Axial flow fan blade and axial flow fan with same

Abstract

The axial flow fan blade comprises a blade body and a winglet, the blade body is provided with a blade root, a blade top and a suction surface, the winglet is located at the blade top and extends towards the side where the suction surface is located, the winglet is provided with an outer side face opposite to the blade root, and a pit is formed in the outer side face. According to the axial flow fan blade, when the axial flow fan blade is applied to an axial flow fan, the small wings can block airflow flowing in the radial direction, and therefore the radial flowing loss of the airflow can be reduced, and the blade torque can be reduced. Meanwhile, the pits formed in the outer side faces of the small wings can adsorb airflow, blade top vortexes generated on the outer sides of the blade tops are broken, vortex shedding is reduced, and therefore pneumatic noise can be lowered, and noise reduction of the axial flow fan is achieved. Due to the fact that the small wings can reduce the radial flow loss of airflow and the pits in the small wings can adsorb the airflow to reduce vortex shedding, the flow state of the surfaces of the blades can be improved, and the performance of the axial flow fan is remarkably improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of axial flow fans, and in particular relates to an axial flow fan blade and an axial flow fan having the same. Background Art

[0002] When the existing axial flow fan runs at a higher speed, the interaction between the blades and the airflow and the action of centrifugal force will cause the airflow to generate radial flow on the blades and generate blade tip vortices on the outside of the blade tips, resulting in radial flow losses and vortex shedding noise on the blades, causing the performance of the axial flow fan to decline. Therefore, designing an axial flow fan with a lower noise level and good aerodynamic performance is more in line with market demand. Summary of the invention

[0003] Therefore, the present invention provides an axial flow fan blade, which can solve the technical problem that when the axial flow fan runs at a higher speed, due to the interaction between the blade and the airflow and the action of centrifugal force, the airflow will generate radial flow on the blade and generate blade tip vortex on the outside of the blade tip, thereby causing radial flow loss and vortex shedding noise in the blade.

[0004] In order to solve the above problems, the present invention provides an axial flow fan blade, including a blade body and a winglet, the blade body having a blade root, a blade top and a suction surface, the winglet is located at the blade top and extends toward the side where the suction surface is located, the winglet has an outer side surface facing away from the blade root, and a pit is formed on the outer side surface.

[0005] In some embodiments, the thickness of the winglet is t, the depth of the pit is h, and 0.35≤h / t≤0.65.

[0006] In some embodiments, the thickness of the winglet is t, the diameter of the pit is D, and 1.5≤D / t≤2.8.

[0007] In some embodiments, the number of the dimples is multiple, and the dimples are spaced apart along the width direction of the winglet. The distance between the center points of two adjacent dimples is L1, and the diameter of the dimple is D, 1.5≤L l / D≤3.5.

[0008] In some embodiments, there are multiple pits, each of which is spaced apart along the length direction of the winglet, the distance between the center points of two adjacent pits is L2, the diameter of the pit is D, and 1.1≤L2 / D≤1.6.

[0009] In some embodiments, the blade body further has a leading edge and a trailing edge, the chord length formed by a line between the midpoint of the leading edge and the midpoint of the trailing edge is C, the width of the winglet is W, and 0.02≤W / C≤0.05.

[0010] In some embodiments, the thickness of the winglet is t, 0.10≤t / W≤0.25.

[0011] In some embodiments, the length of the winglet is greater than or equal to one quarter of the length of the blade top; and / or the blade body also has a leading edge and a trailing edge, the winglet has a starting end and an ending end, the starting end is connected to the top end of the leading edge, and the ending end is located between the starting end and the top end of the trailing edge.

[0012] In some embodiments, the installation angle of the winglet on the blade body is a, 75°≤a≤105°; and / or the winglet and the blade body are integrally formed.

[0013] The present invention also provides an axial flow fan, comprising the above-mentioned axial flow fan blades.

[0014] The present invention provides an axial flow fan blade and an axial flow fan having the same, which have the following beneficial effects:

[0015] When the axial flow fan blade of the present application is applied to an axial flow fan, since a winglet is provided at the blade tip of the blade body, the winglet can hinder the radial flow of the airflow, thereby reducing the radial flow loss of the airflow and reducing the blade torque. At the same time, the pit formed on the outer surface of the winglet can absorb the airflow, break up the blade tip vortex generated on the outer side of the blade tip, reduce vortex shedding, and thus reduce aerodynamic noise, thereby achieving noise reduction for the axial flow fan. Because the winglet can reduce the radial flow loss of the airflow and the pit on it can absorb the airflow and reduce vortex shedding, it can improve the flow state on the blade surface, so that the performance of the axial flow fan is significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0017] Figure 1 A schematic diagram of the structure of an axial flow fan blade according to an embodiment of the present invention;

