JPH0337399A - Centrifugal pump casing - Google Patents

Abstract

PURPOSE:To enable high accuracy assembly by forming a plurality of reinforcing members extending to a casing shell side around the outer circumference of a coupled flange fixed on the pump suction port of the casing shell, and welding a connecting ring provided on respective parts of the reinforcing members on a casing shell outer surface. CONSTITUTION:A casing shell 1 in which a fixed flange 2 is provided on one side thereof and a pump suction port 3 is provided on other side thereof, is formed so that a steel plate is deep-drawn by a press. An impeller 5 is provided integratedly with a boss 6, on the inner side of the casing shell 1. In this case, a coupled flange 10 formed by pressing as an other member, is connected to the pump suction port 3 of the casing shell 1, and a suction port 11 is opened on the center thereof. On the several parts around the outer circumference part 10a of the coupled flange 10, reinforcing members 18 extending integratedly to the casing shell 1 side are formed, and connecting rings 19 provided on the end part thereof is fixed by welding on the outer circumference surface of the casing shell 1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a centrifugal pump casing, and more particularly to a centrifugal pump casing in which the connection between the casing acid and the connecting flange is strengthened.

[Conventional technology]

Generally, a centrifugal pump casing is known in which a steel plate is deep-drawn using a press to form a casing acid, a pump suction port is opened in the casing acid, and a connecting flange is connected to the pump suction port by welding. .

In this type of device, reinforcing means are taken to strengthen the bond between the casing acid and the connecting flange in order to prevent the connecting flange from deforming.

As a conventional reinforcing means, as shown in FIG. 5, a plurality of reinforcing pieces 30, 30...30 are prepared, one end 30a of these reinforcing pieces 30 is fixed to a connecting flange 31 by welding, The other end 30b is fixed to the casing acid 32 by welding.

According to this, an opening 33 is defined between the reinforcing pieces 30. This opening 33 is connected to the connecting flange 3
When connecting 1 and a companion flange (not shown) with bolts and nuts, this becomes a working space for inserting a tool to turn the nut.

[Problem to be solved by the invention]

However, the above-mentioned reinforcing means requires many welding points and is cumbersome to work with.
There is a problem in that it is difficult to achieve parallelism with

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned problems of the conventional technology, strengthen the bond between the casing acid and the connecting flange, reduce the number of welding points, and improve workability. To provide a centrifugal pump casing in which parallelism between a sealing surface of a flange and a vertical surface of a casing shell can be easily and precisely achieved.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a centrifugal pump made by deep drawing a steel plate using a press to form a casing acid with a pump suction port opened, and fixing a connecting flange to the pump suction port of the casing shell by welding. In the pump casing, a plurality of reinforcing members extending toward the casing shell are integrally formed on the outer periphery of the connecting flange, and a connecting ring is integrally formed at each end of these reinforcing members, and this connecting ring is attached to the casing shell. It is characterized by being fixed to the outer surface of the material by welding.

[For production]

According to the present invention, the connecting flange, the reinforcing member, and the connecting ring are formed as one piece, and this connecting ring is fixed to the outer surface of the casing shell by welding, so that the connection between the casing acid and the connecting flange is extremely strong. become,
Deformation of the connecting flange is reliably prevented. In addition, since the overall structure is formed as a frame with openings at four locations, it is possible to align the sealing surface of the connecting flange and the end surface of the connecting ring in advance so that they are parallel to the outside of the casing shell. By simply welding to the surface, the parallelism between the sealing surface and the vertical plane of the casing shell can be achieved with high accuracy.

〔Example〕

Hereinafter, one embodiment of a 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 acid of a centrifugal pump, and this casing acid 1 is formed by deep drawing a single steel plate using a press. A fixed flange 2 is integrally formed at one end of the casing acid 1, and a pump 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.

In addition, a volute chamber A is formed in the center inside the casing acid 1, and the outer periphery of this volute chamber A is connected to the overhanging portion 1.
It is defined by a. This projecting portion 1a is formed by expanding the outer peripheral wall of the casing acid 1 radially outward. As shown in FIG. 2, the overhang height of the overhang part 1a starts to overhang from the middle and increases continuously along the circumferential direction (counterclockwise in the figure). The cross-sectional area of the flow path 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.

A connecting flange 10 formed by press as a separate member is connected to the pump suction port 3 of the casing acid 1, and a suction port 11 is opened in the center of the connecting flange 10. A sealing surface 12 for connecting a companion flange (not shown) is formed on this connecting flange 10,
As shown in FIG. 2, a reinforcing flange 13 having a substantially rectangular outer shape is fixed to the back side of the sealing surface 12. Furthermore, as is clear from FIG. 3, the connecting flange 10 is provided with four bolt holes 14, and the reinforcing flange 13 is provided with four bolt holes aligned with the bolt holes 14. A through hole 15 is bored.

Here, FIG. 3 shows a cross section taken along the line ■-■ in FIG. The nut 16, which is shown in phantom, is not fixed thereto, but is prepared when connecting a companion flange (not shown) to the connecting flange 10.

