CN112943688B

CN112943688B - Impeller

Info

Publication number: CN112943688B
Application number: CN201911267557.0A
Authority: CN
Inventors: 杨朝富; 洪立翰; 黄振柏; 张楯成; 徐国栋
Original assignee: Delta Electronics Inc
Current assignee: Delta Electronics Inc
Priority date: 2019-12-11
Filing date: 2019-12-11
Publication date: 2023-04-11
Anticipated expiration: 2039-12-11
Also published as: CN112943688A

Abstract

An impeller comprises a hub and a plurality of blades, wherein the hub is provided with a rotating shaft, and the blades are annularly arranged on the hub. In the running direction of the impeller, each fan blade area is divided into an inner edge, a front edge, an outer edge, a middle section part and a rear edge, the front edge, the outer edge and the rear edge surround three sides of the middle section part, in the radial direction, the upper surface of the fan blade close to the outer edge is provided with a valley-shaped structure, the lower surface of the fan blade corresponding to the valley-shaped structure is provided with a peak-shaped structure, the lower surface of the fan blade close to the rear edge or the front edge is also provided with a concave structure, and the concave structure is connected with the peak-shaped structure. The fan blade is provided with at least five wing sections from the inner edge to the outer edge, the fan blade is defined by continuously connecting a plurality of wing sections at different sections, a valley-shaped structure and a peak-shaped structure are respectively formed on the upper surface and the lower surface, the valley-shaped structure and the peak-shaped structure are positioned beside the outer edge, the depth of the valley-shaped structure is changed from the front edge to the rear edge, the height of the peak-shaped structure is changed from the front edge to the rear edge, and the change of the valley-shaped structure and the peak-shaped structure on the upper surface and the lower surface is continuously gradual.

Description

Impeller

Technical Field

The present invention relates to an impeller.

Background

Generally, fans can be classified into axial fans and centrifugal fans according to the direction relationship between the inlet air and the outlet air of the fan. Generally, the airflow of an axial flow fan flows in from an air inlet and then flows out from an air outlet, and the direction of the airflow flowing in from the air inlet is substantially the same as the direction of the airflow flowing out from the air outlet.

The blade of a conventional axial fan is mostly designed by using NACA4-digit or 5-digit airfoil sections and combining a blade stacking manner of 2 to 4 equal parts, and the airfoil sections located at different sections are continuously connected to form a three-dimensional blade. However, this design method will not be easy to describe effectively for the fine and smooth part of the blade surface. Moreover, each segment of the fan blade is not easy to change in order to maintain the continuity of the curvature of the fan blade. In addition, the maximum forward inclination angle of the fan blades of the conventional silent fan is generally 25 to 36 degrees, but if a larger forward inclination angle is used, the fan characteristics are liable to deteriorate.

Disclosure of Invention

The present invention aims to provide an impeller that solves at least one of the above problems.

In one embodiment, an impeller includes a hub having a rotation axis and a plurality of blades annularly disposed on the hub. In the running direction of the impeller, each fan blade is divided into an inner edge, a front edge, an outer edge, a middle section part and a rear edge, wherein the front edge, the outer edge and the rear edge surround three sides of the middle section part, in the radial direction, the upper surface of the fan blade close to the outer edge is provided with a valley-shaped structure, the lower surface of the fan blade is provided with a peak-shaped structure corresponding to the valley-shaped structure, the lower surface of the fan blade is also provided with a concave structure close to the rear edge or the front edge, and the concave structure is connected with the peak-shaped structure. The fan blade is provided with at least five wing sections from the inner edge to the outer edge, the fan blade is defined by continuously connecting a plurality of wing sections at different sections, so that the valley-shaped structure and the peak-shaped structure are respectively formed on the upper surface and the lower surface and are positioned beside the outer edge, the depth of the valley-shaped structure is changed from the front edge to the rear edge, the height of the peak-shaped structure is changed from the front edge to the rear edge, and the change of the valley-shaped structure and the peak-shaped structure on the upper surface and the lower surface is continuously gradual.

In one embodiment, the recessed structure is connected to the outer rim.

In one embodiment, the recessed feature is connected to the trailing edge or the leading edge.

In one embodiment, the lower surface has a region from the trailing edge toward the leading edge to a recessed boundary, a ratio of a distance between the recessed boundary and the trailing edge to a distance between the recessed boundary and the leading edge is less than 1/2, and the recessed structure is proximate to the trailing edge within the region and does not extend beyond the recessed boundary.

In one embodiment, the lower surface has a region from the leading edge toward the trailing edge to a recessed boundary, a ratio of a distance between the recessed boundary and the leading edge to a distance between the recessed boundary and the trailing edge is less than 1/2, and the recessed structure is located near the leading edge in the region and does not extend beyond the recessed boundary.

In one embodiment, the area of the concave structure on the lower surface is not more than 1/3 of the area of the lower surface

In one embodiment, the leading edge of each fan blade has a front-most end, when looking down on the upper surfaces of the fan blades, a plurality of imaginary lines are respectively connected to the front-most ends from the rotating shaft, and every two adjacent imaginary lines define an included angle, and the included angles are different from each other.

