Axial fans and air conditioners

Abstract

The present invention relates to an axial flow fan and an air conditioner. The axial flow fan comprises: a blade, wherein the blade comprises a leading edge and a trailing edge, and the contour line of the trailing edge is a Bezier curve. The trailing edge presents a spatial Bezier curve structure, which is an irregular curve structure; compared with regular curve structures such as a straight line structure or an arc structure, it can optimize blade performance, reduce the shedding of blade wake vortices, and reduce noise.

Description

Technical Field

[0001] The present invention relates to the field of axial flow fans, and in particular to an axial flow fan and an air conditioner. Background Art

[0002] An axial flow fan is generally used as an air supply component in an air conditioner outdoor unit. The axial flow fan includes a hub and a number of blades arranged on the hub. The structure of the blades directly affects the overall performance of the axial flow fan and the air conditioner. In the related art, when the blades rotate with the hub, there is a strong trembling vibration phenomenon, which in turn causes the vibration of the entire axial flow fan and generates a lot of noise. Summary of the invention

[0003] Some embodiments of the present invention provide an axial flow fan and an air conditioner to alleviate the problem of high noise.

[0004] Some embodiments of the present invention provide an axial flow fan, comprising: a blade, wherein the blade comprises a leading edge and a trailing edge, and a contour line of the trailing edge is a Bezier curve.

[0005] In some embodiments, the axial flow fan further comprises a hub, and the blades are disposed on the hub;

[0006] The blade and the hub are projected on a first plane perpendicular to the axis of the hub to form a first projection; in the first projection, the projection corresponding to the trailing edge is a Bezier curve.

[0007] In some embodiments, the portion where the blade is connected to the hub is the blade root, and the portion of the blade opposite to the blade root is the blade tip;

[0008] In the first projection, the intersection of the leading edge and the hub is a first intersection, the intersection of the axis of the hub and the first plane is a second intersection, and the line connecting the first intersection and the second intersection is a first connection line;

[0009] A line connecting the second intersection point and a point selected on the trailing edge is a second line, and an angle greater than zero is formed between the first line and the second line;

[0010] The closer a point selected on the trailing edge is to the blade tip, the smaller the angle between the first connecting line and the second connecting line.

[0011] In some embodiments, in the first projection, the intersection of the trailing edge and the hub is a third intersection, a line between the third intersection and the second intersection is a third line, and an angle between the third line and the first line ranges from 90° to 120°.

[0012] In some embodiments, the intersection of the trailing edge and the blade top is the fourth intersection, the line between the fourth intersection and the second intersection is the fourth line, and the angle between the fourth line and the first line is in the range of 30° to 60°.

[0013] In some embodiments, the blade is projected onto a second plane to form a second projection; in the second projection, the projection corresponding to the trailing edge is a Bezier curve;

[0014] The second plane is perpendicular to the first plane; in the first projection, the intersection of the leading edge and the hub is the first intersection, the intersection of the axis of the hub and the first plane is the second intersection, and the line connecting the first intersection and the second intersection is the first line; the first line is located in the second plane.

[0015] In some embodiments, in the second projection, the intersection point of the trailing edge and the blade root is a fifth intersection point, the intersection point of the trailing edge and the blade top is a sixth intersection point, and a line passing through the fifth intersection point and perpendicular to the blade root is a first line;

[0016] In the second projection, the trailing edge has a first point, the first point is far from the first line relative to the fifth intersection point, and the first point is close to the first line relative to the sixth intersection point.

[0017] In some embodiments, in the second projection, the distance between the first point and the blade root is L1, and the value range of L1 is 0.2R to 0.28R, where R is the radius of the axial flow fan.

[0018] In some embodiments, in the second projection, the trailing edge has a second point, the second point is farther from the blade root than the first point, and the second point is farthest from the first line compared to other points on the trailing edge.

