阅读说明：本技术 风扇及轴流叶轮 (Fan and axial flow impeller ) 是由 梁浩 柳洲 陈宇强 林海利 于 2019-09-30 设计创作，主要内容包括：本发明涉及一种风扇及轴流叶轮。轴流叶轮包括第一风叶,第一风叶包括多个第一叶片及第一轮毂,多个第一叶片间隔设置于第一轮毂上。第一叶片包括第一叶根与第一叶顶,其中,第一叶根为第一叶片与第一轮毂相接触的部分,第一叶顶为远离第一叶根的部分。第一叶顶向远离第一叶顶的弦线的方向弯曲设置,以使第一叶片的压力面位于第一叶顶的部分为内凹面,能够提高第一叶片的压力面的做功效率,在保证第一叶片做功的同时,降低风对第一叶片的负载,使得第一风叶的功率降低,进而降低轴流叶轮的功率,使得风扇更加节能。同时,第一叶根平滑过渡至第一叶顶,能够有效提高第一叶片导风的流畅性,提高送风的舒适度。(The present invention relates to a fan and an axial flow impeller. The axial flow impeller comprises a first fan blade, the first fan blade comprises a plurality of first blades and a first hub, and the plurality of first blades are arranged on the first hub at intervals. The first blade comprises a first blade root and a first blade top, wherein the first blade root is a part of the first blade, which is contacted with the first hub, and the first blade top is a part far away from the first blade root. The first blade top is arranged in a bending mode towards the direction of the chord line far away from the first blade top, so that the part, located on the first blade top, of the pressure surface of the first blade is an inner concave surface, the work doing efficiency of the pressure surface of the first blade can be improved, the work doing of the first blade is guaranteed, meanwhile, the load of wind on the first blade is reduced, the power of the first fan blade is reduced, the power of the axial flow impeller is further reduced, and the fan is more energy-saving. Meanwhile, the first blade root is in smooth transition to the first blade top, so that the fluency of air guiding of the first blade can be effectively improved, and the comfort level of air supply is improved.)

1. The axial flow impeller is characterized by comprising a first fan blade, wherein the first fan blade comprises a plurality of first blades and a first hub, and the first blades are arranged on the first hub at intervals; the first blade comprises a first blade root and a first blade top, the first blade root is a part of the first blade, which is contacted with the first hub, the first blade top is a part of the first blade, which is far away from the first blade root, a connecting line between two opposite ends of the first blade top is a chord line of the first blade top, the first blade top is arranged in a bending way towards the direction of the chord line far away from the first blade top, so that the part, which is positioned on the first blade top, of a pressure surface of the first blade is a blade root inner concave surface, and the first blade top is in smooth transition to the first blade top.

2. The axial flow impeller of claim 1, wherein the first blades define a first tip and a first tail proximate opposite ends of the first tip portion, respectively, the first tip having a fillet dimension of R1 and the first tail having a fillet dimension of R2, wherein R2> R1.

3. The axial-flow impeller of claim 2, wherein the fillet dimension R1 of the first tip outer edge is 2mm to 8 mm; and/or

The fillet size R2 of the outer edge of the first blade tail is 30-50 mm.

4. The axial-flow impeller according to claim 2 or 3, characterized in that the first blade tail is curved in the direction of the pressure face of the first blade forming a sweep.

5. The axial-flow impeller according to claim 4, characterized in that the angle β between the swept-down portion and the tangential plane of the first blade tip is between 0 ° and 15 °.

6. The axial flow impeller according to any one of claims 1 to 3, wherein a maximum distance between the first tip and the first tip chord line is a, and a chord length of the first tip chord line is L2, wherein a/L2 is 0.03-0.06.

7. The axial flow impeller of claim 6, wherein the mounting angle of the first blade root with respect to the axis of the first hub is α 1 and the mounting angle of the first blade tip with respect to the axis of the first hub is α 2, wherein α 2> α 1.

