JP2000227088A - Vertical submerged motor-driven pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vertical submerged motor-driven pump in which there is no possibility to generate leakage of a pumping liquid from a scroll chamber to an oil casing, and poor lubrication is not generated on a mechanical seal. SOLUTION: A hollow oil chamber 27 is internally provided in an oil casing, and the hollow interior of the oil chamber 27 is communicated to a scroll chamber 2. Accompanying increase of volume of oil enclosed in the oil casing due to thermal expansion, the oil chamber 27 is contracted to spread the effective volume of the oil casing, meanwhile, accompanying decrease of oil volume due to temperature drop, the oil chamber 27 is expanded to reduce the effective volume of the oil casing, and hence oil in the oil casing is always held in the full condition. Pressure in the scroll chamber 2 is absorbed by the hollow oil chamber 27 to reduce pressure difference against the pressure in the oil casing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical submersible electric pump.

[0002]

[Prior art and its problems] Vertical type submersible electric pumps
As shown in FIG. 9, an oil chamber 122 is interposed between the spiral chamber 102 and the motor 113. However, during pump driving, the pressure in the spiral chamber 102 becomes high and the pressure difference between the oil chamber 122 and the oil chamber 122 increases. May enter the oil chamber 122 along the sliding surface of the mechanical seal 121. In addition, when the oil is supplied into the oil chamber 122, the oil volume is usually limited to about 80% in anticipation of a volume increase due to thermal expansion. Therefore, an air reservoir A is formed above the oil chamber 122, and the mechanical seal Above 121, poor lubrication occurs.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a vertical submersible electric pump which does not cause liquid leakage from a spiral chamber to an oil chamber and does not cause poor lubrication of a mechanical seal. It is in.

[0004]

In the vertical underwater electric pump according to the present invention, a hollow oil chamber is provided inside an oil chamber for lubricating a mechanical seal, and a spiral inside the hollow chamber of the oil chamber and a pump casing. Communication with the room.

[0005]

[Function] With the oil filled in the oil chamber in a state of being expanded while the oil chamber is expanded, the volume of the oil chamber expands due to thermal expansion, the oil chamber gradually contracts, and the effective volume of the oil chamber is expanded. As the oil volume decreases due to a decrease in temperature, the oil chamber gradually expands, the effective volume of the oil chamber is reduced, and the oil in the oil chamber is always kept at a level above the mechanical seal. Further, a pressure difference between the spiral chamber and the oil chamber generated during driving of the pump is reduced by the oil chamber.

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.

[0007] Reference numeral 1 denotes a pump casing made of a wear-resistant material such as rubber, and the inside thereof is formed in a spiral chamber 2. Reference numeral 3 denotes an impeller fitted in the lower guide portion of the motor shaft 4 and accommodated in the pump casing 1, and 5 denotes the pump casing 1
A suction cover fixed to the lower edge of the pump casing and having a pump suction port 6 opened in the center, 7 is a strainer, 8 is a seal plate fixed to the back of the pump casing 1, and 9 is a seal made of a wear-resistant material. The protective sheet 10 attached to the lower surface of the plate 8 is a reinforcing wall for preventing the pump casing 1 from being deformed outward by water pressure.
It is guided from the peripheral portion of the seal plate 8 and contacts the outer periphery of the winding of the pump casing 1. Reference numeral 11 denotes a cylindrical motor frame which stands upright on the seal plate 8 of the pump casing 1, and its upper end face is closed by mounting a head cover 12 or the like, and a motor 13 is accommodated therein. On the outer peripheral surface of the motor frame 11, a second oil chamber 15 and an electrical equipment chamber 16 are vertically arranged in a circumferential direction in parallel with a water channel 14 extending in the cylinder axis direction. 17.
... Reference numeral 17 denotes a partition for partitioning each of the chambers. The end portion 2E of the spiral in the spiral chamber 2 communicates with the lower end of the water passage 14, and the upper end of the water passage 14 communicates with the pump discharge port 19 via a guide passage 18 formed in the inner peripheral portion of the head cover 12. As shown in the drawings of the embodiment, two water passages 14 and 14 are disposed to face each other, and the lower ends of the two water passages 14 and 14 are double swirl chambers 2.
In this case, the upper ends of the water passages 14 and 14 are joined by the guide path 18 in the head cover 12 and communicate with the pump discharge port 19 when the end portions 2E and 2E of the winding are electrically connected to each other. The second oil chamber 15 is vertically provided so as to be narrowed between the water passages 14, 14 via a partition 17, and the lower end thereof is provided through an oil passage hole 20 formed in a lower portion of the motor frame 11. The upper end communicates with a first oil chamber 22 formed in the periphery of the mechanical seal 21, and the upper end communicates with an oil supply port 23 opened from the upper surface of the head cover 12.
Reference numeral 24 denotes an oil supply plug provided to the oil supply port 23. The electrical component room 16 communicates with the motor frame 11 through a lead wire outlet hole 25 provided on the inner surface thereof, and the upper end surface communicates with a power cable insertion port 26 above the motor frame 11.
Reference numeral 27 denotes an oil chamber made of a stretchable elastic material such as synthetic rubber in a hollow shape. In the drawings of the embodiment, the second oil chamber 15
The case where the first oil chamber 2 is installed in the inside is shown.
The effect is the same even if it is installed in the inside.