[0019] In some embodiments, in the second projection, the line passing through the first point and parallel to the blade root is the second line, the line passing through the second point and parallel to the blade root is the third line, the distance between the second line and the third line is L2, the value range of L2 is 0.28R~0.43R, and R is the radius of the axial flow fan.

[0020] In some embodiments, in the second projection, a line connecting the fifth intersection point and the sixth intersection point is a fifth line, an angle between the first line and the fifth line is α1, and a value range of α1 is 0° to 20°.

[0021] In some embodiments, in the second projection, the trailing edge has a second point, the second point is farther from the blade root than the first point, and the second point is farthest from the first line compared to other points on the trailing edge;

[0022] The line connecting the fifth intersection point and the second point is the sixth line, the angle between the first line and the sixth line is α2, the value range of α2 is 0° to 20°, and α2 is greater than α1.

[0023] In some embodiments, 1°<α2-α1<10°.

[0024] In some embodiments, the leading edge is provided with a first rib, and the first rib extends from the blade root to the blade tip.

[0025] In some embodiments, the extension length of the first rib is 0.85R to 0.9R, where R is the radius of the axial flow fan.

[0026] In some embodiments, the first rib is disposed on the suction surface of the blade.

[0027] In some embodiments, the end of the first rib close to the blade top is the top, the distance of the top from the suction surface to the pressure surface of the blade is the height H, the height H gradually decreases from the leading edge to the trailing edge, the line between the highest point of the top closest to the leading edge and the lowest point closest to the trailing edge is the seventh line, the line between the point of the top closest to the leading edge and the point closest to the trailing edge is the eighth line, the angle between the seventh line and the eighth line is β, and the angle value range of β is 5° to 15°.

[0028] In some embodiments, the height H of the top closest to the front edge ranges from 2 mm to 8 mm, the length of the eighth connecting line is L3, and the value range of L3 is 10 mm to 20 mm.

[0029] In some embodiments, the leading edge is provided with a second rib, and the second rib connects the hub and the first rib.

[0030] In some embodiments, an extension length of the second rib from the hub to the blade tip is 0.2R to 0.3R, where R is the radius of the axial flow fan.

[0031] In some embodiments, the second rib runs through the suction surface and the pressure surface of the blade.

[0032] In some embodiments, the suction surface of the blade is provided with a groove, and the shape of the groove matches the shape of the suction surface of the blade.

[0033] In some embodiments, a third rib and a fourth rib are disposed in the groove, and both the third rib and the fourth rib extend along a direction from the leading edge to the trailing edge.

[0034] In some embodiments, the third rib is closer to the blade root than the fourth rib, the distance between the third rib and the blade root is 0.2R to 0.3R, the distance between the fourth rib and the blade root is 0.45R to 0.55R, and R is the radius of the axial flow fan.

[0035] Some embodiments of the present invention provide an air conditioner comprising the above-mentioned axial flow fan.

[0036] Based on the above technical solution, the present invention has at least the following beneficial effects:

[0037] In some embodiments, the contour line of the trailing edge of the blade adopts a Bezier curve, and the trailing edge presents a spatial Bezier curve structure, which is an irregular curve structure; compared with regular curve structures such as straight line structures or arc structures, it can optimize blade performance, reduce the shedding of blade wake vortices, reduce blade noise, and thereby reduce the noise of the entire axial flow fan. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0039] Figure 1 A schematic diagram of an axial flow fan provided according to some embodiments of the present invention;

[0040] Figure 2 A schematic diagram of a suction surface of a blade provided according to some embodiments of the present invention;

[0041] Figure 3 A schematic diagram of the arrangement of the first ribs of a blade according to some embodiments of the present invention;

[0042] Figure 4 for Figure 3 AA cross-sectional view of ;

[0043] Figure 5 A first projection schematic diagram of a blade and a hub on a first plane according to some embodiments of the present invention;

[0044] Figure 6 This is a schematic diagram of a second projection of a blade on a second plane according to some embodiments of the present invention.

