JP2011252487A - Vertical shaft volute pump - Google Patents

Abstract

At least a part of a volute of a pump casing and a volute are produced by a can making a desired shape by joining a plurality of formed steel plates by forming a plate-shaped steel material into a predetermined shape by cutting and bending the steel plate A vertical-shaft centrifugal pump formed with a discharge pipe connected to the pipe.
SOLUTION: A vertical pipe 4, a main shaft 7 passing through the vertical pipe 4, an impeller 6 driven to rotate by the main shaft 7, a pump casing 2 housing the impeller 6, a pump casing 2 and a vertical pipe 4 are provided. And a discharge pipe 3 that constitutes a flow path for connecting the steel plate and a vertical shaft centrifugal pump, in which a plate-shaped steel material is cut into a predetermined shape and a plate-shaped steel material is cut out and bent into a predetermined shape At least a part of the volute of the pump casing 2 and the discharge pipe 3 connected to the volute were formed by using a can that obtains a target shape by joining a plurality of steel plates formed in the same manner.
[Selection] Figure 2

Description

  The present invention is configured such that a main shaft for rotationally driving an impeller housed in a pump casing passes through a vertical pipe, and a discharge pipe connected to a pump casing volute and a volute of fluid discharged from the impeller. In particular, it is related to a vertical spiral pump that is led to a vertical pipe through, and in particular, a plate-shaped steel material is formed into a predetermined shape in a process such as cutting and bending, and a desired shape is obtained by joining a plurality of the formed steel materials Thus, the present invention relates to a vertical shaft centrifugal pump in which at least a part of a volute of a pump casing and a discharge pipe connected to the volute are formed.

  There is a vertical shaft pump that pumps up the handling liquid by suspending the main shaft and piping that rotate the impeller in the suction water tank and pit barrel such as the intake pit, and immersing the pump body including the impeller and the suction port in the handling liquid. . As a kind of this vertical shaft pump, the main shaft that rotationally drives the impeller housed in the pump casing is configured to penetrate the vertical pipe, and the fluid discharged from the impeller is connected to the volute and volute of the pump casing There is a vertical spiral pump which is led to a vertical pipe through a discharge pipe. This vertical shaft centrifugal pump includes a volute that forms a spiral circumferential flow path around the impeller, and further includes a discharge pipe that changes the direction of the liquid to be handled from the volute to the vertical pipe and connects to the vertical pipe. Therefore, the shape becomes extremely complicated. Therefore, a pump casing (volute casing) including a volute, a discharge pipe, and a part of a vertical pipe are integrally formed by casting.

  FIG. 35 is a perspective view showing a discharge pipe integrated pump casing unit in which a pump casing, a discharge pipe, and a vertical pipe are integrally formed by casting. As shown in FIG. 35, the discharge pipe-integrated pump casing unit 101 includes a pump casing 102 having a volute, a pair of discharge pipes 103 and 103 extending upward from the left and right of the pump casing 102, and a discharge pipe. 103, and a vertical pipe 104 to which the upper ends of 103 are connected. In the example shown in FIG. 35, since the pump casing 102 is composed of a double volute casing (double spiral casing), a pair of discharge pipes 103, 103 are connected to the double volute.

  As shown in FIG. 35, in the pump casing 102, two volutes that are spirally spread outward in the radial direction are formed on a substantially annular casing body that is open on the inner peripheral side, and the pump casing 102 is a complicated complex having a large number of curved surfaces. It has a shape. The discharge pipe 103 is a pipe whose lower end is connected to the end of a spiral volute and whose upper end is connected to a cylindrical vertical pipe 104, and has a complicated shape having a large number of curved surfaces. In this way, each member has a complicated shape, and curved surfaces having complicated shapes are connected to each other at the connecting portions of adjacent members. Therefore, the discharge pipe integrated pump casing unit 101 is formed by integral molding by casting. Was making.

JP 2005-83232 A

  However, although it is easy to make a complicated shape by casting, there is a problem that if the shape is complicated like the discharge pipe integrated pump casing unit 101 shown in FIG. Since it is necessary to manufacture various mold molds, it takes a long time to manufacture, and there is a problem that the manufacturing cost increases when the number of manufactured units is small.

  In addition, in the integral molding by casting, due to restrictions on the shape of the casting, the wall thickness must be increased more than necessary, which not only wastes resources but also increases the material cost as the weight increases. There is a problem. And the total weight of a pump becomes large, and it is necessary to raise the intensity | strength of a pump installation part, and there also exists a problem that handling at the time of installation installation etc. requires a lot of labor. In addition, since the natural frequency decreases when the total pump weight is large, there is a problem that the possibility of causing resonance due to the excitation force accompanying the operation of the pump increases.

As described above, since the discharge pipe integrated pump casing unit integrally formed by casting has various problems, as described in Patent Document 1, the present inventors have established a vertical shaft axial flow pump, The idea is to apply a method of manufacturing a pump casing used in a vertical shaft mixed flow pump with a steel plate to a discharge casing integrated pump casing unit.
However, in the vertical shaft axial flow pump and the vertical shaft diagonal flow pump, the pump casing has a simple shape such as a substantially cylindrical shape or a barrel shape in which the body portion swells, and a press mold is required. Since it is about a guide vane, even if the pump casing is manufactured from a steel plate, the processing accuracy can be maintained and the manufacturing cost can be reduced.

  On the other hand, the vertical shaft centrifugal pump using the discharge pipe integrated pump casing unit as shown in FIG. 35 has a complicated shape for each part of the casing. Therefore, a large number of molds corresponding to each part are prepared. Must. In addition, such pumps are not mass-produced products, but are made to order, so the design must be optimized according to the specifications. Therefore, the discharge pipe integrated pump casing unit may have a different shape and size for each product, and it is very difficult to prepare a mold in accordance with them. On the other hand, it becomes difficult to form a single steel plate into a shape having a geometrically complicated curved surface without reducing the processing accuracy without using a mold.

  Accordingly, the present inventors cut and bend a plate-like steel material so that it can be manufactured regardless of the use of the mold for the main components of the discharge pipe integrated pump casing unit as shown in FIG. In this process, the problem of forming into a geometrically simple shape and forming with a can made to obtain a target shape by joining a plurality of steel plates formed into a simple shape is found.

  The present invention has been made in view of the above-mentioned circumstances, and can be formed into a predetermined shape by a process such as cutting out and bending a plate-shaped steel material, and a can made to obtain a target shape by joining a plurality of formed steel plates. Another object of the present invention is to provide a vertical shaft centrifugal pump in which at least a part of a volute of a pump casing and a discharge pipe connected to the volute are formed.

  In order to achieve the above-described object, the present invention provides a vertical pipe, a drive shaft that passes through the vertical pipe, an impeller that is rotationally driven by the drive shaft, a pump casing that houses the impeller, A vertical-axis centrifugal pump provided with a discharge pipe that constitutes a flow path connecting the pump casing and the vertical pipe, and cuts a plate-shaped steel material into a predetermined shape and cuts the plate-shaped steel material into a bending process By forming a desired shape by joining a plurality of steel plates formed into a predetermined shape by performing at least a part of the volute of the pump casing and a discharge pipe connected to the volute Features.

