JP2000018196A - Intermediate casing structure of pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To discharge foreign matters without being accumulated by forming a raised portion made of synthetic resin all over the corner portion formed by a circumferential wall and an end wall forming the generally cylindrical metal intermediate casing, the raised portion guiding the foreign matters discharged from the discharge port of the impeller to the opening in the intermediate casing. SOLUTION: In an intermediate casing 6 of a multi-stage underwater pump 1, a raised portion 20 made of synthetic resin is formed integrally all over a corner portion 19 formed by a peripheral wall 15 and a bottom wall 16 of the intermediate casing 6. Foreign matters such as sand taken in through a suction port 10 tend to be separated by hitting against the inner surface of the peripheral wall of the intermediate casing 6 so as to stay at the corner portion 19, when they are discharged from a discharge port 11 of an impeller 5. However, since this corner portion 19 is, by formation of the synthetic resin raised portion 20, similar to a state where foreign matters exceeding a certain extent are accumulated, the foreign matters do not stay at the corner portion 19. Instead, they are led to outside of the intermediate casing while being mixed into the discharging flow.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intermediate casing structure for a pump used for accommodating an impeller and constituting, for example, a multistage pump in which a plurality of impellers are arranged in series.

[0002]

2. Description of the Related Art A deep well submersible pump (multi-stage pump) used for pumping deep wells is provided with a substantially cylindrical metal intermediate casing containing an impeller inside in order to ensure high pumping performance. Are connected in series to each other, and the pressure is increased by pumping by impellers at each stage to sequentially raise water.

[0003] A filter (strainer) is installed at the suction port of a submersible pump for deep wells to prevent suction of large foreign substances. Inhales foreign substances together with Shimizu.

When the sucked foreign matter is discharged from a discharge port located on the outer peripheral portion of the impeller, it is separated by contact with the inner surface of the peripheral wall of the intermediate casing in each stage, and is separated from the lower side of the intermediate casing. When the water accumulates in the corners of the peripheral part (the corner formed by the peripheral wall and the bottom wall (corresponding to the end wall)) and exceeds a certain level, it is sucked into the suction port of the impeller in the next stage while being mixed with the discharge flow from the impeller. It is discharged outside.

However, foreign matter (sand or the like) accumulated in the intermediate casing is moved (turned) in the circumferential direction in the intermediate casing by the rotating impeller. For this reason, foreign matter (sand, etc.) may cut the lower corner (corner) of the intermediate casing, causing unnecessary wear of the intermediate casing or perforating the corner (corner) of the intermediate casing. There is.

Conventionally, as shown in FIG. 4, a metal intermediate casing a of a submersible pump for deep wells has a peripheral wall b.
A ring-shaped metal shielding plate e is fixed obliquely to the inner surface of the casing by welding at a corner portion d formed by the bottom wall c and a foreign material such as sand discharged from a discharge port g of the impeller f. That is, it is guided to the suction port h of the impeller of the next stage so that foreign matter such as sand does not accumulate at the corner d.

However, in the structure in which the corner portion d is shielded by the metal shielding plate e, a metal component (shielding plate e) having a shape suitable for shielding is prepared, and this metal component (shielding plate a) is welded. Since welding is performed on the inner surface of the casing, considerable man-hours are required until assembly, and the cost burden is large.

Therefore, recently, in consideration of the cost, resin molding performed together with the intermediate casing a is adopted to take measures to prevent wear of the corner portion d. Specifically, as shown in FIG. 5, a resin member i is applied to the inner surface of the bottom wall c so as to leave the corner portion d, and a ring-shaped groove portion j is formed on the inner surface of the bottom wall so as to follow the entire circumference of the corner portion d. And ribs k for blocking the inside of the groove portion j are formed at a plurality of positions in the circumferential direction of the groove portion j with a resin portion so that foreign matter (sand or the like) is deposited in the groove portion j so as not to turn ( Stop).

[0009]

However, such a structure in which a detent is formed by a resin member requires a considerable amount of time for resin molding, and a groove j / rib k around a corner d.
Since the resin is molded, the molding method is quite difficult.

For this reason, there is a demand for a technique capable of preventing wear of the intermediate casing in consideration of cost and formability. The present invention has been made in view of the above circumstances, and its purpose is to provide a structure that is inexpensive in cost and has excellent moldability, so that foreign matter does not accumulate from the discharge port of the impeller to the outside of the intermediate casing. It is an object of the present invention to provide an intermediate casing structure of a pump which can be discharged.

