Axial flow fan, axial flow fan and air conditioner

Abstract

The utility model discloses a kind of axial flow fan, axial flow fan and air conditioner, it is related to fan field. Axial flow fan includes hub and multiple blades. Each blade edge includes opposite root inner edge, blade tip outer edge, also includes opposite leading edge, trailing edge, root inner edge connects hub, leading edge is arc linearly forward swept to upstream air intake direction;Blade tip outer edge is projected on the first section plane perpendicular to the central axis of axial flow fan and includes first circular arc segment, one end of first circular arc segment is connected with trailing edge, the center of first circular arc segment is located on the central axis of axial flow fan, the diameter of first circular arc segment is D1;Second circular arc segment, one end of second circular arc segment is connected with leading edge, the center of second circular arc segment is located between the central axis of axial flow fan and the root inner edge of blade, the diameter of second circular arc segment is D2, and satisfy D2<D1. The blade of this axial flow fan can effectively improve tip flow condition, inhibit flow separation, reduce aerodynamic noise and improve the aerodynamic performance of axial flow fan.

Description

Technical Field

[0001] This utility model relates to the field of fan technology, specifically to an axial flow impeller, an axial flow fan, and an air conditioner. Background Technology

[0002] Axial flow fans are widely used in ventilation and cooling, air conditioning, industrial exhaust, and many other fields due to their large flow rate and compact structure. The aerodynamic performance and aerodynamic noise level of its core component, the impeller, directly determine the overall efficiency and quality of the machine.

[0003] As applications demand increasingly higher levels of efficiency, noise reduction, and compactness from wind turbines, traditional designs are gradually revealing some inherent flaws. For example, pursuing higher pressure and dimensionless flow rates typically requires increasing blade load or rotational speed, which can easily lead to flow separation in the blade tip region, generating significant eddies and secondary flow losses. This not only reduces wind turbine efficiency but is also a major source of aerodynamic noise. Furthermore, in space-constrained applications, wind turbines are required to provide sufficient airflow and pressure within smaller radial dimensions, making improvements to traditional impellers quite challenging.

[0004] Therefore, how to improve the above-mentioned shortcomings without increasing or even decreasing the radial dimension of the impeller is an urgent problem to be solved. Utility Model Content

[0005] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes an axial flow fan blade that can effectively improve the flow conditions at the blade tip, suppress flow separation, reduce aerodynamic noise, and improve the aerodynamic performance of the axial flow fan.

[0006] This utility model also aims to provide an axial flow fan and an air conditioner having the above-mentioned axial flow impeller.

[0007] According to an embodiment of the present utility model, an axial flow wind turbine includes a hub and a plurality of blades. The plurality of blades are spaced apart on the hub. Each blade has an edge including a corresponding inner edge at the blade root and an outer edge at the blade tip, as well as a corresponding leading edge and a trailing edge. The blade is connected to the hub at the inner edge at the blade root, and the leading edge sweeps forward in an arc shape in the upstream air intake direction. The projection of the outer edge of the blade tip onto a first cross-sectional plane perpendicular to the central axis of the axial flow wind turbine includes: The first arc segment has one end connected to the tail edge, the center of the first arc segment is located on the central axis of the axial flow wind turbine, and the diameter of the first arc segment is D1. The second arc segment has one end connected to the leading edge. The center of the second arc segment is located between the central axis of the axial flow impeller and the inner edge of the blade root. The diameter of the second arc segment is D2, and satisfies D2 <D1。

[0008] According to the axial flow wind turbine of this utility model embodiment, by cutting the blade tip portion near the leading edge with a circular arc of a specific diameter, the rotational linear velocity of the critical leading edge region is effectively reduced, thereby weakening the intensity of tip leakage flow and the size of leakage vortices at the source. In other words, the blade tip portion at the leading edge is the first to tangentially contact the airflow; that is, the airflow is first cut into by the smaller-diameter second circular arc segment, and then by the larger-diameter first circular arc segment. The reduced linear velocity of the second circular arc segment results in a relatively smaller size and intensity of the generated leakage vortex. Simultaneously, the leakage vortex generated by the second circular arc segment is further cut into by the subsequent, even larger-diameter first circular arc segment, further reducing the size and weakening the intensity of the leakage vortex. Thus, leakage losses and noise caused by tip leakage vortices can be significantly reduced.