In one embodiment, the valley structure connects the leading edge and the trailing edge, and the peak structure connects the leading edge and the trailing edge.

In one embodiment, an impeller includes a hub having a rotation axis and a plurality of blades annularly disposed on the hub. In the running direction of the impeller, each fan blade is divided into an inner edge, a front edge, an outer edge, a middle section part and a rear edge, wherein the front edge, the outer edge and the rear edge surround three sides of the middle section part, in the radial direction, the upper surface of the fan blade close to the outer edge is provided with a valley structure, the lower surface of the fan blade is provided with a peak structure corresponding to the valley structure, the lower surface of the fan blade is also provided with a concave structure close to the rear edge or the front edge, the concave structure is connected with the peak structure, the concave structure is connected with the outer edge, and the concave structure is connected with the rear edge or the front edge. The fan blade is provided with at least five wing sections from the inner edge to the outer edge, the fan blade is defined by continuously connecting a plurality of wing sections at different sections, so that the valley-shaped structure and the peak-shaped structure are respectively formed on the upper surface and the lower surface and are positioned beside the outer edge, the depth of the valley-shaped structure is changed from the front edge to the rear edge, the height of the peak-shaped structure is changed from the front edge to the rear edge, and the change of the valley-shaped structure and the peak-shaped structure on the upper surface and the lower surface is continuously gradual.

In one embodiment, the area of the recessed structure on the lower surface is not more than 1/3 of the area of the lower surface, the leading edge of each fan blade has a front end, when looking down on the upper surfaces of the fan blades, a plurality of imaginary lines are respectively connected to the front ends from the rotating shaft, every two adjacent imaginary lines define an included angle, the included angles are different from each other, the valley structure connects the leading edge and the trailing edge, and the peak structure connects the leading edge and the trailing edge.

In one embodiment, an impeller includes a hub having a rotation axis and a plurality of blades annularly disposed on the hub. In the running direction of the impeller, each fan blade is divided into an inner edge, a front edge, an outer edge, a middle section part and a rear edge, wherein the front edge, the outer edge and the rear edge surround three sides of the middle section part, in the radial direction, the upper surface of the fan blade close to the outer edge is provided with a valley-shaped structure, the lower surface of the fan blade is provided with a peak-shaped structure corresponding to the valley-shaped structure, and the lower surface of the fan blade is also provided with a concave structure close to the rear edge or the front edge. The fan blade is provided with at least five wing sections from the inner edge to the outer edge, and the fan blade is defined by continuously connecting a plurality of wing sections at different sections so as to respectively form the valley-shaped structure and the peak-shaped structure on the upper surface and the lower surface, wherein the valley-shaped structure and the peak-shaped structure are positioned beside the outer edge.

In one embodiment, the recessed structures connect the peak structures.

In one embodiment, the recessed structure is connected to the outer rim.

In one embodiment, the lower surface has a region from the trailing edge toward the leading edge to a recessed boundary, a ratio of a distance between the recessed boundary and the trailing edge to a distance between the recessed boundary and the leading edge is less than 1/2, and the recessed structure is located near the trailing edge within the region and does not extend beyond the recessed boundary.

In one embodiment, the lower surface has a region from the leading edge toward the trailing edge to a recessed boundary, a ratio of a distance between the recessed boundary and the leading edge to a distance between the recessed boundary and the trailing edge is less than 1/2, and the recessed structure is proximate to the leading edge in the region and does not extend beyond the recessed boundary.

In one embodiment, a depth of the valley structure varies along a direction from the leading edge to the trailing edge, a height of the peak structure varies along the direction, and the variation of the valley structure and the peak structure at the upper surface and the lower surface is continuously gradual.

In one embodiment, a fan uses the impeller.

In the impeller and the fan blade of the fan, the height from the front edge to the horizontal plane where the lowest point of the fan blade is located is gradually reduced and then gradually increased in the direction from the hub to the direction away from the rotating shaft, so that when the fan rotates, the intensity of airflow turning over from the lower surface of the fan blade due to the pressure difference between the upper surface and the lower surface of the fan blade can be effectively reduced, airflow disturbance on the fan blade is further reduced, and noise is effectively reduced. In addition, the upper surface of the fan blade close to the outer edge is provided with a valley structure in the radial direction, and the lower surface of the fan blade is provided with a peak structure corresponding to the valley structure, so that the noise and the turbulence caused by the rotation of the impeller can be reduced. The design of the fan blades can improve the wind pressure and the wind quantity and effectively reduce the noise. In addition, the fan blade back face concave structure is a supercharging design, and the noise can be reduced due to the concave structure and the design of unequal intervals of the blades, so that the material cost is saved, and the product is optimized.

Drawings

Fig. 1A to 1C are perspective views of an impeller according to a preferred embodiment of the present invention.

Fig. 1D is a top view of the impeller shown in fig. 1A.