[0045] The reference numerals in the accompanying drawings are described as follows:

[0046] 1-blade; 11-leading edge; 12-trailing edge; 13-blade root; 14-blade top; 15-first rib; 151-top; 16-second rib; 17-groove; 171-third rib; 172-fourth rib; 18-suction surface; 19-pressure surface;

[0047] 110-first projection; 111-first intersection point; 112-second intersection point; 113-first connecting line; 114-second connecting line; 115-third intersection point; 116-third connecting line; 117-fourth intersection point; 118-fourth connecting line;

[0048] 120-second projection; 121-fifth intersection; 122-sixth intersection; 123-first line; 124-first point; 125-second point; 126-second line; 127-third line; 128-fifth connecting line; 129-sixth connecting line;

[0049] 131-the seventh connection; 132-the eighth connection;

[0050] 2- Wheel hub. DETAILED DESCRIPTION

[0051] The technical scheme in the embodiment will be described clearly and completely below in conjunction with the accompanying drawings in the embodiment of the present invention. Obviously, the described embodiment is only a part of the embodiment of the present invention, not all of the embodiments. Based on the embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0052] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the scope of protection of the present invention.

[0053] like Figure 1 and Figure 2 As shown, some embodiments provide an axial flow fan, which includes: blades 1 and a hub 2, wherein the blades 1 are arranged on the hub 2.

[0054] exist Figure 1 In the illustrated embodiment, three blades 1 are disposed on the hub 2. The number of blades 1 disposed on the hub 2 is not limited to three, but may also be four, or five or more.

[0055] The blade 1 comprises a leading edge 11 and a trailing edge 12 which are arranged opposite to each other. The part where the blade 1 is connected to the hub 2 is a blade root 13. The part of the blade 1 opposite to the blade root 13 is a blade tip 14. The two opposite side surfaces of the blade 1 are a suction surface 18 and a pressure surface 19 respectively.

[0056] In some embodiments, the contour line of the trailing edge 12 is a Bezier curve.

[0057] The contour line of the trailing edge 12 adopts a Bezier curve, and the trailing edge 12 presents a spatial Bezier curve structure, which is an irregular curve structure. After testing, the trailing edge 12 presents a spatial Bezier curve structure, which can optimize blade performance, reduce the shedding of blade wake vortices, reduce noise, and thus reduce the noise of the entire fan compared to regular curve structures such as straight line structures or arc structures.

[0058] In some embodiments, Figure 5 As shown, the blade 1 and the hub 2 are projected on a first plane perpendicular to the axis of the hub 2 to form a first projection 110; in the first projection 110, the projection corresponding to the trailing edge 12 is a Bezier curve, which can reduce the trail vortex shedding of the blade 1 and reduce the fan noise.

[0059] In some embodiments, in the first projection 110 , the intersection of the leading edge 11 and the hub 2 is a first intersection 111 , the intersection of the axis of the hub 2 and the first plane is a second intersection 112 , and the line connecting the first intersection 111 and the second intersection 112 is a first line 113 .

[0060] A line connecting the second intersection point 112 and a point selected on the trailing edge 12 is a second line 114 , and an angle greater than zero is formed between the first line 113 and the second line 114 .

[0061] The closer a point selected on the trailing edge 12 is to the blade tip 14 , the smaller the angle between the first connecting line 113 and the second connecting line 114 is.

[0062] In some embodiments, in the first projection 110 , the intersection of the trailing edge 12 and the hub 2 is a third intersection 115 , a line between the third intersection 115 and the second intersection 112 is a third line 116 , and an angle between the third line 116 and the first line 113 is in the range of 90° to 120°.

[0063] In some embodiments, the intersection of the trailing edge 12 and the blade tip 14 is a fourth intersection 117 , a line between the fourth intersection 117 and the second intersection 112 is a fourth line 118 , and an angle between the fourth line 118 and the first line 113 is in the range of 30° to 60°.

