JPH0361698A - Volute pump made of sheet metal - Google Patents

Abstract

PURPOSE:To restrain the liner of a casing from being deformed so as to enhance a discharge performance even if an excessive external force is exerted on a suction flange by forming the tip end of a cylindrical suction nozzle, which extends toward the suction port of a casing cell, in the mouth of an impeller. CONSTITUTION:A cylindrical suction nozzle 20 extending toward an impeller 5 is integrally formed at the circumferential edge of the suction port 11 of a suction flange 10. The tip end 20a of the nozzle 20 is loosely inserted at the circumferential edge thereof into the mouth 5a of the impeller 5, and a ring-type deflector 21 having a substantially L-shaped cross-section is secured at the peripheral portion to extend in a circumferential direction. An external force exerted on the suction flange 10 is transmitted to a stationary flange 2 through the flange support 1c of a casing cell 1, and is not transmitted directly to the suction nozzle 20. Accordingly, even if the suction flange 10 is deformed by the external force, the suction nozzle 20 cannot be deformed, thereby securely preventing the tip end 20a of the suction nozzle 20 from being brought into contact with the mouth 5a of the impeller 5.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a centrifugal pump made of sheet metal, and in particular, when an external force is applied to the suction flange, deformation of a part of the liner of the casing can be suppressed, and at the same time, , relates to a sheet metal centrifugal pump that can also improve the pump's discharge performance.

[Conventional technology]

In general, sheet metal centrifugal pumps are known in which a casing shell having a suction port is formed by deep drawing two stainless steel plates or the like using a press, and a suction flange is fixed to the suction port of the casing shell. .

This type of centrifugal pump tends to be weak in strength, and when 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 a portion of the liner to deform. When a part of the lychee deforms, it will hit the impeller, which will cause problems such as noise and pump overload, and even cause unexpected problems such as impeller damage due to contact between the casing acid and the impeller. This may lead to an incident.

Therefore, conventionally, a partition body is provided inside the casing shell to partition the suction chamber and the pressure chamber, and a liner ring is attached to the partition part of the partition body, and the liner ring extending outside the partition body is A so-called flexible structure is adopted for a part of the casing shell, and when the above external force is applied, this flexible structure deforms only a part of the casing shell to prevent this deformation from being directly transmitted to the casing acid. Therefore, a structure has been proposed in which the deformation does not extend to the partition portion of the partition body.

[Problem to be solved by the invention]

However, with the above configuration, the structure is complicated, and when connecting the suction pipe to the suction flange, the suction pipe itself must be supported against the foundation with another member. There is a troubling problem.

In addition, in the case where a partition is provided inside the casing shell and a liner ring is attached to the partition of the partition, excess material protrudes into the suction flow path, increasing suction resistance loss and causing pump damage. There is a problem that the ejection performance deteriorates.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned problems of the conventional technology, to provide a simple structure, and to suppress deformation of a part of the liner of the casing when an excessive external force is applied to the suction flange. It is an object of the present invention to provide a centrifugal pump made of a sheet metal which can improve the discharge performance of the pump at the same time.

[Means to solve the problem]

In order to achieve the above object, the present invention integrally forms a casing shell by deep-drawing a steel plate using a press, rotatably supports an impeller inside the casing shell, and a mouse of the impeller. In the sheet metal centrifugal pump, which faces the suction port of the casing shell, a cylindrical suction nozzle is extended to the suction port of the casing shell, and the tip of this suction nozzle is extended into the mouth of the impeller. It is characterized by:

[For production]

According to the present invention, the cylindrical suction nozzle is extended to the suction port of the casing shell, and the tip of this suction nozzle is extended into the mouth of the impeller, so that excessive external force is not applied to the suction flange. However, this external force passes through the casing shell and reaches the fixed flange side, and does not directly reach the suction nozzle. Therefore, the suction nozzle itself is unlikely to be deformed, and the tip and blades of the suction nozzle are Collisions with the car mouse are avoided. At the same time, since the tip of the suction nozzle extends into the mouth of the impeller, nothing extraneous protrudes into the suction flow path, and fluid suction resistance loss can be suppressed to a low level.

〔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 7 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 has a shoulder 1b that projects outward to increase the rigidity, and is formed into a substantially S-shaped cross section, and is further provided with a substantially cylindrical flange at the tip of the wall on the suction side. A support portion 1c is integrally formed. A suction flange IO formed by press as a separate member is connected to this flange support portion 1c, and this suction flange 10
A suction port 1 connected to the above-mentioned suction port 3 is opened in the center of the .

This suction flange 10 is formed with a sealing surface 12 for connecting a companion flange (not shown), and as is clear from FIG. A reinforcing flange 13 is fixed thereto. The suction flange 10 has four bolt holes 1.
As is clear from FIG. 2, four through holes 15 are bored in the reinforcing 7 flange 13 in alignment with the bolt holes 14.

Further, according to this embodiment, on the peripheral edge of the suction port 11 of the suction flange 10, extending toward the impeller 5 side,
A cylindrical suction nozzle 20 is integrally formed.

The suction nozzle 20 is formed to become thicker toward the impeller 5 side. The periphery of the tip 20a of the suction nozzle 20 is loosely fitted into the mouth 5a of the impeller 5, and at the loosely fitted intersection, the peripheries of both are overlapped with an appropriate width in the axial direction. . Furthermore, a ring-shaped protrusion or deflector 21 extending in the circumferential direction and having a substantially L-shaped cross section is fixed to the outer peripheral portion of the suction nozzle 20 .

