JPH0610890A - Sheet metal-made pump casing and full peripheral flow type pump provided with thi pump casing - Google Patents

Abstract

PURPOSE:To provide a sheet metal-made pump casing with no necessity for enlarging a plate thickness more than necessary and no necessity for providing a reinforcing member for reinforcing the pump casing by providing the proper plate thickness relating to piping external force and internal pressure while deformation can be suppressed in a liner part of the pump casing. CONSTITUTION:In a constitution, a sheet metal-made pump casing comprises a sheet metal-made outer casing 2 having a suction nozzle 3, inner casing 10 of at least one part made of sheet metal provided in the outer casing 2 in a condition separated therefrom to house an impeller 15 in the inside of the casing 10 and a seal member 14 interposed in a clearance between the inner and outer casings 10, 2 to consist of elastic material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet metal pump casing and an all-circumferential flow type pump provided with the pump casing, and more particularly to a pump casing manufactured by press forming a steel plate such as stainless steel and the pump casing. All-round pump.

[0002]

2. Description of the Related Art Conventionally, a pump casing has been manufactured by deep-drawing a single steel plate such as stainless steel by a press. The suction flange and the discharge flange are fixed to the press-molded pump casing by welding or the like. Such a pump casing is subjected to an internal pressure generated by the pump itself and an external force such as an external force of a pipe to cause some deformation. This deformation must be small enough not to cause contact between the casing and the impeller. Therefore, the press pump casing has a strength function that supports external loads such as piping and internal pressure.
It requires two functions of rigidity to secure the clearance between the sliding parts of the rotor (between the liner ring and the impeller).

However, from the viewpoint that the press-made pump casing originally has a flexible structure against a load, it is difficult for the pump casing itself to satisfy both the strength function and the rigidity function at the same time. Therefore, in order to ensure rigidity, the conventional press pump casing has a plate thickness thicker than necessary strength against internal pressure, or
A reinforcing member having a complicated shape is provided between the suction flange and the pump casing to reinforce the suction flange and the pump casing. West German publication (DE OS) 3rd
No. 517828 shows a conventional example in which a reinforcing member is provided, and has a complicated shape called a box girder so as to surround the suction nozzle 53 between the pump casing 51 and the suction flange 52 as shown in FIG. A reinforcing member 54 is provided. In this way, by increasing the plate thickness or by accommodating the reinforcing member, the liner ring is accommodated, or the liner part of the pump casing that itself functions as the liner ring is prevented from being deformed, and the clearance of the rotary sliding part is prevented. We are securing.

[0004]

In the conventional press pump casing, as described above, the rigidity of the pump casing is ensured in order to prevent the deformation of the liner portion of the pump casing. Therefore, the suction flange and the pump casing must be reinforced by making the plate thickness thicker than necessary for the internal pressure or providing a reinforcing member having a complicated shape. Therefore, there is a problem that press forming becomes difficult due to an increase in plate thickness, and the manufacturing cost is increased because the reinforcing member having a complicated shape is provided.

The present invention has been made in view of the above circumstances, and an object of the present invention is to prevent deformation of the liner portion of the pump casing and to have a proper plate thickness against external force and internal pressure of the pipe. To provide a sheet metal pump casing that does not need to be thicker than necessary and that does not need to be provided with a reinforcing member for reinforcing the pump casing, and an all-circumferential flow type pump including the pump casing. is there.

[0006]

In order to achieve the above object, the first aspect of the sheet metal pump casing of the present invention is a sheet metal outer casing having a suction nozzle, and the outer casing is separated from each other. An inner casing, at least a part of which is provided in the outer casing in a state where the impeller is housed therein, and which is made of sheet metal; and a seal member made of an elastic material interposed in a gap between the inner casing and the outer casing. It is characterized by having.

