Multi-vane noise reducing blower fan blade

Abstract

This utility model belongs to the field of fan blade technology and discloses a multi-blade noise-reducing blower fan blade, including: a fan blade assembly comprising 53 forward-curved fan blades evenly distributed along the circumference of a hub, with a motor mounting cavity at the center of the hub; the axial end face of the hub has several heat dissipation holes, arranged equidistantly along the circumference to form an annular heat dissipation channel; a motor assembly comprising a thickened silicon steel sheet frame, the silicon steel sheet thickness being 0.5-0.8mm; the ratio of the fan blade diameter D to the fan outer diameter D0 is 75%-78%; this utility model, by using 53 forward-curved fan blades with an optimized bending angle of 15°-25°, and a chord length ratio of the leading edge to the trailing edge of the blades of 1:0.8-1:0.9, effectively suppresses turbulence and eddy noise. An arc-shaped transition section with a transition radius R = 3-5mm is provided at the connection between the hub and the fan blades to reduce airflow separation noise.

Description

Technical Field

[0001] This utility model relates to the field of fan blade technology, and in particular to a multi-blade noise-reducing blower fan blade. Background Technology

[0002] In fields such as industrial blowers and air conditioning ventilation systems, traditional blower blades generally adopt a backward-curved or straight plate design, which presents the following technical problems:

[0003] Traditional fan blades are prone to generating turbulence and eddy noise at high speeds, especially at high speeds where sound pressure levels often exceed 60dB, severely impacting user comfort. The integrated design of the hub and motor assembly suffers from a single heat dissipation structure, leading to localized overheating during operation and affecting motor lifespan and the thermal stability of the fan blade material. Existing fan blades are mostly made of ordinary plastics or metals, making it difficult to achieve a balance between lightweight, high strength, and low friction, resulting in high energy consumption and limited efficiency. An improper match between the inlet cross-sectional area and the fan blade sweeping area easily causes airflow separation and impact noise, reducing overall aerodynamic efficiency. Utility Model Content

[0004] The main objective of this invention is to provide a multi-blade noise-reducing blower blade, aiming to solve the problem of turbulent and eddy noise generated by traditional fan blades during high-speed rotation, especially at high speeds where the sound pressure level often exceeds 60dB, severely impacting the comfort of the operating environment. In the integrated design of the hub and motor assembly, the heat dissipation structure is singular, leading to localized overheating during operation, affecting motor lifespan and the thermal stability of the fan blade material. Existing fan blades mostly use ordinary plastics or metals, making it difficult to simultaneously achieve lightweight, high strength, and low friction characteristics, resulting in high energy consumption and limited efficiency. Furthermore, the mismatch between the inlet cross-sectional area and the fan blade sweeping area easily causes airflow separation and impact noise, reducing overall aerodynamic efficiency.

[0005] To achieve the aforementioned objectives of this utility model, the first aspect of this utility model proposes a multi-blade noise-reducing blower fan blade, comprising:

[0006] The fan blade assembly comprises 53 forward-curved fan blades evenly distributed along the circumference of the hub, and the hub has a motor mounting cavity at its center.

[0007] The axial end face of the hub is provided with several heat dissipation holes, which are arranged at equal intervals along the circumference to form an annular heat dissipation channel.

[0008] The motor assembly includes a thickened silicon steel sheet wire frame, with the silicon steel sheet thickness being 0.5-0.8mm;

[0009] The ratio of fan blade diameter D to fan outer diameter D0 is 75%-78%.

[0010] Furthermore, the ratio of the axial thickness of the forward-curved fan blades to the overall thickness of the fan is 55%-60%.

[0011] Furthermore, the bending angle of the forward-curved fan blade is 15°-25°, and the chord length ratio between the leading edge and trailing edge of the blade is 1:0.8-1:0.9.

[0012] Furthermore, the axial distance between the fan blade assembly and the air inlet is 3.5-4.2 mm.