  The present invention relates to at least a part of a volute of a vertical shaft centrifugal pump and a discharge pipe that connects the volute and a vertical pipe, and cuts a plate-shaped steel material into a predetermined shape and cuts the plate-shaped steel material into a bending process. And forming a desired shape by joining a plurality of steel plates formed into a predetermined shape. As the plate-like steel material, a stainless steel plate, a carbon steel plate or the like is used, and the steel plates are joined by a fusion welding method including arc welding. In this case, a steel plate cut out from a plate-shaped steel material to have a predetermined shape and a steel plate cut out from the plate-shaped steel material and bent into a predetermined shape are used. A steel plate obtained by cutting out a plate-shaped steel material into a predetermined shape is a flat plate having a simple shape such as a substantially square shape or an annular shape, and the cut-out flat plate may be appropriately subjected to processing such as deburring, for example. . A steel plate obtained by cutting a plate-shaped steel material and bending it into a predetermined shape is a curved plate having a curved surface with a predetermined shape. For the bending process, a bending process is preferably used in which both sides of the steel sheet are supported by cylindrical rollers, and the steel sheet is bent into a predetermined shape by applying pressure to the steel sheet from above using a pressing member such as a pressing plate. The curved surface formed by bending is a curved surface with a simple shape such as a cylindrical surface or a conical surface, and the curved surface is a developable surface that can be developed into a flat surface without expanding and contracting.

In a preferred aspect of the present invention, at least a part of the volute is joined to a lower flat plate that defines the lower surface of the volute, an upper flat plate that defines the upper surface of the volute, and a side plate that defines the side surface of the volute. It is formed.
According to the present invention, a part of the volute is constituted by the upper and lower flat plates and the spirally shaped side plate that defines the outer peripheral surface of the volute, so that the structure of the volute becomes simple and the manufacture becomes easy.

In a preferred aspect of the present invention, a flow path cross-sectional area of a portion formed by the lower flat plate, the upper flat plate, and the side plate is determined only by a radial position of the side plate.
According to the present invention, since a part of the volute of the spiral pump is composed of upper and lower flat plates and a side plate that defines the outer peripheral surface of the volute, the flow passage cross-sectional area of the volute can be determined only by the radial position of the side plate. Design is simplified.

In a preferred aspect of the present invention, the lower flat plate and the upper flat plate are thicker than the side plates.
According to the present invention, since the thickness of the upper and lower flat plates constituting the volute of the spiral pump is increased, sufficient strength to withstand fluid pressure can be secured, and the side plate that defines the outer peripheral surface of the volute can be thin. Accordingly, the weight of the pump casing can be reduced.

In a preferred aspect of the present invention, the side surface of the volute is formed by arranging two side plates formed in a spiral shape at a rotationally symmetric position of 180 °.
According to the present invention, it is possible to form a double volute simply by arranging two side plates of the same shape formed in a spiral shape at a rotationally symmetric position of 180 °. It becomes easy. Similarly, a triple volute can be formed by arranging the three side plates at a rotationally symmetric position of 120 °, and a quadruple by arranging the four side plates at a rotationally symmetric position of 90 °. Since the volute can be formed, the production of the volute becomes extremely easy.

In a preferred aspect of the present invention, there is provided a steel plate that is joined to a flow direction end of the upper flat plate and that expands a flow passage cross-sectional area in a vertical direction while facing the lower flat plate.
According to the present invention, the steel plate is provided to expand the channel cross-sectional area in the vertical direction so as to face the lower plate of the volute of the spiral pump, so that the fluid pressure recovery section is provided without increasing the maximum outer diameter of the pump. be able to.

In a preferred aspect of the present invention, a circular lower ring is joined to the inner diameter side of the lower flat plate.
According to the present invention, since the thick circular lower ring is joined to the inner diameter side of the lower flat plate constituting the volute of the spiral pump, the strength can be maintained by the lower ring, and the suction bell mouth or the like can be bolted using the lower ring. It becomes possible to fasten by this, and a suction bell mouth etc. can be removed at the time of a maintenance.
In a preferred aspect of the present invention, a lower suction bell mouth and a lower liner ring portion are supported on the lower ring.

In a preferred aspect of the present invention, a circular upper ring is joined to the inner diameter side of the upper flat plate.
According to the present invention, since the thick circular upper ring is joined to the inner diameter side of the upper flat plate constituting the volute of the spiral pump, the strength can be maintained by the upper ring, and the suction bell mouth or the like can be bolted using the upper ring. It becomes possible to fasten by this, and a suction bell mouth etc. can be removed at the time of a maintenance.
In a preferred aspect of the present invention, the vertical spiral pump is a double suction centrifugal pump, and an upper suction bell mouth and an upper liner ring portion are supported on the upper ring.

In a preferred aspect of the present invention, the vertical shaft centrifugal pump is a single suction centrifugal pump, and the upper ring is provided with a shaft penetration portion through which the drive shaft passes, or a main shaft protection tube and an upper liner ring portion. It is provided.
According to the present invention, since the thick circular upper ring is joined to the inner diameter side of the upper flat plate constituting the volute of the spiral pump, the strength can be maintained by the upper ring, and the drive shaft (main shaft) can be utilized by utilizing the upper ring. A penetrating shaft penetrating portion can be provided, or a main shaft protecting tube and an upper liner ring portion can be provided.

In a preferred embodiment of the present invention, the steel plate cut out from the plate-shaped steel material into a predetermined shape is a flat plate, the steel plate cut out from the plate-shaped steel material and bent into a predetermined shape is a curved plate, The bending lines for forming the curved plate are straight lines and do not cross each other.
According to the present invention, it is possible to manufacture a discharge pipe that connects at least a part of a volute and the volute to a vertical pipe by joining a plurality of flat plates and a plurality of curved plates. In this case, the bending lines for forming the curved plate are defined so as to be straight and do not cross each other. Therefore, the curved surface formed by bending is a curved surface formed by moving a straight line, that is, a developable surface.

In a preferred aspect of the present invention, the curved plate is configured by a cylindrical surface or a conical surface, a part of the cylindrical surface or the conical surface, or a combination of the cylindrical surface and the conical surface.
According to the present invention, since the curved plate has a simple shape, bending is facilitated.

In a preferred aspect of the present invention, the steel plate at the lower end of the inner peripheral side portion of the discharge pipe has a curved surface corresponding to a portion of the side plate so that the lower end portion can be joined to the upper end of the side plate, and the other end portion Has a surface corresponding to a portion of the other steel plate so that it can be joined to another steel plate constituting the inner peripheral side portion of the discharge pipe.
According to the present invention, the lower end portion of the steel plate at the lower end of the inner peripheral side portion of the discharge pipe has an arc-shaped curved surface having the same curvature as the side plate formed in a spiral shape, and is smooth without a step difference from the side plate. It can be joined so that it becomes a smooth surface. And the other edge part of the said steel plate has a surface corresponding to the part of another steel plate so that it can join to the other steel plate which comprises the inner peripheral side part of the said discharge pipe.

In a preferred aspect of the present invention, the steel plate at the lower end of the inner peripheral side portion of the discharge pipe is constituted by a part of a conical surface, and the lower end portion of the steel plate is on an arc having the same curvature as the portion of the side plate to be joined. And the other end is on the same plane.
According to the present invention, the lower end portion of the steel plate at the lower end of the inner peripheral side portion of the discharge pipe can be joined to the spiral side plate so as to be a smooth surface without a step, and the other end of the steel plate The part can be joined so as to be a smooth surface without a step with the flat plate.

In a preferred aspect of the present invention, the steel plate at the lower end of the inner peripheral side portion of the discharge pipe is constituted by a part of a cylindrical surface, and the lower end portion of the steel plate is on an arc having the same curvature as the side plate portion to be joined. The other end portion is also on an arc having the same curvature as the side plate portion to be joined.
According to the present invention, the steel plate at the lower end of the inner peripheral side portion of the discharge pipe has an arc-shaped cylindrical surface with the same curvature from the lower end portion to the upper end portion.

In a preferred aspect of the present invention, a lower end portion of the vertical pipe is formed in a cylindrical shape having a closed lower end, and the discharge pipe is connected to a side surface and / or a bottom surface of the cylinder at the lower end portion of the vertical pipe. It is characterized by.
In a preferred aspect of the present invention, the lower end portion of the vertical pipe is configured in an inverted conical shape whose diameter decreases downward, and the discharge pipe is connected to the inverted conical surface of the lower end portion of the vertical pipe. It is characterized by.