[0018] Figure 2 A schematic structural diagram of a winglet of an axial flow fan blade according to an embodiment of the present invention;

[0019] Figure 3 is a cross-sectional view of an axial flow fan blade according to an embodiment of the present invention;

[0020] Figure 4 A schematic structural diagram of an axial flow fan impeller according to an embodiment of the present invention;

[0021] Figure 5 for Figure 4 An enlarged schematic diagram of the axial flow fan impeller at point A of an embodiment of the present invention;

[0022] Figure 6 for Figure 4 An enlarged schematic diagram of the axial flow fan impeller at B of an embodiment of the present invention;

[0023] Figure 7 is a schematic structural diagram of an axial flow fan impeller according to an embodiment of the present invention from another viewing angle;

[0024] Figure 8 FIG. 4 is a top view of an axial flow fan impeller according to an embodiment of the present invention.

[0025] The reference numerals are as follows:

[0026] 1. Blade body; 2. Winglet; 3. Blade root; 4. Blade tip; 5. Suction surface; 6. Pit; 7. Leading edge; 8. Trailing edge; 9. Pressure surface; 10. Hub. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the devices or elements referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention. The directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0029] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0030] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0031] See also Figures 1 to 8 As shown, according to an embodiment of the present invention, an axial flow fan blade is provided, including a blade body 1 and a winglet 2, the blade body 1 having a blade root 3, a blade top 4 and a suction surface 5, the winglet 2 is located at the blade top 4 and extends to the side where the suction surface 5 is located, the winglet 2 has an outer side surface facing away from the blade root 3, and a pit 6 is formed on the outer side surface.

[0032] In this technical solution, when the axial flow fan blade of the present application is applied to an axial flow fan, since the winglet 2 is provided at the blade top 4 of the blade body 1, the winglet 2 can hinder the radial flow of the airflow, thereby reducing the radial flow loss of the airflow and reducing the blade torque. At the same time, the pit 6 formed on the outer surface of the winglet 2 can absorb the airflow, break up the blade top vortex generated on the outer side of the blade top, reduce vortex shedding, and thus reduce aerodynamic noise, thereby achieving noise reduction for the axial flow fan. Because the winglet 2 can reduce the radial flow loss of the airflow and the pit 6 thereon can absorb the airflow and reduce vortex shedding, the flow state on the blade surface can be improved, so that the performance of the axial flow fan is significantly improved. Among them, the blade body 1 also has a pressure surface 9.

[0033] See also Figure 4 and Figure 5 As shown, the thickness of the winglet 2 is t, the depth of the pit 6 is h, and 0.35≤h / t≤0.65.

[0034] In this embodiment, when the pit 6 is shallow, the bottom of the pit 6 cannot generate a small adsorption vortex, and cannot play the role of adsorbing the airflow to break the blade tip vortex; when the pit 6 is deep, it has a great impact on the structural strength of the winglet 2. Experiments show that when the pit depth h of the pit 6 and the thickness t of the winglet 2 meet 0.35≤h / t≤0.65, the adsorption effect on the airflow and the structural strength of the winglet 2 can be taken into account at the same time.

[0035] See also Figure 4 and Figure 5 As shown, the diameter of the pit 6 is D, 1.5≤D / t≤2.8.

[0036] In this technical solution, when the diameter of the pit 6 is small, the airflow generating the tip vortex will directly pass over the pit 6; when the diameter of the pit 6 is large, it is not enough to guide the airflow and absorb the airflow. Experiments show that when the diameter D of the pit 6 and the thickness t of the winglet 2 satisfy 1.5≤D / t≤2.8, the airflow can be better absorbed.

[0037] As a specific implementation, there are multiple pits 6, each pit 6 is spaced apart along the width direction of the winglet 2, the distance between the center points of two adjacent pits 6 is L1, the diameter of the pit 6 is D, 1.5≤L l / D≤3.5.

[0038] In this embodiment, when the distance L1 between the center points of two adjacent dimples 6 in the width direction of the winglet 2 and the diameter D of the dimple 6 satisfy 1.5≤L l When / D≤3.5, it indicates that the dimples 6 in the same row are evenly distributed on the winglet 2 and have appropriate spacing therebetween, and thus the dimples 6 in the same row can better act on the airflow, thereby better absorbing the airflow and breaking up the blade tip vortex.

