JP2847353B2 - underwater pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a submersible pump mainly used for construction work, in which a vortex impeller at an end of a motor shaft, that is, an impeller is retracted to a rear wall of a pump casing to form a wide gap in a front surface. The present invention relates to a submersible pump to which an impeller is mounted so as to carry out foreign matter such as sand along with a vortex generated in the space of the gap during operation of the pump.

[0002]

2. Description of the Related Art As shown in FIG. 7, a submersible pump mainly used for construction uses a semi-open impeller 1 having only a main plate without a shroud (side plate) on a suction side, as shown in FIG. And is housed in a pump casing 3 in which an intermediate casing (bracket) and a lower casing are integrally formed, and a small gap S ₁ (1-2 mm) with the front end face of the impeller 1 is maintained on the suction side. The suction cover 4 is attached. Below the suction cover 4, a bottom plate 6 is attached by bolts 7 via a cylindrical strainer 5. In the figure, 8 is a mechanical seal, and 9 is a lubricating oil.

[0003] During operation, the fluid sucked through the strainer 5 by the rotation of the impeller 1 is pressurized by the impeller 1 and discharged to the outside through the flow path 10.

[0004]

The above-mentioned conventional submersible pump has the following problems. (I) in need of modulation of the minute gap S ₁ of the impeller 1, maintenance takes time, and in order to manufacture the (ii) the flow passage 10 in the pump casing 3, shown in FIG. 8 (b) like,
In addition to the need for the upper core 10a for casting, as shown in FIG. 7A, there are also many processed parts (indicated by the symbol ▽ in the figure), and a great deal of labor is required in forming and processing. . Further, (iii) it was impossible to form the pump casing 3 from a wear-resistant rubber elastic body in terms of shape.

(Iv) At the time of disassembly, as shown in FIG. 9, even if the suction cover 4 is removed, the impeller 1
The interior is deep inside, so when replacing the impeller,
It was difficult to remove the blade, and a special jig was required.

(V) The pump casing 3 is worn,
When the casing was replaced, the mechanical seal 8 had to be disassembled to a normal one, and (vi) the internal lubricating oil 9 had to be discarded.

SUMMARY OF THE INVENTION An object of the present invention is to provide a submersible pump which solves the above-mentioned problems, is lightweight, has good durability, is easy to disassemble and assemble, and has good maintainability and productivity.

[0008]

In order to achieve the above object, the present invention provides a submersible pump in which a vortex impeller is attached to a motor shaft end, in which a pump casing is divided into an intermediate casing and a lower casing. The casing is made of a rubber elastic body and has an upper open shape, and the lower casing is provided with a plurality of legs as an integral structure,
The leg includes a lower end portion extending to the bottom plate, an outer peripheral side rib extending to the strainer position, and a bottom side rib extending radially inward and connected to the bottom of the lower casing. It is characterized by having been formed.

[0009]

According to the present invention, the outer peripheral rib formed on the leg abuts on the strainer to prevent the lower casing made of rubber elastic material from expanding and deforming radially outward due to the internal pressure of the lower casing.
The lower ends of the legs abut the bottom plate to prevent the lower casing from expanding and deforming outward in the axial direction. During operation, even if the pressure near the suction port becomes a negative pressure, the bottom rib extending inward in the radial direction acts to pull the suction port of the lower casing and its periphery to the outside of the pump chamber. Deformation of the periphery thereof being sucked into the pump chamber is prevented. As described above, since the deformation of the lower casing due to the internal pressure is prevented, leakage from the seal portion between the lower casing and the intermediate casing is prevented.

Further, since the heads of the bolts for attaching the intermediate casing to the motor are fitted into the recesses provided on the lower casing side with a narrow gap, expansion deformation of the lower casing is prevented.

During the operation of the pump, the fluid passes through the strainer and then passes through a suction passage formed between a plurality of legs protruding at an interval from each other and an outer surface of the lower casing and an upper surface of the bottom plate. The impeller is guided to the inlet, but the impeller is retracted so that the main plate approaches the intermediate casing, and is formed in a vortex shape having a wide gap formed on the front surface. Since foreign matters such as sand are carried out together with the vortex generated in the wide gap portion, wear of the impeller is reduced.