In a preferred aspect of the present invention, a rectifying plate is attached in the discharge pipe.
According to the present invention, an elbow-shaped bent pipe, in particular, a bent pipe is provided by installing a rectifying plate on an elbow-shaped bent pipe connecting the outlet of the volute of the pump casing and the straight pipe of the discharge pipe. By dividing the inlet part of the path vertically by the baffle plate, the fluid flowing in the upper part of the pipe line at the inlet part of the bent pipe line does not flow toward the lower part of the pipe by drawing an arc larger than necessary, Flow separation can be prevented.

In a preferred aspect of the present invention, the volute channel has a substantially rectangular cross section.
According to the present invention, the flow path of the volute can be made into a simple shape, the volute can be easily manufactured, and the flow path design can be simplified.

In a preferred aspect of the present invention, the discharge pipe includes an inner peripheral side portion connected to the inner surface of the pump casing volute, an outer peripheral side portion connected to the outer surface of the pump casing volute, and an inner peripheral side portion. It is comprised from the both sides which connect an outer peripheral side part, The flow path of the said discharge pipe has the substantially square cross section, It is characterized by the above-mentioned.
According to the present invention, the flow path of the discharge pipe can be made into a simple shape, the manufacture of the discharge pipe is facilitated, and the flow path design can be simplified.

The present invention has the following effects.
(1) By forming at least a part of the volute of the volute pump and the discharge pipe connecting the volute and the vertical pipe with a can, the pump can be reduced in weight and the production cost can be reduced as compared with the production by casting. Can do.
(2) At least a part of the volute of the centrifugal pump and the discharge pipe connecting the volute and the vertical pipe are formed into a geometrically simple shape by a process such as cutting and bending a plate-shaped steel material. Since it was made by forming a can that obtains the desired shape by joining multiple steel plates formed into a shape, the shape of each steel plate can be simplified, making it easy to manufacture each steel plate and using a mold. Even if it is not used, it can be manufactured with high accuracy.
(3) Since a part of the volute of the spiral pump is composed of upper and lower flat plates and side plates that define the outer peripheral surface of the volute, the structure is simple and manufacture is easy. Moreover, since the flow path cross-sectional area of the volute can be determined only by the radial position of the side plate, the design is simplified.
(4) Since the plate thickness of the upper and lower flat plates constituting the volute of the spiral pump is increased, sufficient strength to withstand the fluid pressure can be secured, and the side plate that defines the outer peripheral surface of the volute can be made thinner. The weight of the casing can be reduced.
(5) Since the steel plate that extends the cross-sectional area of the flow path in the vertical direction is provided facing the lower flat plate of the volute of the spiral pump, a fluid pressure recovery section can be provided without increasing the maximum outer diameter of the pump. .
(6) Since a thick ring is joined to the inner diameter side of at least one of the upper and lower flat plates constituting the volute of the centrifugal pump, strength can be maintained by the ring and a suction bell mouth or the like can be fastened by a bolt using the ring. The suction bell mouth can be removed during maintenance.

FIG. 1 is a longitudinal sectional view showing an embodiment of a vertical shaft centrifugal pump according to the present invention. FIG. 2 is a cross-sectional view showing details of peripheral devices of the discharge pipe integrated pump casing unit, the impeller housed in the discharge pipe integrated pump casing unit, and the discharge pipe integrated pump casing unit. FIG. 3 is a perspective view showing the overall configuration of the discharge pipe integrated pump casing unit. FIG. 4 is a plan view of the discharge pipe integrated pump casing unit. 5 is a cross-sectional view taken along line VV in FIG. FIG. 6 is a side view of the discharge pipe integrated pump casing unit. FIG. 7 is a plan view showing the plate N that has been cut off. FIG. 8 is a plan view showing the plate M taken as a plate. FIG. 9 is a plan view showing the plate A that has been cut off. FIG. 10 is a plan view showing a plate J for forming the upper surface of the volute together with the plate M. FIG. FIG. 11 is a plan view showing the relationship between the lower flat plate and the side plate. FIG. 12 is a plan view showing the relationship between the upper flat plate and the side plate. FIG. 13 is a perspective view showing a state in which the plate J is further joined to the upper plate and the side plate shown in FIG. FIG. 14 is a plan view showing a plate F that has been cut based on the drawing. FIG. 15 is a plan view showing a plate G that has been cut off based on the drawing. FIG. 16 is a plan view showing a plate E that has been cut based on the plan drawing. FIG. 17 is an enlarged view of a main part of FIG. 3, and is a perspective view showing an inner peripheral side portion of the discharge pipe and a part of the pump casing formed by joining the plate F, the plate G, and the plate E. FIG. 18 is a plan view showing a plate B that has been cut based on the drawing. FIG. 19 is a plan view showing a plate C that has been cut based on the drawing. FIG. 20 is a plan view showing a plate D that has been cut based on the drawing. FIG. 21 is an enlarged view of the main part of FIG. 3, and is a perspective view showing a part of the outer peripheral side portion and the pump casing formed by joining the plate B, the plate C, and the plate D. FIG. 22 is a plan view showing a plate K that has been cut based on the drawing. FIG. 23 is a plan view showing a plate L that has been cut off based on the drawing. 24 is an enlarged view of a main part of FIG. 3, and is a perspective view showing a side part formed by joining the plates K and L and a part of the pump casing. FIG. 25 is a plan view showing a plate H that has been cut off based on the drawing. FIG. 26 is a plan view showing a plate I that has been cut based on the plan drawing. FIG. 27 is an enlarged view of the main part of FIG. 3, and a side part formed by joining the plates H and I, an outer peripheral side part formed by joining the plates B, C and D, and It is a perspective view which shows a part of pump casing. 28 is a cross-sectional view taken along line XXVIII-XXVIII in FIG. 4 and shows only the lower part of the discharge pipe. FIG. 29 is a plan view showing a plate P that has been cut based on the drawing. FIG. 30 is a plan view showing a plate O that has been cut based on the drawing. FIG. 31 is an enlarged view of a main part of FIG. 3, and shows a joint portion between a discharge pipe and a part of a vertical pipe formed by joining a plate P and a flat plate O formed in a cylindrical shape. It is a perspective view shown. 32 is a view showing a state where the impeller is arranged in the discharge pipe integrated pump casing unit manufactured through the above-described steps, and is a cross-sectional view taken along the line XXXII-XXXII in FIG. FIG. 33 is a perspective view showing an embodiment in which a rectifying plate is provided in the discharge pipe of the discharge pipe integrated pump casing unit shown in FIGS. 3 to 6 and ribs are provided on the outer surfaces of the pump casing and the discharge pipe. FIG. 34 is a view showing another embodiment of the vertical shaft centrifugal pump of the present invention, and is a schematic longitudinal sectional view showing the main part of the vertical shaft single suction centrifugal pump. FIG. 35 is a perspective view showing a discharge pipe integrated pump casing unit in which a pump casing, a discharge pipe, and a part of a vertical pipe are integrally formed by casting.