[0009] The above design changes the chord length and aspect ratio of the blade tip region, redistributes the aerodynamic load at the blade tip, avoids the load being too concentrated at the leading edge, makes the load distribution more uniform, and delays flow separation.

[0010] Moreover, the inward-curving blade tip shape better conforms to the natural flow direction of airflow, reducing impact loss at the leading edge and improving air intake conditions.

[0011] By designing blades with unequal diameters, the flow at the blade tip can be effectively improved, flow separation suppressed, aerodynamic noise reduced, and the aerodynamic performance of the fan enhanced without increasing or even decreasing the radial dimension of the axial flow impeller. This design is more adaptable to space-constrained applications, meeting the fan's need to provide sufficient airflow and pressure within a smaller radial dimension.

[0012] In some embodiments, on the first cross-sectional plane, the straight line passing through the midpoint of the angle of the outer edge of the blade tip and the central axis of the axial flow wind turbine is the X-axis, and the straight line perpendicular to the X-axis and passing through the central axis of the axial flow wind turbine is the Y-axis; The distance between the center of the second arc segment and the Y-axis is a, and the distance between the center and the X-axis is b, and the following conditions are met: a is in the range of 0.01 to 0.06 times D1, and b is in the range of 0.01 to 0.07 times D1.

[0013] In some embodiments, the forward sweep angle θ of the blade satisfies: 25°≤θ≤45°.

[0014] In some embodiments, the forward sweep angle θ of the blade satisfies: 35°≤θ≤40°.

[0015] In some embodiments, the forward bending angle γ of the blade satisfies: 25°≤γ≤45°.

[0016] In some embodiments, the forward bending angle γ of the blade satisfies: 35°≤γ≤40°.

[0017] In some embodiments, the leading edge inlet installation angle β1 of the blade is 10°~25°, and the outlet installation angle β2 is 24°~50°.

[0018] In some embodiments, the axial flow impeller further includes reinforcing ribs connected to the hub and the inner edge of the blade root.

[0019] The axial flow fan of this utility model embodiment includes: an axial flow impeller as described in any of the above embodiments; and a motor connected to the impeller hub.

[0020] The air conditioner of this utility model embodiment includes the axial flow fan described in the above embodiment.

[0021] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0022] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a top view of an axial flow fan according to an embodiment of this application; Figure 2 This is an isometric view of an axial flow fan according to an embodiment of this application; Figure 3 This is a schematic diagram showing the positions of the pressure surface and suction surface of the axial flow fan in an embodiment of this application; Figure 4 This is a schematic projection of the axial flow wind turbine blades in the first cross-sectional plane according to an embodiment of this application; Figure 5 A cross-sectional view of an axial flow fan rotor in the Z-axis plane for some embodiments; Figure 6 This is a schematic projection of the blades in some embodiments onto the first cross-sectional plane; Figure 7 A cross-sectional view of the blades in the Z-axis plane for some embodiments; Figure 8 Schematic diagrams of axial flow fans in some embodiments; Figure 9 This is a schematic diagram of an air conditioner according to some embodiments.

[0023] Figure label: Axial flow fan 10, central axis L1, first cross-sectional plane S1 Wheel hub 1 Leaf blade 2, inner edge of leaf base 21, outer edge of leaf apex 22, midpoint of angle T1, leaf tip point of leading edge T2, leaf tip point of trailing edge T3 First arc segment 221, center Q1 of the first arc segment The second arc segment 222, the center of the second arc segment Q2, Leading edge 23, trailing edge 24, tangent at the leading edge P0P1, tangent at the trailing edge P3P2, leaf chord P0P3. Reinforcing rib 3 Pressure surface 5, suction surface 6 Axial flow fan 20, motor 21, air conditioner 30. Detailed Implementation

[0024] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0025] In the description of this utility model, it should be understood that the terms "center," "inner," "outer," "radial," "circumferential," "longitudinal," "lateral," "vertical," "horizontal," "clockwise," and "counterclockwise," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model 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, and therefore should not be construed as a limitation of this utility model. Furthermore, features defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more. In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0026] The following is for reference. Figures 1-7 The axial flow fan 10 according to an embodiment of the present invention is described. The axial flow fan 10 is a ventilation component that uses rotating blades 2 to drive air in a straight line. The axial flow fan 10 is characterized by large air volume, low air pressure, and simple and compact structure.