[0011]

According to a first aspect of the present invention, there is provided an intermediate casing structure, wherein a peripheral wall and an end wall which form a substantially cylindrical metal intermediate casing have an entire periphery around a corner portion. In addition, by forming a raised portion made of synthetic resin to guide foreign matter discharged from the discharge port of the impeller to the opening side of the intermediate casing, the corner portion in the raised portion,
In an environment similar to that in which foreign matter has accumulated in the corner part over a certain amount, foreign matter always discharged from the discharge port of the impeller is discharged to the outside of the intermediate casing while being mixed with the discharge flow discharged from the impeller. I made it.

This prevents foreign matter such as sand from accumulating on the corners of the intermediate casing. In addition, since the raised portion only needs to be formed of a synthetic resin over the entire periphery of the corner portion, the molding is simple, the molding is excellent, and the cost is low.

[0013] The intermediate casing structure according to claim 2 is
Furthermore, the surface of the synthetic resin raised portion is formed into a concave curved surface in order to allow the foreign matter and the discharge flow to flow through the raised portion.

[0014] The intermediate casing structure according to claim 3 is
In order to increase the rigidity of the raised portion with a more inexpensive structure, the synthetic resin raised portion is formed integrally with the synthetic resin flow channel formed on the end wall of the intermediate casing, and the flow channel is utilized. Thus, the rigidity of the raised portion made of synthetic resin is increased.

The intermediate casing structure according to claim 4 is
Furthermore, in order to improve the sand resistance of the sliding portion of the impeller by utilizing the raised portion, the outer periphery of the mouth portion forming the suction port of the impeller is formed in the synthetic resin portion connecting the raised portion and the flowing water channel portion. The liner ring that slides on the surface is incorporated.

[0016] The intermediate casing structure according to claim 5 is characterized in that:
For the intermediate casing in which the undercut portion is formed on the inner surface of the peripheral wall by the formation of the insertion portion, at an easy and inexpensive cost, in order to form a raised portion made of synthetic resin, the raised portion is Using a mold that partially escapes from the undercut portion of the peripheral wall, the synthetic resin member is built up at the corner portion of the intermediate casing, and then the synthetic resin portion that escaped to the undercut portion is removed and formed in a later process. It is in.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described based on one embodiment shown in FIGS. FIG. 1 shows the entirety of a pump to which the present invention is applied, for example, a multistage submersible pump installed in a deep well. In the drawing, reference numeral 1 denotes an elongated pump portion extending vertically, and 2 denotes a pump casing of the pump portion 1.

The pump casing 2 has an impeller 5 (impeller) housed between a metal suction casing 3 arranged at the lowermost stage and a metal discharge casing (not shown) arranged at the uppermost stage. A plurality of cylindrical intermediate casings 6 made of metal are arranged in series. And these casing groups are fastened by the fastening band 7 bridged between the suction casing 3 and the discharge casing.

A rotary shaft 8 is provided at the center of the pump casing 2 along the axial direction. This rotating shaft 8
An impeller 5 housed in each intermediate casing 6 is attached to an outer peripheral portion of the impeller. The lower end of the rotary shaft 8 is connected to an output shaft 9a of a submersible motor 9 (motor) attached to the suction casing 3 via a joint 9b, and rotational force is transmitted from the submersible motor 9 to the rotary shaft 8. And each impeller 5 rotates. That is, in each rotating impeller 5, fresh water (corresponding to a pumping fluid) of a well is sucked from a suction port 10 formed in a lower portion (corresponding to one side portion) of the impeller 5, and is supplied to the impeller 5. A pressure feeding step of discharging from a discharge port 11 formed in an outer peripheral portion of the liquid crystal display is performed. In other words, the fresh water sucked in by the impeller 5 of each stage is pumped out of the deep well while being sequentially increased in pressure.

The present invention is applied to the intermediate casing 6 of such a multistage submersible pump 1. The detailed structure of the intermediate casing 6 is shown in FIG. Describing the structure of the intermediate casing 6, the intermediate casing 6 includes a peripheral wall 15 surrounding the discharge port 11 of the impeller 5,
5 has a bottom wall 16 (corresponding to an end wall) extending from a lower end portion (one end portion) of the impeller 5 toward a mouth portion 10a forming the suction port 10 of the impeller 5, and is formed into a substantially cylindrical shape. is there. Specifically, the intermediate casing 6 is formed into a cylindrical shape so as to surround the impeller 5 by press molding. This intermediate casing 6
Is tapered so that the diameter dimension gradually decreases toward the tip, and the insertion portion 17
Is formed. An annular groove 1 that can be inserted into the insertion portion 17 is provided on the outer peripheral portion of the outer surface of the bottom wall 16 of the intermediate casing 6.
The intermediate casings 6 are formed in series by repeating the operation of inserting the insertion portion 17 into the groove portion 18 and positioning the plurality of intermediate casings 6 while positioning them.