Further, as is clear from FIG. 2, one end of a discharge nozzle 25 is connected to the highest position 23 of the overhanging portion 1a of the casing acid 1, and a discharge flange 26 is connected to the other end of this discharge nozzle 25. ing. This discharge flange 26 is firmly supported by the fixed flange 2 by a band-shaped support member 27, and a discharge port 28 is opened in the center of the discharge flange 26. The structure of the discharge flange 26 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 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 through the suction nozzle 20.

This sucked fluid passes through the inside of the impeller 5, is subjected to centrifugal force, and is discharged into the volute chamber A from its outer periphery. The discharged fluid moves in the circumferential direction (counterclockwise in FIG. 2) within the volute chamber A, passes through the discharge nozzle 25, and is discharged from the discharge port 28 of the discharge flange 26.

According to this embodiment, the inner surface of the suction nozzle 20 is formed smoothly and no extra protrusions protrude therefrom, so that the fluid flowing through the suction nozzle 20 is
The fluid flows smoothly into the impeller 5, and therefore, the suction resistance loss of the fluid can be suppressed to a low level.

In addition, a part of the fluid that passes through the inside of the impeller 5, is given a centrifugal force, and is released into the volute chamber A from its outer periphery is in the annular shape between the flange support part 1c and the suction nozzle 20. It flows back into the flow path B. However, since the deflector 21 is disposed there, the fluid flowing backward is injected into the impeller 5 through the gap between the tip 20a of the suction nozzle 20 and the mouth 5a, as shown by the arrow Y. The volute is discharged into the volute chamber A from its outer periphery after being subjected to centrifugal force. According to this, the so-called annular flow path B
Inward fluid leakage is reduced, and the pump's discharge performance can be improved by about 5%.

Furthermore, 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 flange support part IC of the casing acid 1,
It does not reach the suction nozzle 20 directly. therefore,
Even if the suction flange 10 is deformed due to the action of an external force, the suction nozzle 20 is hardly deformed, and contact between the tip 20a of the suction nozzle 20 and the mouth 5a of the impeller 5 can be reliably avoided.

In addition, a volute chamber A whose flow path area gradually increases in the circumferential direction is formed in the center of the casing acid 1, so the pump performance is extremely improved. Since the casing acid 1 is made to protrude outward and has a substantially S-shaped cross section, the rigidity of the casing acid 1 is greatly increased.

FIG. 3 shows another embodiment. Above suction nozzle 2
A protrusion 30 is integrally formed in the middle of the outer peripheral wall of 0,
This protrusion 30 extends in the circumferential direction and is formed to bulge outward in the radial direction.

According to this, the protrusion 30 is connected to the deflector 21 (the first
Since the pump functions in the same manner as the pump shown in FIG. 1, fluid leakage into the so-called annular flow path B is reduced, and the pump's discharge performance can be improved compared to the conventional pump.

Moreover, FIG. 4 shows another embodiment. According to this, a liner ring 32 having a substantially linear cross section is press-fitted onto the outer periphery of the tip 20a of the suction nozzle 20, and the outer periphery of the liner ring 32 is loosely fitted into the mouth 5a of the impeller 5. has been done. This liner ring 32 is
It constitutes a so-called partition portion that partitions the annular flow path B and the inside of the mouth 5a of the impeller 5. According to this, fluid leakage from the partition portion is significantly suppressed.

FIGS. 5 and 6 each show other embodiments. According to FIG. 5, the liner ring 3 has an L-shaped cross section.
3 is press-fitted into the outer periphery of the tip 20a of the suction nozzle 20, and according to FIG.
is press-fitted into the outer periphery of the In this way, fluid leakage from the so-called partitions is significantly suppressed, similar to what is shown in FIG.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, a casing shell is integrally formed by deep drawing a steel plate using a press, and an impeller is rotatably supported inside the casing shell. In a sheet metal centrifugal pump with a mouth facing the suction port of the casing shell, a cylindrical suction nozzle is extended to the suction port of the casing shell, and the tip of this suction nozzle is extended into the mouth of the impeller. Therefore, even if an excessive external force is applied to the suction flange, the suction nozzle is unlikely to be deformed, and therefore, it is possible to sufficiently avoid the tip of the suction nozzle and the mouth of the impeller, and at the same time, Since no extra material protrudes into the suction flow path, suction resistance loss of fluid can be suppressed to a low level, and the discharge performance of the pump can be improved compared to conventional pumps.

[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.
The figure is a longitudinal sectional view showing another embodiment, and FIGS. 4 to 6 are longitudinal sectional views showing other embodiments. 1...Casing acid, 3...Suction port, 5...
Impeller, 10... Suction flange, 20... Suction nozzle, 20 a-... Tip, 21.30-... Projection,
32. 33°34...liner ring.

Claims (1)

[Claims] 1. A casing shell is integrally formed by deep drawing a steel plate using a press, and an impeller is rotatably supported inside the casing shell, and the mouth of the impeller is attached to the casing shell. In the sheet metal centrifugal pump facing the suction port of the casing shell, a cylindrical suction nozzle is extended to the suction port of the casing shell, and the tip of the suction nozzle is extended into the mouth of the impeller. A sheet metal whirlpool pump featuring: 2. The sheet metal centrifugal pump according to claim 1, wherein a liner ring is attached to the tip of the suction nozzle extending into the mouth of the impeller. 3. The sheet metal centrifugal pump according to claim 1, wherein a protrusion extending in the circumferential direction is provided on the outer periphery of the suction nozzle.