Axial-flow fan blade and air conditioning device

Abstract

The invention relates to the technical field of household appliances, and discloses an axial flow fan blade and an air conditioning device. The multiple blade units are connected to the hub and distributed in the circumferential direction of the hub at intervals, and each blade unit comprises a first blade and a second blade; the first blade comprises a first blade root part, a first blade top part, a first front edge part and a first tail edge part; the second blade comprises a second blade root part, a second blade top part, a second front edge part and a second tail edge part, the second tail edge part is connected with the first front edge part, and the first blade top part and the second blade top part are in a bent arch shape and are arched in the direction away from the hub. According to the axial flow fan blade, the defects that in the related technology, energy loss and noise are large in the using process of the fan blade, and aesthetic fatigue of a user is likely to be caused can be overcome.

Description

Technical Field

[0001] The present invention relates to the technical field of household appliances, and particularly relates to an axial-flow impeller and an air-conditioning device. Background Art

[0002] In an air-conditioning device such as an air conditioner and an air purifier, an impeller is generally provided. The impeller generates an air flow by rotation, so that the air flows along the direction of the fan shaft.

[0003] The design of the impeller has a great influence on the air flow path. In the related art, the blade structure includes a plurality of blades provided on the circumferential side surface of the hub. An air passing hole is formed on each blade or between each blade and the hub. The blade includes at least two rectifying segments on the periphery of the air passing hole. The suction surface of one rectifying segment is connected to the pressure surface of the other rectifying segment. However, the tip width of such a blade is relatively narrow, and vortices are likely to be generated at the tip and the trailing edge of the blade, resulting in energy loss and increased noise. Moreover, the shape of such a blade is limited, which is likely to cause aesthetic fatigue of users. Summary of the Invention

[0004] In view of this, the present invention provides an axial-flow impeller and an air-conditioning device to solve the defects in the related art that the impeller has large energy loss and noise during use and is likely to cause aesthetic fatigue of users.

[0005] In a first aspect, the present invention provides an axial-flow impeller, including: a hub; a plurality of blade units connected to the hub and distributed at intervals along the circumferential direction of the hub. Each blade unit includes a first blade and a second blade; the first blade includes a first blade root, a first blade top, a first leading edge and a first trailing edge; the second blade includes a second blade root, a second blade top, a second leading edge and a second trailing edge. The second trailing edge is connected to the first leading edge. The first blade top and the second blade top are arched and arched away from the hub.

[0006] Beneficial effects: The blade unit of the axial-flow impeller according to the embodiment of the present invention is composed of a first blade and a second blade. By means of double-blade fitting, the blade top of each blade unit forms an "M"-shaped arched shape, making the shape of the blade closer to the petal shape, improving the aesthetics of the axial-flow impeller, breaking the aesthetic fatigue of users for the axial-flow impeller, and increasing the visual attraction of the product.

[0007] On this basis, since the blade unit of the axial-flow fan blade of the present application is formed by fitting a first blade and a second blade, the tip width of the blade unit can be extended, thereby delaying the formation length of the airflow in the tip region, reducing the scale and magnitude when the airflow detaches from the tip region, and further reducing the discrete noise generated when the axial-flow fan blade rotates. Therefore, the axial-flow fan blade implemented in the present application can reduce the vortex detachment at the top and trailing edge of the blade, thereby reducing the vortex noise of the blade.

[0008] Therefore, the axial-flow fan blade of the present application can overcome the defects in the related art that the energy loss and noise of the fan blade are large during use, and it is easy to cause aesthetic fatigue of users.

[0009] In an optional implementation manner, the first blade top and the second blade top are connected at the middle position of the blade unit.

[0010] In an optional implementation manner, the maximum outer edge radius of the blade unit is R;

[0011] The intersection point between the first blade top and the first trailing edge is the first point, and the distance between the first point and the center of the hub is R', 0.95 > R' / R > 0.75; and / or,

[0012] The intersection point between the second blade top and the second leading edge is the second point, and the distance between the second point and the center of the hub is R', 0.95 > R' / R > 0.75.

[0013] Beneficial effect: Taking the center O of the blade hub as the base point, different axial cylindrical base circle sections with a radius of r are made. When the part of the blade intercepted by the base circle section is the top of the fan blade, the axial projection curve of the base circle section with a radius of R' is the dividing line of the top of the fan blade. When the top of the blade is in the above area, it can ensure that the shape of the axial-flow fan blade is closer to the petal shape and does not affect the overall aerodynamic performance of the blade unit.

[0014] In an optional implementation manner, the intersection point between the first blade top and the first trailing edge is the first point, and the intersection point between the first blade top and the second blade top is the third point. Taking the center of the hub as the base point, an axial cylindrical base circle section with a radius of r is made. The connection line between the center and the first point is the first connection line, and the connection line between the center and the third point is the second connection line. The included angle between the first connection line and the second connection line is θ1; the top of the first blade arches away from the hub to form a first inflection point, the first inflection point and the center of the hub; and / or,

[0015] The intersection point between the top of the second blade and the second leading edge is the second point, and the intersection point between the top of the first blade and the top of the second blade is the third point. Taking the center of the hub as the base point, an axial cylindrical base circle section with a radius of r is made. The line connecting the center and the second point is the fourth line, and the line connecting the center and the third point is the second line. The top of the second blade arches away from the hub and forms a second inflection point. The line connecting the center and the second inflection point is the fifth line. The included angle between the fifth line and the fourth line is θM2, and 0.3 ≤ θM2 / θ2 ≤ 0.7.

[0016] In an alternative embodiment, the outer diameter of the blade unit is D, and the diameter of the hub is d, where 0.2 ≤ d / D ≤ 0.35.