[0064] exist Figure 5In the embodiment shown, seven sections S1 to S7 are made in sequence in the first projection 110 along the direction from the blade root 13 to the blade tip 14, which are the first section S1, the second section S2, the third section S3, the fourth section S4, the fifth section S5, the sixth section S6 and the seventh section S7. Of course, it is not limited to making seven sections, and six sections or eight sections can also be made. The seven sections S1 to S7 are all arc-shaped surfaces and are parallel to each other. The projection lines of the seven sections S1 to S7 in the first projection 110 are arc lines, and the centers of the arc lines are all the second intersection points 112.

[0065] Among them, the projection of the first section S1 coincides with the projection of the blade root 13, and the projection of the second section S7 coincides with the projection of the blade tip 14. The intersection of the first section S1 and the trailing edge 12 is the third intersection 115, and the intersection of the seventh section S7 and the trailing edge 12 is the fourth intersection 117. Similarly, the second section S2, the third section S3, the fourth section S4, the fifth section S5 and the sixth section S6 all have intersections with the trailing edge 12. The seven intersections of the trailing edge 12 and the seven sections S1 to S7 are connected to the second intersection 112 to form seven lines, and the angles between these seven lines and the first line 113 are θ1 to θ7, respectively. The angles θ1 to θ7 start from a common line and end at different lines. And the angles from θ1 to θ7 decrease successively.

[0066] according to Figure 5 As shown, the included angle between the third connecting line 116 and the first connecting line 113 is θ1, and the range of θ1 is 90° to 120°.

[0067] The included angle between the fourth connecting line 118 and the first connecting line 113 is θ7, and the range of θ7 is 30° to 60°.

[0068] like Figure 6 As shown, the blade 1 is projected on the second plane to form a second projection 120 ; in the second projection 120 , the projection corresponding to the trailing edge 12 is a Bezier curve.

[0069] The second plane is perpendicular to the first plane; in the first projection 110, the intersection of the leading edge 11 and the hub 2 is the first intersection 111, the intersection of the axis of the hub 2 and the first plane is the second intersection 112, and the line connecting the first intersection 111 and the second intersection 112 is the first line 113; the first line 113 is located in the second plane.

[0070] In some embodiments, in the second projection 120 , the intersection point of the trailing edge 12 and the blade root 13 is a fifth intersection point 121 , the intersection point of the trailing edge 12 and the blade tip 14 is a sixth intersection point 122 , and a line passing through the fifth intersection point 121 and perpendicular to the blade root 13 is a first line 123 .

[0071] In the second projection 120 , the trailing edge 12 has a first point 124 . The first point 124 is far from the first line 123 relative to the fifth intersection point 121 , and the first point 124 is close to the first line 123 relative to the sixth intersection point 122 .

[0072] In some embodiments, in the second projection 120 , the distance between the first point 124 and the blade root 13 is L1 , and the value range of L1 is 0.2R to 0.28R, where R is the radius of the axial flow fan.

[0073] In some embodiments, in the second projection 120 , the trailing edge 12 has a second point 125 , the second point 125 is farther from the blade root 13 than the first point 124 , and the second point 125 is farthest from the first line 123 compared to other points on the trailing edge 12 .

[0074] In some embodiments, in the second projection 120, the line passing through the first point 124 and parallel to the blade root 13 is the second line 126, the line passing through the second point 125 and parallel to the blade root 13 is the third line 127, and the distance between the second line 126 and the third line 127 is L2, and the value range of L2 is 0.28R to 0.43R, where R is the radius of the axial flow fan.

[0075] In some embodiments, in the second projection 120 , a line connecting the fifth intersection point 121 and the sixth intersection point 122 is a fifth line 128 , and an angle between the first line 123 and the fifth line 128 is α1 , and a value range of α1 is 0° to 20°.

