Axial-flow fan blade and fan

Abstract

The utility model relates to the technical field of fans, and discloses an axial flow fan blade and a fan, the axial flow fan blade comprises a plurality of blade units distributed at intervals along the circumferential direction, each blade unit comprises: a first blade comprising a first blade root part, a first blade top part, a first front edge part, a first tail edge part, a first suction surface and a first pressure surface; and the second blade comprises a second blade root part, a second blade top part, a second front edge part, a second tail edge part, a second suction surface and a second pressure surface, and the second tail edge part is connected with the first front edge part. Each blade unit is composed of the first blade and the second blade, a double-blade fitting mode is adopted, the blade units are novel in structure and attractive in appearance, and the blade units are closer to petal shapes.

Description

TECHNICAL FIELD

[0001] The utility model relates to fan technical field, concretely relates to axial flow fan blade and fan. BACKGROUND

[0002] The fan in the prior art usually adopts the traditional axial flow fan blade, the blade thereof is usually designed as a straight blade or a spiral blade, the traditional blade shape is limited, and no breakthrough has been made in appearance for many years, which easily causes consumer aesthetic fatigue and reduces product sales. In addition, the limited shape of the traditional blade limits the aerodynamic performance of the fan. SUMMARY

[0003] Therefore, the utility model provides an axial flow fan blade and fan to solve the problem of unattractive axial flow fan blade in the prior art.

[0004] In a first aspect, the utility model provides an axial flow fan blade, comprising: a plurality of blade units distributed at intervals in a circumferential direction, each blade unit comprising:

[0005] a first blade, comprising a first blade root, a first blade tip, a first leading edge, a first trailing edge, a first suction surface and a first pressure surface;

[0006] a second blade, comprising a second blade root, a second blade tip, a second leading edge, a second trailing edge, a second suction surface and a second pressure surface, wherein the second trailing edge is connected to the first leading edge.

[0007] Advantages: each blade unit is composed of a first blade and a second blade, adopts a double-blade fitting mode, has a novel structure and an attractive appearance, and is closer to a petal shape, and the aerodynamic performance of the fan can be improved due to the fact that each blade unit is composed of a first blade and a second blade.

[0008] In an optional embodiment, the axial flow fan blade comprises a hub, the blade unit is arranged on the hub, the outer diameter of the blade unit is D, the diameter of the hub is d, and 0.2≤d / D≤0.35.

[0009] Advantages: d / D refers to the hub ratio, which is an important design parameter of the axial flow fan, and a too large hub ratio will reduce the efficiency of the fan and the aerodynamic performance of the whole machine, and on the contrary, a too small hub ratio of the axial flow fan will cause airflow separation at the blade root of the fan blade, resulting in performance loss of the fan blade. Therefore, the hub ratio is between 0.2 and 0.35 in the embodiment, so that the efficiency of the fan can be ensured and the aerodynamic performance of the whole machine can be improved.

[0010] In an optional embodiment, from the first trailing edge to the first leading edge, the first blade tip is swept in a direction consistent with the rotation direction of the fan blade, and the net sweep angle gradually increases.

[0011] Beneficial effects: from the first trailing edge to the first leading edge, the first tip portion is swept in the same direction as the wind blade and the net sweep angle gradually increases, which can increase the flow guiding tendency of the first blade, reduce the double-blade disturbance, and facilitate the fitting of the first blade and the second blade.

[0012] In an alternative embodiment, the maximum outer edge radius of the blade unit is R, and an axial cylindrical base circle section with a radius of r is made with the center of the hub as the base point. The line connecting the center and the chord midpoint of the first blade root is the first line, the line connecting the chord midpoint of the first blade at the base circle section and the center is the second line, the included angle between the first line and the second line is A1, and A1 is the net sweep angle of the first blade. From the first blade root to the first blade tip, A1 gradually increases.

[0013] Beneficial effects: from the first blade root to the first blade tip, the net sweep angle of the first blade gradually increases, which can increase the flow guiding tendency of the first blade and reduce the double-blade disturbance.

[0014] In an alternative embodiment, 0°≤A1≤15°.

[0015] In an alternative embodiment, when r / R=0.4, A1 is 1°; when r / R=0.55, A1 is 4°; when r / R=0.7, A1 is 6°; when r / R=0.85, A1 is 9°; and when r / R=0.95, A1 is 10°.

[0016] In an alternative embodiment, from the first blade root to the first blade tip, the first trailing edge is swept in the same direction as the wind blade and the sweep angle of the first trailing edge gradually increases.

[0017] Beneficial effects: because the shape of the blade trailing edge affects the blade surface working area and the pressure gradient distribution on the blade surface, when the airflow on the blade surface passes through the trailing edge of the blade, local pressure pulsation force is easily generated due to vortex shedding, forming vortex noise. By sweeping the first trailing edge in the same direction as the wind blade and gradually increasing the sweep angle of the first trailing edge, the vortex shedding of the first trailing edge can be reduced.

[0018] In an alternative embodiment, the intersection of the first trailing edge and the outer diameter circle of the hub is a second point, the line connecting the second point and the center is a third line, the intersection of the base circle section and the first trailing edge is a first point, the tangent line of the first trailing edge at the first point is a first tangent line, the included angle between the third line and the first tangent line is A2, and A2 is the sweep angle of the first trailing edge. 0°≤A2≤55°.

