JP2863756B2 - Sheet metal pump casing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pump casing made of sheet metal, and more particularly to a pump casing manufactured by press-forming a steel plate such as stainless steel.

[0002]

2. Description of the Related Art Conventionally, a pump casing has been manufactured by deep drawing a single stainless steel plate or the like by a press. Then, the suction flange and the discharge flange are fixed to the press-formed pump casing by welding or the like. External force such as pipe external force acts on the pump casing together with the internal pressure generated by the pump itself,
Some deformation occurs. This deformation must be kept small enough not to cause contact between the casing and the impeller. Therefore, the pump casing made of press
Strength function to support loads such as pipe external force and internal pressure. Two functions are required, a rigidity function to secure clearance between the rotating body sliding part (between the liner ring and the impeller).

[0003] However, from the viewpoint that a pump casing made of a press originally has a flexible structure against a load, it is difficult to simultaneously satisfy the strength function and the rigidity function with a single pump casing. Therefore, the conventional press-made pump casing, in order to ensure rigidity, to increase the plate thickness more than the strength required for 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 Open Gazette (DE OS) No. 3
No. 517828 shows a conventional example in which a reinforcing member is provided. As shown in FIG. 5, a complicated shape called a box girder is formed so as to surround a suction nozzle 53 between a pump casing 51 and a suction flange 52. The reinforcing member 54 is provided. In this way, the plate thickness is increased, or the liner ring is accommodated by the reinforcing member, or the liner portion of the pump casing which itself functions as a liner ring is prevented from being deformed, and the clearance of the rotary sliding portion is prevented. We are securing.

[0004]

As described above, in a conventional pump casing made of a press, rigidity of the pump casing is ensured in order to prevent deformation of the liner portion of the pump casing. Therefore, the suction flange and the pump casing have to be reinforced by providing a reinforcing member having a thickness greater than the required strength against the internal pressure and having a complicated shape. Therefore, press forming becomes difficult due to an increase in the plate thickness, and a reinforcing member having a complicated shape is provided, so that there has been a problem that the manufacturing cost increases.

The present invention has been made in view of the above circumstances, and has as its object to suppress deformation of the liner portion of the pump casing and to have an appropriate plate thickness with respect to piping external force and internal pressure. It is another object of the present invention to provide a sheet metal pump casing which does not require an unnecessarily thick plate and does not require a reinforcing member for reinforcing the pump casing.

[0006]

In order to achieve the above-mentioned object, a sheet metal pump casing according to the present invention is provided in a sheet metal pump casing, wherein the outer casing is provided in the outer casing while being separated from the outer casing. An inner casing accommodating an impeller therein, the inner casing comprising a first inner casing provided on a suction side, and a second inner casing accommodating the impeller, wherein the first inner casing is provided. And a seal member made of an elastic material is interposed in a gap between the first casing and the outer casing, and a seal member made of an elastic material is interposed in a connection portion between the first inner casing and the second inner casing. Things.
The end of the inner casing opposite to the suction side is held directly or via another member having rigidity such as a motor bracket in the case of a motor direct drive type and a bearing bracket in the case of a motor direct drive type. Further, the inner casing forms a liner portion.

[0007]

According to the present invention having the above-described structure, the casing is divided into an outer casing and an inner casing, and the inner casing is divided into a first inner casing and a second inner casing. Since the divided portions where are formed are each sealed with a sealing member made of an elastic material, and at the same time, both ends of the first inner casing are supported by these elastic materials. It is absorbed by the displacement of the first inner casing and is not transmitted to the second inner casing. Therefore, there is no need to make the outer casing rigid,
There is no need to make the outer casing thicker than necessary,
Moreover, there is no need 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 loads such as external forces on the piping, the plate thickness can be reduced, and press molding is facilitated. As a result, it is easy to ensure the accuracy of press molding.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a sheet metal pump casing according to the present invention will be described below with reference to FIGS. FIG. 1 is a longitudinal sectional view showing a horizontal centrifugal pump installed on land equipped with a sheet metal pump casing of the present invention. In FIG. 1, reference numeral 1 denotes an outer casing, and the outer casing 1 is formed by deep drawing a single steel plate made of stainless steel or the like by pressing. The outer casing 1 has a cylindrical container-shaped main body 2, a cylindrical suction nozzle 3 extending from the main body 2 to the suction side, and a casing provided on the opening side opposite to the suction nozzle 3. And a flange 4. A discharge nozzle 5 is fixed to the cylindrical side wall of the main body 2 by welding or the like, and a discharge flange 6 is connected to a tip end of the discharge nozzle 5 by welding or the like. The suction nozzle 3 is composed of a different diameter nozzle having a large diameter portion 3a and a small diameter portion 3b.
The suction flange 7 is fixed to the tip of the head by welding or the like.

