Axial flow fan, air conditioner outdoor unit and air conditioner

Abstract

The present disclosure relates to an axial flow fan blade, a fan assembly, an air conditioner outdoor unit and an air conditioner. The axial flow fan blade comprises a hub and a plurality of blades arranged on the outer side of the hub, each blade comprising a pressure surface and a suction surface arranged oppositely, each blade comprising a blade inner edge and a blade outer edge arranged oppositely, and each blade further comprising a blade leading edge and a blade trailing edge arranged oppositely. Each blade is divided into a first region, a second region and a third region in a circumferential direction. The first included angle of the first region, the second included angle of the second region and the third included angle of the third region are selected to be in a ratio of 1:1.25-1.9:1.25-1.9.

Description

Technical Field

[0001] This invention relates to the field of air conditioners. Specifically, it relates to axial fan blades, fan assemblies, outdoor units of air conditioners, and air conditioners. Background Technology

[0002] The fan system is the main component of an air conditioner's outdoor unit used for heat dissipation and air delivery. When the fan system is working, the motor drives the motor shaft to rotate, which in turn drives the fan impeller to rotate at high speed. The fan system converts the mechanical energy of the rotating shaft into the pressure energy and kinetic energy of the air, thereby accelerating heat dissipation. During this energy conversion process, mechanical losses, volumetric losses, and flow losses often occur. The efficiency of the fan system is usually measured by impeller efficiency (the ratio of the actual effective energy gained by the gas transported by the fan system per unit time to the impeller power). When an axial fan rotates at high speed, aerodynamic noise, consisting of rotational noise and eddy current noise, is the main noise source of the air conditioning system. The noise level of an air conditioning system is directly related to the consumer's experience with the product; low noise is a core competitive advantage for air conditioning products. Given the increasingly stringent national requirements for air conditioning system energy efficiency and consumers' growing demands for product noise reduction, the design of high-airflow, high-efficiency, and low-noise fan systems is of great significance.

[0003] The outdoor unit fan system of an air conditioner consists of a motor, motor bracket, axial fan blades, guide ring, and air outlet grille. The aerodynamic performance of the axial fan blades, guide ring, and air outlet grille directly affects the heat exchange efficiency of the fan system. Based on the idea of ​​optimizing aerodynamic noise, there is significant room for improvement in all three components.

[0004] In the existing technology, a three-bladed axial flow fan blade has been proposed. The three-bladed axial flow fan blade has a relatively high rotational speed for the same air volume, and its applicable range is narrower. Under ultra-high speed operation, its sound quality, air force and reliability are relatively risky.

[0005] In view of this, the present invention is proposed. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide an axial flow fan blade, fan assembly, outdoor heat exchanger and air conditioner that provides heat exchange efficiency and reduces noise.

[0007] To solve the above-mentioned technical problems, the first objective of this invention is to provide an axial flow fan blade, including a hub and a plurality of blades disposed on the circular outer wall of the hub. Each of the plurality of blades includes a pressure surface and a suction surface disposed opposite to each other. The pressure surface faces away from the motor connection end of the hub, and the suction surface faces the motor connection end of the hub. Each of the plurality of blades includes an inner edge and an outer edge disposed opposite to each other. The inner edge of the blade is located at the connection between the blade and the hub, and the outer edge of the blade is away from the hub. Each of the plurality of blades also includes a leading edge and a trailing edge disposed opposite to each other. The leading edge of the blade is located on the windward side of the blade, and the trailing edge of the blade is located on the leeward side of the blade. Each of the plurality of blades is divided into a first region, a second region, and a third region along the circumference of the hub; the first region has a first angle formed by a first set of straight lines, wherein the first straight line in the first set of straight lines is a straight line passing through the center of the hub and the intersection of the outer edge of the blade's pressure surface and the leading edge of the blade, and the second straight line in the first set of straight lines is a straight line passing through the center of the hub and the intersection of the leading edge of the blade's pressure surface and the hub; the second region has a second angle formed by a second set of straight lines, wherein the first straight line in the second set of straight lines is a straight line in the first set of straight lines. The second straight line, in the second group of straight lines, is a straight line passing through the center of the hub and the intersection of the outer edge of the blade and the trailing edge of the blade's pressure surface; the third region has a third included angle formed by the third group of straight lines, the first straight line in the third group of straight lines is the second straight line in the second group of straight lines, the second straight line in the third group of straight lines is a straight line passing through the center of the hub and the intersection of the trailing edge of the blade's pressure surface and the hub, and the size of the first included angle, the second included angle and the third included angle are selected to have a ratio of 1:1.25~1.9:1.25~1.9.

[0008] Further optionally, the sizes of the first included angle, the second included angle, and the third included angle are selected to have a ratio of 1:1.58:1.63.

[0009] Further optionally, the first included angle and the second included angle form the flange wrap angle of the wind turbine blade, and the second included angle and the third included angle form the hub wrap angle of the wind turbine blade, wherein the ratio of the flange wrap angle to the hub wrap angle is designed to be in the range of 0.7 to 1.0.

[0010] Further optionally, the ratio of the rim wrap angle to the hub wrap angle is designed to be 0.792.

[0011] Optionally, the pressure surface of the blade is provided with three regions in the axial direction. The first region of the three regions is defined by a first horizontal line passing through the highest point of the pressure surface of the blade and a second horizontal line passing through the intersection of the trailing edge of the pressure surface of the blade and the hub. The second region of the three regions is defined by a third horizontal line passing through the intersection of the leading edge of the pressure surface of the blade and the hub and a fourth horizontal line passing through the intersection of the leading edge of the pressure surface of the blade and the tip radius of the blade. The third region of the three regions is defined by a first horizontal line passing through the highest point of the pressure surface of the blade and a fourth horizontal line passing through the intersection of the leading edge of the pressure surface of the blade and the tip radius of the blade. The ratio of the distance between the first and second horizontal lines defining the first region to the distance between the first and fourth horizontal lines defining the third region is set to be in the range of -0.1 to 0.1, and the ratio of the distance between the third and fourth horizontal axes defining the second region to the distance between the first and fourth horizontal lines defining the third region is set to be in the range of 0.45 to 0.55.