[0019] Beneficial effects: by making 0°≤A2≤55°, the vortex shedding of the first trailing edge part can be reduced, and the first blade can meet the petal appearance modeling.

[0020] In an alternative embodiment, when r / R=0.4, A2 is 9°; when r / R=0.55, A2 is 13°; when r / R=0.7, A2 is 26°; when r / R=0.85, A2 is 35°; and when r / R=0.95, A2 is 41°.

[0021] In an alternative embodiment, from the second trailing edge part to the second leading edge part, the second blade top part is inversely swept relative to the wind blade rotation direction, and the net sweep angle gradually increases.

[0022] Beneficial effects: from the second trailing edge part to the second leading edge part, the second blade top part is inversely swept relative to the wind blade rotation direction, and the net sweep angle gradually increases, which can increase the flow guiding tendency of the second blade, reduce the double-blade disturbance, and facilitate the fitting of the second blade and the second blade.

[0023] In an alternative embodiment, the line connecting the center of the circle and the midpoint of the chord of the second blade root part is a fourth line, the line connecting the center of the circle and the midpoint of the chord of the second blade at the base circle section is a fifth line, the included angle between the fourth line and the fifth line is A3, A3 is the net sweep angle of the second blade, and A3 gradually increases from the second blade root part to the second blade top part.

[0024] In an alternative embodiment, -15°≤A3≤0°.

[0025] In an alternative embodiment, when r / R=0.4, A3 is 0°; when r / R=0.55, A3 is -3°; when r / R=0.7, A3 is -5°; when r / R=0.85, A3 is -6°; and when r / R=0.95, A3 is -8°.

[0026] In an alternative embodiment, from the second blade root part to the second blade top part, the second leading edge part is inversely swept relative to the wind blade rotation direction, and the sweep angle of the second leading edge part gradually increases.

[0027] Beneficial effects: the second leading edge part is inversely swept relative to the wind blade rotation direction, and the sweep angle of the second leading edge part gradually increases, which conforms to the petal modeling and makes the appearance more beautiful.

[0028] In an alternative embodiment, the intersection of the base circle section and the second leading edge portion is a third point, the tangent line of the second leading edge portion at the third point is a second tangent line, the intersection of the second leading edge portion and the outer diameter circle of the hub is a fourth point, the line connecting the fourth point and the center of the circle is a sixth line, the included angle between the sixth line and the second tangent line is A4, A4 is the sweep angle of the second leading edge portion, -55°≤A4≤0°.

[0029] In an alternative embodiment, when r / R=0.4, A4 is -1°; when r / R=0.55, A4 is -9°; when r / R=0.7, A4 is -19°; when r / R=0.85, A4 is -30°; when r / R=0.95, A4 is -39°.

[0030] In an alternative embodiment, from the first root portion to the first tip portion, the first leading edge portion sweeps in the same direction as the wind blade and the sweep angle of the first leading edge portion gradually increases.

[0031] In an alternative embodiment, the intersection of the base circle section and the first leading edge portion is a fifth point J, the tangent line of the first leading edge portion at the fifth point is a third tangent line L 10 , the intersection of the first leading edge portion and the outer diameter circle of the hub is a sixth point, the line connecting the sixth point and the center of the circle is a seventh line, the included angle between the seventh line and the third tangent line is A5, A5 is the sweep angle of the first leading edge portion, 0°≤A5≤10°.

[0032] In an alternative embodiment, when r / R=0.4, A5 is 4°; when r / R=0.55, A5 is 5°; when r / R=0.7, A5 is 6°; when r / R=0.85, A5 is 7°; when r / R=0.95, A5 is 9°.

[0033] In an alternative embodiment, on the base circle section, the cross section of the first blade is a first cross section, the cross section of the second blade is a second cross section, from the first trailing edge portion to the first leading edge portion, the first cross section sweeps in the same direction as the wind blade, from the second trailing edge portion to the second leading edge portion, the second cross section sweeps in the same direction as the wind blade.

[0034] In an alternative embodiment, on the first cross section, the line connecting the first leading edge portion and the first trailing edge portion is a first chord line, the included angle between the first chord line and the air inlet end surface of the hub is Q1, on the second cross section, the line connecting the second leading edge portion and the second trailing edge portion is a second chord line, the included angle between the second chord line and the air inlet end surface of the hub is Q2;

[0035] r / R=0.4, 35°≤Q1≤45°, 35°≤Q2≤45°;

[0036] r / R=0.55, 30°≤Q1≤35°, 30°≤Q2≤40°;

[0037] r / R=0.7, 25°≤Q1≤30°, 25°≤Q2≤35°;

[0038] r / R=0.85, 20°≤Q1≤30°, 20°≤Q2≤30°;

[0039] r / R=0.98, 15°≤Q1≤25°, 0°≤Q2≤10°.

[0040] In an alternative embodiment, the first leading edge portion is concave towards the side where the air inlet end of the hub is located, the second trailing edge portion is convex towards the side where the air outlet end of the hub is located, and the first tip portion is connected to the second tip portion.

[0041] Beneficial effects: By making the first leading edge portion concave towards the side where the air inlet end of the hub is located, the second trailing edge portion convex towards the side where the air outlet end of the hub is located, and the first tip portion connected to the second tip portion, sufficient flow area is provided between the first blade and the second blade, the airflow flows more smoothly between the double blades, the aerodynamic performance of the blades is improved, and the petal-shaped transition fitting of the double blade tips is facilitated.

