Fan and air conditioner

Abstract

The utility model relates to the field of air conditioner provides a fan and air conditioner, the fan includes wheel hub and surrounds the wheel hub and sets up a plurality of blades, the blade section symmetry of blade type sets up and forms symmetrical airfoil, the blade has the pressure surface of concave and the suction surface of convex, and the suction surface of airfoil is set up from the symmetry center of airfoil to the direction of moving away from the symmetry center and thinning, wherein, the blade section of blade type is the blade section that is taken by the radial concentric circle of the outer circumference of wheel hub, the utility model discloses a fan, through the thinning of suction surface, when airflow flows to the second half of airfoil, the angle change of wind speed vector slows down, and the total change angle reduces, can make the angle of wind speed vector and fan rotation plane increase when airflow separates from the surface of fan, namely increase the air outlet angle, improve the air volume, make airflow easy to separate from the blade, reduce the vortex loss of wing tail, thereby improve the overall efficiency of fan, reduce the noise, improve user's use experience.

Description

TECHNICAL FIELD

[0001] The utility model relates to air conditioning technical field especially relates to a fan and air conditioner. BACKGROUND

[0002] The traditional axial fan blade adopts asymmetric airfoil, the suction surface is convex outward and the pressure surface is concave inward, when reversing, the original suction surface becomes the pressure surface, which leads to the aggravation of airflow separation and the sharp decline of air volume, and cannot meet the demand of bidirectional air supply.

[0003] In order to solve the above problems, the existing reversible fan adopts symmetric airfoil, the airfoil is completely symmetrical on both sides of the centerline, the suction surface and the pressure surface are interchangeable when the fan is reversed, which can meet the demand of bidirectional air supply and ensure the balance of air volume. The symmetric airfoil of the existing reversible fan has uniform thickness at each part of the blade, and the structure is simple, but the aerodynamic efficiency is low and the noise is high. When the airflow flows to the second half of the airfoil (the original pressure surface becomes the convex suction surface), it is not conducive to the separation of the airflow, and vortex is easily formed, which leads to low overall efficiency of the fan and high working noise. SUMMARY

[0004] The utility model provides a fan and air conditioner to solve the defect that the thickness of the symmetric airfoil is uniform, the airflow angle is small, the airflow is not easy to separate, vortex loss is increased, the suction surface is thinned, the airflow angle is increased, the effective air volume is improved, vortex loss and noise are reduced, and the performance of the fan is improved.

[0005] The utility model provides a fan, which comprises a hub and a plurality of blades arranged around the hub, wherein the blade profile section of the blade is symmetrically arranged to form a symmetric airfoil, the blade has a concave pressure surface and a convex suction surface, and the suction surface of the airfoil is thinned from the symmetric center of the airfoil to the direction away from the symmetric center.

[0006] The blade profile section of the blade is a blade section cut by a radial concentric circle of the outer periphery of the hub.

[0007] According to the fan provided by the utility model, the curvature of the suction surface gradually decreases from the symmetric center of the airfoil to the direction away from the symmetric center.

[0008] According to the fan provided by the utility model, the suction surface comprises a front section, a middle section and a rear section connected in sequence, the thickness of the front section is constant, the middle section and the rear section are thinned, and the thickness of the middle section is smaller than that of the rear section.

[0009] According to the fan provided by the utility model, half of the chord length of the blade profile section is L, and the suction surface is thinned at 0.5L-0.8L from the symmetric center of the airfoil to the direction of the blade end.

[0010] According to the fan, the concave part is formed at 0.5L-0.8L of the suction surface, and the depth of the concave part gradually increases.

[0011] According to the fan, the suction surface is arranged in a wave shape near the end of the blade.

[0012] According to the fan, the suction surface is arranged in a wave shape near the end of the blade.

[0013] According to the fan, the suction surface is arranged in a wave shape near the end of the blade.

[0014] According to the fan, the suction surface is arranged in a wave shape near the end of the blade.

[0015] The utility model also provides a kind of air conditioner, including the fan as described above.

[0016] The fan and air conditioner provided by the utility model, by thinning the suction surface, when airflow flows to the second half of the airfoil, the change of wind speed vector angle slows down, the total change angle reduces, can increase the angle between wind speed vector and fan rotation plane when airflow separates from the surface of fan, that is, increase the outflow angle, improve air volume, make airflow easy to separate from blade, reduce vortex loss of wing tail, thereby improve the overall efficiency of fan, reduce noise, improve user experience. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical scheme of the utility model or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or the prior art description, obviously, the drawings in the following description are some embodiments of the utility model, and for those skilled in the art, other drawings can be obtained without creative labor on the basis of these drawings.

