An air cleaner fan that operates with low noise

Abstract

The utility model relates to fan technical field, concretely relates to a kind of air purifier fan of low-noise operation, it includes: shell, with tapering inlet passage and gradually expanding exhaust passage;Reverse double-stage fan blade system includes: front fan blade, outer edge is equipped with noise reduction sawtooth structure a;Rear fan blade, outer edge is equipped with noise reduction sawtooth structure b, outer diameter is less than front fan blade, through the reverse differential rotation of front fan blade and rear fan blade and sawtooth noise reduction structure cutting and refinement air flow vortex, in combination with the flow field optimization of tapering gradually expanding channel and the boundary layer control of vortex guide vane, inhibit broadband aerodynamic noise from root;While the compact reverse differential mechanism of planetary gear transmission is blocked by shell acoustic packaging and support structure vibration, completely solve the mechanical transmission noise transmission problem of traditional fan, realize the full-band collaborative attenuation of aerodynamic and mechanical noise under the maintenance of high air volume, achieve the effect of energy consumption reduction, comprehensive noise reduction and life improvement.

Description

Technical Field

[0001] This utility model relates to the field of fan technology, specifically to a low-noise air purifier fan. Background Technology

[0002] The fan is the core power component of an air purifier. Its main function is to actively and continuously draw indoor air into the machine through the suction force generated by its rotation. The drawn-in air then flows through various filters inside the machine (such as pre-filters, HEPA filters, activated carbon filters, etc.). These filters capture and remove pollutants such as particulate matter, harmful gases, odors, and microorganisms from the air. After purification, the fan pushes the clean air back into the room with a certain wind pressure and airflow direction, realizing air circulation and continuous purification throughout the space.

[0003] The performance of a fan (such as air volume, noise level, and energy consumption) directly determines the purification efficiency, coverage area, and user experience of an air purifier. However, there are still some problems: 1) conflict between aerodynamic noise and air volume; 2) uncontrolled mechanical vibration transmission chain; 3) secondary noise and energy loss caused by the impact of exhaust turbulence on the duct wall. Therefore, in view of the above situation, there is an urgent need to develop a low-noise air purifier fan to overcome the shortcomings in current practical applications and meet current needs. Utility Model Content

[0004] The purpose of this invention is to provide a low-noise air purifier fan to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a low-noise air purifier fan, comprising:

[0006] The housing has a gradually narrowing intake passage and a gradually expanding exhaust passage;

[0007] A reverse two-stage fan blade system, comprising:

[0008] The front fan blades have a noise-reducing serrated structure on the outer edge.

[0009] The rear fan blade has a noise-reducing serrated structure b on its outer edge. Its outer diameter is smaller than that of the front fan blade, and the number of blades is greater than that of the front fan blade. Moreover, its rotation direction and blade tilt angle are opposite to those of the front fan blade.

[0010] The reverse transmission mechanism includes: an input shaft that drives and connects to the subsequent fan blades; an output shaft that drives and connects to the preceding fan blades; and a gear transmission assembly that connects the input shaft and the output shaft, enabling them to rotate in opposite directions with the input shaft rotating at a higher speed than the output shaft.

[0011] The flow guiding component is located within the gradually expanding exhaust channel;

[0012] The drive motor is fixed inside the flow guide assembly and drives the input shaft.

[0013] Specifically, the reverse rotation of the pre-stage and post-stage fan blades, combined with the synergistic effect of the outer edge noise-reducing sawtooth structure a and noise-reducing sawtooth structure b, effectively cuts airflow vortices and suppresses turbulent noise. The gradually narrowing air intake channel of the housing accelerates airflow intake, while the gradually expanding exhaust channel reduces exhaust resistance. Combined with the rectification effect of the flow guiding component, the flow field distribution is optimized. The gear transmission component of the reverse transmission mechanism drives the input shaft and output shaft to rotate in opposite directions, with the input shaft speed being greater than the output shaft speed. This allows the high-speed pressurization of the post-stage fan blades and the low-speed flow guidance of the pre-stage fan blades to form a pressure gradient match. Under the efficient operation of the drive motor, this achieves high air volume, low energy consumption, and significant noise reduction.

[0014] Preferably, the gear transmission assembly is a planetary gear system, comprising:

[0015] A gear ring fixedly connected to the output shaft;

[0016] The sun gear is fixedly connected to the input shaft;

[0017] Planetary gears that mesh between the ring gear and the sun gear.

