Air conditioner

Abstract

Disclosed is an air conditioner, comprising a housing and an axial fan. The housing defines an air outlet. The axial fan comprises a central hub and at least one blade. The blade comprises a first side edge, a second side edge, a fourth side edge, and a third side edge. In the circumferential direction of the central hub, the first side edge and the second side edge are edges on two opposite sides of the blade. The fourth side edge is an edge on the side of the blade close to the central hub. The third side edge is an edge on the side of the blade away from the central hub. The straight line passing through any point on the circumferential section of the blade and perpendicular to the axis of the central hub is defined as a first straight line, the tangent line at any point on the circumferential section of the blade is defined as a second straight line, and the acute angle between the first straight line and the second straight line is defined as an angle β. In the direction from the fourth side edge to the third side edge, the angle β on the first side edge first increases, then decreases, and then increases again.

Description

air conditioner

[0001] This application claims priority to Chinese patent application No. 202311553614.8 filed on November 20, 2023, priority to Chinese patent application No. 202323147415.5 filed on November 21, 2023, and priority to Chinese patent application No. 202323137357.8 filed on November 20, 2023, all of which are incorporated by reference into this application. Technical Field

[0002] The present disclosure relates to the technical field of air treatment, and in particular to an air conditioner. Background Art

[0003] With the continuous advancement of technology and the improvement of people's living standards, air conditioners have become an indispensable appliance in daily life. Air conditioners rely on fans for both air intake and air discharge. For example, axial-flow fans are often used in air conditioner outdoor units. Axial-flow fans have a cylindrical center disk and multiple blades connected along its circumference. When the disk is driven to rotate, the blades rotate with it, driving the airflow.

[0004] Summary of the Invention

[0005] In one aspect, an air conditioner is provided, comprising a housing and an axial flow fan. The housing defines an air outlet. The axial flow fan corresponds to the air outlet and is disposed within the housing. The axial flow fan is configured to drive air flow. The axial flow fan includes a center disk and at least one blade. The at least one blade is connected to the outer periphery of the center disk. The blade includes a first side edge, a second side edge, a third side edge, and a fourth side edge. Along the circumference of the center disk, the first side edge and the second side edge are opposite edges of the blade. The fourth side edge is the edge of the blade closer to the center disk. The third side edge is the edge of the blade farther from the center disk. A first straight line is defined as a line perpendicular to the axis of the center disk, passing through any point on a circumferential cross-section of the blade; a second straight line is defined as a tangent to the point on the circumferential cross-section of the blade; and an acute angle β is defined as an angle β between the first straight line and the second straight line. In the direction from the fourth side edge to the third side edge, the angle β on the first side edge first increases, then decreases, and then increases again.

[0006] In another aspect, an air conditioner is provided, comprising a housing and an axial flow fan. The housing defines an air outlet. The axial flow fan corresponds to the air outlet and is disposed within the housing. The axial flow fan is configured to drive air flow. The axial flow fan includes a center disk and at least one blade. The at least one blade is connected to the outer periphery of the center disk. The blade includes a first side edge, a second side edge, a third side edge, and a fourth side edge. Along the circumference of the center disk, the first side edge and the second side edge are opposite edges of the blade. The fourth side edge is the edge of the blade proximal to the center disk. The third side edge is the edge of the blade distal to the center disk. Portions of the blade proximal to the second side edge and the third side edge are warped away from the air outlet. A first straight line is defined as a line passing through any point on a circumferential cross-section of the blade and perpendicular to the axis of the center disk. A second straight line is defined as a tangent line to any point on the circumferential cross-section of the blade. An acute angle between the first and second straight lines is defined as an angle β. In the direction from the fourth side edge to the third side edge, the angle β on the first side edge first increases, then decreases, and then increases again.

[0007] In another aspect, an air conditioner is provided, comprising a housing and an axial flow fan. The housing defines a housing cavity, and an air outlet is formed on a sidewall of the housing. The axial flow fan is disposed within the housing cavity, aligned with the air outlet, and located on the outlet side of the axial flow fan. The axial flow fan comprises a center disk and a plurality of blades. The center disk is connected to a drive mechanism and configured to rotate under the drive mechanism. The plurality of blades are spaced apart along the circumference of the center disk. Each of the plurality of blades comprises a first side edge, a second serrated portion, a second side edge, and a third side edge. The second serrated portion is disposed on the first side edge. Along the circumference of the center disk, the first and second side edges are opposite edges of each blade. The third side edge is the edge of each blade facing away from the center disk. The third side edge comprises a first line segment, a second line segment, and a third line segment. The second line segment connects the first and third line segments. The first line segment is located on a side of the second line segment close to the first side edge, and the third line segment is located on a side of the second line segment close to the second side edge. The first line segment and the third line segment are arc-shaped line segments, and the radius of the first line segment is greater than the radius of the third line segment.

[0008] In some embodiments, the radius of the first line segment is any value between 300 mm and 310 mm, and the radius of the third line segment is any value between 290 mm and 300 mm.

[0009] In some embodiments, the ratio of the straight-line distance between two points at the same blade height on the first side edge and the second side edge of any blade to the arc length between the two points is the primitive chord length of the blade. Any blade further includes a fourth side edge, which is an edge of the blade adjacent to the center disk. In a direction from the fourth side edge to the third side edge, the primitive chord length of the blade first increases and then decreases.

[0010] In some embodiments, the air conditioner further comprises an annular ring, an air guide ring, and a wind shield. The annular ring connects to the third side edges of the plurality of blades. The air guide ring is disposed radially outward from the annular ring; a gap is defined between the air guide ring and the annular ring. The wind shield is disposed within the gap and is configured to block airflow from the high-pressure area of ​​the pressure side of the axial fan through the gap to the low-pressure area of ​​the suction side of the axial fan.

[0011] In some embodiments, the wind shield includes a first protrusion and a second protrusion. The first protrusion is disposed radially outward from the annular ring and extends circumferentially of the annular ring. The second protrusion is disposed radially inward from the air guide ring and extends circumferentially of the air guide ring. The first protrusion and the second protrusion are spaced apart in the axial direction of the air guide ring.

[0012] In some embodiments, the annular ring, the center disk, and the plurality of blades are a single piece. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] FIG1A is a perspective view of an air conditioner according to some embodiments;

[0014] FIG1B is an exploded view of an air conditioner according to some embodiments;

[0015] FIG2 is a perspective view of an air conditioner according to some embodiments from another perspective;

[0016] 3 is a perspective view of a heat exchanger and an axial flow fan of an air conditioner according to some embodiments;

[0017] FIG4 is a perspective view of an air conditioner with a housing removed according to some embodiments;

[0018] FIG5 is a side view of an axial flow fan of an air conditioner according to some embodiments;

[0019] FIG6 is a perspective view of an axial flow fan of an air conditioner according to some embodiments;

[0020] FIG7 is a structural diagram of an axial flow fan of an air conditioner according to some embodiments;

[0021] FIG8 is a structural diagram of blades and a center disk of an air conditioner according to some embodiments;

[0022] FIG9 is a cross-sectional view of an axial flow fan of an air conditioner according to some embodiments;

[0023] FIG10 is a graph showing a first side edge β angle of an axial flow fan of an air conditioner according to some embodiments;

[0024] FIG11 is a perspective view of an axial flow fan of an air conditioner according to some embodiments from another perspective;

[0025] FIG12 is a graph showing a second side edge β angle of an axial flow fan of an air conditioner according to some embodiments;

[0026] FIG13 is a graph showing a third side edge β angle of an axial flow fan of an air conditioner according to some embodiments;

[0027] FIG14 is a perspective view of an axial flow fan of an air conditioner according to some embodiments from another perspective;

[0028] FIG15 is a perspective view of an axial flow fan of an air conditioner according to some embodiments from another perspective;