[0012] Further optionally, the ratio of the distance between the first and second horizontal lines defining the first region to the distance between the first and fourth horizontal lines defining the third region is set to 0.04.

[0013] Further optionally, the ratio of the distance between the third and fourth horizontal axes defining the second region to the distance between the first and fourth horizontal lines defining the third region is set to 0.492.

[0014] Alternatively, the plurality of blades are equidistantly arranged on the circular outer wall of the hub.

[0015] Further optionally, the structure between the top end face of the hub of the fan blade and the top end face of the shaft hole for mounting the fan blade is configured as a trapezoidal groove, and the angle formed by the generatrix of the rotating surface of the groove and the axis of the shaft hole is in the range of 25° to 90°.

[0016] Alternatively, the angle between the generatrix of the rotating surface of the groove and the axis of the shaft hole is 29°.

[0017] Further optionally, an axisymmetric circular hole is provided on the bottom end face of the groove, the diameter of the circular hole being set in the range of 10mm to 15mm.

[0018] Alternatively, the diameter of the circular hole is set to 10 mm.

[0019] Further optionally, a rectangular groove is provided at the top of the shaft hole, the rectangular side length of which is set to be 1.2 to 2.0 times the diameter of the shaft hole of the fan blade.

[0020] Further optionally, the rectangular side length of the groove is set to be 1.6 times the diameter of the shaft hole of the fan blade.

[0021] Alternatively, the depth of the groove is set to be in the range of 2 mm to 4 mm.

[0022] Alternatively, the depth of the groove is set to 3.2 mm.

[0023] The present invention also proposes an outdoor unit for an air conditioner, the outdoor unit for an air conditioner including a housing, wherein the housing is provided with an axial flow fan blade as described in any one of the preceding claims.

[0024] Optionally, the housing has ventilation holes, the axial flow fan is located at the ventilation holes, and a grille structure is installed on the ventilation holes. The grille structure includes an inner peripheral support structure and an outer peripheral support structure. The outer peripheral support structure is disposed on the peripheral wall of the ventilation holes, and the inner peripheral support structure is disposed within the outer peripheral support structure. The grille structure includes radial ribs evenly distributed circumferentially. The radial ribs of the grille structure are formed by a streamlined cross-section swept along a feature line. The installation angle between the streamlined cross-section and the horizontal direction is set to be linearly distributed along the feature line direction.

[0025] Further optionally, the mounting angle of the starting point of the feature line is set to be in the range of 55° to 60°, and the linear angle increment along the feature line is set to be in the range of 10° to 15°.

[0026] Further optionally, the angle of the starting point of the feature line is set to 57.5°, and the linear angle increment along the feature line is set to 10°.

[0027] Further optionally, the bending direction of the radial ribs of the grille structure is consistent with the rotation direction of the blade, and the feature lines of the radial ribs are arranged in an "X" shape with the trailing edge of the blade.

[0028] Further optionally, the radial rib includes long ribs and short ribs, which are arranged alternately in the circumferential direction. The long rib includes a straight line segment, a first arc segment, and a second arc segment connected sequentially from the inner circumferential support structure to the outer circumferential support structure. The short rib includes the first arc segment and the second arc segment. The rib feature lines corresponding to the endpoints of the straight line segment, the first arc segment, and the second arc segment correspond to a first diameter, a second diameter, and a third diameter, respectively. The first diameter is set to be 0.2 to 0.4 times the third diameter, and the second diameter is set to be 0.5 to 0.8 times the third diameter.

[0029] Further optionally, the first diameter is set to be 0.26 times the third diameter, and the second diameter is set to be 0.642 times the third diameter.

[0030] Further optionally, the radius of the first arc segment and the radius of the second arc segment are both set to be 0.3 to 0.5 times the third diameter.

[0031] Further optionally, the radius of the first arc segment is set to be 0.4 times the third diameter.

[0032] Further optionally, the radius of the second arc segment is set to be 0.36 times the third diameter.

[0033] Further optionally, the streamlined cross-section of one of the long ribs and the short ribs is configured with a variable mounting angle distribution along the feature line direction, and the streamlined cross-section of the other of the long ribs and the short ribs is configured with a constant mounting angle distribution.

[0034] Further optionally, the diameter at the intersection of the feature line of the radial rib and the trailing edge of the blade is set to be 0.4 to 0.8 times the third diameter.

[0035] Further optionally, the diameter at the intersection of the feature line of the radial rib and the trailing edge of the blade is set to be 0.63 times the third diameter.

[0036] Further optionally, the grid structure includes a plurality of annular ribs concentrically arranged relative to the inner peripheral support structure, the plurality of annular ribs being arranged radially outward in the form of concentric circles, and the distance between two adjacent annular ribs being set in the range of 8.5 mm to 10 mm.

[0037] Further optionally, the distance between two adjacent annular ribs in the annular rib is set to 9.7 mm.

[0038] The present invention also proposes a fan assembly for use in the above-mentioned outdoor unit of the air conditioner, wherein the fan assembly is installed at the ventilation hole of the housing of the outdoor unit of the air conditioner.