FIG. 1E is a half view of the impeller shown in FIG. 1A.

FIG. 2A is a schematic view of an airfoil section.

FIG. 2B is a schematic view of the installation of the airfoil section.

Fig. 3A is a top view of a portion of the impeller.

FIG. 3B is a side view of the fan blade at line AA of FIG. 3A.

FIG. 3C is a side view of the fan blade at line BB of FIG. 3A.

FIG. 3D is a side view of the fan blade at line CC of FIG. 3A.

Fig. 4A and 4B are perspective views of an impeller according to an embodiment.

Fig. 4C is a partial enlarged view of the impeller shown in fig. 4A.

Fig. 4D is a top view of the impeller shown in fig. 4A.

Fig. 5A and 5B are perspective views of an impeller according to an embodiment.

Fig. 6A and 6B are perspective views of an impeller according to an embodiment.

The reference numbers are as follows:

1: wheel hub

11: outer surface

12: the top surface

13: hub axle center

14: rotating shaft

2: fan blade

21: inner edge

22: outer edge

23: leading edge

24: trailing edge

25: upper surface of

26: lower surface of

27: middle section

I: impeller wheel

R0: reference line

Psi: front rake

A: wing section

R: center of curvature

d: axial mounting position

L: chord length

C: arc line

P: parameter(s)

Dmax: maximum thickness

Dtail: trailing edge thickness

α: wind inlet angle

θ: bow corner

Beta: mounting angle

G: valley-shaped structure

Q: peak like structure

Detailed Description

An impeller and a fan according to preferred embodiments of the present invention will be described with reference to the accompanying drawings, in which like elements will be described with like reference numerals.

Fig. 1A to 1C are perspective views of an impeller I according to a preferred embodiment of the present invention, fig. 1B is a top view of the impeller I shown in fig. 1D, and fig. 1E is a half view of the impeller I shown in fig. 1A. The fan frame comprises a hub 1 and a plurality of fan blades 2, the fan blades 2 are arranged on the hub 1 in a surrounding mode, and the impeller I can be used for a fan. In the embodiment, five blades 2 are taken as an example for illustration, and for clarity and convenience of illustration, fig. 1A only shows one blade 2 of the five blades 2.

As shown in fig. 1A to 1C, the hub 1 is a cylindrical structure and has an outer surface 11, a top surface 12, a hub axle 13 and a rotation shaft 14. In the present embodiment, the hub axle center 13 is perpendicular to the top surface 12, i.e. the extending direction of the hub axle center 13 is parallel to the normal vector of the top surface 12. The hub axle 13 is connected with a rotating shaft 14.

The fan blades 2 are attached to the outer surface 11 of the hub 1. In the operation direction of the impeller I, each blade 2 is divided into an inner edge 21, a leading edge 23, an outer edge 22, a middle section 27 and a trailing edge 24, the leading edge 23, the outer edge 22 and the trailing edge 24 surround three sides of the middle section 27, and the height of the leading edge 23 from the horizontal plane where the lowest point of the blade 2 is located is gradually reduced and then gradually increased in the direction from the hub 1 to the rotating shaft 14. In the radial direction, the upper surface 25 of the fan blade 2 near the outer edge 22 has a valley structure G, and the lower surface 26 of the fan blade 2 has a peak structure Q corresponding to the valley structure G. The valley structure G extends from near the leading edge 23 to the trailing edge 24 and has a depth that gradually becomes deeper and shallower. The peak-like structure Q extends from near the leading edge 23 to the trailing edge 24 and has a height that gradually becomes convex and then gradually flattens.

In this embodiment, the four edges are curved instead of straight. Inner edge 21 is the edge where blade 2 is connected to outer surface 11 of hub 1, while outer edge 22 is located opposite inner edge 21, i.e. the edge of blade 2 that is remote from hub 1. In addition, the front edge 23 is the wind inlet edge of the fan blade 2 when the impeller I rotates, and the rear edge 24 is arranged opposite to the front edge 23, that is, the wind outlet edge of the fan blade 2. Wherein the inner edge 21 connects the leading edge 23 and the trailing edge 24, and the outer edge 22 also connects the leading edge 23 and the trailing edge 24.

The fan blades 2 are partially overlapped with the front and rear fan blades 2 in the axial direction at the position close to the hub 1, so that the wind pressure and the wind volume are improved. The overlapping portion is indicated by symbol OP in fig. 1D.

As shown in fig. 1A, 1D and 1E, the inner edge 21 and the outer edge 22 may have a plurality of airfoil sections (airfoil) a therebetween. It should be noted that the "airfoil section" referred to herein is a cambered surface rather than a plane, and the cambered airfoil section a is formed by intersecting a cambered surface, which is a virtual arc line extending along the extending direction of the hub axle 13, with the fan blade 2, wherein the curvature center R corresponding to the virtual arc line is located in the extending direction of the hub axle 1, and the curvature radius R of the virtual arc line determines the position of the airfoil section a. Here, the present embodiment is described by taking seven airfoil sections a (the first airfoil section A1 to the seventh airfoil section A7) as an example, and the positions of the airfoil sections a are respectively defined by seven different curvature radii R (the first curvature radius R1 to the seventh curvature radius R7), wherein the lengths of the first curvature radius R1 to the seventh curvature radius R7 are gradually increased. In the present embodiment, the first radius of curvature R1 is the same as the radius of the outer surface of the hub 1, i.e. the first airfoil section A1 is the inner edge 21 of the fan blade 2, and the seventh airfoil section A7 is the outer edge 22 of the fan blade 2.