Hereinafter, an embodiment of a vertical spiral pump according to the present invention will be described with reference to FIGS. 1 to 34, the same or corresponding components are denoted by the same reference numerals, and redundant description is omitted.
FIG. 1 is a longitudinal sectional view showing an embodiment of a vertical shaft centrifugal pump according to the present invention. In FIG. 1, a vertical double suction centrifugal pump is shown. As shown in FIG. 1, the vertical shaft centrifugal pump of the present invention is fixed on a floor plate 111 covering a suction water tank 110 such as a water storage pit via an installation flange 112. The vertical spiral pump includes a discharge pipe-integrated pump casing unit 1 that hangs down in the suction water tank 110 and an impeller 6 disposed in the discharge pipe-integrated pump casing unit 1. The discharge pipe integrated pump casing unit 1 includes a pump casing 2 having a volute, a pair of discharge pipes 3 and 3 extending upward from the volute of the pump casing 2, and upper ends of the discharge pipes 3 and 3. The connected vertical pipe 4 is a main component. A pumping pipe 8 comprising a plurality of pipes having a circular cross section is flange-connected to the upper end of the vertical pipe 4, and the pumping pipe 8 extends upward from the discharge pipe integrated pump casing unit 1. A discharge elbow 5 is connected to the upper end portion of the water pump 8. The impeller 6 is composed of a double-suction centrifugal impeller, and a main shaft (drive shaft) 7 that rotationally drives the impeller 6 passes through the vertical pipe 4 and the pumping pipe 8 and is a wall portion of the discharge elbow 5. And is connected to a driving device (not shown) such as an electric motor.

FIG. 2 is a cross-sectional view showing details of the discharge pipe integrated pump casing unit 1, the impeller 6, and peripheral devices thereof. As shown in FIG. 2, the pump casing 2 connects the lower flat plate 21 that defines the lower surface of the volute casing, the upper flat plate 22 that defines the upper surface of the volute casing, the lower flat plate 21 and the upper flat plate 22, and the volute casing. The two side plates 23A and 23B that define the side surfaces of the two volutes (double volute) are provided. An annular lower ring 24 is joined to the inner diameter side of the lower flat plate 21, and a lower liner ring portion 25 and a lower suction bell mouth 26 are supported on the lower ring 24. An annular upper ring 27 is joined to the inner diameter side of the upper flat plate 22, and an upper liner ring portion 28 and an upper suction bell mouth 29 are supported on the upper ring 27.
Hereinafter, in the present embodiment, a case where the pump casing includes two volutes (double volute) will be described. However, the volute is not limited to a double volute, and may be a triple volute or a quadruple volute. In the case of a double volute, the two side plates are arranged at a rotationally symmetric position of 180 °. However, in the case of a triple volute, the three side plates are arranged at a rotationally symmetric position of 120 ° and 4 in the case of a quadruple volute. A plurality of volutes can be easily manufactured by arranging the side plates at 90 ° rotationally symmetrical positions.

  As shown in FIG. 2, a pair of discharge pipes 3, 3 are joined to two volute (double volute) portions of the pump casing 2. The discharge pipes 3, 3 extend upward, and the upper ends of the discharge pipes 3, 3 are joined to a cylindrical vertical pipe 4. The discharge pipe 3 is formed by joining a plurality of flat plates and curved plates, and a flow path is formed inside the discharge pipe 3. The lower end of the vertical pipe 4 is closed by a closing plate 41, and a bearing housing 42 that holds a bearing for rotationally supporting the main shaft 7 of the impeller 6 is fixed to the center of the closing plate 41. The vertical pipe 4 is connected to the pumped-up pipe 8 via the flange 43 (see FIG. 1). The discharge pipe-integrated pump casing unit 1 shown in FIG. 2 is suitable for a large pump having a diameter of the vertical pipe 4, that is, a discharge port diameter of φ600 mm or more. In other words, from the viewpoint of securing a working space when welding the inside, it is suitable for manufacturing a large-sized pump that allows an operator to put in the body and perform a work, particularly, a discharge port diameter (vertical pipe diameter) of φ600 mm or more. .

Next, a manufacturing process of the discharge pipe integrated pump casing unit 1 used in the vertical spiral pump shown in FIGS. 1 and 2 will be described with reference to FIGS.
FIG. 3 is a perspective view showing the overall configuration of the discharge pipe integrated pump casing unit 1. 4 is a plan view of the discharge pipe integrated pump casing unit 1, and FIG. 5 is a cross-sectional view taken along the line VV of FIG. FIG. 6 is a side view of the discharge pipe integrated pump casing unit 1.
As shown in FIGS. 3 to 6, the discharge pipe integrated pump casing unit 1 includes a pump casing 2 having a double volute and discharge pipes 3, 3 that form a pair extending upward from the volute of the pump casing 2. And the vertical pipe 4 to which the upper ends of the discharge pipes 3 and 3 are connected are the main constituent members. Main components of the discharge pipe integrated pump casing unit 1 are formed into a predetermined shape by a process such as cutting out and bending a plate-shaped steel material, and a can that obtains a target shape by joining a plurality of formed steel plates Molded. As the plate-like steel material, a stainless steel plate, a carbon steel plate or the like is used, and the joining is performed by a melt welding method including arc welding. In the following description, alphabets A to P will be given and described for plates formed through plate cutting, which is a step of cutting plate-shaped steel materials.

First, the manufacturing process of the pump casing 2 will be described. 7 to 13 are views for explaining a manufacturing process of the main part of the pump casing 2.
FIG. 7 is a plan view showing a plate N that has been cut based on the drawing. A plate N having a shape shown in FIG. 7 is cut out from a flat steel material having a thickness t1. The cut-out plate N is used as it is without bending and forms the lower flat plate 21. Note that the use of the cut plate as it is means that processing such as deburring may be performed as appropriate, but processing that changes the shape is not performed. The same applies to the following description. Since the pump casing 2 is a double volute casing, the plate N is provided with two outer peripheral edges Na and Nb that expand outward in the radial direction in a spiral shape. Connection portions between the two spiral outer peripheral edges Na and Nb are linear connection portions Nc and Nc. A circular hole is formed in the center of the plate N, and an annular lower ring 24 (see FIGS. 2 and 5) is joined to the circular inner peripheral edge Nd.

  FIG. 8 is a plan view showing a plate M that has been cut based on the plan drawing. A plate M having a shape shown in FIG. 8 is cut out from a flat steel material having a thickness t1. The cut plate M is used as it is without bending or the like to form the upper flat plate 22. The plate M is provided with two outer peripheral edges Ma and Mb that spread outward in the radial direction in a spiral shape. Connection portions between the two spiral outer peripheral edges Ma and Mb are linear connection portions Mc and Mc. The two spiral outer peripheral edges Ma and Mb have stepped portions Me and Me protruding outward in the radial direction by the thickness (t2) of the plate A at predetermined locations on the way to the joints Mc and Mc. The two spiral outer peripheral edges Ma and Mb expand from the stepped portions Me and Me in a spiral shape outward in the radial direction, and are connected to the connection portions Mc and Mc. A circular hole is formed at the center of the plate M, and an annular upper ring 27 (see FIGS. 2 and 5) is joined to the circular inner peripheral edge Md.

  FIG. 9 is a plan view showing the plate A that has been cut based on the drawing. Two plates A having the shape shown in FIG. 9 are cut out from a flat steel material having a thickness t2. The two cut out plates A are bent and formed into a spiral shape to form two side plates 23A and 23B that define the side surfaces of the two volutes (double volute). The plate N is joined to the lower end Aa of the plate A, and the plate M is joined to one flat portion Ab of the two flat portions Ab and Ac on the upper side of the plate A. Further, the stepped portion Ag between the two flat portions Ab and Ac is in contact with the stepped portion Me of the plate M. The plate A has inclined portions Ad and Ae at the top. Further, a protruding portion Af protruding upward is formed between the flat portion Ac and the inclined portion Ae. The thickness t1 of the plates M and N is set to be thicker than the thickness t2 of the plate A.

  FIG. 10 is a view showing a plate for forming the upper surface of the volute together with the plate M, and is a plan view showing a plate J cut off based on the drawing. Two plates J having the shape shown in FIG. 10 are cut out from a flat steel material having a thickness t2. The two cut-out plates J are used as they are without being bent to form the upper surface of the volute.