[0039] More specifically, there are multiple pits 6, and the pits 6 are spaced apart along the length direction of the winglet 2. The distance between the center points of two adjacent pits 6 is L2, and the diameter of the pit 6 is D, 1.1≤L2 / D≤1.6.

[0040] In this technical solution, when the distance L2 between the center points of two adjacent pits 6 in the length direction of the winglet 2 and the diameter D of the pit 6 satisfy 1.1≤L2 / D≤1.6, it indicates that the pits 6 in the same row are evenly distributed on the winglet 2 and have a suitable spacing between each other, then the pits 6 in the same row can better act on the airflow, thereby better absorbing the airflow and breaking up the blade tip vortex.

[0041] It can be understood that, finally, each dimple 6 is evenly distributed in multiple rows and columns on the winglet 2, and the distance between the center points of two adjacent dimples 6 in the same row is L1, and the distance between the center points of two adjacent dimples 6 in the same column is L2. The function of the dimple 6 is to change the gas flow state by forming smaller adsorption vortices. When each dimple 6 is evenly distributed in multiple rows and columns on the winglet 2, it can ensure that when the gas flows through the outer side of the winglet 2, vortices with the same rotation tendency are generated, which helps to adsorb the airflow. In addition, the even distribution of each dimple 6 in multiple rows and columns on the winglet 2 can also ensure that each dimple 6 will not have inconsistent wear.

[0042] See also Figure 2 and Figure 3 As shown, the blade body 1 also has a leading edge 7 and a trailing edge 8, the chord length formed by the line between the midpoint of the leading edge 7 and the midpoint of the trailing edge 8 is C, the width of the winglet 2 is W, and 0.02≤W / C≤0.05.

[0043] In this embodiment, if the width W of the winglet 2 exceeds a reasonable range, the weight of the blade will increase, and more shaft work will be required to work, resulting in additional losses in the blade. At the same time, the tip vortex is generated within a certain range of the blade tip, not in the entire process. The overly wide part of the winglet does not act on the tip vortex, but increases the resistance, and does not improve the performance of the blade. Experiments show that when the width W of the winglet 2 and the average chord length C of the blade body 1 satisfy 0.02≤W / C≤0.05, the width of the winglet 2 can be within a reasonable range, and the blade has a suitable weight, which can not only improve the performance of the blade, but also does not cause additional losses to the blade. Among them, the chord length formed by the line between the midpoint of the leading edge 7 and the midpoint of the trailing edge 8 is the average chord length of the blade body 1.

[0044] See also Figure 2 As shown, the thickness of the winglet 2 is t, and 0.10≤t / W≤0.25.

[0045] In this technical solution, when the thickness t of the winglet 2 is small, the depth of the pit 6 formed will be small, and it will not be able to play the role of adsorbing airflow; when the thickness t of the winglet 2 is large, the weight of the blade will increase, resulting in additional loss of the blade. Experiments show that when the thickness t of the winglet 2 and the width W of the winglet 2 satisfy 0.10≤t / W≤0.25, the thickness of the winglet 2 can be within a reasonable range, and the blade can further have a suitable weight, so that not only can the pit 6 of appropriate depth be constructed on the winglet 2, but also no additional loss of the blade will occur. Among them, the winglet 2 is an arc-shaped body with appropriate width and thickness.

[0046] As a specific implementation manner, the length of the winglet 2 is greater than or equal to one quarter of the length of the blade tip 4 .

[0047] In this embodiment, the tip vortex is a rotating vortex formed at the blade tip due to the pressure difference between the upper and lower surfaces. The length of the winglet 2 is an important factor affecting the performance of the winglet 2. When the length of the winglet 2 is small, the winglet itself and the pits 6 formed thereon have a weak induction effect on the vortex at the blade tip, which is insufficient to improve efficiency and reduce noise. Therefore, in order to make the winglet 2 and the pits 6 thereon play a better role, the length of the winglet 2 needs to be greater than or equal to one quarter of the length of the blade tip 4. Among them, the length of the winglet 2 and the blade tip 4 refers to the arc length of the winglet 2 and the blade tip 4.

[0048] More specifically, the winglet 2 has a starting end and a trailing end. The starting end of the winglet 2 is connected to the top end of the leading edge 7 , and the trailing end is located between the starting end and the top end of the trailing edge 8 .