[0013] Furthermore, the surface of the forward-curved fan blade is provided with a nano-scale hydrophobic coating with a thickness of 50-100 nm.

[0014] Furthermore, the fan blade assembly is injection molded using PA66+30%GF composite material, with the molding shrinkage rate controlled at 0.3%-0.5%.

[0015] Furthermore, the hub and the forward-curved fan blades are connected by an arc-shaped transition section with a transition radius R = 3-5 mm and a surface roughness Ra ≤ 0.8 μm.

[0016] Furthermore, the air inlet is provided with a flared structure, with a diffusion angle θ = 15°-25° and a guide length L = 0.2D-0.25D.

[0017] Furthermore, the ratio of the air inlet cross-sectional area S to the fan blade sweep area S0 is 80%-85%.

[0018] Furthermore, the thickness tolerance of the silicon steel sheet wire frame is controlled within ±0.05mm, and the sound pressure level of the motor assembly at a distance of 100mm from the air outlet is ≤53dB under the rated speed of 4500±200rpm.

[0019] Beneficial effects:

[0020] 1. This utility model employs 53 forward-curved fan blades with an optimized curvature angle of 15°-25°, coupled with a chord length ratio of 1:0.8-1:0.9 between the leading and trailing edges of the blades, effectively suppressing turbulence and eddy noise. An arc-shaped transition section with a radius R = 3-5mm is provided at the junction of the hub and the fan blades to reduce airflow separation noise. The air inlet is designed with a flared structure with a diffusion angle θ = 15°-25° and a guide length L = 0.2D-0.25D, ensuring smooth airflow acceleration and reducing impact noise.

[0021] 2. This utility model features 2.2mm diameter heat dissipation holes on the axial end face of the hub, arranged equidistantly along the circumference to form an annular heat dissipation channel, optimizing airflow convection heat dissipation efficiency. The motor assembly uses thickened silicon steel sheet wire frame, with the stack thickness tolerance controlled within ±0.05mm, reducing hysteresis loss and eddy current loss, and minimizing operating temperature rise.

[0022] 3. This utility model utilizes PA66+30%GF composite material for the fan blade assembly via injection molding, with a shrinkage rate controlled at 0.3%-0.5%, achieving both high strength and lightweight characteristics. The forward-curved fan blade surface is coated with a nano-level hydrophobic coating to reduce droplet adhesion and surface roughness, thereby lowering airflow friction noise. The axial distance between the fan blade assembly and the air inlet is controlled at 3.5-4.2mm, and the ratio of the air inlet cross-sectional area S to the fan blade swept area S0 is 80%-85%, optimizing airflow distribution and reducing localized eddies. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of a multi-blade noise-reducing blower fan blade according to an embodiment of the present invention;

[0024] Figure 2 This is a top view of the fan blades of a multi-blade noise-reducing blower according to an embodiment of the present invention;

[0025] Figure 3 This is a cross-sectional view of the fan blades of a multi-blade noise-reducing blower according to an embodiment of the present invention;

[0026] Figure 4 This is an embodiment of the multi-blade noise-reducing blower fan blades of this utility model. Figure 3 Enlarged view of point A in the middle.

[0027] in:

[0028] 1-Fan blade assembly; 11-Hub; 12-Forward curved fan blade; 13-Heat dissipation hole; 14-Flame mouth structure; 2-Motor assembly; 121-Leading edge of blade; 122-Leading edge of blade; 101-Motor mounting cavity; 102-Arc transition section.

[0029] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0030] It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0031] 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," "outer," "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. They 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, 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, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly and specifically defined.

[0032] 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, a direct connection, or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between 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.

[0033] 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.

[0034] Reference Figures 1-4 An embodiment of this utility model provides a multi-blade noise-reducing blower fan blade, comprising:

[0035] The fan blade assembly 1 includes 53 forward-curved fan blades 12 evenly distributed around the circumference of the hub 11, and the hub 11 has a motor mounting cavity 101 at its center.