[0029] FIG16 is a perspective view of a plurality of blades of an axial flow fan of an air conditioner when stacked according to some embodiments;

[0030] FIG17 is a structural diagram of blades and an annular ring of an air conditioner according to some embodiments;

[0031] FIG18 is a perspective view of an axial flow fan and an air guide ring of an air conditioner according to some embodiments;

[0032] FIG19 is a perspective view of an axial flow fan and an air guide ring of an air conditioner according to some embodiments from another perspective;

[0033] FIG20 is a cross-sectional view of an axial flow fan and an air guide ring of an air conditioner according to some embodiments;

[0034] FIG21 is a partial enlarged view of portion X in FIG20 ;

[0035] FIG22 is a perspective view of another axial flow fan of an air conditioner according to some embodiments;

[0036] FIG23 is a partial enlarged view of portion E1 in FIG22;

[0037] FIG24 is a partial enlarged view of portion E2 in FIG22 ;

[0038] FIG25 is a structural diagram of another axial flow fan of an air conditioner according to some embodiments;

[0039] FIG26 is another structural diagram of another axial flow fan of an air conditioner according to some embodiments;

[0040] FIG27 is a cross-sectional view taken along the FF direction in FIG25 ;

[0041] FIG28 is a structural diagram of blades and a center plate of an air conditioner according to some embodiments;

[0042] FIG29 is a perspective view of another axial flow fan and an air guide ring of an air conditioner according to some embodiments;

[0043] FIG30 is a structural diagram of another axial flow fan and air guide ring of an air conditioner according to some embodiments;

[0044] FIG31 is a cross-sectional view taken along the GG direction in FIG30 ;

[0045] FIG32 is a partial enlarged view of portion E3 in FIG31 ;

[0046] FIG33 is a perspective view of another axial flow fan and a wind shield of an air conditioner according to some embodiments;

[0047] FIG34 is a cross-sectional view of an air guide ring of an air conditioner according to some embodiments;

[0048] FIG35 is a partial enlarged view of portion E4 in FIG34 . DETAILED DESCRIPTION

[0049] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in some embodiments of the present disclosure. Obviously, the embodiments described are only some embodiments of the present disclosure, not all embodiments. Based on the embodiments provided by the present disclosure, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of the present disclosure.

[0050] Unless the context requires otherwise, throughout the specification and claims, the term "comprise" and its other forms, such as the third person singular form "comprises" and the present participle form "comprising", are to be interpreted as open and inclusive, that is, "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "example", "specific example" or "some examples" are intended to indicate that the particular features, structures, materials or characteristics associated with the embodiment or example are included in at least one embodiment or example of the present disclosure. The schematic representation of the above terms does not necessarily refer to the same embodiment or example. In addition, the particular features, structures, materials or characteristics may be included in any one or more embodiments or examples in any appropriate manner.

[0051] In the following, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present disclosure, unless otherwise specified, "plurality" means two or more.

[0052] When describing some embodiments, the word "connected" and its derivatives may be used. The term "connected" should be understood in a broad sense. For example, "connected" can mean fixed connection, detachable connection, or integration; it can be directly connected or indirectly connected through an intermediate medium.

[0053] “At least one of A, B and C” has the same meaning as “at least one of A, B or C” and both include the following combinations of A, B and C: A only, B only, C only, the combination of A and B, the combination of A and C, the combination of B and C, and the combination of A, B and C.

[0054] “A and / or B” includes the following three combinations: A only, B only, and a combination of A and B.

[0055] The use of "adapted to" or "configured to" herein is intended to be open and inclusive language that does not exclude devices adapted or configured to perform additional tasks or steps.

[0056] As used herein, "about," "substantially," or "approximately" includes the stated value and an average value that is within an acceptable range of deviation from the particular value as determined by one of ordinary skill in the art taking into account the measurements in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system).

[0057] As used herein, "parallel", "perpendicular", and "equal" include the situations described and situations similar to the situations described, and the range of the similar situations is within an acceptable deviation range, wherein the acceptable deviation range is as determined by a person of ordinary skill in the art taking into account the measurement in question and the errors associated with the measurement of the specific quantity (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallelism and approximate parallelism, wherein the acceptable deviation range of approximate parallelism can be, for example, a deviation within 5°; "perpendicular" includes absolute perpendicularity and approximate perpendicularity, wherein the acceptable deviation range of approximate perpendicularity can also be, for example, a deviation within 5°. "Equal" includes absolute equality and approximate equality, wherein the acceptable deviation range of approximate equality can be, for example, that the difference between the two equals is less than or equal to 5% of either one.

[0058] Exemplary embodiments are described herein with reference to cross-sectional and / or plan views that are idealized exemplary drawings. In the drawings, the thicknesses of layers and regions are exaggerated for clarity. Therefore, variations in shape relative to the drawings due to, for example, manufacturing techniques and / or tolerances are contemplated. Therefore, the exemplary embodiments should not be construed as limited to the shapes of the regions shown herein, but rather include deviations in shape due to, for example, manufacturing. For example, an etched region shown as a rectangle will typically have curved features. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to illustrate the actual shape of regions of the device and are not intended to limit the scope of the exemplary embodiments.

[0059] Air conditioners rely on fans for both air intake and exhaust. For example, the fan commonly used in an air conditioner's outdoor unit is an axial-flow fan. This fan features a cylindrical center disk and multiple blades connected along its circumference. When the disk is driven to rotate, the blades rotate with it, driving the airflow.

[0060] Typically, the working area on the blades of an axial flow fan used to push the airflow is located in the middle of the blade and close to the third side edge of the blade. This will cause the airflow to separate from the blade from the middle of the blade prematurely, thereby reducing the working efficiency of the axial flow fan and increasing the working noise.

[0061] Based on this, some embodiments of the present disclosure provide an air conditioner, which includes an outdoor unit and an indoor unit, wherein the outdoor unit and the indoor unit cooperate to adjust the temperature and humidity of indoor air.

[0062] For example, when an air conditioner is operating in cooling mode, the compressor in the outdoor unit compresses the gaseous refrigerant into a high-temperature, high-pressure gaseous refrigerant. This high-temperature, high-pressure gaseous refrigerant then exchanges heat with the outdoor unit's heat exchanger, transforming it into a room-temperature, high-pressure liquid refrigerant. The room-temperature, high-pressure liquid refrigerant then enters the indoor unit, where it exchanges heat with the heat exchanger, absorbing heat and lowering the air temperature inside the unit. The indoor unit's fan then directs the cooler air out through the grille, cooling the indoor air.

[0063] When the air conditioner is operating in heating mode, the compressor in the outdoor unit compresses the gaseous refrigerant into a high-temperature, high-pressure gaseous refrigerant. This high-temperature, high-pressure gaseous refrigerant exchanges heat with the indoor unit's heat exchanger, condensing and liquefying into a room-temperature, high-pressure liquid refrigerant. This heat releases heat, raising the temperature of the air inside the indoor unit. The indoor unit's fan then directs the warmer air through the grille, raising the indoor air temperature. The room-temperature, high-pressure liquid refrigerant is then reduced in pressure by the throttling device and enters the outdoor unit's heat exchanger. The room-temperature, high-pressure liquid refrigerant evaporates, absorbing heat and transforming into a low-temperature, low-pressure gaseous refrigerant. This low-temperature, low-pressure gaseous refrigerant then enters the outdoor unit's compressor, beginning the next cycle.

[0064] In some embodiments, as shown in FIG1A and FIG2 , the air conditioner 1 includes a housing 10. The housing 10 forms the exterior of the air conditioner 1 (e.g., an outdoor unit) and is generally rectangular. The housing 10 includes a front wall 11 forming the front structure of the air conditioner 1, a rear wall 12 forming the rear structure of the air conditioner 1, a top wall 13 forming the top structure of the air conditioner 1, a bottom wall 14 forming the bottom structure of the air conditioner 1, and a left wall 15 and a right wall 16 forming the left and right side structures of the air conditioner 1.