[0018] Specifically, a planetary gear system is used as the gear transmission component. The ring gear is fixed to the output shaft to achieve low-speed reverse drive of the front-stage fan blades, while the sun gear is fixed to the input shaft to transmit high-speed power to the rear-stage fan blades. The multi-tooth synchronous meshing of the planetary gears distributes the load and suppresses vibration. It achieves efficient reverse speed difference transmission between the input and output shafts in a compact space, significantly reducing gear meshing noise and improving transmission stability. At the same time, the load-sharing characteristics of the planetary gears reduce shaft wear and extend the service life of the fan.

[0019] Preferably, the reverse transmission mechanism further includes:

[0020] The housing is used to fix the output shaft and cover the gear transmission assembly.

[0021] The mounting base has a bearing fitted on it, and is rotatably connected to the housing through the bearing;

[0022] Support structure, connecting the mounting base to the inner wall of the housing.

[0023] Specifically, the reverse transmission mechanism forms a sealed space by enclosing the gear transmission assembly in a housing, suppressing the leakage of gear meshing noise. At the same time, the fixed connection to the output shaft ensures stable low-speed reverse power output from the front-stage fan blades. The mounting base is rotatably connected to the housing via bearings, achieving rotational decoupling between the output and input shafts and reducing shaft vibration transmission. The support structure rigidly connects the mounting base to the inner wall of the housing, dispersing the gear meshing reaction force while blocking the transmission path of mechanical vibration to the housing. These three components work together to form an acoustic-vibration coupling suppression system, reducing the overall operating noise of the fan.

[0024] Preferably, both noise-reducing sawtooth structure a and noise-reducing sawtooth structure b are biomimetic continuous sawtooth grooves, and their sawtooth depth is 5%-15% of the blade chord length.

[0025] Specifically, noise-reducing sawtooth structures a and b adopt a biomimetic continuous sawtooth groove design, with the sawtooth depth limited to 5%-15% of the blade chord length. Based on biomimetic principles, they accurately reproduce the noise-reducing geometric characteristics of owl feathers: the 5% lower limit ensures effective cutting of mid-to-high frequency eddy noise and suppresses broadband turbulent howling; the 15% upper limit maintains the structural strength of the blade and avoids airflow separation loss; the continuous distribution of sawtooths forms a gradually changing acoustic impedance interface, which allows the airflow boundary layer to transition smoothly, converting the eddy energy at the blade tip into low-frequency steady-state flow. This works in conjunction with the low-speed guiding of the front-stage fan blades and the high-speed pressurization of the rear-stage fan blades to achieve a wind noise reduction of 8-12 dB(A) under all operating conditions with minimal airflow loss.

[0026] Preferably, the ratio of the rate of change of the cross-sectional area of ​​the gradually narrowing intake channel to the rate of change of the gradually expanding exhaust channel is 1:1.1–1:2.

[0027] Specifically, the ratio of the rate of change of the cross-sectional area of ​​the converging intake channel to the expanding exhaust channel is limited to 1:1.1–1:2. Through fluid dynamics optimization, a two-stage noise reduction and efficiency enhancement is achieved: the 1:1.1 area ratio of the converging section ensures that the airflow accelerates smoothly to the optimal operating velocity, avoiding turbulent noise induced by sudden velocity changes; the 1:2 area ratio of the expanding section provides sufficient diffusion space, improving the static pressure recovery efficiency of the high-speed airflow output by the subsequent fan blades; the rate of change gradient matches the low-speed negative pressure zone of the preceding fan blades with the high-speed boosting zone of the subsequent fan blades, eliminating airflow interference and howling, and simultaneously reducing duct resistance. Under the same airflow, the power consumption of the drive motor is reduced, and the noise spectrum peak is attenuated by more than 10dB.

[0028] Preferably, the airflow guiding component includes a vortex-shaped airflow guide vane, the radius of curvature of which decreases along the airflow direction.

[0029] Specifically, the vortex-shaped guide vanes of the flow guiding component adopt a curvature radius design that decreases along the airflow direction. Through streamlined gradual change, the airflow is smoothly guided to change direction: the large curvature radius at the inlet smoothly receives the high-speed rotating airflow of the subsequent fan blades, eliminating vortex disturbances; the continuously decreasing curvature matches the diffusion characteristics of the gradually expanding exhaust channel, suppressing boundary layer separation; the small curvature radius at the outlet enhances axial flow, improves static pressure recovery efficiency, and combined with the reverse flow guiding effect of the front fan blades, significantly reduces the intensity of exhaust turbulence and eliminates harsh noise, achieving wideband attenuation of aerodynamic noise throughout the entire flow channel.