[0042] In an alternative embodiment, the first trailing edge portion, the first tip portion, the second leading edge portion, and the second tip portion are provided with rounded corners, and along the rotation direction of the fan blade, the first blade is curved towards the side where the air inlet end of the hub is located from the first trailing edge portion to the first tip portion, curved towards the side where the air outlet end of the hub is located from the first tip portion to the first leading edge portion, the second blade is curved towards the side where the air inlet end of the hub is located from the second trailing edge portion to the second tip portion, and curved towards the side where the air outlet end of the hub is located from the second tip portion to the second leading edge portion.

[0043] Beneficial effects: The shape of the blade unit is more in line with the petal shape, and the appearance is more beautiful.

[0044] In an alternative embodiment, a concave portion is formed at the connection between the first tip portion and the second tip portion.

[0045] Beneficial effects: The concave portion is formed at the connection between the first tip portion and the second tip portion, the shape of the blade unit is more in line with the petal shape, and the appearance is more beautiful.

[0046] In an alternative embodiment, the first blade tip and the second blade tip are provided with a wedge-shaped connecting structure transitioning from the first suction surface to the second suction surface.

[0047] Beneficial effects: the first suction surface and the second suction surface are connected through the wedge-shaped connecting structure, which can effectively prevent the blade tip from collapsing during the blade forming, and enhance the firmness of the blade forming.

[0048] In a second aspect, the utility model also provides a fan, which comprises:

[0049] The axial flow fan blade. BRIEF DESCRIPTION OF DRAWINGS

[0050] In order to more clearly illustrate the specific embodiments of the utility model or the technical solutions in the prior art, the drawings needed to be used in the specific embodiments or the prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are some embodiments of the utility model, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0051] Figure 1 It is a front view of the axial flow fan blade of the utility model embodiment;

[0052] Figure 2 It is a structural schematic diagram of the axial flow fan blade of the utility model embodiment Figure 1 ;

[0053] Figure 3 It is a structural schematic diagram of the axial flow fan blade of the utility model embodiment Figure 2 ;

[0054] Figure 4 It is a structural schematic diagram of the axial flow fan blade of the utility model embodiment Figure 3 ;

[0055] Figure 1 It is a local schematic diagram of the axial flow fan blade of the utility model embodiment Figure 6 ;

[0056] Figure 2 It is a local schematic diagram of the axial flow fan blade of the utility model embodiment Figure 7 ;

[0057] Figure 3 It is a local schematic diagram of the axial flow fan blade of the utility model embodiment Figure 8 ;

[0058] Figure 9 It is a sectional view of the first blade and the second blade on the base circle section of the axial flow fan blade of the utility model embodiment;

[0059] Figure 1 A partial structure diagram of the axial flow fan blade Figure 10

[0060] Figure 2 A partial structure diagram of the axial flow fan blade Figure 11

[0061] Figure 10 A Figure 12 enlarged view of A in FIG.

[0062] Figures 1 to 12 A schematic diagram of simulation of the fan blade and the traditional fan blade.

[0063] BRIEF DESCRIPTION OF DRAWINGS

[0064] 1, first blade; 101, first blade root; 102, first blade tip; 103, first leading edge; 104, first trailing edge; 105, first suction surface; 106, first pressure surface; 107, first cross section; 2, second blade; 201, second blade root; 202, second blade tip; 203, second leading edge; 204, second trailing edge; 205, second suction surface; 206, second pressure surface; 207, second cross section; 3, hub; 301, air inlet end; 302, air outlet end; 4, recess; 5, wedge-shaped connecting structure;

[0065] O, center; B1, chord midpoint of the first blade root; B2, chord midpoint of the second blade root; C1, chord midpoint of the first blade; C2, chord midpoint of the second blade; E, first point; H, second point; G, third point; F, fourth point; J, fifth point; I, sixth point;

[0066] L2, first connecting line; L1, second connecting line; L3, third connecting line; L4, first tangent line; L6, fourth connecting line; L5, fifth connecting line; L8, second tangent line; L7, sixth connecting line; L 10 , third tangent line; L9, seventh connecting line; b1, first chord line; b2, second chord line. DETAILED DESCRIPTION

[0067] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme of the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are some embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0068] ​​The fan in the related art adopts a traditional axial flow fan blade, the blade design thereof is usually a straight blade or a spiral blade, the traditional blade modeling is limited, and no breakthrough has been made in appearance for many years, which easily causes consumer aesthetic fatigue and reduces product sales; secondly, although the traditional fan blade aerodynamic design can meet basic air supply requirements, there are deficiencies in air flow efficiency, noise control and the like, the traditional fan blade design greatly influences air flow paths, vortexes are easily generated at blade tips and blade trailing edges, which leads to energy loss and noise increase; in addition, the traditional fan blade is usually a single blade design, and is easily deformed and collapsed at a weak structure position of the blade tip during molding due to influences of materials and injection molding processes, which changes the aerodynamic performance of the fan blade, and often causes injection molding performance errors in product development processes, which brings difficulties to scheme confirmation and motor matching.

[0069] The embodiments of the present application are described below in combination with Figures 1 to 6 , the embodiments of the present application.

