JP2001115985A - Submerged motor pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light submerged motor pump in a simple structure, by improving suction performance of the pump by further reducing a flow loss of fluid in a pump casing and effectively cooling a submerged motor. SOLUTION: This submerged motor pump comprises a pump suction hole 28 opening over the substantially entire circumstance along the circumstantial direction, a pump casing 16 having an impeller 22 in it, a motor 18 that mounts impeller 22 to a projecting end of a shaft 20 and rotates it. The pump suction hole 28 is formed in a shape where an angle θ1 made by the center of flow line of fluid flowing in along the pump suction hole 28 at a cross section including the shaft 20 and the shaft 20 on the motor 18 side is set to be not more than 75 deg..

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a submersible motor pump which is mounted on a drainage pump truck which moves to a place without drainage equipment and drains water, and which is used at the site to put it into water and drain it. .

[0002]

2. Description of the Related Art For example, in a region where there is no drainage pumping station equipment at a junction of rivers flowing from a tributary to the main river, a rise in water level of the main river due to heavy rain or the like increases the tributary from the tributary to the main river. In some cases, natural drainage becomes impossible, and the internal water level rises, possibly causing flooding. In such a case, it is widely practiced to move a drainage pump vehicle equipped with a power generation facility and a submersible motor pump to the site, and to put the submersible motor pump mounted on the drainage pump vehicle into water to drain the water.

FIG. 4 shows a conventional general configuration of this type of submersible motor pump. A substantially cylindrical suction casing 10, a diffuser casing 12, and a discharge casing 14 are connected in series, and a pump casing 16 is formed. A submersible motor (motor) 18 is connected to an end of the pump casing 16 on the suction casing 10 side. The shaft 20 of the submersible motor 18 extends concentrically inside the pump casing 16, an impeller 22 is attached to a protruding end of the shaft 20, and a tip of the shaft 20 is provided inside the diffuser casing 12. The guide vane 24 is rotatably supported inside a boss portion of the guide vane 24 via an underwater bearing 26.

On the side surface of the suction casing 10, there is provided a pump suction port 28 which opens to the side over substantially the entire circumference along the circumferential direction thereof, and a rib 30 is disposed therein. . On the other hand, the discharge casing 14 is provided with a pump discharge port 32 that opens in the axial direction orthogonal to the streamline of the fluid flowing into the pump suction port 28. In other words, the angle θ between the center of the streamline of the fluid flowing into the pump suction port 28 and the shaft 20 is 90 ° in the cross section including the shaft 20.

[0005] Such a submersible motor pump is installed in a state of being suspended underwater such that a shaft 20 is horizontal by a float or the like, and is used by driving a submersible motor 18 and rotating an impeller 22. At this time, the fluid flows into the pump suction port 2
8 into the pump casing 16, flows into the impeller 22 with the flow direction changed by 90 ° inside the pump casing 16, and then passes through the guide vane 24 and is connected to the pump discharge port 32 (see FIG. (Not shown).

[0006]

However, in the prior art, the fluid sucked into the pump casing changes the direction of the flow by 90 ° inside the pump casing. Since the flow loss is small and fast, and the flow loss is proportional to the square of the flow velocity, not only the flow loss here is considerably large, but also the flow of the fluid generated by the operation of the pump. However, there is a problem that it cannot be effectively used for cooling the electric motor.

The present invention has been made in view of the above circumstances, and it has been made possible to improve the suction performance of a pump by reducing the loss of fluid flow in a pump casing and to effectively cool a submersible motor. Another object of the present invention is to provide a submersible motor pump that is structurally simple and lightweight.

[0008]

According to the first aspect of the present invention,
It has a pump casing having a pump suction port that is opened over substantially the entire circumference along the circumferential direction, and has a pump casing in which an impeller is arranged, and an electric motor that rotates the impeller by attaching it to a protruding end of a shaft. The pump suction port is formed in a cross section including a shaft, wherein the angle formed between the center of the flow line of the fluid flowing into the pump suction port and the shaft on the electric motor side is set to 75 ° or less. A submersible motor pump characterized in that:

Thus, the fluid sucked into the pump casing flows more smoothly inside the pump casing without suddenly changing its flow direction.
Fluid flow loss is reduced, and the motor is effectively cooled by the fluid flow generated around the motor as the pump operates.