[0076] In some embodiments, in the second projection 120 , the trailing edge 12 has a second point 125 , the second point 125 is farther from the blade root 13 than the first point 124 , and the second point 125 is farthest from the first line 123 compared to other points on the trailing edge 12 .

[0077] The line connecting the fifth intersection point 121 and the second point 125 is the sixth line 129 , the angle between the first line 123 and the sixth line 129 is α2 , the value range of α2 is 0° to 20°, and α2 is greater than α1.

[0078] In some embodiments, 1°<α2-α1<10°.

[0079] exist Figure 6 In the embodiment shown, seven sections S1 to S7 are sequentially made in the first projection 110 along the direction from the blade root 13 to the blade tip 14, which are the first section S1, the second section S2, the third section S3, the fourth section S4, the fifth section S5, the sixth section S6 and the seventh section S7. Of course, it is not limited to making seven sections, and six sections or eight sections can also be made. The seven sections S1 to S7 are all arc-shaped surfaces and are parallel to each other. The projections of the seven sections S1 to S7 in the second projection 120 are straight lines, and the straight lines are parallel to each other.

[0080] The projection of the first section S1 coincides with the projection of the blade root 13, and the projection of the second section S7 coincides with the projection of the blade tip 14. In the second projection 120, the intersection of the first section S1 and the trailing edge 12 is the fifth intersection 121, and the intersection of the seventh section S7 and the trailing edge 12 is the sixth intersection 122. The intersection of the third section S3 and the trailing edge 12 is the first point 124, and the intersection of the sixth section S6 and the trailing edge 12 is the second point 125. In the trailing edge 12, the arc change from the fifth intersection 121 to the first point 124 is relatively small and relatively stable, and the arc change from the first point 124 to the second point 125 is relatively large, and the second point 125 is farthest from the first line 123 compared with other points on the trailing edge 12.

[0081] The radial length from the fifth intersection point 121 to the first point 124 is L1, and the value range of L1 is 0.2R to 0.28R, where R is the radius of the axial flow fan.

[0082] The radial length from the first point 124 to the second point 125 is L2, and the selection range of L2 is 0.28R to 0.43R, where R is the radius of the axial flow fan.

[0083] The first line 123 is the normal line of each section S1 to S7, and the angle between the first line 123 and the fifth line 128 is α1, and the value range of α1 is 0° to 20°. The angle between the first line 123 and the sixth line 129 is α2, and the value range of α2 is 0° to 20°, and α2 is greater than α1. When 1°<α2-α1<10°, the blade has a better noise reduction effect.

[0084] In some embodiments, the common normal plane of the circumferential surfaces of the airflow inlet and the airflow outlet in the axial flow fan is the meridian plane of the impeller, and the axis of the impeller is also the axis of the meridian plane. Figure 6 It is also the projection of the blade 1 on the meridian plane. The projection of the trailing edge 12 on the meridian plane is a Bezier curve.

[0085] like Figure 3 As shown, the leading edge 11 is provided with a first rib 15, and the first rib 15 extends from the blade root 13 to the blade tip 14. The reinforcing rib structure provided on the leading edge 11 of the blade 1 is used to reduce blade tip vibration, increase blade stiffness, reduce resonance, and alleviate the vibration problem of the axial flow fan.

[0086] In some embodiments, the first rib 15 has an extension length of 0.85R to 0.9R to avoid resonance. R is the radius of the axial flow fan. The radius of the axial flow fan is R, and the first rib 15 extends from the hub 2 along the leading edge 11 to the blade tip 14.

[0087] like Figure 2 As shown, in some embodiments, the first rib 15 is disposed on the suction surface 18 of the blade 1 .