[0070] According to the embodiments of the present application, on the one hand, an axial flow fan blade is provided, which comprises: a plurality of blade units distributed in a circumferential direction, each blade unit comprising a first blade 1 and a second blade 2.

[0071] The first blade 1 comprises a first blade root portion 101, a first blade tip portion 102, a first leading edge portion 103, a first trailing edge portion 104, a first suction surface 105 and a first pressure surface 106; the second blade 2 comprises a second blade root portion 201, a second blade tip portion 202, a second leading edge portion 203, a second trailing edge portion 204, a second suction surface 205 and a second pressure surface 206, and the second trailing edge portion 204 is connected with the first leading edge portion 103.

[0072] In the embodiments, each blade unit is composed of the first blade 1 and the second blade 2 in a double-blade fitting manner, the structure of the blade unit is novel, the appearance is beautiful, the blade unit is closer to a petal shape, and the aerodynamic performance of the fan can be improved due to the fact that each blade unit is composed of the first blade 1 and the second blade 2.

[0073] Specifically, in an embodiment, the number of blade units is n, and n is greater than or equal to 3, and n is selected as 5 in the embodiment, so that the blade unit modeling is closer to a petal shape.

[0074] It should be noted that the first blade 1 and the second blade 2 are arranged in the same direction along the rotation direction of the fan blade.

[0075] Specifically, in combination with Figure 9 , Figure 10 and Figure 6 , the axial flow fan blade rotates in a clockwise direction, and each blade unit is sequentially the second blade 2, the first blade 1 in the clockwise direction.

[0076] The first suction surface 105 refers to the windward side of the first blade 1, the first pressure surface 106 refers to the leeward side of the first blade 1, the second suction surface 205 refers to the windward side of the second blade 2, and the second pressure surface 206 refers to the leeward side of the second blade 2.

[0077] In one embodiment, the axial flow fan blade includes a hub 3, and the blade unit is arranged on the hub 3. The outer diameter of the blade unit is D, the diameter of the hub 3 is d, and 0.2≤d / D≤0.35.

[0078] In this embodiment, d / D refers to the hub 3 ratio, which is an important design parameter of the axial flow fan. If the hub 3 ratio is too large, the efficiency of the fan will be reduced, and the aerodynamic performance of the whole machine will be reduced. On the contrary, if the hub 3 ratio of the axial flow fan is too small, flow separation will occur at the blade root of the fan blade, causing performance loss of the fan blade. Therefore, by making the hub 3 ratio between 0.2 and 0.35, the efficiency of the fan can be ensured, and the aerodynamic performance of the whole machine can be improved.

[0079] In a specific embodiment, the hub 3 ratio is 0.2.

[0080] In a specific embodiment, the hub 3 ratio is 0.24.

[0081] In a specific embodiment, the hub 3 ratio is 0.35.

[0082] In one embodiment, from the first trailing edge 104 to the first leading edge 103, the first tip portion 102 is swept in the same direction as the rotation direction of the fan blade, and the net sweep angle gradually increases.

[0083] In this embodiment, from the first trailing edge 104 to the first leading edge 103, the first tip portion 102 is swept in the same direction as the rotation direction of the fan blade, and the net sweep angle gradually increases, which can increase the flow guiding tendency of the first blade 1, reduce the double-blade disturbance, and facilitate the fitting of the first blade 1 and the second blade 2.

[0084] In one embodiment, the maximum outer edge radius of the blade unit is R, an axial cylindrical base circle section with a radius r is made with the center O of the hub 3 as the base point, the line connecting the center O and the chord midpoint B1 of the first blade root portion is the first line L2, the line connecting the chord midpoint C1 of the first blade at the base circle section and the center O is the second line L1, the included angle between the first line L2 and the second line L1 is A1, and A1 is the net sweep angle of the first blade 1. From the first blade root portion 101 to the first tip portion 102, A1 gradually increases.

[0085] In this embodiment, from the first blade root portion 101 to the first tip portion 102, the net sweep angle of the first blade 1 gradually increases, which can increase the flow guiding tendency of the first blade 1 and reduce the double-blade disturbance.

[0086] It should be noted that A1 gradually increases from the first blade root 101 to the first blade tip 102, which actually makes the second connecting line L1 gradually move away from the first connecting line L2 in the clockwise direction from the first blade root 101 to the first blade tip 102, and thus makes the first blade tip 102 sweep in the same direction as the rotation direction of the fan blade from the first trailing edge 104 to the first leading edge 103, and the sweep angle gradually increases.

[0087] In one embodiment, 0°≤A1≤15°.

[0088] In one embodiment, A1 is 1° when r / R=0.4, 4° when r / R=0.55, 6° when r / R=0.7, 9° when r / R=0.85, and 10° when r / R=0.95.

[0089] In one embodiment, the first trailing edge 104 sweeps in the same direction as the rotation direction of the fan blade from the first blade root 101 to the first blade tip 102, and the sweep angle of the first trailing edge 104 gradually increases.

[0090] In this embodiment, since the blade trailing edge shape affects the blade surface working area and the blade surface pressure gradient distribution, when the blade surface airflow passes through the blade trailing edge, local pressure pulsation force is easily generated due to the vortex shedding of the trailing vortex, forming vortex noise. By making the first trailing edge 104 sweep in the same direction as the rotation direction of the fan blade and the sweep angle of the first trailing edge 104 gradually increase, the vortex shedding of the first trailing edge 104 can be reduced.