Fig. 2A and 2B are a schematic view of a wing section and an installation schematic view of the wing section, respectively. In the present embodiment, each airfoil section a includes the following airfoil parameters:

arc (chamber line) C: the centerline of the airfoil section from the leading edge 23 to the trailing edge 24, i.e., at the upper surface, is equidistant from the camber line C as the lower surface. The present embodiment includes first to seventh camber lines C1 to C7, which correspond to the first to seventh airfoil sections A1 to A7, respectively.

Chord length (chord line) L: the straight line connecting the leading edge 23 and the trailing edge 24 is also called a mounting line. The present embodiment includes first to seventh chord lengths L1 to L7, which correspond to the first to seventh airfoil sections A1 to A7, respectively.

Angle of incidence α: the included angle between the direction (or vector) of air entering the fan blade 2 and the chord length L. The present embodiment comprises a first to a seventh inlet angle α 1 to α 7, which correspond to the first to the seventh aerofoil sections A1 to A7, respectively. In the running direction of the impeller I, the wind inlet angle alpha 7 of the front edge 23 of the outer edge 22 of the fan blade 2 is the largest, thereby improving the wind pressure and the wind volume and effectively reducing the noise.

Bow angle θ: the acute angle at which the leading edge tangent of camber line C intersects the trailing edge tangent. The present embodiment includes a first bow angle θ 1 to a seventh bow angle θ 7, which correspond to the first wing section A1 to the seventh wing section A7 respectively, and are affected by the wind inlet angle, and the wind inlet angle θ 7 of the leading edge 23 of the outer edge 22 of the fan blade 2 is the largest in the operation direction of the impeller I.

Blade thickness (blade thickness), the thickness from the top surface to the bottom surface of the blade, including the maximum thickness Dmax and the trailing edge thickness Dtail. The maximum thicknesses Dmax of the present embodiment include first to seventh maximum thicknesses Dmax1 to Dmax7 corresponding to the first to seventh wing sections A1 to A7, respectively, and the trailing edge thicknesses Dtail include first to seventh trailing edge thicknesses Dtail1 to Dtail7 corresponding to the first to seventh wing sections A1 to A7, respectively. The position of the maximum thickness Dmax can be determined by a parameter P, which is a percentage position of the reference line segment, wherein the chord length L is used as a reference line segment, the leading edge 23 is used as a starting point, and the trailing edge 24 is used as an end point, and the parameter P is, for example, when the parameter P is 20%, the distance from the maximum thickness Dmax to the trailing edge 24 is four times the distance from the maximum thickness Dmax to the leading edge 23, wherein the parameter P is 50% in the embodiment, that is, the maximum thickness Dmax is located at the middle point of the chord length L.

In this way, the shape of each airfoil section a can be determined according to the values of the above-mentioned profile parameters. Referring to fig. 1D, 1E and 2B, each of the wing sections a with different radii of curvature R is connected to the hub 1 according to "installation parameters", wherein the installation parameters include:

mounting angle (stabilizer angle) β: the chord length L forms an angle with the horizontal plane HP. The present embodiment includes first to seventh stagger angles β 1 to β 7, which correspond to the first to seventh airfoil sections A1 to A7, respectively. The inclination relationship of each airfoil section a is determined by the magnitude of each mounting angle β. The first installation angle β 1 to the seventh installation angle β 7 have a continuously changing relationship, for example, the installation angle of the fan blade 2 gradually decreases from the first installation angle β 1 to the seventh installation angle β 7 in the direction from the hub 1 toward the rotation shaft 14; alternatively, the setting angle of the fan blades 2 increases from the first setting angle β 1 to the seventh setting angle β 7 in the direction away from the hub 1 and away from the rotating shaft 14, and then decreases or decreases and then increases. The gradual change of the installation angle can improve the wind pressure and the wind quantity.

