Axial flow fan capable of reducing noise and increasing rigidity

Abstract

The utility model relates to the technical field of axial flow fans, in particular to an axial flow fan capable of reducing noise and increasing rigidity, which comprises a hub, a plurality of axial flow blades and a shaft sleeve, the axial flow blades are uniformly distributed along the circumferential direction of the hub, the shaft sleeve is arranged at the center of the hub, and the shaft sleeve is used for connecting a motor shaft. The shaft sleeve is connected with the peripheral side wall of the hub through a plurality of reinforcing ribs arranged in the radial direction. The peripheral side wall of the hub is divided into a plurality of sections of independent arc-shaped side walls by reinforcing ribs which are arranged in the radial direction, the two ends of each section of arc-shaped side wall are connected with the outer ends of the adjacent reinforcing ribs through arc-shaped angles, and the middle of each arc-shaped side wall protrudes outwards relative to the two ends of the arc-shaped side wall to form a streamline curved surface structure. The scheme has the advantages of reducing the operation noise, enhancing the structural rigidity, improving the aerodynamic efficiency and prolonging the service life.

Description

Technical Field

[0001] This utility model relates to the field of axial flow fan technology, and in particular to an axial flow fan that reduces noise and increases rigidity. Background Technology

[0002] Axial fans, as a key component widely used in industrial, home appliance, medical equipment, and air circulation systems, directly affect the ventilation efficiency, noise level, and operational stability of these devices. Traditional plastic axial fans typically consist of a hub, bushing, radial stiffeners, and blades. However, in practical applications, their structural design has many limitations, leading to low product yield, high operating noise, and insufficient rigidity, thus hindering their widespread adoption in high-efficiency, low-noise scenarios. Traditional fans often use a sharp-angle transition design at the junction of the hub and stiffeners. This design is prone to stress concentration during injection molding, causing defects such as whitening and scratches, requiring frequent mold repairs and significantly increasing production costs. Furthermore, sharp-angle areas interfere with airflow, creating localized turbulence and resulting in high-frequency noise during fan operation, especially at high speeds. Secondly, the geometry of conventional blades is relatively simple, lacking airflow guiding structures at the trailing edge, making them prone to trailing-edge vortex separation, further exacerbating noise levels. Simultaneously, insufficient blade rigidity can lead to deformation during high-speed rotation, affecting aerodynamic efficiency and shortening service life. To address these issues, existing technologies urgently need improvement. Summary of the Invention

[0003] To address the aforementioned problems, the purpose of this invention is to provide an axial flow fan that reduces noise and increases rigidity, offering advantages such as reduced operating noise, enhanced structural rigidity, improved aerodynamic efficiency, and extended service life.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] This application provides an axial fan that reduces noise and increases rigidity, the technical solution of which is as follows:

[0006] The device includes a hub, multiple axial flow blades evenly distributed along the circumference of the hub, and a bushing located at the center of the hub, the bushing being used to connect a motor shaft. The bushing is connected to the outer sidewall of the hub by multiple radially arranged reinforcing ribs. The outer sidewall of the hub is divided into multiple independent arc-shaped sidewalls by the radially arranged reinforcing ribs. The two ends of each arc-shaped sidewall are connected to the outer ends of adjacent reinforcing ribs through arc angles, and the middle part of the arc-shaped sidewall protrudes outward compared to the two ends, forming a streamlined curved surface structure.

[0007] Furthermore, this application also proposes that the outer wall at the connection between the outer end of the reinforcing rib and the arc-shaped sidewalls on both sides is constructed as an inwardly concave M-shaped transition surface to optimize airflow separation and reduce turbulence noise.

[0008] Furthermore, this application also proposes that the connection between the outer end of the reinforcing rib and the arc-shaped sidewalls on both sides forms a support area, the thickness of which is greater than that of the adjacent area, so as to provide support for the ejector pin during injection molding and avoid ejection deformation.

[0009] Furthermore, this application also proposes that the trailing edge of the axial flow blade is provided with a continuously distributed serrated structure, wherein the tooth height of the serrated structure is 1 / 20 to 1 / 15 of the blade chord length and the tooth spacing is 2 to 3 times the tooth height, in order to suppress trailing edge vortices and reduce high-frequency noise.

[0010] Furthermore, this application also proposes that two adjacent reinforcing ribs and the outer wall of the bushing and the arc-shaped sidewall between them form a concave cavity, which is used to reduce the overall weight and improve the structural rigidity.

