JP3662633B2 - underwater pump - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a submersible pump, and more particularly, to a submersible pump effective for use in low-water level residual water drainage treatment.
[0002]
[Prior art]
Conventionally, submersible pumps for draining residual water have been used to treat low-level residual water such as pools and tanks. In this type of submersible pump, a suction port is opened in the bottom wall of the pump casing, and water at a low water level is sucked from the suction port through a strainer. The sucked water is pressurized by the impeller and is discharged to the outside of the pool and tank through the discharge passage and the like through the discharge pipe.
[0003]
[Problems to be solved by the invention]
However, when the water level gradually falls during the drainage operation and becomes lower than the bottom wall portion of the casing, air enters the pump through the suction port. This air collects in the spiral chamber. If air remains in the swirl chamber, the pressure of the pump may drop and pumping may become impossible. Even if the residual water level rises again, once it becomes impossible to pump the air, it is difficult for the air accumulated in the spiral chamber to be discharged outside the pump, and the amount of exclusion is very small, so it takes time to release the air to the outside. Resulting in. For this reason, it takes several tens of seconds or several minutes for the pump pressure to recover and re-pumping, or pumping may be impossible depending on the pumping height.
[0004]
The present invention has been made on the basis of the above circumstances, and an object thereof is to provide a submersible pump that discharges the air in the swirl chamber satisfactorily, recovers the pressure of the pump quickly, and can smoothly perform the draining operation. To do.
[0005]
[Means for Solving the Problems]
The invention of claim 1
A suction port is opened in the bottom wall, a spiral chamber having a central line in the vertical direction is formed in the interior, and a discharge passage communicating with the spiral chamber is formed in a side portion. A pump casing in which a draining portion is formed at a connection portion between the chamber and the discharge passage, a drive unit coupled to the pump casing, and an impeller housed in the spiral chamber and driven by power transmitted from the drive unit And extending along the discharge passage from the position on the extended line of the radius connecting the impeller center and the tip of the draining portion to the discharge passage to the vicinity of the discharge port. provided, the discharge passage includes a rib for partitioning a plurality of flow paths partitioned along the direction of rotation of said impeller, said pump casing the opening on the bottom of the casing main body The rib is covered with a removable bottom plate, and the rib is formed integrally downward on the casing body or a casing cover covering the upper surface of the casing body, and between the lower end of the rib and the bottom plate. A minute gap is formed .
[0007]
[Action]
According to the present invention, as a result of adopting the above configuration, the following operation occurs.
That is, according to the first aspect of the present invention, the air remaining in the spiral chamber is pushed around the impeller and the spiral chamber as the impeller rotates, and is rotated along with the rotation of the impeller. When such air reaches the discharge passage, it strikes the tip of the rib provided in the discharge passage and is guided to the outside through the discharge passage on the near side of the rib. Next, when the air layer reaches the draining portion of the discharge passage, the air layer hits the draining portion and is guided to the outside through the discharge channel on the back side of the rib. That is, since the air is guided to the discharge passage side at each of the rib tip and the draining portion, the discharge performance to the discharge port side is improved as compared with the case where the air is guided only by one conventional draining portion.
[0008]
In addition , since the rib is formed integrally downward on the casing body, even if a gap is generated between the lower end of the rib and the bottom plate, the air rejection performance is not adversely affected. In other words, when the pump casing has a structure in which the bottom plate is detachably divided, if the rib is erected on the bottom plate, the height of the rib may vary due to an error, and the upper end of the rib may be May not reach the top surface. In this case, a gap is formed in the upper part of the discharge passage, and since air is lighter than water, air may leak through this gap. On the other hand, if the rib is formed downward on the casing main body or the casing cover, even if a gap is generated between the lower end of the rib and the bottom plate, light air does not leak from here because the gap is at a lower position.
[0009]
On the other hand, if the height of the rib is higher than a predetermined value due to an error, the assembly of the bottom plate is hindered. On the other hand, if a minute gap is positively formed between the lower end of the rib and the bottom plate, even if there is an error in the rib height, assembly will not be hindered.
[0010]
【Example】
Hereinafter, the present invention will be described with reference to one embodiment shown in FIGS.
