JPH0942185A - Submerged pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent foreign matter from choking an air vent hole provided in a pump casing SOLUTION: An impeller is arranged inside an impeller chamber 12 in the upper part of a pump casing 10, and the peripheral wall face 12a of the impeller chamber 12 is provided with an air vent hole 12b, which is provided in a low pressure domain in the downstream in the rotating direction of the impeller 11 to a discharge pipe line 14 communicating with the pump casing 10. In addition, a guide part 12c is provided adjacently to the air vent hole 12b in an upstream in the rotating direction of the impeller 11, and leads fluid made to flow by the impeller 11 to the inner peripheral side of the pump casing 10.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a submersible pump used for pumping sewage and the like in a sewage tank, a manhole pumping station, a reservoir, and the like.

[0002]

2. Description of the Related Art A submersible pump used for pumping up sewage or the like stored in a sewage tank usually has a cylindrical motor and an impeller connected to a rotary shaft of the motor. The vehicle is arranged in the pump casing. When the impeller arranged in the pump casing rotates, the sewage is sucked into the pump casing and discharged to the discharge pipe line portion extending tangentially to the pump casing. A discharge port is provided at the tip of the discharge conduit,
The sewage flowing from the pump casing into the discharge conduit is
It is discharged from the discharge port to the outside.

In such a submersible pump, an air vent hole is provided for discharging the air in the pump casing when the submersible pump is pulled up from the sewage tank for maintenance or the like and then installed in the sewage tank again. Not only in such a case, but also when sucking air together when draining the sewage in the sewage tank, the air can be released from this air vent hole to prevent air lock. There is. The air vent hole is provided in the upper surface of the discharge pipe portion of the pump casing or in the upper part of the peripheral wall surface located on the upstream side in the rotational direction of the impeller with respect to the portion communicating with the discharge pipe portion of the pump casing.

[0004]

The sewage sucked into the pump casing flows in the circumferential direction by the rotation of the impeller and flows into the discharge pipe section by the centrifugal force. Therefore,
The sewage flowing in the pump casing is in a high pressure state on the front side that flows into the discharge pipeline, and the sewage flows in the discharge pipeline in a high pressure state. For this reason, if the air vent hole is provided on the upper surface of the discharge conduit, the high pressure sewage may be discharged from the air vent hole. Similarly, high-pressure sewage flowing in the pump casing may be discharged from an air vent hole provided on the peripheral surface of the pump casing on the upstream side in the rotational direction of the impeller with respect to the discharge conduit.

Since foreign matter is mixed in the sewage sucked into the pump casing, if the high-pressure sewage is discharged through the air vent hole, the foreign matter may be discharged through the air vent hole. In that case, foreign matter may adhere to the air vent hole and block the air vent hole. When the air vent hole is blocked by a foreign substance, when the pump is pulled up from the sewage tank for maintenance or the like and is installed and started again, an air lock is caused to prevent the sewage from being pumped.

An object of the present invention is to solve such a problem, and an object of the present invention is to provide a submersible pump in which an air vent hole is not likely to be blocked by a foreign substance mixed in sewage or the like.

[0007]

The submersible pump of the present invention comprises:
An impeller attached to a rotating shaft of a motor is disposed in a pump casing, and the submersible pump discharges fluid sucked in the pump casing from a discharge port communicating with the pump casing by rotation of the impeller. The air vent hole is provided in the upper part of the peripheral wall surface located on the downstream side in the rotation direction of the impeller with respect to the portion communicating with the discharge port of the pump casing. To be achieved.

Further, in the submersible pump of the present invention, the impeller attached to the rotary shaft of the motor is arranged in the pump casing, and the fluid sucked into the pump casing by the rotation of the impeller is transferred to the pump casing. A submersible pump that discharges from a communicating discharge port, and an air vent hole is provided in the upper part of the peripheral wall surface of the pump casing, and inside the pump casing on the peripheral wall surface on the upstream side of the air vent hole in the rotation direction of the impeller. The inwardly projecting guide portion is provided adjacent to the air vent hole so as to guide the fluid flowing through to the inner peripheral side of the pump casing, thereby achieving the above object. To be done.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a longitudinal sectional view showing an example of an embodiment of a submersible pump according to the present invention. This submersible pump has a lower pump casing 10 in which an impeller 11 is disposed.
And a motor 20 arranged above the pump casing 10 to rotate the impeller 11.