A second aspect of the sheet metal pump casing of the present invention is a sheet metal outer casing having a suction nozzle,
An inner casing provided in the outer casing and containing an impeller therein, and a handling liquid provided in the inner casing or the outer casing and pressurized by the impeller are prevented from leaking to the suction portion of the impeller. To this end, a seal member made of an elastic material that seals between the inner casing and the outer casing is provided.

The first aspect of the full-circulation pump of the present invention is
A full-circumferential flow type pump in which an annular flow path is formed between a pump casing and an outer peripheral portion of a motor provided in the pump casing, and a suction side casing made of sheet metal having a suction nozzle, and the suction side casing. An inner casing that is provided inside and that houses the impeller, and an elastic material that seals between the inner casing and the suction side casing in order to prevent the handling liquid pressurized by the impeller from leaking to the suction part of the impeller And a seal member made of, wherein the inner casing is supported by the motor.

The second aspect of the full-circulation pump of the present invention is
A full-circumferential flow type pump in which an annular flow path is formed between a pump casing and an outer peripheral portion of a motor provided in the pump casing, and a suction side casing made of sheet metal having a suction nozzle, and the suction side casing. A casing outer cylinder made of sheet metal that is connected to the outer peripheral side of the motor and an inner casing that houses an impeller inside the suction side casing, and a handling liquid that is pressurized by the impeller. In order to prevent leakage to the suction part of the impeller, a seal member made of an elastic material that seals between the inner casing and the suction side casing is provided, and the motor is supported by the casing outer cylinder. Is.

A third aspect of the full-circulation pump of the present invention is
A full-circumferential flow type pump in which an annular flow path is formed between a pump casing and an outer peripheral portion of a motor provided in the pump casing, and a suction side casing made of sheet metal having a suction nozzle, and the suction side casing. A casing outer cylinder made of sheet metal that is connected to the outer peripheral side of the motor and an inner casing that houses an impeller inside the suction side casing, and a handling liquid that is pressurized by the impeller. In order to prevent leakage to the suction part of the impeller, a seal member made of an elastic material that seals between the inner casing and the suction side casing is provided, and the suction side casing and the casing outer cylinder are respectively provided at the outer peripheral portions of the end portions. It is characterized in that it has a flange portion extending outwardly and is integrally connected by being sandwiched by another member.

[0011]

According to the first aspect of the sheet metal pump casing of the present invention having the above-described structure, the outer casing and the inner casing are separated from each other and are connected to each other via the seal member made of an elastic material. Therefore, even if the outer casing is deformed by an external force of the pipe or the like, the deformation is absorbed by the elastic material and is not transmitted to the inner casing. Therefore, since it is not necessary to give rigidity to the outer casing, it is not necessary to increase the plate thickness of the outer casing more than necessary, and it is not necessary to reinforce the outer casing with a reinforcing member. On the other hand, since the inner casing constitutes the liner portion, it is easy to secure the clearance of the liner portion, and since the inner casing is released from the load such as the external force of the pipe, the plate thickness can be reduced and the press molding is facilitated. In addition, it becomes easier to secure the accuracy of press molding.

According to the second aspect of the sheet metal pump casing of the present invention, a seal member made of an elastic material integrally provided in the inner casing or the outer casing is provided, and the outer casing is deformed by the elastic material. Be absorbed.

According to the first aspect of the full-circulation pump of the present invention, since the inner casing is supported by the motor in a state of being separated from the suction side casing, vibration and noise of the motor are mediated by the inner casing. Will not be transmitted to the outside. Therefore, it can be said that the structure is suitable for preventing vibration and noise of the motor.

According to the second aspect of the omnidirectional pump of the present invention, since the motor is housed in the casing outer casing made of sheet metal, an external force such as an impact force is applied to the casing outer casing. Is also absorbed by the outer casing of the sheet metal casing, making it difficult for external force to be transmitted to the motor. Further, since only the casing outer cylinder and the motor are connected, even if the casing outer cylinder and the suction side casing are deformed by an external force or the like, there is no fear of the deformation being transmitted to the liner portion.

