Noise-optimized portable fan

Abstract

The application discloses a portable fan with optimized noise, which comprises a fan shell, an air inlet and an air outlet are formed in the fan shell, a fan assembly is modularly assembled in the fan shell, a silencer is arranged in the fan shell, the silencer is located between the fan assembly and the air outlet, and radial silencing holes are formed in the silencer. By arranging the silencer in the fan shell and forming the radial silencing holes in the silencer, when the noise enters the radial silencing holes, a series of physical phenomena such as reflection, interference, friction, collision and heat conduction dissipation occur in the radial silencing holes, so that the noise energy is consumed, and a better noise reduction effect is achieved. The problem that mechanical noise and wind noise are too large due to the increase of the rotating speed of the motor of the existing portable fan is solved.

Description

Technical Field

[0001] This application relates to the field of fans, and more particularly to a noise-optimized portable fan. Background Technology

[0002] In the hot summer, fans have become an essential item for people to relieve the heat. With people's demand for convenient use, lighter and more portable fans are becoming increasingly popular.

[0003] In existing technologies, increasing the fan motor speed is commonly used to achieve a larger air volume, thereby meeting users' demand for strong airflow. However, this approach, which relies solely on increasing the motor speed, brings a significant drawback.

[0004] The inventors of this invention discovered during their research that as the speed of a fan motor continuously increases, mechanical noise and wind noise also become increasingly significant. Mechanical noise primarily originates from the vibration and friction noise generated by the high-speed operation of internal motor components. Wind noise, on the other hand, is caused by factors such as turbulent airflow, airflow separation on the blade surface, and air vortex shedding at the blade edges as the fan blades cut through the air at high speed. This increase in noise not only interferes with the user's normal experience, causing them to suffer from noise disturbance while enjoying the cool breeze, but also reduces the product's comfort and user satisfaction. Utility Model Content

[0005] The purpose of this application is to provide a portable fan that can effectively reduce noise.

[0006] This application provides a noise-optimized portable fan, comprising:

[0007] A fan housing, wherein an air inlet and an air outlet are provided on the fan housing;

[0008] A fan assembly, which is modularly assembled within the fan housing;

[0009] A noise reduction component is disposed within the fan housing and located between the fan assembly and the air outlet. The noise reduction component has radial noise reduction holes.

[0010] Optionally, a buffer is provided between the fan assembly and the muffler, with both ends of the buffer connected to the fan assembly and the muffler, respectively.

[0011] Optionally, the buffer is sleeved on the fan assembly, and the end of the buffer extends in the axial direction of the fan assembly to form a buffer edging. The two ends of the buffer edging are respectively connected to the fan assembly and the muffler.

[0012] Optionally, the noise reduction component includes a noise reduction ring located between the fan assembly and the air outlet, wherein the noise reduction ring has a radial noise reduction hole that radially penetrates the ring wall of the noise reduction ring.

[0013] Optionally, the radial silencing hole includes: a first silencing hole and a second silencing hole, the first silencing hole and the second silencing hole being respectively disposed on the silencing ring, the diameter of the first silencing hole being larger than the diameter of the second silencing hole; and / or,

[0014] A noise reduction gap is provided between the noise reduction ring and the inner wall of the fan housing, and noise reduction cotton is provided in the noise reduction gap, covering the outside of the radial noise reduction hole.

[0015] Optionally, the first silencing hole and the second silencing hole are connected by a slit.

[0016] Optionally, the fan housing is provided with an air outlet seat, the air outlet is opened on the air outlet seat, one end of the noise-absorbing ring is connected to the fan assembly, and the other end of the noise-absorbing ring is connected to the air outlet seat.

[0017] Optionally, the air outlet base includes a connecting ring, which is connected to the fan housing. The connecting ring has a connecting gap at one end facing the silencer ring, and the end of the silencer ring connected to the air outlet base is inserted into the connecting gap.

[0018] Optionally, a connecting flange is provided on the inner sidewall of the silencing ring, and the inner ring sidewall of the connecting ring overlaps the connecting flange, so that the inner ring sidewall of the connecting ring is flush with the inner wall of the silencing ring; and / or,

[0019] The thickness of the end of the silencing ring inserted into the connecting gap decreases along the air outlet direction, and the end of the silencing ring inserted into the connecting gap is located between the inner ring sidewall and the outer ring sidewall of the connecting ring.

[0020] Optionally, along the direction from the air inlet to the air outlet, the connecting baffle is located in front of the radial silencer hole; and / or,

[0021] The air outlet also includes a pressure island and stationary blades connecting the connecting ring and the pressure island. The silencer ring has a positioning notch at one end facing the air outlet, and one end of the stationary blade is inserted into the positioning notch.

[0022] The beneficial effects of this application embodiment are as follows: By setting a silencing component inside the fan housing, and having radial silencing holes on the component, when noise enters the radial silencing holes, a series of physical phenomena such as reflection, interference, friction, collision, and heat conduction dissipation occur inside, causing noise energy to be dissipated, thereby achieving a better noise reduction effect. This solves the problem of excessive mechanical noise and wind noise caused by the increase in motor speed in existing portable fans. Placing the silencing component between the fan assembly and the air outlet ensures that noise is effectively attenuated before it reaches the air outlet. Simultaneously, the fan assembly is modularly assembled inside the fan housing. This design not only facilitates manufacturing and assembly but also makes subsequent maintenance and replacement easier, reducing production costs and after-sales maintenance difficulties, and improving product reliability and service life. Attached Figure Description

[0023] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0024] Figure 1 This is a three-dimensional structural diagram of a portable fan according to a specific embodiment of this application;

[0025] Figure 2 This is a cross-sectional schematic diagram of a portable fan according to a specific embodiment of this application;

[0026] Figure 3 This is a schematic diagram illustrating the scattering and reflection of noise in a radial silencing hole according to a specific embodiment of this application;

[0027] Figure 4 This is an enlarged schematic diagram of the portable fan region A according to a specific embodiment of this application;

[0028] Figure 5 This is a schematic diagram of a second structure of a radial noise-reducing hole according to a specific embodiment of this application;

[0029] Figure 6 This is a schematic diagram of the structure of a muffler according to a specific embodiment of this application;

[0030] Figure 7 This is a schematic diagram of the airflow of a portable fan according to a specific embodiment of this application.