Axial installation position d: on the axial direction several lines, the top surface 12 is defined as the axial origin, the direction of the top surface 12 connecting with the outer surface 11 is positive direction, and the other direction is negative direction, and the axial installation position d is the corresponding position of the front edge 23 of each airfoil section A on the axial direction several lines. The axial mounting position d may be positive or negative, and taking fig. 1C as an example, when the axial mounting position d is positive, the front edge 23 is located below the top surface 12, and when the axial mounting position d is negative, the front edge 23 is located above the top surface 12. In addition, the present embodiment includes first to seventh axial mounting locations d1 to d7 that correspond to the first to seventh airfoil sections A1 to A7, respectively. In the present embodiment, among the axial mounting positions d1 to d7, the seventh axial mounting position d7 of the seventh airfoil section A7 has the smallest value, and the seventh airfoil section A7 located on the outer edge 22 is located at the highest axial mounting position d7. In the present embodiment, the first axial mounting position d1 of the first airfoil section A1 is the second highest, and the third axial mounting position d3 of the third airfoil section A3 is the lowest. That is, the airfoil sections A1 and A7 on the inner edge 21 and the outer edge 22 are located at a higher axial installation position, and the airfoil sections (e.g., the third airfoil section A3 and the fourth airfoil section A4) located at a lower axial installation position, so that the height of the front edge 23 from the horizontal plane where the lowest point of the fan blade 2 is located is gradually decreased and then gradually increased in the direction from the hub 1 to the rotating shaft 14, and the front edge 23 of the fan blade 2 is concave.

Forward inclination angle ψ: the central part of the middle section 27 of the fan blade 2 is connected from the hub 1 to a position far away from the hub 1 to form a central virtual line, and the included angle between the normal line of the central part and the hub 1 and the central virtual line is the forward inclination angle. For each airfoil section A, the included angle between a connecting line of the middle section 27 between the front edge 23 and the rear edge 24 and the hub axis 13 and a reference line R0 is a forward inclination angle psi. The reference line R0 is a normal line at the connection point of the central portion and the hub 1, that is, a normal line at the middle of the first airfoil section A1. Please refer to fig. 1B. The present embodiment includes first to seventh forward inclination angles ψ 1 to ψ 6, which correspond to the second to seventh wing sections A1 to A7, respectively. The first airfoil section A1 and the seventh airfoil section A7 are located at the inner edge 21 and the outer edge 22, respectively, and the relationship between the rake angles of these airfoil sections is as follows:

ψ _n ＝(7+0.1*(n+1))+ψ _n-1

but when n =6, ψ ₆ ＝(7+0.1*(n+1))+ψ ₅ +ψ ₆ ’

In the present embodiment, the forward inclination angle of the middle step portion 27 is larger than 25 degrees, thereby reducing noise. The pitch angle ψ of the seventh airfoil section A7 of fan blade 2 at the outer edge 22 is greater than 40 degrees, for example 44.1 degrees. Psi ₆ ' is an external pressure, the seventh wing section A7 is subjected to psi ₆ ' which changes in anteversion angle psi more sharply and therefore more significantly. Thus, the leading edge 23 has a relatively sharp change in curvature, which reduces noise and turbulence caused by the rotation of the impeller I.

In the present embodiment, each fan blade 2 is defined by sequentially connecting the wing sections of the seven different sections in series. For example, the relationship between each of the airfoil sections a and the hub 1 is defined by the installation parameters, and after the first to seventh airfoil sections A1 to A7 are defined by the blade shape parameters and the installation parameters, the leading edges 23 and the trailing edges 24 of the airfoil sections a are connected to each other, so as to form the fan blade 2 of the present embodiment.

In the present embodiment, the upper surface 25 and the lower surface 26 of the fan blade 2 are defined by more than five (e.g. seven) different sections of airfoil sections being connected continuously, and the changes of the upper surface 25 and the lower surface 26, such as the valley structure G and the peak structure Q, are continuously gradual rather than abrupt protrusions or depressions. The valley structure G and the peak structure Q are located at the sixth airfoil section A6. Compared with the conventional design of stacking fan blades in an equal amount of 2 to 4, the present invention can design the surface of the fan blades more specifically, such as the valley structure G and the peak structure Q.

Fig. 3A is a top view of a portion of the fan, fig. 3B is a side view of the fan blades at line AA of fig. 3A, fig. 3C is a side view of the fan blades at line BB of fig. 3A, and fig. 3D is a side view of the fan blades at line CC of fig. 3A.

Referring to fig. 3A to 3D, in a direction from the hub 1 to a direction away from the rotating shaft 14, the height of the front edge 23 from the horizontal plane where the lowest point of the fan blade 2 is located is gradually decreased and then gradually increased, and the front edge 23 is concave. In the radial direction, the upper surface 25 of the fan blade 2 near the outer edge 22 has a valley structure G, and the lower surface 26 of the fan blade 2 has a peak structure Q corresponding to the valley structure G. The valley structure G and the peak structure Q are mainly located at the sixth airfoil section A6, and the sixth airfoil section A6 is mostly lower than the fifth airfoil section A5 and the seventh airfoil section A7 at the middle section 27 as viewed from the upper surface 25, thereby presenting a partial valley shape; the sixth airfoil section A6 is substantially lower than the fifth and seventh airfoil sections A5, A7 in the midsection 27 as viewed from the lower surface 26, and thus exhibits a local peak shape.

The outer edge 22 is set based on the seventh blade section A7 of fig. 2B, and since the rake angle of the seventh blade section A7 is much larger than the inner blade section, the leading edge 23 of the fan blade 2 projects forward at the outer edge 22 as viewed from above the top surface 12 of the hub 1. In addition, since the seventh airfoil section A7 is located at the highest seventh axial installation position d7, the outer edge 22 protrudes upward near the leading edge 23 in a side view. Thus, the outer edge 22 is raised near the leading edge 23 as a whole.

