JPH0361700A - Volute pump casing made of sheet metal - Google Patents

Abstract

PURPOSE:To restrain the deformation of the liner portion of a casing to the minimum when an excessive external force is exerted on a suction flange by radially interposing a plurality of vertical ribs between a rib support plate secured to the outer surface of a casing cell, and a suction flange. CONSTITUTION:A casing cell 1 is deeply drawn by pressing a piece of stainless steel sheet or the like, and is provided with a stationary flange 2 integrally formed at one end, and a suction port 3 opening toward the other end. A rib support plate 25 is secured to the shoulder portion 1d of the casing cell 1, and vertical ribs 26 are interposed between the rib support plate 25 and a suction flange 10. An external force exerted on the suction flange 10 is transmitted to a stationary flange 2 through the vertical ribs 26, the rib support plate 25, and the shoulder portion 1d of the casing cell 1, and is not transmitted to the outer surface of the casing cell 1. Accordingly, the partition portion 20a of a partition 20 is free from deformation, thereby preventing a liner ring 22 from being brought into contact with the end 5a of an impeller 5.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a sheet metal centrifugal pump casing, and particularly to a spiral pump casing made of a sheet metal, and in particular, a method for suppressing deformation of a part of the liner of the casing even when an external force is applied to the suction flange. This invention relates to a spiral pump casing made of sheet metal.

[Conventional technology]

Generally, a spiral pump casing made of sheet metal is known, which is made by deep drawing two sheets of stainless steel plate using a press to form a casing having a suction port, and a suction flange is fixed to the suction port of the casing shell. There is.

Since this type of centrifugal pump casing is made of sheet metal, it tends to be weak in strength, and when an external force is applied to the suction flange, this external force is directly transmitted to the casing acid, causing part of the liner to deform. There is a risk that this may occur. When a part of the liner deforms, it hits the impeller, which causes problems such as noise and pump overload, and even causes the casing shell to come into contact with the impeller, causing damage to the impeller. This may lead to unexpected situations.

In order to prevent this, conventionally, a partition is provided inside the casing shell to separate the suction chamber and the pressure chamber, and a part of the casing shell extending outside the partition is provided with a so-called flexible It has been proposed that a free structure is adopted, and when the above-mentioned external force is applied, only a part of the casing shell is deformed by the free structure, and this deformation does not extend to the partition body.

In addition, from another point of view, a reinforcing member is placed between the suction flange and the casing acid to create a so-called rigid structure, and the external force acting on the suction flange is directly transmitted to the casing acid. Some proposals have been made that allow the liquid to be absorbed by itself.

[Problem to be solved by the invention]

However, the so-called flexible free structure has a problem in that when connecting the suction pipe to the suction flange, the suction pipe itself must be supported with another member to the foundation.

In addition, with a so-called rigid structure, there is no problem under normal conditions, but if an excessive external force that cannot be absorbed by the casing acid is applied to the suction flange, a part of the liner of the casing shell will deform, causing the above-mentioned problem. There is a problem that hits occur.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned problems of the conventional technology and to minimize deformation of a part of the liner of the casing even when an excessive external force is applied to the suction flange. The object of the present invention is to provide a spiral pump casing made of sheet metal.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a spiral pump casing in which a suction flange is fixed to a suction boat of a casing shell integrally formed by deep drawing a steel plate using a press. A rib support plate is fixed to the outer surface of the casing shell, and a plurality of vertical ribs are radially interposed between the rib support plate and the suction flange.

[For production]

According to the present invention, even if an external force is applied to the suction flange, this external force reaches the fixed flange through the vertical ribs and the rib support plate, and therefore does not reach the outer surface of the casing shell. Deformation can be kept to an extremely low level, and if the rib support plate is supported in a floating state from the outer surface of the casing shell, this external force will hardly reach the outer surface of the casing shell.
Even if the suction flange is deformed due to the action of an external force, the casing acid is less likely to be deformed, and contact between the liner ring and the end of the impeller can be reliably avoided. Furthermore, if the vertical ribs are formed by bending a stainless steel plate or the like into a substantially U-shape, the entire structure can be made lightweight and highly rigid.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a spiral pump casing made of sheet metal according to the present invention will be described below with reference to the accompanying drawings.

In the first article, 1 indicates a casing acid of a centrifugal pump, and this casing acid 1 is formed by deep drawing a stainless steel plate or the like using a press. A fixed flange 2 is integrally formed at one end of the casing acid 1, and a suction port 3 is opened at the other end of the casing acid 1. This casing acid 1 is connected by a fixed flange 2 to a motor bracket (not shown) or the like.

A volute chamber A extending in the circumferential direction is formed in the center inside the casing acid 1, and the outer periphery of the volute chamber A is defined by an overhanging portion 1a. This overhang 1a
is formed by bulging the outer circumferential wall of the casing acid 1 outward in the radial direction, and the height of the bulging is determined by starting the bulging from the middle and moving in the circumferential direction (counterclockwise in the figure), as shown in FIG. direction)
It rises continuously along the Thereby, the flow passage cross-sectional area of the volute chamber A gradually increases in the direction of fluid flow.

An impeller 5 is provided inside the housing acid 1 and is integral with a boss 6 , which is connected to the free end of the main shaft 7 . A shaft sealing device 8 is attached to the main shaft 7, and this shaft sealing device 8 is supported by a casing cover 9 fixed to the casing acid 1.

