JPH0579838B2 - - Google Patents

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, which is designed to suppress deformation of the liner portion of the casing even when an external force is applied to the suction flange. Regarding the sheet metal centrifugal pump casing.

[Conventional technology]

In general, a spiral pump casing made of sheet metal is known, which is made by deep drawing a piece of stainless steel plate 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. There is.

This type of centrifugal pump casing tends to be weak in strength, and when an external force acts on the suction flange, there is a risk that this external force will be directly transmitted to the casing shell and deform the liner. When the liner section deforms, it hits the impeller, which causes problems such as noise and pump overload, and even causes unexpected situations such as the casing shell and the impeller coming into contact and damaging the impeller. It may lead to.

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 external force is applied, only a part of the casing shell is deformed by this free structure, and this deformation does not affect the partition body. .

Also, from another point of view, a reinforcing member is stretched between the suction flange and the casing shell to create a so-called rigid structure, so that the external force acting on the suction flange is directly transmitted to the casing shell, and the casing shell itself A method has been proposed in which it is absorbed by the body.

[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 shell is applied to the suction flange, the liner part of the casing shell will deform, causing the above-mentioned hit. There is a problem that occurs.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the conventional technology, and to provide a sheet metal that can completely suppress deformation of the liner portion of the casing even when an excessive external force is applied to the suction flange. Our purpose is to provide manufactured centrifugal pump casings.

[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 shell having a suction port, and a suction flange is fixed to the suction port of the casing shell. 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 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 shell, and a partition is provided inside the casing shell to separate the suction chamber and the pressure chamber, and the peripheral edge of the suction port is attached to the suction side end of the partition. It is characterized by integrally extending a diff user having an end edge tapering toward the suction port, and forming an axial gap between the end edge of the diff user and the periphery of the suction port. .

[Effect]

According to the present invention, the end of the suction side 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 peripheral wall and an outer peripheral wall, and the inner peripheral wall is formed as a double ring. Since it is fixed to the peripheral edge of the port and the outer peripheral wall is fixed to the mirror plate-like outer surface of the casing shell, the rigidity of the casing shell is high and it can be made less deformed. A partition is disposed to partition the suction chamber and the pressure chamber, and a diff user 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 differential user and the periphery of the suction port, even if an external force is applied to the suction flange, that external force will be transmitted to the fixed flange through the casing shell. Therefore, the partition will not be deformed, and even if the suction flange were to tilt, the edge of the differential user and the periphery of the suction port will not come into contact with each other, so the partition will not be deformed. Therefore, unexpected troubles such as those caused by contact between the partition part of the partition body and the impeller can be completely eliminated.

〔Example〕

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, one embodiment of a sheet metal centrifugal pump casing according to the present invention will be described 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 port 3 is opened 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 a circumferential direction in the center inside the casing shell 1, and the outer periphery of the volute chamber A is defined by an overhanging portion 1a. This overhanging portion 1a is formed by expanding the outer circumferential wall of the casing shell 1 outward in the radial direction, and the overhanging height H is as shown in FIGS. 3a to 3d. The height increases continuously along the circumferential direction (counterclockwise in the figure), so that 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 casing shell 1, and the impeller 5 is integrated with a boss 6.
This boss 6 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 port 3 is opened in the center of the end wall 1b. Peripheral portion 1c defining this suction port 3
is bent toward the impeller 5 side and formed into a substantially cylindrical shape.

A suction flange 10 formed by press as a separate member is connected to the suction port 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 the ring plate 10a, and the inner circumferential wall 10b is fitted and welded to the inner circumference of the circumferential edge portion 1c, and the outer circumferential wall 10c is fixed to the outer surface of the mirror plate-shaped end wall 1b by welding. A suction port 11 connected to the suction port 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 bored in the suction flange 10,
As is clear from FIG. 2, the reinforcing flange 13 is provided with four female threaded holes 15 in alignment with the bolt holes 14. A bolt (not shown) is screwed into this female threaded hole 15 from the direction of arrow Y, and a relief recess is provided in the end wall 1b of the mirror plate shape of the casing shell 1 as a relief for receiving the tip of the bolt. 17 is formed.

Moreover, on the inner surface of the casing shell 1 and the shoulder part 1d,
A partition body 20 having a substantially S-shaped cross section is fixed, and this partition body 20 has a cylindrical partition portion 20a.
The partition portion 20a has a differential user 2 extending in a tapered shape toward the suction port 3 side.
0b are integrally extended. The diameter of the suction side end of this differential user 20b is approximately the same as the diameter of the suction port 3, and the differential user 20b
A slight axial gap 21 is formed between the edge of b and the periphery of the suction port 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. End portion 5 of the impeller 5
A is loosely fitted. The 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, with the upper plug 23 used for air bleeding and the lower plug 24 used for draining. These plugs 23, 24 are mounted in a flat part 25 of the shoulder 1d of the casing shell 1, which is partially formed flat. In this flat portion 25, as shown in FIG. 23 and 24 are screwed in. An O-ring 2 is attached to the inner surface of this spacing ring 27.
8 is attached and the plugs 23 and 24 are tightened, the O-ring 28 is deformed to prevent fluid leakage. In addition, plugs 23, 2
A groove 29 extending in the longitudinal direction is formed on the outer periphery of the shaft of No. 4, so that air or drain can be removed without completely removing the plugs 23 and 24, that is, even when they are slightly loosened. There is.