[0027] According to the axial flow impeller 10 of this utility model embodiment, refer to Figures 1-2It includes a hub 1 and multiple blades 2, with the multiple blades 2 spaced apart on the hub 1.

[0028] Each blade 2 is generally an irregular quadrilateral with four edges. The edges of each blade 2 include the inner edge 21 at the blade root and the outer edge 22 at the blade tip, as well as the leading edge 23 and the trailing edge 24. The blade 2 is connected to the hub 1 at the inner edge 21 at the blade root, and the leading edge 23 sweeps forward in an arc shape in the upstream air intake direction.

[0029] The inner edge 21 of the blade root 2 is mentioned here because it describes the part of the blade 2 that connects to the hub 1 as the inner edge 21 of the blade root. For example... Figures 1-3 As shown, the hub 1 is the central support component of the axial flow wind turbine 10, and the central axis of the hub 1 coincides with the central axis L1 of the axial flow wind turbine 10. Optionally, multiple blades 2 are equidistantly arranged on the outer periphery of the hub 1.

[0030] The blade 2 can be machined and connected to the hub 1 separately, for example by welding. Alternatively, the blade 2 can be integrally formed on the hub 1.

[0031] It should be noted that when the axial flow impeller 10 is working, the airflow enters from the leading edge 23 and exits from the trailing edge 24. Simply put, the airflow first contacts the blade 2 at the leading edge 23, and the airflow last exits the blade 2 at the trailing edge 24. The inlet direction refers to the direction of airflow coming from, and the outlet direction refers to the direction of airflow going out.

[0032] The outer edge 22 of the blade tip refers to the boundary region of blade 2 furthest from hub 1 in the radial direction. Blade 2 also includes a pressure surface 5 and a suction surface 6. Pressure surface 5 is the side of blade 2 facing the exhaust direction and has higher pressure. Suction surface 6 is the side of blade 2 facing the intake direction and has lower pressure. Taking the surface where blade 2 is located as the reference surface, the area of ​​blade 2 facing the intake direction is the upstream, and the area of ​​blade 2 facing the exhaust direction is the downstream.

[0033] Here, the leading edge 23 sweeps forward in an arc shape towards the upstream air intake direction. This means that the leading edge 23 is arc-shaped, and the tip portion where the leading edge 23 connects to the outer edge 22 of the blade tip is more upstream than the root portion where the leading edge 23 connects to the inner edge 21 of the blade root. In this way, the leading edge 23 becomes scimitar-shaped, allowing the blade tip to contact the airflow first and pressurize it, making the blade tip pressure higher than the blade root pressure. This helps to establish radial pressure balance, weaken the shock wave intensity in the channel, and reduce shock wave loss.

[0034] Traditional axial flow wind turbines typically employ a constant diameter design, meaning the outer edges of all blade tips lie on the same cylindrical surface, and the blades are either strung or simply twisted from root to tip. In pursuit of higher pressures and dimensionless flow rates, it is usually necessary to increase the blade load or rotational speed. This easily leads to flow separation in the blade tip region, generating significant eddy currents and secondary flow losses. This not only reduces turbine efficiency but is also a major source of aerodynamic noise (especially rotational noise and eddy current noise).

[0035] Specifically, strong tip leakage vortices exist at the tip clearance of impellers with equal diameters. These vortices not only cause significant energy loss and reduce efficiency, but also interact with subsequent blades to generate strong broadband noise, becoming a major component of the overall aerodynamic noise. Under high load conditions, the adverse pressure gradient on the blade suction surface easily causes flow separation to begin at the blade tip region. Once separation occurs, the fan performance deteriorates sharply, with a significant decrease in efficiency and pressure, an earlier surge boundary, and a narrower operating range.