[0065] 1A and 2 , the air conditioner 1 further includes a main air inlet 121 . The main air inlet 121 is formed on the rear wall 12 . For example, a portion of the rear wall 12 is opened to form the main air inlet 121 .

[0066] In some embodiments, as shown in Figures 1A and 2, the air conditioner 1 further includes a side air inlet 151. The side air inlet 151 is formed on the left wall 15. For example, a portion of the left wall 15 is opened to form the side air inlet 151.

[0067] In some embodiments, as shown in FIG1A , the air conditioner 1 further includes a grille 17. A portion of the front wall 11 is open to form an air outlet 171. The grille 17 is mounted at the air outlet 171 and is fixedly connected to the housing 10. The grille 17 is configured to protect the axial flow fan to improve the reliability and stability of the axial flow fan's operation.

[0068] For example, external air can enter the housing 10 from the side air inlet 151 and the main air inlet 121 and flow out of the housing 10 from the air outlet 171. The air flows through the grille plate 17 during the process of flowing through the air outlet 171 and being discharged outside the housing 10.

[0069] In some embodiments, as shown in FIG3 , the air conditioner 1 further includes a heat exchanger 20 . The heat exchanger 20 is disposed in the housing 10 and corresponds to the side air inlet 151 and the main air inlet 121 .

[0070] For example, the heat exchanger 20 includes a first heat exchange portion 21 and a second heat exchange portion 22. The first heat exchange portion 21 corresponds to the position of the side air inlet 151 and extends in the front-to-back direction as shown in FIG3 . The second heat exchange portion 22 is connected to the first heat exchange portion 21. The second heat exchange portion 22 corresponds to the position of the main air inlet 121 and extends in the left-to-right direction as shown in FIG3 .

[0071] In some embodiments, the heat exchanger 20 includes a plurality of heat transfer tubes, which are spaced apart and arranged in a vertical direction of the air conditioner 1. The heat transfer tubes are configured to transfer refrigerant.

[0072] In some embodiments, the heat exchanger 20 further includes a plurality of fins, which are arranged side by side between the plurality of heat transfer tubes and are configured to expand the contact area between the refrigerant and the air.

[0073] It should be noted that the heat transfer pipe of the outdoor unit heat exchanger 20 is connected to the compressor, the indoor unit heat exchanger, the expansion valve, etc. through piping, thereby constituting the refrigerant circuit of the air conditioner 1 .

[0074] In some embodiments, as shown in Figures 3 and 4, the air conditioner 1 further includes an axial flow fan 30 and a motor bracket 50. The motor bracket 50 is disposed in the housing 10 and is fixedly connected to the housing 10. For example, the motor bracket 50 is located in the housing 10 and is close to the front side of the housing 10.

[0075] The axial flow fan 30 is disposed in the motor bracket 50 and is located between the heat exchanger 20 and the air outlet 171. The axial flow fan 30 is configured to discharge the high temperature air in the housing 10 to the outside of the housing 10 through the air outlet 171.

[0076] In some embodiments, as shown in FIG. 1B , a housing 10 defines a receiving cavity 18 , and the axial flow fan 30 is located in the receiving cavity 18 .

[0077] In some embodiments, the air conditioner 1 further includes a motor. The motor is mounted on a motor bracket 50, and an output shaft of the motor is connected to the axial flow fan 30. The motor is configured to drive the axial flow fan 30 to rotate via the output shaft. For example, the axial flow fan 30 is located in front of the motor, and the motor provides rotational driving force to the axial flow fan 30.

[0078] It can be understood that the air conditioner 1 draws in air from the air inlet (including the main air inlet and the side air inlet) of the shell 10 through the rotational movement of the axial fan 30. The inhaled air enters the heat exchanger 20, exchanges heat with the refrigerant flowing inside the heat exchanger 20 when passing through the heat exchanger 20, and then is blown out from the air outlet 171 of the shell 10.

[0079] In some embodiments, as shown in FIG4 , the air conditioner 1 further includes an air guide ring 40 . The air guide ring 40 is generally cylindrical and extends in the front-to-back direction of the air conditioner 1 . For example, the front end of the air guide ring 40 corresponds to the grille plate 17 and is connected to the front wall 11 . The air guide ring 40 is located radially outward from the axial flow fan 30 and is configured to guide the airflow direction of the axial flow fan 30 . The air guide ring 40 is located in front of the axial flow fan 30 .

[0080] In some embodiments, the air guide ring 40 and the front wall 11 are an integral part, or the air guide ring 40 and the front wall 11 are separate parts.

[0081] In some embodiments, as shown in FIG5 , the axial flow fan 30 rotates about a central axis A (i.e., a rotation axis A) to generate airflow. The air inlet side (rear side) of the axial flow fan 30 is the upstream side, and the air outlet side (front side) of the axial flow fan 30 is the downstream side. The airflow flows from the downstream side to the upstream side of the axial flow fan 30.

[0082] In some embodiments, as shown in Figures 6 and 7, the axial flow fan 30 includes a center disk 31 and at least one blade 32. The at least one blade 32 is connected to the outer periphery of the center disk 31. For example, the at least one blade 32 includes a plurality of blades 32. The central axis of the center disk 31 coincides with the rotation axis A, and the center disk 31 is configured to be connected to the output end of the driving mechanism that drives the axial flow fan 30 to rotate, so as to drive the axial flow fan 30 to rotate. For example, the power output shaft of the motor is connected to the center disk 31 to drive the axial flow fan 30 to rotate. The plurality of blades 32 are arranged at intervals along the circumference of the center disk 31. The plurality of blades 32 are fixedly connected to the center disk 31.

[0083] For example, the blades 32 extend radially outward from the outer periphery of the center disk 31 .

[0084] It should be noted that some embodiments of the present disclosure use the axial flow fan 30 as an example to include three blades 32. However, the axial flow fan 30 is not limited to including three blades 32. In some embodiments, the axial flow fan 30 includes two, four or more blades 32, and the present disclosure does not limit this.

[0085] In some embodiments, as shown in FIG. 6 and FIG. 7 , the axial flow fan 30 rotates along a rotation direction B. As shown in FIG.

[0086] For example, in the angle from the front side to the rear side, the rotation direction B is counterclockwise, that is, the axial flow fan 30 rotates in the counterclockwise direction.

[0087] For example, in terms of the angle from the rear side to the front side, the rotation direction B is a clockwise direction, that is, the axial flow fan 30 rotates in the clockwise direction.

[0088] In some embodiments, as shown in Figures 6 and 7 , the blade 32 includes a first side edge 321. With reference to the rotational direction B of the axial flow fan 30, the first side edge 321 is a side edge of the blade 32 on the forward side. The first side edge 321 includes a first end proximal to the center plate 31 and a second end distal to the center plate 31.

[0089] In some embodiments, as shown in Figures 6 and 7 , the blade 32 further includes a second side edge 322. With reference to the rotational direction B of the axial flow fan 30, the second side edge 322 is the side edge of the blade 32 opposite the first side edge 321. The second side edge 322 includes a first end proximal to the center plate 31 and a second end distal to the center plate 31.

[0090] In some embodiments, along the circumference of the center disk 31 , the first side edge and the second side edge are opposite side edges of the blade 32 .

[0091] 7 , in the rotation direction B, the first side edge 321 is located on the forward side of the second side edge 322 , and in the airflow direction C, the first side edge 321 is located upstream of the second side edge 322 .