The wall on the suction side of the casing acid 1 consists of a first wall part 1b and a second wall part 1c that are integrally formed, and the first wall part 1b has a shoulder IC outside to increase rigidity. The second wall portion 1 has a substantially S-shaped cross section and protrudes toward the second wall portion 1.
c is formed in a tapered shape toward the suction boat 3. A suction flange 10 formed by press as a separate member is connected to the outer edge of the second wall 1c by welding, and a suction port connected to the suction boat 3 is provided in the center of the suction flange 10. 11 is open.

A sealing surface 12 for connecting a companion flange (not shown) is formed on this suction flange 10, and a reinforcing flange 13 is fixed to the back side of this sealing surface 12. The suction flange 10 has four bolt holes 14.
As is clear from FIG. 2, four through holes 15 are formed in the reinforcing flange 13 in alignment with the bolt holes 14.

A partition body 20 having a substantially V-shaped cross section is fixed to the inner surface of the first wall part 1b of the casing acid (2), and a cylindrical partition part 20a is integrally formed in this partition body 20. ing. A liner ring 22 having a substantially L-shaped cross section is disposed on the inner periphery of the partition portion 20a at its flange portion 22a.
The liner ring 22 is press-fitted to a position where it contacts the partition body 20, and the end portion 5a of the impeller 5 is loosely fitted into the inner periphery of the liner ring 22. The above-mentioned chamber A and the suction side chamber are separated by the liner ring 22 of the partition portion 20a.

Further, a rib support plate 25 formed in a hollow ring shape is fixed to the shoulder portion 1d of the casing acid 1 so as to face the suction flange 10. This rib support plate 25 is disposed approximately parallel to the suction flange 10, and the portion other than the peripheral edge of the rib support plate 25 fixed to the shoulder portion 1d is the first wall portion 1b. It is supported in a floating state. This rib support plate 25 and the suction flange 10
Four vertical ribs 26 are interposed radially between the two, and the joint portions of the vertical ribs 26 are firmly welded. As is clear from FIG. 2, these vertical ribs 26 are formed by bending a steel plate into a substantially U-shape, and between the rib support plate 25 and the suction flange 10, It is interposed so that its opening 26a faces radially inward.

Furthermore, as is clear from FIG.
One end of the nozzle 7 is fixed, and a discharge flange 28 is fixed to the other end of the nozzle 27, and a discharge port 29 is opened in the center of the discharge flange 28. The structure of the discharge flange 28 itself is the same as that of the suction flange 10, so a description thereof will be omitted.

Next, the operation of the centrifugal pump made of sheet metal according to this embodiment will be explained.

A main shaft 7 is connected to a drive motor (not shown), and when the main shaft 7 is rotated, the impeller 5 rotates integrally with the main shaft 7, and fluid is sucked from the suction boat 3. This sucked fluid passes through the inside of the impeller 5, is given a centrifugal force, and is discharged into the volute chamber A from its outer periphery. This discharged fluid moves in the circumferential direction (counterclockwise in FIG. 2) within the volute chamber A, passes through the nozzle 27, and is discharged from the discharge port 29 of the discharge flange 28.

According to this embodiment, even if an external force acts on the suction flange 10, this external force reaches the fixed flange 2 through the vertical rib 26, the rib support plate 25, and the shoulder 1d of the casing acid 1. Moreover, this rib support plate 25
is supported in a floating state from the outer surface of the casing acid 1, so this external force does not reach the outer surface of the casing acid 1, and therefore does not directly reach the partition body 20.

Therefore, even if the suction flange 10 is deformed due to the action of an external force, the deformation will not be applied to the partition portion 20a of the partition body 20, and the liner ring 22 and the end portion 5a of the impeller 5 will not be deformed.
Contact between the two can be reliably avoided. Furthermore, since the vertical ribs 26 are formed by bending a stainless steel plate or the like into a substantially U-shape, they are lightweight and have high rigidity, so they can be made sufficiently strong.

Furthermore, since the partition body 20 is disposed inside the casing acid 1 and the liner ring 22 is attached to the partition part 20a of this partition body 20, even if the suction flange 10 is tilted, the tilt will be prevented. It hardly affects the partition part 20a directly, and this also causes the partition part 20 of the partition body 20 to
Deformation of a can be reliably prevented.

Furthermore, according to this embodiment, a volute chamber A is provided in the center of the casing acid 1, the flow path area of which gradually increases in the circumferential direction.
, the pump performance is greatly improved. Also,
Since the first wall portion 1b of the casing acid 1 has a shoulder portion 1d that projects outward and has a cross section approximately shaped like the letter S, various effects such as greatly increasing the rigidity of the casing acid 1 can be obtained. be able to.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, a rib support plate is fixed to the outer surface of the casing shell facing the suction flange, and a plurality of vertical ribs are radially arranged between the rib support plate and the suction flange. By interposing the suction flange, the rigidity of the suction flange can be increased, and even if an excessive external force is applied to the suction flange, deformation of the casing shell can be minimized.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a sheet metal centrifugal pump casing according to the present invention, and FIG. 2 is a front view of the same. 1...Casing acid, 3...Suction port, 5...
Impeller, 10... Suction flange, 20... Partition body, 20a... Partition part, 22... Liner ring, 2
5... Rib support plate, 26... Vertical rib.

Claims (1)

[Scope of Claims] 1. In a spiral pump casing in which a suction flange is fixed to a suction port of a casing shell integrally formed by deep drawing a steel plate using a press, the casing shell facing the suction flange is A spiral pump casing made of sheet metal, characterized in that a rib support plate is fixed to the outer surface, and a plurality of vertical ribs are interposed radially between the rib support plate and the suction flange. 2. The sheet metal centrifugal pump casing according to claim 1, wherein the vertical rib is formed by bending a steel plate into a substantially U-shape.