[0018] Figure 1 is the airfoil schematic view of the blade of the reversible fan in the prior art;

[0019] Figure 2 is the structure schematic view of the reversible fan provided by the utility model;

[0020] Figure 3 is the airfoil schematic view of the blade of the reversible fan provided by the utility model.

[0021] Reference signs:

[0022] 10, conventional symmetrical airfoil (prior art);

[0023] 20, hub; 21, blade; 211, blade profile section; 22, pressure surface; 23, suction surface; 24, center of symmetry. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical scheme and advantages of the present application clearer, the technical scheme of the present application will be described clearly and completely below in combination with the drawings in the present application. Obviously, the described embodiments are some embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0025] In the description of the present application, it should be understood that the terms "top", "bottom", "inner", "outer", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0026] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting", "fixing" and the like should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrated; it can be mechanical connection, or electrical connection, or communication; it can be direct connection, or indirect connection through an intermediate medium, or the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0027] In the present application, unless otherwise explicitly specified and limited, the first feature "on" or "under" the second feature can be direct contact of the first and second features, or indirect contact of the first and second features through an intermediate medium. In the description of the present application, the description of the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0028] A reversible fan can deliver air in both directions. The airfoil curve of the reversible fan is symmetrically arranged around the centerline of the airfoil. Airflow enters at a relatively small inlet angle, with the airflow outlet angle being the largest in the middle position, and then gradually decreasing in the latter half. For example... Figure 1 As shown, in a conventional symmetrical airfoil design, the thickness of the blades is relatively uniform. The airflow gradually decreases at the outlet angle in the latter half. The decrease in outlet angle leads to a reduction in the axial velocity component of the airflow, which directly reduces the effective air volume. Moreover, the small angle between the outlet angle and the plane of rotation may result in uneven airflow diffusion and reduced airflow concentration. The airflow is not easy to separate from the blades and is prone to forming vortices. The tail vortices increase mechanical energy loss and reduce the overall efficiency of the fan. Furthermore, the vortex rupture will generate additional aerodynamic noise, affecting the user experience.

[0029] To address the aforementioned issues, this application proposes an airfoil with a thin suction surface to mitigate the adverse effects of the suction surface during air delivery.

[0030] like Figure 2 and Figure 3 As shown, this utility model provides a fan, including a hub 20 and a plurality of blades 21 arranged around the hub 20. The blades 21 have symmetrical airfoil cross-sections 211 arranged to form a symmetrical airfoil. The blades 21 have an inwardly concave pressure surface 22 and an outwardly convex suction surface 23. The suction surface 23 of the airfoil is thinned from the center of symmetry 24 of the airfoil in a direction away from the center of symmetry 24. The blade cross-section 211 of the blades 21 is a cross-section of the blades 21 taken by radial concentric circles on the outer periphery of the hub 20.

[0031] Figure 3 The dashed line represents the curve change of the suction surface 23 without thinning in a typical airfoil design. Comparing it to the solid line on the inner side, thinning the suction surface 23 improves its curvature. When the airflow reaches the rear half of the airfoil, the change in the wind speed vector angle slows down, and the total change angle decreases. This increases the angle between the wind speed vector and the fan's plane of rotation when the airflow leaves the fan surface, thus increasing the outlet angle, increasing airflow, and making it easier for the airflow to leave the blades 21. This reduces vortex losses at the tail, thereby improving the overall fan efficiency, reducing noise, and enhancing the user experience.

[0032] Specifically, the thinning of the suction surface 23 can be done by thinning the entire suction surface 23 or by thinning a portion of it; it can be a continuous and gradual thinning, or a segmented and differentiated thinning or a step-like abrupt thinning. This application does not impose any limitations and can set it according to actual needs. When describing different thinning schemes below, the directional changes referred to in the text are all changes from the center of symmetry 24 of the airfoil to both ends (i.e., the tail).

[0033] In a preferred embodiment of this utility model, the curvature of the suction surface 23 gradually decreases from the center of symmetry 24 of the airfoil toward the direction away from the center of symmetry 24.

[0034] like Figure 3 As shown, this embodiment provides a continuous gradual thinning method, in which the curvature of the suction surface 23 is gradually reduced, which is convenient for processing and can avoid the separation of airflow caused by sudden curvature changes, while also helping to reduce turbulence generation.