The peripheral wall 15 and the bottom wall 1 of the intermediate casing 6
A raised portion 20 made of a synthetic resin, which is a main part of the present invention, is integrally formed on the entire periphery of the corner portion 19 formed by the base member 6.
As shown in FIG. 3A, the raised portion 20 has an undercut portion 21 (a portion having a smaller diameter dimension by δ in the figure) formed on the inner surface of the peripheral wall 15 by molding the insertion portion 17. By resin molding using a molding die 24 formed by a combination of the releasing mold members 22 and 23, a synthetic resin member is built up in a triangular cross section over the entire periphery of the corner portion 19, and FIG. As shown, a part of the synthetic resin member which escaped along the undercut portion 21 of the peripheral wall 15, that is, a synthetic resin portion which becomes a surplus (burr) is removed in a post-process after the resin molding [FIG. ) Indicates the synthetic resin portion to be removed]]. The size of the raised portion 20 is such that foreign matter discharged from the discharge port 11 of the impeller 5 is guided to the opening side of the intermediate casing 6, specifically, to the suction port 10 of the impeller 5 while mixing with the discharge flow. The corner portion 11 is set to a predetermined size that allows the behavior to be obtained, and the corner portion 11 has a pseudo environment similar to that in which a certain amount or more of foreign matter has accumulated. In addition, the surface of the synthetic resin member forming the hypotenuse of the raised portion 20 has a concave curved surface 20a that faces in the vertical direction.
The guide function performed on the curved surface 20a allows the discharge flow from the discharge port 11 of the impeller 5 to flow smoothly to the suction port 10 of the next stage impeller 5.

The raising portion 20 is provided at the suction port 1 of the impeller 5.
In order to guide the fresh water to zero, it is resin-molded integrally with the synthetic resin flowing water channel portion 25 formed on the lower surface of the bottom wall 16 of the intermediate casing 6 so that the number of parts does not increase unnecessarily. In addition, the guide vane 25 a
Is formed. Further, the raised portion 20 and the flowing water channel 2
A liner ring 26 that slides on the outer peripheral surface of the mouth portion 10a is incorporated into an annular synthetic resin portion 16a that is present on the inner peripheral portion of the bottom wall 16 and that is connected to the bottom wall 16. Thus, components as large as possible are incorporated into the bottom wall 16 of the intermediate casing 6.

The raised portion 20 allows foreign matter (sand, etc.) from the impeller 5 to be guided to the next stage impeller 5 together with the discharge flow of the impeller 5 without accumulating on the corner portion 19 of the intermediate casing 6. It is.

That is, when foreign matter such as sand sucked from the suction port 10 is discharged from the discharge port 11 of the impeller 5,
It is separated by contact with the inner surface of the peripheral wall of the intermediate casing 6 and tends to accumulate in the corner portion 19.

However, due to the formation of the raised portion 19 made of a synthetic resin, the corner portion 19 has an environment similar to that in which foreign matters have accumulated in a certain amount or more. For this reason, foreign matter (sand, etc.) discharged from the discharge port 11 of the impeller 5 does not accumulate in the corner portion 19 and mixes with the discharge flow of the impeller 5 and is outside the intermediate casing 6, that is, the next stage impeller. 5 is led to the suction port 10 side.

Therefore, foreign matter such as sand does not accumulate at the corner 19 of the intermediate casing 6. Moreover, since the raised portion 20 may be formed by resin molding in which only the synthetic resin is laid on the entire periphery of the corner portion 19, the forming is simple.
Excellent in moldability and cost.

In addition, since the surface of the raised portion 20 is formed into a concave curved surface 20a, foreign matters (such as sand) and the discharge flow flow smoothly, and even if the raised portion 20 is formed, the pump performance does not decrease. .

In addition, the rigidity of the raised portion 20 is increased by an inexpensive structure utilizing the flowing water channel 25 by integral molding with the flowing water channel 25 made of synthetic resin, and the reliability is high.
Further, by incorporating the liner ring 26 into the synthetic resin portion 16a connecting the raising portion 20 and the flowing water channel portion 25, sand resistance between the sliding portion of the impeller 5, specifically, the mouth portion 10 of the suction port 10, is provided. The performance can be significantly improved, and a decrease in pump performance can be minimized.

The raised portion 20 is formed by using a molding die 24 that avoids the inner surface of the peripheral wall of the intermediate casing 6, forming the synthetic resin member on the corner portion 19, and then making an excess in another step later. By adopting the step of removing the synthetic resin portion, the undercut portion 21, which is expected to be difficult to mold, can be easily and inexpensively provided to the intermediate casing on the inner surface of the peripheral wall 15, and the height of the raised portion 20 can be reduced. Can be formed. In one embodiment, the present invention is applied to a multi-stage submersible pump, but is not limited to this, and may be applied to a pump using another intermediate casing.