  FIG. 11 is a plan view showing the relationship between the lower flat plate 21 and the side plates 23A and 23B. As shown in FIG. 11, the lower ends of the two side plates 23 </ b> A and 23 </ b> B formed in a spiral shape from the plate A are joined to the lower flat plate 21 made of the plate N. The two side plates 23A and 23B formed in a spiral shape are rotationally symmetric with respect to the center O of the plate N so that when one of the two side plates 23A and 23B is rotated 180 °, it overlaps the other. It has become. The radius r from the center O of the two spiral spiral side plates 23A, 23B gradually increases as r1 <r2 <r3 <r4. The shape of the spiral can be expressed as r = f (θ) in polar coordinates (r, θ) using the radius r and the angle θ from the start end of the spiral. When joining the lower flat plate 21 made of the plate N and the side plates 23A, 23B, the outer peripheral surfaces of the side plates 23A, 23B and the spiral outer peripheral edges Na, Nb of the plate N are overlapped and joined. The side plate 23A extends along the spiral outer peripheral edge Na of the plate N, and the inner end portion 23Aie of the side plate 23A extends radially inward of the outer end portion 23Boe of the side plate 23B. The side plate 23B extends along the spiral outer peripheral edge Nb of the plate N, and the inner end 23Bie of the side plate 23B extends to the inside in the radial direction of the outer end 23Aoe of the side plate 23A.

  FIG. 12 is a plan view showing the relationship between the upper flat plate 22 and the side plates 23A and 23B. In FIG. 12, a part of the lower flat plate 21 is shown by phantom lines in order to clearly show the relationship between the upper flat plate 22 and the side plates 23A and 23B. As shown in FIG. 12, the upper flat plate 22 made of the plate M is joined to the two side plates 23A and 23B made of the plate A. That is, the flat portion Ab of the plate A contacts the lower surface of the outer peripheral edge Ma of the plate M, the stepped portion Ag of the plate A contacts the stepped portion Me of the plate M, and the plate A and the plate M are in contact with each other. Be joined. Further, the flat portion Ac, the projecting portion Af, and the inclined portion Ae of the plate A are located outside the outer peripheral edge Ma of the plate M, and the outer surface of the outer peripheral edge Ma of the plate M is in contact with the inner peripheral surface of the plate A. The plate A and the plate M are joined at the contact portion. Further, the inclined portion Ad of the plate A is exposed to the outside of the plate M.

FIG. 13 is a perspective view showing the case where the plate J is joined to the lower plate 21, the side plates 23 </ b> A and 23 </ b> B, and the upper plate 22 which are integrated and joined, and FIG. FIG. 13 (b) shows a state where the plate J is joined.
As shown in FIG. 13A, the lower flat plate 21, the side plates 23A and 23B, and the upper flat plate 22 are joined and integrated to form a part of the double volute. The flow path formed by the upper flat plate 22, the side plates 23A and 23B, and the lower flat plate 21 has a substantially square cross section, and the side plates 23A and 23B have a spiral radius and the radius r increases. The area gradually increases in the fluid flow direction. This flow path cross-sectional area is determined only by the radial positions of the side plates 23A and 23B.

As shown in FIG. 13A, when the lower flat plate 21, the side plates 23A and 23B, and the upper flat plate 22 are joined and integrated, the inclined portions Ad and Ae in the side plates 23A and 23B made of the plate A are radially inward. Parallel with the outside. Then, the inclined portions Ad and Ae of the parallel plates A have an upward slope as the radius r increases, and the height h of the side plate gradually increases as h1 <h2 <h3. As shown in FIG. 13B, the lower surface of the plate J is brought into contact with the inclined portions Ad and Ae of the side plates 23A and 23B, and the main portions of the double volute are formed by joining the contact portions. The flow path formed by the plate J, the side plates 23A and 23B, and the lower plate 21 has a substantially rectangular cross section, the side plates 23A and 23B are spirally wound, the radius r is enlarged, and the plate J is inclined upward. Therefore, the cross-sectional area of the flow channel increases in the radial direction and the substantially circumferential direction, and gradually increases in the fluid flow direction. This channel cross-sectional area is determined by the radial positions of the side plates 23A and 23B and the height h of the inclined portions Ad and Ae.
As described above, the main part of the pump casing 2 having a double volute is formed by forming the plate N, the plate M, the two plates A, and the two plates J into a predetermined shape and joining them. .

  Next, the manufacturing process of the discharge pipe 3 will be described. 14 to 28 are views for explaining the manufacturing process of the main part of the discharge pipe 3. The pair of discharge pipes 3 and 3 are rotationally symmetrical with respect to the axis of the main shaft 7 of the pump, and when one of the two discharge pipes 3 and 3 is rotated by 180 °, it overlaps the other. Therefore, only one discharge pipe 3 will be described below with reference to the two discharge pipes 3 and 3 that make a pair as appropriate.

  The discharge pipe 3 is defined as an element constituting a flow path connecting the pump casing 2 and the vertical pipe 4. On the other hand, the main part of the pump casing 2 is constituted by joining a lower flat plate 21 made of a plate N, an upper flat plate 22 made of a plate M, two side plates 23A and 23B made of a plate A, and two plates J. Is done. Since one plate material may partially constitute a pump casing and another portion may constitute a discharge pipe, in the following description, a member constituting a part of the pump casing 2 is referred to as a discharge pipe 3. It is included and explained. As shown in FIGS. 3 to 6, the discharge pipe 3 includes an inner peripheral side portion 3 a connected to the inner surface of the volute of the pump casing 2 and an outer peripheral side portion 3 b connected to the outer surface of the volute of the pump casing 2. And both side portions 3c and 3d connecting the inner peripheral side portion 3a and the outer peripheral side portion 3b. The discharge pipe 3 bends upward from the volute part of the pump casing 2 through an elbow-shaped bent pipe line, extends upward as a substantially straight pipe line at the middle stage part, and inclines slightly inward toward the vertical pipe 4 at the upper part. It has become a pipeline. The flow path formed by the discharge pipe 3 has a substantially rectangular cross section, and the flow path cross-sectional area is set so as to gradually increase along the fluid flow direction from the inlet side to the outlet side. That is, as shown in FIG. 5, the inclination of the inner peripheral side portion 3a toward the main shaft side is larger than the inclination of the outer peripheral side portion 3b toward the main shaft side. Since the difference between the inclination of the inner peripheral side portion 3a and the outer peripheral side portion 3b is thus made, the flow passage cross-sectional area of the discharge pipe 3 gradually increases from the inlet side toward the outlet side.

As shown in the discharge pipe on the left side of FIG. 3, the inner peripheral side 3 a connected to the inner surface of the volute of the pump casing 2 is composed of a plate F, a plate G, and a plate E.
FIG. 14 is a plan view showing a plate F that has been cut based on the drawing. A plate F having a shape shown in FIG. 14 is cut out from a flat steel material having a thickness t2. The cut plate F is bent along a bending line indicated by a two-dot chain line, and formed into a curved plate having a curved surface that constitutes a part of a conical surface. In this case, since the lower end Fa of the plate F is joined to the flat portion Ac (see FIG. 9) of the plate A, the lower end Fa of the plate F has the same curvature as the arc of the flat portion Ac of the plate A formed in a spiral shape. The arc is formed. Also, the substantially chevron-shaped outer peripheral edge Fb of the plate F has respective outer peripheral edges separated from the upper end of the outer peripheral edge Fb on the cut surface obtained by cutting a cone along a predetermined plane. , Located on each plane. And the straight line where each said plane crosses turns into a straight line which passes along the upper end of the outer periphery Fb. In addition, you may shape | mold so that an outer periphery on either side may be located on the same plane.
FIG. 15 is a plan view showing a plate G that has been cut off based on the drawing. A plate G having a shape shown in FIG. 15 is cut out from a flat steel material having a thickness t2. The cut plate G is used as it is without being bent.
FIG. 16 is a plan view showing a plate E that has been cut based on the plan drawing. A plate E having a shape shown in FIG. 16 is cut out from a flat steel material having a thickness t2. The upper part of the plate E has a substantially rectangular shape, and the lower part of the plate E has a substantially inverted triangular shape. Since the plate E is joined to the closing plate 41 that closes the lower end of the vertical pipe 4 at the upper end (see FIG. 3), the plate E is bent toward the closing plate 41 by bending at the upper portion. Molded into a curved plate bent inward.