[0091] In one embodiment, the intersection of the first trailing edge 104 and the outer diameter circle of the hub 3 is a second point H, the connecting line between the second point H and the center O is a third connecting line L3, the intersection of the base circle cross section and the first trailing edge 104 is a first point E, the tangent line of the first trailing edge 104 at the first point E is a first tangent line L4, and the included angle between the third connecting line L3 and the first tangent line L4 is A2. A2 is the sweep angle of the first trailing edge 104, and 0°≤A2≤55°.

[0092] In this embodiment, by making 0°≤A2≤55°, the vortex shedding of the first trailing edge 104 can be reduced, and the first blade 1 can meet the petal appearance.

[0093] In one embodiment, A2 is 9° when r / R=0.4, 13° when r / R=0.55, 26° when r / R=0.7, 35° when r / R=0.85, and 41° when r / R=0.95.

[0094] In this embodiment, the vortex shedding of the first trailing edge 104 can be reduced, and the first blade 1 can meet the petal appearance.

[0095] In one embodiment, the second tip portion 202 is swept against the wind-rotor rotation direction from the second trailing edge 204 to the second leading edge 203, and the net sweep angle gradually increases.

[0096] In this embodiment, the second tip portion 202 is swept against the wind-rotor rotation direction from the second trailing edge 204 to the second leading edge 203, and the net sweep angle gradually increases, which can increase the flow guiding tendency of the second blade 2, reduce the double-blade disturbance, and facilitate the fitting of the second blade 2.

[0097] In one embodiment, the line connecting the center O and the chord midpoint B2 of the second blade root is the fourth line L6, the line connecting the chord midpoint C2 of the second blade at the base circle section and the center O is the fifth line L5, the included angle between the fourth line L6 and the fifth line L5 is A3, and A3 is the net sweep angle of the second blade 2, which gradually increases from the second blade root 201 to the second tip portion 202.

[0098] In this embodiment, the net sweep angle of the second blade 2 gradually increases from the second blade root 201 to the second tip portion 202, which can increase the flow guiding tendency of the second blade 2 and reduce the double-blade disturbance.

[0099] It should be noted that A3 gradually increases from the second blade root 201 to the second tip portion 202, which actually makes the fifth line L5 gradually move away from the second line L1 in the counterclockwise direction from the second blade root 201 to the second tip portion 202, and thus the second tip portion 202 is swept against the wind-rotor rotation direction from the second trailing edge 204 to the second leading edge 203, and the net sweep angle gradually increases.

[0100] In one embodiment, -15°≤A3≤0°.

[0101] It should be noted that A3 being negative means that the fifth line L5 is located on the counterclockwise side of the fourth line L6, and in combination with Figure 6 , the fifth line L5 is located on the left side of the fourth line L6.

[0102] In one embodiment, when r / R=0.4, A3 is 0°; when r / R=0.55, A3 is -3°; when r / R=0.7, A3 is -5°; when r / R=0.85, A3 is -6°; and when r / R=0.95, A3 is -8°.

[0103] In one embodiment, the second leading edge 203 is swept against the wind-rotor rotation direction from the second blade root 201 to the second tip portion 202, and the sweep angle of the second leading edge 203 gradually increases.

[0104] In this embodiment, the second leading edge portion 203 is curved and swept in a direction opposite to the rotation direction of the blade, and the curved and swept angle of the second leading edge portion 203 gradually increases, which conforms to the shape of a petal and makes the appearance more beautiful.

[0105] In one embodiment, the intersection of the base circle section and the second leading edge portion 203 is a third point G, the tangent line of the second leading edge portion 203 at the third point G is a second tangent line L8, the intersection of the second leading edge portion 203 and the outer diameter circle of the hub 3 is a fourth point F, the line connecting the fourth point F and the center O is a sixth line L7, the included angle between the sixth line L7 and the second tangent line L8 is A4, and A4 is the curved and swept angle of the second leading edge portion 203, -55°≤A4≤0°.

[0106] In this embodiment, the curved and swept angle of the second leading edge portion 203 is between -55° and 0°, which conforms to the shape of a petal and makes the appearance more beautiful.

[0107] It should be noted that the negative value of A4 represents that the second tangent line L8 is located on the side opposite to the sixth line L7 in the counterclockwise direction, and in combination with Figure 12 , the second tangent line L8 is located on the left side of the sixth line L7.

[0108] In one embodiment, when r / R=0.4, A4 is -1°; when r / R=0.55, A4 is -9°; when r / R=0.7, A4 is -19°; when r / R=0.85, A4 is -30°; and when r / R=0.95, A4 is -39°.

[0109] In this embodiment, the shape of the second leading edge portion 203 conforms to the shape of a petal, and the appearance is more beautiful.

[0110] In one embodiment, from the first blade root portion 101 to the first blade tip portion 102, the first leading edge portion 103 is curved and swept in a direction consistent with the rotation direction of the blade, and the curved and swept angle of the first leading edge portion 103 gradually increases.

[0111] In this embodiment, since the first blade 1 is located behind the second blade 2 when the axial flow blade rotates in the clockwise direction, the blade tag surface airflow is more or less affected by the second trailing edge portion 204, thereby affecting the working efficiency of the first blade 1. Therefore, the first leading edge portion 103 is curved and swept in a direction consistent with the rotation direction of the blade, and the curved and swept angle of the first leading edge portion 103 gradually increases, which can increase the flow guiding tendency of the first blade 1 and reduce the double-leaf turbulence influence.

