TWI725016B - Impeller for centrifugal pumps - Google Patents

Abstract

An impeller for centrifugal pumps has a first disk element, functionally arranged toward the inlet, which is coaxial to and faces a second disk element, which is functionally arranged toward the delivery and is connected rigidly to the first disk element by virtue of a series of angularly spaced vanes and is provided centrally with a means for fixing to a transmission shaft, The particularity of the present invention resides in that the impeller includes a series of openings formed in the substantially peripheral region of the second disk element, between pairs of adjacent vanes, substantially at the areas subjected to the greatest axial thrust.

Description

Impeller for centrifugal pump

The present invention relates to an impeller of a centrifugal pump, and particularly relates to a type having one or more stages.

As is known, the centrifugal pump has a traditional impeller made of a pair of shaped disc-shaped bodies facing each other, so that a gap in which a series of blades are arranged to connect the two discs is formed in the body.

In the center of each impeller is a hub or an equivalent connecting device that allows the impeller to be fastened to a drive shaft that is rotated by a motor device.

Although known types of impellers have been widely used, they have disadvantages; among these disadvantages, the most significant may be the generation of axial thrust.

The impeller of a centrifugal pump actually has to withstand different pressures acting on its two sides: a pressure lower than atmospheric pressure generally acts on the intake side, while a pressure roughly equal to the transmitted pressure acts on the opposite side. This produces considerable axial thrust, which causes a significant loss of efficiency and overloads that cause damage to the motor bearings.

These problems increase significantly in the case of multi-stage pumping.

When trying to solve the problems related to axial thrust, some multi-stage pumps are manufactured The quotient protrudes half of the blade in the opposite direction of the remaining blade.

However, this solution has obvious difficulties in making internal channels.

The prior art also includes the impeller of the centrifugal pump disclosed in the Italian patent application No. VI2014A000271 filed by the same applicant. This kind of impeller effectively solves the above-mentioned problems, but it is necessary to provide dish-shaped elements with different diameters.

The purpose of the present invention is to solve the above-mentioned problems and provide an impeller of a centrifugal pump, which can reduce the axial thrust and at the same time determine the highest efficiency, and is used for disc-shaped elements with the same diameter.

Within the scope of this objective, the specific purpose of the present invention is to provide an impeller that can solve the traction problem that usually occurs on the drive shaft.

Another object of the present invention is to provide an impeller that can protect the bearing of the motor.

Another object of the present invention is to provide an impeller, which can be manufactured with a small number of components, and is therefore advantageous from a purely economical point of view.

This goal, these goals, and other goals that can be better understood from the following description are achieved by the impeller of a centrifugal pump. The impeller includes a first disc-shaped element functionally arranged toward the inlet and facing a second disc-shaped element And coaxial with it; the second disc-shaped element is rigidly connected to the first disc-shaped element with angularly spaced blades, and a fastening device is provided in the center to fasten to a drive shaft; the impeller is characterized by including forming The opening in the substantially peripheral area of the second dish-shaped element, which is between the pair of adjacent blades, is substantially in the area that bears the maximum axial thrust.

The present invention also relates to a centrifugal pump, which includes a hollow body in which at least one impeller is accommodated, which is fastened to a transmission shaft rotatable about a rotation axis; the transmission shaft is rotated by a motor device; the impeller includes A first dish-shaped element functionally arranged toward the entrance, facing and coaxial with a second dish-shaped element; the second dish-shaped element is rigidly connected to the first dish-shaped element by angularly spaced blades, and A fastening device is provided in the center to fasten to a drive shaft; the impeller is characterized by including an opening formed in the substantially peripheral area of the second dish-shaped element, which is located between pairs of adjacent blades, substantially The upper is on the area that bears the maximum axial thrust.

The impeller according to the present invention can significantly reduce the axial thrust, but at the same time determine the maximum efficiency and the head.

In fact, by emptying the area of the second dish-shaped element that bears the highest pressure, that is, by forming the openings, the forces that generate the axial thrust can be reduced.