8. The axial-flow impeller according to claim 7, characterized in that the mounting angle α 1 of the first blade root with respect to the axis of the first hub is 40 ° to 60 °; and/or

The installation angle alpha 2 of the first blade top relative to the axis of the first hub is 60-75 degrees.

9. The axial flow impeller according to any one of claims 1 to 3, wherein a line connecting opposite ends of said first blade root is a chord line of said first blade root, said chord line of said first blade root has a chord length of L1, said chord line of said first tip has a chord length of L2, wherein L2> L1.

10. The axial flow impeller according to claim 7, wherein said first root chord length L1 is 40mm to 60 mm; and/or

The chord length L2 of the first blade top chord line is 60 mm-80 mm.

11. The axial-flow impeller according to any one of claims 1 to 3, further comprising second blades, wherein an inner wall of the first hub defines a mounting cavity, and the second blades are disposed in the mounting cavity.

12. The axial-flow impeller according to claim 11, wherein the second fan blade includes a plurality of second blades and a second hub, and the plurality of second blades are disposed on the second hub at intervals;

wherein the ratio of the diameter D1 of the second hub to the outer diameter D2 of the second blade is 0.2-0.3; and/or the ratio of the outer diameter D2 of the second blade to the outer diameter D3 of the first blade is 0.5-0.7.

13. The axial flow impeller of claim 12, wherein a portion of the second blade in contact with the second hub forms a second blade root, the second blade further having a second blade tip, the second blade tip being a portion distal from the second blade root, the second blade root having a mounting angle α 3 with respect to an axis of the second hub, the second blade tip having a mounting angle α 4 with respect to the axis of the second hub, wherein α 4> α 3.

14. The axial-flow impeller according to claim 13, characterized in that the mounting angle α 3 of the second blade root with respect to the axis of the second hub is 30 ° to 50 °; and/or

The installation angle alpha 4 of the second blade top relative to the axis of the second hub is 60-75 degrees.

15. The axial flow impeller of claim 13, wherein a line connecting opposite ends of said second blade root is a chord line of said second blade root having a chord length of L3, a line connecting opposite ends of said second blade tip is a chord line of said second blade tip having a chord length of L4, wherein L4> L3.

16. The axial flow impeller of claim 15, wherein said second root chord has a chord length L3 of 20mm to 40 mm; and/or

The chord length L4 of the second blade top chord line is 50 mm-70 mm.

17. The axial-flow impeller of claim 11, wherein the first fan blade and the second fan blade are of an integrally formed structure.

18. A fan, comprising:

an axial flow impeller according to any one of claims 1 to 17; and

and the rotating piece is used for driving the axial flow impeller to rotate.

Technical Field

The invention relates to the technical field of fans, in particular to a fan and an axial flow impeller.

Background

At present, the conventional axial flow fan generally adopts three blades, five blades, seven blades and other blades to realize air supply. If the working of the axial flow fan is ensured, the working area of the blades of the fan blades is increased to be large, so that the load is heavy, the power is high, and the energy is not saved.

Disclosure of Invention

In view of the above, it is desirable to provide a fan and an axial flow impeller that can ensure work performance and avoid increasing power consumption.

An axial flow impeller comprises a first fan blade, wherein the first fan blade comprises a plurality of first blades and a first hub, and the first blades are arranged on the first hub at intervals; the first blade comprises a first blade root and a first blade top, the first blade root is a part of the first blade, which is contacted with the first hub, the first blade top is a part of the first blade, which is far away from the first blade root, a connecting line between two opposite ends of the first blade top is a chord line of the first blade top, the first blade top is arranged in a bending way towards the direction of the chord line far away from the first blade top, so that the part, which is positioned on the first blade top, of a pressure surface of the first blade is a blade root inner concave surface, and the first blade top is in smooth transition to the first blade top.