[0036] Traditional designs often employ larger impeller diameters or higher rotational speeds to improve performance. However, increasing the impeller diameter contradicts the trend towards miniaturization and compactness in equipment. Conversely, using higher impeller rotational speeds introduces greater noise and presents structural strength challenges.

[0037] To address the aforementioned technical issues, this application proposes an innovative design in which the axial flow impeller 10 adopts a non-uniform diameter design.

[0038] Specifically, such as Figure 4 As shown, the projection of the outer edge 22 of the blade tip onto the first cross-sectional plane S1 perpendicular to the central axis L1 of the axial flow impeller 10 includes: The first arc segment 221 has one end connected to the tail edge 24. The center Q1 of the first arc segment 221 is located on the central axis L1 of the axial flow impeller 10. The diameter of the first arc segment 221 is D1.

[0039] The second arc segment 222 has one end connected to the leading edge 23. The center Q2 of the second arc segment 222 is located between the central axis L1 of the axial flow wind turbine 10 and the inner edge 21 of the blade root of the blade 2. The diameter of the second arc segment 222 is D2, and satisfies D2 <D1。

[0040] In other words, the outer edge 22 of the blade tip 2 is formed by connecting at least two arcuate edges in sequence, and the at least two arcuate edges are located on at least two cylindrical surfaces. Here, the projection of the outer edge 22 of the blade tip onto the first cross-sectional plane S1 may include only two arcuate segments, namely the first arcuate segment 221 and the second arcuate segment 222. The projection of the outer edge 22 of the blade tip onto the first cross-sectional plane S1 may also include more arcuate segments, with the additional arcuate segments connecting between the first arcuate segment 221 and the second arcuate segment 222. When there are more arcuate segments, such as a third arcuate segment (not shown in the figure), the third arcuate segment can be smoothly connected between the first arcuate segment 221 and the second arcuate segment 222. For the sake of simplicity, the following description will use the example of the projection of the outer edge 22 of the blade tip onto the first cross-sectional plane S1 including only the first arcuate segment 221 and the second arcuate segment 222.

[0041] The center Q1 of the first arc segment 221 is located on the central axis L1 of the axial flow wind turbine 10. The first arc segment 221, equivalent to the outer edge 22 of the blade tip, retains the outer edge structural features of a traditional axial flow blade. The diameter D2 of the first arc segment 221 is smaller than the diameter D1 of the first arc segment 221. This is equivalent to the tip of blade 2 near the leading edge 23 being cut by an arc of a specific radius (half of D2), such that the diameter of the leading edge 23 at the tip point T2 (D2) is smaller than the diameter of the trailing edge 24 at the tip point T3 (D1), thus forming a unique tip profile that converges towards the leading edge 23. The tip point T2 of the leading edge 23 is the point of maximum distance between the leading edge 23 and the hub 1, and it is also the intersection of the leading edge 23 and the outer edge 22 of the blade tip. The tip point T3 of the trailing edge 24 is the point of maximum distance between the trailing edge 24 and the hub 1, and it is also the intersection of the trailing edge 24 and the outer edge 22 of the blade tip.

[0042] Specifically, by cutting the tip portion of blade 2 near the leading edge 23 with an arc of a specific diameter (D2), the rotational linear velocity of the critical region of the leading edge 23 is effectively reduced, thereby weakening the intensity of the tip leakage flow and the size of the leakage vortex at its source. In other words, the tip portion of the leading edge 23 is the first to tangentially cut into the airflow; that is, the airflow is first cut into by the smaller diameter second arc segment 222, and then by the larger diameter first arc segment 221. The linear velocity of the second arc segment 222 is relatively smaller than that of the original diameter D1, resulting in a relatively smaller size and intensity of the leakage vortex. Simultaneously, the leakage vortex generated by the second arc segment 222 is cut into by the subsequent, even larger diameter first arc segment 221, further reducing the size and weakening the intensity of the leakage vortex. Thus, leakage losses and noise caused by tip leakage vortices can be significantly reduced.

[0043] In addition, cutting the tip of blade 2 near the leading edge 23 with an arc of a specific diameter (D2) also changes the chord length and aspect ratio of the tip region, redistributes the aerodynamic load at the blade tip, avoids the load being too concentrated at the leading edge 23, makes the load distribution more uniform, and delays flow separation.

