CN213116848U - Cantilever type axial fan structure - Google Patents

Abstract

A cantilever type axial flow fan structure comprises a hub, wherein a plurality of blades are arranged on one side of the hub and are distributed uniformly in a hub ring shape, trailing edge molded lines are arranged on the blades and at least take a concave-convex variable cross section form, the variable cross section form comprises a root area, a middle area and an outer edge area, the root area, the middle area and the outer edge area are in transition connection through arcs, at least more than two blades are arranged, the root areas of two adjacent blades are connected with each other, and the adjacent blades form a connection molded line; abrupt transition connection between the front edge of the blade and the hub molded line and between the tail edge of the blade and the hub molded line is avoided, and stress concentration is reduced; the phenomena of uneven fluid flow near the hub and backflow and turbulence at the root of the axial flow blade are avoided, the working efficiency of the axial flow blade is improved, and the noise is reduced; the weight reducing effect is achieved on the premise that the mechanical property and the pneumatic property of the axial flow fan are not reduced. The utility model has the characteristics of simple structure is reasonable, reduce stress concentration, wind-force is even, easy production, easy realization and safe and reliable etc.

Description

Cantilever type axial fan structure

Technical Field

The utility model relates to a fan structure, in particular to cantilever type axial fan structure.

Background

The fan blades of the existing fan generally have the defects of small air volume, low efficiency, high noise and the like, and the axial flow fan with a small hub ratio is required in the application occasions of the axial flow fan with low rotating speed, large air volume and low pressure head. However, the hub of the conventional axial flow fan is large in size, and the hub is large, and if a structure with a small hub ratio is adopted, the root strength of the axial flow blade cannot be guaranteed.

As shown in fig. 4, 5, and 6, 1 ' is a blade trailing edge, 2 ' is a hub reinforcing rib, 3 ' is a shaft hole, 4 ' is a stress concentration region, and 5 ' is a leading edge, the hub of the conventional axial flow fan is a cylindrical structure, and the cylindrical structure must be made large enough to ensure that the root of the axial flow blade is connected to the hub at a fixed installation angle. Because the hub area of the axial flow blade does not work, the structure not only increases the size and the weight of the hub 5', but also causes uneven flow of fluid near the hub, root backflow and turbulence can be formed, the work efficiency of the axial flow blade is reduced, and noise is increased.

Secondly, because there is an abrupt structure in the transition between the hub profile of the conventional axial fan and the leading edge profile 5 ' and the trailing edge profile 1 ' of the axial fan, the abrupt structure is the stress concentration region 4 ' of the axial fan, as shown in fig. 6.

Chinese patent document No. CN102374194A discloses an axial flow wind wheel in 11/10/2011, which specifically discloses an axial flow wind wheel including more than two blades arranged on a hub, wherein the blades are distributed on the hub at equal intervals or unequal intervals with the central axis of rotation of the wind wheel as the center, the outer edge of each blade is in a wave-shaped space curve, and the wave shape of the outer edge of each blade enables gas on the pressure surface of each blade to flow into the suction surface through the outer edge of each wave-shaped blade to different degrees, thereby changing the pressure distribution of the blade. However, if the axial flow wind wheel adopts a small hub ratio structure, the root strength of the axial flow blades cannot be ensured, so that the wind wheel is easy to break or tear during operation.

Therefore, further improvements are desired.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a simple structure is reasonable, reduce stress concentration, material cost low, wind-force is even, easy production, easy realization and safe and reliable, effectively improves axial compressor blade's acting efficiency to reduce the cantilever type axial fan structure of noise, in order to overcome the weak point among the prior art.

According to a cantilever type axial fan structure of this purpose design, including wheel hub, its characterized in that: the novel hub is characterized in that a plurality of blades are arranged on one side of the hub and are uniformly distributed in an annular manner, trailing edge molded lines are arranged on the blades, and the trailing edge molded lines are at least in a concave-convex variable cross-section form.

The variable cross-sectional form includes a root region, a middle region, and an outer edge region; the root area and the middle area, and the middle area and the outer edge area are in transition connection through arcs.

The blade is provided with more than two at least, and two adjacent blade root regions are connected with each other and form a connecting molded line.

The connecting line is C-shaped.

The root area and the middle area are in straight-line smooth connection.

The middle area and the outer edge area are in wave-shaped, fold-line-shaped or arc-shaped smooth connection.

The utility model discloses a cantilever type axial fan structure beneficial effect as follows:

a. the blade is provided with a trailing edge molded line which is at least in a concave-convex variable cross section form, so that the superposition of vortex shedding frequency is reduced, and the noise reduction effect is achieved; the weight reducing effect is achieved on the premise that the mechanical property and the pneumatic property of the axial flow fan are not reduced.

b. The variable cross-section form comprises a root region, a middle region and an outer edge region; the root area and the middle area, and the middle area and the outer edge area are in transition connection through arcs.

c. The root areas of two adjacent blades are mutually connected and form a connecting molded line, so that the stress concentration area generated by the molded line of the front edge of each blade is avoided on the premise of ensuring the acting efficiency of the axial flow blade.

d. Abrupt transition connection between the front edge of the blade and the molded line of the hub and between the tail edge of the blade and the molded line of the hub is avoided, and stress concentration is reduced.

e. The phenomena of uneven fluid flow near the hub and backflow and turbulence at the root of the axial flow blade are avoided, the work efficiency of the axial flow blade is improved, and the noise is reduced.