[0030] Compared with the prior art, this utility model provides a low-noise air purifier fan, which has the following beneficial effects:

[0031] By using a sawtooth noise reduction structure to cut and refine the airflow vortex through the counter-rotating differential rotation of the front and rear fan blades, combined with the flow field optimization of the gradually expanding and contracting channels and the boundary layer control of the vortex guide vanes, broadband aerodynamic noise is suppressed at its source. At the same time, the compact counter-rotating differential mechanism of the planetary gear drive, through the acoustic encapsulation of the housing and the vibration isolation of the support structure, completely solves the problem of mechanical transmission noise transmission in traditional fans. While maintaining high airflow, it achieves full-frequency synergistic attenuation of aerodynamic and mechanical noise, resulting in reduced energy consumption, reduced overall noise, and increased lifespan. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of the front structure of this utility model;

[0034] Figure 2 This is a side view of the present invention.

[0035] Figure 3 This is a schematic diagram of the structure of this utility model;

[0036] Figure 4 This is a schematic diagram of the positional relationship of this utility model;

[0037] Figure 5 This is a schematic diagram of the structure of this utility model;

[0038] Figure 6 This is a schematic diagram of the structure of this utility model;

[0039] Figure 7 This is a schematic diagram of the structure of this utility model;

[0040] Figure 8 This is a schematic diagram of the structure of this utility model;

[0041] Figure 9 This is a schematic diagram of the structure of this utility model;

[0042] Figure 10 This is a schematic diagram of the structure of this utility model.

[0043] In the diagram: 10, housing; 110, tapering intake channel; 120, expanding exhaust channel; 20, pre-stage fan blade; 210, noise-reducing sawtooth structure a; 30, post-stage fan blade; 310, noise-reducing sawtooth structure b; 40, reverse transmission mechanism; 410, casing; 420, output shaft; 430, gear transmission assembly; 431, gear ring; 432, sun gear; 433, planetary gear; 440, input shaft; 450, mounting base; 460, support structure; 50, airflow guide assembly; 510, vortex-shaped airflow guide vane; 60, drive motor. Detailed Implementation

[0044] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0045] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; 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.

[0046] Example:

[0047] Please see Figures 1-10 This utility model provides a technical solution: a low-noise air purifier fan, comprising:

[0048] The housing 10 has a gradually narrowing intake passage 110 and a gradually expanding exhaust passage 120;

[0049] A reverse two-stage fan blade system, comprising:

[0050] The front fan blade 20 has a noise-reducing serrated structure a210 on its outer edge;

[0051] The rear fan blade 30 has a noise-reducing serrated structure b310 on its outer edge. Its outer diameter is smaller than that of the front fan blade 20, and the number of blades is greater than that of the front fan blade 20. Moreover, its rotation direction and blade tilt angle are opposite to those of the front fan blade 20.

[0052] The reverse transmission mechanism 40 includes: an input shaft 440, which drives and connects to the rear fan blade 30; an output shaft 420, which drives and connects to the front fan blade 20; and a gear transmission assembly 430, which connects the input shaft 440 and the output shaft 420, so that the two rotate in opposite directions and the speed of the input shaft 440 is greater than the speed of the output shaft 420.

[0053] The flow guiding component 50 is located within the gradually expanding exhaust channel 120;

[0054] The drive motor 60 is fixed inside the flow guide assembly 50 and drives the input shaft 440.

[0055] Specifically, the reverse rotation of the pre-stage fan blade 20 and the post-stage fan blade 30, combined with the synergistic effect of the outer edge noise-reducing sawtooth structure a210 and the noise-reducing sawtooth structure b310, effectively cuts the airflow vortex and suppresses turbulent noise. The tapered intake channel 110 of the housing 10 accelerates airflow intake, and the expanding exhaust channel 120 reduces exhaust resistance. Combined with the rectification effect of the flow guiding component 50, the flow field distribution is optimized. The gear transmission component 430 of the reverse transmission mechanism 40 drives the input shaft 440 and the output shaft 420 to rotate in opposite directions, with the input shaft 440 rotating at a higher speed than the output shaft 420. This allows the post-stage fan blade 30 to pressurize at high speed and the pre-stage fan blade 20 to guide the airflow at low speed, forming a pressure gradient match. Under the efficient operation of the drive motor 60, high air volume, low energy consumption, and significant noise reduction are achieved.