[0017] Beneficial effects: In this embodiment, d / D refers to the hub ratio, which is an important design parameter of the axial flow fan. If the hub ratio is too large, the efficiency of the fan will decrease, reducing the aerodynamic performance of the whole machine. On the contrary, if the hub ratio of the axial flow fan is too small, airflow separation will occur at the root of the fan blade, resulting in performance loss of the blade. Therefore, in this embodiment, by setting the hub 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.

[0018] In an alternative embodiment, from the first trailing edge to the first leading edge, the top of the first blade is swept along the direction consistent with the rotation direction of the axial flow blade, and the net sweep angle gradually increases.

[0019] Beneficial effects: In this embodiment, from the first trailing edge to the first leading edge, the top of the first blade is swept along the direction consistent with the rotation direction of the blade, and the net sweep angle gradually increases, which can increase the flow guiding trend of the first blade, reduce the influence of double-blade flow interference, and facilitate the fitting of the first blade and the second blade.

[0020] In an alternative embodiment, the maximum outer radius of the blade unit is R. Taking the center of the hub as the base point, an axial cylindrical base circle section with a radius of r is made. The line connecting the center and the midpoint of the chord of the first blade root is the sixth line, and the line connecting the midpoint of the chord of the first blade at the base circle section and the center is the seventh line. The included angle between the sixth line and the seventh line is A1, and A1 is the net sweep angle of the first blade. From the first blade root to the first blade top, A1 gradually increases.

[0021] Beneficial effects: From the first blade root to the first blade top, the net sweep angle of the first blade gradually increases, which can increase the flow guiding trend of the first blade and reduce the influence of double-blade flow interference.

[0022] It should be noted that from the root of the first blade to the top of the first blade, A1 gradually increases. In fact, from the root of the first blade to the top of the first blade, the seventh connecting line gradually moves away from the sixth connecting line in the clockwise direction. Therefore, overall, from the first trailing edge to the first leading edge, the top of the first blade is bent and swept in the direction consistent with the rotation direction of the wind blade, and the net bending angle gradually increases.

[0023] In an alternative embodiment, 0° ≤ A1 ≤ 15°.

[0024] 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 = 0.8, A1 is 9°.

[0025] In an alternative embodiment, from the root of the first blade to the top of the first blade, the first trailing edge is bent and swept in the direction consistent with the rotation direction of the axial flow wind blade, and the bending angle of the first trailing edge gradually increases.

[0026] Beneficial effect: In this embodiment, since the shape of the blade trailing edge affects the working area on the blade surface and the distribution of the pressure gradient on the blade surface, when the airflow on the blade surface flows through the blade trailing edge, local pressure pulsating force is easily generated due to the shedding of the wake vortex, forming vortex noise. By bending the first trailing edge in the direction consistent with the rotation direction of the wind blade and gradually increasing the bending angle of the first trailing edge, the vortex shedding at the first trailing edge can be reduced.

[0027] In an alternative embodiment, the intersection point of the first trailing edge and the outer diameter circle of the hub is the fifth point, the connecting line between the fifth point and the center of the circle is the eighth connecting line, the intersection point of the base circle section and the first trailing edge is the fourth point, the tangent line of the first trailing edge at the fourth point is the first tangent line, and the included angle between the eighth connecting line and the first tangent line is A2. A2 is the bending angle of the first trailing edge, and 0° ≤ A2 ≤ 55°.

[0028] 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 = 0.8, A2 is 41°.

[0029] Beneficial effect: In this embodiment, the vortex shedding at the first trailing edge can be reduced, and the first blade can meet the petal appearance shape.

[0030] In an alternative embodiment, from the second trailing edge to the second leading edge, the top of the second blade is bent and swept in the reverse direction of the rotation of the wind blade, and the net bending angle gradually increases.

[0031] Beneficial effects: In this embodiment, from the second trailing edge portion to the second leading edge portion, the second blade top is bent and swept in a direction opposite to the rotation direction of the wind blade, and the net bending angle gradually increases, which can increase the drainage trend of the second blade, reduce the influence of double-blade turbulence, and facilitate the fitting of the second blade and the second blade.

[0032] In an alternative embodiment, the line connecting the center of the circle and the chord midpoint of the second blade root is the ninth connecting line, the line connecting the chord midpoint of the second blade at the base circle section and the center of the circle is the tenth connecting line, and the angle between the ninth connecting line and the tenth connecting line is A3. A3 is the net bending angle of the second blade, and A3 gradually increases from the second blade root to the second blade top.

[0033] Beneficial effects: In this embodiment, from the second blade root to the second blade top, the net bending angle of the second blade gradually increases, which can increase the drainage trend of the second blade and reduce the influence of double-blade turbulence.

[0034] It should be noted that as A3 gradually increases from the second blade root to the second blade top, in fact, the tenth connecting line gradually moves away from the seventh connecting line in the counterclockwise direction from the second blade root to the second blade top. Therefore, as a whole, from the second trailing edge portion to the second leading edge portion, the second blade top is bent and swept in a direction opposite to the rotation direction of the wind blade, and the net bending angle gradually increases.

[0035] In an alternative embodiment, -15° ≤ A3 ≤ 0°.

[0036] 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 = 0.8, A3 is -7°.

[0037] In an alternative embodiment, from the second blade root to the second blade top, the second leading edge portion is bent and swept in a direction opposite to the rotation direction of the wind blade, and the bending angle of the second leading edge portion gradually increases.

[0038] Beneficial effects: The second leading edge portion is bent and swept in a direction opposite to the rotation direction of the wind blade, and the bending angle of the second leading edge portion gradually increases, which conforms to the shape of a petal and has a more beautiful appearance.

