JPH0347499A - Volute pump casing made of sheet metal - Google Patents

Abstract

PURPOSE:To reduce the deformation of a casing by forming a casing-suction-side into an end-plate-shape, fixing an inner wall of a double-ring-shaped suction flange to a peripheral part of an inlet port, fixing an outer wall of the flange to the end-plate- shaped outer surface, and forming a gap between the suction side and a suction port of a partition body situated between a suction chamber and a pressure chamber. CONSTITUTION:An end part of a casing shell 1 is bent and formed into an end-plate shape, while a suction flange 10 is formed into a double-ring-shape having both an inner peripheral wall 10b and an outer peripheral wall 10c. The inner peripheral wall 10b is fixed to a peripheral part 1c of a port 3, while the outer peripheral wall 10c is fixed to the end-plate-shaped, outer surface 1b of the casing shell 1. As a result, rigidity of the casing shell 1 is heightened and its deformation is lessened. Meanwhile, a partition body 20, which separates a suction chamber B from a pressure chamber A, is arranged at the inside of the casing shell 1, and a diffuser 20b is formed as an extension at the suction-side-end of the partition body 20. In addition, a gap 21 is formed between the end-brim of the diffuser 20 and the periphery of the suction port 3. Accordingly, even if the outer force acts on the suction flange 10, the partition body 20 will not deform.

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, in which a casing acid having a suction boat is formed by deep drawing two sheets of stainless steel plate, etc., and a suction flange is fixed to the suction boat of the casing acid. There is.

This type of centrifugal pump casing tends to be weak in strength, and if an external force is applied to the suction flange, there is a risk that this external force will be directly transmitted to the casing acid, causing part of the liner to deform. . When part of the liner deforms, it hits the impeller, which causes noise and noise.
Problems such as pump overload may occur, and furthermore, the casing acid may come into contact with the impeller, leading to unexpected situations such as damage to the impeller.

In order to prevent this, conventionally, a partition is provided inside the casing acid to separate the suction chamber and the pressure chamber, and a part of the casing acid extending outside the partition is provided with a so-called soft It has been proposed that a free structure is adopted, and when the above external force is applied, only a part of the casing acid is deformed by this 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 portion of the casing acid liner may become deformed, 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 completely suppress deformation of a part of the liner of the casing even when an excessive external force is applied to the suction flange. An 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 steel plate is deep drawn using a press to form a casing acid having a suction port, and a suction flange is fixed to the suction port of the casing acid. The suction side end of the casing acid is curved into a mirror plate shape, and the suction flange is formed into a double ring shape with an inner peripheral wall and an outer peripheral wall, and the inner peripheral wall is fixed to the peripheral edge of the suction port. The outer peripheral wall is fixed to the mirror plate-like outer surface of the casing acid, and a partition is provided inside the casing acid to separate the suction chamber and the pressure chamber. A diffuser having an edge tapering toward the periphery is integrally installed, and an axial gap is formed between the edge of the diffuser and the periphery of the suction port. .

[For production]

According to the present invention, the suction side end of the casing acid is curved into a mirror plate shape, and the suction flange is formed into a double ring shape having an inner circumferential wall and an outer circumferential wall. Since it is fixed to the peripheral edge of the boat and the outer peripheral wall is fixed to the mirror plate-like outer surface of the casing acid, the rigidity of the casing acid is increased and it can be made with less deformation. A partition is provided to partition the suction chamber and the pressure chamber, and a diffuser having an edge tapering toward the periphery of the suction port is integrally extended at the suction side end of the partition. Since an axial gap is formed between the edge of the diffuser and the periphery of the suction boat, even if an external force acts on the suction flange, the external force will be transmitted to the fixed flange through the casing acid. Therefore, the partition will not be deformed, and even if the suction flange were to tilt, the edge of the diffuser and the periphery of the suction boat will not come into contact with each other, so the partition will not be deformed. This completely eliminates unexpected troubles such as contact between the partition part of the partition body and the impeller.

〔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 FIG. 1, reference numeral 1 indicates a casing shell of a centrifugal pump, and this casing shell 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 shell 1, and a suction boat 3 opens at the other end of the casing shell 1. This casing shell 1 is connected by a fixed flange 2 to a motor bracket (not shown) or the like.

A volute chamber A is formed in the circumferential direction at the center inside the casing shell 1, and the outer periphery of the volute chamber A is defined by an overhanging portion 1a. The projecting portion 1a is formed by bulging the outer circumferential wall of the casing shell 1 outward in the radial direction, and the projecting height H is as shown in FIGS. 3(a) to 3(d). The height of the volute chamber A gradually increases in the direction of fluid flow. .