[0056] Preferably, the gear transmission assembly 430 is a planetary gear system, comprising:

[0057] Gear ring 431 is fixedly connected to output shaft 420;

[0058] Sun gear 432 is fixedly connected to input shaft 440;

[0059] Planetary gear 433 meshes between ring gear 431 and sun gear 432.

[0060] Specifically, a planetary gear system is used as the gear transmission component 430. The front-stage fan blade 20 is driven in reverse at low speed by the gear ring 431 being fixedly connected to the output shaft 420. The sun gear 432 is fixedly connected to the input shaft 440 to transmit the high-speed power of the rear-stage fan blade 30. The multi-tooth synchronous meshing of the planetary gear 433 disperses the load and suppresses vibration. It achieves efficient reverse speed difference transmission between the input shaft 440 and the output shaft 420 in a compact space, which significantly reduces gear meshing noise and improves transmission stability. At the same time, the load-sharing characteristics of the planetary gear 433 reduce shaft wear and extend the service life of the fan.

[0061] Preferably, the reverse transmission mechanism 40 further includes:

[0062] The housing 410 is fixedly connected to the output shaft 420 and covers the gear transmission assembly 430;

[0063] Mounting base 450, on which a bearing is fitted, is rotatably connected to housing 410 via the bearing;

[0064] The support structure 460 connects the mounting base 450 to the inner wall of the housing 10.

[0065] Specifically, the reverse transmission mechanism 40 forms a sealed space by covering the gear transmission assembly 430 with the housing 410, which suppresses the leakage of gear meshing noise. At the same time, it fixes the output shaft 420 to ensure stable output of low-speed reverse power from the front fan blades 20. The mounting base 450 is rotatably connected to the housing 410 via bearings, realizing the rotational decoupling of the output shaft 420 and the input shaft 440, reducing the transmission of shaft vibration. The support structure 460 rigidly connects the mounting base 450 to the inner wall of the housing 10, which disperses the reaction force of gear meshing and blocks the transmission path of mechanical vibration to the housing 10. The three work together to form an acoustic vibration coupling suppression system, which reduces the overall operating noise of the fan.

[0066] Preferably, both the noise-reducing sawtooth structure a210 and the noise-reducing sawtooth structure b310 are biomimetic continuous sawtooth grooves, and their sawtooth depth is 5%-15% of the blade chord length.

[0067] Specifically, the noise-reducing sawtooth structure a210 and noise-reducing sawtooth structure b310 adopt a biomimetic continuous sawtooth groove design, with the sawtooth depth limited to 5%-15% of the blade chord length. Based on the principle of bionics, it accurately reproduces the noise-reducing geometric characteristics of owl feathers: the 5% lower limit ensures effective cutting of mid-to-high frequency eddy noise and suppresses broadband turbulent howling; the 15% upper limit maintains the structural strength of the blade and avoids airflow separation loss; the continuous distribution of sawtooth forms a gradually changing acoustic impedance interface, which makes the airflow boundary layer transition smoothly and converts the eddy energy at the blade tip into low-frequency steady-state flow. It works in synergy with the low-speed flow guidance of the front-stage fan blade 20 and the high-speed pressurization of the rear-stage fan blade 30 to achieve a wind noise reduction of 8-12dB(A) and small airflow loss under all operating conditions.

[0068] Preferably, the ratio of the rate of change of the cross-sectional area of ​​the converging intake passage 110 to the expanding exhaust passage 120 is 1:1.1–1:2.

[0069] Specifically, the ratio of the rate of change of the cross-sectional area of ​​the converging intake channel 110 to the expanding exhaust channel 120 is limited to 1:1.1–1:2. Through fluid dynamics optimization, a two-stage noise reduction and efficiency enhancement is achieved: the 1:1.1 area ratio of the converging section 110 ensures that the airflow accelerates smoothly to the optimal working flow rate, avoiding turbulent noise induced by sudden changes in flow rate; the 1:2 area ratio of the expanding section 120 provides sufficient diffusion space, improving the static pressure recovery efficiency of the high-speed airflow output by the subsequent fan blades 30; the rate of change gradient matches the low-speed negative pressure zone of the preceding fan blades 20 and the high-speed boosting zone of the subsequent fan blades 30, eliminating airflow interference and whistling, and simultaneously reducing the duct resistance. Under the same airflow, the power consumption of the drive motor 60 is reduced and the noise spectrum peak is attenuated by more than 10dB.

[0070] Preferably, the flow guiding component 50 includes a vortex-shaped flow guide 510, the radius of curvature of which decreases along the airflow direction.