[0039] In an alternative embodiment, the intersection point of the base circle section and the second leading edge portion is the sixth point. The tangent line of the second leading edge portion at the sixth point is the second tangent line. The intersection point of the second leading edge portion and the outer diameter circle of the hub is the seventh point. The line connecting the seventh point and the center of the circle is the eleventh connecting line. The angle between the eleventh connecting line and the second tangent line is A4. A4 is the bending angle of the second leading edge portion, and -55° ≤ A4 ≤ 0°.

[0040] Beneficial effects: In this embodiment, the bending angle of the second leading edge portion is between -55° and 0°, which conforms to the shape of a petal and has a more beautiful appearance.

[0041] 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 = 0.8, A4 is 33°.

[0042] Advantageous effects: In this embodiment, the shape of the second leading edge portion conforms to the shape of a petal, making the appearance more beautiful.

[0043] In a second aspect, the present invention further provides an air conditioning device, comprising:

[0044] The axial flow fan blade provided in the first aspect of the present invention.

[0045] The air conditioning device according to the second aspect of the present invention includes or uses the air conditioning device according to the first aspect of the present invention, and thus can achieve its advantageous effects, that is, it can overcome the defects in the related art that the energy loss and noise of the fan blade are relatively large during use, and it is easy to cause aesthetic fatigue of users. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0047] Figure 1 The front view of an axial flow fan blade according to an embodiment of the present invention;

[0048] Figure 2 The structural schematic diagram of an axial flow fan blade according to an embodiment of the present invention Figure 1 ;

[0049] Figure 3 The structural schematic diagram of an axial flow fan blade according to an embodiment of the present invention Figure 2 ;

[0050] Figure 4 The structural schematic diagram of an axial flow fan blade according to an embodiment of the present invention Figure 3 ;

[0051] Figure 5 The partial schematic diagram of an axial flow fan blade according to an embodiment of the present invention Figure 1 ;

[0052] Figure 6 The partial schematic diagram of an axial flow fan blade according to an embodiment of the present invention Figure 2 ;

[0053] Figure 7Partial schematic diagram of an axial flow fan blade according to an embodiment of the present invention Figure 3 ;

[0054] Figure 8 Cross-sectional view of the first blade and the second blade of an axial flow fan blade according to an embodiment of the present invention on the base circle section;

[0055] Figure 9 Partial structural schematic diagram of an axial flow fan blade according to an embodiment of the present invention Figure 1 ;

[0056] Figure 10 Partial structural schematic diagram of an axial flow fan blade according to an embodiment of the present invention Figure 2 ;

[0057] Figure 11 is Figure 10 Enlarged view of location A in

[0058] Figure 12 Schematic diagram of simulating the fan blade according to an embodiment of the present invention and a traditional fan blade.

[0059] Explanation of reference numerals:

[0060] 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;

[0061] 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;

[0062] 3. Hub; 301. Inlet end; 302. Outlet end; 4. Depression; 5. Connection structure;

[0063] O. Center of circle; B1. Midpoint of the chord of the first blade root; B2. Midpoint of the chord of the second blade root; C1. Midpoint of the chord of the first blade; C2. Midpoint of the chord of the second blade;

[0064] I. First point; J. Second point; Y. Third point; E. Fourth point; H. Fifth point; G. Sixth point; F. Seventh point; M1. First inflection point; M2. Second inflection point;

[0065] L9. First connection line; L 11 ., Second connection line; L 12 ., Third connection line; L 10 ., Fourth connection line; L 13, the fifth connection line; L2, the sixth connection line; L1, the seventh connection line; L3, the eighth connection line; L6, the ninth connection line; L5, the tenth connection line; L7, the eleventh connection line;

[0066] L4, the first tangent line; L8, the second tangent line;

[0067] b1, the first chord line; b2, the second chord line. Detailed implementation manners

[0068] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some but not all of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0069] Most of the fans in the related art adopt traditional axial-flow blades, and the blades are usually designed as straight blades or spiral blades. The traditional blade shapes are limited and there has been no breakthrough in appearance for many years, which is likely to cause aesthetic fatigue among consumers and reduce the sales power of products. Secondly, although the traditional blade aerodynamic design can meet the basic air supply requirements, there are deficiencies in aspects such as air flow efficiency and noise control. The traditional blade design has a greater impact on the air flow path, and eddy currents are likely to be generated at the blade tips and trailing edges of the blades, resulting in energy loss and increased noise. In addition, most traditional blades are single-blade designs, and during their molding, they are easily deformed and collapsed at the blade tip positions with weak structures due to the influence of materials and injection molding processes, changing the aerodynamic performance of the blades themselves, and there are often injection molding performance errors during the product development process, which bring difficulties to the scheme confirmation and motor matching.

[0070] The double-blade structure in the related art includes a plurality of blades provided on the circumferential side surface of the hub. An air passing hole is formed on each blade or between each blade and the hub. The blade includes at least two rectifying segments on the periphery of the air passing hole. The suction surface of one rectifying segment is connected to the pressure surface of the other rectifying segment. Therefore, in the direction from the leading edge of the flow guiding segment to the trailing edge of the flow guiding segment, the bending directions of the two connected rectifying units are opposite, and the flow guiding effect is poor. In addition, the blade tip width of this kind of blade is relatively narrow, and eddy currents are likely to be generated at the blade tips and trailing edges of the blades, resulting in energy loss and increased noise.

[0071] The following will be combined with Figures 1 to 12 , to describe the embodiments of the present invention.

[0072] According to an embodiment of the present invention, on the one hand, an axial-flow blade is provided, which includes a hub 3 and a plurality of blade units.