[0088] like Figure 3 and Figure 4 As shown, in some embodiments, the end of the first rib 15 close to the blade tip 14 is a top 151, the distance of the top 151 from the suction surface 18 to the pressure surface 19 of the blade 1 is a height H, the height H gradually decreases from the leading edge 11 to the trailing edge 12, the line between the highest point of the top 151 closest to the leading edge 11 and the lowest point closest to the trailing edge 12 is the seventh line 131, the line between the lowest point of the top 151 closest to the leading edge 11 and the lowest point closest to the trailing edge 12 is the eighth line 132, the angle between the seventh line 131 and the eighth line 132 is β, and the angle value range of β is 5° to 15°.

[0089] In some embodiments, the height H of the top 151 closest to the front edge 11 ranges from 2 mm to 8 mm, the length of the eighth connecting line 132 is L3, and the value range of L3 is 10 mm to 20 mm.

[0090] exist Figure 4 In the illustrated embodiment, the normal direction of the blade 1 surface is defined as the height H direction of the first rib 15 , and the direction along the blade surface, that is, the direction perpendicular to the blade normal, is the thickness L3 of the first rib 15 , tgβ=H / L3.

[0091] Preferably, the selection range of L3 is 10-20 mm, at which time the blade mode is optimal.

[0092] Preferably, the selection range of H is 2 to 8 mm, at which time the blade mode is optimal.

[0093] Preferably, the selection range of β is 5° to 15°, at which time the blade mode is optimal.

[0094] like Figure 2 As shown, the leading edge 11 is provided with a second rib 16, and the second rib 16 connects the hub 2 and the first rib 15. Since the leading edge 11 of the blade 1 is provided with the first rib 15 and the second rib 16, the overall strength of the blade 1 is increased, the rigidity of the blade 1 is improved, and it is not easily excited by low-frequency pressure pulsation, thereby reducing the probability of resonance and noise, and alleviating the noise problem of the axial flow fan.

[0095] The second rib 16 connects the first rib 15 and the hub 2. The second rib 16 and the first rib 15 have an overlapping portion on the suction surface 18 of the blade 1, which can further reduce the tip flutter and reduce the stress concentration at the blade root caused by the centrifugal force when the blade 1 runs at high speed.

[0096] In some embodiments, the extension length of the second rib 16 from the hub 2 to the blade tip 14 is 0.2R to 0.3R, where R is the radius of the axial flow fan.

[0097] In some embodiments, the second rib 16 runs through the suction surface 18 and the pressure surface 19 of the blade 1. The first rib 15 is only on the suction surface 18 of the blade 1, while the second rib 16 is on the suction surface 18 and the pressure surface 19 of the blade 1. The combination of the first rib 15 and the second rib 16 on the blade 1 can effectively reduce the tip vibration of the blade 1, and avoid the frequency band that may cause the blade to resonate by adjusting the natural frequency of the blade, thereby reducing the fan noise.

[0098] In some embodiments, the suction surface 18 of the blade 1 is provided with a groove 17, and the shape of the groove 17 matches the shape of the suction surface 18 along the blade 1. Matching here can be understood as: the shape of the groove 17 is consistent with the shape of the suction surface 18 of the blade 1, and the size of the groove 17 is smaller than the size of the suction surface 18 of the blade 1.

[0099] In some embodiments, a third rib 171 and a fourth rib 172 are provided in the groove 17, and the third rib 171 and the fourth rib 172 both extend in the direction from the leading edge 11 to the trailing edge 12. Of course, the groove 17 is not limited to having two ribs, and one rib, three ribs, four ribs or more ribs may be provided as needed.

[0100] In some embodiments, the third rib 171 is closer to the blade root 13 than the fourth rib 172 , the distance between the third rib 171 and the blade root 13 is 0.2R-0.3R, and the distance between the fourth rib 172 and the blade root 13 is 0.45R-0.55R, where R is the radius of the axial flow fan.

[0101] In some embodiments provided in the present disclosure, the trailing edge 12 of the blade 1 adopts a spatial Bezier curve structure, which can reduce the shedding of the trailing vortex of the blade and reduce the blade noise; the leading edge 11 of the blade 1 adopts a double reinforcement rib connection structure, which can effectively reduce the vibration of the blade tip, increase the overall stiffness and strength of the blade, and reduce the resonance of the fan assembly.