Further, according to the third aspect of the omnidirectional flow pump of the present invention, even if the vibration of the motor is transmitted to the casing outer casing, the casing outer casing and the suction side casing are separate members such as flanges. The vibration of the motor is less likely to be transmitted to the suction side casing and further to the piping because the seal member is interposed between the two. Therefore, it is possible to prevent the resonance of the piping system due to the propagation of the vibration of the motor.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a sheet metal pump casing and an all-circumferential type pump provided with the pump casing according to the present invention will be described below with reference to FIGS. FIG. 1 is a sectional view showing an all-in-flow type in-line pump provided with a sheet metal pump casing of the present invention. The all-circumferential flow type in-line pump shown in this embodiment includes a suction side casing 1, a discharge side casing 5, and an outer cylinder 9 connecting the suction side casing 1 and the discharge side casing 5. The suction side casing 1 and the discharge side casings 1 and 5 are formed by deep drawing a steel plate such as stainless steel by pressing. The suction-side casing 1, the outer cylinder 9, and the discharge-side casing 5 are provided with flange portions 1a, 9a, 9b, and 5a that extend outward, respectively, on the outer peripheral portions of the end portions on the opening side. Then, between the suction side casing 1 and the outer cylinder 9, the flange portions 1a, 9a that are adjacent to each other via the seal member 8 are sandwiched by the flanges 20A, 20B made of cast iron or the like and tightened by the bolts 37. , Connected together. Further, the discharge-side casing 5 and the outer cylinder 9 similarly have the flange portions 5 a, which are adjacent to each other with the seal member 8 interposed therebetween.
9b is clamped by flanges 21A and 21B made of cast iron or the like, and is fastened by a bolt 37 to be integrally connected. The seal member 8
Is formed of an elastic material such as rubber.

Suction side casing 1, discharge side casing 5
A pump casing made of sheet metal is configured with the outer cylinder 9 and
A canned motor 22 is arranged in the pump casing. Since the canned motor 22 is a general canned motor, its details are not shown in FIG. A suction flange 31 and a discharge flange 32 are fixed to the suction side casing 1 and the discharge side casing 5, respectively.

The suction side casing 1 comprises a frustoconical body 2 and a cylindrical suction nozzle 3 extending from the body 2 to the suction side. Similarly, the discharge-side casing 5 also includes a main body portion 6 and a discharge nozzle 7 extending from the main body portion 6 to the discharge side.

On the other hand, an inner casing 10 is provided inside the suction side casing 1. The inner casing 1
0 is formed by deep drawing a steel plate such as stainless steel by pressing. The inner casing 10 is composed of a container-shaped main body portion 11 and a cylindrical suction side portion 12 extending from the main body portion 11 to the suction side. A guide device 13 that constitutes a guide vane or volute is installed inside the main body 11 of the inner casing 10. The guide device 13 has a spigot fitting portion, and the spigot fitting portion is fitted to the motor frame of the canned motor 22. The motor frame of the canned motor 22 has a high rigidity, and the guide device 13 is supported by the motor frame. As a result, the inner casing 1
0 is supported by the motor frame of the canned motor 22 having high rigidity. One end of the suction side portion 12 of the inner casing 10 extends to the vicinity of the suction nozzle 3. A seal member 14 made of an elastic material is interposed in a gap between the end of the suction side portion 12 of the inner casing 10 and the suction nozzle 3 of the suction side casing 1. The seal member 14 allows the suction side ( The low pressure side) and the discharge side (high pressure side) are sealed.

An impeller 15 is housed inside the inner casing 10. The impeller 15 is a canned motor 22.
Is connected to and supported by the main shaft 16. A swirl prevention plate 18 is fixed inside the suction side portion 12 of the inner casing 10. The turning prevention plate 18 has a substantially U-shaped cross section as shown in FIG. 2, and is fixed to the suction side portion 12 by welding or the like at the outer end portion. The rear end portion of the suction side portion 12 of the inner casing 10 constitutes a liner portion L, and the impeller 1
A slight clearance is formed between the suction-side end edge portion 15a of 5 and the liner portion L.