[0073] Among them, multiple blade units are connected to the hub 3 and are circumferentially spaced along the hub 3. Each blade unit includes a first blade 1 and a second blade 2. The first blade 1 includes a first blade root 101, a first blade tip 102, a first leading edge 103, and a first trailing edge 104. The second blade 2 includes a second blade root 201, a second blade tip 202, a second leading edge 203, and a second trailing edge 204. The second trailing edge 204 is connected to the first leading edge 103. The first blade tip 102 and the second blade tip 202 are arched and arched away from the hub 3.

[0074] The blade unit of the axial-flow fan blade in the embodiment of the present invention is composed of a first blade 1 and a second blade 2. By means of double-blade fitting, the blade tips of each blade unit form an "M"-shaped arched shape, making the shape of the blade closer to the petal shape, enhancing the aesthetics of the axial-flow fan blade, breaking the user's aesthetic fatigue of the axial-flow fan blade, and increasing the visual attraction of the product.

[0075] On this basis, since the blade unit of the axial-flow fan blade of the present application is formed by fitting the first blade 1 and the second blade 2, the tip width of the blade unit can be extended, thereby delaying the formation length of the air flow in the tip region, reducing the scale and magnitude when the air flow detaches from the tip region, and further reducing the discrete noise generated when the axial-flow fan blade rotates.

[0076] Also, since the blade unit of the axial-flow fan blade of the present application forms an "M"-shaped arched shape at the blade tips of each blade unit, a recess 4 is formed at the connection between the first blade tip 102 and the second blade tip 202. The recess 4 can offset the air flow to a certain extent, further reducing the scale and magnitude when the air flow detaches from the tip region, further reducing the vortex detachment at the blade tips and trailing edges of the blade, and thus reducing the vortex noise of the blade.

[0077] Therefore, the axial-flow fan blade of the present application can overcome the defects in the related art that the fan blade has large energy loss and noise during use and is prone to causing user aesthetic fatigue.

[0078] In one embodiment, the first blade tip 102 and the second blade tip 202 are connected at the middle position of the blade unit.

[0079] By setting it in this way, the blade tips of each blade unit form an "M"-shaped arched shape, making the shape of the blade closer to the petal shape, and enhancing the aesthetics of the axial-flow fan blade.

[0080] In one embodiment, the first blade tip 102 and the second blade tip 202 are provided with a wedge-shaped connection structure 5 that transitions from the first suction surface 105 to the second suction surface 205.

[0081] In this embodiment, the first suction surface 105 and the second suction surface 205 are connected by a wedge-shaped connection structure 5, which can effectively prevent the tip collapse during blade forming and enhance the firmness of blade forming.

[0082] Specifically, in one embodiment, the curvature of the wedge-shaped connection structure 5 is the same as that of the second blade top 202, which can reduce the influence of the wedge-shaped connection structure 5 on the air flow.

[0083] In one embodiment, the maximum outer edge radius of the blade unit is R;

[0084] In one embodiment, as Figure 6 shown, the intersection point between the first blade top 102 and the first trailing edge 104 is the first point I, the distance between the first point I and the center O of the hub 3 is R', and 0.95 > R' / R > 0.75.

[0085] The intersection point between the second blade top 202 and the second leading edge 203 is the second point J, the distance between the second point J and the center O of the hub 3 is R', and 0.95 > R' / R > 0.75.

[0086] Taking the center O of the blade hub 3 as the base point, different axial cylindrical base circle sections with a radius of r are made. When the part of the blade intercepted by the base circle section is the blade top of the wind blade, the axial projection curve of the base circle section with a radius of R' is the blade top demarcation line of the wind blade. When the blade top is in the above area, it can ensure that the shape of the axial flow wind blade is closer to the petal shape and does not affect the overall aerodynamic performance of the blade unit.

[0087] In a preferred embodiment, R' = 0.85. It can ensure that the shape of the axial flow wind blade is closer to the petal shape and does not affect the overall aerodynamic performance of the blade unit.

[0088] In one embodiment, the intersection point between the first blade top 102 and the first trailing edge is the first point I, the intersection point between the first blade top 102 and the second blade top 202 is the third point Y. Taking the center O of the hub 3 as the base point, an axial cylindrical base circle section with a radius of r is made. The connection line between the center O and the first point I is the first connection line L9, and the connection line between the center O and the third point Y is the second connection line L 11 , the included angle between the first connection line L9 and the second connection line L 11 is θ1; the blade top of the first blade 1 arches away from the hub 3 to form a first inflection point M1, and the connection line between the first inflection point M1 and the center O of the hub 3 is the third connection line L 12 , the third connection line L 12 and the first connection line L9 is θM1, and 0.3 ≤ θM1 / θ1 ≤ 0.7.

[0089] θ1 is the tip distribution angle of the first blade 1, θM1 is the crown part distribution angle, and θM1 satisfies 0.3 ≤ θM1 / θ1 ≤ 0.7. When the curve of the first blade tip 102 is distributed between 0 and θM1, the blade tip curve bends upward in the clockwise direction of the wind turbine rotation. When the curve of the first blade tip 102 is distributed between θM1 and θ1, the blade tip curve of the first blade 1 bends downward in the clockwise direction of the wind turbine rotation. When 0.3 ≤ θM1 / θ1 ≤ 0.7, a petal arch shape similar to the "M" shape can be formed at the blade tip position of the blade unit.