[0039] Further optionally, the fan assembly includes a guide ring, the axial flow fan blade is located within the annular space formed by the guide ring, the distance between the highest point of the axial flow fan blade and the front panel plane of the fan assembly is represented by hf1, the distance between the highest point of the axial flow fan blade and the lowest point of the grille is represented by hf2, and the radius difference between the diameter of the axial flow fan blade and the minimum diameter of the guide ring is represented by hf3. Wherein, hf3 is set to be in the range of 8mm to 12mm, hf1 is set to be in the range of -10mm to 0mm, hf2 is set to be in the range of 10mm to 30mm, and hf1+hf2>=20mm.

[0040] Alternatively, the value of hf1 can be -3mm.

[0041] Alternatively, the value of hf2 is 18 mm.

[0042] The present invention also proposes an air conditioner, which includes the above-mentioned axial flow fan blades, or includes the above-mentioned outdoor air conditioning unit, or includes the above-mentioned fan assembly.

[0043] By adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art:

[0044] 1. The axial flow fan blade proposed in this invention improves the working efficiency of the fan blade, reduces power consumption, increases air volume, and improves noise by designing parameters such as the number of blades and the angle of different areas of the blades, so as to achieve a balance between air volume, noise and power, and provide a high-efficiency and low-noise axial flow fan blade.

[0045] 2. The air outlet grille proposed in this invention adopts radial ribs with a linear installation angle distribution and uses a variable installation angle to further optimize wind resistance and reduce power consumption.

[0046] 3. The optimized structural matching relationship between the guide ring, axial flow fan blades and air outlet grille proposed in this invention further reduces wind noise.

[0047] The specific embodiments of the present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0048] The accompanying drawings, as part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention, but do not constitute an undue limitation of the invention. Obviously, the drawings described below are merely some embodiments, and those skilled in the art can obtain other drawings based on these drawings without creative effort. In the drawings:

[0049] Figure 1 : This is a top view of the front of a four-bladed axial flow fan blade according to an embodiment of the present invention.

[0050] Figure 2 : This is a top view of the back of a four-bladed axial flow fan blade according to an embodiment of the present invention.

[0051] Figure 3 : This is a schematic diagram of the hub wrap angle of the wind turbine blade flange in an embodiment of the present invention.

[0052] Figure 4 : This is a schematic diagram of the circumferential partitioning of the wind turbine blades according to an embodiment of the present invention.

[0053] Figure 5 : This is a schematic diagram of the assembly state of the fan blades in an embodiment of the present invention.

[0054] Figure 6 : This is a schematic diagram of the fan blade axis surface in an embodiment of the present invention.

[0055] Figure 7 : This is a schematic diagram of the trapezoidal groove structure of the wind turbine hub according to an embodiment of the present invention.

[0056] Figure 8 : This is a schematic diagram of the water leakage hole structure in the center of the wheel hub according to an embodiment of the present invention.

[0057] Figure 9 : This is a schematic diagram of the rectangular groove structure at the top of the shaft hole according to an embodiment of the present invention.

[0058] Figure 10 : This is a schematic diagram of the grid structure according to an embodiment of the present invention.

[0059] Figure 11 : This is a schematic diagram of the spacing between the annular ribs in an embodiment of the present invention.

[0060] Figure 12 : This is a schematic diagram of the radial rib feature lines of the grille in an embodiment of the present invention.

[0061] Figure 13 This is a schematic diagram of the cross-section and mounting angle of the radial rib streamline of the grille according to an embodiment of the present invention.

[0062] Figure 14 : This is a schematic diagram showing the relative position of the radial rib feature line of the grille and the trailing edge of the blade.

[0063] Figure 15 : This is a schematic diagram of the structural relationship between the fan blade, guide ring, and grille.

[0064] Figure 16 This is a schematic diagram of the overall structure of the outdoor unit of the air conditioner according to an embodiment of the present invention.

[0065] Figure 17 : This is a noise comparison curve between the original fan system and the fan system of this embodiment under the same air volume.

[0066] Figure 18 : This is a power comparison curve between the original fan system and the fan system of this embodiment under the same air volume.

[0067] Wherein: 1-Four-bladed axial flow fan blade; 2-Guide ring; 3-Grate structure; 4-Shell; 5-Blade; 6-Hub; 7-Blade trailing edge; 8-Blade leading edge; 9-Blade inner edge; 10-Blade outer edge; 11-First end face; 12-Second end face; 13-Trapezoidal groove; 14-Axis axis; 15-Round hole; 16-Groove; 18-Inner peripheral support structure; 19-Outer peripheral support structure; 20-Annular rib; 21-Radial rib; 22-Rib feature line; 23-Motor; 24-Motor connection end; 25-Windward side; 26-Leisure side.

[0068] It should be noted that these accompanying drawings and textual descriptions are not intended to limit the scope of the invention in any way, but rather to illustrate the concept of the invention to those skilled in the art by referring to specific embodiments. Detailed Implementation

[0069] In the description of this invention, it should be noted that the terms "inner" and "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0070] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," "contact," and "communication" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0071] Example 1

[0072] This embodiment proposes an axial flow fan blade 1, which has multiple blades 5, preferably three or four blades. This application uses a four-bladed axial flow fan blade as an example to describe the axial flow fan blade 1. Figures 1-5 As shown, the four-bladed axial flow fan 1 includes a hub 6 and four blades 5 disposed on the outer side of the hub 6. The four blades 5 are evenly distributed on the outer side of the hub 6 at a certain installation angle, and the four blades 5 rotate within a circumference with the center of the hub 6 as the center and the length of the blade 5 as the radius. The blade 5 includes a first end face 11 and a second end face 12 facing away from each other. The first end face 11 faces away from the motor connection end 24 of the hub 6 (i.e., the end of the axial flow fan 1 where the hub 6 is connected to the motor 23), and the second end face 12 faces the motor connection end of the hub 6. The first end face 11 is the pressure surface of the blade 5, and the second end face 12 is the suction surface of the blade 5.