The casing flange 4 is fixed to and supported by the motor bracket 8 in the case of the direct motor type, and is fixed to the bearing bracket in the case of the direct motor type.
Similarly, the casing cover 9 fixed to the bracket 8
Is provided so as to close the opening of the outer casing 1.

On the other hand, an inner casing 10 is provided inside the outer casing 1. The inner casing 10 extends from the vicinity of the suction nozzle 3 to the vicinity of the impeller 14 and forms a cylindrical first inner casing 11 which forms a suction flow path.
A front end portion is fitted to the inner casing 11, and the cylindrical second inner casing 12 houses the impeller 14. A seal member 13 made of an elastic material is interposed in a gap between the suction side end of the first inner casing 11 and the suction nozzle 3 of the outer casing 1,
The suction side (low pressure side) and the discharge side (high pressure side) are sealed by the seal member 13. In addition, the sealing member 1
3 is pushed to the suction side by the pressure difference between the high-pressure side and the low-pressure side, so that it can be reliably sealed without falling off. In addition, a seal member 20 made of an elastic material is also interposed at a connection portion between the first inner casing 11 and the second inner casing 12.
The first inner casing 11 is pushed toward the second inner casing 12 by the differential pressure (high pressure and low pressure) applied to the area indicated by h in FIG. Function.

The open end of the second inner casing 12 is fitted to and supported by the casing cover 9. Since the casing cover 9 is held by the motor-side bracket 8 made of a casting or the like, the casing cover 9 has high rigidity, and the second inner casing 12 is supported by the casing cover 9 having high rigidity.

On the other hand, the impeller 14 is connected to and supported by the free end of the main shaft 15. The main shaft 15 is rotatably supported by bearings (not shown), and a shaft sealing device 16 is provided between the main shaft 15 and the casing cover 9. A guide device 17 forming a guide vane or a volute is installed inside the second inner casing 12,
A turning prevention plate 18 is fixed inside the first inner casing 11. The turning prevention plate 18 has a substantially U-shaped cross section as shown in FIG. 2, and is fixed to the first inner casing 11 at an outer end by welding or the like. The suction side end of the second inner casing 12 constitutes a liner portion L, and the impeller 1
A slight clearance is formed between the suction side edge 14a and the liner L.

The operation of the centrifugal pump will be described briefly. The fluid sucked from the suction nozzle 3 is guided into the impeller 14 through the first inner casing 11. The fluid discharged from the rotating impeller 14 is subjected to pressure recovery by the guide device 17, and the outer casing 1 and the inner casing 10 are opened through an opening 12 a formed in the second inner casing 12.
(Consisting of the first inner casing 11 and the second inner casing 12), and then the outer casing 1
From the discharge port 2a formed through the discharge nozzle 5 to a discharge pipe (not shown). The fluid flowing from the inner casing 10 into the space between the outer casing 1 and the inner casing 10 is prevented from flowing into the suction side by the seal members 13 and 20. Note that a guide plate 19 for guiding the fluid discharged from the inner casing 10 to the discharge nozzle 5 as shown by a virtual line may be provided.