[0112] In one embodiment, the intersection of the base circle section and the first leading edge portion 103 is a fifth point J, the tangent line of the first leading edge portion 103 at the fifth point J is a third tangent line L 10 , the intersection of the first leading edge portion 103 and the outer diameter circle of the hub 3 is a sixth point I, the line connecting the sixth point I and the center O is a seventh line L9, and the included angle between the seventh line L9 and the third tangent line L10 The included angle between the first leading edge portion 103 and the first trailing edge portion 104 is A5, and A5 is the sweep angle of the first leading edge portion 103, 0°≤A5≤10°.

[0113] In this embodiment, by setting the sweep angle of the first leading edge portion 103 between 0° and 10°, the fitting of the first blade 1 and the second blade 2 is facilitated.

[0114] In one embodiment, when r / R=0.4, A5 is 4°; when r / R=0.55, A5 is 5°; when r / R=0.7, A5 is 6°; when r / R=0.85, A5 is 7°; and when r / R=0.95, A5 is 9°.

[0115] In one embodiment, on the base circle section, the cross section of the first blade 1 is the first cross section 107, and the cross section of the second blade 2 is the second cross section 207. From the first trailing edge portion 104 to the first leading edge portion 103, the first cross section 107 is swept in the same direction as the rotation direction of the fan blade, and from the second trailing edge portion 204 to the second leading edge portion 203, the second cross section 207 is swept in the same direction as the rotation direction of the fan blade.

[0116] In this embodiment, by sweeping the first cross section 107 in the same direction as the rotation direction of the fan blade from the first trailing edge portion 104 to the first leading edge portion 103, and sweeping the second cross section 207 in the same direction as the rotation direction of the fan blade from the second trailing edge portion 204 to the second leading edge portion 203, the flow guiding tendency can be increased, and the airflow can flow more smoothly.

[0117] In one embodiment, on the first cross section 107, the line connecting the first leading edge portion 103 and the first trailing edge portion 104 is the first chord line b1, and the included angle between the first chord line b1 and the end surface of the air inlet end 301 of the hub 3 is Q1. On the second cross section 207, the line connecting the second leading edge portion 203 and the second trailing edge portion 204 is the second chord line b2, and the included angle between the second chord line b2 and the end surface of the air inlet end 301 of the hub 3 is Q2.

[0118] When r / R=0.4, 35°≤Q1≤45°, and 35°≤Q2≤45°;

[0119] When r / R=0.55, 30°≤Q1≤35°, and 30°≤Q2≤40°;

[0120] When r / R=0.7, 25°≤Q1≤30°, and 25°≤Q2≤35°;

[0121] When r / R=0.85, 20°≤Q1≤30°, and 20°≤Q2≤30°;

[0122] When r / R=0.98, 15°≤Q1≤25°, and 0°≤Q2≤10°.

[0123] In one specific embodiment, when r / R = 0.4, Q1 = 36.2°, Q2 ≤ 36.2°;

[0124] When r / R = 0.55, Q1 = 30.6°, Q2 ≤ 33.5°;

[0125] When r / R = 0.7, Q1 = 26.8°, Q2 ≤ 29.9°;

[0126] When r / R = 0.85, Q1 = 23.7°, Q2 ≤ 23.3°;

[0127] When r / R = 0.98, Q1 = 20.4°, Q2 ≤ 7°.

[0128] In one embodiment, the first leading edge 103 is recessed toward the side where the air inlet end 301 of the hub 3 is located, the second trailing edge 204 is arched toward the side where the air outlet end 302 of the hub 3 is located, and the top of the first blade 102 is connected to the top of the second blade 202.

[0129] In this embodiment, by making the first leading edge 103 recessed toward the side where the air inlet end 301 of the hub 3 is located, and the second trailing edge 204 arched toward the side where the air outlet end 302 of the hub 3 is located, and the first blade tip 102 is connected to the second blade tip 202, sufficient flow area can be provided between the first blade 1 and the second blade 2, making the airflow between the two blades smoother, improving the aerodynamic performance of the blades, and at the same time facilitating the transition fitting of the petal shape of the blade tips.

[0130] In one embodiment, the first trailing edge 104, the first blade tip 102, the second leading edge 203, and the second blade tip 202 are provided with rounded corners. Along the direction of the blade rotation, from the first trailing edge 104 to the first blade tip 102, the first blade 1 bends toward the side where the air inlet end 301 of the hub 3 is located. From the first blade tip 102 to the first leading edge 103, the first blade 1 bends toward the side where the air outlet end 302 of the hub 3 is located. From the second trailing edge 204 to the second blade tip 202, the second blade 2 bends toward the side where the air inlet end 301 of the hub 3 is located. From the second blade tip 202 to the second leading edge 203, the second blade 2 bends toward the side where the air outlet end 302 of the hub 3 is located.

[0131] In this embodiment, the shape of the leaf unit is more in line with the shape of a petal, making it more aesthetically pleasing.

[0132] In one embodiment, a recess 4 is formed at the junction of the top 102 of the first leaf and the top 202 of the second leaf.

