CN214036241U - Centrifugal pump impeller - Google Patents

Abstract

The utility model discloses a centrifugal pump impeller, the blade of apron around front shroud, back shroud and the connection that sets up relatively, the blade is three along circumferencial direction evenly distributed, front shroud and back shroud are the triangle-shaped of unfilled corner in the projected appearance profile in the axial direction, and unfilled corner region position is at the blade end, and unfilled corner is circular-arcly with the impeller concentric, the blade cladding is in front shroud and back shroud. The utility model discloses because the appearance profile of front and back apron is the triangle form of unfilled corner, when the impeller was rotatory, when the blade participated in the liquid work, the apron also participated in the work to liquid, effectively eliminated the hump phenomenon of pump lift curve, and adopted three blades, alleviateed impeller finished product weight, practiced thrift the material, practiced thrift the cost. The ratio of the sum of the thicknesses of the cover plates of the front cover plate and the rear cover plate at the water outlet end of the impeller to the axial width of the water outlet end of the blade is more than or equal to 0.5, and tests show that the hump solving effect is more obvious.

Description

Centrifugal pump impeller

Technical Field

The utility model relates to a centrifugal pump impeller.

Background

The impeller is a key part of the pump, performance parameters such as flow rate, lift and the like of the pump are generated by the impeller, and the shape of a performance curve is mainly determined by the impeller. The impeller of general centrifugal pump comprises front shroud, back shroud, blade, wheel hub, and under general condition, the design has a front opening ring on the front shroud, and the design has a back opening ring on the back shroud, and the blade presss from both sides between front shroud and back shroud, and the effect that each position played is: the front opening ring, the rear opening ring and the shell are matched to form a small gap to limit the liquid backflow amount so as to prevent waste efficiency, the front cover plate, the rear cover plate and the blades jointly form a plurality of flow channels which are twisted in space and are uniformly distributed along the circumferential direction, and liquid flows from the central part of the impeller to the outer diameter under the action of centrifugal force under the rotation driving of the impeller in the flow channels, so that the flow and the lift of the pump are generated. In the operation of the impeller, the main part for applying work to the liquid is a bent and rib-shaped blade, and the front cover plate and the rear cover plate of the traditional impeller are both in a regular disc shape, so that the cover plates do not participate in applying work to the liquid in the rotation process, namely the cover plates do not generate centrifugal force to the liquid. The main geometric dimensions that affect the performance of the impeller are: the impeller outer diameter, the water outlet width b, the thickness k of the front cover plate and the rear cover plate, the number of blades and the like, wherein the size of the impeller outer diameter influences the height of a lift, the size of the water outlet width b influences the size of a flow, the size of the thickness k of the front cover plate and the rear cover plate influences the structural strength of the impeller, the number of the blades is usually between 3 and 9, and the blades are calculated and selected by a designer according to performance requirements. The conventional impeller (after being assembled into a whole pump) has a hump phenomenon with a small probability of a lift curve, and the pump with the hump phenomenon can cause instability of a pumping system in a small-flow use area, which is one of the technical problems which are not well solved in the technical field of centrifugal pumps so far.

Disclosure of Invention

The to-be-solved technical problem of the utility model is to provide an equipment can eliminate centrifugal pump lift curve hump phenomenon's centrifugal pump impeller in the pump body.

For solving the technical problem, the utility model discloses a relative front shroud, the back shroud that sets up and connect the blade of front shroud back shroud, its structural feature is the blade is three along circumferencial direction evenly distributed, front shroud and back shroud are the triangle-shaped of unfilled corner in the projected appearance profile of axial direction, and unfilled corner portion is located the blade end, and unfilled corner portion is circular-arc with the impeller concentric, the blade cladding is in front shroud and back shroud.

The blade is in the shape of a bent rib.

The ratio of the sum of the thicknesses of the cover plates of the front cover plate and the rear cover plate at the water outlet end of the impeller to the axial width of the water outlet end of the blade is more than or equal to 0.5.

After the structure is adopted, the outline of the front cover plate and the back cover plate is in the shape of the triangle with unfilled corners, when the impeller rotates, the blades participate in acting on liquid, and simultaneously, the cover plates also participate in acting on the liquid, so that the hump phenomenon of a pump lift curve is effectively eliminated, and the weight of the finished impeller is reduced, the material is saved, and the cost is saved by adopting the three blades. The ratio of the sum of the thicknesses of the cover plates of the front cover plate and the rear cover plate at the water outlet end of the impeller to the axial width of the water outlet end of the blade is more than or equal to 0.5, and the hump solving effect is more obvious.

Drawings

The following detailed description of embodiments of the present invention is provided with reference to the accompanying drawings:

FIG. 1 is a schematic longitudinal sectional view of the present invention;

fig. 2 is a schematic structural view of fig. 1 with a left side view after a front cover plate is removed.