[0035] Understandably, in order to reduce the adverse effects on reverse air intake, the thickness of the blade 21 at the tail, i.e., the end blade 21, can remain unchanged or be slightly reduced to ensure the overall performance of the fan.

[0036] In another preferred embodiment of this utility model, from the center of symmetry 24 of the airfoil to the direction away from the center of symmetry 24, the suction surface 23 includes a front section, a middle section and a rear section connected in sequence. The thickness of the front section remains unchanged, while the middle section and the rear section are both thinned. The thickness of the middle section is less than the thickness of the rear section.

[0037] This implementation method employs a segmented, differentiated thinning approach. The thickness of the initial section remains constant to ensure smooth airflow, while the middle section undergoes significant thinning to reduce the outward bulge effect. The final section experiences less thinning to maintain structural strength. This method balances aerodynamic performance and structural strength, and the thinning area can be optimized for specific speeds based on actual needs, improving fan performance while extending its lifespan.

[0038] It is understandable that in other implementations, the thickness of the front section can be slightly reduced without affecting the intake performance.

[0039] In another preferred embodiment of the present invention, half of the chord length of the blade section 211 is L, and the suction surface 23 is thinned at 0.5L-0.8L along the direction from the airfoil's center of symmetry 24 to the end of the blade 21.

[0040] This implementation method thins the suction surface 23 at specific locations, which helps to precisely control the airflow separation point and improve the air delivery effect.

[0041] In some embodiments, the suction surface 23 has a recess at a depth of 0.5L-0.8L, and the depth of the recess gradually increases. By locally thinning the suction surface 23 through concavity, a precise thinning method can be provided, which is convenient for processing. Moreover, when the airflow flows out of the recess, it can form a larger air outlet angle, thereby increasing the air volume and improving the air delivery efficiency.

[0042] Localized thinning can be targeted at a specific chord length. For example, in other embodiments, the thinning area may correspond to 0.5L-0.9L or 0.3L-0.8L, depending on the actual needs.

[0043] In addition to the above methods, the thickness of the suction surface 23 can also be suddenly reduced at a specific location (such as a specific chord length location) to form a stepped transition, so as to adjust the separation point through a specific location.

[0044] Based on the above implementation, the suction surface 23 near the end of the blade 21, i.e. the tail, can adopt a wave shape. While thinning, it is beneficial to break up larger vortices, reduce noise, and optimize noise and aerodynamic efficiency.

[0045] Based on the above embodiments, while the suction surface 23 is thinned, the pressure surface 22 can be compensated for (e.g., locally thickened or with optimized curvature) to maintain the overall airfoil strength. For example, in some embodiments, the pressure surface 22 is locally thickened in the area corresponding to the thinned region of the suction surface 23. For instance, the degree of thickening of the pressure surface 22 is less than the degree of thinning of the suction surface 23; for example, if the suction surface 23 is thinned by 5%-20%, the corresponding position of the pressure surface 22 is thickened by 3%-5%. This avoids a decrease in structural stiffness due to unilateral thinning, thereby extending the structural lifespan.

[0046] Based on the above implementation, the thickness difference of the blade 21 relative to the airfoil's center of symmetry 24 at symmetrical positions does not exceed 10% of the airfoil's maximum thickness. That is, in the airfoil thinning design, the thickness of the blade 21 at each point about the center of symmetry is kept as consistent as possible, although slight differences are allowed to reduce processing precision and ensure product yield.

[0047] During the processing of the fan blade 21 of this application, the thinning of the suction surface 23 can be achieved through CNC milling or 3D printing in a single piece. CNC milling allows for high-precision control of the thinning curvature. By precisely controlling the tool path through a multi-axis CNC machine tool, continuous and gradual thinning of the suction surface curvature can be achieved, avoiding the geometric errors of traditional stamping or casting. This ensures that the symmetry deviation between the suction and pressure surfaces is less than 5%. It is feasible for complex structures, supporting non-uniform thinning schemes such as local concavity and segmented thinning, which are difficult to achieve with traditional processes. For example, it is beneficial for processing wave or sawtooth structures on the tail to reduce eddy current noise. It has wide material adaptability, processing various materials such as aluminum alloys and plastics to meet different strength and lightweight requirements. It is suitable for small-batch production, eliminating the need for high mold costs and helping to control costs. 3D printing technology can directly manufacture suction surface structures with gradient thinning (such as internal hollowing for weight reduction + external wall thinning), breaking through the geometric limitations of traditional processes; it can print an integral impeller with suction surface thinning structure in one go, avoiding the precision loss of split assembly, reducing subsequent processes and improving efficiency; based on simulation data, it can quickly complete the prototype production of different thinning schemes, accelerating the R&D cycle; through lattice structure or hollow design, rigidity can be maintained in the suction surface thinning area (such as internal support trusses), avoiding the risk of deformation under inverted working conditions.