[0102] Some embodiments provide an air conditioner, which includes the above-mentioned axial flow fan. The axial flow fan provided by the present disclosure can reduce the noise of the air conditioner.

[0103] In the description of the present invention, it should be understood that the use of terms such as "first", "second", and "third" to limit components is only for the convenience of distinguishing the above components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0104] In addition, unless explicitly denied, the technical features of one embodiment may be beneficially combined with one or more other embodiments.

[0105] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the present invention, which should be included in the scope of the technical solution for protection of the present invention.

Claims

1. An axial flow fan, characterized in that: include: A blade (1) and a hub (2), wherein the blade (1) comprises a leading edge (11) and a trailing edge (12), and the contour line of the trailing edge (12) is a Bezier curve; the blade (1) is arranged on the hub (2); the portion where the blade (1) and the hub (2) are connected is a blade root (13), and the portion of the blade (1) opposite to the blade root (13) is a blade tip (14); The leading edge (11) is provided with a first rib (15), wherein the first rib (15) extends from the blade root (13) to the blade tip (14); The first rib (15) is arranged on the suction surface (18) of the blade (1); The end of the first rib (15) close to the blade tip (14) is a top end (151), the distance of the top end (151) from the suction surface (18) to the pressure surface (19) of the blade (1) is a height H, the height H gradually decreases along the direction from the leading edge (11) to the trailing edge (12), the line connecting the highest point of the top end (151) closest to the leading edge (11) and the lowest point closest to the trailing edge (12) is a seventh line (131), the line connecting the point of the top end (151) closest to the leading edge (11) and the point closest to the trailing edge (12) is an eighth line (132), the angle between the seventh line (131) and the eighth line (132) is β, and the angle value range of β is 5°~15°.

2. The axial flow fan according to claim 1, characterized in that: The blade (1) and the hub (2) are projected onto a first plane perpendicular to the axis of the hub (2) to form a first projection (110); in the first projection (110), the projection corresponding to the trailing edge (12) is a Bezier curve.

3. The axial flow fan according to claim 2, characterized in that: In the first projection (110), the intersection point of the leading edge (11) and the hub (2) is a first intersection point (111), the intersection point of the axis of the hub (2) and the first plane is a second intersection point (112), and the line connecting the first intersection point (111) and the second intersection point (112) is a first connecting line (113); A line connecting the second intersection point (112) and a point selected on the trailing edge (12) is a second line (114), and an angle greater than zero is formed between the first line (113) and the second line (114); The closer a point selected on the trailing edge (12) is to the blade tip (14), the smaller the angle between the first connecting line (113) and the second connecting line (114) is.

4. The axial flow fan according to claim 3, characterized in that: In the first projection (110), the intersection of the trailing edge (12) and the hub (2) is a third intersection (115), a line between the third intersection (115) and the second intersection (112) is a third line (116), and an angle between the third line (116) and the first line (113) is in the range of 90° to 120°.

5. The axial flow fan according to claim 4, characterized in that: The intersection of the trailing edge (12) and the blade tip (14) is a fourth intersection (117), a line between the fourth intersection (117) and the second intersection (112) is a fourth line (118), and an angle between the fourth line (118) and the first line (113) is in the range of 30° to 60°.

6. The axial flow fan according to claim 2, characterized in that: Projecting the blade (1) onto a second plane to form a second projection (120); in the second projection (120), the projection corresponding to the trailing edge (12) is a Bezier curve; The second plane is perpendicular to the first plane; in the first projection (110), the intersection of the leading edge (11) and the hub (2) is a first intersection (111), the intersection of the axis of the hub (2) and the first plane is a second intersection (112), and the line connecting the first intersection (111) and the second intersection (112) is a first line (113); the first line (113) is located in the second plane.