[0011] Furthermore, this application also proposes that multiple blade ribs are provided on the back pressure surface of the axial flow blade, the blade ribs are distributed radially along the axial flow blade, and the length of the blade ribs gradually increases from the inside to the outside in the radial direction; the curvature of the blade ribs is adapted to the curvature of the outer edge of the blade to form a continuous arc structure, which is used to enhance the blade stiffness and optimize the airflow guidance.

[0012] Furthermore, this application also proposes that a plurality of grooves are provided on the back pressure surface of the axial flow blade near the outer edge of the blade, and the grooves are arranged in an arc shape that matches the curvature of the outer edge of the blade, in order to suppress airflow boundary layer separation and reduce noise.

[0013] Furthermore, this application also proposes that a teardrop-shaped protrusion is provided on the back pressure surface of the axial flow blade near the leading edge of the blade, the maximum thickness of the teardrop-shaped protrusion is located in the leading edge direction, and its surface is a smooth transition curved surface, which is used to reduce airflow impact noise and improve aerodynamic efficiency.

[0014] As can be seen from the above, the axial flow fan provided in this application, which reduces noise and increases rigidity, solves the problems of high operating noise, insufficient rigidity and low aerodynamic efficiency of traditional axial flow fans by optimizing the structural design of the hub, reinforcing ribs and blades. It has the advantages of reducing operating noise, increasing structural rigidity, improving aerodynamic efficiency and extending service life. Attached Figure Description

[0015] Figure 1 This is an axial schematic diagram of an axial flow fan provided in this application.

[0016] Figure 2 This is a three-dimensional schematic diagram of an axial fan provided in this application. Detailed Implementation

[0017] 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 intended to explain this utility model, and should not be construed as limiting this utility model.

[0018] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They 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. Therefore, they should not be construed as limitations on this utility model.

[0019] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature 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" has the meaning...

[0020] There are two or more, unless otherwise expressly specified.

[0021] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., 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 according to the specific circumstances.

[0022] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0023] like Figure 1 and 2 As shown, this embodiment relates to an axial flow fan that reduces noise and increases rigidity, including a hub 1, multiple axial flow blades 2 evenly distributed around the circumference of the hub 1, and a bushing 3 located at the center of the hub 1. The bushing 3 is used to connect the motor shaft. The bushing 3 is connected to the outer sidewall of the hub 1 by multiple radially arranged reinforcing ribs 4. The outer sidewall of the hub 1 is divided into multiple independent arc-shaped sidewalls 5 by the radially arranged reinforcing ribs 4. The two ends of each arc-shaped sidewall 5 are connected to the outer ends of adjacent reinforcing ribs 4 by arc angles 6, and the middle part of the arc-shaped sidewall 5 protrudes outward compared to the two ends, forming a streamlined curved surface structure. Specifically, the outer sidewall of the hub 1 is divided into multiple independent arc-shaped sidewalls 5 by the reinforcing ribs 4, and the two ends of each arc-shaped sidewall 5 are connected to the outer ends of adjacent reinforcing ribs 4 by arc angles 6. The middle part of the arc-shaped sidewall 5 protrudes outward compared to the two ends, forming a streamlined curved surface structure. This design reduces turbulence and noise by optimizing the airflow path. Furthermore, the two ends of the arc-shaped sidewall 5 are connected to the outer ends of the adjacent reinforcing ribs 4 through arc-shaped angles 6, making it easier for materials to flow during product injection molding, and eliminating the need to form an ejection area when the mold opens by locally increasing the wall thickness, thereby reducing ejection and tearing, enhancing the overall rigidity 1 of the fan, and improving its operational stability.

[0024] As a preferred embodiment, the streamlined curved surface structure with the outward protrusion in the middle of the arc-shaped sidewall 5 can be achieved through injection molding. Specifically, the mold design can employ an arc-shaped transition surface to ensure that the material can be uniformly filled during injection molding and to avoid stress concentration. In addition, the design of the arc angle 6 can reduce deformation and defects during injection molding by optimizing the ejection mechanism of the mold.

[0025] The technical solution of this application solves the technical problems of reducing noise and increasing rigidity in traditional axial flow fans by optimizing the connection structure between the hub 1 and the reinforcing rib 4. Specifically, the streamlined curved surface design reduces turbulence and noise in the airflow, while the connection method between the arc angle 6 and the reinforcing rib 4 enhances the overall rigidity 1 of the structure, avoiding deformation and defects during the injection molding process. Compared with the prior art, the technical solution of this application improves the fan's operational stability and reduces noise.