[0073] Four blades 5 are equidistantly arranged on the circular outer wall of the hub 6. Compared to a three-bladed fan, a four-bladed fan provides a significantly higher airflow at the same rotational speed, reducing the required airflow speed. This not only expands the upper limit of the casing's capacity but also reduces stress concentration during high-speed fan operation. A hub ratio that is too small will result in a lower fan pressure coefficient, while a hub ratio that is too large will lead to a smaller blade working area and a rapid increase in fan weight. In this embodiment, the preferred hub ratio range is between 0.28 and 0.32, and preferably, the hub ratio is 0.3.

[0074] The wrap angle of blade 5 at different cylindrical levels is generally positively correlated with the blade cascade density (blade cascade density = chord length / cascade pitch, where chord length refers to the maximum length of the blade profile along the line connecting the two endpoints of the blade's midline, and cascade pitch is the distance between two adjacent blade profiles in the cascade), which is closely related to the aerodynamic characteristics of the wind turbine. Furthermore, the blade rim side is generally the high-efficiency working area with higher pressure, while the hub side is the low-efficiency working area with lower pressure. To avoid significant lateral secondary flow on the blade, the pressure difference in the blade height direction needs to be reduced. Therefore, under the premise of meeting mold requirements and reasonable blade cascade density, the hub wrap angle is usually set to be greater than the rim wrap angle. However, an excessively large hub wrap angle will also cause a decrease in the wind turbine's efficiency. Preferably, as... Figure 3 As shown, on the horizontal projection plane, the wrap angle ratio α1:α2 of the wind turbine blade hub is designed to be in the range of 0.7 to 1.0. More preferably, the wrap angle ratio α1:α2 of the wind turbine blade hub is designed to be 0.792, thereby reducing the pressure difference in the blade height direction and avoiding the formation of significant lateral secondary flow on the blade.

[0075] Further optional, such as Figures 1 to 5As shown, the blade 5 includes an inner edge 9 and an outer edge 10 arranged opposite to each other. The inner edge 9 is located at the connection between the blade 5 and the hub 6, and the outer edge 10 is away from the hub 6. The blade 5 also includes a leading edge 8 and a trailing edge 7 arranged opposite to each other. The leading edge 8 is located on the windward side 25 of the blade 5, and the trailing edge 7 is located on the leeward side 26 of the blade 5.

[0076] like Figure 4 As shown, blade 5 is divided into three regions along the circumference: θ1 (composed of L1 and L2), θ2 (composed of L2 and L3), and θ3 (composed of L3 and L4). L1 is a straight line passing through the center of hub 6 and the intersection of the outer edge of the blade pressure surface 11 and the leading edge of the blade; L2 is a straight line passing through the center of hub 6 and the intersection of the leading edge of the blade pressure surface and the hub; L3 is a straight line passing through the center of hub 6 and the intersection of the outer edge of the blade pressure surface and the trailing edge of the blade; L4 is a straight line passing through the center of hub 6 and the intersection of the trailing edge of the blade pressure surface and the hub. θ1+θ2 essentially describes the blade rim wrap angle α1, and θ2+θ3 is the hub wrap angle α2 (as shown in the diagram). Figure 3 (As shown). Further, θ1 can be defined as the forward curve of the blade, θ2 as the middle part of the blade, and θ3 as the backward curve of the blade. When the blade rim wrap angle is constant, appropriately increasing the forward curve of θ1 can improve the working efficiency of the blade and reduce noise, while appropriately increasing the backward curve of θ2 can increase the air volume and reduce power consumption. Overall, there is a relatively reasonable optimal allocation ratio of θ1, θ2, and θ3 to achieve a balance between air volume, noise, and power. The preferred range of θ1:θ2:θ3 is 1:1.25~1.9:1.25~1.9, more preferably, the value of θ1:θ2:θ3 is 1:1.58:1.63, and even more preferably, the value of θ1:θ2:θ3 is 1:1.7:1.55, so that the air volume, noise, and power achieve the best balance.

[0077] like Figure 5As shown, the pressure surface of blade 5 has three regions along its axial direction, with two key control parameters: h1 (composed of k1 and k2) and h2 (composed of k3 and k4). k1 is a horizontal straight line passing through the highest point of the pressure surface of blade 5; k2 is a horizontal straight line passing through the intersection of the trailing edge of the pressure surface of blade 5 and the hub 6; k3 is a horizontal straight line passing through the intersection of the front edge of the pressure surface of blade 5 and the hub 6; and k4 is a horizontal straight line passing through the intersection of the front edge of the pressure surface of blade 5 and the blade tip radius. Further, h can be defined as the swept portion of blade 5, h2 as the forward swept portion of blade 5, and h1 as the backward swept portion of blade 5. Appropriately increasing the forward swept portion h2 can effectively increase airflow, but excessive h2 will result in insufficient blade tip strength. Maintaining the backward swept portion h1 within the range of -0.1 to 0.1 ensures a better match between the efficient working section of the blade and the guide ring. h2: The preferred range of h is 0.45 to 0.55, and the preferred value of the present invention is 0.492; h1: The preferred range of h is -0.1 to 0.1, and the preferred value of the present invention is 0.04.

[0078] Furthermore, such as Figure 7 As shown, the structure between the top end face of the hub 6 of the fan blade 1 and the top end face of the shaft hole for mounting the fan blade 1 is configured as a trapezoidal groove 13. The generatrix of the rotating surface of the groove 13 forms an angle β with the rotation axis 14 of the fan blade, which preferably ranges from 25° to 90°, and the preferred value in this invention is 29°. By configuring the hub 6 of the fan blade 1 as a groove structure of a trapezoidal rotating body and appropriately designing the slope of the rotating surface, when the fan blade 1 is used in a side-discharge outdoor unit, it can both prevent snow and meet the installation position design requirements due to the matching position of the fan blade 1 and the guide ring 2.