According to a second aspect of the present invention, the pump suction port is formed so as to open to a side surface of a cylindrical suction casing constituting a part of the pump casing. It is a submersible motor pump of description.

According to a third aspect of the present invention, the pump suction port is formed in a truncated conical shape having a small diameter on the motor side and is opened on a side surface of a suction casing constituting a part of the pump casing. The submersible motor pump according to claim 1, wherein: Thereby, the flow of the fluid along the outer peripheral surface of the electric motor tends to occur with the operation of the pump.

According to a fourth aspect of the present invention, the pump suction port has the same diameter as the shaft on the motor-side end surface of a suction casing constituting a part of the pump casing having a truncated conical shape having a large diameter on the motor side. The submersible motor pump according to claim 1, wherein the submersible motor pump is formed so as to open in a direction. As a result, a fluid flow parallel to the axis of the electric motor is generated on the outer peripheral surface of the electric motor along with the operation of the pump to enhance the cooling effect of the electric motor, and the flow of the fluid changes twice inside the pump casing. However, by performing the first change of direction in a place where the area is relatively large and the flow velocity is the slowest, the loss due to the flow of the fluid is extremely small.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. The same members or corresponding members as in the conventional example shown in FIG.

FIG. 1 shows a submersible motor pump according to a first embodiment of the present invention. A substantially cylindrical suction casing 10 and a discharge casing 14 are connected in series to form a pump casing 16. A submersible motor (motor) 18 is connected to an end of the pump casing 16 on the suction casing 10 side. The shaft 2 of this underwater motor 18
No. 0 extends concentrically inside the pump casing 16, and an impeller 22 is attached to a protruding end of the shaft 20.
Further, the tip of the shaft 20 has an underwater bearing 26 inside a boss portion of a guide vane 24 provided inside the discharge casing 14.
It is rotatably supported via.

The suction casing 10 has a funnel-like body 40 having the same outer diameter and gradually decreasing in diameter in the direction of the discharge casing 14, and an inner peripheral surface 42a facing the funnel-like body 40. A ring-shaped body 42 formed in a / 4 arc shape is disposed at a predetermined distance from the ring-shaped body 42, and both are connected by a rib 30. Thereby, the suction casing 10 is opened over substantially the entire area along the circumferential direction of the side surface thereof, and the pump suction is divided by the surface 40 a of the funnel-shaped body 40 and the inner peripheral surface 42 a of the ring-shaped body 42. A mouth 28 is formed.

This pump suction port 28 has an angle formed by an extension line along the surface 40 a of the funnel-like body 40 and an extension line along the inner peripheral surface 42 a of the ring-like body 42 in a cross section including the shaft 20. open at 2.alpha, the angle theta ₁ between the center streamline of the fluid flowing into the pump inlet 28 through the center of the opening and the submersible motor 18 side shaft 20 of the following 75 °, for example 65 ° It is becoming. On the other hand, in the discharge casing 14, the pump discharge port 3 opening in the axial direction is provided.
2 are provided.

This submersible motor pump is installed in a state of being suspended underwater such that the shaft 20 is horizontal with a float or the like, and is used by driving the submersible motor 18 and rotating the impeller 22. Then, the fluid is sucked into the pump casing 16 from the pump suction port 28, flows into the impeller 22, and is drained from a drain hose (not shown) connected to the pump discharge port 32. At this time, the fluid sucked into the pump casing 16 changes its flow direction to the angle θ ₁ ,
That is, since it is necessary to change the angle by 75 ° or less, the fluid flows more smoothly inside the pump casing 16, thereby reducing the loss of the fluid flow. In addition, a flow of fluid is generated around the submersible motor 18 with the operation of the pump, and the submersible motor 18 is effectively cooled. Note that by smaller the angle theta _1, it is possible to further reduce the loss due to the flow of fluid.

FIG. 2 shows a submersible motor pump according to a second embodiment of the present invention.
The difference from this embodiment is that the funnel-shaped body 40 has an outer diameter smaller than the outer diameter of the ring-shaped body 42, and the suction casing 10 is shaped like a truncated cone having a smaller diameter on the underwater motor 18 side. It is in the point formed. According to this embodiment, the pump suction port 28 has a truncated conical suction casing 10.
, The flow of the fluid along the outer peripheral surface of the submersible motor 18 is likely to occur with the operation of the pump.