Prior to use of the pump, oil is supplied from the oil supply port 23 to fill the oil in the first oil chamber 22 and the second oil chamber 15 with oil. During the operation of the pump, the water sucked from the pump suction port 6 into the volute 2 causes the end portion 2E of the winding.
The water is discharged from the pump discharge port 19 through the guide path 18 while cooling the motor 13 in the motor frame 11 in the process of ascending the inside of the water path 14. As the operating time of the pump elapses, the oil in the first oil chamber 22 and the oil in the second oil chamber 15 gradually increase in volume due to the lubrication of the mechanical seal 21 and the absorption of heat generated by the motor 13, and the oil chamber 27 gradually contracts, and the effective volumes of the first oil chamber 22 and the second oil chamber 15 are expanded. If the pump stops and the time elapses, the oil volume decreases due to the temperature drop, but the oil chamber 27 gradually expands with the decrease in the oil volume, and the first oil chamber 22 and the second oil chamber 1
Since the effective volume of No. 5 is narrowed, the state where the oil reaches the upper part of the mechanical seal 21 is maintained. Therefore, even if the operation of the pump is started again, the mechanical seal 21
The lubrication function is not impaired. During the operation of the pump, a part of the pumped water is moved from the swirl chamber 2 to the oil chamber 27.
And the oil chambers 15, 2
The pressure difference in 2 is reduced and pumping intrusion into the oil chamber is prevented.

[0009]

According to the present invention, the pressure in the spiral chamber and the pressure in the oil chamber are balanced to eliminate liquid leakage,
In addition, the lubricating effect of the mechanical seal can be enhanced by always keeping the oil in the oil chamber full.

[Brief description of the drawings]

FIG. 1 is a vertical sectional side view of a portion of a vertical submersible electric pump according to the present invention in which a water channel and a second oil chamber are displayed.

FIG. 2 is a vertical sectional side view of a portion of the vertical submersible electric pump according to the present invention in which a water channel and an electrical equipment room are displayed.

FIG. 3 is a plan view of a motor frame of the vertical submersible electric pump according to the present invention.

FIG. 4 is a bottom view of a motor frame in the vertical submersible electric pump according to the present invention.

FIG. 5 is a vertical sectional side view taken along line AA of FIG. 3;

FIG. 6 is a longitudinal sectional side view taken along line BB of FIG. 3;

FIG. 7 is a bottom view of a head cover for closing an upper end surface of the motor frame shown in FIGS. 3 to 6;

FIG. 8 is a cross-sectional plan view taken along line CC of FIG.

FIG. 9 is a vertical sectional side view of a conventional vertical submersible electric pump, showing a case where oil in an oil chamber does not reach an upper portion of a mechanical seal.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pump casing 2 Volute chamber 15 2nd oil chamber 21 Mechanical seal 22 1st oil chamber 27 Oil chamber

Claims (1)

[Claims] A hollow oil chamber is provided in an oil chamber for lubricating a mechanical seal, and a hollow interior of the oil chamber is communicated with a spiral chamber in a pump casing. Type submersible electric pump.