JPH0738694U - Centrifugal pump steel impeller - Google Patents

Abstract

(57) [Abstract] [Purpose] The purpose is to improve the assembly accuracy and assemblability of a steel impeller. [Structure] A plurality of blade mounting holes 4 are formed by cutting and raising in a front shroud 1 and a rear shroud 2 of a steel impeller. It is characterized in that the projections 6 inserted in 4 are welded to the front shroud 1 and the rear shroud 2 to attach the blades 3 to the front shroud 1 and the rear shroud 2.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a steel impeller of a centrifugal pump.

[0002]

[Prior art]

 Generally, a steel impeller of a centrifugal pump is provided between a front shroud having a suction port in the center, a rear shroud arranged behind the front shroud, and between the rear shroud and the front shroud. The front shroud, the rear shroud and the blades are all formed by pressing a steel plate.

By the way, when assembling such a steel impeller, first, a plurality of blade mounting holes are formed in the front shroud and the rear shroud by punching. Then insert the blade protrusions into these blade mounting holes and arc spot weld the blade protrusions inserted into the blade mounting holes to the front shroud and rear shroud to attach the blades to the front shroud and rear shroud. A common method is to attach it to the.

[0004]

[Problems to be solved by the device]

 However, according to such a method, there is no problem when the blade is press-formed in two dimensions, but when the blade is press-formed in three dimensions, the blade protrusion is not attached to the blade mounting hole. Since it is inserted at an angle to, the blade mounting hole must be enlarged. As a result, a gap is created between the blade protrusion and the blade mounting hole, and this gap causes the blade to move during assembly, and the blade should be attached to the front shroud and rear shroud at a specified angle. Was difficult.

Further, when the protrusion of the blade is obliquely inserted into the blade mounting hole, when the protrusion of the blade inserted into the blade mounting hole is welded to the front shroud and the rear shroud by arc spot welding. In addition, since the molten metal flows along the inclined surface of the protrusion, it is difficult to close the gap generated between the protrusion and the blade mounting hole with the molten metal.

The present invention has been made in view of the above problems, and an object thereof is to assemble a steel impeller without changing the blade mounting angle due to movement of the blade during assembly. It is an object of the present invention to provide a steel impeller of a centrifugal pump that can improve accuracy and assemblability.

[0007]

[Means for Solving the Problems]

 In order to solve the above problems, the present invention has a front shroud which has a suction port in the center and is formed by press working a steel plate, and is arranged on the rear side of this front shroud, and presses the steel plate. A steel impeller of a centrifugal pump, comprising a rear shroud formed, and a plurality of blades formed between the rear shroud and the front shroud and formed by pressing a steel plate. A plurality of blade mounting holes are formed on the front shroud and the rear shroud by cutting and raising, and the protrusions of the blades are inserted into these blade mounting holes, and the protrusions inserted into the blade mounting holes are connected to the front side. The blade is attached to the front shroud and the rear shroud by welding to the shroud and the rear shroud.

[0008]

[Action]

 In the present invention, when the protrusion of the blade is inserted into the blade mounting hole, the protrusion of the blade is positioned by the cut-and-raised portion, so that the blade may move during the assembly to change the mounting angle of the blade. Disappears.

[0009]

【Example】

 An embodiment of the present invention will be described below with reference to FIGS. As shown in FIGS. 1 and 2, a steel impeller for a centrifugal pump according to an embodiment of the present invention is provided with a front shroud 1 having a suction port 1a in the center and a rear side of the front shroud 1. It comprises a rear shroud 2 and a plurality of blades 3 provided between the rear shroud 2 and the front shroud 1. The front shroud 1, the rear shroud 2 and the blade 3 are all made of a tertiary steel plate. Originally formed by press molding.

When assembling such a steel impeller, first, as shown in FIG. 3 (a), a plurality of blade mounting holes 4 are formed in the front shroud 1 and the rear shroud 2 by cutting and raising them. At this time, the cut-and-raised angle α of the cut-and-raised portion 5 is set to match the mounting angle of the blade 4.

Next, the protrusions 6 of the blade 3 are inserted into these blade attachment holes 4 (see FIG. 3B), and the protrusions 6 of the blade 3 inserted into the blade attachment holes 4 are front-sided by arc spot welding. It is welded to the shroud 1 and the rear shroud 2 (see FIG. 3 (c)).

At this time, the protrusion 6 of the blade 3 inserted into the blade mounting hole 4 is positioned by the cut-and-raised portion 5 as shown in FIG. 3B, so that the blade 3 moves during the assembly. Therefore, the mounting angle of the blade 3 does not change. Therefore, even if the blade 3 is formed by three-dimensionally press-forming a steel plate, the blade 3 can be attached to the front shroud 1 and the rear shroud 2 at a predetermined angle, and the steel impeller can be precisely manufactured. Good and easy to assemble.

In addition, in the above-described embodiment, when the blade 3 is attached to the front shroud 1 and the rear shroud 2, the projection 6 and the cut-and-raised portion 5 of the blade 3 are arc-spot welded. As shown in FIG. 3C, the blade mounting hole 4 can be completely closed with the molten metal 7.

[0014]

As described above, according to the present invention, the front shroud which has the suction port in the center and is formed by pressing the steel plate, and the rear shroud is disposed behind the front shroud, and the steel plate is pressed. In a steel impeller of a centrifugal pump, which is composed of a plurality of blades formed by pressing a steel plate, which is provided between the rear shroud and the front shroud. A plurality of blade mounting holes are formed in the front shroud and the rear shroud by cutting and raising, and the protrusions of the blade are inserted into these blade mounting holes, and the protrusions inserted into the blade mounting holes are formed. The blade is attached to the front shroud and the rear shroud by welding to the front shroud and the rear shroud. . Therefore, when the blade protrusion is inserted into the blade mounting hole, the blade protrusion is positioned by the cut-and-raised portion, so the blade does not move during assembly and the blade attachment angle does not change. Therefore, it is possible to improve the assembling accuracy and the assembling property of the steel impeller.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view of a steel impeller for a centrifugal pump according to an embodiment of the present invention.

2 is a sectional view of the steel impeller for a centrifugal pump taken along the line AA of FIG.

FIG. 3 is a view showing an assembling method of a steel impeller for a centrifugal pump according to the embodiment.

[Explanation of symbols]

 1 ... Front shroud 2 ... Rear shroud 3 ... Blade 4 ... Blade mounting hole 5 ... Cut and raised portion 6 ... Projection

Claims (1)

[Scope of utility model registration request] 1. A front shroud having a suction port in the center and formed by pressing a steel plate, and a rear shroud disposed behind the front shroud and formed by pressing a steel plate, A steel impeller of a centrifugal pump, which is provided between the rear shroud and the front shroud, and includes a plurality of blades formed by pressing a steel plate, wherein the front shroud and the rear shroud have a plurality of blades. The mounting holes are formed by cutting and raising, the projections of the blades are inserted into these blade mounting holes, and the projections protruding from the blade mounting holes are welded to the front shroud and the rear shroud to form the blades. Steel impeller for a centrifugal pump, characterized by being attached to the front shroud and the rear shroud.