FIG. 1 is a sectional view showing the structure of the submersible pump, and FIG. 2 is a view of the submersible pump with the bottom plate removed as viewed from below.
[0011]
In FIG. 1, 1 is a pump part, 2 is a drive part.
The pump unit 1 includes a pump casing 3 and an impeller 4 accommodated in the pump casing 3 as main components.
The pump casing 3 includes a casing main body 10 whose upper and lower surfaces are open, a casing cover 11 that covers the upper surface of the casing main body 10, and a bottom plate 12 that covers the lower surface of the casing main body 10. A spiral chamber 13 is formed in a space surrounded by the casing body 10, the casing cover 11, and the bottom plate 12, that is, in the pump casing 3. The center line of the spiral chamber 13 is directed vertically. A suction port 14 is formed in the bottom plate 12, and the suction port 14 communicates with the center of the spiral chamber 13. A strainer 5 is attached below the bottom plate 12.
[0012]
A discharge passage 15 extending from the spiral chamber 13 toward the side is formed in the pump casing 3. The tip of the discharge passage 15 communicates with the discharge port 16, and the discharge pipe 6 is connected to the discharge port 16. A draining portion 17 is formed at a connection portion between the spiral chamber 13 and the discharge passage 15 at a portion from the winding start portion of the spiral chamber 13 toward the discharge passage 15.
[0013]
Further, a rib 18 is provided in the discharge passage 15. The rib 18 divides the discharge passage 15 into a plurality of flow paths 15a and 15b. The flow paths 15a and 15b are partitioned along the circumferential direction of the spiral chamber 13, and the downstream ends of the discharge paths 15 are discharged. It communicates with the outlet 16. The end portion of the rib 10 on the spiral chamber 13 side is substantially the same position as the winding start diameter of the spiral chamber 13, and the opposite end portion extends to the vicinity of the discharge port 16.
[0014]
In this embodiment, the discharge passage 15 is also surrounded by the casing body 10, the casing cover 11, and the bottom plate 12, and the rib 18 is formed on the casing cover 11 corresponding to the ceiling surface of the discharge passage 15. It is integrally formed. The rib 18 is suspended from the casing cover 11, and the lower end thereof is opposed to the bottom plate 12. A minute gap 19 is formed between the lower end of the rib 18 and the bottom plate 12, and the minute gap 19 is formed when the rib 18 is normally formed and the bottom plate 12 is normally assembled. It is designed to be about 5mm.
[0015]
The impeller 4 is rotatably accommodated in the spiral chamber 13. The impeller 4 is rotated by the power transmitted from the drive unit 2. The drive unit 2 is configured by housing a stator 22 and a rotor 23 in an electric motor housing 7 including an electric motor frame 20 and an electric motor cover 21 fixed to the upper end of the electric motor frame 20. A drive shaft 24 is connected to the rotor 23, and the drive shaft 24 is guided into the casing body 10 through the casing cover 11, and the impeller 4 is connected to the tip thereof. Therefore, when the drive unit 2 is operated, the impeller 4 is rotated.
[0016]
Due to the rotation of the impeller 4, the pressure in the center portion is lowered by the centrifugal force in the spiral chamber 13, so that water is sucked through the suction port 14 of the bottom plate 12. The sucked water is increased in pressure by the rotation of the impeller 4 in the spiral chamber 13 of the pump casing 3, guided to the discharge passage 15, and sent out from the discharge port 16.
[0017]
When the external water level is lowered and air is sucked in from the suction port 14 during operation of the submersible pump as described above, the air stays in the spiral chamber 13 and is difficult to be discharged outside the pump. However, since the rib 18 is provided in the discharge passage 15 in this example, the air release performance is improved.
[0018]
That is, the air remaining in the spiral chamber 13 is pushed around the spiral chamber 13 with the rotation of the impeller 4 and is rotated with the rotation of the impeller 4. When such air reaches the discharge passage 15, it hits the tip of the rib 18 positioned at the inlet portion of the discharge passage 15 and is guided to the outside through the discharge passage 15 a on the near side of the rib 18. Next, when the air layer reaches the draining portion 17 of the discharge passage 15, the air layer hits the draining portion 17 and is guided to the outside through the discharge passage 15 b on the back side of the rib 18. That is, since the air is guided to the discharge passage 15 side at a plurality of locations on the tip of the rib 18 and the draining portion 17, the removal performance to the discharge port 16 side is improved compared to the case where the air is guided only at one location of the conventional draining portion 17. To do.