[0026] It has significant advantages in this regard.

[0027] Furthermore, the outer wall at the connection between the outer end of the reinforcing rib 4 and the arc-shaped sidewalls 5 on both sides is constructed as an inwardly concave M-shaped transition surface 9. Specifically, the design of the M-shaped transition surface 9 reduces airflow separation at the connection between the reinforcing rib 4 and the arc-shaped sidewalls 5 through a smooth airflow transition, thereby reducing turbulent noise. The design of the M-shaped transition surface 9 optimizes the airflow path, allowing the airflow to pass more smoothly and reducing airflow disturbance at the connection, further reducing the noise level. Moreover, the M-shaped transition surface 9 ensures that the thickness of the reinforcing rib 4 and the arc-shaped sidewalls 5 on both sides does not increase significantly, thus ensuring a relatively consistent product thickness. The shrinkage rate during the cooling process after injection molding is also relatively consistent, thus ensuring product performance. As a preferred embodiment, the concavity depth of the M-shaped transition surface 9 can be adjusted according to specific airflow velocity and noise level requirements to achieve the best noise reduction effect. In addition, the radius of curvature of the M-shaped transition surface 9 can also be optimized according to the geometry of the reinforcing rib 4 and the arc-shaped sidewalls 5 to ensure a smooth airflow transition. Therefore, the technical solution of this application effectively solves the problems of airflow separation and turbulence noise through the design of the M-shaped transition surface 9. Compared with the prior art, this design not only improves the flow efficiency of airflow but also significantly reduces the noise level, while ensuring the consistency and stability of the product.

[0028] Furthermore, the connection between the outer end of the reinforcing rib 4 and the arc-shaped sidewalls 5 on both sides forms a support region 10. The thickness of the support region 10 is greater than that of the adjacent region, which is used to provide support for the ejector pin during injection molding and to prevent deformation during ejection. The design of the support region 10, by using the connection between the outer end of the reinforcing rib 4 and the arc-shaped sidewalls 5 on both sides as the support region 10 and increasing the thickness of this region, provides stronger support. During injection molding and demolding, the ejector pin can effectively support the support region 10, avoiding deformation problems caused by ejection pressure. Compared with the prior art, this design not only enhances the stability of the structure but also ensures the integrity of the mold during demolding, thereby improving the product yield and production efficiency.

[0029] Furthermore, the two adjacent reinforcing ribs 4 and the outer wall of the bushing 3 and the arc-shaped sidewall 5 between them form a concave cavity 14. This design, by combining the reinforcing ribs 4, the outer wall of the bushing 3, and the arc-shaped sidewall 5 into the concave cavity 14 structure, effectively reduces the overall weight of the axial fan 1, while simultaneously enhancing the structural rigidity through the geometry of the concave cavity 14. The formation of the concave cavity 14 not only reduces the amount of material used but also improves the overall stability of the fan through its structural design, thereby solving the problems of heavy weight and insufficient rigidity in traditional axial fans 1. In this regard, the technical solution of this application significantly reduces the overall weight of the axial fan 1 through the design of the concave cavity 14 structure, while simultaneously enhancing the structural rigidity through its geometry. Compared with the prior art, this design not only reduces the amount of material used but also improves the overall stability of the fan through structural optimization, thereby effectively solving the problems of heavy weight and insufficient rigidity in traditional axial fans 1. Therefore, the technical solution of this application has significant advantages in practical applications and can meet the needs of high-efficiency, low-noise scenarios.

[0030] like Figure 1 and 2 As shown, the trailing edge 12 of the axial flow blade 2 is provided with continuously distributed serrated structures 13. The tooth height of the serrated structures 13 is 1 / 20 to 1 / 15 of the blade chord length, and the tooth spacing is 2 to 3 times the tooth height. Specifically, the tooth height and tooth spacing of the serrated structures 13 are specifically designed, with the tooth height being 1 / 20 to 1 / 15 of the blade chord length and the tooth spacing being 2 to 3 times the tooth height. This design...