When the axial flow impeller is used, the plurality of first blades are arranged on the first hub at intervals. The first blade comprises a first blade root and a first blade top, wherein the first blade root is a part of the first blade, which is contacted with the first hub, and the first blade top is a part far away from the first blade root. The first blade top is bent towards the direction of the chord line far away from the first blade top, so that the part, located on the first blade top, of the pressure surface of the first blade is an inward concave surface, and the work doing efficiency of the pressure surface of the first blade can be improved. When the first blade does work, the load of wind on the first blade is reduced, so that the power of the first fan blade is reduced, and the power of the axial flow impeller is further reduced. Meanwhile, the first blade root is in smooth transition to the first blade top, so that the fluency of air guiding of the first blade can be effectively improved, and the comfort level of air supply is improved.

In one embodiment, the first blade forms a first tip and a first tail near opposite ends of the first tip portion, the first tip outer edge has a fillet size of R1, and the first tail outer edge has a fillet size of R2, wherein R2> R1.

In one embodiment, the fillet dimension R1 of the outer edge of the first blade tip is 2mm to 8 mm; and/or

The fillet size R2 of the outer edge of the first blade tail is 30-50 mm.

In one embodiment, the first blade tail is curved in the direction of the pressure surface of the first blade to form a sweep.

In one embodiment, the angle β between the swept portion and the tangent plane to the first lobe apex is between 0 ° and 15 °.

In one embodiment, the maximum distance between the first blade tip and the first blade tip chord line is a, and the chord length of the first blade tip chord line is L2, wherein a/L2 is 0.03-0.06.

In one embodiment, the first blade root has an installation angle α 1 with respect to the axis of the first hub and the first blade tip has an installation angle α 2 with respect to the axis of the first hub, where α 2> α 1.

In one embodiment the first blade root has a mounting angle α 1 of 40 ° to 60 ° relative to the axis of the first hub; and/or

The installation angle alpha 2 of the first blade top relative to the axis of the first hub is 60-75 degrees.

In one embodiment, a line connecting two opposite ends of the first blade root is a first blade root chord line, the chord length of the first blade root chord line is L1, the chord length of the first blade tip chord line is L2, wherein L2> L1.

In one embodiment, the chord length L1 of the first root is 40 mm-60 mm; and/or

The chord length L2 of the first blade top chord line is 60 mm-80 mm.

In one embodiment, the fan further comprises a second fan blade, the inner wall of the first hub encloses a mounting cavity, and the second fan blade is arranged in the mounting cavity.

In one embodiment, the second fan blade includes a plurality of second blades and a second hub, and the plurality of second blades are arranged on the second hub at intervals;

wherein the ratio of the diameter D1 of the second hub to the outer diameter D2 of the second blade is 0.2-0.3; and/or the ratio of the outer diameter D2 of the second blade to the outer diameter D3 of the first blade is 0.5-0.7.

In one embodiment, the portion of the second blade in contact with the second hub forms a second blade root, the second blade further has a second blade tip, the second blade tip is a portion away from the second blade root, the installation angle of the second blade root with respect to the axis of the second hub is α 3, and the installation angle of the second blade tip with respect to the axis of the second hub is α 4, where α 4> α 3.

In one embodiment, the installation angle α 3 of the second blade root relative to the axis of the second hub is 30 ° to 50 °; and/or

The installation angle alpha 4 of the second blade top relative to the axis of the second hub is 60-75 degrees.

In one embodiment, a line connecting opposite ends of the second blade root is a chord line of the second blade root, a chord length of the second blade root chord line is L3, a line connecting opposite ends of the second blade tip is a chord line of the second blade tip, and a chord length of the second blade tip chord line is L4, wherein L4> L3.

In one embodiment, the chord length L3 of the second root is 20 mm-40 mm; and/or

The chord length L4 of the second blade top chord line is 50 mm-70 mm.

In one embodiment, the first fan blade and the second fan blade are of an integrally formed structure.

A fan, comprising:

an axial flow impeller as described above; and

and the rotating piece is used for driving the axial flow impeller to rotate.