In this embodiment, the casing is divided into an outer casing 1 and an inner casing 10, and the inner casing 10 is further divided into a first inner casing 11 and a second inner casing 12, so that a differential pressure between suction and discharge is obtained. Where the split occurs
At the same time as sealing with the sealing members 13 and 20 made of elastic material, both ends of the first inner casing 11 are supported by these elastic materials in a floating state. Therefore, even if the outer casing 1 is deformed (from a solid line position to a broken line position in FIG. 3) due to a pipe load or the like, as shown in FIG.
The second casing 12 is not deformed because it can be freely displaced by tilting around the fulcrum 2 (from the solid line position to the broken line position in FIG. 3). Further, since the internal pressure load applied to the inner casing 10 is small (only the first inner casing 11),
The deformation of the inner casing itself is also small. Therefore, the clearance of the rotating body sliding portion between the second inner casing 12 and the impeller 14 constituting the liner portion can be secured, and the second inner casing 12 does not contact the impeller 14.

Next, another embodiment of the present invention will be described with reference to FIG. FIG. 4 is a cross-sectional view showing an all circumferential flow type inline pump including the sheet metal pump casing of the present invention. The in-line pump shown in this embodiment includes a suction-side outer casing 21, a discharge-side casing 40, and an outer cylinder 41 that connects between the suction-side outer casing 21 and the discharge-side casing 40. The suction side outer casing 21 and the outer cylinder 41 are connected by flanges 45, 45, and the discharge side casing 40 and the outer cylinder 41 are connected by flanges 46, 46, respectively. An outer casing is constituted by the outer casing 21 on the suction side, the casing 40 on the discharge side, and the outer cylinder 41, and a canned motor 42 is provided in the casing. Since the can motor 42 uses a general can motor, its details are not shown in FIG. A suction flange 48 and a discharge flange 49 are fixed to the suction side outer casing 21 and the discharge side casing 40, respectively.

The suction side outer casing 21 includes a main body 22 having a truncated frustoconical shape, a cylindrical suction nozzle 23 extending from the main body 22 to the suction side, and a suction nozzle 23.
Flange 2 provided on the opening side opposite to
4 is provided.

On the other hand, an inner casing 30 is provided inside the outer casing 21 on the suction side. The inner casing 30 comprises a cylindrical first inner casing 31 and a container-like second inner casing 32, as in the embodiment of FIG. A seal member 13 made of an elastic material is interposed in a gap between the suction side end of the first inner casing 31 and the suction nozzle 23 of the suction side outer casing 21.
The suction side (low pressure side) and the discharge side (high pressure side) are sealed by the seal member 13. Further, a seal member 20 made of an elastic material is also interposed at a connection portion between the first inner casing 31 and the second inner casing 32.

A guide device 33 constituting a guide vane or volute is provided inside the second inner casing 32. The guide device 33 has a spigot fitting portion, and the spigot fitting portion is fitted to the outer cylinder of the canned motor 42. The outer cylinder of the canned motor 42 has high rigidity, and the guide device 33 is supported by the outer cylinder.
As a result, the inner casing 30 is supported by the outer cylinder of the can motor 42 having high rigidity.

Inside the second inner casing 32, the impeller 1
The impeller 14 is connected to and supported by the main shaft 15 of the canned motor 42. FIG.
As in the embodiment shown in FIG. 7, the turning prevention plate 18 is fixed inside the first inner casing 31. The suction side end of the second inner casing 32 constitutes a liner portion L, and the impeller 14
A slight clearance is formed between the suction side edge portion 14a and the liner portion L.

The operation of the in-line pump will be briefly described. The fluid sucked from the suction nozzle 23 is the first fluid.
It is guided into the impeller 14 through the inner casing 31. Fluid discharged from the rotating impeller 14 is guided by the guide device 33.
After the flow direction is changed from the radial direction to the axial direction via
The fluid flows into a flow path 43 formed between the outer cylinder 41 and the canned motor 42, and flows into the discharge side casing 40 through the flow path 43. Then, it is discharged from a discharge nozzle 47 formed integrally with the discharge side casing 40.