[0090] The intersection point between the second blade tip 202 and the second leading edge 203 is the second point J. The intersection point between the first blade tip 102 and the second blade tip 202 is the third point Y. Taking the center O of the hub 3 as the base point, an axial cylindrical base circle section with a radius of r is made. The connection line between the center O and the second point J is the fourth connection line L 10 , and the connection line between the center O and the third point Y is the second connection line L 11 , the blade tip of the second blade 2 arches away from the hub 3 and forms a second inflection point M2. The connection line between the center O and the second inflection point M2 is the fifth connection line L 13 , the fifth connection line L 13 and the fourth connection line L 10 The included angle between them is θM2, and 0.3 ≤ θM2 / θ2 ≤ 0.7.

[0091] Taking the fourth connection line L10 as the starting line for the second blade tip 202 of the second blade 2, θM2 is the arch distribution angle of the second blade tip 202. When the blade tip curve of the second blade tip 202 is distributed between 0 and θM2, the blade tip curve bends upward in the counterclockwise direction of the wind turbine rotation. When it is distributed between θM2 and θ2, the blade tip curve bends downward in the counterclockwise direction of the wind turbine rotation. When 0.3 ≤ θM2 / θ2 ≤ 0.7, a petal arch shape similar to the "M" shape can be formed at the blade tip position of the blade unit.

[0092] In this embodiment, each blade unit is composed of the first blade 1 and the second blade 2. Adopting the double - blade fitting method, the structure of the blade unit is novel and beautiful in appearance. The blade unit is closer to the petal shape, and since each blade unit is composed of the first blade 1 and the second blade 2, the aerodynamic performance of the fan can be improved.

[0093] Specifically, in one embodiment, the number of blade units is n, n ≥ 3. In this embodiment, n = 5 is selected to make the shape of the blade unit closer to the petal shape.

[0094] It should be noted that the first blade 1 and the second blade 2 are arranged in the direction consistent with the wind blade rotation direction. The first blade 1 further includes a first suction surface 105 and a first pressure surface 106. The second blade 2 includes a second suction surface 205 and a second pressure surface 206. The axial flow wind blade rotates in the clockwise direction, and each blade unit is the second blade 2 and the first blade 1 in sequence in the clockwise direction.

[0095] 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.

[0096] In one embodiment, the axial flow wind blade includes a hub 3, the blade units are 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.

[0097] In this embodiment, d / D refers to the hub ratio. The hub ratio is an important design parameter of the axial flow fan. If the hub ratio is too large, the efficiency of the fan will be reduced, and the aerodynamic performance of the whole machine will be decreased. On the contrary, if the hub ratio of the axial flow fan is too small, airflow separation will occur at the root of the fan blade, resulting in performance loss of the wind blade. Therefore, in this embodiment, by making the hub 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.

[0098] Specifically, in one embodiment, the hub ratio is 0.2.

[0099] Specifically, in one embodiment, the hub ratio is 0.24.

[0100] Specifically, in one embodiment, the hub ratio is 0.35.

[0101] In one embodiment, from the first trailing edge portion 104 to the first leading edge portion 103, the first blade top 102 is bent and swept in the direction consistent with the wind blade rotation direction and the net bend angle gradually increases.

[0102] In this embodiment, from the first trailing edge portion 104 to the first leading edge portion 103, the first blade top 102 is bent and swept in the direction consistent with the wind blade rotation direction and the net bend angle gradually increases, which can increase the drainage trend of the first blade 1, reduce the double-blade turbulence influence, and facilitate the fitting of the first blade 1 and the second blade 2.

[0103] In one embodiment, the maximum outer edge radius of the blade unit is R. Taking the center O of the hub 3 as the base point, an axial cylindrical base circle section with a radius of r is made. The connection line between the center O and the chord midpoint B1 of the first blade root is the sixth connection line L2, and the connection line between the center O and the chord midpoint C1 of the first blade at the base circle section is the seventh connection line L1. The included angle between the sixth connection line L2 and the seventh connection line L1 is A1, and A1 is the net bending angle of the first blade 1. From the first blade root 101 to the first blade tip 102, A1 gradually increases.

[0104] In this embodiment, from the first blade root 101 to the first blade tip 102, the net bending angle of the first blade 1 gradually increases, which can increase the drainage trend of the first blade 1 and reduce the influence of double - blade flow interference.

[0105] It should be noted that from the first blade root 101 to the first blade tip 102, as A1 gradually increases, in fact, from the first blade root 101 to the first blade tip 102, the seventh connection line L1 gradually moves away from the sixth connection line L2 in the clockwise direction. Therefore, as a whole, from the first trailing edge 104 to the first leading edge 103, the first blade tip 102 is bent and swept in the direction consistent with the rotation direction of the wind blade and the net bending angle gradually increases.

[0106] In one embodiment, 0°≤A1≤15°.

[0107] In one 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 = 0.8, A1 is 9°.

[0108] In one embodiment, from the first blade root 101 to the first blade tip 102, the first trailing edge 104 is bent and swept in the direction consistent with the rotation direction of the wind blade and the bending angle of the first trailing edge 104 gradually increases.

[0109] In this embodiment, since the shape of the blade trailing edge affects the working area on the blade surface and the distribution of the pressure gradient on the blade surface, when the airflow on the blade surface flows through the blade trailing edge, due to the shedding of the wake vortex, local pressure pulsating force is easily generated, forming vortex noise. By making the first trailing edge 104 bent and swept in the direction consistent with the rotation direction of the wind blade and the bending angle of the first trailing edge 104 gradually increasing, the vortex shedding of the first trailing edge 104 can be reduced.

[0110] In one embodiment, the intersection point of the first trailing edge 104 and the outer diameter circle of the hub 3 is the fifth point H, the connection line between the fifth point H and the center O is the eighth connection line L3, the intersection point of the base circle section and the first trailing edge 104 is the fourth point E, and the tangent line of the first trailing edge 104 at the fourth point E is the first tangent line L4. The included angle between the eighth connection line L3 and the first tangent line L4 is A2, and A2 is the bending angle of the first trailing edge 104, 0°≤A2≤55°.

