JPH0579837B2 - - Google Patents

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 shell and the connecting flange is strengthened.

[Conventional technology]

Generally, a centrifugal pump casing is known, which is formed by deep drawing a steel plate using a press to form a casing shell, opening a pump suction port in the casing shell, and joining a connecting flange to the pump suction port by welding. .

In this type, reinforcing means are provided to strengthen the connection between the casing shell 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, . The end 30b is fixed to the casing shell 32 by welding. According to this, an opening 33 is defined between the reinforcing pieces 30. This opening 33
is the connecting flange 31 and the companion flange (not shown)
When connecting the two with bolts and nuts, it becomes a working space for inserting the 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 the vertical surface 32a of No. 2.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned problems of the conventional technology, strengthen the connection between the casing shell 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 in which a steel plate is deep drawn using a press to form a casing shell with a pump suction port opened, and a connecting flange is fixed 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.

[Effect]

According to the present invention, the connecting flange, the reinforcing member, and the connecting ring are integrally formed, and the connecting ring is fixed to the outer surface of the casing shell by welding, so that the connection between the casing shell and the connecting flange is extremely strong. Therefore, deformation of the connecting flange is reliably prevented. In addition, since the overall structure is formed as a frame with openings in four places,
If the parallelism between the sealing surface of the connecting flange and the end surface of the connecting ring is determined in advance, then by simply welding it to the outer surface of the casing shell, the parallelism between the sealing surface and the vertical plane of the casing shell can be established. It is possible to accurately measure the degree.

〔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 shell of a centrifugal pump, and this casing shell 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 shell 1, and a pump 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.

Further, a volute chamber A is formed in the center inside the casing shell 1, and the outer periphery of the volute chamber A is defined by an overhanging portion 1a. The projecting portion 1a is formed by bulging the outer circumferential wall of the casing shell 1 radially outward. Overhang part 1
As shown in Fig. 2, the height of the overhang of volute chamber A starts from the middle and increases continuously along the circumferential direction (counterclockwise in the figure). The cross-sectional area of the passage 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.

A connecting flange 10 formed by press as a separate member is connected to the pump suction port 3 of the casing shell 1, and a suction port 11 is opened in the center of the connecting flange 10. This connecting flange 10 is formed with a sealing surface 12 for connecting a companion flange (not shown), and on the back side of this sealing surface 12, as shown in FIG. A flange 13 is fixed. 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. Through hole 1
5 is drilled.

Here, FIG. 3 shows a - cross section of FIG. 2. The nut 16 shown in phantom lines is not fixed thereto, but is attached to the connecting flange 1.
It is prepared when connecting a companion flange (not shown) to 0.

The outer shape of the connecting flange 10 on the side of the sealing surface 12 is formed into a substantially rectangular shape, and as is clear from FIG. Four reinforcing members 18 are formed that extend to. 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 and the reinforcing member 18
The connecting ring 19 is 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 designed as a cavity for inserting a tool when turning the nut 16 (FIG. 3). A companion flange (not shown) is attached to the connecting flange 10.
When connecting, align the sealing surface of the companion flange with the sealing surface 12, insert a bolt (not shown) from the companion flange side through the bolt hole 14 and through hole 15, and insert the nut 16 into this bolt.
Connect by screwing them together.

Each side edge 18a of the reinforcing member 18 defining the opening 20 is bent inward at a substantially right angle.
b 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 each side edge 1
As is clear from FIG. 4, the respective ends of 8a, 18a and edge 18b are formed so as to be continuously and integrally connected. The edge of the reinforcing member 18 located on the side of the connecting flange 10 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, since the plugs 21 and 22 are provided, the outer shape of the connecting flange 10 is approximately rectangular.
If there are no dimensional restrictions, the outer shape may be circular, for example.

The highest overhang 1a of the casing shell 1 includes:
As shown in FIG. 2, one end 23a of the nozzle 23 is connected, a discharge flange 24 is connected to the other end 23b of the nozzle 23, and a discharge port 25 is opened in the center of the discharge flange 24. The structure of the discharge flange 24 itself is the same as the structure 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 pump suction port 3. This sucked fluid passes through the inside of the impeller 5, is applied with 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 1
0. Since the reinforcing member 18 and the connecting ring 19 are formed as one piece, and this connecting ring 19 is fixed to the outer surface of the casing shell 1 by welding, the connection between the casing shell 1 and the connecting flange 10 is extremely strong. Therefore, deformation of the connecting flange 10 can be reliably prevented.

In addition, since the overall body is formed as a frame having openings 20 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 to the outer surface of the casing shell 1, the parallelism between the sealing surface 12 and the vertical plane of the casing shell 1 can be achieved with high precision.

〔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 the connecting ring is fixed to the outer surface of the casing shell by welding, the connection between the casing shell and the connecting flange can be strengthened, and the sealing surface of the connecting flange and the vertical direction of the casing shell can be strengthened. 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 shell and the connecting flange can be further strengthened.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view showing an embodiment of a centrifugal pump casing according to the present invention, Fig. 2 is a front view thereof, Fig. 3 is a sectional view taken from the side shown in Fig. 2, and Fig. 4 is a view from the suction side of the casing. FIG. 5 is a side view showing a conventional centrifugal pump casing. 1...Casing shell, 3...Pump suction port, 1
0... Connection flange, 12... Sealing surface, 1
3... Reinforcement flange, 18... Reinforcement member, 18
a, 18a... side 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 a pump suction port opened, 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 these reinforcing members, and the connecting ring is connected to the casing shell. A centrifugal pump casing characterized by being fixed to the outer surface 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.