Further, the bolt provided at the position of the leg for holding the lower casing between the intermediate casing and the bottom plate prevents expansion deformation due to the internal pressure of the lower casing.
When the lower casing is clamped between the intermediate casing and the bottom plate by tightening the bolts, the tightening margin of the lower casing can be adjusted by members such as a sleeve and a strainer.

[0013]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1A is a longitudinal sectional view of a submersible pump showing one embodiment of the present invention, in which the same reference numerals as those shown in FIG. 7 indicate the same or similar parts.

Referring to FIG. 1A, a pump casing includes an intermediate casing (bracket) 11 and a lower casing 1.
2 and the intermediate casing 11 includes a motor 13
The bolt head 14a is attached to the recess 12a formed on the upper surface of the lower casing 12 with a narrow gap by means of a bolt 14. The lower casing 12 is connected to the conventional suction cover 4 (FIG. 7). It is integrated and made of rubber elastic body.

On the lower side (lower surface) of the lower casing 12, a plurality of legs 1 integrally formed with the lower casing are provided.
5 are provided. The leg 15 has a lower end 15b extending to the bottom plate 17 as shown in FIGS.
And an outer peripheral side rib 1 extending radially to an outer peripheral end 12 b of the lower casing 12 and extending to a position of the strainer 16.
5c and a bottom rib 15d extending radially inward and connected to the bottom of the lower casing 12.

A strainer 16 is attached to the legs 15 and the outer periphery 12c of the lower casing 12 so as to surround the entire side surface of the lower casing 12 with a small gap therebetween, and a bottom plate for supporting the strainer 16 and the lower casing 12 from below. 17, a bolt 18 extends through the leg 15 and the hole 18 a of the lower casing 12 and is screwed into the intermediate casing 11.
2. The strainer 16 and the bottom plate 17 are mounted together.

In a pump casing chamber formed by the intermediate casing 11 and the lower casing 12,
Vortex impeller 20, the main plate is retracted to the inner surface near the intermediate casing 11, is attached to form a wide gap S ₂ on the front surface (lower surface in the drawing) of the impeller 20,
Pump operation, to form a so-called vortex pump with a reduced wear of the impeller 20 so as to discharge the foreign materials such as sand with vortex flow generated in the space above the gap S ₂ parts.

In the drawing, reference numeral 19 denotes a through hole 1 of the bolt 18.
The sleeve inserted in 8a adjusts the interference between the lower casing 12 made of rubber elastic body and the leg 15 by tightening the bolt 18. In addition, strainer 16
This also contributes to the adjustment of the interference between the lower casing 12 and the legs 15. Reference numeral 21 denotes an impeller lock nut for preventing air lock.

Next, the operation will be described. (I) In general, when the lower casing 12 formed of a rubber elastic body is operated by a pump, the pressure distribution in the vertical section inside the casing is, as shown in FIG. 32 is a positive pressure. Thereby, as shown in FIG. 5B, the rubber elastic casing 12 has the suction port 12d sucked into the pump chamber, the pump outer wall 12e is pushed outward, and the suction port 12d hits the impeller 20, Due to the deformation of the outer wall 12e, a phenomenon occurs in which the pumped liquid in the pump leaks to the outside as indicated by an arrow 33. Therefore,
In order to prevent deformation, it is conceivable to add a special compounding material to increase the rubber hardness or to make the casing extremely thick, but as is generally known, when the hardness increases, the resistance increases. Abrasion is reduced, and as the thickness increases, the weight increases, resulting in higher material costs.

On the other hand, in the above-described embodiment, a plurality of radial legs 1
5 is provided on the leg 15 and the outer peripheral end 1 of the lower casing 12
An outer peripheral side rib 15c extending to 2b and integrally protruding;
The lower casing 12 extends radially inward and
The bottom side rib 15d connected to the bottom of the bottom casing 12 is formed, and the lower casing 12 is vertically sandwiched and fixed between the bottom plate 17 and the intermediate casing 11, so that as shown in FIG. The force of arrow f 'acts to prevent 12d and its peripheral part from being sucked into the pump as shown by arrow f. That is, the bottom side rib 15 d is
Since the suction port and its periphery are pulled to the outside of the pump chamber, deformation of the suction port and its periphery being sucked into the pump chamber is prevented.