FIG. 17 is an enlarged view of a main part of FIG. 3, and is a perspective view showing a part of the inner peripheral side portion 3 a and the pump casing 2 formed by joining the plate F, the plate G, and the plate E. As shown in FIG. 17, the lower end Fa of the plate F is joined to the flat portion Ac of the plate A formed in a spiral shape, the outer peripheral edge Fb on the left side of the plate F is joined to the plate E, and the right side of the plate F The outer peripheral edge Fb is joined to the plate G. The plate E has a flat shape without bending at the portion joined to the plates F and G, the plate G has a flat shape without bending, and the outer peripheral edge Fb of the plate F is on the same plane. Or the left and right edges of the outer peripheral edge Fb are on respective planes intersecting with a straight line passing through the upper end of the outer peripheral edge Fb, so that the joint between the plate E and the plate G is on the straight line. That is, when the left and right edges of the outer peripheral edge Fb are located on the respective planes, the straight line intersecting each of the planes passes through the upper end of the outer peripheral edge Fb, and this straight line is the junction between the plate F and the plate G. Match.
As shown in FIG. 2, the upper portion of the plate E is bent so as to have a curvature in the fluid flow direction, that is, in the vertical direction, and constitutes the inner peripheral side portion 3a. It is desirable for the inner diameter side of the flow path to cause fluid separation and to form a surface that is as smooth as possible in the flow direction. However, in this embodiment, the inner peripheral side portion 3a has a curvature in the fluid flow direction. By constituting, separation of flow is suppressed. This is in contrast to the fact that the outer peripheral side 3b, which will be described in detail later, is formed by connecting a plurality of surfaces having curvature in the direction perpendicular to the flow, that is, in the horizontal direction.
And the junction part of board E, F, G plays the role which changes the surface which has a curvature of a horizontal direction like the board F into the surface which can have a curvature in a perpendicular direction.
If the influence of the flow separation is small, the inner peripheral side portion 3a is formed by connecting a plurality of cylindrical surfaces having a curvature in a direction perpendicular to the flow, that is, a curvature in the horizontal direction, like the outer peripheral side portion 3b. Also good.

As illustrated in the discharge pipe on the right side of FIG. 3, the outer peripheral side portion 3 b connected to the outer surface of the pump casing 2 includes a plate B, a plate C, and a plate D. In addition, as for the board B, the upper part comprises a part of outer peripheral side part 3b, and the lower part comprises a part of pump casing 2. FIG.
FIG. 18 is a plan view showing a plate B that has been cut based on the drawing. A plate B having a shape shown in FIG. 18 is cut out from a flat steel material having a thickness t2. The cut-out plate B is bent into the x direction and formed into a curved plate having a curved surface that constitutes a part of the cylindrical surface. The right end Ba of the plate B extends in the vertical direction, and the upper end Bb of the plate B extends in the horizontal direction.
FIG. 19 is a plan view showing a plate C that has been cut based on the drawing. A plate C having a shape shown in FIG. 19 is cut out from a flat steel material having a thickness t2. The cut plate C is formed into a curved plate having a curved surface that forms a part of the cylindrical surface by bending in the x direction.
FIG. 20 is a plan view showing a plate D that has been cut based on the drawing. A plate D having a shape shown in FIG. 20 is cut out from a flat steel material having a thickness t2. The cut out plate D is bent along a bending line indicated by a two-dot chain line to form a curved plate having a curved surface that constitutes a part of the cylindrical surface.

  FIG. 21 is an enlarged view of a main part of FIG. 3, and is a perspective view showing a part of the outer peripheral side portion 3 b and the pump casing 2 formed by joining the plates B, C, and D. As shown in FIG. 21, the right end Ba of the plate B is joined to the end Ah of the plate A formed in a spiral shape. In FIG. 6, the joints (Ba, Ah) between the plate B and the plate A are clearly shown. Further, the upper end Bb of the plate B is joined to the plate C, and the upper end Ca of the plate C is joined to the plate D.

Next, both side portions 3c and 3d connecting the inner peripheral side portion 3a and the outer peripheral side portion 3b will be described.
As shown in the discharge pipe on the left side of FIG. 3, the side portion 3 c is composed of a plate K and a plate L. Note that the upper side of the plate K constitutes a part of the side part 3 c, and the lower side constitutes a part of the pump casing 2.
FIG. 22 is a plan view showing a plate K that has been cut based on the drawing. A plate K having a shape shown in FIG. 22 is cut out from a flat steel material having a thickness t2. The cut plate K is bent along a bending line indicated by a two-dot chain line to form a curved plate having a curved surface that constitutes a part of a conical surface. In FIG. 22, the upper end portion and the lower end portion of the plate K indicated by the alternate long and short dash line are not flattened and are flat plate portions.
FIG. 23 is a plan view showing a plate L that has been cut off based on the drawing. A plate L having a shape shown in FIG. 23 is cut out from a flat steel material having a thickness t2. The cut plate L is used as it is without being bent.

  24 is an enlarged view of a main part of FIG. 3, and is a perspective view showing a part of the side part 3c and the pump casing 2 formed by joining the plates K and L. FIG. As shown in FIG. 24, the lower end Ka of the plate K is joined to the upper end Ja of the plate J, and the upper end Kb of the plate K is joined to the lower end La of the plate L. Further, the inner peripheral side portion Kc of the plate K is joined to the inclined portion Ae and the plate E of the plate A, and the lower end side of the outer peripheral side portion Kd of the plate K is joined to the plate A and the upper side is joined to the plate B. . The joint between plate K and plate B is clearly shown in FIG. As shown in FIG. 24, the inner peripheral side portion Lc of the plate L is joined to the plate E, and the outer peripheral side portion Ld of the plate L is joined to the plate C and the plate D. The joint between the plate L, the plate C, and the plate D is clearly shown in FIG.

Further, as shown in the discharge pipe on the right side of FIG. 3, the side portion 3 d is composed of a plate H and a plate I. Note that the upper side of the plate H constitutes a part of the side part 3 d, and the lower side constitutes a part of the pump casing 2.
FIG. 25 is a plan view showing a plate H that has been cut off based on the drawing. A plate H having a shape shown in FIG. 25 is cut out from a flat steel material having a thickness t2. The cut plate H is formed into a curved plate having a curved surface that forms a part of the cylindrical surface by bending in the y direction on the lower side. The plate H is used as it is without being bent on the upper side.
FIG. 26 is a plan view showing a plate I that has been cut based on the plan drawing. A plate I having the shape shown in FIG. 26 is cut out from a flat steel material having a thickness t2. The cut plate I is used as it is without being bent.

  FIG. 27 is an enlarged view of a main part of FIG. 3, and an outer peripheral side portion formed by joining the side portion 3 d, the plate B, the plate C, and the plate D formed by joining the plate H and the plate I. It is a perspective view which shows a part of 3b and the pump casing 2. FIG. FIG. 28 is a cross-sectional view taken along line XXVIII-XXVIII in FIG. 4 and shows only the lower part of the discharge pipe 3. 27, the upper end Ha of the plate H is joined to the plate I, and the lower end Hb of the plate H is joined to the connection portion Nc of the plate N as shown in FIG. 27, the outer peripheral side portion Hc of the plate H is joined to the plate B, and the outer peripheral side portion Ic of the plate I is joined to the plate C and the plate D. Further, as shown in FIG. 28, the inner peripheral side portion Hd of the plate H is joined to the plates A and G, and the inner peripheral side portion Id of the plate I is joined to the plate E.