In addition, the head and efficiency will not be reduced because the appearance of the openings is completely contained in the second dish-shaped element.

Therefore, the impeller according to the present invention solves the problem of traction usually generated on a centrifugal pump drive shaft with one or more stages. This allows, for example, to avoid damage to the motor bearings.

1‧‧‧Impeller

2‧‧‧The first dish-shaped component

3‧‧‧Second dish element

4‧‧‧Leaf

5‧‧‧Wheel

6‧‧‧Through hole

7‧‧‧Sleeve

8‧‧‧Groove

9‧‧‧Arc shape

10‧‧‧Contour appearance

101‧‧‧Impeller

110‧‧‧Profile

201‧‧‧Impeller

211‧‧‧Protrusion

301‧‧‧Impeller

308‧‧‧through hole

401‧‧‧Impeller

408‧‧‧through hole

501‧‧‧Impeller

508‧‧‧through hole

1000‧‧‧axis of rotation

From the preferred but non-exclusive specific embodiments of the impeller according to the present invention, further features and advantages can be understood by the non-limiting examples in the accompanying drawings. Among them: the first figure is a front view of an impeller according to the present invention; The second figure is a rear view of an impeller according to the present invention; the third figure is a cross-sectional view of the impeller according to the present invention; the fourth figure is a front view of an impeller according to a further specific embodiment of the present invention; the fifth figure is a fourth The rear view of the impeller in the figure; the sixth figure is a cross-sectional view of the impeller in the fourth and fifth figures; the seventh figure is a front view of an impeller according to a further specific embodiment of the present invention; the eighth figure is the seventh figure The rear view of the impeller; the ninth figure is the cross-sectional view of the impeller in the seventh and eighth figures; the tenth figure is a front view of an impeller according to a further specific embodiment of the present invention; the eleventh is the tenth figure The rear view of the impeller; the twelfth figure is the cross-sectional view of the impeller in the tenth figure and the eleventh figure; the thirteenth figure is the front view of an impeller according to a further specific embodiment of the present invention; the fourteenth figure is Figure 13 is a rear view of the impeller; Figure 15 is a cross-sectional view of the impeller in Figures 13 and 14; Figure 16 is a front view of an impeller according to a further specific embodiment of the present invention; Figure 17 is a rear view of the impeller in Figure 16; Figure 18 is a cross-sectional view of the impeller in Figures 16 and 17.

The first to third figures illustrate the impeller of a centrifugal pump according to the present invention, all designated by reference number 1.

The example exemplified in this article is about the impeller 1 used in a multi-stage centrifugal pump; however, those skilled in the art understand that the impeller according to the present invention can also be assembled in other types of pumps. on.

The multi-stage centrifugal pump, which is known and not shown in the drawings, is composed of a substantially hollow body, in which a set of impellers provided in accordance with the present invention are housed, and the impellers are coaxially fastened to a drive shaft, which is composed of A motor device rotates.

The impeller 1 includes a first dish-shaped element 2 which is functionally arranged towards the inlet, and a second dish-shaped element 3 which is functionally arranged towards the outlet.

The diameter of the second dish-shaped element 3 is substantially equal to or slightly smaller than the diameter of the first dish-shaped element 2.

The two dish-shaped elements 2 and 3 are coaxial with a rotation axis 1000 and face each other, thus forming a substantially cylindrical inner space.

The blade 4 is arranged in the internal space and rigidly connects the first dish-shaped element 2 to the second dish-shaped element 3.

The blades 4 are distributed obliquely around the rotation axis 1000, and extend from the center of the two dish-shaped elements 2 and 3 toward the peripheral area, but do not protrude outward, following an adapted appearance.

For example, in the illustrated solution, the blades 4 are bent so as to form a divergent and radially arranged pipe.

Advantageously, the second dish-shaped element 3 is fastened to a drive shaft by a fastening device. The transmission shaft, not shown in the drawing, rotates around the rotation axis 1000.