(Ii) On the other hand, the outer periphery 1 of the lower casing 12
Since the strainer 16 is inscribed in the gap 2c narrowly and surrounds the entire side surface of the lower casing 12, the strainer 16
However, it receives the casing internal pressure expansion force F and prevents the casing 12 from being deformed by the reaction F '. By these deformation preventing actions, leakage from the seal portion 34 of the lower casing 12 and the intermediate casing 11 is prevented.

(Iii) Further, since the tightening bolt 18 of the lower casing 12 is screwed into the intermediate casing 11 through the through hole 18a of the lower casing, the bolt 18 prevents the internal pressure expansion of the pump from occurring inside. I have. Further, the mounting bolts 14 of the intermediate casing 11 and the motor 13 project toward the lower casing 12, and the lower casing recess 12
the bolt head 14a in a can, as shown enlarged in FIG. 1 (b), because it is inserted to narrow the gap S ₃ (fitting),
The expansion deformation of the casing 12 is prevented.

(Iv) On the other hand, the suction passage is formed by the space 15a between the plurality of legs 15 integrally formed on the lower side of the lower casing 12 and the outer surface 12f of the lower casing and the upper surface 17a of the bottom plate 17. During operation of the pump, the entire strainer 16 disposed on the outer periphery of the lower casing 12 has an effective suction area. Further, since the strainer 16 surrounds the entire lower casing as a casing expansion reinforcing material as described above, the strainer outer diameter (effective area) can be large, and even if there is clogging due to dust or the like, the effective area has a margin. As a result, there is no deterioration in pump performance.

(V) Next, at the time of disassembly and assembly of the submersible pump, as shown in FIG. 6, the bottom plate 17, the lower casing 12, and the strainer 16 can be disassembled only by removing the casing fastening bolts 18, and the above parts can be disassembled. When removed, the entire impeller 20 can be inspected. When replacing the impeller 20,
By inserting a commercially available pulley removal tool Y into the back side of the impeller main plate as shown in the figure and pulling it down in the direction of the arrow, the impeller 20 can be easily removed.

(Vi) Further, the wear of the lower casing 12 can be replaced without disassembling the mechanical seal 8 and without discarding the lubricating oil 9. When assembling, the mounting bolt head 14 of the intermediate casing 11 is used.
a engages with the recess 12a of the lower casing 12 by engaging with the recess 12a, and the positioning of the tightening bolt 18 with the intermediate casing 11 can be easily performed.
Assembly time is reduced.

According to this embodiment, the following effects are obtained. (I) Since the lower casing 12 has an open shape in which the upper side is opened, machining is unnecessary and productivity is improved. In addition, as shown in FIG. 4 (b), the scale removing tool X can remove the scale attached to the casing over the entire flow path from the upper side by using the scale removing tool X, and the lower casing 12 is separated from the motor 13 as a single unit. Also, the handling becomes simple.

(Ii) It is possible to prevent internal pressure expansion and deformation of the rubber elastic lower casing 12 by using standard parts such as the bottom plate 17, bolts 14, 18 and the strainer 16, so that a pressure-resistant structure can be obtained. Thereby, the hardness of the rubber elastic material can be made relatively soft, so that the wear resistance can be improved. In addition, the weight can be reduced.

(Iii) Since the pump casing has a divided structure of the intermediate casing 11 and the lower casing 12, inspection and replacement work of the impeller 20 are easy, and handling of the casing is simplified. There is no effect on the seal 8 and maintenance is easy.

In the above-described embodiment, the structure in which the legs 15 projecting from the lower side of the lower casing 12 are provided radially has been described. The outer ends of the legs 15 extend to the outer peripheral end 12b of the lower casing. It is sufficient that the fluid is guided at a distance from each other and guides the fluid to the pump suction port, and not necessarily in the radial direction.