[0111] In this embodiment, by making 0° ≤ A2 ≤ 55°, the vortex shedding at the first trailing edge portion 104 can be reduced, and the first blade 1 can satisfy the petal appearance shape.

[0112] In one 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 = 0.8, A2 is 41°.

[0113] In this embodiment, the vortex shedding at the first trailing edge portion 104 can be reduced, and the first blade 1 can satisfy the petal appearance shape.

[0114] In one embodiment, from the second trailing edge portion 204 to the second leading edge portion 203, the second blade top 202 is bent and swept in the reverse direction of the wind blade rotation, and the net bending angle gradually increases.

[0115] In this embodiment, from the second trailing edge portion 204 to the second leading edge portion 203, the second blade top 202 is bent and swept in the direction opposite to the wind blade rotation and the net bending angle gradually increases, which can increase the drainage trend of the second blade 2, reduce the double - blade flow interference effect, and facilitate the fitting of the second blade 2 and the second blade 2.

[0116] In one embodiment, the line connecting the center O and the chord mid - point B2 of the second blade root is the ninth connecting line L6, the line connecting the chord mid - point C2 of the second blade at the base circle section and the center O is the tenth connecting line L5, the included angle between the ninth connecting line L6 and the tenth connecting line L5 is A3, A3 is the net bending angle of the second blade 2, and from the second blade root 201 to the second blade top 202, A3 gradually increases.

[0117] In this embodiment, from the second blade root 201 to the second blade top 202, the net bending angle of the second blade 2 gradually increases, which can increase the drainage trend of the second blade 2 and reduce the double - blade flow interference effect.

[0118] It should be noted that from the second blade root 201 to the second blade top 202, as A3 gradually increases, actually from the second blade root 201 to the second blade top 202, the tenth connecting line L5 gradually moves away from the seventh connecting line L1 in the counter - clockwise direction. Therefore, overall, from the second trailing edge portion 204 to the second leading edge portion 203, the second blade top 202 is bent and swept in the reverse direction of the wind blade rotation and the net bending angle gradually increases.

[0119] In one embodiment, - 15° ≤ A3 ≤ 0°.

[0120] It should be noted that A3 being negative means that the tenth connecting line L5 is on the counter - clockwise side of the ninth connecting line L6. Combining Figure 7 , the tenth connecting line L5 is on the left side of the ninth connecting line L6.

[0121] 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 = 0.8, A3 is -7°.

[0122] In one embodiment, from the second blade root 201 to the second blade tip 202, the second leading edge 203 is bent and swept in the reverse direction of the blade rotation direction, and the bending and sweeping angle of the second leading edge 203 gradually increases.

[0123] In this embodiment, the second leading edge 203 is bent and swept in the reverse direction of the blade rotation direction, and the bending and sweeping angle of the second leading edge 203 gradually increases, which conforms to the shape of a petal and has a more beautiful appearance.

[0124] In one embodiment, the intersection point of the base circle section and the second leading edge 203 is the sixth point G. The tangent line of the second leading edge 203 at the sixth point G is the second tangent line L8. The intersection point of the second leading edge 203 and the outer diameter circle of the hub 3 is the seventh point F. The connection line between the seventh point F and the center O is the eleventh connection line L7. The included angle between the eleventh connection line L7 and the second tangent line L8 is A4, and A4 is the bending and sweeping angle of the second leading edge 203, where -55° ≤ A4 ≤ 0°.

[0125] In this embodiment, the bending and sweeping angle of the second leading edge 203 is between -55° and 0°, which conforms to the shape of a petal and has a more beautiful appearance.

[0126] It should be noted that a negative A4 value represents that the second tangent line L8 is on the counterclockwise side of the eleventh connection line L7. Combining Figure 7 , the second tangent line L8 is on the left side of the eleventh connection line L7.

[0127] 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 = 0.8, A4 is -33°.

[0128] In this embodiment, the shape of the second leading edge 203 conforms to the shape of a petal and has a more beautiful appearance.

[0129] In one embodiment, from the first blade root 101 to the first blade tip 102, the first leading edge 103 is bent and swept in the same direction as the blade rotation direction, and the bending and sweeping angle of the first leading edge 103 gradually increases.

[0130] In this embodiment, since the first blade 1 is located behind the second blade 2 when the axial-flow fan blade rotates clockwise, the airflow on its blade surface will be more or less affected by the second trailing edge portion 204, thereby affecting the work efficiency of the first blade 1. Therefore, by bending the first leading edge portion 103 in the direction consistent with the rotation direction of the fan blade and gradually increasing the bending angle of the first leading edge portion 103, the drainage trend of the first blade 1 can be increased and the double-blade turbulence effect can be reduced.

[0131] In this embodiment, by making the bending angle of the first leading edge portion 103 between 0° and 10°, it is convenient for the fitting of the first blade 1 and the second blade 2.

[0132] 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°; when r / R = 0.95, A5 is 9°.

[0133] 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 bent 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 second cross-section 207 is bent in the same direction as the rotation direction of the fan blade.

[0134] In this embodiment, by making the first cross-section 107 bent 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 making the second cross-section 207 bent 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 drainage trend can be increased and the airflow can flow more smoothly.