[0048] To ensure the structural strength of the blade 21, which is thinned from the suction surface 23, high-strength lightweight materials such as metals or composite materials (e.g., carbon fiber reinforced polymers, which are directionally reinforced in the thinned area through fiber layup design) can be used for the blade 21. Alternatively, local material modification can be employed, such as shot peening or laser shock peening of the thinned area to improve surface hardness and fatigue resistance. During 3D printing, parameter control can be used to increase the material density of the thinned suction surface area from the inside out. The pressure surface can also be thickened, or a support structure can be designed below the thinned suction surface and integrally formed by 3D printing. Longitudinal reinforcing ribs can be arranged along the chord direction. Rounded corners can be provided in areas of abrupt thickness change in the suction surface (e.g., at the joints of segmented thinning sections) to reduce stress concentration.

[0049] The fan of this application, by thinning the suction surface 23, slows down the change of the wind speed vector angle when the airflow reaches the rear half of the airfoil, and the total change angle is reduced. This increases the angle between the wind speed vector and the fan rotation plane when the airflow leaves the fan surface, thereby increasing the air outlet angle, increasing the air volume, making it easier for the airflow to leave the blades 21, reducing the vortex loss at the tail of the airfoil, thereby improving the overall efficiency of the fan, reducing noise, and improving the user experience.

[0050] This utility model also provides an air conditioner, including the fan described in the above embodiments and examples. The air conditioner has all the beneficial effects described in the above embodiments and examples, which will not be repeated here.

[0051] The air conditioner provided by this utility model, by thinning the suction surface 23, slows down the change of wind speed vector angle when the airflow reaches the rear half of the airfoil, and reduces the total change angle. This increases the angle between the wind speed vector and the fan rotation plane when the airflow leaves the fan surface, thereby increasing the air outlet angle, increasing the air volume, making it easier for the airflow to leave the blades 21, reducing vortex losses at the tail of the airfoil, thereby improving the overall efficiency of the fan, reducing noise, and enhancing the user experience.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A fan comprising a hub (20) and a plurality of blades (21) arranged around the hub (20), characterized in that, The blade (21) has a symmetrical airfoil with a cross section (211) symmetrically arranged. The blade (21) has a concave pressure surface (22) and a convex suction surface (23). The suction surface (23) of the airfoil is thinned from the center of symmetry (24) of the airfoil toward the direction away from the center of symmetry (24). The blade (211) is the blade (21) section cut by the radial concentric circle of the outer periphery of the hub (20).

2. The fan according to claim 1, characterized in that, The curvature of the suction surface (23) gradually decreases from the center of symmetry (24) of the airfoil toward the direction away from the center of symmetry (24).

3. The fan according to claim 1, characterized in that, From the center of symmetry (24) of the airfoil toward the direction away from the center of symmetry (24), the suction surface (23) includes a front section, a middle section and a rear section connected in sequence. The thickness of the front section remains unchanged, while the middle section and the rear section are both thinned. The thickness of the middle section is less than the thickness of the rear section.

4. The fan according to claim 1, characterized in that, The chord length of the airfoil section (211) is half of L. Along the direction from the airfoil's center of symmetry (24) toward the blade (21) end, the suction surface (23) is thinned at 0.5L-0.8L.

5. The fan according to claim 4, characterized in that, The suction surface (23) forms a recess at a depth of 0.5L-0.8L, and the depth of the recess gradually increases.

6. The fan according to any one of claims 1-5, characterized in that, The suction surface (23) is wavy near the end of the blade (21).

7. The fan according to claim 6, characterized in that, The pressure surface (22) is locally thickened in the thinning area corresponding to the suction surface (23).

8. The fan according to any one of claims 1-5, characterized in that, The thickness difference of the blade (21) relative to the airfoil's center of symmetry (24) at symmetrical positions does not exceed 10% of the airfoil's maximum thickness.

9. The fan according to any one of claims 1-5, characterized in that, The thinning of the suction surface (23) is achieved by CNC milling or 3D printing in one piece.

10. An air conditioner, characterized in that, Includes the fan as described in any one of claims 1-9.

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