Next, the manufacturing process of the vertical pipe 4 will be described. FIGS. 29 to 31 are diagrams for explaining a manufacturing process of a portion of the vertical pipe 4 connected to the discharge pipe 3.
FIG. 29 is a plan view showing a plate P that has been cut based on the drawing. A plate P having a shape shown in FIG. 29 is cut out from a flat steel material having a thickness t2. Two notches Pa and Pb are formed in the plate P. The cut out plate P is bent in the x direction to be formed into a cylindrical shape, and the ends of the plate P are joined together to form the vertical pipe 4.
FIG. 30 is a plan view showing a plate O that has been cut based on the drawing. A plate O having a shape shown in FIG. 30 is cut out from a flat steel material having a thickness t3. On the outer periphery of the plate O, two arc-shaped portions Oa, Oa and two flat portions Ob, Ob are formed. A circular hole Oc is formed at the center of the plate O. The cut plate O is used as it is without being bent. The thickness t3 of the plate O is set to be thicker than the thickness t2 of the plate P.

  FIG. 31 is an enlarged view of a main part of FIG. 3, and a joint between the vertical pipe 4 and the discharge pipes 3, 3 formed by joining the plate P and the flat plate O formed in a cylindrical shape. FIG. As shown in FIG. 31, the plate P is formed into a cylindrical shape, and ends thereof are joined to form a cylindrical vertical pipe 4, and a plate O is joined to the lower end of the cylindrical vertical pipe 4 to form a vertical pipe. Close the lower end of 4. The plate O constitutes a closing plate 41. Thereby, two rectangular openings 4a (only one is shown in FIG. 31) are formed in the vertical pipe 4 by the two notches Pa and Pb formed in the plate P. In addition, a bearing housing 42 that holds a bearing for rotationally supporting the main shaft 7 of the impeller 6 is fixed in a circular hole Oc in the center of a closing plate 41 made of a plate O that closes the lower end of the vertical pipe 4 ( (See FIG. 2). As shown in FIG. 31, the upper ends of the plate D, the plate I, and the plate L of the discharge pipe 3 are joined to the vertical pipe 4 made of a plate P formed into a cylindrical shape, and the upper end of the plate E of the discharge pipe 3 is It is joined to a closing plate 41 made of a plate O. At this time, the plate D, the plate I, and the plate L are joined to the edge of the opening 4a of the vertical pipe 4, and the plate E is joined to the flat portion Ob of the plate O. In addition, as shown in FIG. 3, the flange 43 which consists of a cyclic | annular flat plate is joined to the upper end of the board | plate P shape | molded by the cylindrical shape, but illustration of the flange 43 is abbreviate | omitted in FIG.

As described above, the pump casing 2 having a volute is formed by a can making a desired shape by joining a plurality of formed steel materials by forming a predetermined shape in a process such as cutting and bending a plate-shaped steel material, and the like. , A discharge pipe integrated pump having a pair of discharge pipes 3 and 3 extending upward from the volute of the pump casing 2 and a vertical pipe 4 connected to the upper end of the discharge pipes 3 and 3 as main constituent members The casing unit 1 can be manufactured. A lower ring 24 is joined to the inner diameter side of the lower flat plate 21, and an upper ring 27 is joined to the inner diameter side of the upper flat plate 22. The lower ring 24 and the upper ring 27 are not made in cans but are manufactured by machining such as cutting. By manufacturing the lower ring 24 and the upper ring 27 by machining such as cutting, the strength of the pump casing 2 can be maintained, and the suction bell mouth or the like is fastened with bolts using the lower ring 24 and the upper ring 27. The suction bell mouth can be removed during maintenance.
Since the inner diameter of the lower ring 24 is larger than the outer diameter of the impeller, the impeller can be taken out from the lower end of the pump casing by removing the suction bell mouth fixed to the lower ring. Therefore, in this embodiment, the inner diameter of the upper ring 27 is smaller than the outer diameter of the impeller, and attachment to the upper ring such as a suction bell mouth may be a means that cannot be removed such as welding.

FIG. 32 is a view showing a state where the impeller 6 is arranged in the discharge pipe integrated pump casing unit 1 manufactured through the above-described steps, and is a cross-sectional view taken along the line XXXII-XXXII in FIG.
As shown in FIG. 32, two volutes 2 </ b> V and 2 </ b> V are formed on the outer peripheral side of the impeller 6 in the pump casing 2. The throat portions 2S, 2S of the double volute are constituted by inner end portions 23Aie, 23Bie of the side plates 23A, 23B and inner surfaces of the side plates 23A, 23B facing the inner end portions 23Aie, 23Bie.

FIG. 33 shows an embodiment in which a rectifying plate 50 is provided in the discharge pipe 3 of the discharge pipe integrated pump casing unit 1 shown in FIGS. 3 to 6 and ribs 51 are provided on the outer surfaces of the pump casing 2 and the discharge pipe 3. It is a perspective view.
The discharge pipe 3 bends upward from the volute part of the pump casing 2 through an elbow-shaped bent pipe line, extends upward as a substantially straight pipe line at the middle stage part, and inclines slightly inward toward the vertical pipe 4 at the upper part. It has become a pipeline. As shown in FIG. 33, a rectifying plate 50 is installed in an elbow-shaped bent pipe line that connects the outlet portion of the volute of the pump casing 2 and the straight pipe portion of the discharge pipe 3. The rectifying plate 50 is provided between the plate B and the plates A and F facing the plate B, and extends vertically from the inner surface of the plate B toward the plates A and F. Although the rectifying plate 50 is inside the plate B, in FIG. 32, the joint between the plate B and the rectifying plate 50 is indicated by a solid line. The rectifying plate 50 is formed by bending the two flat steel plates to form the plates Q and R having curved surfaces that respectively form part of the conical surface, and joining the plates Q and R together. It is produced by. The rectifying plate 50 is arranged so as to roughly bisect the flow path of the elbow-shaped bent conduit formed by the plate B, plate H, plate K, plate A, plate E, plate F, and plate G. As described above, the elbow-shaped bent pipe, in particular, the inlet of the bent pipe is divided into two by the rectifying plate 50 so that the fluid flowing in the upper part of the pipe at the inlet of the bent pipe is larger than necessary. An arc is drawn and does not flow toward the lower part of the pipe line or the outside of the bend of the flow path, so that separation of the flow can be prevented. The rectifying plate is not limited to a position where the bent pipe line is divided into two equal parts, and may be installed at a position closer to the inside of the bent where the flow is more easily separated. Moreover, it is not restricted to what is divided into two, You may make it provide two baffle plates and divide a flow path into three in the up-down direction.

Further, as shown in FIG. 33, reinforcing ribs 51 are joined to the outer surfaces of the pump casing 2 and the discharge pipe 3. The rib 51 is made of a steel plate having a substantially U-shape, and if necessary, the rib 51 is joined to the outer surface of the pump casing 2 and the discharge pipe 3 to which a high internal pressure is applied. The rigidity is increased. Thus, by joining the ribs 51 to the lower plate 21 and the upper plate 22 of the pump casing 2, the plate thickness of the lower plate 21 and the upper plate 22 can be reduced as well as the plate thickness of the side plates 23A and 23B. .
Further, in the discharge casing integrated pump casing of the present embodiment, the outer diameter becomes the largest from the rising part of the leg until the leg is bent inward to join. In this embodiment, the rib 51 provided in this portion is a U-shape excluding the portion corresponding to the outer peripheral side portion 3b of the leg as shown in FIG. The reason for this configuration is as follows. Such a vertical shaft pump is used by being suspended in a water tank, but in order to lower the pump into the water tank, the upper part must have a structure through which the pump can pass. In this structure, the cost increases as the outer diameter of the pump casing increases. Also, in the case of using a pit barrel, the larger the outer diameter of the pump casing, the larger the diameter of the barrel, which increases the cost. Therefore, a part of the rib does not protrude from the outer peripheral side portion 3b of the leg, and the outer diameter of the pump casing is reduced, which is advantageous in terms of cost.