The external shape of the 12 sealing surfaces of the connecting flange 10 is formed into a rectangular shape, and as is clear from FIG. Four reinforcing members 18 are formed which extend outwardly. Furthermore, a connecting ring 19 is integrally formed at each end of these reinforcing members 18, and this connecting ring 19 is fixed to the outer peripheral surface of the casing shell 1 by welding. According to this, the connecting flange 10, the reinforcing member 18, and the connecting ring 19 are integrally formed, and the whole is formed as a frame having openings 20 at four locations.

The opening 20 has a height h and a width W and is formed as a cavity for inserting a tool when turning the nut 16 (FIG. 3).

When connecting a companion flange (not shown) to the connecting flange 10, align the sealing surface of the companion flange with the sealing surface 12, and insert bolts (not shown) from the companion flange side through the bolt holes 14 and through holes 15. Insert the bolt and screw the nut 16 onto the bolt to connect.

Each side edge 18a of the reinforcing member 18 defining the opening 20
is bent inward at a substantially right angle, and the end edge 18b of the reinforcing member 18 located on the casing shell 1 side is bent inward and along the outer surface of the casing shell 1. This is to increase the rigidity and strength of the reinforcing member 18, and as is clear from FIG. It is designed to connect to. Connection flange 10
The edge of the reinforcing member 18 located on the side is simply cut off without being bent.

Further, on the outer surface of the casing shell 1, drain plugs 21 and air vents 22 are provided on the upper and lower sides, respectively. In this embodiment, the outer shape of the connecting flange 10 is approximately rectangular due to the provision of these plugs 21 and 22, but if there are no dimensional restrictions, the outer shape may be made circular, for example. It is.

As shown in FIG. 2, one end 23a of a nozzle 23 is connected to the highest overhang 1a of the casing shell 1, and a discharge flange 24 is connected to the other end 23b of the nozzle 23.
A discharge port 25 is opened in the center of the discharge flange 24 . The structure of the discharge flange 24 itself is the connecting flange 1.
Since the structure is the same as that of 0, the explanation 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 electric 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 pump suction port 3. This inhaled fluid is
It 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. This discharged fluid moves in the circumferential direction (counterclockwise in FIG. 2) within the volute chamber A, passes through the nozzle 23, and passes through the discharge flange 24.
is discharged from the discharge port 25.

According to this embodiment, the connecting flange 10, the reinforcing member 18, and the connecting ring 19 are integrally formed, and the connecting ring 19 is fixed to the outer surface of the casing shell 1 by welding. The connection between the shell 1 and the connecting flange 10 can be made extremely strong,
Deformation of the connecting flange 10 can be reliably prevented.

In addition, since the overall body is formed as a frame having openings 2o at four locations, if the parallelism between the sealing surface 12 of the connecting flange 10 and the end surface of the connecting ring 19 is established in advance, this can be done easily. by simply welding the sealing surface 12 and the casing acid 1 to the outer surface of the casing shell 1.
The parallelism with the vertical plane can be achieved with high accuracy.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, a plurality of reinforcing members extending toward the casing shell are integrally formed on the outer periphery of the connecting flange, and a connecting ring is integrally provided at each end of these reinforcing members. Since this connecting ring is fixed to the outer surface of the casing shell by welding, it is possible to strengthen the bond between the casing acid and the connecting flange, and also to ensure that the sealing surface of the connecting flange and the vertical direction of the casing shell are Parallelism with the surface can be easily and precisely determined.

According to another invention, each side edge of the reinforcing member is bent inward at a substantially right angle, and the edge of the reinforcing member located on the casing shell side is bent inward and along the outer surface of the casing shell. The stiffness of the reinforcing member is increased, and the connection between the casing acid and the connecting flange can be further strengthened.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of a centrifugal pump casing according to the present invention, FIG. 2 is a front view of the same, and FIG.
4 is a perspective view of the casing seen from the suction side, and FIG. 5 is a side view showing a conventional centrifugal pump casing. 1...Casing acid, 3...Pump suction port, 10.
...Connection flange, 12...Sealing surface, 13...
- Reinforcement flange, 18... Reinforcement member, 18a, 18a
...Side edge, 18b... End edge, 19... Connection ring, 20... Opening, 25... Discharge flange.

Claims (1)

[Claims] 1. A centrifugal pump casing in which a steel plate is deep-drawn using a press to form a casing shell with an open pump suction port, and a connecting flange is fixed to the pump suction port of the casing shell by welding. , a plurality of reinforcing members extending toward the casing shell are integrally formed on the outer periphery of the connecting flange, and a connecting ring is integrally formed at each end of the reinforcing members, and the connecting ring is connected to the casing shell. A centrifugal pump casing characterized by being fixed to the outer surface of the pump by welding. 2. Each side edge of the reinforcing member is bent inward at a substantially right angle, and the edge of the reinforcing member located on the casing shell side is bent inward and along the outer surface of the casing shell. The centrifugal pump casing according to claim 1.