[0031] The design effectively suppresses the generation of trailing-edge vortices and reduces airflow separation, thereby reducing high-frequency noise. The serrated structure 13 optimizes airflow, reduces turbulence and vortex formation, improves the fan's aerodynamic performance, and reduces operating noise. As a preferred embodiment, the tooth height of the serrated structure 13 can be set to 1 / 18 of the blade chord length, and the tooth spacing is 2.5 times the tooth height. This design, while ensuring the suppression of trailing-edge vortices, further optimizes the airflow characteristics, resulting in a more significant noise reduction effect. Furthermore, the tooth shape of the serrated structure 13 can be triangular, trapezoidal, or other streamlined shapes to adapt to different airflow conditions and noise control requirements. In this application, the technical solution effectively solves the high-frequency noise problem caused by trailing-edge vortices in traditional axial fans 1 by setting continuously distributed serrated structures 13 at the trailing edge 12. Compared with existing technologies, this solution not only significantly reduces noise but also improves the fan's aerodynamic performance by optimizing airflow. This design ensures efficient fan operation while further improving the user experience, demonstrating high practicality and innovation.

[0032] Furthermore, multiple blade ribs 16 are provided on the back pressure surface 15 of the axial flow blade 2. These ribs are distributed radially along the blade 2, and their length gradually increases from the inside to the outside in the radial direction. The curvature of the blade ribs 16 matches the curvature of the outer edge 17 of the blade, forming a continuous arc-shaped structure. Specifically, the blade ribs 16 can be arranged in various ways. For example, the blade ribs 16 can be integrally formed using the same material as the blade 2, or fixed to the blade 2 by welding, bonding, or other methods. The cross-sectional shape of the blade ribs 16 can be rectangular, trapezoidal, or other suitable shapes to enhance their rigidity and strength. In addition, the distribution density and number of blade ribs 16 can be adjusted according to the size and design requirements of the blade 2 to achieve optimal rigidity and airflow guidance. In this regard, this technical solution effectively enhances the overall rigidity of the blade 2 and reduces the deformation of the blade 2 during high-speed rotation by increasing the length and curvature of the blade ribs 16. Meanwhile, the continuous arc-shaped structure optimizes airflow guidance, reduces airflow separation and turbulence, thereby improving the fan's aerodynamic efficiency and operational stability. Compared with existing technologies, this solution significantly improves the rigidity and aerodynamic performance of the blades while maintaining their lightweight design, solving the technical problems of insufficient rigidity and unoptimized airflow guidance in traditional axial fans.

[0033] Furthermore, on the back pressure surface 15 of the axial flow blade 2, a plurality of grooves 18 are provided near the outer edge 17 of the blade. The grooves 18 are arranged in an arc shape that matches the curvature of the outer edge 17 of the blade. Specifically, the shape and size of the grooves 18 can be adjusted according to actual needs. For example, the depth, width, and spacing of the grooves 18 can be optimized based on the curvature of the outer edge 17 of the blade and the airflow characteristics. As a preferred embodiment, the depth of the grooves 18 can be 1 / 10 to 1 / 5 of the thickness of the blade 2, the width can be 1 / 20 to 1 / 15 of the blade chord length, and the spacing can be 2 to 3 times the width of the grooves 18. In addition, the arrangement of the grooves 18 can also be adjusted according to the curvature of the outer edge 17 of the blade. For example, the grooves 18 can be arranged along the tangent direction of the outer edge 17 of the blade or along the normal direction of the outer edge 17 of the blade. Therefore, by providing multiple grooves 18 on the back pressure surface 15 of the axial flow blade 2, and arranging these grooves 18 along the arc of the outer edge 17 of the blade, airflow boundary layer separation can be effectively suppressed, thereby reducing noise. The arc-shaped arrangement of the grooves 18 matches the arc of the outer edge 17 of the blade, further optimizing airflow and reducing turbulence and noise generation. Compared with the prior art, the technical solution of this application, through the distribution and shape of the grooves 18, can more effectively suppress airflow boundary layer separation, thereby significantly reducing noise levels and improving the performance of the axial flow fan 1.