Further, as is clear from FIGS. 2 and 3, one end of the nozzle 30 is connected to the highest overhanging portion 1a of the casing shell 1. 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 31. 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 centrifugal 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 port 3. This sucked fluid passes through the inside of the impeller 5, is given centrifugal force, and flows from its outer circumference to the volute chamber A.
released within. 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 shell 1, and does not directly reach the partition body 20. .
Therefore, due to the action of external force, the suction flange 1
Even if the deformation reaches 0, the partition portion 20a of the partition body 20
The liner ring 22 is not deformed, and contact between the liner ring 22 and the end portion 5a of the impeller 5 can be reliably avoided. Further, there is a gap in the axial direction between the edge of the differential user 20b and the periphery of the suction port 3.
21 is formed, the suction flange 10
Even if the differential user 20
The edge of b and the periphery of the suction port 3 do not come into contact with each other, and thereby the partition portion 20a of the partition body 20 can be reliably prevented from deforming.

Further, the suction flange 10 is formed in a so-called double ring shape, with an inner circumferential wall 10b and an outer circumferential wall 10b.
c are each firmly fixed to the casing shell 1, so that the rigidity of the casing shell 1 is significantly increased, and the casing shell 1 can be made less deformable.

Furthermore, according to this embodiment, the casing shell 1
Since a volute chamber A is formed in the center of the pump, the flow path area of which gradually increases in the circumferential direction, the pump performance is greatly improved. Also, the end wall 1 of the casing shell 1
Since b is formed by curving outward in the shape of a mirror plate, the rigidity of the casing shell 1 is increased. Furthermore, since the edge of the differential user 20b extends close to the periphery of the suction port 3, this also ensures that the pump performance is prevented from deteriorating.

Further, when removing air or drain, the plugs 23 and 24 can be removed by loosening them slightly without having to remove them completely.
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 space C escapes to the outside through the space between the end wall 1b and the partition 20, and further through the groove 29 on the outer circumference of the shaft of the plug 23. 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 this support portion 38 is formed.
is bent into a substantially dogleg shape, and this end portion 38a is firmly fixed to the back surface of the discharge flange 10. In order to reinforce the discharge flange 10, a belt-shaped support member 3 is attached to the fixed flange 2.
An end portion 39a of this supporting member 39 is bent into a substantially dogleg shape, and this end portion 39a is firmly secured 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 port and the outer circumferential wall is fixed to the mirror plate-like outer surface of the casing shell, the casing shell has high rigidity and is less likely to deform. In addition, a partition body that partitions the suction chamber and the pressure chamber is provided inside the casing shell, and a differential user having an edge that tapers toward the periphery of the suction port is integrated at the suction side end of the partition body. Since an axial gap is formed between the edge of the differential user and the periphery of the suction port, even if an external force is applied to the suction flange, that external force will be transmitted to the fixed flange through the casing shell. Therefore, the partition will not be deformed, and even if the suction flange were to tilt, the edge of the differential user and the periphery of the suction port will not come into contact with each other. Deformation does not occur, and unexpected troubles such as those caused by contact between the partition part of the partition body and the impeller can be completely eliminated.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view showing an embodiment of a sheet metal spiral pump casing according to the present invention, FIG. 2 is a front view, FIG. 3 is a cross-sectional view, and FIG. FIG. 5 is a longitudinal sectional view showing another embodiment of the pump casing, and is also a front view. 1...Casing shell, 3...Suction port, 5...
...Impeller, 10...Suction flange, 10a...
Ring plate, 10b... Inner peripheral wall, 10c... Outer peripheral wall, 20... Partition body, 20a... Partition part, 20b
...Deaf user, 22...Liner ring.

Claims (1)

[Scope of Claims] 1. A spiral pump casing in which a steel plate is deep-drawn by 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 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 mirror plate-like outer surface of the casing shell, and a partition body for partitioning a suction chamber and a pressure chamber is provided inside the casing shell, and a peripheral edge of the suction port is attached to the suction side end of the partition body. A sheet metal whirlpool, characterized in that a diff user having an end tapered toward the end is integrally extended, and an axial gap is formed between the end edge of the diff user and the periphery of the suction port. Volume 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 part extending toward the discharge flange side of the pump casing is integrally formed on the peripheral edge of the outer peripheral wall of the suction flange, and an end of the support part is firmly fixed to the back surface of the discharge flange. The sheet metal spiral pump casing according to claim 1.