In the present embodiment, since the parameter P of the blade section is 50%, the maximum thickness Dmax of the blade sections is located at the midpoint of the chord length L. The outer edge 22 is still higher than the other airfoil sections between the front edge 23 of the seventh airfoil section A7 and the maximum thickness Dmax with the hub axis 13 as the center, and therefore, a section of the arc length of the outer edge 22 from the front edge 23 to the rear edge 23 is tilted up.

Therefore, the shape of fan blade 2 varies non-linearly from inner edge 21 to outer edge 22, and has an upturned structure on outer edge 22 adjacent to front edge 23, as shown in fig. 3B, and lower surface 26 has a height difference H from the lowest point to the highest point of line AA. Therefore, by the upward-warping structure of the outer edge 22 of the fan blade 2, when the fan F rotates, the intensity of the airflow that is turned over from the lower surface of the fan blade 2 due to the pressure difference between the upper and lower surfaces of the fan blade 2 can be effectively reduced, thereby reducing the airflow disturbance on the fan blade 2 and effectively reducing the noise.

In this embodiment, the shapes of the valley structure G and the peak structure Q are continuous and gradual on the upper and lower surfaces, and the shapes themselves are not greatly changed, so that the structures do not adversely affect the performance of the fan, and the wind pressure and the wind volume can be increased and the noise can be effectively reduced.

Fig. 4A and 4B are perspective views of an impeller according to an embodiment, fig. 4C is a partially enlarged view of the impeller shown in fig. 4A, and fig. 4D is a top view of the impeller shown in fig. 4A. Fig. 5A and 5B are perspective views of an impeller according to an embodiment, and fig. 6A and 6B are perspective views of an impeller according to an embodiment.

As shown in fig. 4A to 4D, an impeller Ia includes a hub 1 and a plurality of blades 2a, the hub 1 has a rotating shaft 14, and the blades 2a are disposed around the hub 1. In the operation direction of the impeller Ia, each blade 2a is divided into an inner edge 21a, a front edge 23a, an outer edge 22a, a middle section 27a and a rear edge 24a, wherein the front edge 23a, the outer edge 22a and the rear edge 24a surround three sides of the middle section 27 a. In the radial direction, the upper surface 25a of the fan blade 2a near the outer edge 22a has a valley structure Ga, the lower surface 26a of the fan blade 2a has a peak structure Qa corresponding to the valley structure Ga, and the lower surface 26a of the fan blade 2a has a recess structure S near the rear edge 24a or the front edge 23a. The fan blades 2a have at least five aerofoil sections from the inner edge 21a to the outer edge 22a, for example seven aerofoil sections as in the previous embodiment, or more aerofoil sections, for example ten or more, fifteen or more or twenty or more, etc. The fan blade 2a is defined by the continuous connection of the blade sections at different sections, so as to form a valley structure Ga and a peak structure Qa on the upper surface 25a and the lower surface 26a, respectively, and the valley structure Ga and the peak structure Qa are located beside the outer edge 22a. In addition, the wing sections of the fan blades 2a at different stages are continuously connected to define the valley structure Ga on the upper surface 25a, and the peak structure Qa and the valley structure S on the lower surface 26 a.

In fig. 4A and 4B, a depth of the valley structure Ga varies along a direction from the front edge 23a to the rear edge 24A, a height of the peak structure Qa varies along the direction, and the variation of the valley structure Ga and the peak structure Qa on the upper surface 25a and the lower surface 26a is continuously gradual. The valley structure Ga connects the leading edge 23a and the trailing edge 24a, and the peak structure Qa connects the leading edge 23a and the trailing edge 24a. In other embodiments, the valley structure Ga may not connect the leading edge 23a and the trailing edge 24a, or only connect one of the leading edge 23a and the trailing edge 24 a; the peak structures Qa may not connect the leading edge 23a and the trailing edge 24a, or only connect one of the leading edge 23a and the trailing edge 24a.

In fig. 4A and 4B, the concave structures S connect the peak structures Qa, and the concave structures S connect the outer edges 22a. In other embodiments, the recessed structures S may not connect the peak structures Qa, and the recessed structures S may not connect the outer edge 22a.

The recessed feature S connects the trailing edge 24a or the leading edge 23a, or both the trailing edge 24a and the leading edge 23a. These modes are shown in fig. 4A and 4B, fig. 5A and 5B, and fig. 6A and 6B, respectively.

In fig. 4A and 4B, the recessed structure S connects the trailing edge 24A, the lower surface 26a has a region 261a from the trailing edge 24A toward the leading edge 23a to a recessed boundary 28a, a ratio of a distance between the recessed boundary 28a and the trailing edge 24A to a distance between the recessed boundary 28a and the leading edge 23a is less than 1/2, and the recessed structure S is close to the trailing edge 24A within the region 261a and does not exceed the recessed boundary 28a. The area occupied by the recessed structure S on the lower surface 26a is not more than 1/3 of the area of the lower surface 26 a.