The operation of the inline pump will be briefly described. The fluid sucked from the suction nozzle 3 is introduced into the impeller 15 through the suction side portion 12 of the inner casing 10. The fluid discharged from the rotating impeller 15 has its flow direction changed from the radial direction to the axial direction via the guide device 13, and then flows into the flow passage 45 formed between the outer cylinder 9 and the canned motor 22. Then, it flows into the discharge side casing 5 through the flow path 45. Then, the fluid is discharged from the discharge nozzle 7 formed integrally with the discharge side casing 5.

In this embodiment, the casing is divided into the suction side casing 1 and the inner casing 10, and the divided portion where a pressure difference between suction and discharge is generated is sealed by a seal member 14 made of an elastic material, and at the same time, this seal is formed. Since the deformation of the suction side casing 1 can be absorbed by the member 14, the deformation of the suction side casing 1 is not transmitted to the inner casing 10. Therefore, the inner casing 10 is not deformed, the clearance of the rotor sliding portion between the inner casing 10 forming the liner portion L and the impeller 15 can be secured, and the inner casing 10 contacts the impeller 15. Never.

Further, in this embodiment, since the inner casing 10 is supported by the canned motor 22 in a state of being separated from the suction side casing 1, the vibration and noise of the motor are transmitted to the outside through the inner casing 10. Never.
Therefore, it can be said that the structure is suitable for preventing vibration and noise of the motor.

Next, another embodiment of the present invention will be described with reference to FIG. FIG. 3 is a sectional view showing an all-circumferential type in-line pump of the present invention. In FIG. 3, components having the same functions and functions as those of the components in FIG. The all-circumferential flow type in-line pump shown in this embodiment includes a suction side casing 1, a discharge side casing 5, and an outer cylinder 9 connecting the suction side casing 1 and the discharge side casing 5. Suction side casing 1, outer cylinder 9
The discharge-side casing 5 has flange portions 1a, 9a, 9 extending outwardly on the outer peripheral portions of the end portions on the opening side, respectively.
b, 5a. The suction-side casing 1 and the outer cylinder 9 are adjacent to each other with the seal member 8 in between.
a and 9a are clamped by flanges 20A and 20B made of casting such as cast iron, and bolts 37a and nuts 37b are provided.
They are connected together by being tightened by. Further, similarly to the discharge side casing 5 and the outer cylinder 9, the flange portions 5a and 9b adjacent to each other via the seal member 8 are sandwiched by the flanges 21A and 21B made of cast iron or the like, and the bolt 37a and the nut 37b. They are connected together by being tightened by. Then, the suction side casing 1, the discharge side casing 5, and the outer cylinder 9
And form a pump casing made of sheet metal, and a canned motor 22 is arranged in the pump casing.

The suction side casing 1 is provided with a substantially cylindrical container-shaped main body 2 and an annular suction nozzle 3 which is joined to the main body 2 and extends on the suction side. Similarly to the suction side casing 1, the discharge side casing 5 also includes a substantially cylindrical container-shaped main body portion 6 and an annular discharge nozzle 7 joined to the main body portion 6 and extended to the discharge side. .

On the other hand, an inner casing 10 is provided inside the suction side casing 1.
Is a partition plate 11a made of sheet metal on the suction side, and this partition plate 11a
And a guide device 12a made of a resin material or the like that constitutes a guide vane or a volute. The guide device 12a has a spigot fitting portion, and the spigot fitting portion is fitted to the frame side plate 25 of the canned motor 22. The frame side plate 25 of the canned motor 22 has high rigidity, and the guide device 12a is supported by the motor frame side plate 25. As a result, the inner casing 10 has the frame side plate of the canned motor 22 having high rigidity. 25 will be supported. A seal member 14 is interposed in the gap between the partition plate 11a of the inner casing 10 and the suction side casing 1, and the suction side (low pressure side) and the discharge side (high pressure side) are sealed by the seal member 14. Has been done.

