing the outlet 11 of the exhaust hole 10 and is configured such that water ejected from the outlet 11 collides with the concave portion 14 and is directed toward the motor frame 5. .

According to the above configuration, even if the water level drops and the motor frame 5 is exposed above the water surface, the water remains in the compartment 9 while the pump is able to pump water in the driving state of the impeller 8.
Since the water is introduced from the water through the exhaust hole 10 to the water guiding member 12.13 and radiated to the outer circumference of the frame 5, the motor 4 is sufficiently cooled.

Therefore, the pump can be operated continuously without interruption.

That is, as shown in FIG. 3 illustrating the relationship between the elapsed time t and the winding temperature T of the motor 4 when the motor 4 is operated in air, in the conventional device shown by the broken line B, the winding temperature T
At time 1. reaches the operation stop temperature T. ．． 13...
It is stopped at..., and at time t2...
. . . When the temperature T2 at which operation is possible is reached, the winding is restarted and the operation and stop are repeated alternately.In contrast, in the present invention shown by the solid line A, the winding temperature T is kept below the operation stop temperature T1. It is possible to operate stably and continuously at all times.

As described above, the present invention is provided with a water guiding member located near the outlet of the exhaust hole that communicates with the shaft sealing section and guiding the water flowing out from the exhaust hole when the impeller is driven to the outer periphery of the motor frame. , the motor is sufficiently cooled even when operating in air.

Therefore, there is no need to provide a temperature switch or the like, and the pump can be efficiently operated continuously.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an embodiment of the present invention, FIG. 2 is a cross-sectional view showing a modification of the main part, and FIG. 3 is a diagram illustrating a variation in the temperature of the motor windings. DESCRIPTION OF SYMBOLS 1... Pump casing, 4... Motor, 5... Frame, 8... Impeller, 9... Shaft sealing section, 10... ...Exhaust hole 1
2.1'3...Water guiding member.

Claims (1)

[Scope of utility model registration request] Attached to the pump casing containing the impeller,
In a submersible pump in which a frame outer peripheral part of a motor for driving the impeller extends above the pump casing, the motor is located near the outlet of an exhaust hole communicating with a shaft sealing section arranged behind the impeller; A cooling structure for a motor for a submersible pump, characterized in that a water guiding member is provided to guide water flowing out from the exhaust hole to the outer circumference of the motor frame when the impeller is driven.