When the fan is used, the first blades are arranged on the first hub at intervals. The axial flow impeller is driven to rotate by the rotating piece, so that air supply of the fan is realized. The first blade comprises a first blade root and a first blade top, the first blade root is a part of the first blade, which is in contact with the first hub, and the first blade top is a part far away from the first blade root. The first blade top is bent towards the direction of the chord line far away from the first blade top, so that the part, located on the first blade top, of the pressure surface of the first blade is an inward concave surface, and the work doing efficiency of the pressure surface of the first blade can be improved. When the first blade does work, the load of wind on the first blade is reduced, so that the power of the first fan blade is reduced, the power of the axial flow impeller is reduced, and the fan is more energy-saving. Meanwhile, the first blade root is in smooth transition to the first blade top, so that the fluency of air guiding of the first blade can be effectively improved, and the comfort level of air supply of the fan is improved.

Drawings

FIG. 1 is a front view of an axial flow impeller in one embodiment;

FIG. 2 is a side view of the axial flow impeller shown in FIG. 1;

FIG. 3 is an enlarged view taken at A in FIG. 2;

fig. 4 is a front view of a second fan blade in fig. 1;

fig. 5 is a side view of the second fan blade shown in fig. 4;

FIG. 6 is a velocity cloud for the axial flow impeller shown in FIG. 1.

Description of reference numerals:

10. the axial-flow impeller comprises a 100, a first fan blade, 110, a first blade, 111, a pressure surface, 112, a first blade root, 114, a first blade top, 115, a first blade tip, 116, a first blade tail, 118, a swept portion, 120, a first hub, 200, a second fan blade, 210, a second blade, 212, a second blade root, 220, a second hub, 300, a mounting piece, 310, a matching portion, 320 and a connecting portion.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, but rather should be construed as broadly as the present invention is capable of modification in various respects, all without departing from the spirit and scope of the present invention.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only and do not denote a single embodiment.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

Further, it is to be understood that, in the present embodiment, the positional relationships indicated by the terms "lower", "upper", "front", "rear", "left", "right", "inner", "outer", "top", "bottom", "one side", "the other side", "one end", "the other end", and the like are based on the positional relationships shown in the drawings; the terms "first," "second," and the like are used herein to distinguish one structural element from another. These terms are merely for convenience in describing the present invention and for simplicity in description, and are not to be construed as limiting the present invention.

Referring to fig. 1 and 2, in an embodiment, the axial flow impeller 10 can at least ensure work under the condition of reducing power, and ensure the air supply amount and the air supply range, so that the axial flow impeller 10 is more energy-saving.

Specifically, the axial flow impeller 10 includes a first blade 100, the first blade 100 includes a plurality of first blades 110 and a first hub 120, and the plurality of first blades 110 are disposed on the first hub 120 at intervals; the first blade 110 includes a first blade root 112 and a first blade tip 114, the first blade root 112 is a portion of the first blade 110 contacting the first hub 120, the first blade tip 114 is a portion of the first blade 110 away from the first blade root 112, a connecting line between two opposite ends of the first blade tip 114 is a chord line of the first blade tip 114, the first blade tip 114 is curved in a direction away from the chord line of the first blade tip 114, so that the portion of the pressure surface 111 of the first blade 110 located at the first blade tip 114 is an inner concave surface, and the first blade root 112 smoothly transitions to the first blade tip 114. The pressure surface 111 of the first blade 110 is a surface facing the rotation direction of the first fan blade 100.

In the axial flow impeller 10, the first blades 110 are provided on the first hub 120 at intervals during use. The first blade 110 includes a first blade root 112 and a first blade tip 114, wherein the first blade root 112 is a portion of the first blade 110 contacting the first hub 120, and the first blade tip 114 is a portion away from the first blade root 112. The first blade tip 114 is curved in a direction away from a chord line of the first blade tip 114, so that a portion of the pressure surface 111 of the first blade 110, which is located on the first blade tip 114, is an inner concave surface, work efficiency of the pressure surface 111 of the first blade 110 can be improved, the load of wind on the first blade 110 can be reduced while work of the first blade 110 is guaranteed, power of the first blade 100 is reduced, and power of the axial-flow impeller 10 is reduced. Meanwhile, the first blade root 112 is smoothly transited to the first blade tip 114, so that the fluency of air guiding of the first blade 110 can be effectively improved, and the comfort level of air supply is improved.