An impeller 15 is housed inside the inner casing 10. The impeller 15 is a canned motor 22.
Is fixed and supported by the main shaft 16 of the. Inner casing 1
A liner ring 19 is arranged at the inner end of the partition plate 11a of 0, and a slight clearance is formed between the liner ring 19 and the end edge portion 15a of the impeller 15.

A suction flange 31 and a discharge flange 32 are fixed to the annular suction nozzle 3 and discharge nozzle 7, respectively. That is, the suction nozzle 3 and the discharge nozzle 7 are made of the same material as the casing body, such as stainless steel, and have male screw portions 3c and 7c on the outer peripheral portion, and the front end surface is a sealing surface with a mating flange (not shown). 3s,
It has become 7s. On the other hand, the suction flange 31 and the discharge flange 32 are made of a material different from that of the casing body, for example, cast iron (FC) or the like, and have internal thread portions 31a and 32a at their inner ends, respectively. , 3
It is screwed and fixed to the suction nozzle 3 and the discharge nozzle 7 by 2a.

On the other hand, the motor frame 23 of the canned motor 22 has a substantially cylindrical frame outer case 24, and frame side plates 2 provided on both side openings of the frame outer case 24.
5, 26. The outer frame 24 is
A plurality of ribs 24a are radially formed on the outer peripheral surface thereof. The plurality of ribs 24a are formed integrally with the outer frame 24 of the motor frame by press molding, and the outer surfaces of these ribs 24a are fitted to the inner peripheral surface of the outer cylinder 9 of the pump casing and the fitting is performed. In the part, both are joined and integrated by spot welding or the like.

A lead wire outlet 24b is formed in one of the ribs 24a.
A lead wire of the motor is taken out from b, and the lead wire is taken out to a terminal box 38 fixed to the outer cylinder 9 through an opening 9c formed in the outer cylinder 9.

Outer frame 2 of the canned motor 22
A stator 27 and a rotor 28 are arranged in the unit 4. The rotor 28 is supported by the main shaft 16, and a cylindrical can 29 is fitted inside the stator 27. Further, a bearing housing 31 is detachably provided on the frame side plate 25 via an elastic body 30, and a radial bearing 32 for rotatably supporting a shaft sleeve 33 fitted to the main shaft 16 is held in the bearing housing 31. ing.

A bearing housing 35 is removably provided on the frame side plate 26 via an elastic body 34. The bearing housing 35 holds a radial bearing 36 and a fixed thrust metal 37, respectively. Cage,
The radial bearing 36 is the shaft sleeve 3 fitted to the main shaft 16.
It is designed to support 8 in rotation. On the other hand, a thrust disc 39 is fixed to the end of the main shaft 16 on the discharge side, and the thrust disc 39 is provided with a rotating thrust metal 40 that is in sliding contact with the fixed thrust metal 37. The bearing housing 35 is held by a holding plate 42 fixed to the discharge side casing 5.

The operation of the in-line pump will be briefly described. The fluid sucked from the suction nozzle 3 is the impeller 1.
Guided within 5. The fluid discharged from the rotating impeller 15 has its flow direction changed from the radial direction to the axial direction through the guide device 12a of the inner casing 10, and then the outer cylinder 9 and the motor frame outer body 23 of the canned motor 22 are separated from each other. It flows into the flow passage 45 formed between them, and flows into the discharge-side casing 5 through the flow passage 45. After that, the fluid is discharged from the discharge nozzle 7 provided in the discharge side casing 5.

Also in this embodiment, as in the embodiment shown in FIG. 1, the casing is divided into the suction side casing 1 and the inner casing 10, and the dividing portion where a differential pressure between suction and discharge is generated is
While sealing with the sealing member 14 made of an elastic material,
Since the deformation of the suction side casing 1 can be absorbed by the seal member 14, the deformation of the suction side casing 1 is not transmitted to the inner casing 10. Therefore, the inner casing 10 does not deform, the clearance of the rotor sliding portion between the liner ring 19 and the impeller 15 can be secured, and the liner ring 19 does not contact the impeller 15. Further, vibration and noise of the canned motor 22 are not transmitted to the outside through the inner casing 10.