[0049] In this technical solution, since the airflow usually moves from the leading edge 7 of the blade body 1 to the trailing edge 8 of the blade body 1, when the starting end of the winglet 2 is connected to the top of the leading edge 7, the winglet 2 can better reduce the radial flow loss of the airflow, and at the same time, the pits 6 on the winglet 2 can better absorb the airflow to break up the blade tip vortex. Among them, the top of the leading edge 7 refers to the end where the leading edge 7 and the blade tip 4 are connected, and the top of the trailing edge 8 refers to the end where the trailing edge 8 and the blade tip 4 are connected.

[0050] See also Figure 4 and Figure 6 As shown, the installation angle of the winglet 2 on the blade body 1 is a, 75°≤a≤105°.

[0051] In this embodiment, when the installation angle of the winglet 2 on the blade body 1 is too large or too small, the effect of the winglet 2 on the radial flow of air will be weak. Experiments show that when the installation angle a of the winglet 2 on the blade body 1 satisfies 75°≤a≤105°, the effect of the winglet 2 on the radial flow of air is better. Among them, the installation angle of the winglet 2 is determined based on the airfoil chord line at the blade tip 4 as a reference, and is set at 90° perpendicular to the airfoil chord line at the blade tip 4.

[0052] As a specific implementation, the winglet 2 and the blade body 1 are integrally formed.

[0053] In this technical solution, if the winglet 2 and the blade body 1 are assembled together as a separate structure, when the axial flow fan rotates at high speed, the large centrifugal force can easily separate the winglet 2 and the blade body 1. However, when the winglet 2 and the blade body 1 are integrally formed, this problem can be well prevented from occurring.

[0054] The present invention also provides an axial flow fan, comprising the aforementioned axial flow fan blades, wherein the axial flow fan further comprises a hub 10, the number of the axial flow fan blades is multiple, each blade is installed along the circumference of the hub 10, and the blade root 3 of each blade is connected to the hub 10 as a whole.

[0055] It is easy for those skilled in the art to understand that, without conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.

[0056] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the protection scope of the present invention. The above are only preferred embodiments of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and variations can be made without departing from the technical principles of the present invention, and these improvements and variations should also be regarded as the protection scope of the present invention.

Claims

1. An axial flow fan blade, characterized in that: The invention comprises a blade body (1) and a winglet (2), wherein the blade body (1) has a blade root (3), a blade top (4) and a suction surface (5), the winglet (2) is located at the blade top (4) and extends toward the side where the suction surface (5) is located, and the winglet (2) has an outer side surface facing away from the blade root (3), and a pit (6) is formed on the outer side surface.

2. The axial flow fan blade according to claim 1, characterized in that: The thickness of the winglet (2) is t, the depth of the pit (6) is h, and 0.35≤h / t≤0.

65.

3. The axial flow fan blade according to claim 1, characterized in that: The thickness of the winglet (2) is t, the diameter of the pit (6) is D, and 1.5≤D / t≤2.

8.

4. The axial flow fan blade according to claim 1, characterized in that: The number of the pits (6) is multiple, and the pits (6) are spaced apart along the width direction of the winglet (2). The distance between the center points of two adjacent pits (6) is L1, and the diameter of the pit (6) is D, 1.5≤L l / D≤3.

5.

5. The axial flow fan blade according to claim 1, characterized in that: The number of the pits (6) is multiple, and the pits (6) are spaced apart along the length direction of the winglet (2), the distance between the center points of two adjacent pits (6) is L2, the diameter of the pit (6) is D, and 1.1≤L2 / D≤1.

6.

6. The axial flow fan blade according to any one of claims 1 to 5, characterized in that: The blade body (1) further comprises a leading edge (7) and a trailing edge (8), the chord length formed by a line connecting the midpoint of the leading edge (7) and the midpoint of the trailing edge (8) is C, the width of the winglet (2) is W, and 0.02≤W / C≤0.

05.

7. The axial flow fan blade according to claim 6, characterized in that: The thickness of the winglet (2) is t, 0.10≤t / W≤0.

25.

8. The axial flow fan blade according to any one of claims 1 to 5, characterized in that: The length of the winglet (2) is greater than or equal to one quarter of the length of the blade tip (4); and / or the blade body (1) further comprises a leading edge (7) and a trailing edge (8), the winglet (2) comprises a starting end and an ending end, the starting end is connected to the top end of the leading edge (7), and the ending end is located between the starting end and the top end of the trailing edge (8).

9. The axial flow fan blade according to any one of claims 1 to 5, characterized in that: The installation angle of the winglet (2) on the blade body (1) is a, 75°≤a≤105°; and / or the winglet (2) and the blade body (1) are integrally formed.

10. An axial flow fan, characterized in that: An axial flow fan blade comprising any one of claims 1 to 9.

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