The motor 20 has a cylindrical stator casing 21 having an axial center in a vertical state, a rotary shaft 23 inserted through the axial center portion of the stator casing 21, and a rotor 22 attached to the rotary shaft 23. Rotor 22
And a stator 24 attached to the stator casing 21 so as to surround the.

An oil casing 25 that covers the lower end surface of the stator casing 21 is provided at the lower end of the stator casing 21. The rotating shaft 23 penetrates through the central portion of the oil casing 25, and the oil casing 25 covers the periphery of the rotating shaft 23 that is inserted through the shaft center portion. The rotating shaft 23 is rotatably supported by a bearing 26 attached to the oil casing 25.
The lower end surface of the oil casing 25 is in an open state, and a seal bracket 29 that covers the lower end surface of the oil casing 25 is attached by a bolt 25a. The rotary shaft 23 extends through the central portion of the seal bracket 29 and extends inside the pump casing 10.

A mechanical seal 27 is fitted on the rotating shaft 23 inserted through the oil casing 25, and the oil casing 25 is filled with oil.

On the upper side of the stator casing 21, a motor cover 28 having an electric system housed therein is attached. A handle portion 28a for carrying the submersible pump is also provided in a state of protruding above the motor cover 28.

A right cylindrical impeller chamber 12 having an axis perpendicular to the vertical axis is provided in the upper part of the pump casing 10, and a hollow central part in the vertical direction bulges outward at the lower part. A disk-shaped pump chamber 13 is provided. Rotating shaft 23
The lower end of the penetrating through the seal bracket 29 enters the impeller chamber 12 provided in the upper part of the pump casing 10, and the impeller 11 is attached to the lower end thereof. The impeller 11 is located in the impeller chamber 12.

A suction port 15 is formed on the bottom surface of the pump casing 10 so as to face the rotary shaft 23.
A plurality of legs 17 for lifting the bottom surface of the pump casing 10 are provided at appropriate positions in the circumferential direction at a plurality of positions on the outer peripheral edge portion of the bottom surface of the pump casing 10.

FIG. 2 is a sectional view taken along the line AA of FIG. As shown in FIGS. 1 and 2, the pump chamber 13 of the pump casing 10 is provided with an outflow conduit portion 14 having a discharge port 14a at its front end surface. This discharge line 1
No. 4 extends tangentially to the pump chamber 13 of the pump casing 10 and is in a state of being slightly curved so that the discharge port 14a faces outward.

The impeller 11 arranged in the impeller chamber 12 of the pump casing 10 is moved by the motor 20 as shown in FIG.
The sewage is sucked into the pump chamber 13 from the suction port 15 provided on the bottom surface of the pump casing 10 by the rotation of the impeller 11. The sewage that is sucked into the pump chamber 13 and agitated by the rotation of the impeller 11 flows out into the discharge conduit 14 by the centrifugal force, and the discharge port 14 at the tip is discharged.
It is discharged from a.

An air vent hole 12b is provided in a peripheral wall surface 12a forming the impeller chamber 12 of the pump casing 10. The air vent hole 12b is provided in the upper part of the peripheral wall surface 12a at a proper distance from the discharge conduit 14 downstream in the rotational direction of the impeller 12. A guide portion 12c for guiding the fluid flowing in the pump casing 10 to the inner peripheral side of the pump casing 10 is provided on the peripheral wall surface 12a on the upstream side in the rotation direction of the impeller 11 with respect to the air vent hole 12b. Is provided adjacent to.
The inner peripheral surface of the guide portion 12c is inclined so as to sequentially protrude from the peripheral wall surface 12a along the rotation direction of the impeller 11, and the amount of protrusion is maximum in the portion close to the air vent hole 12b. . Further, it has a gentle inclined surface that bulges in an arc shape from the portion where the amount of protrusion is maximum to the air vent hole 12b.