[0019]
Further, since the rib 18 is formed downward integrally with the casing cover 11, even if a gap 19 is formed between the lower end of the rib 18 and the bottom plate 12, the air rejection performance is not adversely affected. That is, when the pump casing 3 has a structure in which the bottom plate 12 is divided, if the ribs 18 are erected on the bottom plate 12, the height of the ribs 18 may vary due to an error, and the upper end of the ribs 18 may The upper surface of the covering casing cover 11 may not reach. In this case, a gap is formed in the upper part of the discharge passage 15 and air is lighter than water, so that air may leak through this gap. On the other hand, when the rib 18 is formed downward on the casing cover 11, even if a gap 19 is generated between the lower end of the rib 18 and the bottom plate 12, light air leaks from the gap 19 because the gap 19 is in the lower position. There is no.
[0020]
On the other hand, if the height of the rib 18 is higher than a predetermined value due to an error, the assembly of the bottom plate 12 is hindered. On the other hand, if the minute gap 19 is positively formed between the lower end of the rib 18 and the bottom plate 12, even if there is an error in the height of the rib 18, the assembly is not hindered.
[0021]
If the position where the rib 18 is provided is too close to the impeller 4, the resistance during rotation of the impeller 4 is increased, and if it is too far from the impeller 4, the air cannot be guided well. For this purpose, it is desirable that the spiral chamber 13 is formed so as to extend in the direction of the discharge port 16 from substantially the same position as the diameter of the winding start.
[0022]
In the above embodiment, the rib 18 is integrally suspended from the casing cover 11. However, the discharge passage 15 is not necessarily formed by the casing body 10, the casing cover 11, and the bottom plate 12. . In other words, the left area shown in the figure with respect to the portion indicated by the imaginary line A in FIG. 1 is constituted by the casing cover 11, but the right area shown in the figure may be constituted by the casing body 10. And the bottom plate 12. In the pump having such a structure, the rib 18 may be formed integrally with the casing body 10.
In addition, this embodiment can be variously modified.
[0023]
【The invention's effect】
As described above, according to the first aspect of the present invention, when the water level is lowered and air enters from the suction port, the air can be discharged well by the guiding action of the rib provided in the discharge passage. Therefore, the pressure of the pump can be recovered quickly, and drainage work can be performed smoothly.
[0024]
In addition , when the bottom plate is detachable, a gap is positively formed between the lower end of the rib and the bottom plate. Therefore, even if there is a molding or assembly error, assembly of the bottom plate will not be hindered. Can be attached.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing the structure of a submersible pump.
FIG. 2 is a view of the submersible pump with the bottom plate removed as viewed from below.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Pump part 2 ... Drive part 3 ... Pump casing 4 ... Impeller 10 ... Casing main body 11 ... Casing cover 12 ... Bottom plate 13 ... Swirl chamber 14 ... Suction port 15 ... Discharge passage 15a, 15b ... Flow path 16 ... Discharge port 17 ... Drainer 18 ... Rib 24 ... Drive shaft

Claims (1)

A suction port is opened in the bottom wall, a spiral chamber having a central line in the vertical direction is formed in the interior, and a discharge passage communicating with the spiral chamber is formed in a side portion. A pump casing in which a draining portion is formed at a connection portion between the chamber and the discharge passage;
A drive unit coupled to the pump casing;
An impeller housed in the spiral chamber and driven by power transmitted from the drive unit;
Provided in the discharge passage so as to extend along the discharge passage from a position on an extended line of a radius connecting the center of the impeller, which is the diameter of the winding start of the spiral chamber, and the tip of the draining portion, to the vicinity of the discharge port. A rib that divides the discharge passage along the rotation direction of the impeller and divides the discharge passage into a plurality of flow paths ,
The pump casing is configured by covering the lower surface opening of the casing body with a detachable bottom plate, and the rib is integrally formed downward on the casing body or a casing cover covering the upper surface of the casing body. A submersible pump , wherein a minute gap is formed between the lower end of the rib and the bottom plate .

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