[0044] Moreover, the inward-curving shape of the leading edge 23 of blade 2 is more in line with the natural flow direction of airflow, reducing the impact loss at the leading edge 23 and improving the intake conditions.

[0045] By designing blades 2 with unequal diameters, the flow at the blade tip can be effectively improved, flow separation suppressed, aerodynamic noise reduced, and the aerodynamic performance of the fan enhanced without increasing or even decreasing the radial dimension of the axial flow impeller 10. This design is more adaptable to space-constrained applications, meeting the fan's need to provide sufficient airflow and pressure within a smaller radial dimension.

[0046] In some embodiments, refer to Figure 4 On the first cross-section plane S1, the straight line passing through the midpoint T1 of the angle of the outer edge 22 of the blade tip and the center line of the axial flow impeller 10 is the X-axis, and the straight line perpendicular to the X-axis and passing through the center line of the axial flow impeller 10 is the Y-axis. The distance between the center Q2 of the second arc segment 222 and the Y-axis is a, and the distance between the center Q2 and the X-axis is b, and the following conditions are met: the range of a is 0.01 to 0.06 times D1, and the range of b is 0.01 to 0.07 times D1.

[0047] Specifically, the central angle formed by the blade tip T2 and the midpoint of the angle T1 of the leading edge 23 to the center of the hub 1 is equal to the central angle formed by the blade tip T3 and the midpoint of the angle T1 of the trailing edge 24 to the center of the hub 1.

[0048] Within the first section plane S1 of blade 2, the position of the center Q2 of the second circular arc segment 222 in the coordinate system is determined by the perpendicular distances of Q2 to the X-axis and Y-axis. The perpendicular distance from the center Q2 to the X-axis is a, which is the x-coordinate. The perpendicular distance from the center Q2 of the second circular arc segment 222 to the Y-axis is b, which is the y-coordinate of the center Q2 of the second circular arc segment 222. Therefore, the coordinates of the center Q2 on the first section plane S1 are (a, b).

[0049] The diameter D1 of the first arc segment 221 is taken as the reference dimension, where value a is 0.01 to 0.06 times the reference dimension (i.e., 0.01D1≤a≤0.06D1); value b is 0.01 to 0.07 times the reference dimension (i.e., 0.01D1≤b≤0.06D1). This ensures that the center Q2 of the second arc segment 222 is located within a reasonable area between the central axis L1 of the axial flow impeller 10 and the inner edge 21 of the blade root of the blade 2, thereby ensuring a smooth transition between the second arc segment 222 and the first arc segment 221, while optimizing the airflow inlet angle and flow adhesion characteristics in the blade tip region. Values ​​a and b together determine the spatial position of the second arc segment 222, thereby controlling the overall aerodynamic profile of the outer edge 22 of the blade tip, achieving uniform airflow introduction and reducing airflow loss.

[0050] Specifically, when the position of blade 2 is as follows Figure 4 As shown, when stationary, the positions of the first arc segment 221 and the second arc segment 222 ensure a smooth transition of airflow. However, when the blade 2 moves, the diameter D2 of the second arc segment 222 needs adjustment. Without adjusting the diameters D2 and D1 of the second and first arc segments 222, the airflow will become discontinuous at the junction of the two arc segments, causing a sudden change in airflow velocity. The originally stable airflow may form turbulent regions between the second and first arc segments 222 and pressure may also change abruptly. Adjusting the diameters D1 and D2 of the first and second arc segments 222, and the relationship between their center distances a and b, ensures good connectivity between the two arc segments. This allows the airflow to flow smoothly over the surface of the blade 2, reducing airflow separation, suppressing the generation of tip leakage vortices, further reducing flow losses, and improving airflow efficiency.

[0051] In some embodiments, refer to Figure 5 The forward sweep angle θ of blade 2 satisfies: 25°≤θ≤45°. Optionally, θ can be 25°, 28°, 30°, 35°, 38°, 40°, 45°, etc.