The fastening device includes a hub 5 which can be mechanically associated with the transmission shaft provided on the center of the second disc-shaped element 3.

A through hole 6 is provided in the center of the first dish-shaped element 2 relative to the hub 5; the through hole 6 has a diameter larger than the diameter of the transmission shaft.

The through hole 6 is connected to a sleeve 7 protruding from the first dish-shaped element 2.

In fact, when the impeller 1 is fixed on the transmission shaft, the sleeve 7 surrounds the transmission shaft to provide an annular opening to form the air inlet of the impeller.

According to the present invention, the impeller 1 includes a series of openings formed in the substantially peripheral area of the second disc-shaped element 3 between the pairs of adjacent blades 4, wherein the area where the disc is subjected to the maximum axial thrust can be identified.

The radial peripheral side of each opening extends a distance relative to the rotation axis 1000, and the tool is shorter than the periphery of the second dish-shaped element 3.

In other words, the openings are completely contained in the outer shape of the second dish-shaped element 3.

In the specific embodiment shown in the first to third figures, the openings are formed by the shaped grooves 8 provided in the peripheral area of the second disc-shaped element 3 between the pairs of adjacent blades 4 .

Each contour groove 8 has an arc-shaped outer shape 9 on the radial peripheral side; the arc-shaped outer shape 9 has a protrusion facing the rotation axis 1000.

The arc-shaped profile 9 is connected to a relative profile profile 10 (with a curved part in the example shown in the first to third figures), and has the protrusion facing the rotation axis 1000.

The fourth to sixth figures show an impeller, generally designated by reference number 101, which is similar to the impeller 1, but provides an outline 110 with the protrusion facing outside the second dish-shaped element 3.

According to the specific embodiment shown in the seventh to ninth figures, where the impeller according to the present invention is generally designated as the reference number 201, then the circular arc shape 9 of the contour groove 8 and the contour shape 10 or image It is a contour shape 110, which is composed of one or more radial extensions that have the function of making the structure rigid The tabs 211 are connected.

According to the specific embodiment illustrated in the tenth figure to the twelfth figure, the impeller according to the present invention is designated with reference number 301, and the openings are formed by the second disc element 3 between the pair of adjacent blades 4 A through hole 308 provided in the peripheral area is formed.

In the example shown in the tenth figure to the twelfth figure, the center of the through hole 308 is arranged substantially along a circular arc of a circle, which is centered on the rotation axis 1000; The through holes are arranged in other equivalent ways.

For example: Figures 13 to 15 show an impeller, designated by the reference number 401, similar to the impeller 301, but with through holes 408, which are essentially along a plurality of circles that are concentric and centered about the axis of rotation 1000 Arc to form.

The sixteenth to eighteenth figures show an impeller according to the present invention, designated by reference number 501, included between pairs of adjacent blades 4, substantially arranged along a circular arc centered outside the disc The through hole 508 provided in the second dish-shaped element 3.

In the specific embodiments shown in FIGS. 4 to 18, the elements corresponding to those described with reference to the specific embodiments shown in FIGS. 1 to 3 are all assigned the same reference numbers.

The impeller according to the present invention can be manufactured by many technologies using many metal materials, such as steel, stainless steel, cast steel, cast iron, copper, etc., or other materials with necessary technical characteristics, such as certain technical polymers.

In addition, please note that in any case, the structural details of the contour groove 8 and/or the through holes 308, 408 or 508 are changed in a substantially equivalent manner in terms of shape, size, ratio and configuration, but they do not deviate from The field of the invention.

Regarding the operation of the impeller according to the present invention, it can be observed from experimental tests and careful analysis of the results that the openings provided in the second dish-shaped element 3 have higher hydrodynamic efficiency and a good head for The axial thrust is reduced equally.

In practice, it can be found that the impeller used in the centrifugal pump according to the present invention can completely achieve the desired goal, because it can reduce a considerable degree of axial thrust while ensuring the highest efficiency and head.