[0079] like Figure 8 As shown, an axisymmetric circular hole 15 is provided on the bottom end face of the trapezoidal groove 13. The number of circular holes is set to four or eight, and the diameter of the circular holes is preferably in the range of 10mm to 15mm. The preferred value of the present invention is 4×Φ10mm. The circular hole 15 at the bottom is a water leakage hole, mainly considering the water leakage requirement of the middle groove of the hub 6 when the fan blade 1 is used in the top-discharge outdoor unit.

[0080] like Figure 9 As shown, a rectangular groove 16 is provided at the top of the shaft hole of the fan blade 1. A C-shaped chamfer is provided on the lower side of the rectangular groove 16. The diameter of the shaft hole of the fan blade 1 is Φd. The preferred range of the rectangular side length b of the groove 16 is 1.2d to 2.0d, and the preferred range of the groove depth is 2mm to 4mm. In this invention, the preferred rectangular side length b is 1.6d, and the preferred depth is 3.2mm. This rectangular groove 16 is used to place a metal gasket to prevent excessive motor starting torque from causing cracking damage to the shaft hole of the fan blade 1.

[0081] Example 2

[0082] The second objective of this embodiment also proposes an outdoor unit for an air conditioner, such as... Figure 15 and Figure 16 As shown, the outdoor unit of the air conditioner in this embodiment includes an axial fan blade 1, a guide ring 2, a grille structure 3, and a housing 4. The axial fan blade 1 is mounted on a motor (not shown), and the motor bracket of the motor is connected and fixed to the housing 4. The guide ring 2 is installed inside the housing 4 and is coaxial with the axial fan blade 1. The grille structure 3 is installed outside the housing 4 and is coaxial with the axial fan blade 1.

[0083] Optionally, ventilation holes are provided on the housing 4, the axial flow fan blade 1 is located at the ventilation holes, and a grille structure 3 is installed on the ventilation holes. Figures 10 to 14 As shown, the grille structure 3 includes an inner peripheral support structure 18, an outer peripheral support structure 19, annular ribs 20, and radially distributed ribs 21. The outer peripheral support structure 18 is disposed on the peripheral wall of the ventilation hole, and the inner peripheral support structure 18 is disposed within the outer peripheral support structure 19. The area between the outer peripheral support structure 19 and the inner peripheral support structure 18 forms the air outlet area of ​​the grille structure. Preferably, the inner peripheral support structure 18 is circular, and the outer peripheral support structure 19 is square. The annular ribs 20 of the grille structure 3 are arranged radially outward in a concentric circle pattern.

[0084] like Figure 10 and Figure 11 As shown, the grille structure 3 includes multiple annular ribs 20, which are concentric with the inner circumferential support structure 18. The spacing between adjacent annular ribs 20 is dd, where dd needs to be determined according to actual needs. If the spacing between the annular ribs is too large, it will not meet the test requirements in the standard; if the spacing is too small, it will cause the grille's wind resistance to rise rapidly, leading to a significant decrease in the overall airflow and a deterioration in noise. To reduce wind resistance, while meeting safety regulations, the thickness of the annular ribs 20 needs to be as small as possible, and the spacing needs to be as large as possible. In this embodiment, as... Figure 11 As shown, the preferred range of the distance dd between any two adjacent annular ribs 20 is 8.5 mm to 10 mm, and the preferred value of the present invention is 9.7 mm.

[0085] like Figures 12-14 As shown, the grid structure 3 also includes multiple radial ribs 21, which are evenly arranged circumferentially along the inner circumferential support structure 18. Figure 13 As shown, the direction indicated by the arrow is the windward side. The radial rib 21 is formed by sweeping the streamlined body section along the feature line. The installation angle between the streamlined body section and the horizontal direction is Ψ, and Ψ is linearly distributed along the feature line direction. Figure 12 The streamlined cross-section of the radial rib 21 is shown. The cross-section adopts a blunt body shape at both ends, with the windward side being the larger end and the air outlet side being the smaller end, and the overall shape is streamlined. Figure 13The feature line 22 of the radial rib is shown. The radial rib is a 3D solid rib formed by sweeping a 2D streamlined cross-section along the feature line (path) (referring to the method of stacking a 2D cross-section along the feature line to form a 3D solid). The feature line is the movement path of the 2D cross-section. The preferred range of the feature line starting point Ψ angle is 55° to 60°, with a preferred value of 57.5° in this invention. The preferred range of the linear angle increment along the feature line is 10° to 15°, with a preferred value of 10° in this invention. The installation angle of the streamlined cross-section of the radial rib in the horizontal direction is a crucial control parameter in grille design. If this installation angle adopts a constant distribution along the rib feature line, the installation angle remains a fixed value when the streamlined cross-section sweeps along the feature line. The optimal installation angle is mostly located between 60° and 65°, at which point wind resistance optimization is essentially reached. By adopting a variable installation angle, not only can the wind resistance be further optimized and the power consumption reduced, but more importantly, the airflow can be better adhered to the flow by improving the airflow angle of attack at different radial positions (the airflow angle of attack refers to the difference between the streamline cross section at any position of the radial rib and the horizontal installation angle and the actual airflow angle at that position), thus reducing the wake area and further reducing aerodynamic noise.