In fig. 5A and 5B, the recessed feature S connects the leading edge 23B, the lower surface 26B has a region 262B from the leading edge 23B toward the trailing edge 24B to a recessed boundary 29B, the ratio of the distance between the recessed boundary 29B and the leading edge 23B to the distance between the recessed boundary 29B and the trailing edge 24B is less than 1/2, and the recessed feature S is adjacent to the leading edge 23B in the region 262B and does not extend beyond the recessed boundary 29B. The area occupied by the recessed structure S on the lower surface 26b is not more than 1/3 of the area of the lower surface 26 b.

In fig. 6A and 6B, the recessed structure S has two sections connecting the rear edge 24c and the front edge 23c. The recessed structure S connects the trailing edge 24c, the lower surface 26c has a region 261c from the trailing edge 24c toward the leading edge 23c to a recessed boundary 28c, a ratio of a distance between the recessed boundary 28c and the trailing edge 24c to a distance between the recessed boundary 28c and the leading edge 23c is less than 1/2, and the recessed structure S is near the trailing edge 24c in the region 261c and does not exceed the recessed boundary 28c. The area occupied by the concave structures S in the region 261c is not more than 1/3 of the area of the lower surface 26 c. The recessed structure S connects the front edge 23c, the lower surface 26c has a region 262c from the front edge 23c toward the rear edge 24c to a recessed boundary 29c, a ratio of a distance between the recessed boundary 29c and the front edge 23c to a distance between the recessed boundary 29c and the rear edge 24c is less than 1/2, and the recessed structure S is near the front edge 23c in the region 262c and does not exceed the recessed boundary 29c. The area occupied by the recessed structure S in the region 262c is not more than 1/3 of the area of the lower surface 26 c.

In fig. 4D, the front edge 23a of each vane 2a has a front-most end 231a, and when looking down on the upper surface 25a of the vanes 2a, a plurality of imaginary lines are respectively connected to the front-most ends 231a from the rotating shaft 14, every two adjacent imaginary lines define an included angle n, and the included angles n1 to n5 are different from each other. The maximum and minimum angle difference in the included angles n 1-n 5 is not more than 30 degrees, or not more than 15 degrees; the maximum and minimum angle difference is more than 1 degree, or more than 3 degrees, or more than 5 degrees.

In summary, in the impeller and the fan blade of the fan of the present invention, the height from the front edge to the horizontal plane at the lowest point of the fan blade is gradually decreased and then gradually increased in the direction from the hub to the direction away from the rotating shaft, so that when the fan rotates, the airflow intensity from the lower surface of the fan blade due to the pressure difference between the upper surface and the lower surface of the fan blade can be effectively reduced, thereby reducing the airflow disturbance on the fan blade and effectively reducing the noise. In addition, the upper surface of the fan blade close to the outer edge is provided with a valley structure in the radial direction, and the lower surface of the fan blade is provided with a peak structure corresponding to the valley structure, so that the noise and the turbulence caused by the rotation of the impeller can be reduced. The design of the fan blades can improve the wind pressure and the wind quantity and effectively reduce the noise. In addition, the fan blade back face concave structure is a supercharging design, and the noise can be reduced due to the concave structure and the design of unequal intervals of the blades, so that the material cost is saved, and the product is optimized.

The foregoing is by way of example only, and not limiting. It is intended that all equivalent modifications or variations without departing from the spirit and scope of the present invention shall be included in the appended claims.

Claims

1. An impeller, comprising:

a hub having a shaft; and

a plurality of fan blades, which are arranged around the hub, wherein each fan blade is divided into an inner edge, a front edge, an outer edge, a middle section part and a rear edge in the running direction of the impeller, wherein the front edge, the outer edge and the rear edge surround three sides of the middle section part, the upper surface of the fan blade close to the outer edge is provided with a valley-shaped structure in the radial direction, the lower surface of the fan blade is provided with a peak-shaped structure corresponding to the valley-shaped structure, the lower surface of the fan blade is also provided with a concave structure close to the rear edge or the front edge, and the concave structure is connected with the peak-shaped structure;

the fan blade is defined by continuously connecting a plurality of wing sections at different sections, so that the valley structure and the peak structure are respectively formed on the upper surface and the lower surface and are positioned beside the outer edge, the depth of the valley structure is changed from the front edge to the rear edge, the height of the peak structure is changed from the front edge to the rear edge, and the change of the valley structure and the peak structure on the upper surface and the lower surface is continuously and gradually.

2. The impeller of claim 1, wherein the recessed structure connects the outer rim.

3. The impeller of claim 1, wherein the recessed structure connects the trailing edge or the leading edge.

4. The impeller of claim 1 wherein the lower surface has a region from the trailing edge toward the leading edge to a recessed boundary, the ratio of the distance between the recessed boundary and the trailing edge to the distance between the recessed boundary and the leading edge being less than 1/2, the recessed feature being proximate to the trailing edge within the region and not extending beyond the recessed boundary.