FIG. 3 shows a submersible motor pump according to a third embodiment of the present invention. In this embodiment, an external funnel 50 having a diameter gradually reduced toward the discharge casing 14 is provided. The inner funnel 52, which is one size smaller than the outer funnel 50, is disposed at a predetermined distance from the inner funnel 52, and the two are connected by the rib 30, so that the inner peripheral surface of the outer funnel 50 and the inner funnel 52 are connected. The suction casing 10 has a pump suction port 28 which is defined by an outer peripheral surface of the submersible motor 18 and is opened at substantially the entire circumference in the circumferential direction at the end surface on the side of the submersible motor 18. Other configurations are the same as those of the above embodiments.

Here, the pump suction port 28 is connected to the shaft 20.
And open in the same direction, in the cross section including the axis 20, the angle theta ₂ between the center streamline of the fluid and the submersible motor 18 side shaft 20 of the flowing along the pump inlet 28 is below 75 °, For example, it is set to 35 °.

According to this embodiment, a flow of liquid parallel to the shaft 20 is generated on the outer peripheral surface of the underwater motor 18 with the operation of the pump, and the cooling effect of the underwater motor 18 can be enhanced. Moreover, the liquid which has flowed from the open end of the pump inlet 28 to the inside, by an angle theta ₂ while flowing through the pump suction port 28 changes the angle of flow, further impeller 2
2, the flow angle is changed again by the angle θ ₂ , enters the impeller 22, passes through the guide vane 24 and the pump discharge port 3.
The water is drained by the hose connected to 2, but at this time, the first change of direction is a place where the area is large and the flow velocity is the slowest, so that the loss due to the fluid flow is extremely small.

This type of submersible motor pump is generally used by being suspended and installed in water so that the shaft 20 becomes horizontal via a float or the like. Is in the same direction as the axis 20,
There is no need to put the submersible motor pump deep into the water, and it can be used without inhaling air even in shallow places.

[0023]

As described above, according to the present invention,
The fluid sucked into the pump casing flows more smoothly inside the pump casing without abruptly changing the direction of the flow, whereby the loss of the fluid flow can be reduced and the pump performance can be improved. In addition, the motor can be effectively cooled by the flow of the fluid generated around the motor with the operation of the pump. Further, the structure is relatively simple and the weight can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a submersible motor pump according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a submersible motor pump according to a second embodiment of the present invention.

FIG. 3 is a sectional view showing a submersible motor pump according to a third embodiment of the present invention.

FIG. 4 is a sectional view showing a conventional submersible motor pump.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Suction casing 14 Discharge casing 16 Pump casing 18 Underwater motor 20 Shaft 22 Impeller 28 Pump suction port 32 Pump discharge port 40 Funnel-shaped body 40a Same as the above, Surface 42 Ring-shaped body 42a, Same as the inner peripheral surface 50 External funnel-shaped 52 Inside Funnel

Continued on the front page (72) Inventor Masahiro Kuramasu 11-1 Haneda Asahi-cho, Ota-ku, Tokyo F-term in Ebara Corporation (reference) 3H034 AA01 AA11 AA20 BB01 BB08 BB12 CC03 DD02 DD20 EE03 EE12 EE18

Claims (4)

[Claims] 1. A pump casing having a pump suction port which is opened over substantially the entire circumference along a circumferential direction, and an impeller is disposed inside the pump casing. The impeller is mounted on a protruding end of a shaft and rotated. The pump suction port has a shape in which the angle between the center of the streamline of the fluid flowing into the pump suction port and the shaft on the motor side is set to 75 ° or less in a cross section including the shaft. A submersible motor pump characterized by being formed. 2. The submersible motor pump according to claim 1, wherein the pump suction port is formed so as to open to a side surface of a cylindrical suction casing forming a part of the pump casing. 3. The pump suction port according to claim 1, wherein the motor side has a small diameter and is formed in a truncated conical shape with a small diameter, and is opened to a side surface of a suction casing constituting a part of the pump casing. A submersible motor pump as described. 4. The pump suction port is formed in the motor-side end face of a suction casing constituting a part of the pump casing in the shape of a truncated cone having a large diameter on the motor side and opening in the same direction as the shaft. 2. The method according to claim 1, wherein
A submersible motor pump as described.