In fact, by emptying the area of the second dish-shaped element that bears the highest pressure, that is, by forming the openings, the forces that generate the axial thrust can be reduced.

In addition, the head and efficiency will not be reduced because the appearance of the openings is completely contained in the second dish-shaped element.

Therefore, the impeller according to the present invention solves the problem of traction usually generated on a centrifugal pump drive shaft with one or more stages. This allows, for example, to avoid damage to the motor bearings.

In this way, the impeller of the centrifugal pump and the centrifugal pump are conceived to be easy to make many modifications and changes, all of which are within the scope of the concept of the present invention; all details can be further replaced by other technically equivalent elements.

In practice, as long as the material used meets the specific purpose, shape and size, any material according to the needs and technical status can be used.

This application claims the priority of the Italian patent application No. VI2015A000081 filed on March 20, 2015, which is hereby incorporated as a reference.

1‧‧‧Impeller

3‧‧‧Second dish element

5‧‧‧Wheel

8‧‧‧Forming groove

9‧‧‧Arc shape

10‧‧‧Contour appearance

Claims (7)

An impeller of a centrifugal pump, comprising a first disc-shaped element and a second disc-shaped element, the first disc-shaped element is functionally arranged toward the inlet, facing the second disc-shaped element and coaxial with it; The two disc-shaped elements are functionally arranged toward the outlet, and the blades separated by angles are rigidly connected to the first disc-shaped element, and a fastening device is provided in the center to fasten to a transmission shaft; the impeller is characterized by: The openings formed in the substantially peripheral area of the second dish-shaped element are located between the pair of adjacent blades and are substantially on the area that bears the maximum axial thrust; the openings are caused by the adjacent blades The second dish-shaped element between the pairings is formed by contour grooves formed in the substantially peripheral area; the radial peripheral side of each of the contour grooves has an arc-shaped appearance; each The iso-contour grooves all have a contour appearance relative to the arc-shaped appearance; the contour appearance has a curved part with a protrusion facing the rotation axis. For example, the impeller of item 1 of the scope of patent application, wherein the radial peripheral side of each of the openings extends a distance relative to the rotation axis of the impeller, the distance being shorter than the periphery of the second dish-shaped element. For example, the impeller of the first item in the scope of patent application, wherein the contour has a curved part with a protrusion facing the outside of the second dish-shaped element. For example, the impeller of the first item of the scope of patent application, wherein the circular arc shape and the contour shape are connected by at least one substantially radially extending protrusion. For example, the impeller of item 1 in the scope of patent application, wherein the fastening device includes a hub, which is in the machine It is mechanically associated with the transmission shaft; the hub is relative to a sleeve whose diameter is larger than the diameter of the rotation axis; and the sleeve is provided on the first dish-shaped element. For example, the impeller of item 1 in the scope of patent application, wherein the second disc-shaped element has a diameter that is substantially equal to or smaller than the diameter of the first disc-shaped element. A centrifugal pump comprising a hollow body, in which at least one impeller is accommodated. The impeller is fastened to a transmission shaft rotatable about a rotation axis; the transmission shaft is rotated by a motor device; and the impeller includes a first A disc-shaped element and a second disc-shaped element, the first disc-shaped element is functionally arranged toward the inlet, facing the second disc-shaped element and coaxial with the second disc-shaped element; the second disc-shaped element is functionally arranged facing the outlet, The blades separated by an angle are rigidly connected to the first dish-shaped element, and a fastening device is provided in the center to fasten to a drive shaft; the impeller is characterized by including: the substance formed on the second dish-shaped element The openings in the upper peripheral area, which are between the adjacent blade pairs, are substantially on the area that bears the maximum axial thrust; the openings are defined by the openings of the second dish-shaped element between adjacent blade pairs Is formed by contour grooves formed in the substantially peripheral area; the radial peripheral side of each of the contour grooves has a circular arc shape; each of the contour grooves has a contour shape, Relative to the circular arc shape; the contour shape has a curved part with a protrusion facing the rotation axis.

Images