Referring to fig. 3, in one embodiment, a line connecting two opposite ends of the first blade root 112 is a chord line of the first blade root 112, and the first blade root 112 is curved away from the chord line of the first blade root 112. Wherein the camber of the first blade root 112 may be the same as or different from the camber of the first blade tip 114, and the first blade root 112 smoothly transitions to the first blade tip 114. In another embodiment, the first root 112 may also be non-curved, with the first root 112 smoothly transitioning to the first tip 114.

In one embodiment, the maximum distance between the chord lines of the first blade tip 114 and the first blade tip 114 is a, and the chord length of the chord line of the first blade tip 114 is L2, wherein a/L2 is 0.03-0.06. When the a/L2 is within the range of 0.03-0.06, the load of the first blade 110 can be reduced on the basis of ensuring the first blade 110 to do work, so that the power of the first fan blade 100 is reduced, and the first fan blade 100 is more energy-saving in the using process. At the same rotation speed, if the first blade tip 114 is not bent, the load of the first blade 110 is increased, and further the power of the first fan blade 100 is increased, and the aerodynamic efficiency of the blade is low; if the curvature of the second blade tip is too large, the work efficiency of the first blade 110 is low, and the air volume is reduced, so that the efficiency of the first fan blade 100 is reduced. In particular, the ratio of a/L2 may be 0.03, 0.04, 0.05, or 0.06.

Referring to fig. 1, in an embodiment, a first blade tip 115 and a first blade tail 116 are respectively formed at two opposite ends of a portion of the first blade 110 close to the first blade tip 114, a fillet size of an outer edge of the first blade tip 115 is R1, and a fillet size of an outer edge of the first blade tail 116 is R2, where R2> R1. The outer edge of the first blade tip 115 is set to be a smaller rounded corner, and the first blade tip 115 is located at the front edge of the first blade 110, so that the impact of the first blade tip 115 on the entering airflow can be reduced, the vortex of the first blade tip 115 is reduced, and the generation of noise is reduced. And the outer fringe of first leaf tail 116 sets up to great fillet, can weaken the falling of the wake vortex that is located first leaf tail 116 department through great fillet design, and then weakens the influence that the wake vortex flows to first leaf tail 116 department air current, can further noise reduction, improves tone quality.

Optionally, the fillet dimension R1 of the outer edge of the first blade tip 115 is 2mm to 8mm, which effectively reduces the vortex of the first blade tip 115, and further effectively reduces the noise. Specifically, the fillet dimension R1 at the outer edge of the first blade tip 115 may be 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, or the like. Further, the fillet dimension R1 of the outer edge of the first blade tip 115 may also be adjusted according to the overall size of the first blade 110. For example, when the size of the first blade 110 is larger, the fillet size of the first blade tip 115 may be selected to be larger.

Optionally, the fillet dimension R2 of the outer edge of the first blade tail 116 is 30mm to 50mm, which effectively reduces the shedding of the wake vortex and further reduces the noise. Specifically, the fillet dimension R2 at the outer edge of the first blade tail 116 may be 30mm, 40mm, 50mm, or the like. Further, the fillet dimension R2 of the outer edge of the first blade tail 116 may also be adjusted according to the overall size of the first blade 110. For example, when the size of the first blade 110 is larger, a larger fillet size of the first blade tail 116 may be selected.

Referring to fig. 3, in an embodiment, the first blade tail 116 is bent toward the pressure surface 111 of the first blade 110 to form a swept portion 118, so as to further reduce falling off of the wake vortex, increase work of the swept portion 118, and further increase air volume. Meanwhile, the curved portion 118 can diffuse the airflow on the first blade 110 when flowing out, thereby increasing the air supply range. The swept portion 118 can also effectively reduce interference between the fluid at the first blade tail 116 and the fluid at the first blade tip 115 of the adjacent first blade 110, so as to avoid formation of aerodynamic noise due to turbulent flow.