FIG. 34 is a view showing another embodiment of the vertical shaft centrifugal pump of the present invention, and is a schematic longitudinal sectional view showing the main part of the vertical shaft single suction centrifugal pump. In FIG. 34, the case where a protective tube is provided and the case where a protective tube is not provided are shown. That is, in FIG. 34, the case where the protective tube 55 is installed on the left side across the center line of the main shaft 7 is shown, and the case where no protective tube is installed is shown on the right side. When the protective tube 55 is provided, the protective tube 55 is connected to the upper ring 27. When no protective tube is provided, a shaft penetrating portion 56 through which the main shaft 7 penetrates is connected to the upper ring 27. An upper liner ring portion 28 is supported on the upper ring 27.
In the vertical spiral pump shown in FIG. 34, the lower end portion of the vertical pipe 4 is closed by an inverted conical closing plate 57 whose diameter decreases downward. The upper end of the discharge pipe 3 is connected to the inverted conical surface of the inverted conical closing plate 57 at the lower end of the vertical pipe 4.

  Although the embodiment of the present invention has been described so far, the present invention is not limited to the above-described embodiment, and it is needless to say that the present invention may be implemented in various different forms within the scope of the technical idea.

DESCRIPTION OF SYMBOLS 1 Discharge pipe integrated pump casing unit 2 Pump casing 3 Discharge pipe 3a Inner peripheral side part 3b Outer peripheral side part 3c, 3d side part 4 Vertical piping 5 Discharge elbow 6 Impeller 7 Main shaft (drive shaft)
8 Pumping pipe 21 Lower flat plate 22 Upper flat plate 23A, 23B Side plate 24 Lower ring 25 Lower liner ring part 26 Lower suction bell mouth 27 Upper ring 28 Upper liner ring part 29 Upper suction bell mouth 41 Closing plate 42 Bearing housing 43 Flange 50 Current plate 51 Rib 55 Protective pipe 56 Shaft penetrating part 57 Closure plate 101 Discharge pipe integrated pump casing unit 102 Pump casing 103 Discharge pipe 104 Vertical piping A, B, C, D, E, F, G, H, I, J, K , L, M, N, O, P plate

Claims (21)

A vertical pipe, a drive shaft that penetrates the vertical pipe, an impeller that is rotationally driven by the drive shaft, a pump casing that houses the impeller, and a flow path that connects the pump casing and the vertical pipe A vertical spiral pump comprising a discharge pipe constituting
The said pump by the can manufacturing which obtains the target shape by joining the steel plate which cut out plate-shaped steel materials into the predetermined shape, and the steel plate which cut out plate-shaped steel materials, bent and formed in the predetermined shape An upright spiral pump characterized in that at least a part of a volute of a casing and a discharge pipe connected to the volute are formed.   At least a part of the volute is formed by joining a lower flat plate that defines the lower surface of the volute, an upper flat plate that defines the upper surface of the volute, and a side plate that defines the side surface of the volute. The vertical shaft centrifugal pump according to claim 1.   The vertical shaft centrifugal pump according to claim 2, wherein a flow path cross-sectional area of a portion formed by the lower plate, the upper plate, and the side plate is determined only by a radial position of the side plate.   The vertical shaft centrifugal pump according to claim 2 or 3, wherein a thickness of the lower flat plate and the upper flat plate is larger than a thickness of the side plate.   The side surface of the volute is formed by arranging two side plates formed in a spiral shape at a rotationally symmetric position of 180 °. Vertical shaft centrifugal pump described in 1.   6. The steel sheet according to claim 2, further comprising: a steel plate that is joined to a flow direction end of the upper flat plate and expands a cross-sectional area in a vertical direction while facing the lower flat plate. Vertical shaft centrifugal pump.   The vertical shaft centrifugal pump according to any one of claims 2 to 6, wherein a circular lower ring is joined to an inner diameter side of the lower flat plate.   The vertical shaft centrifugal pump according to claim 7, wherein a lower suction bell mouth and a lower liner ring part are supported by the lower ring.   The vertical shaft centrifugal pump according to any one of claims 2 to 8, wherein a circular upper ring is joined to an inner diameter side of the upper flat plate.   The vertical shaft centrifugal pump according to claim 9, wherein the vertical shaft centrifugal pump is a double suction centrifugal pump, and an upper suction bell mouth and an upper liner ring portion are supported by the upper ring.   The vertical shaft centrifugal pump is a single suction centrifugal pump, and the upper ring is provided with a shaft penetration portion through which the drive shaft penetrates, or a main shaft protection tube and an upper liner ring portion. The vertical shaft centrifugal pump according to claim 9.   In order to form the curved plate, the steel plate cut out from the plate-shaped steel material into a predetermined shape is a flat plate, and the steel plate cut out from the plate-shaped steel material and bent into a predetermined shape is a curved plate. The vertical shaft centrifugal pump according to any one of claims 1 to 11, wherein the bending lines are straight lines and do not cross each other.   The vertical shaft centrifugal pump according to claim 12, wherein the curved plate is configured by a cylindrical surface or a conical surface, a cylindrical surface or a part of a conical surface, or a combination of a cylindrical surface and a conical surface.   The steel plate at the lower end of the inner peripheral side portion of the discharge pipe has a curved surface corresponding to the side plate portion so that the lower end portion can be joined to the upper end of the side plate, and the other end portion is the inner periphery of the discharge pipe. The vertical-shaft centrifugal pump according to any one of claims 1 to 13, further comprising a surface corresponding to a portion of another steel plate so that the steel plate can be joined to another steel plate constituting the side portion.   The steel plate at the lower end of the inner peripheral side portion of the discharge pipe is composed of a part of a conical surface, the lower end portion of the steel plate is on an arc having the same curvature as the side plate portion to be joined, and the other end portion is 15. The vertical centrifugal pump according to claim 14, wherein the vertical centrifugal pump is on the same plane.   The steel plate at the lower end of the inner peripheral side portion of the discharge pipe is composed of a part of a cylindrical surface, the lower end portion of the steel plate is on an arc having the same curvature as the side plate portion to be joined, and the other end portion is also 15. The vertical spiral pump according to claim 14, wherein the vertical spiral pump is on an arc having the same curvature as a portion of the side plates to be joined.   The lower end portion of the vertical pipe is formed in a cylindrical shape whose lower end is closed, and the discharge pipe is connected to a side surface and / or a bottom surface of a cylinder at the lower end portion of the vertical pipe. The vertical axis | shaft centrifugal pump of any one of thru | or 16.   2. The lower end portion of the vertical pipe is formed in an inverted conical shape whose diameter decreases downward, and the discharge pipe is connected to an inverted conical surface of a lower end portion of the vertical pipe. The vertical axis | shaft centrifugal pump of any one of thru | or 16.   The vertical shaft centrifugal pump according to any one of claims 1 to 18, wherein a rectifying plate is attached in the discharge pipe.   The vertical shaft centrifugal pump according to any one of claims 1 to 19, wherein the flow path of the volute has a substantially rectangular cross section.   The discharge pipe connects the inner peripheral side portion connected to the inner side surface of the volute of the pump casing, the outer peripheral side portion connected to the outer side surface of the volute of the pump casing, and the inner peripheral side portion and the outer peripheral side portion. The vertical-shaft centrifugal pump according to any one of claims 1 to 20, wherein the vertical-shaft centrifugal pump is configured by both side portions, and the flow path of the discharge pipe has a substantially rectangular cross section.

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