[0092] In some embodiments, as shown in Figures 6 and 7 , the blade 32 further includes a third side edge 323 and a fourth side edge 324. The third side edge 323 is the edge of the blade 32 that is away from the center disk 31 (i.e., the outer edge). The third side edge 323 is not connected to the center disk 31 and extends at an angle relative to the rotation axis A. The fourth side edge 324 is the edge of the blade 32 that is connected to the center disk 31 (i.e., the inner edge). The fourth side edge 324 extends at an angle relative to the rotation axis A.

[0093] In some embodiments, the radius of the middle disk 31 is defined as R1, the radius of the third side edge 323 is defined as R2, and the distance between any point on the blade 32 located between the fourth side edge 324 and the third side edge 323 (i.e., between R1 and R2) and the rotation axis A of the axial fan 30 is R'. In this case, the blade height can be defined as (R'-R1) / (R2-R1). It should be noted that the blade height is a set of multiple points on the blade 32 that are at the same distance from the rotation axis A, and the figure formed by these points is an arc with the rotation axis A as the center. For example, the radius of 0% blade height is R1, and the radius of 100% blade height is R2. For ease of understanding, 30% blade height, 60% blade height, 80% blade height, 90% blade height, etc. are illustrated in Figure 8.

[0094] In some embodiments, as shown in FIG9 , a cross section of a blade at any height (i.e., parallel to the fore-aft direction) is defined as the circumferential cross section of the blade. In other words, a cross section obtained by cutting the blade through an arc defined by extending an arc line at any height of the blade along the fore-aft direction is defined as the circumferential cross section of the blade.

[0095] In any circumferential cross-section of blade 32, any point on the circumferential cross-section is denoted as Q. A line perpendicular to the rotation axis A and passing through point Q is defined as first line L1. A tangent line at point Q is defined as second line L2. The acute angle formed by the intersection of first line L1 and second line L2 is defined as angle β. The distance from the second side edge Q1 of the cross-section (i.e., the end Q1 closest to the second side edge) to point Q is denoted as Ln. The distance from the second side edge Q1 to the first side edge Q2 (i.e., the end of the cross-section closest to the first side edge) is L. The ratio of Ln to L is defined as the chord length ratio.

[0096] It is understood that by changing the shape and structure of the blade 32, the working position of the blade 32 can be changed. For example, the working position can be moved toward the second side edge of the blade, thereby avoiding the problem of premature separation of the airflow from the blade. In the following embodiments, the size and variation of the β angle on multiple major edges of the blade 32 will be used to approximately illustrate the shape and structure of the blade 32.

[0097] In some embodiments, a curve showing how the β angle at the first side edge of blade 32 varies with blade height (%) is shown in FIG10 . In FIG10 , the β angle at the first side edge is plotted on the vertical axis, and blade height (%) is plotted on the horizontal axis. That is, the β angle at the first side edge at 0% blade height is the β angle at the first end of the first side edge, and the β angle at the first side edge at 100% blade height is the β angle at the second end of the first side edge. In FIG10 , the relationship between the β angle at the first side edge and blade height is represented as a first side edge β angle curve M.

[0098] In the linear graph of the first side edge β angle, from the inner edge side to the outer edge side (ie, from the first end to the second end of the first side edge), the first side edge β angle first increases, then decreases, and then increases again.

[0099] The above arrangement enables the working position of the blade to move closer to the second side edge, thereby effectively avoiding the problem of premature separation of the airflow from the blade, which is beneficial to improving the working efficiency of the blade and reducing noise.

[0100] In some embodiments, as shown in FIG10 , the first side edge β angle curve M includes an upwardly convex first portion 61 and a downwardly concave second portion 62. That is, within the blade height range corresponding to the first convex portion 61 (e.g., 10% to 30% of the blade height), the blade 32 convexly projects forward at the first side edge 321. And within the blade height range corresponding to the second convex portion 62 (e.g., 40% to 70% of the blade height), the blade 32 concavely projects rearward at the first side edge 321. The first convex portion 61 is closer to the inner edge than the second convex portion 62.

[0101] In some embodiments, the slope of the ascending side of the first protrusion 61 is gentler than the slope of the descending side of the second protrusion 62. A first inflection point 63 of the first side edge angle β is formed on the first protrusion 61. A second inflection point 64 of the first side edge angle β is formed on the second protrusion 62. The second inflection point 64 is located between 50% and 70% of the blade height.

[0102] It can be understood that at the leaf height corresponding to the first inflection point 63 , the protrusion of the blade 32 at the first side edge 321 is the greatest. At the leaf height corresponding to the second inflection point 64 , the protrusion of the blade 32 at the first side edge 321 is the least.

[0103] In some embodiments, as shown in Figure 10, a line connecting the inner and outer edges of the first side edge β angle curve M is a reference line I, which is horizontal or nearly horizontal. The first protrusion 61 is located above the reference line I, and the second protrusion 62 is located below the reference line I. The distance between the second inflection point 64 and the reference line I is greater than the distance between the first inflection point 63 and the reference line I. It is understood that setting a larger rate of change of the β angle near the outer edge of the first side edge can shift the blade's working position toward the second side edge.

[0104] In some embodiments, as shown in Figures 6 and 7 , blade 32 includes a positive pressure surface 325 and a negative pressure surface 326 disposed opposite each other. Positive pressure surface 325 is the front side of blade 32, and negative pressure surface 326 is the rear side of blade 32. With reference to the airflow direction C, positive pressure surface 325 is located downstream of negative pressure surface 326, and negative pressure surface 326 is located upstream of positive pressure surface 325. In other words, positive pressure surface 325 is the side of blade 32 closer to the air outlet, and negative pressure surface 326 is the side of blade 32 farther from the air outlet.

[0105] Referring to Figure 11 , the shape change of the first side edge is shown by the dashed line in FIG11 . As the blade height increases from low to high, the first side edge 321 first bulges toward the negative pressure surface 326 and then bulges toward the positive pressure surface 325 . In other words, as the blade moves from the inner edge to the outer edge, the first side edge first concave away from the air outlet and then bulges toward the air outlet. The portion of the first side edge 321 near the third side edge 323 appears to be warped toward the negative pressure surface.

[0106] In some embodiments, as shown in FIG12 , a curve showing how the β angle at the second side edge of a blade 32 changes with blade height (%) is shown. In FIG12 , the β angle at the second side edge is plotted on the vertical axis, and blade height (%) is plotted on the horizontal axis. That is, the β angle at the second side edge at 0% blade height corresponds to the β angle at the first end of the second side edge, and the β angle at the second side edge at 100% blade height corresponds to the β angle at the second end of the second side edge. In FIG12 , the relationship between the β angle at the second side edge and blade height is represented as a second side edge β angle curve N.

[0107] In the linear graph of the second side edge β angle, the second side edge β angle gradually decreases from the inner edge side to the outer edge side (ie, from the first end to the second end of the second side edge).

[0108] With the above arrangement, the working area of ​​the blades can be expanded, thereby improving the working efficiency of the axial flow fan 30 and reducing the noise generated when the axial flow fan 30 is working.

[0109] In some embodiments, as shown in FIG12 , the second side edge β angle curve N includes a first region 71, a second region 72, and a third region 73. The second region 72 is located in the middle of the second side edge β angle curve N and smoothly connects to the first region 71. The slope of the first region 71 is greater than the slope of the second region 72. The third region 73 is the portion of the second side edge β angle curve N close to the inner edge and is connected to the second region 72.

[0110] 11 , the portion of the blade 32 near the third side edge 323 and the second side edge 322 is warped toward the suction surface 326 (i.e., toward the rear). For example, the blade 32 further includes a warped portion 74 disposed at the corner formed by the third side edge 323 and the second side edge 322. The warped portion 74 warps toward the suction surface 326 to cause the angle β of the first region 71 to change.