In one embodiment, the sweep 118 is angled between 0 and 15 with respect to the tangent plane to the first lobe tip 114. The air quantity can be guaranteed to be improved, and meanwhile, the power is prevented from being obviously increased. In particular, the angle β between the sweep 118 and the tangent plane to the first lobe apex 114 may be 0 °, 5 °, 10 °, or 15 °. Wherein, the tangent plane of the first leaf top 114 is the tangent plane of the most curved point of the first leaf top 114.

In one embodiment, the height between the sweep 118 and the first root 112 is approximately one-third of the distance between the first root 112 and the first tip 114. Thereby avoiding the swept portion 118 being too large to affect the energy efficiency ratio of the work done by the first blade 110.

In one embodiment, the first blade root 112 has an installation angle α 1 with respect to the axis of the first hub 120, and the first blade tip 114 has an installation angle α 2 with respect to the axis of the first hub 120, where α 2> α 1, which can ensure the work of the first blade 110. If α 2< α 1, the power of the first blade 110 is increased, and the work effect is poor, thereby decreasing the working efficiency of the first blade 110. At the same time, the load on the first blade 110 is increased, and the first blade 110 is easily deformed, which affects the service life and the service stability of the axial-flow impeller 10.

Optionally, the installation angle α 1 of the first blade root 112 with respect to the axis of the first hub 120 is 40 ° to 60 °, so that work of the first blade 110 can be guaranteed, and increase of power is avoided. Specifically, the installation angle α 1 may be 40 °, 45 °, 50 °, 55 °, or 60 °.

Optionally, the installation angle α 2 of the first blade tip 114 with respect to the axis of the first hub 120 is 60 ° to 75 °, which can ensure the work of the first blade 110 and avoid the increase of power. In particular, the mounting angle α 2 may be 60 °, 65 °, 70 °, or 75 °.

In one embodiment, the chord length of the first root 112 is L1, and the chord length of the first tip 114 is L2, wherein L2> L1. The work of the first blade 110 can be further ensured by setting L2> L1, and the increase of power is avoided.

Optionally, the chord length L1 of the chord line of the first blade root 112 is 40mm to 60mm, so that the working area of the first blade 110 can be effectively ensured, and the influence on the air distribution volume of the first blade 110 is avoided.

Optionally, the chord length L2 of the chord line of the first blade tip 114 is 60mm to 80mm, which can further effectively ensure the working area of the first blade 110 and avoid affecting the air volume of the first blade 110. In other embodiments, the chord length L1 of the first blade root 112 and the chord length L2 of the first tip 114 may also be increased as appropriate for increasing the overall size of the first blade 110 or decreased as appropriate for decreasing the overall size of the first blade 110.

Referring to fig. 1 and 4, in an embodiment, the axial-flow impeller 10 further includes a second blade 200, an inner wall of the first hub 120 defines a mounting cavity, and the second blade 200 is disposed in the mounting cavity. On one hand, the structure of the first fan blade 100 can be further strengthened by arranging the second fan blade 200, so that the structure of the axial flow impeller 10 is more stable. On the other hand, the air volume and the air blowing range of the axial flow impeller 10 can be further increased by providing the second fan blades 200.

Specifically, the second fan blade 200 includes a plurality of second blades 210 and a second hub 220, and the plurality of second blades 210 are disposed on the second hub 220 at intervals. The second hub 220 drives the second blade 210 to rotate, so as to realize air supply of the second fan blade 200.

In this embodiment, the first blade 100 and the second blade 200 are integrally formed. Further, a side of the second blade 210 away from the second hub 220 is fixed on the first hub 120, wherein the second hub 220 is used for connecting a rotating component. When the second fan blade 200 rotates, the first fan blade 100 can be further driven to rotate, and the first fan blade 100 and the second fan blade 200 can rotate simultaneously. Specifically, the first blade 100 and the second blade 200 are integrally injection molded, so that the axial flow impeller 10 is more stable in structure.