[0052] The forward sweep angle θ of blade 2 refers to the angle formed when the leading edge 23 of blade 2 is inclined relative to the direction of the incoming flow (X-axis) towards the forward direction of blade 2 as it extends from hub 1 toward blade tip. It is mainly used to describe the degree of inclination of the leading edge 23 of blade 2 relative to the incoming flow.

[0053] When the airflow flows towards blade 2 at a certain speed and direction, the airflow smoothly adheres to the surface of blade 2. Compared to a design without a sweep angle, the forward sweep angle θ guides the airflow to transition to the pressure surface 5 and suction surface 6 earlier along the arcuate surface of the leading edge 23 of blade 2. This reduces the tendency of the airflow to separate at the leading edge 23 of blade 2, avoiding flow turbulence and energy loss caused by airflow impact or sudden turning, thereby improving the adhesion flow characteristics of the airflow. In the blade tip region, the forward sweep angle θ, by adjusting the tilt direction of the leading edge 23 of blade 2, changes the airflow path and pressure distribution at the gap between the blade tip and the casing of the axial flow fan 20. This reduces the driving pressure difference for leakage of high-pressure side airflow to low-pressure side, while suppressing the formation of strong rotating vortices (i.e., blade tip leakage vortices) in the leaking airflow. This reduces energy loss, flow separation, and local vortex interference caused by blade tip leakage, thereby reducing flow loss and noise.

[0054] Among them, the preferred sweep angle θ of blade 2 satisfies: 35°≤θ≤40°.

[0055] In some embodiments, refer to Figure 6 The forward bending angle γ of blade 2 satisfies: 25°≤γ≤45°.

[0056] like Figure 2 and Figure 6 As shown, when the leading edge 23 of blade 2 extends from hub 1 to blade tip, it tilts backward in the direction of rotation (i.e., in the opposite direction to the direction of forward rotation), thus forming a backward angle with the inner edge 21 of blade root 2. This angle is called the forward bend angle γ.

[0057] The initial contact angle between the leading edge 23 of blade 2 and the airflow, and the forward bend angle γ, guide the airflow to flow more smoothly along the surface of blade 2, reducing the tendency of airflow separation at the leading edge 23 of blade 2, optimizing the airflow adhesion characteristics and boundary layer development on the surface of blade 2, and making the airflow more stable. At the same time, the forward bend angle γ adjusts the load distribution on the surface of blade 2, reduces local stress concentration, and improves the structural reliability of blade 2. In the tip region, the forward bend angle γ may reduce airflow separation and local eddies by optimizing the geometry of the leading edge 23, thus improving the tip flow characteristics.

[0058] Preferably, the forward bending angle γ of blade 2 satisfies: 35°≤γ≤40°. Optionally, γ can be 35°, 36°, 38°, 40°, etc.

[0059] In some embodiments, refer to Figure 7 The inlet installation angle β1 of the leading edge 23 of the blade 2 is 10°~25°, and the outlet installation angle β2 is 24°~50°.

[0060] Figure 7 This is a cross-sectional view of the leaf blade with two leaflets. The leaf chord P0P3 is the line connecting the leading edge 23 to the trailing edge 24.

[0061] The inlet mounting angle β1 is the angle between the tangent P0P1 at the leading edge 23 (a specific position near the leading edge 23) of blade 2 at the inlet and the blade chord P0P3. The outlet mounting angle β2 is the angle between the tangent P3P2 at the trailing edge 24 (a specific position near the trailing edge 24) of blade 2 at the outlet and the blade chord P0P3.

[0062] The inlet installation angle β1 determines the degree of matching between the angle at which the airflow enters blade 2 and the direction of airflow, affecting the adhesion flow state, load distribution, and initial energy transfer efficiency of the airflow in the inlet region of blade 2. Within a reasonable range, it can reduce flow separation and impact losses and optimize the stability of the inlet flow. The outlet installation angle β2 determines the direction of airflow when it leaves blade 2, controlling the final acceleration, pressure increase, and energy conversion effect of the airflow, ensuring smooth airflow discharge and efficient carrying of the kinetic and pressure energy given by blade 2. Together, they regulate the complete flow process of the airflow in the blade 2 channel, comprehensively affecting the aerodynamic performance, energy transfer efficiency, and flow losses of blade 2. With an inlet installation angle β1 = 10°~25° and an outlet installation angle β2 = 24°~50°, the inlet installation angle balances the smooth adhesion of the airflow at the inlet and the efficient discharge at the outlet, achieving the optimal balance between the aerodynamic efficiency, reasonable load distribution, and overall performance of blade 2.