[0030]

As described above, according to the present invention,
The following effects are obtained. (I) By dividing the pump casing into an intermediate casing and a lower casing, inspection and replacement of the impeller becomes easy, handling of the casing is simplified, and there is no influence on the mechanical seal when replacing the casing. Maintenance is easy. (Ii) By forming the divided lower casing into an upper open shape, it is possible to manufacture a rubber elastic body molded casing that does not require machining, thereby improving productivity.

(Iii) The outer peripheral rib formed on the leg abuts on the strainer to prevent the lower casing made of rubber elastic material from expanding and deforming radially outward due to the internal pressure of the lower casing, and the lower end of the leg contacts the bottom plate. In contact therewith, the lower casing is prevented from expanding and deforming outward in the axial direction. During operation, even if the pressure near the suction port becomes a negative pressure, the bottom rib extending inward in the radial direction acts to pull the suction port of the lower casing and its periphery to the outside of the pump chamber. Deformation of the periphery thereof being sucked into the pump chamber is prevented. Accordingly, even if the lower casing is made of a rubber elastic body, a sufficient pressure-resistant structure can be achieved, so that the hardness of the rubber elastic body can be made relatively soft. Therefore, the lower casing is made of a rubber elastic body. Thereby, the wear resistance of the casing is improved, and the weight can be reduced.

(Iv) The bolt head for attaching the intermediate casing to the lower end of the motor is fitted into the recess of the lower casing to not only prevent the lower casing from expanding and deforming, but also to tighten the lower casing during assembly. Positioning of the mounting bolt to the intermediate casing can be easily performed.

(V) Bolts provided at the legs for holding the lower casing between the intermediate casing and the bottom plate are:
It prevents expansion deformation due to the internal pressure of the lower casing. When the lower casing is clamped between the intermediate casing and the bottom plate by tightening the bolts, the tightening margin of the lower casing can be adjusted by members such as a sleeve and a strainer.

[Brief description of the drawings]

FIG. 1A is a longitudinal sectional view of a submersible pump showing an embodiment of the present invention, and FIG. 1B is an enlarged sectional view of a main part of FIG. 1A.

FIG. 2 is a top view of a lower casing.

FIG. 3 is a bottom view of the lower casing.

FIGS. 4A and 4B are explanatory views of a lower casing made of an elastic body.

FIGS. 5 (a), 5 (b) and 5 (c) are explanatory diagrams of the operation.

FIG. 6 is an explanatory view when disassembling the submersible pump of the present invention.

FIG. 7 is a longitudinal sectional view of a conventional submersible pump.

8 (a) and 8 (b) are explanatory views of a conventional pump casing at the time of manufacture.

FIG. 9 is an explanatory view of a conventional submersible pump when disassembled.

[Explanation of symbols]

 2 Motor shaft 11 Intermediate casing 12 Lower casing 12a Recess 12b Lower casing outer peripheral end 12c Lower casing outer peripheral 13 Motor 14 Bolt 14a Bolt head 15 Leg 15b Lower end 15c Outer side rib 15d Bottom side rib 16 Strainer 17 Bottom plate 18 Bolt 20 Vortex impeller

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁶ , DB name) F04D 13/08 F04D 29/42

Claims (4)

(57) [Claims] 1. A submersible pump in which a vortex impeller is attached to an end of a motor shaft, wherein a pump casing is divided into an intermediate casing and a lower casing, and the lower casing is formed of a rubber elastic body and has an upper open shape.
The lower casing is provided with a plurality of legs in an integral structure, and the legs have a lower end portion extending to a bottom plate, an outer peripheral side rib extending to a strainer position, and a radially inwardly extending portion. And a bottom rib connected to the bottom of the lower casing. 2. The method according to claim 1, wherein a head of a bolt for attaching the intermediate casing to a lower end of the motor is protruded toward a lower casing, and a concave portion is provided in the lower casing so that the bolt head enters a narrow gap. A submersible pump as described. 3. A bolt for clamping the lower casing between the intermediate casing and the bottom plate is provided at the position of the leg,
2. The submersible pump according to claim 1, wherein the bolt prevents expansion of the lower casing due to internal pressure. 4. A submersible pump according to claim 3, wherein a member for adjusting a tightening margin of the lower casing is provided when the lower casing is clamped between the intermediate casing and the bottom plate by tightening the bolts. .