[0086] like Figure 12 As shown, the radial ribs 21 of the grid structure 3 are divided into long ribs 23 and short ribs 24. The long rib 23 is composed of a straight line segment L, an arc segment R1, and an arc segment R2. The short rib 24 is formed by removing the straight line segment L from the long rib. The endpoints of the three rib feature lines correspond to diameters D1, D2, and D3, respectively. The preferred range for the diameter D1 corresponding to the rib feature line of the straight line segment L is [0.2, 0.4] * D3, and the preferred value in this invention is 0.26 * D3. The preferred range for the diameter D2 corresponding to the rib feature line of the arc segment R2 is [0.5, 0.8] * D3, and the preferred value in this invention is 0.642 * D3. The preferred range for the arc radius of the arc segment R1 and the arc radius of the arc segment R2 is [0.3, 0.5] * D3. More preferably, the preferred value for the arc radius of the arc segment R1 is 0.4 * D3, and the preferred value for the arc radius of the arc segment R2 is 0.36 * D3. The L-straight segment is mainly used to distinguish between long ribs 23 and short ribs 24. The design of short ribs 24 can reduce wind resistance in the central area of ​​the grille. The double-arc design of R1 and R2 can better control the curvature distribution of the radial rib feature lines and adapt to the airflow angle requirements at different radial positions.

[0087] As an alternative embodiment where the streamlined cross-sections of both long ribs 23 and short ribs 24 adopt variable mounting angles in the horizontal direction, in this grid structure, the streamlined cross-section of one of the long ribs 23 and short ribs 24 has a variable mounting angle distribution along the characteristic line direction, while the streamlined cross-section of the other of the long ribs 23 and short ribs 24 has a constant mounting angle distribution along the characteristic line direction. This ensures a relatively large airflow throughput at this location, which is beneficial for reducing wind resistance. This grid design, along with the variable mounting angle distribution of the long ribs 23 and short ribs 24 in this invention, achieves the same improvement effect.

[0088] like Figure 14 As shown, the bending direction of the radial ribs 21 of the grille structure 3 must be consistent with the rotation direction of the blade 1, and the rib feature lines 22 of the radial ribs and the trailing edge 8 of the blade are arranged in an "X" shape, with the preferred intersection point in the range of [0.4, 0.8] * D3. The preferred value in this invention is 0.63 * D3. This point is mainly to avoid the high-speed airflow from the trailing edge of the blade from simultaneously impacting the grille, forming phase resonance, amplifying noise, or unnecessary noise peaks. Specifically, if all airflows impact the grille simultaneously, it is equivalent to applying a large force (the resultant force of countless smaller forces) to the grille at the same moment, resulting in greater grille deformation, greater vibration, and thus greater noise. If the airflows do not impact the grille at the same time, it is equivalent to applying countless smaller forces to the grille at different moments, resulting in smaller grille deformation, less vibration, and naturally less noise.

[0089] Example 3

[0090] This embodiment also proposes a fan assembly, which includes the four-bladed axial flow fan 1 of Embodiment 1 and is installed in the outdoor unit of the air conditioner in Embodiment 2. The fan assembly is disposed within the housing 4 of the outdoor unit of the air conditioner in Embodiment 2. Figure 15As shown, the fan assembly in this embodiment also includes a guide ring 2, with the axial flow blade 1 located within the annular space formed by the guide ring 2. The distance between the highest point of the axial flow blade 1 and the front panel plane of the fan assembly is denoted by hf1; the distance between the highest point of the axial flow blade and the lowest point of the middle rib of the grille structure 3 is denoted by hf2; and the radius difference between the diameter of the axial flow blade 1 and the minimum diameter of the guide ring 2 is denoted by hf3. Specifically, when hf3 is set to be in the range of 8mm to 12mm, hf1 is set to be in the range of -10mm to 0mm, and hf2 is set to be in the range of 10mm to 30mm (preferably 18mm in this invention), and hf1 + hf2 >= 20mm. A smaller hf3 results in higher blade volumetric efficiency and less aerodynamic loss, but this is limited by process installation precision. Theoretically, hf1 = 0mm is relatively better, ensuring maximum matching between the blade's efficient working area and the guide ring. hf2 is the distance from the grille to the guide vane plane. First, considering safety regulations, hf1 + hf2 must be greater than or equal to 20mm. Second, the grille's position needs to match the outlet angle of the upstream axial fan blades, and there exists a relatively optimal solution. Overall, the system contains multiple components with different matching paths, and each parameter has a reasonable relatively optimal range. Satisfying the above-mentioned structural matching relationships between the fan blades, grille, and guide vane will further achieve optimal wind noise.

[0091] Example 4

[0092] This embodiment also proposes an air conditioner, which includes the axial flow fan blade 1 of Embodiment 1, or the outdoor unit of the air conditioner of Embodiment 2, or the fan assembly of Embodiment 3.

[0093] The combination scheme of fan blade 1, guide ring 2, and grille structure 3 in the outdoor unit of the air conditioner of this embodiment can obtain a fan system with significant aerodynamic performance advantages. The noise comparison curves of the original fan system and the fan system of this embodiment under the same air volume are shown in the figure. Figure 17 As shown, the power comparison curves of the original fan system and the fan system of this embodiment under the same air volume are as follows: Figure 18 As shown. In Figure 17 In the diagram, the horizontal axis represents the standard air volume, and the vertical axis represents the noise level. The upper curve is the noise curve of the original fan system, and the lower curve is the noise curve of the fan system in this embodiment. Figure 18 In the diagram, the horizontal axis represents the standard air volume, and the vertical axis represents the power. The upper curve is the power curve of the original fan system, and the lower curve is the power curve of the fan system in this embodiment.

