JPS6085288A - Impeller of wesco pump - Google Patents

Abstract

PURPOSE:To prevent metallic noise by providing various grooves having different width at the opposite sides of the outercircumferential edge of impeller such that the row pitch will be at the maximum. CONSTITUTION:The vane section of impeller is constructed with two types of groove 11, 12 having different width of 1/2l and 3/2l arranged such that the pitch of continuous groove is P2. When making two types of groove such that the pitch P2 of continuous groove will be at the maximum, the noise frequency to be determined by the basic frequency = number of vanes X rotation is varied to low frequency of 125-500Hz which is 1/8 of conventional level, thereby perceptible metallic noise can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an impeller for a Wesco pump used in well pumps and the like.

Conventional configurations and their problems Conventionally, this type of pump has a configuration as shown in FIG. 1, as an example. That is, the casing 1 has a partition wall 2
A suction port 3 and a discharge port 4 are formed, which are separated by an inlet port 3, and by rotating an impeller 6 attached to a drive shaft 6 in the direction of the arrow shown in the figure, the water sucked in from the suction port 3 in the direction of the arrow shown in the figure is While being pressurized by the impeller 6, the water passes through the water passage 8 and is discharged from the discharge port 4 in the direction of the arrow in the figure.

Further, as shown in FIG. 2, the impeller 6 has grooves 9 carved all around its outer peripheral edge on both sides to form a blade 1o. As shown in FIG. 3, the blades 1o of the impeller 6 are formed by cutting a large number of grooves 9 of the same shape and width l with the same pinch P1.

When the Wesco pump with such a configuration is in operation, there is a pressure difference before and after the blade 1o, so every time the blade 10 passes the partition wall 2, the pressure difference hits the partition wall 8.
This generates a noise called the so-called metallic sound of the Wesco pump, whose fundamental frequency is the number of blades multiplied by the number of revolutions. The fundamental frequency of this metallic sound is generally 2KHz to 4KHz, which tends to resonate with structures such as pump piping and steel buildings.
Because it is a high-frequency sound, compared to cavitation, which is a typical pump noise, it is easily transmitted without being attenuated even at a distance from the pump, and can cause unexpected noise pollution.

In order to eliminate the above-mentioned metal noise, countermeasures have been taken so far, such as attaching a cushioning material to the partition wall 2 or making the facing shape of the partition wall 20 blades 10- into a tapered shape to alleviate pressure fluctuations, but in both cases, the metal noise Since the sound is generated in a very localized area, it is difficult to achieve a wide-scale metallic sound reduction effect even if the above-mentioned measures are taken in a narrow area.

OBJECTS OF THE INVENTION The present invention takes these conventional problems into consideration and provides a low-noise impeller for a Wesco pump that significantly reduces metallic noise.

Structure of the Invention In order to achieve the above object, the present invention provides a plurality of types of grooves having different groove widths on both sides of the outer periphery of a plurality of impellers, and an arrangement in which the pitch of the rows of the plurality of types of grooves is a maximum value. This structure has grooves, which lowers the frequency of the generated noise and eliminates resonance with the piping, resulting in lower noise.

DESCRIPTION OF EMBODIMENTS Hereinafter, one embodiment of the present invention will be described with reference to FIG. 4.
The figure is a developed view corresponding to FIG. 2 of an impeller according to an embodiment of the present invention. As shown in the figure, the blade part of the impeller is composed of two types of grooves 11 and 12 with groove widths -+l and +β, and the arrangement is as follows, and the pitch of successive identical grooves lI'
By arranging and carving the two types of groove widths in such a way that the pitch of the same continuous groove becomes maximum, it becomes iP2, compared to the pitch P1 of the conventional example shown in FIG. = Pt, and the number of metallic sounds is eight times as large.
The frequency, which is determined by the number of blades x the number of rotations and two fundamental frequencies, changes to a low frequency sound of 126 to 500 Hz, which is 1/8 of the conventional sound.

Even if the sound pressure level is the same, the frequency is lower as described above, so the loudness of the sound as judged by human senses5
In other words, the metallic sound becomes smaller, and again.

Pump piping, buildings such as steel buildings, etc. will no longer resonate at their high frequency natural frequencies. Furthermore, the original flow rate-pressure performance of the pump does not change compared to the conventional pump performance because the groove width l of the conventional impeller is divided into +l and +l and the number of blades is the same.

In this embodiment, there are two types of groove widths, but it goes without saying that if the number of groove widths is increased to three or more, the noise performance will be the same or even lower. And the manufacturing cost is also + by setting the groove width to +4 and its multiple of 1g as in this example.
Two types of groove widths can be efficiently processed by simply changing the feed rate of the 6-width groove cutter, so there is not much difference from the conventional method.

Effects of the Invention As is clear from the description of the embodiments above, the present invention reduces the metallic noise of the Wesco pump and improves the piping and It is possible to make structures such as steel buildings less likely to resonate, and the effect is great.

[Brief explanation of the drawing]

Fig. 1 is a front sectional view of a conventional Wesco pump, Fig. 2 is a sectional view taken along the line DD of the impeller in Fig. 1, and Fig. 3 is a developed view of the conventional impeller as viewed from the arrow in Fig. 2. FIG. 4 is a developed view corresponding to FIG. 2 of the impeller of the Wesco pump of the present invention. 11.12...Groove, Pl, Pt...Pitch of the same continuous groove.

Claims (1)

[Claims] A Wesco pump characterized in that a plurality of grooves of different groove widths are provided on both sides of the outer periphery of the impeller body, and the grooves are arranged in an arrangement such that the pinch of the rows of the plurality of grooves is maximum. impeller.