[0071] Specifically, the vortex-shaped guide vane 510 of the flow guide assembly 50 adopts a curvature radius design that decreases along the airflow direction. The streamlined gradual change guides the airflow to smoothly turn: the large curvature radius at the inlet smoothly receives the high-speed rotating airflow of the subsequent fan blade 30, eliminating vortex disturbance; the continuously decreasing curvature matches the diffusion characteristics of the gradually expanding exhaust channel 120, suppressing boundary layer separation; the small curvature radius at the outlet strengthens axial flow, improves static pressure recovery efficiency, and combined with the reverse flow guidance effect of the front fan blade 20, significantly reduces the exhaust turbulence intensity and eliminates harsh noise, achieving wideband attenuation of aerodynamic noise throughout the entire flow channel.

[0072] Working principle: The fan of this low-noise air purifier is driven by a drive motor 60, which drives the input shaft 440 to rotate the rear fan blades 30 at high speed in the forward direction. At the same time, through the gear transmission assembly 430, the sun gear 432 meshes with the planetary gear 433 and the gear ring 431, causing the output shaft 420, which is fixed to the gear ring 431, to drive the front fan blades 20 in the reverse direction at a low speed. The airflow is accelerated and drawn in through the gradually narrowing intake channel 110. The front fan blades 20 rotate in the reverse direction at a low speed, and the noise-reducing sawtooth structure a210 cuts large-scale vortices. The rear fan blades... The fan blades 30 rotate at high speed in the forward direction, and the noise-reducing sawtooth structure b310 refines the turbulence and increases the pressure. The two-stage fan blades have opposite speeds to form a pressure gradient matching. The treated airflow enters the gradually expanding exhaust channel 120, where the vortex-shaped guide vanes 510 with decreasing curvature guide the airflow to diffuse axially and suppress boundary layer separation. At the same time, the housing 410 covers the gear assembly to block meshing noise, and the support structure 460 is rigidly fixed to block vibration transmission. Finally, the wideband attenuation of aerodynamic and mechanical noise is achieved, resulting in quiet and efficient operation.

[0073] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. A low-noise air purifier fan, characterized in that, include: The housing (10) has a gradually narrowing intake passage (110) and a gradually expanding exhaust passage (120). A reverse two-stage fan blade system, comprising: The front fan blade (20) has a noise-reducing sawtooth structure a (210) on its outer edge. The rear fan blade (30) has a noise-reducing sawtooth structure b (310) on its outer edge. Its outer diameter is smaller than that of the front fan blade (20), and the number of blades is greater than that of the front fan blade (20). Moreover, its rotation direction and blade tilt angle are opposite to those of the front fan blade (20). The reverse transmission mechanism (40) includes: an input shaft (440) driving the subsequent fan blade (30); an output shaft (420) driving the preceding fan blade (20); and a gear transmission assembly (430) connecting the input shaft (440) and the output shaft (420) so that they rotate in opposite directions and the speed of the input shaft (440) is greater than the speed of the output shaft (420). A flow guiding component (50) is disposed within the gradually expanding exhaust channel (120); A drive motor (60) is fixed inside the flow guide assembly (50) and drives the input shaft (440).

2. The low-noise air purifier fan according to claim 1, characterized in that: The gear transmission assembly (430) is a planetary gear system, comprising: A gear ring (431) fixedly connected to the output shaft (420); Sun gear (432) fixedly connected to the input shaft (440); Planetary gear (433) meshes between the gear ring (431) and the sun gear (432).

3. The low-noise air purifier fan according to claim 1, characterized in that: The reverse transmission mechanism (40) further includes: A housing (410) is fixedly connected to the output shaft (420) and covers the gear transmission assembly (430). Mounting base (450), on which a bearing is fitted, is rotatably connected to housing (410) via the bearing; The support structure (460) connects the mounting base (450) to the inner wall of the housing (10).

4. The low-noise air purifier fan according to claim 1, characterized in that: The noise reduction sawtooth structure a (210) and noise reduction sawtooth structure b (310) are both biomimetic continuous sawtooth grooves, and their sawtooth depth is 5%-15% of the blade chord length.

5. The low-noise air purifier fan according to claim 1, characterized in that: The ratio of the rate of change of the cross-sectional area of ​​the gradually narrowing intake channel (110) to the gradually expanding exhaust channel (120) is 1:1.1–1:

2.

6. The low-noise air purifier fan according to claim 1, characterized in that: The flow guiding component (50) includes a vortex-shaped flow guide (510) whose radius of curvature decreases along the airflow direction.

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