[0094] from Figure 17 and Figure 18The comparison curves show that, under the same airflow conditions, the fan system of this embodiment reduces the motor input power by approximately 100W compared to the original fan system (when the motor power is 19000 m³ / h); under the same airflow conditions, the noise level of the fan system of this embodiment is reduced by 1-2 dB(A) compared to the original fan system. The data demonstrates that the fan system of this embodiment significantly improves the heat exchange efficiency of the air conditioner and reduces overall noise, effectively solving the problems of excessively high fan speed and high noise in the original fan system under high airflow demands.

[0095] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

[0096] It should be understood that terms such as “axial” and “radial” are used above with reference to the normal operating posture of the compressor. Furthermore, these terms have been used herein for explanatory purposes and should not be considered as additional limitations. The terms “generally,” “approximately,” and “substantially” are not unbounded terms and should be interpreted in accordance with the manner in which those skilled in the art interpret them.

[0097] Although the different examples have the specific components shown in the illustrations, the embodiments of this disclosure are not limited to these specific combinations. Some of the components or features in one example may be used in combination with features or components in another example.

[0098] Those skilled in the art will understand that the above embodiments are exemplary and not restrictive. That is, modifications of this disclosure will fall within the scope of the claims. Therefore, the following claims should be studied to determine their true scope and content.

Claims

1. An axial flow fan blade, comprising a hub and a plurality of blades disposed on the circular outer wall of the hub, each of the plurality of blades comprising a pressure surface and a suction surface facing away from each other, the pressure surface facing away from the motor connection end of the hub, and the suction surface facing towards the motor connection end of the hub; wherein, Each of the plurality of blades includes an inner edge and an outer edge disposed opposite to each other, the inner edge being close to the connection between the blade and the hub, and the outer edge being away from the hub; each of the plurality of blades also includes a leading edge and a trailing edge disposed opposite to each other, the leading edge being located on the windward side of the blade, and the trailing edge being located on the leeward side of the blade. The feature is that each of the plurality of blades is divided into a first region, a second region, and a third region along the circumferential direction of the hub; the first region has a first included angle formed by a first set of straight lines, wherein the first straight line in the first set of straight lines is a straight line passing through the center of the hub and the intersection of the outer edge of the blade's pressure surface and the leading edge of the blade, and the second straight line in the first set of straight lines is a straight line passing through the center of the hub and the intersection of the leading edge of the blade's pressure surface and the hub; the second region has a second included angle formed by a second set of straight lines, wherein the first straight line in the second set of straight lines is a straight line in the first set of straight lines. The second straight line in the second group of lines is a straight line passing through the center of the hub and the intersection of the outer edge of the blade and the trailing edge of the blade's pressure surface; the third region has a third included angle formed by the third group of lines, where the first straight line in the third group is the second straight line in the second group of lines, and the second straight line in the third group is a straight line passing through the center of the hub and the intersection of the trailing edge of the blade's pressure surface and the hub; the sizes of the first included angle, the second included angle, and the third included angle are chosen to have a ratio of 1:1.25~1.9:1.25~1.

9. The blade's pressure surface is provided with three regions in the axial direction. The first region is defined by a first horizontal line perpendicular to the axial direction of the axial flow fan blade, passing through the highest point of the pressure surface of the blade, and a second horizontal line perpendicular to the axial direction of the axial flow fan blade, passing through the intersection of the blade's trailing edge and the hub. The second region is defined by a third horizontal line perpendicular to the axial direction of the axial flow fan blade, passing through the intersection of the blade's leading edge and the hub, and a fourth horizontal line perpendicular to the axial direction of the axial flow fan blade, passing through the intersection of the blade's leading edge and the blade's tip radius. The third region is defined by a first horizontal line passing through the highest point of the pressure surface of the blade and a fourth horizontal line passing through the intersection of the blade's leading edge and the blade's tip radius. The ratio of the distance between the first and second horizontal lines defining the first region to the distance between the first and fourth horizontal lines defining the third region is set to be in the range of -0.1 to 0.1, and the ratio of the distance between the third and fourth horizontal lines defining the second region to the distance between the first and fourth horizontal lines defining the third region is set to be in the range of 0.45 to 0.

55.

2. The axial flow fan blade according to claim 1, characterized in that, The sizes of the first included angle, the second included angle, and the third included angle are chosen to be in a ratio of 1:1.58:1.

63.

3. The axial flow fan blade according to claim 1 or 2, characterized in that, The first included angle and the second included angle form the flange wrap angle of the wind turbine blade, and the second included angle and the third included angle form the hub wrap angle of the wind turbine blade. The ratio of the flange wrap angle to the hub wrap angle is designed to be in the range of 0.7 to 1.

0.

4. The axial flow fan blade according to claim 3, characterized in that, The ratio of the rim wrap angle to the hub wrap angle is designed to be 0.

792.

5. The axial flow fan blade according to claim 4, characterized in that, The ratio of the distance between the first and second horizontal lines defining the first region to the distance between the first and fourth horizontal lines defining the third region is set to 0.

04.

6. The axial flow fan blade according to claim 4, characterized in that, The ratio of the distance between the third and fourth horizontal axes defining the second region to the distance between the first and fourth horizontal lines defining the third region is set to 0.

492.

7. The axial flow fan blade according to claim 1, characterized in that, The plurality of blades are equidistantly arranged on the circular outer wall of the hub.

8. The axial flow fan blade according to claim 1 or 2, characterized in that, The structure between the top end face of the hub of the fan blade and the top end face of the shaft hole for mounting the fan blade is configured as a trapezoidal groove, and the angle formed by the generatrix of the rotating surface of the groove and the axis of the shaft hole is in the range of 25° to 90°.

9. The axial flow fan blade according to claim 8, characterized in that, The angle between the generatrix of the rotating surface of the groove and the axis of the shaft hole is 29°.