Further, according to this embodiment, since the motor 22 is housed in the casing outer casing 9 made of sheet metal, even if an external force such as an impact force is applied to the casing outer casing 9, the casing outer casing 9 made of sheet metal. The external force is not easily transmitted to the motor 22. Since only the casing outer cylinder 9 and the motor 22 are connected via the ribs 24, even if the casing outer cylinder 9 and the suction side casing 1 are deformed by an external force or the like, this deformation causes the liner ring 19 to deform. There is no fear of being transmitted. Therefore, the clearance of the sliding portion of the rotating body can be secured.

Further, according to this embodiment, even if the vibration of the motor 22 is transmitted to the casing outer casing 9, the casing outer casing 9 and the suction side casing 1 are fixed by the flanges 20A and 20B which are separate members. And the seal member 8 is interposed between the two, the motor 22
Is transmitted to the suction side casing 1 and is less likely to be transmitted to the piping system. Therefore, it is possible to prevent the resonance of the piping system due to the propagation of the vibration of the motor.

Next, still another embodiment of the present invention will be described with reference to FIG. FIG. 4 is a cross-sectional view showing the all-circumferential flow type in-line pump of the present invention. 4, constituent elements having the same functions and functions as those of the constituent elements of FIG. 1 are designated by the same reference numerals and the description thereof will be omitted. The inner casing 10 in the all-circumferential flow type in-line pump shown in this embodiment has a partition wall 11c.
And a guide device 12d which is connected to the partition wall 11c and is made of a resin material or the like that constitutes a guide vane or a volute. The partition wall 11c is composed of a reinforcing material 11d forming a core material and an elastic material 11e molded into the reinforcing material 11d. The handling liquid whose pressure is increased by the elastic material is sucked by the impeller 15 of the impeller 15. A seal member that seals between the suction-side casing 1 and the inner casing 10 is provided to prevent the leakage. FIG. 5 is a sectional view showing still another embodiment. 5, constituent elements having the same operations and functions as those of the constituent elements of FIG. 1 are designated by the same reference numerals and the description thereof will be omitted. In this embodiment, the inner casing 10 is composed of a partition plate 11a and a guide device 12a as in the embodiment of FIG.
A seal member 14a made of an elastic material is formed on the inner surface of the suction side casing 1 by adhesion or molding. The seal member 14 a prevents the handling liquid whose pressure is increased by the impeller 15 from leaking to the suction portion of the impeller 15.

[0038]

As described above, according to the present invention,
The casing is divided into an outer casing and an inner casing,
Since the seal member made of an elastic material is interposed between the outer casing and the inner casing, even if the outer casing is deformed by an external force of the pipe or the like, the deformation is absorbed by the elastic material and is not transmitted to the inner casing. Further, since the internal pressure load applied to the inner casing is small (only the suction side portion), the deformation of the inner casing itself is small. Therefore, the outer casing only needs to have an appropriate plate thickness against the load such as the pipe external force and the internal pressure, and it is not necessary to increase the plate thickness more than necessary to secure the rigidity. No need to reinforce. Therefore, press molding becomes easy, and a pump casing with high productivity can be obtained. Moreover, since it is not necessary to provide a reinforcing member to the casing, it is possible to reduce the cost by reducing the number of parts. Further, the outer casing can have a simple shape that is not influenced by the guide device, and processing accuracy such as ensuring concentricity is unnecessary.

Further, since the inner casing constitutes the liner portion, it is easy to secure the clearance of the liner portion, and the inner casing is released from the load such as the external force of the pipe, so that the plate thickness can be reduced and the press molding can be performed. And the accuracy of press molding can be easily ensured. Moreover, it is possible to apply a material such as plastic to the inner casing.