[0030]

As described above, according to the first aspect of the present invention, the corner portion of the intermediate casing has an environment similar to that in which foreign matters have accumulated more than a certain amount due to the raised portion, so that the impeller Foreign matter such as sand discharged from
Instead of being collected at the corners, it is discharged out of the intermediate casing while being mixed with the discharge flow discharged from the impeller.

Therefore, it is possible to prevent foreign matters such as sand from accumulating on the corners of the intermediate casing. In addition, since the raised portion may be formed by resin molding in which only the synthetic resin is laid on the entire periphery of the corner portion, the molding is simple, the moldability and the cost are excellent, and no load is imposed on the intermediate casing.

According to the second aspect of the present invention, in addition to the above-described effects, the foreign matter and the discharge flow can flow through the raising portion satisfactorily, and the pump performance does not decrease even if the raising portion is formed. .

According to the third aspect of the present invention, in addition to the above effects, the rigidity of the raised portion can be increased with an inexpensive structure, and the reliability can be improved. According to the fourth aspect of the present invention, in addition to the above-described effects, the sand resistance of the sliding portion of the impeller can be remarkably enhanced by utilizing the raised portion, and the deterioration of the pump performance can be minimized. Can be.

According to the fifth aspect of the present invention, in addition to the above-mentioned effects, the undercut portion, which is expected to be difficult to form, can be easily and inexpensively provided to the intermediate casing having the inner surface of the peripheral wall. This has the effect that a raised portion made of synthetic resin can be formed.

[Brief description of the drawings]

FIG. 1 is a half sectional view showing the structure of a pump according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view for explaining a structure of an intermediate casing of the pump.

FIG. 3 is a view for explaining a process until a raised portion is formed at a corner of the intermediate casing.

FIG. 4 is a cross-sectional view for explaining a structure for preventing accumulation of foreign matter used in an intermediate casing of a conventional pump.

FIG. 5 is a cross-sectional view for explaining a structure for preventing accumulation of foreign matter used in an intermediate casing of a different conventional pump.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Pump part 5 ... Impeller 6 ... Intermediate casing 10 ... Suction port 11 ... Discharge port 15 ... Peripheral wall 16 ... Bottom wall (end wall) 17 ... Insertion part 19 ... Corner part 20 ... Raising part 20a ... Curved surface 21 ... Undercut part 24 ... Molding die 25 ... Flow water channel part 26 ... Liner ring.

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Yasutaka Fujita 1-Gorita, Hashime-cho, Okazaki-shi, Aichi F-term in Okazaki Plant of Kawamoto Manufacturing Co., Ltd. 3H034 AA01 AA20 BB01 BB06 BB17 CC03 DD01 DD10 DD13 DD24 DD30 EE04

Claims (5)

[Claims] 1. A peripheral wall formed so as to surround a discharge port formed on an outer peripheral portion of an impeller, and one end of the peripheral wall is directed toward a suction port formed on one side of the impeller. A metal-made intermediate casing having a substantially cylindrical shape having an end wall formed so as to extend, and being laid over the entire periphery of a corner formed by the peripheral wall and the end wall, and discharged from a discharge port of the impeller. An intermediate casing structure for a pump, comprising: a synthetic resin raising portion formed so as to guide foreign matter to an opening side of the intermediate casing. 2. The intermediate casing structure for a pump according to claim 1, wherein the surface of the raised portion is formed as a concave curved surface. 3. An end wall of the intermediate casing has a flow path made of synthetic resin for guiding a fluid to be pumped to a suction port of the impeller, and the raised section is formed integrally with the flow path. The intermediate casing structure for a pump according to claim 1 or 2, wherein: 4. A synthetic resin portion connecting the raised portion and the flowing water channel portion includes a liner ring that slides on an outer peripheral surface of a mouth portion forming a suction port of the impeller. The intermediate casing structure for a pump according to claim 3, wherein: 5. The intermediate casing has an insertion portion having a reduced diameter formed at the other end of the peripheral wall, and an undercut portion formed on the inner surface of the peripheral wall by the insertion portion. The raised portion is formed by overlaying a synthetic resin member at the corner of the intermediate casing using a mold part of which has escaped from the undercut portion of the peripheral wall, and then surplus synthetic resin that escapes to the undercut portion. The intermediate casing structure for a pump according to claim 1, wherein the part is formed by removing a part in a later step.