[0036] The axial end face of the hub 11 is provided with a number of heat dissipation holes 13, which are arranged at equal intervals along the circumference to form an annular heat dissipation channel.

[0037] Motor assembly 2 includes a thickened silicon steel sheet wire frame, the silicon steel sheet having a thickness of 0.5-0.8mm;

[0038] The ratio of fan blade diameter D to fan outer diameter D0 is 75%-78%. The thickness tolerance of the silicon steel sheet wire frame is controlled within ±0.05mm. The sound pressure level of the motor assembly 2 at a rated speed of 4500±200rpm is ≤53dB at a distance of 100mm from the air outlet.

[0039] In this embodiment, the hub 11 is injection molded from high-strength engineering plastic, and has a motor mounting cavity 101 at its center for embedding the motor assembly 2. The axial end face of the hub 11 has several heat dissipation holes 13 with a diameter of 2.2 mm, arranged equidistantly along the circumference to form an annular heat dissipation channel. The arrangement density of the heat dissipation holes 13 is optimized based on thermodynamic simulation results to ensure effective heat dissipation during high-speed rotation, while avoiding airflow disturbance caused by excessively large pores.

[0040] Motor assembly 2 uses a thickened silicon steel sheet wire frame, with a silicon steel sheet thickness of 0.5-0.8mm and a stacking thickness tolerance controlled within ±0.05mm. The thickened design reduces hysteresis loss and eddy current loss, thereby reducing motor operating noise. Motor assembly 2 is embedded in the motor mounting cavity 101 of hub 11, and coaxiality with fan blade assembly 1 is ensured through assembly.

[0041] Optionally, the ratio of the axial thickness of the forward-curved fan blade 12 to the overall thickness of the fan is 55%-60%. This ratio balances structural strength and airflow resistance.

[0042] The forward-curved fan blade 12 has a curvature angle of 15°-25°, and the chord length ratio of the leading edge 121 to the trailing edge 122 is 1:0.8-1:0.9. The fan blade assembly 1 comprises 53 forward-curved fan blades 12 evenly distributed circumferentially along the hub 11. The forward-curved fan blades 12 employ a forward-curved structure with a curvature angle of 15°-25° and a chord length ratio of the leading edge 121 to the trailing edge 122 of 1:0.8-1:0.9. This design reduces turbulence noise by optimizing airflow separation characteristics.

[0043] The axial distance between the fan blade assembly 1 and the air inlet is 3.5-4.2 mm. This distance is optimized through fluid dynamics simulation to reduce airflow impact noise at the air inlet and avoid airflow blockage caused by excessively small distances.

[0044] Optionally, the surface of the forward-curved fan blade 12 is coated with a nanoscale hydrophobic coating with a thickness of 50-100 nm. This coating is prepared by spraying or chemical deposition and is composed of low surface energy nanoparticles and silicone resin, with the low surface energy nanoparticles being, for example, fluorinated micro / nanoparticles. The hydrophobic coating reduces droplet adhesion and surface roughness, further reducing airflow friction noise.

[0045] The fan blade assembly 1 is injection molded from PA66+30%GF composite material, with a molding shrinkage rate controlled within 0.3%-0.5%. The fan blade assembly 1 is also injection molded from PA66+30%GF glass fiber composite material. This material possesses high mechanical strength (tensile yield strength ≥130MPa), good dimensional stability, a shrinkage rate of 0.3%-0.5%, and wear resistance, while also meeting lightweight requirements. During the injection molding process, the curvature of the fan blades and the surface roughness Ra≤0.8μm are controlled through the mold.

[0046] The hub 11 and the forward-curved fan blade 12 are connected by an arc-shaped transition section 102 with a transition radius R = 3-5 mm and a surface roughness Ra ≤ 0.8 μm. The arc-shaped transition section 102, with its smooth curved surface design, reduces stress concentration and minimizes turbulence during airflow.

[0047] The air inlet is equipped with a flared structure 14, with a diffusion angle θ = 15°-25° and a guide length L = 0.2D-0.25D, where D is the fan blade diameter. The flared structure 14, through its gradually expanding design, allows the airflow to smoothly and rapidly enter the fan blade area, reducing airflow separation noise.