In the submersible pump having such a structure, the impeller 11 arranged in the impeller chamber 12 of the pump casing 10 is rotated by rotationally driving the rotary shaft 23 of the motor 20. When the impeller 11 is rotated, sewage is sucked into the pump chamber 13 from a suction port 15 provided on the bottom surface of the pump casing 10. The sewage sucked into the pump chamber 13 is rotated by the rotation of the impeller 11,
3 is agitated, flows into the discharge conduit 14 by centrifugal force, and is discharged from the discharge port 14a.

At this time, the inside of the pump chamber 13 is indicated by an arrow A in FIG.
Since a part of the sewage flowing in the direction indicated by the arrow flows out into the discharge pipe line portion 14, the pressure at the downstream side of the discharge pipe line portion 14 in the rotation direction of the impeller 11 is larger than the discharge pipe line portion 14. The pressure becomes lower than the pressure at the upstream side of the impeller 11 in the rotation direction. Therefore, even in the impeller chamber 12 above the pump chamber 13, the pressure at the downstream side in the rotation direction of the impeller 11 with respect to the discharge conduit portion 14 becomes low, and the sewage in the pump chamber 13 becomes sewage. Even if it flows into 12, the sewage is suppressed from flowing out from the air vent hole 12b provided in the low pressure region.

Moreover, since the sewage flowing into the impeller chamber 12 is guided to the inner peripheral side of the impeller chamber 12 by the guide portion 12c, it is adjacent to the guide portion 12c on the downstream side in the flowing direction of the sewage. The sewage is suppressed from flowing into the air vent holes 12b arranged in the same manner.

Since the sewage is prevented from flowing into the air vent hole 12b in this manner, foreign matter mixed in the sewage does not get clogged in the air vent hole 12b. Therefore, even when the air enters the pump chamber 13 due to the decrease in the sewage water level, the air in the pump chamber 13 passes through the air vent hole 12b provided on the peripheral wall surface 12a of the impeller chamber 12 and is reliably discharged. Is discharged to the outside.

The shape of the guide portion 12c provided in the vicinity of the air vent hole 12b is not limited to the shape of the above embodiment, and for example, a semicircular cross section as shown in FIG. 3 (a). It may have a shape or a triangular cross section as shown in FIG. Further, as shown in FIG. 3C, the impeller chamber 1 is provided with a guide portion 12c having a rectangular cross section.
The key may be fitted to the two peripheral wall surfaces 12a.

[0025]

As described above, in the submersible pump of the present invention, since the air vent hole provided in the peripheral wall surface of the pump casing is located in the low pressure region in the pump casing, the fluid such as sewage is in the air vent hole. The air vent hole is prevented from being clogged with foreign matter.

Further, since the guide portion for guiding the fluid to the inner peripheral side of the pump casing is provided adjacent to the air vent hole on the side opposite to the flow direction of the fluid, the fluid is vented by the air vent hole. Is suppressed from entering inside,
The air vent hole is prevented from being clogged with foreign matter.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an example of an embodiment of a submersible pump of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

3 (a) to 3 (c) are cross-sectional views showing another embodiment of the guide portion used in the submersible pump of the present invention.

[Explanation of symbols]

 10 pump casing 11 impeller 12 impeller chamber 12a peripheral wall surface 12b air vent hole 12c guide part 13 pump chamber 14 discharge pipe line portion 14a discharge port 15 suction port 20 motor 22 rotor 23 rotating shaft 24 stator

Claims (2)

[Claims] 1. An impeller attached to a rotary shaft of a motor is disposed inside a pump casing, and the rotation of the impeller causes a fluid sucked into the pump casing to be discharged from a discharge port communicating with the pump casing. The submersible pump is characterized in that an air vent hole is provided in an upper part of a peripheral wall surface located on a downstream side in a rotation direction of the impeller with respect to a portion communicating with the discharge port of the pump casing. 2. An impeller attached to a rotating shaft of a motor is arranged in a pump casing, and the fluid sucked in the pump casing is discharged from a discharge port communicating with the pump casing by the rotation of the impeller. In a submersible pump, an air vent hole is provided in the upper part of the peripheral wall surface of the pump casing, and the fluid flowing in the pump casing is applied to the peripheral wall surface upstream of the air vent hole in the rotation direction of the impeller. A submersible pump characterized in that a guide portion projecting inward so as to be guided to the inner peripheral side of the is provided adjacent to the air vent hole.