In summary, the axial flow blade has the characteristics of simple and reasonable structure, stress concentration reduction, low material cost, uniform wind power, easy production, easy realization, safety, reliability, effective improvement on the acting efficiency of the axial flow blade and the like.

Drawings

Fig. 1 is a schematic structural view (front view) of an axial fan according to an embodiment of the present invention.

Fig. 2 is a schematic structural view (back side) of an axial fan according to an embodiment of the present invention.

Fig. 3 is a schematic view of another view angle structure of an axial fan according to an embodiment of the present invention.

Fig. 4 is a schematic structural view (front side) of a prior art axial flow fan.

Fig. 5 is a schematic view (back side) of a prior art axial fan.

Fig. 6 is a prior art stress distribution diagram for a conventional axial fan.

In the figure, 1 is a root region, 2 is a middle region, 3 is an outer edge region, 4 is a front edge connecting molded line, 5 is a connecting molded line, 6 is a tail edge middle region molded line, 7 is a wave shape, 8 is a hub, 9 is a straight line shape, 10 is a front edge molded line, 1 ' is a blade tail edge, 2 ' is a hub reinforcing rib, 3 ' is a shaft hole, 4 ' is a stress concentration region, and 5 ' is a front edge.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and examples.

Referring to fig. 1-3, the wheel cover molded line structure of the backward inclined fan comprises a hub 8, wherein a plurality of blades are arranged on one side of the hub 8 and are uniformly distributed in an annular manner by the hub 8, trailing edge molded lines 11 are arranged on the blades, and the trailing edge molded lines 11 are at least in a concave-convex variable cross-section form; the superposition of vortex shedding frequency is reduced, and the noise reduction effect is achieved; the weight reducing effect is achieved on the premise that the mechanical property and the pneumatic property of the axial flow fan are not reduced.

Further, with reference to fig. 1, the variable cross-sectional form comprises a root region 1, a middle region 2 and an outer edge region 3; the root region 1 and the middle region 2, and the middle region 2 and the outer edge region 3 are in transition connection through arcs; the phenomena of uneven fluid flow near the hub and backflow and turbulence at the root of the axial flow blade are avoided, the working efficiency of the axial flow blade is improved, and the noise is reduced; on the premise of ensuring the working efficiency of the axial flow blade, the stress concentration area generated by the molded line of the front edge of the blade is avoided.

Furthermore, a trailing edge middle region profile 6 is provided on the middle region 2.

Further, the connecting profile 5 is connected with the leading edge connecting profile 4 on the leading edge profile 10.

Further, referring to fig. 2, at least two blades are provided, and the root regions 1 of two adjacent blades are connected with each other to form a connecting profile 5; the weight reducing effect is achieved on the premise that the mechanical property and the pneumatic property of the axial flow fan are not reduced.

Further, the connecting profile 5 and the leading edge connecting profile 4 are connected in a C-shape.

Further, referring to fig. 1, a smooth connection in a line shape 9 is provided between the root region 1 and the middle region 2; a wave-shaped 7, fold line-shaped or circular arc-shaped smooth connection is arranged between the middle area 2 and the outer edge area 3; the superposition of vortex shedding frequency is reduced, and the noise reduction effect is achieved.

The foregoing is a preferred embodiment of the present invention showing and describing the basic principles, main features and advantages of the present invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are intended to illustrate the principles of the invention, and that various changes and modifications may be made without departing from the spirit and scope of the invention, all of which are intended to be covered by the appended claims. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims (6)

1. A cantilever type axial fan structure, includes wheel hub (8), its characterized in that: a plurality of blades are arranged on one side of the hub (8) and are distributed in an annular and uniform mode through the hub (8), trailing edge molded lines (11) are arranged on the blades, and the trailing edge molded lines (11) are at least in a concave-convex variable cross section mode.

2. The cantilevered axial fan structure according to claim 1, wherein: the variable cross-section form comprises a root region (1), a middle region (2) and an outer edge region (3); the root region (1) is in transition connection with the middle region (2) and the middle region (2) is in transition connection with the outer edge region (3) through arcs.

3. The cantilevered axial fan structure according to claim 2, wherein: the blade is provided with more than two at least, and the root areas (1) of two adjacent blades are connected with each other and form a connecting molded line (5).

4. The cantilevered axial fan structure according to claim 3, wherein: the connecting line (5) is C-shaped.

5. The cantilevered axial fan structure according to claim 2, wherein: the root area (1) and the middle area (2) are smoothly connected in a straight line shape (9).

6. The cantilevered axial fan structure according to claim 2, wherein: the middle area (2) and the outer edge area (3) are smoothly connected in a wavy shape (7), a fold line shape or a circular arc shape.

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