An impeller 5 is provided inside the casing shell 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 shell 1.

The end wall 1b of the casing shell 1 on the suction side is curved into a mirror plate shape to increase rigidity, and the suction boat 3 is opened in the center of the end wall 1b. A peripheral edge IC defining this suction boat 3 is bent toward the impeller 5 and is formed into a substantially cylindrical shape.

A suction flange 10 formed by press as a separate member is connected to the suction boat 3 by welding. This suction flange 10 is formed into a double ring structure in which an inner circumferential wall 10b and an outer circumferential wall 10c are integrally formed with respect to a ring plate 10a, and the inner circumferential wall 10b is formed at the above-mentioned circumferential edge 1.
The outer circumferential wall 10c is fitted onto the inner periphery of the end wall 10c and is welded to the outer surface of the end wall 1b having the shape of a mirror plate. A suction port 11 connected to the suction boat 3 is opened in the center of the suction flange 10 .

A sealing surface 12 for connecting a companion flange (not shown) is formed on this suction flange 10, and a thick reinforcing flange 13 is fixed to the back side of this sealing surface 12. Four bolt holes 14 are drilled in the suction flange 10, and four female threaded holes are drilled in the reinforcement 7 flange 13 in alignment with the bolt holes 14, as is clear from FIG. 15 is screwed. A bolt (not shown) is inserted into this female threaded hole 15 from the direction of arrow Y.
A relief recess 17 is formed in the mirror plate-like end wall 1b of the casing shell 1 as a relief for receiving the tip of the bolt.

Further, a partition body 20 having a substantially S-shaped cross section is fixed to the inner surface of the shoulder portion 1d of the casing shell 1, and this partition body 20 integrally has a cylindrical partition portion 20a. A diffuser 20b that extends in a tapered shape toward the suction port 3 side is integrally provided in the partition portion 20a. The diameter of the suction side end of this diffuser 20b is approximately the same as the diameter of the suction boat 3, and furthermore, the diffuser 20b
A slight axial gap 21 is formed between the edge of b and the peripheral edge of the suction boat 3. A liner ring 22 having a substantially L-shaped cross section is press-fitted into the inner periphery of the partition 20a until the flange 22a abuts against the partition 20. The end portion 5a of the impeller 5 is loosely fitted. And pressure chamber A
and the suction chamber B are separated by a liner ring 22 of the partition portion 20a.

As shown in FIG. 2, plugs 23 and 24 are attached to the top and bottom of the casing shell 1, and the upper plug 23 is used for air venting, and the F plug 24 is used for draining water. These plugs 23, 24 are mounted in a flat part 25 of the shoulder 1d of the housing acid 1, which is partially formed flat. In this flat part 25, as shown in FIG.
Plugs 23, 24 are screwed through. An O-ring 28 is attached to the inner surface of the spacing ring 27, and when the plugs 23, 24 are tightened, the O-ring 28 deforms to prevent fluid leakage. In addition, a groove 2 extending in the longitudinal direction is provided on the outer periphery of the shaft of the plug 23, 24.
9 is formed so that air or drain can be removed without completely removing the plugs 23, 24, that is, even if they are slightly loosened.

Furthermore, as is clear from FIGS. 2 and 3, one end of the nozzle 30 is connected to the highest overhang part of the casing acid 1, a. A discharge flange 31 is connected to the other end of the nozzle 30, and a discharge port 32 is opened at the center of the discharge flange 3. The structure of the discharge flange 31 itself is the same as that of the connection flange 10, so a description thereof will be omitted.

Next, the operation of the funnel-wound pump 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 30, and is discharged from the discharge port 32 of the discharge flange 31.

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 end wall 1b of the casing acid 1, and 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 with can be reliably avoided. Furthermore, since an axial gap 21 is formed between the edge of the diffuser 20b and the peripheral edge of the suction boat 3, even if the suction flange 10 is tilted, the diffuser 2
The edge of 0b and the periphery of the suction boat 3 do not come into contact with each other, and this also reliably prevents the partition portion 20a of the partition body 20 from deforming.

In addition, the suction flange 10 is formed in a so-called double ring shape, and the inner circumferential wall 10b and outer circumferential wall 10e are each firmly fixed to the casing acid 1, so that the rigidity of the casing acid 1 is significantly increased and deformation It can be made into something with less.