Further, since at least a part of the inner casing is made of a press, vibration and noise are generated due to pulsation of the fluid and the like, but since this can be absorbed by the elastic material,
Vibration and noise will not be transmitted to the outer casing.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a sheet metal pump casing and an all-circumferential flow type pump including the pump casing according to the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a cross-sectional view showing another embodiment of a sheet metal pump casing and an all-circumferential flow type pump including the pump casing according to the present invention.

FIG. 4 is a cross-sectional view showing still another embodiment of the sheet metal pump casing and the all-circumferential flow type pump including the pump casing according to the present invention.

FIG. 5 is a cross-sectional view showing still another embodiment of a sheet metal pump casing and an all-circumferential flow type pump including the pump casing according to the present invention.

FIG. 6 is a sectional view showing an example of a conventional sheet metal pump casing.

[Explanation of symbols]

 1 Suction Side Casing 3 Suction Nozzle 5 Discharge Side Casing 7 Discharge Nozzle 8 Sealing Member 9 Outer Cylinder 10 Inner Casing 12a, 12d, 13 Guide Device 14 Sealing Member 15 Impeller 16 Spindle 19 Liner Ring 22 Canned Motor 23 Motor Frame 24 Outside Frame 45 channels

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshio Miyake 4-2-1 Motofujisawa, Fujisawa City, Kanagawa Prefecture EBARA Research Institute

Claims (5)

[Claims] 1. An outer casing made of sheet metal having a suction nozzle, and an inner casing made of sheet metal at least a part of which is provided inside the outer casing in a state of being separated from the outer casing and in which an impeller is housed. A sheet metal pump casing, comprising: a seal member made of an elastic material interposed in a gap between the inner casing and the outer casing. 2. An outer casing made of sheet metal having a suction nozzle, an inner casing provided in the outer casing and accommodating an impeller therein, and pressure boosted by an impeller provided in the inner casing or the outer casing. A sheet metal pump casing, comprising: a seal member made of an elastic material that seals between the inner casing and the outer casing in order to prevent the treated liquid from leaking into the suction portion of the impeller. 3. An all-circumferential flow type pump in which an annular flow path is formed between a pump casing and an outer peripheral portion of a motor provided in the pump casing, and a suction side casing made of sheet metal having a suction nozzle. , An inner casing provided in the suction side casing and containing an impeller therein, and a space between the inner casing and the suction side casing for preventing the handling liquid pressurized by the impeller from leaking to the suction part of the impeller. A sealing member made of an elastic material for sealing
An all-circumferential flow type pump, wherein the inner casing is supported by the motor. 4. An all-circumferential flow type pump in which an annular flow path is formed between a pump casing and an outer peripheral portion of a motor provided in the pump casing, and a suction side casing made of a metal plate having a suction nozzle. A sheet metal casing outer cylinder connected to the suction side casing and provided on the outer peripheral side of the motor; an inner casing provided in the suction side casing and containing an impeller therein; And a sealing member made of an elastic material that seals between the inner casing and the suction side casing in order to prevent the treated liquid from leaking to the suction part of the impeller, and the motor is supported by the casing outer cylinder. A full-circulation pump. 5. An all-circumferential flow type pump having an annular flow path formed between a pump casing and an outer peripheral portion of a motor provided in the pump casing, and a suction-side casing made of sheet metal and having a suction nozzle. A sheet metal casing outer cylinder connected to the suction side casing and provided on the outer peripheral side of the motor; an inner casing provided in the suction side casing and containing an impeller therein; In order to prevent the treated liquid that has been handled from leaking to the suction part of the impeller, a sealing member made of an elastic material that seals between the inner casing and the suction side casing is provided, and the suction side casing and the casing outer cylinder are respectively end portions. An all-circumferential-type pump having a flange part extending outwardly on the outer periphery of the part and being integrally connected by being clamped by another member. Pu.