JP3048675B2 - Electric centrifugal pump impeller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an impeller of an electric centrifugal pump, and more particularly to an impeller of an electric centrifugal pump which can be used for 50 Hz and 60 Hz.

[0002]

2. Description of the Related Art Conventionally, an impeller of an electric centrifugal pump is designed on the premise that the electric motor is rotated in a certain direction and used, and as shown in FIGS.
Is integrally cast with the shroud 2′b.

[0003]

When the frequency of the electric power used differs, the number of revolutions of the electric motor for driving the pump also changes. If the same impeller is rotated at a different frequency, for example, a 50 Hz operation at 60 Hz requires about 1.73 times the shaft power, and a 60 Hz operation at 50 Hz. In operation, about 0.58 times the shaft power is required. Therefore, it is necessary to change the blade width of the impeller or change the outer diameter of the impeller in order to fit within the shaft power determined corresponding to different frequencies. However, preparing impellers with different blade widths and outer diameters in advance and replacing them at the site of use in accordance with the frequency requires a corresponding amount of work time and labor, and has a problem in terms of maintainability. .

An object of the present invention is to provide an electric centrifugal pump in which the outer diameter of an impeller is automatically adjusted so as to be set within the shaft power and determined according to the frequency of electric power used without replacing the impeller. It is in.

[0005]

In the impeller of the electric centrifugal pump according to the present invention, the impeller is fitted to the pump shaft to maintain rigidity.
The rotating body is closed, to fix the inner end of the blade plate made of an elastic material such as rubber, it was to the aspects biasing the radial direction to slightly circumferentially outer end as a free end distracted.

[0006]

When the pump is driven, fluid pressure causes the blade to bend in the direction opposite to the direction of rotation of the rotating body. If the rotation direction of the motor is changed, the blades bend in the opposite direction due to the fluid pressure acting in the opposite direction. The discharge angle formed at the outer end of the blade when rotated in one direction is larger than the discharge angle formed at the outer end of the blade when rotated in the other direction.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments will be described below with reference to the drawings.

Reference numeral 1 denotes a rotating body fitted to the pump shaft 2, which is formed by integrally molding the boss portion 1a and the shroud 1b, but is not necessarily made of metal and requires a mandrel. The main material may be rubber or the like as long as it is made rigid by molding or by abutment of a reinforcing plate on the surface. 3
No. 3 is a blade made of an elastic material such as rubber, in which the inner end is fixed to the rotating body 1 and the outer end is free end slightly deviated from the radial direction to the circumferential direction. To distract. Although the drawings of the embodiment show a mode in which the inner ends of the slats 3 # 3 are fixed to the surface of the shroud 1b, they may be fixed to the outer periphery of the boss 1a. Further, the fixing method is not limited to such means as adhesion, fitting, screwing, and the like.

When the pump is driven by the forward rotation of the electric motor, the rotating body 1 rotates in the direction indicated by the arrow as shown in FIG. 3, and the respective blades 3 # 3 rotate in the direction opposite to the rotating direction of the rotating body 1 due to the fluid pressure. And a discharge angle β ₁ is formed. Also, when the pump is driven by reverse rotation while changing the connection of the motor, the rotating body 1 rotates in the direction indicated by the arrow shown in FIG. The ejection angle β ₂ is formed by bending in the opposite direction. In order to make the discharge angle β ₁ formed at the time of normal rotation of FIG. 3 larger than the discharge angle β ₂ formed at the time of reverse rotation of FIG.
As shown in FIG. 1, the outer ends of the slats 3 # 3 are previously extended in such a manner that they are slightly offset in the circumferential direction from the radial direction.

The rotation trajectory drawn by the outer end of the blade plate 3 で 3 at a large discharge angle β ₁ is equal to the rotation locus of the blade plate 3 at a small discharge angle β _2.
# 3 is larger than the rotation locus drawn by the outer end. Slat 3
The fact that the rotation locus described by # 3 is large means that the outer diameter of the impeller is substantially large, which means that the impeller was placed in an appropriate state for 50 Hz. In addition, the fact that the rotation locus drawn by the blade plate 3 # 3 is small means that the outer diameter of the impeller is substantially small, which means that the impeller is placed in an appropriate state for 60 Hz.

As described above, by switching the rotation direction of the electric motor in the forward and reverse directions, the outer diameter of the impeller is substantially increased or decreased, so that the impeller can be used for both 60 Hz and 50 Hz.

[0012]

When the impeller of the present invention is used, the state of the impeller is automatically changed between 50 Hz and 60 Hz simply by switching the direction of rotation of the electric motor between forward and reverse. There is no need to prepare an impeller, and there is an advantage that the number and labor of replacing the impeller can be reduced, and a highly practical electric centrifugal pump excellent in maintainability can be provided.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view of a main part of an impeller of the present invention.

FIG. 2 is a plan view of the impeller of the present invention as viewed from the blade plate side.

FIG. 3 is an explanatory diagram showing a mode of bending of a blade plate during normal rotation of the impeller of the present invention.

FIG. 4 is an explanatory view showing a bending mode of a blade plate when the impeller of the present invention rotates in the reverse direction.

FIG. 5 is a vertical sectional side view of a main part of a conventional impeller.

FIG. 6 is a plan view of a conventional impeller viewed from a blade plate direction.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotating body 2 Pump shaft 3 Blade plate

Claims (1)

(57) [Claims] An inner end of a blade (3) made of an elastic material such as rubber is fixed to a rotating body (1) fitted to a pump shaft (2) and having rigidity. is allowed, characterized in that was to the aspects biasing the radial direction to slightly circumferentially outer end as a free end distracted, electrostatic dynamic centrifugal pump impeller.