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 end wall 1b of the casing acid 1 is curved outward in the shape of a mirror plate, the rigidity of the casing acid 1 is increased. Also, the edge of the diffuser 20b is a suction po! Since it extends close to the periphery of -3, it is also possible to reliably prevent the pump performance from deteriorating.

Furthermore, when removing air or drain, the plugs 23, 24 can be removed by loosening them slightly without having to completely remove them.

Furthermore, as is clear from Fig. 1, when the air is removed when starting the pump, loosening the upper plug 23 removes not only the air in the pressure chamber A but also the air in the cavity C. They can be removed at the same time. The air in this cavity C passes through the gap between the end wall 1b and the partition body 20, and further through the groove 29 on the outer circumference of the shaft of the plug 23, and exits to the outside. Incidentally, when stopping the pump and draining the drain, the same can be done by loosening the lower plug 24.

Further, FIGS. 4 and 5 show other embodiments.

According to this embodiment, a band-shaped support portion 38 extending toward the discharge flange 31 is integrally formed on the peripheral edge of the outer peripheral wall 10b of the suction flange 10, and an end portion 38a of the support portion 38 is bent into a substantially dogleg shape, and this end portion 38a is firmly fixed to the back surface of the discharge flange 10. Further, in order to reinforce the discharge flange 10, a band-shaped support member 39 is fixed to the fixed flange 2, and an end portion 39a of this support member 39 is bent into a substantially dogleg shape. is firmly fixed to the back surface of the discharge flange 10.

With this configuration, as described above, not only can the rigidity of the suction flange 10 be increased, but also the rigidity of the discharge flange 31 can be increased at the same time, and a pump casing with sufficient rigidity can be provided. can.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, the suction side end of the casing shell is curved into a mirror plate shape, and the suction flange is formed into a double ring shape having an inner circumferential wall and an outer circumferential wall. Since the inner circumferential wall is fixed to the peripheral edge of the suction boat and the outer circumferential wall is fixed to the mirror plate-like outer surface of the casing shell, the rigidity of the casing shell is increased and it can be made less deformable. In addition, a partition is provided inside the casing shell to separate the suction chamber and the pressure chamber, and a diffuser having an edge tapering toward the periphery of the suction port is integrally provided at the suction side end of the partition. extended to
Since an axial gap is formed between the edge of the diffuser and the periphery of the suction boat, even if an external force is applied to the suction flange, the external force will be transmitted to the fixed flange through the casing shell, and the partition body will be Even if the suction flange is tilted, the edge of the diffuser and the periphery of the suction port will not come into contact with each other, so the partition will not be deformed, and the partition will not be deformed. It is possible to completely eliminate unexpected troubles such as contact between the partition part and the impeller.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view showing one embodiment of a sheet metal centrifugal pump casing according to the present invention, FIG. 2 is a front view of the same, and FIG.
4 is a longitudinal sectional view showing another embodiment of the sheet metal centrifugal pump casing according to the present invention, and FIG.
The figure is also a front view. 1...Casing shell, 3...Suction boat, 5...
Impeller, 10... Suction flange, 10a... Ring plate, 10b... Inner peripheral wall, 10c... Outer peripheral wall, 20
... partition body, 20a ... partition part, 20b ... diffuser, 22 ... liner ring.

Claims (1)

[Claims] 1. A spiral pump casing in which a steel plate is deep-drawn using a press to form a casing shell having a suction port, and a suction flange is fixed to the suction port of the casing shell. The suction side end is curved into a mirror plate shape, and the suction flange is formed into a double ring shape having an inner peripheral wall and an outer peripheral wall, the inner peripheral wall is fixed to the peripheral edge of the suction port, and the outer peripheral wall is fixed to the peripheral edge of the suction port. A wall is fixed to the mirror plate-like outer surface of the casing shell, and a partition body for partitioning a suction chamber and a pressure chamber is arranged inside the casing shell, and a suction side end of the partition body is provided with a partition body for partitioning a suction chamber and a pressure chamber. Made of sheet metal, characterized in that a diffuser having an edge tapering toward the periphery is integrally installed, and an axial gap is formed between the edge of the diffuser and the periphery of the suction port. Whirlpool pump casing. 2. The sheet metal spiral pump casing according to claim 1, wherein a relief recess for receiving a tip of a flange fixing bolt is formed on the mirror plate-like outer surface of the casing shell. 3. A support portion extending toward the discharge flange side of the pump casing is integrally formed at the peripheral edge of the outer peripheral wall of the suction flange, and an end portion of the support portion is firmly fixed to the back surface of the discharge flange. The sheet metal centrifugal pump casing according to claim 1.