7. The axial flow fan according to claim 6, characterized in that: In the second projection (120), the intersection point of the trailing edge (12) and the blade root (13) is a fifth intersection point (121), the intersection point of the trailing edge (12) and the blade tip (14) is a sixth intersection point (122), and a line passing through the fifth intersection point (121) and perpendicular to the blade root (13) is a first line (123); In the second projection (120), the trailing edge (12) has a first point (124), the first point (124) is far away from the first line (123) relative to the fifth intersection (121), and the first point (124) is close to the first line (123) relative to the sixth intersection (122).

8. The axial flow fan according to claim 7, characterized in that: In the second projection (120), the distance between the first point (124) and the blade root (13) is , The value range of is 0.2R~0.28R, where R is the radius of the axial flow fan.

9. The axial flow fan according to claim 7, characterized in that: In the second projection (120), the trailing edge (12) has a second point (125), the second point (125) is farther away from the blade root (13) than the first point (124), and the second point (125) is farthest from the first line (123) compared to other points on the trailing edge (12).

10. The axial flow fan according to claim 9, characterized in that: In the second projection (120), a line passing through the first point (124) and parallel to the blade root (13) is a second line (126), a line passing through the second point (125) and parallel to the blade root (13) is a third line (127), and a distance between the second line (126) and the third line (127) is , The value range of is 0.28R~0.43R, where R is the radius of the axial flow fan.

11. The axial flow fan according to claim 7, characterized in that: In the second projection (120), the line connecting the fifth intersection point (121) and the sixth intersection point (122) is the fifth line (128), and the angle between the first line (123) and the fifth line (128) is , The value range is 0°~20°.

12. The axial flow fan according to claim 11, characterized in that: In the second projection (120), the trailing edge (12) has a second point (125), the second point (125) is farther from the blade root (13) than the first point (124), and the second point (125) is farthest from the first line (123) compared to other points on the trailing edge (12); The line connecting the fifth intersection point (121) and the second point (125) is the sixth line (129), and the angle between the first line (123) and the sixth line (129) is , The value range of is 0°~20°, and Greater than .

13. The axial flow fan according to claim 12, characterized in that: 。 14. The axial flow fan according to claim 1, characterized in that: The extension length of the first rib (15) is 0.85R-0.9R, where R is the radius of the axial flow fan.

15. The axial flow fan according to claim 1, characterized in that: The height H of the top end (151) closest to the front edge (11) ranges from 2 mm to 8 mm, and the length of the eighth connecting line (132) is , The value range is 10 mm~20 mm.

16. The axial flow fan according to claim 1, characterized in that: The front edge (11) is provided with a second rib (16), and the second rib (16) connects the wheel hub (2) and the first rib (15).

17. The axial flow fan according to claim 16, characterized in that: The extension length of the second rib (16) from the hub (2) to the blade tip (14) is 0.2R-0.3R, where R is the radius of the axial flow fan.

18. The axial flow fan according to claim 16, characterized in that: The second rib (16) runs through the suction surface (18) and the pressure surface (19) of the blade (1).

19. The axial flow fan according to claim 1, characterized in that: The suction surface (18) of the blade (1) is provided with a groove (17), and the shape of the groove (17) matches the shape of the suction surface (18) along the blade (1).

20. The axial flow fan according to claim 19, characterized in that: A third rib (171) and a fourth rib (172) are provided in the groove (17), and the third rib (171) and the fourth rib (172) both extend in a direction from the leading edge (11) to the trailing edge (12).

21. The axial flow fan according to claim 20, characterized in that: The third rib (171) is closer to the blade root (13) than the fourth rib (172); the distance between the third rib (171) and the blade root (13) is 0.2R~0.3R, and the distance between the fourth rib (172) and the blade root (13) is 0.45R~0.55R, where R is the radius of the axial flow fan.

22. An air conditioner, characterized in that: Comprising the axial flow fan as described in any one of claims 1 to 21.

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