[0135] In one embodiment, on the first cross-section 107, the connection line between 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 face of the air inlet end 301 of the hub 3 is Q1. On the second cross-section 207, the connection line between 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 face of the air inlet end 301 of the hub 3 is Q2;

[0136] When r / R = 0.4, 35° ≤ Q1 ≤ 45°, 35° ≤ Q2 ≤ 45°;

[0137] When r / R = 0.55, 30° ≤ Q1 ≤ 35°, 30° ≤ Q2 ≤ 40°;

[0138] When r / R = 0.7, 25° ≤ Q1 ≤ 30°, 25° ≤ Q2 ≤ 35°;

[0139] When r / R = 0.85, 20° ≤ Q1 ≤ 30°, 20° ≤ Q2 ≤ 30°;

[0140] When r / R = 0.98, 15° ≤ Q1 ≤ 25°, 0° ≤ Q2 ≤ 10°.

[0141] Specifically, in one embodiment, when r / R = 0.4, Q1 = 36.2°, Q2 ≤ 36.2°;

[0142] When r / R = 0.55, Q1 = 30.6°, Q2 ≤ 33.5°;

[0143] When r / R = 0.7, Q1 = 26.8°, Q2 ≤ 29.9°;

[0144] When r / R = 0.85, Q1 = 23.7°, Q2 ≤ 23.3°;

[0145] When r / R = 0.98, Q1 = 20.4°, Q2 ≤ 7°.

[0146] In one embodiment, the first leading edge portion 103 is recessed toward the side where the air inlet end 301 of the hub 3 is located, the second trailing edge portion 204 is arched toward the side where the air outlet end 302 of the hub 3 is located, and the first blade top 102 is connected to the second blade top 202.

[0147] In this embodiment, by making the first leading edge portion 103 recessed toward the side where the air inlet end 301 of the hub 3 is located, the second trailing edge portion 204 arched toward the side where the air outlet end 302 of the hub 3 is located, and the first blade top 102 connected to the second blade top 202, through such a setting, as Figure 8 shown, in the direction from the leading edge to the trailing edge, the bending directions of the first blade 1 and the second blade 2 of the present application are the same, which can enable a sufficient flow-through area between the first blade 1 and the second blade 2, make the airflow flow more smoothly between the double blades, improve the aerodynamic performance and the air guiding effect of the blades, and at the same time facilitate the transition fitting of the petal-shaped styling at the tops of the double blades.

[0148] In one embodiment, the first trailing edge portion 104, the first blade top 102, the second leading edge portion 203, and the second blade top 202 are provided with rounded corners. Along the rotation direction of the wind blade, from the first trailing edge portion 104 to the first blade top 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 top 102 to the first leading edge portion 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 portion 204 to the second blade top 202, the second blade 2 bends toward the side where the air inlet end 301 of the hub 3 is located, and from the second blade top 202 to the second leading edge portion 203, the second blade 2 bends toward the side where the air outlet end 302 of the hub 3 is located.

[0149] In this embodiment, the shape of the blade unit is more in line with the petal styling, and the appearance is more beautiful.

[0150] In one embodiment, a recess 4 is formed at the connection between the top 102 of the first blade and the top 202 of the second blade.

[0151] In this embodiment, a recess 4 is formed at the connection between the top 102 of the first blade and the top 202 of the second blade, and the shape of the blade unit is more in line with the shape of a petal, making the appearance more beautiful.

[0152] Combined Figure 12 , the axial-flow fan blade provided in this embodiment can effectively reduce the vortex detachment at the top and trailing edge of the blade compared with the traditional fan blade, thereby reducing the vortex noise of the blade. At the same time, it can effectively improve the aerodynamic loss caused by the airflow separation on the blade surface and improve the air volume performance of the fan blade. As shown in the following table, compared with the traditional conventional fan blade, the noise and air volume performance of the fan blade solution of the patent embodiment are significantly improved.

[0153] Wind blade solution Air volume (m3 / min) Noise (dB) Traditional wind blade 41 61 Wind blade of this embodiment 47 59.3

[0154] According to an embodiment of the present invention, on the other hand, an air conditioning device is also provided, including the axial-flow fan blade provided in the above embodiment.

[0155] The air conditioning device of the second aspect of the present invention includes or uses the air conditioning device of the first aspect of the present invention, and thus can achieve its beneficial effects, that is, it can overcome the defects in the related art that the energy loss and noise of the fan blade are large during use, and it is easy to cause aesthetic fatigue of users.

[0156] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope claimed by the present invention.

Claims

1. An axial flow fan blade, characterized in that: include: Wheel hub (3); A plurality of blade units connected to the hub (3) and spaced apart along the circumference of the hub (3), each blade unit comprising a first blade (1) and a second blade (2); A first blade (1), comprising a first blade root portion (101), a first blade top portion (102), a first leading edge portion (103) and a first trailing edge portion (104); The second blade (2) comprises a second blade root portion (201), a second blade top portion (202), a second leading edge portion (203) and a second trailing edge portion (204); the second trailing edge portion (204) is connected to the first leading edge portion (103); the first blade top portion (102) and the second blade top portion (202) are arched and arched in a direction away from the hub (3).

2. The axial flow fan blade according to claim 1, characterized in that: The first blade top (102) and the second blade top (202) are connected at a middle position of the blade unit.

3. The axial flow fan blade according to claim 1, characterized in that: The maximum outer edge radius of the blade unit is R; The intersection point between the first blade top (102) and the first trailing edge (104) is a first point (I), the distance between the first point (I) and the center (O) of the hub (3) is R', 0.95>R' / R>0.75; and / or, The intersection point between the second blade top (202) and the second leading edge (203) is a second point (J), and the distance between the second point (J) and the center (O) of the hub (3) is R', and 0.95>R' / R>0.

75.