In the present embodiment, the number of the first blades 110 is greater than or equal to the number of the second blades 210. Since the energy efficiency ratio of the first fan blade 100 is greater than that of the second fan blade 200, the number of the first blades 110 is set to be greater than or equal to that of the second blades 210, the energy efficiency ratio of the overall work of the axial flow impeller 10 can be effectively improved, and the power consumption is reduced.

Specifically, the number of the first blades 110 and the second blades 210 is odd. Further, the blades are prevented from being symmetrically arranged, so that the axial flow impeller 10 is easily deformed due to the symmetric distribution of centrifugal force, wind resistance and the like on the first blade 110 and the second blade 210 in the rotating process, and the forces in different directions can be mutually offset by adopting the asymmetric distribution, so that the stress deformation on the first fan blade 100 and the second fan blade 200 is reduced.

In the present embodiment, the number of the first blades 110 is seven. The number of the second blades 210 is five. Of course, the number of the first blades 110 may also be three, five, nine, etc. The number of second blades 210 may also be three, seven, etc. other numbers.

Referring to fig. 1 again, in the present embodiment, the ratio of the outer diameter D2 of the second blade 210 to the outer diameter D3 of the first blade 110 is 0.5-0.7. The second fan blade 200 of the axial-flow impeller 10 is a main working component, and the second fan blade 200 performs relatively less work. By controlling the ratio of the outer diameters of the second blade 210 and the first blade 110, the working areas of the second blade 210 and the first blade 110 can be controlled. Generally, if the ratio of D2/D3 is larger, i.e. the outer diameter of the second blade 210 is larger, the working area of the first blade 110 will be reduced. If the ratio D2/D3 is small, the outer diameter of the second blade 210 is small, and the working area of the first blade 110 is large, but the overall power of the axial-flow impeller 10 is increased. The D2/D3 is controlled to be 0.5-0.7, work can be effectively guaranteed, and power increase is avoided.

Specifically, the ratio of the outer diameter dimension of the first hub 120 to the outer diameter dimension D3 of the first blade 110 may be 0.55-0.65.

In the present embodiment, the first hub 120 has a wall thickness of 2mm to 6 mm. The first hub 120 is a bridge connecting the first blade 110 and the second blade 210. By controlling the wall thickness of the first hub 120, the strength of connection between the first blade 110 and the second blade 210 can be maintained, the structural stability can be improved, and the overall coordination of the axial flow impeller 10 can be improved. Specifically, the wall thickness of the first hub 120 is 4 mm.

Optionally, the ratio of the diameter dimension D1 of the second hub 220 to the outer diameter dimension D2 of the second blade 210 is 0.2-0.3. On one hand, the second hub 220 can be effectively connected with the rotating member, and on the other hand, the working and power of the second blade 210 can be effectively controlled by controlling the ratio of the outer diameter of the second hub 220 to the outer diameter of the second blade 210.

Referring to fig. 4 and 5, in an embodiment, a portion of the second blade 210 contacting the second hub 220 forms a second blade root 212, the second blade 210 further has a second blade tip 214, the second blade tip 214 is a portion of the second blade 210 away from the second blade root 212, an installation angle of the second blade root 212 with respect to an axis of the second hub 220 is α 3, and an installation angle of the second blade tip 214 with respect to an axis of the second hub 220 is α 4, where α 4> α 3. The work efficiency of the second blade 210 is ensured, and the increase of the power consumption of the second blade 210 is avoided.

Optionally, the mounting angle α 3 of the second blade root 212 with respect to the axis of the second hub 220 is 30 ° to 50 °. And then, the work of the second blade 210 can be ensured, and the increase of power is avoided. Specifically, the mounting angle α 3 may be 30 °, 35 °, 40 °, 45 °, or 50 °.