[0111] Testing has shown that the axial flow fan 30 in some embodiments of the present disclosure, when outputting a preset air volume, has higher static pressure efficiency and lower specific noise compared to the axial flow fan in the comparative example. For example, when the air conditioner is operating in cooling mode, the axial flow fan 30 is typically set to operate at a first preset air volume. In this case, the axial flow fan 30 in some embodiments of the present disclosure has higher static pressure efficiency and lower specific noise.

[0112] It can be understood that some embodiments of the present disclosure, by setting the portion of the third side edge 323 of the blade close to the second side edge 322 to bend toward the negative pressure surface 326, and constructing the first side edge 321 of the blade 32 to be wavy, the working area of ​​the blade is moved toward the second side edge, thereby expanding the working area of ​​the blade, improving the performance of the fan and reducing noise.

[0113] In some embodiments, a curve showing how the β angle at the third side edge of the blade 32 changes with the chord length ratio is shown in FIG13 . In FIG13 , the β angle at the third side edge is taken as the vertical axis, and the chord length ratio is taken as the horizontal axis. In FIG13 , the relationship between the β angle at the first side edge and the blade height is represented as the third side edge β angle curve J. The β angle value at the intersection of the third side edge and the second side edge is the first end of the curve J (i.e., the left end in FIG13 ), and the β angle value at the intersection of the third side edge and the first side edge is the second end of the curve J (i.e., the right end in FIG13 ). In the third side edge β angle linear graph, the third side edge β angle continuously decreases from the second side edge to the first side edge.

[0114] The third side edge β angle curve J can be divided into a fourth region 81 and a fifth region 82. The fourth region 81 is the third side edge β angle curve closer to the second side edge portion of the blade, and the fourth region 81 is the third side edge β angle curve closer to the first side edge portion of the blade. The slope of the fourth region 81 is greater than that of the fifth region 82.

[0115] It can be understood that a greater slope of the curve indicates a greater change in the β angle, which in turn indicates a greater structural change at the third side edge of the blade, i.e., a greater slope at the third side edge of the blade. In the linear graph of the β angle at the third side edge, the area with the largest slope represents the fan's primary work area. Therefore, some embodiments of the present disclosure position the blade's maximum slope near the second side edge, placing the fan's work area closer to the second side edge and preventing premature separation of the airflow over the blade.

[0116] In some embodiments, as shown in Figures 6 to 8, the blade 32 further includes a first serration 327. The first serration 327 includes a plurality of notches 3271 spaced apart and arranged on the second side edge 322. Any two adjacent notches 3271 are defined as first notches 3272, and any two adjacent notches 3271 closer to the third side edge than the first notches 3272 are defined as second notches 3273. The distance between two adjacent second notches 3273 is greater than the distance between two adjacent first notches 3272. For example, the first serration 327 is configured in a bird's wing shape.

[0117] With the above arrangement, the working area on the surface of the blade 32 can be increased, the vortex on the surface of the blade 32 can be reduced, and the noise generated by the axial flow fan can be reduced while the air volume of the axial flow fan is increased.

[0118] In some embodiments, as shown in FIG14 , the blade 32 further includes a protrusion 328. The protrusion 328 is disposed on the suction surface 326 of the blade 32. The protrusion 328 is disposed near the first side edge 321 and extends along the extension direction of the first side edge 321. The width and thickness of the protrusion 328 gradually increase as it approaches the fourth side edge.

[0119] It is understandable that when the fan is running at high speed, due to the action of centrifugal force, stress will be concentrated at the root of the blade (i.e., the fourth side edge 324). Therefore, by providing the protrusion 328, the stress at the root of the blade can be reduced, thereby improving the force condition of the root of the blade at high speed, which is beneficial to improving the reliability and durability of the blade 32. In some embodiments, as shown in Figures 14 and 15, the middle disk 31 includes a cylindrical outer ring portion 311 and a support portion 312 connected to the outer ring portion 311. The blade 32 is connected to the outer peripheral surface of the outer ring portion 311, which is beneficial to improving the connection strength between the blade 32 and the middle disk 31, and is beneficial to improving the reliability of the axial flow fan.

[0120] 14 and 15 , the middle plate 31 further includes an opening 313. The opening 313 is provided at one end of the outer ring portion 311 facing the air outlet 171 and is configured to reduce the weight of the axial flow fan.

[0121] For example, the center disk 31 includes a plurality of openings 313 that are spaced apart along the circumference of the center disk 31. For example, the number of openings 313 corresponds to the number of blades 32, and any one of the plurality of openings 313 corresponds to one blade 32 in the radial direction of the center disk 31.

[0122] For example, the axial flow fan 30 includes three blades 32 , and the center plate 31 includes three openings 313 . The position of one opening 313 corresponds to one blade 32 .

[0123] In some embodiments, as shown in FIG15 , the opening 313 is surrounded by a first enclosing portion 314 and a second enclosing portion 315. At least a portion of the first enclosing portion 314 is parallel to the fourth side edge 324 of the blade 32, and at least a portion of the second enclosing portion 315 is parallel to the axis of the center disk 31. A circular arc forms the transition between the first enclosing portion 314 and the second enclosing portion 315.

[0124] The distance between the first enclosing portion 314 and the fourth side edge 324 is 0.1 to 0.3 times R1. This allows the area of ​​the opening 313 to be increased while maintaining the structural strength of the center plate 31. For example, the distance between the first enclosing portion 314 and the fourth side edge 324 can be 0.1, 0.2, or 0.3 times R1.

[0125] In some embodiments, as shown in FIG15 , the support portion 312 includes at least one sub-support portion 3121, and the at least one sub-support portion 3121 is located between two adjacent openings 313. This can reduce the weight of the center disk, save usage, and reduce costs.

[0126] In some embodiments, as shown in Figures 14 to 16 , the center disk 31 further includes a groove 317. The groove 317 is disposed on the outer ring portion 311 and is open radially outward of the center disk 31. The groove 317 is positioned near the air inlet. Along the circumference of the center disk 31, the groove 317 is located between two blades 32.

[0127] It is understood that when transporting multiple axial-flow fans, two axial-flow fans need to be stacked one on top of the other. In this case, the sub-support portion 3121 of the lower axial-flow fan can be inserted into the groove portion 317 of the upper axial-flow fan, thereby reducing the height of the stacked axial-flow fans and increasing the transport volume. In addition, compared to the groove portion 317 that penetrates the side wall of the outer ring portion 311, the blind hole groove portion 317 has greater strength.

[0128] In some embodiments, the support portion 312 is conical, with its apex near the air outlet and its open end facing the air inlet. This ensures the structural strength of the support portion 312 while reducing the weight of the center plate 31. In some embodiments, the support portion 312 can also be cylindrical or frustum-conical, although this disclosure is not limited thereto.

[0129] In some embodiments, due to the limitation of the space inside the shell 10, the axial size of the air guide ring 40 is limited. Therefore, in the circumferential direction of the air guide ring 40, the air guide ring 40 cannot completely surround the blades 32 of the axial fan 30. That is to say, a part of the axial fan 30 (i.e., the first part 329) is located on the inner side of the air guide ring 40, and the other part of the axial fan 30 (i.e., the second part) is outside the air guide ring 40. In this way, air leakage will occur at the top of the blade, resulting in a decrease in the working efficiency of the axial fan and an increase in the working noise.

[0130] 17 to 19 , the axial flow fan 30 in some embodiments of the present disclosure further includes an annular ring 33 connected to the outer periphery of the blades 32 . The annular ring 33 is located at the rear side of the air guide ring 40 .

[0131] For example, referring to FIG17 , the first portion 329 of the blade 32 is located on the inner side of the air guide ring 40 , and the second portion of the blade 32 is located inside the annular ring 33 , thereby avoiding air leakage at the top of the blade 32 , thereby helping to improve the working efficiency of the axial flow fan 30 and reduce noise.