[0063] In some embodiments, refer to Figures 1-2 The axial flow impeller 10 also includes a reinforcing rib 3, which is connected to the inner edge 21 of the blade root of the hub 1 and the blade 2.

[0064] During the rotation of the axial flow impeller 10, the blades 2 may bend downward or outward due to aerodynamic loads or centrifugal forces, causing the blades 2 to collide with adjacent components (such as the casing). Setting a reinforcing rib 3 at the inner edge 21 of the blade root can ensure that the blades 2 have sufficient bending strength during rotation, reduce the deflection of the blades 2 under aerodynamic loads, maintain the aerodynamic stability of the blades 2, and also improve the torsional stiffness of the connection area between the inner edge 21 of the blade root and the hub 1, preventing the blades 2 from rotating and deviating due to torque.

[0065] The axial flow fan 20 of this utility model embodiment, refer to... Figure 8 The axial flow fan 10 and motor 21 are included in any of the above embodiments. The motor 21 is connected to the hub 1, and the output shaft of the motor 21 is connected to the hub 1 to drive the axial flow fan 20 to rotate.

[0066] The air conditioner 30 of this utility model embodiment, referred to... Figure 9 This includes the axial flow fan 20 described in the above embodiments.

[0067] In this specification, the terms "embodiment," "example," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0068] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. An axial flow impeller, characterized in that, It includes a hub and multiple blades, the multiple blades being spaced apart on the hub, each blade having an edge including a corresponding inner edge at the blade root and an outer edge at the blade tip, as well as a corresponding leading edge and trailing edge, the blades being connected to the hub at the inner edge at the blade root, and the leading edge sweeping forward in an arc shape in the upstream air intake direction; The projection of the outer edge of the blade tip onto a first cross-sectional plane perpendicular to the central axis of the axial flow wind turbine includes: The first arc segment has one end connected to the tail edge, the center of the first arc segment is located on the central axis of the axial flow wind turbine, and the diameter of the first arc segment is D1. The second arc segment has one end connected to the leading edge. The center of the second arc segment is located between the central axis of the axial flow impeller and the inner edge of the blade root. The diameter of the second arc segment is D2, and satisfies D2. <D1。 2. The axial flow impeller according to claim 1, characterized in that, On the first cross-sectional plane, the straight line passing through the midpoint of the angle of the outer edge of the blade tip and the central axis of the axial flow wind turbine is the X-axis, and the straight line perpendicular to the X-axis and passing through the central axis of the axial flow wind turbine is the Y-axis; The distance between the center of the second arc segment and the Y-axis is a, and the distance between the center and the X-axis is b, and the following conditions are met: a is in the range of 0.01 to 0.06 times D1, and b is in the range of 0.01 to 0.07 times D1.

3. The axial flow impeller according to claim 1, characterized in that, The forward sweep angle θ of the blade satisfies: 25°≤θ≤45°.

4. The axial flow impeller according to claim 3, characterized in that, The forward sweep angle θ of the blade satisfies: 35°≤θ≤40°.

5. The axial flow impeller according to claim 1, characterized in that, The forward bending angle γ of the blade satisfies: 25°≤γ≤45°.

6. The axial flow impeller according to claim 5, characterized in that, The forward bending angle γ of the blade satisfies: 35°≤γ≤40°.

7. The axial flow impeller according to claim 1, characterized in that, The inlet mounting angle β1 of the leading edge of the blade is 10°~25°, and the outlet mounting angle β2 of the leading edge is 24°~50°.

8. The axial flow wind turbine according to any one of claims 1-7, characterized in that, It also includes reinforcing ribs that connect the hub and the inner edge of the blade root.

9. An axial flow fan, characterized in that, include: Axial flow wind turbine according to any one of claims 1-8; An electric motor, which is connected to the wheel hub.

10. An air conditioner, characterized in that, Including the axial flow fan according to claim 9.

Images