10. The axial flow fan blade according to claim 8, characterized in that, Multiple circular holes are provided on the bottom end face of the groove. The multiple circular holes are symmetrical with respect to the axis of the axial flow fan blade. The diameter of the circular holes is set in the range of 10mm to 15mm.

11. The axial flow fan blade according to claim 10, characterized in that, The diameter of the circular hole is set to 10 mm.

12. The axial flow fan blade according to claim 8, characterized in that, A rectangular groove is provided at the top of the shaft hole, and the rectangular side length of the rectangular groove is set to be 1.2 to 2.0 times the diameter of the shaft hole of the fan blade.

13. The axial flow fan blade according to claim 12, characterized in that, The rectangular side length of the rectangular groove is set to be 1.6 times the diameter of the shaft hole of the axial flow fan blade.

14. The axial flow fan blade according to claim 12, characterized in that, The depth of the rectangular groove is set to be in the range of 2mm to 4mm.

15. The axial flow fan blade according to claim 14, characterized in that, The depth of the rectangular groove is set to 3.2 mm.

16. An outdoor unit for an air conditioner, characterized in that, The outdoor unit of the air conditioner includes a housing, and the housing is provided with an axial flow fan blade as described in any one of claims 1-15.

17. The outdoor unit of an air conditioner according to claim 16, wherein a ventilation hole is provided on the housing, the axial flow fan is located at the ventilation hole, a grille structure is installed on the ventilation hole, the grille structure includes an inner peripheral support structure and an outer peripheral support structure, the outer peripheral support structure is disposed on the peripheral wall of the ventilation hole, and the inner peripheral support structure is disposed within the outer peripheral support structure, characterized in that, The grid structure includes radial ribs evenly distributed circumferentially. The radial ribs of the grid structure are formed by sweeping streamlined cross sections along feature lines. The streamlined cross sections and the horizontal mounting angle are linearly distributed along the feature line direction.

18. The outdoor unit of the air conditioner according to claim 17, characterized in that, The installation angle of the starting point of the feature line is set to be in the range of 55° to 60°, and the linear angle increment along the feature line is set to be in the range of 10° to 15°.

19. The outdoor unit of the air conditioner according to claim 18, characterized in that, The starting point of the feature line is set at an angle of 57.5°, and the linear angle increment along the feature line is set at 10°.

20. The outdoor unit of the air conditioner according to claim 17, characterized in that, The radial ribs of the grille structure bend in the same direction as the rotation direction of the blade, and the feature lines of the radial ribs are arranged in an "X" shape with the trailing edge of the blade.

21. The outdoor unit of an air conditioner according to any one of claims 17 to 20, characterized in that, The radial ribs include long ribs and short ribs, which are arranged alternately in the circumferential direction. The long ribs include a straight line segment, a first arc segment, and a second arc segment connected sequentially from the inner circumferential support structure to the outer circumferential support structure. The short ribs include the first arc segment and the second arc segment. The rib feature lines corresponding to the endpoints of the straight line segment, the first arc segment, and the second arc segment correspond to a first diameter, a second diameter, and a third diameter, respectively. The first diameter is set to be 0.2 to 0.4 times the third diameter, and the second diameter is set to be 0.5 to 0.8 times the third diameter.

22. The outdoor unit of the air conditioner according to claim 21, characterized in that, The first diameter is set to be 0.26 times the third diameter, and the second diameter is set to be 0.642 times the third diameter.

23. The outdoor unit of the air conditioner according to claim 21, characterized in that, The radius of the first arc segment and the radius of the second arc segment are both set to be 0.3 to 0.5 times the third diameter.

24. The outdoor unit of the air conditioner according to claim 23, characterized in that, The radius of the first arc segment is set to be 0.4 times the third diameter.

25. The outdoor unit of the air conditioner according to claim 23, characterized in that, The radius of the second arc segment is set to be 0.36 times the third diameter.

26. The outdoor unit of the air conditioner according to claim 21, characterized in that, The streamlined cross-sections of the long ribs and the short ribs are configured with variable mounting angles along the feature line direction.

27. The outdoor unit of an air conditioner according to any one of claims 17 to 20, characterized in that, The grid structure includes a plurality of annular ribs concentrically arranged relative to the inner peripheral support structure. The plurality of annular ribs are arranged radially outward in the form of concentric circles, and the distance between two adjacent annular ribs is set to be in the range of 8.5 mm to 10 mm.

28. The outdoor unit of the air conditioner according to claim 27, characterized in that, The distance between two adjacent annular ribs in the annular rib is set to 9.7 mm.

29. The outdoor unit of an air conditioner according to any one of claims 17 to 20, characterized in that, The outdoor unit of the air conditioner includes a fan assembly, which is installed at the ventilation hole of the casing of the outdoor unit. The fan assembly includes a guide ring and a front panel. The axial fan blade is located within the annular space formed by the guide ring. The front panel is located on the air outlet side of the fan assembly. The distance between the highest point of the axial fan blade and the plane of the front panel is denoted by hf1. The distance between the highest point of the axial fan blade and the lowest point of the grille structure is denoted by hf2. The difference between the diameter of the axial fan blade and the radius at the minimum diameter of the guide ring is denoted by hf3. Wherein, hf3 is set to be in the range of 8mm to 12mm, hf1 is set to be in the range of -10mm to 0mm, hf2 is set to be in the range of 10mm to 30mm, and hf1+hf2>=20mm.

30. The outdoor unit of the air conditioner according to claim 29, characterized in that, The value of hf1 is -3mm.

31. An air conditioner, characterized in that, It includes the axial flow fan blades as described in any one of claims 1-15, or the outdoor unit of an air conditioner as described in any one of claims 16-30.

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