[0048] The ratio of the inlet cross-sectional area to the fan blade sweep area is 80%-85%. The ratio of the inlet cross-sectional area S to the fan blade sweep area S0 is 80%-85%. This ratio has been experimentally verified and can effectively balance airflow velocity and pressure loss, and reduce eddy noise.

[0049] Description: Fan blade assembly 1 is made of PA66+30%GF composite material, and is injection molded using precision molds, with the shrinkage rate controlled within the range of 0.3%-0.5%. A nano-level hydrophobic coating is sprayed or chemically deposited onto the surface of the forward-curved fan blade 12 to ensure uniform coating thickness. Thickened silicon steel sheet wire frames are stacked, with the stack thickness tolerance controlled at ±0.05mm, and embedded into the motor mounting cavity 101 of the hub 11. Dynamic balancing tests are used to correct the rotational balance between motor assembly 2 and fan blade assembly 1, reducing vibration and noise. The axial distance between fan blade assembly 1 and the air inlet is adjusted to 3.5-4.2mm to ensure that the flared structure 14 matches the fan blade sweeping area.

[0050] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. Any equivalent structural or procedural transformations made based on the content of the present utility model specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present utility model.

Claims

1. A multi-blade noise-reducing blower blade, characterized in that, include: The fan blade assembly (1) includes 53 forward-curved fan blades (12) evenly distributed along the circumference of the hub (11), and the hub (11) has a motor mounting cavity (101) at its center; The hub (11) has several heat dissipation holes (13) on its axial end face, which are arranged at equal intervals along the circumference to form an annular heat dissipation channel; The motor assembly (2) includes a thickened silicon steel sheet wire frame with a silicon steel sheet thickness of 0.5-0.8 mm; The ratio of fan blade diameter D to fan outer diameter D0 is 75%-78%.

2. The multi-blade noise-reducing blower blade according to claim 1, characterized in that, The ratio of the axial thickness of the forward-curved fan blade (12) to the overall thickness of the fan is 55%-60%.

3. The multi-blade noise-reducing blower blade according to claim 1, characterized in that, The bending angle of the forward-curved fan blade (12) is 15°-25°, and the chord length ratio of the leading edge (121) to the trailing edge (122) of the blade is 1:0.8-1:0.

9.

4. The multi-blade noise-reducing blower blade according to claim 1, characterized in that, The axial distance between the fan blade assembly (1) and the air inlet is 3.5-4.2 mm.

5. The multi-blade noise-reducing blower blade according to claim 1, characterized in that, The surface of the forward-curved fan blade (12) is provided with a nano-scale hydrophobic coating with a thickness of 50-100nm.

6. The multi-blade noise-reducing blower blade according to claim 1, characterized in that, The fan blade assembly (1) is injection molded using PA66+30%GF composite material, with the molding shrinkage rate controlled at 0.3%-0.5%.

7. The multi-blade noise-reducing blower blade according to claim 1, characterized in that, The hub (11) is provided with an arc-shaped transition part (102) at the connection between it and the forward-curved fan blade (12), with a transition radius R = 3-5 mm and a surface roughness Ra ≤ 0.8 μm.

8. The multi-blade noise-reducing blower blade according to claim 4, characterized in that, The air inlet is provided with a flared structure (14), with a diffusion angle θ = 15°-25° and a guide length L = 0.2D-0.25D.

9. The multi-blade noise-reducing blower blade according to claim 8, characterized in that, The ratio of the air inlet cross-sectional area to the fan blade sweeping area is 80%-85%.

10. The multi-blade noise-reducing blower blade according to claim 1, characterized in that, The thickness tolerance of the silicon steel sheet wire frame is controlled within ±0.05mm. The sound pressure level of the motor assembly (2) at a distance of 100mm from the air outlet is ≤53dB when the rated speed is 4500±200rpm.

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