5. The impeller of claim 1 wherein the lower surface has a region from the leading edge toward the trailing edge to a recessed boundary, the ratio of the distance between the recessed boundary and the leading edge to the distance between the recessed boundary and the trailing edge being less than 1/2, the recessed feature being proximate to the leading edge within the region and not beyond the recessed boundary.

6. The impeller of claim 1, wherein the recessed feature occupies no more than 1/3 of the area of the lower surface.

7. The impeller of claim 1, wherein the leading edge of each blade has a forward-most end, and when looking down at the upper surfaces of the blades, imaginary lines are respectively connected to the forward-most ends from the rotation axis, and every two adjacent imaginary lines define an included angle, and the included angles are different from each other.

8. The impeller of claim 1, wherein the valley structure connects the leading edge and the trailing edge, and the peak structure connects the leading edge and the trailing edge.

9. An impeller, comprising:

a hub having a shaft; and

a plurality of fan blades, which are arranged around the hub, wherein each fan blade is divided into an inner edge, a front edge, an outer edge, a middle section part and a rear edge in the running direction of the impeller, wherein the front edge, the outer edge and the rear edge surround three sides of the middle section part, in the radial direction, the upper surface of the fan blade close to the outer edge is provided with a valley structure, the lower surface of the fan blade is provided with a peak structure corresponding to the valley structure, the lower surface of the fan blade is also provided with a concave structure close to the rear edge or the front edge, the concave structure is connected with the peak structure, the concave structure is connected with the outer edge, and the concave structure is connected with the rear edge or the front edge;

the fan blade is defined by continuously connecting a plurality of wing sections at different sections, so that the valley structure and the peak structure are respectively formed on the upper surface and the lower surface and are positioned beside the outer edge, the depth of the valley structure is changed from the front edge to the rear edge, the height of the peak structure is changed from the front edge to the rear edge, and the change of the valley structure and the peak structure on the upper surface and the lower surface is continuously gradual.

10. The impeller of claim 9, wherein the recessed feature occupies no more than 1/3 of the area of the lower surface;

the front edge of each fan blade is provided with a foremost end, when looking down the upper surfaces of the fan blades, a plurality of imaginary lines are respectively connected to the foremost ends from the rotating shaft, every two adjacent imaginary lines define an included angle, and the included angles are different from each other;

wherein, the valley structure connects the front edge and the rear edge, and the peak structure connects the front edge and the rear edge.

11. An impeller, comprising:

a hub having a shaft; and

the impeller comprises a hub, a plurality of blades and a plurality of blades, wherein the blades are arranged on the hub in a surrounding manner, each blade is divided into an inner edge, a front edge, an outer edge, a middle section part and a rear edge in the running direction of the impeller, the front edge, the outer edge and the rear edge surround three sides of the middle section part, the upper surface of the blade close to the outer edge is provided with a valley-shaped structure in the radial direction, the lower surface of the blade is provided with a peak-shaped structure corresponding to the valley-shaped structure, and the lower surface of the blade is provided with a concave structure close to the rear edge or the front edge;

the fan blade is defined by continuously connecting a plurality of wing sections at different sections so as to respectively form the valley structure and the peak structure on the upper surface and the lower surface, and the valley structure and the peak structure are positioned beside the outer edge.

12. The impeller of claim 11, wherein the recessed features connect the peak features.

13. The impeller of claim 11, wherein the recessed structure connects the outer rim.

14. The impeller of claim 11, wherein the recessed feature connects the trailing edge or the leading edge.

15. The impeller of claim 11 wherein the lower surface has a region from the trailing edge toward the leading edge to a recessed boundary, the ratio of the distance of the recessed boundary from the trailing edge to the distance of the recessed boundary from the leading edge being less than 1/2, the recessed feature being located within the region near the trailing edge and not beyond the recessed boundary.

16. The impeller of claim 11 wherein the lower surface has a region from the leading edge toward the trailing edge to a recessed boundary, the ratio of the distance between the recessed boundary and the leading edge to the distance between the recessed boundary and the trailing edge being less than 1/2, the recessed feature being located within the region near the leading edge and not beyond the recessed boundary.

17. The impeller of claim 11, wherein the recessed feature occupies no more than 1/3 of the area of the lower surface.

18. The impeller of claim 11, wherein the leading edge of each blade has a forward-most end, and when looking down at the upper surfaces of the blades, imaginary lines are respectively connected to the forward-most ends from the rotation axis, and every two adjacent imaginary lines define an included angle, the included angles being different from each other.

19. The impeller of claim 11 wherein a depth of the valley structure varies in a direction from the leading edge to the trailing edge, a height of the peak structure varies in the direction, and the variation of the valley structure and the peak structure at the upper surface and the lower surface is continuously gradual.

20. The impeller of claim 11 wherein the valley connects the leading edge and the trailing edge and the peak connects the leading edge and the trailing edge.