[0132] In some embodiments, an end of the annular ring 33 close to the air outlet 171 is located radially inward of the air guide ring 40 .

[0133] It is understood that since the axial fan 30 and the air guide ring 40 are not structurally connected but only positionally related, any assembly error in any component of the air conditioner 1 may result in the first portion 329 of the blade 32 not being located within the air guide ring 40, thereby potentially failing to resolve the problem of air leakage at the top of the blade. To this end, by positioning the front end portion of the annular ring 33 within the air guide ring 40, the first portion 329 of the blade 32 is ensured to be located within the air guide ring 40.

[0134] In some embodiments, as shown in FIG. 20 and FIG. 21 , the radial gap between the air guide ring 40 and the first portion 329 is recorded as A1, and the radial gap between the air guide ring 40 and the annular ring 33 is recorded as A2. The width of A1 is equal to the width of A2.

[0135] In this way, the radial gap between the air inlet end of the air guide ring 40 and the axial flow fan can be reduced, thereby helping to reduce air leakage and improve the working efficiency of the axial flow fan 30.

[0136] In some embodiments, the annular ring 33 and the blades 32 are integrally formed. For example, the annular ring 33 and the blades 32 are integrally formed by injection molding. The portion of the blades 32 near the air inlet is not exposed from the annular ring 33, ensuring that the blades 32 are located radially inward of the annular ring 33 and the air guide ring 40.

[0137] In some embodiments, as shown in Figures 20 and 21, the annular ring 33 includes an air guide section 331 and a first extension section 332. The air guide section 331 is cylindrical, with one axial end of the first extension section 332 connected to one axial end of the air guide section 331, and the other axial end of the first extension section 332 extending radially inward of the air guide ring 40 toward the air outlet 171. The radius of the other end of the first extension section 332 is smaller than the radius of the one end of the first extension section 332.

[0138] 21 , the air guide ring 40 includes a second extension section 41 that matches the shape of the first extension section 332 and is located radially outward of the first extension section 332. A gap A2 is formed between the second extension section 41 and the first extension section 332.

[0139] For example, the first extension section 332 and the second extension section 41 are coaxially arranged to ensure a uniform gap between them. The front end of the first extension section 332 and the front end of the second extension section 41 are coplanar, and the plane passing through the front ends of the first extension section 332 and the second extension section 41 is perpendicular to the axis of the axial flow fan 30, ensuring that the front end of the first extension section 332 radially aligns with the front end of the second extension section 41. This improves the aerodynamic efficiency of the axial flow fan 30 and reduces operating noise.

[0140] In some embodiments, a plane defined by the left-right and front-back directions of any air conditioner is defined as a first reference plane. The orthographic projections of the first extension section 332 and the second extension section 41 on the first reference plane coincide with each other. Thus, along the axial direction of the air guide ring 40 (i.e., the axial direction of the annular ring 33), the widths of the first extension section 332 and the second extension section 41 are equal.

[0141] In some embodiments, as shown in FIG. 21 , the width of the gap A2 between the second extending section 41 and the first extending section 332 is approximately 1% to 10% of the inner diameter of the air guiding section 331 .

[0142] For example, the width of the gap A2 is 1% to 3%, 3% to 6%, or 6% to 10% of the inner diameter of the air guide segment 331 .

[0143] In some embodiments, the thickness of the annular ring 33 is 0.4 to 0.6 times the width of the gap A2. For example, the thickness of the annular ring 33 is 0.4, 0.5 or 0.6 times the width of the gap A2.

[0144] In some embodiments, the radius of the second extension section 41 is equal to the width of the first extension section 332 and the second extension section 41 in the axial direction of the air guide ring 40 .

[0145] In the present application, an annular ring 33 is provided on the outer periphery of the rear end of the blade 32, and the front end of the annular ring 33 is extended into the air guide ring 40, and the radial clearance between the air guide ring 40 and the blade 32 and the annular ring 33 is set to be equal. In this way, the leakage loss of the blade tip outside the air guide ring 40 when there is no annular ring 33 in the prior art is reduced, the leakage loss caused by the bell mouth of the air guide ring 40 is reduced, the aerodynamic efficiency is improved and the noise is reduced.

[0146] 22 and 23 , the blade 32 further includes a second serration portion 3201 . The second serration portion 3201 is disposed at the first side edge 321 and extends along the first side edge 321 .

[0147] It can be understood that when the axial flow fan 30 rotates, the second serration portion 3201 is located on the forward side of the blade 32, so that the incoming flow can be broken up in advance, the impact caused by the incoming flow is reduced, and the energy of the eddy current is reduced, which is beneficial to improving the working efficiency of the axial flow fan.

[0148] 24 and 25 , the third side edge 323 of the blade 32 includes a first line segment 3231, a second line segment 3232, and a third line segment 3233 that are sequentially connected. The first line segment 3231 and the third line segment 3233 are arc-shaped line segments.

[0149] The first line segment 3231 is located on a side of the second line segment 3232 that is close to the first side edge 321, and the third line segment 3233 is located on a side of the second line segment 3232 that is close to the second side edge 322. The radius R3 of the first line segment 3231 is greater than the radius R4 of the third line segment 3233 (i.e., R3>R4). The second line segment 3232 transitions between the first line segment 3231 and the third line segment 3233.

[0150] That is to say, the blade 32 has an unequal radius. The radius of the portion of the blade 32 close to the first side edge is larger, and the radius of the portion close to the second side edge is smaller. In this way, the amount of gas leakage in the third side edge gap can be reduced when the axial flow fan rotates, and the noise generated by the blade wake vortex can be reduced.

[0151] In some embodiments, the radius R3 of the first line segment 3231 is any value between 300 mm and 310 mm, and the radius R4 of the third line segment 3233 is any value between 290 mm and 300 mm.

[0152] For example, the radius R3 of the first line segment 3231 is 300 mm, 305 mm, or 310 mm.

[0153] For example, the radius R4 of the third line segment 3233 is 290 mm, 295 mm, or 300 mm.

[0154] In some embodiments, as shown in Figure 25, the second line segment 3232 is a spline curve. For example, the spline curve of the second line segment 3232 is in the shape of a dolphin tail, which can reduce the resistance encountered by the blades during rotation and improve the working efficiency of the axial flow fan.

[0155] In some embodiments, the first line segment 3231 occupies 70% to 85% of the entire length of the third side edge 323 , and the third line segment 3233 occupies 10% to 20% of the entire length of the third side edge 323 .

[0156] For example, the first line segment 3231 occupies 70%, 73%, 76%, 78.85%, 81% or 85% of the entire length of the third side edge 323 , and the third line segment 3233 occupies 10%, 12.5%, 15.35%, 18% or 20% of the entire length of the third side edge 323 .

[0157] In some embodiments, as shown in FIG26 , the arc length between two points at the same blade height (i.e., the distances between these two points from the rotation axis of the center disk 31 are equal) on the first side edge 321 and the second side edge 322 of the blade 32 is denoted as P, and the straight-line distance is denoted as O. The elemental chord length of the blade 32 is denoted as S, where S is equal to the ratio of O to P (i.e., S = O / P). In FIG26 , the dashed straight line represents the straight-line distance O, and the bold arc line represents the arc length P. In the direction from the fourth side edge 324 to the third side edge 323, the elemental chord length S of the blade 32 first increases and then decreases.

[0158] For example, referring to FIG26 , the elementary chord length of the fourth side edge 324 is S1, the elementary chord length of 25% of the blade height is S2, the elementary chord length of 50% of the blade height is S3, the elementary chord length of 75% of the blade height is S4, and the elementary chord length of the third side edge 323 is S5. S1 is smaller than S2, and S2 is smaller than S3. S3 is greater than S4, and S4 is greater than S5.