Detailed Description

Referring to the attached drawings, the centrifugal pump impeller comprises a front cover plate 2 and a rear cover plate 4 which are oppositely arranged, blades 3 are arranged between the front cover plate 2 and the rear cover plate 4, the blades 3 are three pieces which are uniformly distributed along the circumferential direction, a front opening ring 1 is arranged on the front cover plate 2, a rear opening ring 5 is arranged on the rear cover plate 4, a hub 6 is arranged at the center of the impeller rear cover plate 5, and the blades 3 are clamped between the front cover plate 2 and the rear cover plate 4 to connect the front cover plate and the rear cover plate. The front cover plate 2 and the rear cover plate 4 are in the shape of a triangle with a notch angle in the projection in the axial direction, the notch angle part area is positioned at the tail end of the blade 3, the notch angle part is in the shape of a circular arc concentric with the impeller, and the blade 3 is covered in the front cover plate 2 and the rear cover plate 4. Each part plays the role of: the front opening ring 1 and the rear opening ring 5 are matched with the shell to form a small gap to limit the liquid backflow amount so as to prevent waste efficiency, the front cover plate 2, the rear cover plate 4 and the blades 3 jointly form a plurality of flow channels which are twisted in space and uniformly distributed along the circumferential direction, and liquid flows from the central part to the outer diameter of the impeller under the action of centrifugal force under the rotation of the impeller in the flow channels, so that the flow rate and the lift of the pump are generated. The impeller is mounted in the pump body through the hub 6 for use, that is, the centrifugal pump impeller is mounted on the pump shaft, and the structure of the pump body is a known structure and is not described in detail herein.

The main geometric dimensions that affect the performance of the impeller are: the impeller outer diameter, the water outlet width b, the thickness k of the front cover plate and the rear cover plate, the number of blades and the like, wherein the height of the lift is influenced by the size of the outer diameter of the impeller, the flow is influenced by the size of the water outlet width b, the structural strength of the impeller is influenced by the size of the thickness k of the front cover plate and the rear cover plate, and the number of blades is usually calculated and selected by a designer according to performance requirements. Referring to fig. 1, in this embodiment, the thickness of the cover plates of the front cover plate 2 and the rear cover plate 4 at the water outlet end of the impeller is k, the axial width of the water outlet end of the blade 3 (i.e., the width of the water outlet runner opening) is b, and the ratio of the sum of the thicknesses of the cover plates of the front cover plate 2 and the rear cover plate 4 at the water outlet end of the impeller to the axial width of the water outlet end of the blade 3 is greater than or equal to 0.5, i.e., (2 k/b) is greater than or equal to 0.5. Referring to fig. 2, the blades 3 are curved ribs and are uniformly distributed along the circumferential direction, two corners (the corners are two corners of the blade end formed by the blade radial rib contour line and the impeller outer circumferential line) are formed at the intersection of the blade end and the impeller outer circumference, one side is an acute angle and the other side is an obtuse angle, the contour of the front cover plate 2 and the rear cover plate 4 projected in the axial direction is in a truncated triangle shape, the truncated area is located at the blade 3 end, and the truncated portion is in an arc shape concentric with the impeller, which means that: the impeller is in a shape of three long sides and three short sides, the three long sides are linear, the three short sides are in an arc shape, one end of each linear side starts from an acute angle vertex formed by the intersection of the tail end of each blade and the outer circumference of the impeller, the other end of each linear side is stopped at one point on the outer circumference near the tail end of the adjacent blade, the point is close to an obtuse angle formed by the intersection of the tail end of each blade and the outer circumference of the impeller, and the connecting line of the two points is tangent to the arc-shaped contour line of the adjacent blade; after the three straight lines are established, the outer circumference is cut off as three chords of the excircle of the impeller, the remaining three sections of shorter arcs become three short sides of the front cover plate and the rear cover plate, the blades 3 are coated in the front cover plate 2 and the rear cover plate 4, the overall outline of the impeller is approximately in a triangle shape with unfilled corners, and the dotted line in the figure is the rotating trajectory of the impeller.

The utility model discloses the appearance profile of front and back apron is the triangle form of unfilled corner, adopts non-discoid apron promptly, and during the impeller was rotatory, when the blade participated in the liquid work, the apron also participated in the work to liquid, effectively eliminated the hump phenomenon of pump lift curve, eliminated the hump phenomenon of centrifugal pump lift curve promptly, made the pump lift curve of centrifugal pump become one "zero" flow point lift the highest, then along with the flow increase, the curve that descends gradually. And three blades are adopted, so that the weight of the finished impeller is reduced, the material is saved and the cost is saved compared with a disc-shaped cover plate. The ratio of the sum of the thicknesses of the cover plates of the front cover plate and the rear cover plate at the water outlet end of the impeller to the axial width of the water outlet end of the blade is more than or equal to 0.5, and tests show that the hump solving effect is more obvious.

Claims (3)

1. The utility model provides a centrifugal pump impeller, includes relative front shroud (2), back shroud (4) that set up and connects front and back blade (3) of apron, characterized by blade (3) are three along circumferencial direction evenly distributed, front shroud (2) and back shroud (4) are the triangle-shaped of unfilled corner in the projected appearance profile of axial direction, and unfilled corner portion region is located blade (3) end, and unfilled corner portion is circular-arc with the impeller concentric, blade (3) cladding is in front shroud (2) and back shroud (4).

2. A centrifugal pump impeller according to claim 1, characterized in that the blades (3) are shaped as curved ribs.

3. The centrifugal pump impeller as claimed in claim 1 or 2, wherein the ratio of the sum of the cover plate thicknesses of the front cover plate (2) and the rear cover plate (4) at the water outlet end of the impeller to the axial width of the water outlet end of the blade (3) is not less than 0.5.

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