[0034] Furthermore, on the back pressure surface 15 of the axial flow blade 2, a teardrop-shaped protrusion 20 is provided near the leading edge 19 of the blade. The maximum thickness of the teardrop-shaped protrusion 20 is located in the leading edge direction, and its surface is a smoothly transitioned curved surface, which is used to reduce airflow impact noise and improve aerodynamic efficiency. The maximum thickness of the teardrop-shaped protrusion 20 is located in the leading edge direction. This design helps to optimize airflow and reduce airflow impact at the leading edge 19, thereby reducing noise. The design of the smoothly transitioned curved surface allows airflow to flow more smoothly over the surface of the blade 2, reducing airflow separation and turbulence, and further improving aerodynamic efficiency. Specifically, the shape of the teardrop-shaped protrusion 20 can be achieved in various ways, such as by adopting a streamlined design to make its surface smoothly transition and avoid airflow separation at the protrusion. In addition, the thickness and position of the teardrop-shaped protrusion 20 can be adjusted according to specific airflow conditions to achieve the best noise reduction and efficiency improvement effect. Through the above technical solution, this application can effectively reduce airflow impact noise and improve aerodynamic efficiency. The teardrop-shaped protrusion 20, with its maximum thickness located at the leading edge and a smooth transition surface design, optimizes airflow and reduces airflow impact at the leading edge 19, thereby lowering noise. Simultaneously, the smooth transition surface design allows airflow to pass more smoothly over the blade 2 surface, reducing airflow separation and turbulence, further improving aerodynamic efficiency. Compared to existing technologies, the technical solution of this application has significant advantages in noise reduction and efficiency improvement, effectively solving practical technical problems.

[0035] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is 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.

[0036] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention.

Claims

1. A kind of axial fan of reducing noise and increasing rigidity, comprising hub (1), multiple axial blades (2) being evenly distributed along the circumference of the hub (1), and shaft sleeve (3) being arranged at the center of the hub (1), the shaft sleeve (3) is used to connect motor shaft;The shaft sleeve (3) and the peripheral side wall of hub (1) are connected by multiple radial reinforcing ribs (4), it is characterized by: The peripheral side wall of the hub (1) is divided into multiple independent arc side walls (5) by radial reinforcing rib (4), the two ends of each arc side wall (5) are connected with the outer end of adjacent reinforcing rib (4) by arc angle (6), and the middle part of the arc side wall (5) is convex outward compared with the two ends, forming a streamline curved surface structure.

2. The axial fan according to claim 1, wherein: The outer end of the reinforcing rib (4) and the connecting place of the arc side wall (5) on both sides are configured as inwardly recessed M-shaped transition curved surface (9), to optimize airflow separation and reduce turbulent noise.

3. The axial fan according to claim 1 or 2, wherein: The outer end of the reinforcing rib (4) and the connecting place of the arc side wall (5) on both sides form a supporting area (10), the thickness of the supporting area (10) is greater than that of the adjacent area, to provide support for ejector rod when injection molding, avoiding ejection deformation.

4. The axial fan according to claim 1, wherein: The trailing edge (12) of the axial blade (2) is provided with a continuous distribution of sawtooth structure (13), the tooth height of the sawtooth structure (13) is 1 / 20 to 1 / 15 of the blade chord length, and the tooth spacing is 2 to 3 times the tooth height, to suppress trailing edge vortex and reduce high-frequency noise.

5. The axial fan according to claim 1, wherein: Two adjacent reinforcing ribs (4) and the outer wall of the shaft sleeve (3) and the arc side wall (5) between them enclose a cavity (14), to reduce the overall weight and improve structural rigidity.

6. The axial fan according to claim 1, wherein: A plurality of blade ribs (16) are provided on the back pressure surface (15) of the axial blade (2), the blade ribs (16) are distributed along the radial direction of the axial blade (2), and the length of the blade ribs (16) gradually increases from inside to outside in the radial direction; The curvature of the blade rib (16) is adapted to the curvature of the blade outer edge (17), forming a continuous circular arc structure, to enhance the rigidity of the blade and optimize airflow guidance.

7. The axial fan according to claim 1 or 6, wherein: A plurality of grooves (18) are provided on the back pressure surface (15) of the axial blade (2) near the blade outer edge (17), the grooves (18) are arranged along the circular arc that is adapted to the curvature of the blade outer edge (17), to suppress airflow boundary layer separation and reduce noise.

8. The axial fan according to claim 1, wherein: The back pressure surface (15) of the axial flow blade (2) is provided with a water-drop-shaped protrusion (20) near the blade leading edge (19), the maximum thickness of the water-drop-shaped protrusion (20) is in the direction of the leading edge, and the surface thereof is a smooth transition curved surface, for reducing airflow impact noise and improving aerodynamic efficiency.

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