[0133] In this embodiment, a recess 4 is formed at the junction of the top 102 of the first leaf and the top 202 of the second leaf, and the shape of the leaf unit is more in line with the shape of the petal, making the appearance more beautiful.

[0134] In one embodiment, the first blade tip 102 and the second blade tip 202 are provided with a wedge-shaped connecting structure 5 which is connected by the first suction surface 105 to the second suction surface 205.

[0135] In this embodiment, the first suction surface 105 and the second suction surface 205 are connected by the wedge-shaped connecting structure 5, which can effectively prevent the blade tip from collapsing during the blade forming process and enhance the firmness of the blade forming process.

[0136] In a specific embodiment, the curvature of the wedge-shaped connecting structure 5 is consistent with the curvature of the second blade tip 202, which can reduce the influence of the airflow on the wedge-shaped connecting structure 5.

[0137] In combination Blade configuration , the axial flow fan provided in the embodiment can effectively reduce the vortex shedding of the blade at the blade tip and the trailing edge, thereby reducing the vortex noise of the blade, and can effectively improve the aerodynamic loss caused by the airflow separation of the blade surface, and improve the air volume performance of the fan, as shown in the following table, compared with the conventional fan, the noise and air volume performance of the fan provided in the embodiment are significantly improved.

[0138] Air volume (m3 / min) Noise (dB) Conventional blade Blade of the present embodiment 41 61 ​ 47 59

[0139] According to the embodiments of the present application, on the other hand, a fan is also provided, which comprises the axial flow fan provided in the above embodiments.

[0140] Although the embodiments of the present application are described in combination with the drawings, various modifications and variations can be made by those skilled in the art without departing from the spirit and scope of the present application, and such modifications and variations all fall within the scope defined by the present application.

Claims

1. An axial flow impeller, characterized by, The axial flow fan blade comprises: a plurality of circumferentially spaced blade units, each blade unit comprising: a first blade (1) comprising a first blade root (101), a first blade tip (102), a first leading edge (103), a first trailing edge (104), a first suction surface (105), and a first pressure surface (106); a second blade (2) comprising a second blade root (201), a second blade tip (202), a second leading edge (203), a second trailing edge (204), a second suction surface (205), and a second pressure surface (206), the second trailing edge (204) being connected to the first leading edge (103).

2. The axial fan blade of claim 1, wherein, The axial flow fan blade comprises a hub (3), the blade units are arranged on the hub (3), the outer diameter of the blade units is D, the diameter of the hub (3) is d, and 0.2≤d / D≤0.

35.

3. The axial fan blade of claim 2, wherein, From the first trailing edge (104) to the first leading edge (103), the first blade tip (102) is swept in the same direction as the rotation direction of the fan blade, and the sweep angle gradually increases.

4. The axial fan blade of claim 3, wherein, The maximum outer edge radius of the blade unit is R, an axial cylindrical base circle section with a radius r is made with the center (O) of the hub (3) as the base point, the line connecting the center (O) and the chord midpoint (B1) of the first blade root is the first line (L2), the line connecting the chord midpoint (C1) of the first blade and the center (O) at the base circle section is the second line (L1), the included angle between the first line (L2) and the second line (L1) is A1, A1 is the sweep angle of the first blade (1), and A1 gradually increases from the first blade root (101) to the first blade tip (102).

5. The axial fan blade of claim 4, wherein, 0°≤A1≤15°。 6. The axial fan blade of claim 4, wherein, When r / R=0.4, A1 is 1°; when r / R=0.55, A1 is 4°; when r / R=0.7, A1 is 6°; when r / R=0.85, A1 is 9°; and when r / R=0.95, A1 is 10°.

7. The axial fan blade of claim 4, wherein, From the first blade root (101) to the first blade tip (102), the first trailing edge (104) is swept in the same direction as the rotation direction of the fan blade, and the sweep angle of the first trailing edge (104) gradually increases.

8. The axial fan blade of claim 7, wherein, The intersection of the first trailing edge (104) and the outer diameter circle of the hub (3) is the second point (H), the line connecting the second point (H) and the center (O) is the third line (L3), the intersection of the base circle section and the first trailing edge (104) is the first point (E), the tangent line of the first trailing edge (104) at the first point (E) is the first tangent line (L4), the included angle between the third line (L3) and the first tangent line (L4) is A2, A2 is the sweep angle of the first trailing edge (104), and 0°≤A2≤55°.

9. The axial fan blade of claim 8, wherein, When r / R=0.4, A2 is 9°; when r / R=0.55, A2 is 13°; when r / R=0.7, A2 is 26°; when r / R=0.85, A2 is 35°; and when r / R=0.95, A2 is 41°.

10. An axial fan blade according to any one of claims 4 to 9, wherein, From the second trailing edge (204) to the second leading edge (203), the tip of the second blade (202) bends in the opposite direction to the blade rotation, and the net bending angle gradually increases.

11. The axial fan blade of claim 10, wherein, The line connecting the center (O) and the midpoint (B2) of the chord at the root of the second blade is the fourth line (L6). The line connecting the midpoint (C2) of the chord of the second blade at the base circle section and the center (O) is the fifth line (L5). The angle between the fourth line (L6) and the fifth line (L5) is A3. A3 is the net bending angle of the second blade (2). A3 gradually increases from the root (201) of the second blade to the top (202) of the second blade.