Optionally, the mounting angle α 4 of the second blade tip 214 with respect to the axis of the second hub 220 is 60 ° to 75 °. The work of the second blade 210 can be ensured and the increase of power can be avoided. Specifically, the mounting angle α 4 may be 60 °, 65 °, 70 °, or 75 °.

In one embodiment, a line connecting opposite ends of the second blade root 212 is a chord line of the second blade root 212, a chord length of the chord line of the second blade root 212 is L3, a line connecting opposite ends of the second blade tip 214 is a chord line of the second blade tip 214, and a chord length of the chord line of the second blade tip 214 is L4, wherein L4> L3. The L4 and the L3 can effectively reduce the power consumption of the second blade 210, ensure certain work and further improve the energy efficiency ratio of the axial flow impeller 10.

Optionally, the chord length L3 of the chord line of the second blade root 212 is 20mm to 40mm, which can further effectively reduce the power consumption of the second blade 210, and ensure a certain work, thereby improving the energy efficiency ratio of the axial flow impeller 10.

Optionally, the chord length L4 of the chord line of the second blade tip 214 is 50mm to 70mm, which can further effectively reduce the power consumption of the second blade 210, and ensure a certain work, thereby improving the energy efficiency ratio of the axial flow impeller 10. In other embodiments, the chord length of the second blade root 212 chord line and the chord length of the second blade tip 214 chord line may also be increased as appropriate for increasing the overall size of the second fan blade 200, or decreased as appropriate for decreasing the overall size of the second fan blade 200.

In this embodiment, the second blade 210 has a slender integral blade shape, and the tip portion of the second blade 210 imitates the wing of a swallow, so that the blade is slender and round, and further the power of the second blade 200 is reduced while the air volume is ensured, and further the power of the axial flow impeller 10 is reduced, and the energy efficiency ratio of the axial flow impeller 10 is improved.

Referring to fig. 6, when the axial flow impeller 10 in the above embodiment is used, the air supply range is wide, the air is diffused outward after meeting at a certain position, the wind field is wider, the air volume is larger, and the wind feeling is softer and more comfortable. Meanwhile, the axial-flow impeller 10 of the above embodiment can effectively reduce the "hum" at the time of high-speed rotation, and improve the sound quality.

The performance comparison data of the axial-flow impeller 10 in the above embodiment with a conventional fan provided with five blades is shown in the following table:

fan blade	Air volume (m)3/min)	Noise (dB)	Power (W)
				Traditional five-blade fan	28	58	28
Axial flow impeller 10 in the present application	30	57	23

From the test data in the above table, it can be seen that the overall performance of the axial flow impeller 10 is significantly improved, the air volume is improved by 2 air volumes, the noise is reduced by 1dB, the power is reduced by 5W, and the overall energy efficiency ratio of the axial flow impeller 10 is increased.

The fan in one embodiment comprises the axial flow impeller 10 of any of the embodiments described above. Specifically, the fan further includes a rotating member for driving the axial flow impeller 10 to rotate. Further, the rotating member is disposed on the second hub 220. Wherein the rotating member is a motor.

Referring to fig. 1, in an embodiment, the axial flow impeller 10 further includes a mounting member 300, the mounting member 300 is disposed in the second hub 220, and the rotating member is mounted on the mounting member 300. The installation of the rotation member can be facilitated by providing the installation member 300, and thus the rotation of the axial flow impeller 10 by the rotation member can be facilitated.

Specifically, the mounting member 300 includes a fitting portion 310 and a connecting portion 320, and the fitting portion 310 is disposed on the second hub 220 through the connecting portion 320. The mating portion 310 is for mating with a rotating member. Further, the fitting portion 310 is integrally formed on the inner wall of the second hub 220 through the connecting portion 320, so that the stability of the mounting member 300 disposed on the second hub 220 can be improved, and the stability of the rotating member mounted on the axial flow impeller 10 can be further improved.

In the present embodiment, the fan is a floor-standing circulation fan. In other embodiments, the fan may be other types of fans.

The above-mentioned embodiments only express a few embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.