In this embodiment, as in the embodiment shown in FIG. 1, the suction side casing is divided into an outer casing 21 and an inner casing 30, and the inner casing 30 is further divided into a first inner casing 31 and a second inner casing 32. The divided portion in which the differential pressure between suction and discharge is generated is sealed by the sealing members 13 and 20 made of elastic material, and at the same time, the first inner casing 31 is supported in a floating state by these elastic materials. . Therefore, even if the outer casing 21 is deformed by a pipe load or the like, the first inner casing 3
The first inner casing 32 can be freely displaced while being inclined about the second inner casing 32 as a fulcrum, so that the second inner casing 32 is not deformed. Therefore, the clearance of the rotating body sliding portion between the second inner casing 32 forming the liner portion L and the impeller 14 can be secured, and the second inner casing 32 is
No contact with 4.

[0022]

As described above, according to the present invention,
Split the casing into an outer casing and an inner casing,
Since a seal member made of an elastic material is interposed between the outer casing and the inner casing, even if the outer casing is deformed due to an external force of the pipe, the deformation is absorbed by the displacement of the first inner casing and transmitted to the second inner casing. Nothing.
Also, since the inner pressure load applied to the inner casing is small, the deformation of the inner casing itself is also small. Therefore, the outer casing only needs to have an appropriate plate thickness for loads such as pipe external force and internal pressure, and it is not necessary to increase the plate thickness more than necessary to secure rigidity. No need to reinforce. Therefore, press molding becomes easy, and a pump casing with high productivity can be obtained. Moreover, since there is no need to provide a reinforcing member in the casing, cost reduction can be achieved by reducing the number of parts. Further, the outer casing can be formed in a simple shape independent of the guide device, and processing accuracy such as securing concentricity is not required.

Further, since the inner casing constitutes the liner portion, it is easy to secure the clearance of the liner portion. Further, 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 performed. And the accuracy of press molding is easily ensured.

Further, since the inner casing is divided into the first inner casing and the second inner casing, the respective forming draw ratios (H / D) are smaller than when the inner casing is manufactured integrally. , And press forming becomes easy. In addition, the first inner casing on the suction side is small, and mounting and welding work of the turning prevention plate is facilitated.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a horizontal pump installed on land provided with a sheet metal pump casing according to the present invention.

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

FIG. 3 is an explanatory view when an external force is applied to the outer casing in the embodiment shown in FIG. 1;

FIG. 4 is a cross-sectional view of an all circumferential flow type inline pump including a sheet metal pump casing according to the present invention.

FIG. 5 is a sectional view showing an example of a conventional sheet metal pump casing.

[Explanation of symbols]

 1, 21 Outer casing 2, 22 Main body 3, 23 Suction nozzle 4, 24 Casing flange 5 Discharge nozzle 6 Discharge flange 7 Suction nozzle 8 Bracket 9 Casing cover 10, 30, Inner casing 11, 31 First inner casing 12, 32 First 2 inner casing 13 seal member 14 impeller 15 main shaft 16 shaft sealing device 17, 33 guide device 40 discharge side casing 41 outer cylinder 42 canned motor 43 flow path

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-130599 (JP, A) JP-A-3-47499 (JP, A) Fully open 1979-47102 (JP, U) Fully open 1979 34002 (JP, U) WO 89/8195 (WO, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) F04D 29/42

Claims (3)

(57) [Claims] 1. A sheet metal pump casing, comprising an outer Ke <br/> pacing, and a casing inner housing the impeller therein provided in the outer casing in a state of being spaced apart from the outer casing, the The inner casing includes a first inner casing provided on the suction side, and a second inner casing containing the impeller, and a seal member made of an elastic material is provided in a gap between the first inner casing and the outer casing. A pump casing made of sheet metal, wherein a sealing member made of an elastic material is interposed at a connection portion between the first inner casing and the second inner casing. 2. The non-suction side end of the second inner casing is held directly or via another member having rigidity such as a motor bracket in the case of a direct drive motor and a bearing bracket in the case of a direct drive motor. The sheet metal pump casing according to claim 1, wherein 3. The sheet metal pump casing according to claim 1, wherein said second inner casing constitutes a liner portion.