12. The axial fan blade of claim 11, wherein, -15°≤A3≤0°。 13. The axial fan blade of claim 11, wherein, When r / R = 0.4, A3 is 0°; when r / R = 0.55, A3 is -3°; when r / R = 0.7, A3 is -5°; when r / R = 0.85, A3 is -6°; when r / R = 0.95, A3 is -8°.

14. An axial fan blade according to any one of claims 4 to 9, 11 to 13, wherein, From the root (201) of the second blade to the tip (202) of the second blade, the second leading edge (203) sweeps against the direction of the blade rotation and the sweep angle of the second leading edge (203) gradually increases.

15. The axial fan blade of claim 14, wherein, The intersection of the base circle section and the second leading edge (203) is the third point (G). The tangent of the second leading edge (203) at the third point (G) is the second tangent (L8). The intersection of the second leading edge (203) and the outer diameter circle of the hub (3) is the fourth point (F). The line connecting the fourth point (F) and the center (O) is the sixth line (L7). The angle between the sixth line (L7) and the second tangent (L8) is A4. A4 is the sweep angle of the second leading edge (203), -55°≤A4≤0°.

16. The axial fan blade of claim 15, wherein, When r / R = 0.4, A4 is -1°; when r / R = 0.55, A4 is -9°; when r / R = 0.7, A4 is -19°; when r / R = 0.85, A4 is -30°; when r / R = 0.95, A4 is -39°.

17. An axial fan blade according to any one of claims 4 to 9, 11 to 13, 15 to 16, wherein, From the root (101) of the first leaf to the tip (102) of the first leaf, the first leading edge (103) bends in a direction consistent with the direction of the blade rotation and the bend angle of the first leading edge (103) gradually increases.

18. The axial fan blade of claim 17, wherein, The intersection of the base circle section and the first front edge portion (103) is a fifth point (J), and a tangent line of the first front edge portion (103) at the fifth point (J) is a third tangent line (L 10 ), the intersection of the first front edge portion (103) and the outer diameter circle of the hub (3) is a sixth point (I), the line connecting the sixth point (I) and the center (O) of the circle is a seventh line (L9), the included angle between the seventh line (L9) and the third tangent line (L 10 ) is A5, and A5 is the sweep angle of the first front edge portion (103), 0°≤A5≤10°.

19. The axial fan blade of claim 18, wherein, When r / R = 0.4, A5 is 4°; when r / R = 0.55, A5 is 5°; when r / R = 0.7, A5 is 6°; when r / R = 0.85, A5 is 7°; when r / R = 0.95, A5 is 9°.

20. The axial fan blade according to any one of claims 4 to 9, 11 to 13, 15 to 16, 18 to 19, characterized in that, On the base circle cross section, the cross section of the first blade (1) is the first cross section (107), and the cross section of the second blade (2) is the second cross section (207). From the first trailing edge (104) to the first leading edge (103), the first cross section (107) sweeps in the same direction as the blade rotation direction. From the second trailing edge (204) to the second leading edge (203), the second cross section (207) sweeps in the same direction as the blade rotation direction.

21. The axial fan blade of claim 20, wherein, The first chord line (b1) between the first leading edge (103) and the first trailing edge (104) and the angle between the first chord line (b1) and the end face of the air inlet end (301) of the hub (3) is Q1, and the second chord line (b2) between the second leading edge (203) and the second trailing edge (204) and the angle between the second chord line (b2) and the end face of the air inlet end (301) of the hub (3) is Q2. When r / R=0.4, 35°≤Q1≤45°, and 35°≤Q2≤45°; When r / R=0.55, 30°≤Q1≤35°, and 30°≤Q2≤40°; When r / R=0.7, 25°≤Q1≤30°, and 25°≤Q2≤35°; When r / R=0.85, 20°≤Q1≤30°, and 20°≤Q2≤30°; When r / R=0.98, 15°≤Q1≤25°, and 0°≤Q2≤10°.

22. The axial fan blade according to any one of claims 1 to 9, 11 to 13, 15 to 16, 18 to 19, 21, characterized in that, The first leading edge (103) is recessed to the side where the air inlet end (301) of the hub (3) is located, and the second trailing edge (204) is arched to the side where the air outlet end (302) of the hub (3) is located.

23. The axial fan blade of claim 22, wherein, The first trailing edge (104), the first tip (102), the second leading edge (203), and the second tip (202) are provided with a round corner, and along the rotation direction of the blade, from the first trailing edge (104) to the first tip (102), the first blade (1) is curved to the side where the air inlet end (301) of the hub (3) is located, from the first tip (102) to the first leading edge (103), the first blade (1) is curved to the side where the air outlet end (302) of the hub (3) is located, from the second trailing edge (204) to the second tip (202), the second blade (2) is curved to the side where the air inlet end (301) of the hub (3) is located, and from the second tip (202) to the second leading edge (203), the second blade (2) is curved to the side where the air outlet end (302) of the hub (3) is located.

24. The axial fan blade of claim 23, wherein, The first tip (102) and the second tip (202) are connected to form a recess (4).

25. The axial fan blade of claim 22, wherein, The first tip (102) and the second tip (202) are provided with a wedge-shaped connecting structure (5) transitioning from the first suction surface (105) to the second suction surface (205).

26. A fan, comprising: The axial flow fan blade according to any one of claims 1-25. The axial flow fan blade according to any one of claims 1-25.

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