[0159] In some embodiments, as shown in Figure 27, the center pan 31 further includes a first surface 310 and a second surface 320. The first surface 310 is the end surface of the center pan 31 facing away from the air outlet 171, that is, the first surface 310 is the windward side of the center pan 31. The second surface 320 is the side surface of the center pan in the circumferential direction.

[0160] In some embodiments, as shown in FIG27 , the mid-pan 31 further includes a third surface 330. The first surface 310 and the second surface 320 are transitionally connected via the third surface 330. One axial end of the third surface 330 is connected to the first surface 310, and the other axial end of the third surface 330 is connected to the second surface 320. This optimizes the air flow path, reduces the impact of airflow on the mid-pan, and thereby improves the operating efficiency of the axial flow fan.

[0161] The arrows in Figure 27 represent the direction of gas flow. It can be understood that part of the airflow flows from the inside of the shell 10 to the first surface 310, then flows along the connecting surface 320 located on the peripheral side of the first surface 310 to the second surface 320, and then along the second surface 320, passes through the air outlet 171, and flows to the outside of the shell 10.

[0162] In some embodiments, any plane passing through the axis of the center disk 31 is defined as the target plane, and the intersection line between the third surface 330 and the target plane includes two opposite arcs, and the angle of each arc is 90°.

[0163] In some embodiments, as shown in FIG. 28 , along the axial direction of the center disk 31 , the size of the third surface 330 is H1 , the size of the center disk 31 is H2 , and H1 < H2 .

[0164] In some embodiments, as shown in Figures 29 and 30, the annular ring 33 connects the third side edges 323 of the plurality of blades 32, and the air guide ring 40 is provided on the outer peripheral side of the annular ring 33, with a gap A2 between the air guide ring 40 and the annular ring 33.

[0165] For example, the first line segment 3231 of the third side edge 323 is connected to the inner wall of the annular ring 33 , and gaps are formed between the second line segment 3232 , the third line segment 3233 and the inner wall of the annular ring 33 .

[0166] In some embodiments, as shown in FIG31 , the axial flow fan 30 further includes a wind shield 500. The wind shield 500 is disposed in the gap A2 and is configured to block airflow from the high-pressure area of ​​the pressure side of the axial flow fan through the gap A2 to the low-pressure area of ​​the suction side of the axial flow fan, thereby effectively reducing leakage losses and further facilitating improved aerodynamic efficiency of the axial flow fan 30.

[0167] In some embodiments, as shown in Figures 31 to 33, the wind shield 500 includes a first protrusion 510. The first protrusion 510 is disposed radially outward of the annular ring 33 and extends along the circumference of the annular ring 33. The first protrusion 510 is configured to block the air flow path within the gap A2, thereby reducing air leakage losses.

[0168] In some embodiments, as shown in Figures 31 to 33, the wind shield 500 further includes a second protrusion 520. The second protrusion 520 is disposed radially inward of the air guide ring 40 and extends circumferentially along the air guide ring 40. The second protrusion 520 is configured to block air flow within the gap A2, thereby reducing air leakage losses.

[0169] In some embodiments, the first protrusion 510 and the second protrusion 520 are spaced apart along the axial direction of the air guide ring 40, so as to block the gap A2, thereby preventing the airflow from the high-pressure area of ​​the pressure surface of the blade 32 to the low-pressure area of ​​the suction surface, effectively reducing the airflow leakage loss and improving the aerodynamic efficiency of the axial flow fan.

[0170] In some embodiments, as shown in FIG32 , the wind shield 500 includes a plurality of first protrusions 510, which are spaced apart along the axial direction of the annular ring 33 and disposed on the outer circumference of the annular ring 33. It will be appreciated that the plurality of first protrusions 510 can block the air flow within the gap A2 multiple times, thereby further reducing air leakage losses and improving the operating efficiency of the axial flow fan.

[0171] In some embodiments, as shown in FIG32 , the wind shield 500 includes a plurality of second protrusions 520 , which are spaced apart along the axial direction of the air guide ring 40 and disposed on the inner wall surface of the air guide ring 40. It will be appreciated that the plurality of second protrusions 520 can block the air flow within the gap A2 multiple times, thereby further reducing air leakage losses and improving the operating efficiency of the axial flow fan.

[0172] In some embodiments, the number of the plurality of first protrusions 510 corresponds to the number of the plurality of second protrusions 520, and the plurality of first protrusions 510 and the plurality of second protrusions 520 are staggered along the axial direction of the air guide ring 40. In other words, any second protrusion 520 among the plurality of second protrusions 520 is disposed between two corresponding first protrusions 510. This forms multiple barriers within the gap A2 to prevent reverse airflow, thereby preventing airflow losses due to leakage.

[0173] In some embodiments, the wind shield 500 includes an even number of first protrusions 510 . For example, the wind shield 500 includes 2, 4, 6, or 8 first protrusions 510 .

[0174] In some embodiments, the wind shield 500 includes an odd number of second protrusions 520 . For example, the wind shield 500 includes 1, 3, 5, or 7 second protrusions 520 .

[0175] In some embodiments, as shown in FIG. 32 , the wind shield 500 includes two first protrusions 510 and one second protrusion 520 , and the second protrusion 520 is located between the two first protrusions 510 .

[0176] In some embodiments, the cross-sectional shape of the first protrusion 510 and the second protrusion 520 is square, rectangular, circular, or triangular, etc. For example, referring to FIG32 , the cross-sectional shape of the first protrusion 510 and the second protrusion 520 is rectangular, thereby increasing the contact area between the first protrusion 510 and the second protrusion 520 and the airflow, which is beneficial to the low-height blocking effect of the gap A2.

[0177] In some embodiments, as shown in FIG32 , the distance D1 between the end surface of the first protrusion 510 facing away from the annular ring 33 and the outer circumference of the annular ring 33 is 0.1 to 0.5 times the width of A2. For example, the distance D1 is 0.1, 0.2, 0.35, or 0.5 times the width of A2.

[0178] In some embodiments, as shown in FIG. 32 , the distance between the end surface of the second protrusion 520 facing away from the air guide ring 40 and the inner wall surface of the air guide ring 40 is D2 , and the distance D2 is equal to the distance D1 .

[0179] In some embodiments, the sum of the distance D2 and the distance D1 is equal to the width of the gap A2. In this way, the staggered first protrusions 510 and the second protrusions 520 can block the gap A2 between the annular ring 33 and the air guide ring 40, thereby having a better effect of blocking airflow.

[0180] In some embodiments, as shown in FIG32 , the windshield 500 further includes a first extension 530 . The first extension 530 is annular and coaxially arranged with the annular ring 33 . One end of the first extension 530 connects to the end of the annular ring 33 away from the air outlet 171 , and the other end of the first extension 530 extends radially outward from the annular ring 33 to avoid the inlet airflow of the axial flow fan. The first extension 530 is configured to block the gap A2 to prevent air leakage.

[0181] In some embodiments, as shown in Figures 32, 34 and 35, the air guide ring 40 includes a first air guide portion 410, the first air guide portion 410 is cylindrical, and the second protrusion 520 is provided on the inner wall surface of the first air guide portion 410.

[0182] 35 , the air guide ring 40 further includes a second air guide portion 420 . The second air guide portion 420 is cylindrical and coaxially disposed with the first air guide portion 410 . The inner diameter of the first air guide portion 410 is smaller than that of the second air guide portion 420 .