4. The axial flow fan blade according to claim 2, characterized in that: The intersection point between the first blade top (102) and the first trailing edge is the first point (I), the intersection point between the first blade top (102) and the second blade top (202) is the third point (Y), the center (O) of the hub (3) is used as the base point, an axial cylindrical base circle section with a radius of r is made, the line connecting the center (O) and the first point (I) is the first connecting line (L9), the line connecting the center (O) and the third point (Y) is the second connecting line (L 11 ), the first connection line (L9) and the second connection line (L 11 ) is θ1; the top of the first blade (1) is arched in a direction away from the hub (3) to form a first inflection point (M1); a line connecting the first inflection point (M1) and the center (O) of the hub (3) is a third connecting line (L 12 ), the third line (L 12 ) and the first connecting line (L9) is θM1, 0.3≤θM1 / θ1≤0.

7.

5. The axial flow fan blade according to claim 2, characterized in that: The intersection point between the second blade top (202) and the second leading edge (203) is the second point (J), the intersection point between the first blade top (102) and the second blade top (202) is the third point (Y), and an axial cylindrical base circle section with a radius of r is made with the center (O) of the hub (3) as the base point. The line between the center (O) and the second point (J) is the fourth line (L 10 ), the line connecting the center (O) and the third point (Y) is the second line (L 11 ), the top of the second blade (2) arches in a direction away from the hub (3) and forms a second inflection point (M2), and the line between the center (O) and the second inflection point (M2) is the fifth line (L 13 ), the fifth line (L 13 ) and the fourth line (L 10 ) is θM2, 0.3≤θM2 / θ2≤0.

7.

6. The axial flow fan blade according to any one of claims 1 to 5, characterized in that: The outer diameter of the blade unit is D, the diameter of the hub (3) is d, and 0.2≤d / D≤0.

35.

7. The axial flow fan blade according to claim 6, characterized in that: From the first trailing edge portion (104) to the first leading edge portion (103), the first blade top portion (102) bends in a direction consistent with the rotation direction of the axial flow blade and the net bending angle gradually increases.

8. The axial flow fan blade according to claim 6, characterized in that: 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 (O) of the hub (3) as a base point. The line connecting the center (O) and the chord midpoint (B1) of the first blade root is the sixth line (L2), and the line connecting the chord midpoint (C1) of the first blade at the base circle section and the center (O) is the seventh line (L1). The angle between the sixth line (L2) and the seventh line (L1) is A1, and A1 is the net bending angle of the first blade (1). From the first blade root (101) to the first blade top (102), A1 gradually increases.

9. The axial flow fan blade according to claim 6, characterized in that: 0°≤A1≤15°。 10. The axial flow fan blade according to claim 6, characterized in that: 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=0.8, A1 is 9°.

11. The axial flow fan blade according to claim 8, characterized in that: From the first blade root (101) to the first blade top (102), the first trailing edge (104) is bent in a direction consistent with the rotation direction of the axial flow fan blade, and the bending angle of the first trailing edge (104) gradually increases.

12. The axial flow fan blade according to claim 11, characterized in that: The intersection of the first trailing edge portion (104) and the outer diameter circle of the hub (3) is a fifth point (H), the line connecting the fifth point (H) and the center (O) is an eighth line (L3), an axial cylindrical base circular section with a radius of r is made with the center (O) of the hub (3) as a base point, the intersection of the base circular section and the first trailing edge portion (104) is a fourth point (E), the tangent of the first trailing edge portion (104) at the fourth point (E) is a first tangent (L4), the angle between the eighth line (L3) and the first tangent (L4) is A2, A2 is a bending angle of the first trailing edge portion (104), 0°≤A2≤55°.

13. The axial flow fan blade according to claim 12, characterized in that: 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=0.8, A2 is 41°.

14. The axial flow fan blade according to any one of claims 1 to 5, characterized in that: From the second trailing edge portion (204) to the second leading edge portion (203), the second blade top portion (202) is bent in the opposite direction to the rotation direction of the blade, and the net bending angle gradually increases.

15. The axial flow fan blade according to claim 14, characterized in that: Taking the center (O) of the hub (3) as the base point, an axial cylindrical base circular section with a radius of r is made, the line connecting the center (O) and the chord midpoint (B2) of the second blade root is the ninth connecting line (L6), the line connecting the chord midpoint (C2) of the second blade at the base circular section and the center (O) is the tenth connecting line (L5), the angle between the ninth connecting line (L6) and the tenth connecting line (L5) is A3, A3 is the net bending angle of the second blade (2), and A3 gradually increases from the second blade root (201) to the second blade top (202).

16. The axial flow fan blade according to claim 15, characterized in that: -15°≤A3≤0°。 17. The axial flow fan blade according to claim 15, characterized in that: 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=0.8, A3 is -7°.

18. The axial flow fan blade according to any one of claims 1 to 5, characterized in that: From the second blade root (201) to the second blade top (202), the second leading edge (203) is bent in the opposite direction to the rotation direction of the wind blade, and the bending angle of the second leading edge (203) gradually increases.

19. The axial flow fan blade according to claim 18, characterized in that: Taking the center (O) of the wheel hub (3) as the base point, make an axial cylindrical base circular section with a radius of r, the intersection of the base circular section and the second leading edge portion (203) is the sixth point (G), the tangent of the second leading edge portion (203) at the sixth point (G) is the second tangent (L8), the intersection of the second leading edge portion (203) and the outer diameter circle of the wheel hub (3) is the seventh point (F), the line connecting the seventh point (F) and the center (O) is the eleventh line (L7), the angle between the eleventh line (L7) and the second tangent (L8) is A4, A4 is the sweep angle of the second leading edge portion (203), -55°≤A4≤0°.

20. The axial flow fan blade according to claim 19, characterized in that: 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=0.8, A4 is 33°.

21. An air conditioning device, characterized in that: include: The axial flow fan blade according to any one of claims 1 to 20.

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