[0183] In some embodiments, as shown in FIG35 , the wind shield 500 further includes a second extension portion 540. The second extension portion 540 is annular. The radial inner side of the second extension portion 540 is connected to the end of 410 away from the air outlet 171, and the radial outer side of the second extension portion 540 is connected to the end of 420 close to the air outlet 171. That is, the second air guide portion 420 is connected to the air inlet side of the first air guide portion 410 through the second extension portion 540, that is, the second extension portion 540 extends from the air inlet side of the first air guide portion 410 to the radial outer side of the first air guide portion 410. The second extension portion 540 is configured to cooperate with the first extension portion 530 to block the gap A2, thereby further reducing the loss of airflow leakage and improving the working efficiency of the axial flow fan.

[0184] 32 , the second extension portion 540 is closer to the air outlet 171 than the first extension portion 530. That is, the second extension portion 540 is located downstream of the first extension portion 530 along the air inlet direction of the axial flow fan.

[0185] In some embodiments, as shown in FIG. 32 , along the axial direction of the air guide ring 40 , the first extension portion 530 and the second extension portion 540 are spaced apart from each other.

[0186] In some embodiments, as shown in FIG32 , any axial plane perpendicular to the air guide ring 40 is defined as a second reference plane, and the orthographic projection of the first extension portion 530 on the second reference plane at least partially overlaps with the orthographic projection of the second extension portion 540 on the second reference plane.

[0187] It is understandable that the first extension portion 530 cooperates with the second extension portion 540 to further block the airflow between the air guide ring 40 and the annular ring 33, thereby reducing airflow leakage losses and improving the working efficiency of the axial flow fan.

[0188] In some embodiments, as shown in FIG35 , the air guide ring 40 further includes a third air guide portion 430. The third air guide portion 430 is annular and connected to the second air guide portion 420. The third air guide portion 430 extends outwardly from the air guide ring 40. For example, the connection between the third air guide portion 430 and the second air guide portion 420 is rounded.

[0189] In some embodiments, as shown in Figure 34, the air guide ring 40 is roughly an outward-flaring trumpet-shaped structure, that is, the inner diameter of the end of the air guide ring 40 away from the air outlet 171 is larger than the inner diameter of the end of the air guide ring 40 close to the air outlet 171, thereby helping to guide the air.

[0190] In some embodiments, as shown in FIG33 , the annular ring 33 , the center disk 31 , and the plurality of blades 32 are constructed as an integral part, thereby facilitating the processing and production of the axial flow fan 30 and reducing costs. For example, the annular ring 33 , the center disk 31 , and the plurality of blades 32 are integrally molded by injection molding.

[0191] Those skilled in the art will understand that the scope of the present invention is not limited to the above specific embodiments, and that certain elements of the embodiments may be modified and replaced without departing from the spirit of the present application. The scope of the present application is limited by the appended claims.

Claims

1. An air conditioner, comprising: a housing defining an air outlet; an axial flow fan, corresponding to the air outlet and disposed in the housing; The axial flow fan is configured to drive air flow; The axial flow fan comprises: Mid-game; and At least one blade connected to the outer periphery of the middle disk, the blade comprising: first side edge; A second side edge; wherein, along the circumference of the middle disk, the first side edge and the second side edge are opposite side edges of the blade; A third side edge is an edge of the blade away from the middle plate; and The fourth side edge is an edge of the blade close to the middle plate; A straight line passing through any point on the circumferential cross section of the blade and perpendicular to the axis of the center disk is defined as a first straight line, a tangent line of any point on the circumferential cross section of the blade is defined as a second straight line, and an acute angle between the first straight line and the second straight line is defined as an angle β; Wherein, in the direction from the fourth side edge to the third side edge, the angle β on the first side edge first increases, then decreases, and then increases again.

2. The air conditioner according to claim 1, wherein: In the direction from the fourth side edge to the third side edge, the first side edge is firstly recessed in a direction away from the air outlet, and then protrudes in a direction close to the air outlet.

3. The air conditioner according to claim 1 or 2, wherein: In the direction from the fourth side edge to the third side edge, the angle β on the second side edge shows a decreasing trend.

4. The air conditioner according to any one of claims 1 to 3, wherein: In the direction from the second side edge to the first side edge, the angle β on the third side edge shows a decreasing trend.

5. The air conditioner according to any one of claims 1 to 4, wherein: The blade further includes a plurality of notches, which are arranged at intervals on the second side edge along an extension direction of the second side edge.

6. The air conditioner according to any one of claims 1 to 5, wherein: The middle plate includes: an outer ring portion, wherein the at least one blade is disposed on an outer peripheral surface of the outer ring portion; a support portion, disposed in the outer ring portion; and A plurality of openings are provided on a side of the outer ring portion facing the air outlet and are configured to reduce the weight of the axial flow fan.

7. The air conditioner according to claim 6, wherein: The middle plate further comprises a first enclosing portion and a second enclosing portion; any one of the plurality of openings is enclosed by the first enclosing portion and the second enclosing portion; Wherein, at least a portion of the first enclosing portion is parallel to the fourth side edge of the blade, and at least a portion of the second enclosing portion is parallel to the axis of the center disk.

8. The air conditioner according to any one of claims 1 to 7, wherein: The blade further includes a protrusion; the protrusion is arranged on a side surface of the blade away from the air outlet; the protrusion is arranged close to the first side edge and extends along the extension direction of the first side edge; Wherein, in the direction from the third side edge to the fourth side edge, the width and thickness of the protrusion increase.

9. The air conditioner according to any one of claims 1 to 8, wherein: The housing further defines an air inlet and an air outlet, wherein the air inlet is arranged opposite to the air outlet; The air conditioner also includes: Air guide ring; and An annular ring, the annular ring being coaxially arranged with the air guide ring; the annular ring being located on a side of the air guide ring close to the air inlet, and an end of the annular ring close to the air outlet being located radially inward of the air guide ring; Wherein, the first part of the blade close to the air outlet is located in the air guide ring, and the second part of the blade close to the air inlet is located in the annular ring; the blade is connected to the annular ring.

10. The air conditioner according to claim 9, wherein: Along the radial direction of the air guide ring, the width of the gap between the air guide ring and the first portion of the blade is substantially equal to the width of the gap between the air guide ring and the annular ring.

11. The air conditioner according to claim 9 or 10, wherein: The annular ring comprises: Air guide section; and a first extension section, wherein one axial end of the first extension section is connected to one axial end of the air guide section, and the other axial end of the first extension section extends to the radial inner side of the air guide ring in a direction close to the air outlet; Wherein, the radius of the other end of the first extension section is smaller than the radius of the one end of the first extension section.

12. The air conditioner according to claim 11, wherein: The air guide ring includes a second extension section, the second extension section matches the shape of the first extension section, and is located radially outside the first extension section.

13. The air conditioner according to claim 12, wherein: The other end of the first extension section is coplanar with one end of the second extension section close to the air outlet, and a plane passing through the other end of the first extension section and one end of the second extension section close to the air outlet is perpendicular to the axis of the middle disk.

14. An air conditioner, comprising: a housing defining an air outlet; an axial flow fan, corresponding to the air outlet and disposed in the housing; The axial flow fan is configured to drive air flow; The axial flow fan comprises: Mid-game; and At least one blade connected to the outer periphery of the middle disk, the blade comprising: first side edge; A second side edge; wherein, along the circumference of the middle disk, the first side edge and the second side edge are opposite side edges of the blade; a fourth side edge, which is an edge of one side of the blade close to the middle plate; and The third side edge is an edge of the blade away from the middle plate; wherein the portion of the blade close to the second side edge and the third side edge is warped in a direction away from the air outlet; A straight line passing through any point on the circumferential cross section of the blade and perpendicular to the axis of the center disk is defined as a first straight line, a tangent line of any point on the circumferential cross section of the blade is defined as a second straight line, and an acute angle between the first straight line and the second straight line is defined as an angle β; Wherein, in the direction from the fourth side edge to the third side edge, the angle β on the first side edge first increases, then decreases, and then increases again.

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