[0031] Figure Descriptions: 1. Fan housing; 11. Air inlet; 12. Air outlet; 13. Air outlet base; 131. Connecting ring; 131a. Connecting gap; 131b. Inner ring sidewall; 131c. Outer ring sidewall; 132. Stationary blade; 133. Pressure boosting island; 2. Fan assembly; 21. Buffer component; 211. Buffer edging; 3. Silencing component; 31. Radial silencing hole; 311. First silencing hole; 312. Second silencing hole; 313. Slit; 32. Positioning notch; 33. Connecting flange; 34. Silencing ring; 35. Silencing cotton; 36. Silencing gap. Detailed Implementation

[0032] To facilitate understanding of this utility model, a more detailed description is provided below with reference to the accompanying drawings and specific embodiments. It should be noted that when an element is described as "fixed to" another element, it can be directly on the other element, or one or more intermediate elements may exist between them. When an element is described as "connected to" another element, it can be directly connected to the other element, or one or more intermediate elements may exist between them. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this specification are for illustrative purposes only.

[0033] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention. The term "and / or" as used in this specification includes any and all combinations of one or more of the associated listed items.

[0034] like Figure 1 , Figure 2 and Figure 3 As shown, a noise-optimized portable fan includes: a fan housing 1, on which an air inlet 11 and an air outlet 12 are provided; a fan assembly 2, which is modularly assembled inside the fan housing 1; and a noise-reducing component 3, which is disposed inside the fan housing 1 and located between the fan assembly 2 and the air outlet 12, and has radial noise-reducing holes 31.

[0035] In this embodiment, the fan housing 1 is assembled from multiple detachable parts. However, the structure of the fan housing 1 is not limited to this. Depending on the specific application scenario, in some embodiments, the structure of the fan housing 1 can be achieved by (but is not limited to): integral injection molding or splicing two half-shells.

[0036] The fan housing 1 is made of plastic material. However, the material used to make the fan housing 1 is not limited to this. Depending on the specific application, in some embodiments, the fan housing 1 can be made by mixing plastic and metal materials. For example, the fan housing 1 can be divided into an inner housing and an outer housing, wherein the outer housing is made of metal and the inner housing is made of plastic. The use of a mixture of metal and plastic materials can improve the physical properties of the fan housing 1, making it more stable and durable.

[0037] Fan assembly 2 includes a fan motor and fan blades. The motor assembly can be (but is not limited to): a single-phase motor, a two-phase motor, or a three-phase motor. The structure of fan assembly 2 can be an external rotor or an internal rotor.

[0038] In the prior art, the fan assembly 2 of a portable fan is connected to the air outlet grille of the fan housing 1. This fixed connection method is not easy to assemble and disassemble. In this embodiment, to facilitate assembly and replacement, the fan assembly 2 is pre-assembled as a modular component, which is directly assembled with the fan housing 1 for use, thus improving assembly and replacement efficiency.

[0039] The modular design of fan assembly 2 provides space for the assembly of the muffler 3. For portable fans with long air ducts, when fan assembly 2 is placed in the middle of the air duct, the distance between fan assembly 2 and air outlet 12 is relatively long, allowing space for the muffler 3 to be placed.

[0040] In this embodiment, the sound-absorbing component 3 can be (but is not limited to): one or more of the following structural combinations: porous sound-absorbing structure, perforated plate resonant sound-absorbing structure, thin film sound-absorbing structure, and thin plate sound-absorbing structure.

[0041] The silencing component 3 has radial silencing holes 31, and the number of radial silencing holes 31 can be two or more.

[0042] The above-described embodiment, by providing a noise-reducing component 3 inside the fan housing 1, and having radial noise-reducing holes 31 on the component 3, allows noise to enter the holes and undergo a series of physical phenomena such as reflection, interference, friction, collision, and heat dissipation, resulting in noise energy loss and achieving a better noise reduction effect. This solves the problem of excessive mechanical and wind noise caused by increased motor speed in existing portable fans. Placing the noise-reducing component 3 between the fan assembly 2 and the air outlet 12 ensures that noise is effectively attenuated before reaching the outlet 12. Furthermore, the modular assembly of the fan assembly 2 within the fan housing 1 facilitates manufacturing and assembly, as well as subsequent maintenance and replacement, reducing production costs and after-sales maintenance difficulties, and improving product reliability and lifespan.

[0043] In some embodiments, a buffer 21 is provided between the fan assembly 2 and the muffler 3, with both ends of the buffer 21 connected to the fan assembly 2 and the muffler 3, respectively.

[0044] The buffer 21 in this embodiment can be made of (but is not limited to): rubber material, foam material, sound-absorbing cotton, air cushion, pulp, etc.

[0045] The buffer 21 can be a separate component disposed between the fan assembly 2 and the muffler 3, or it can be an extension of the buffer structure disposed on the fan assembly 2.

[0046] The fan assembly 2 vibrates during operation. The buffer 21 effectively absorbs this vibration, preventing it from being transmitted to the muffler 3 and avoiding damage or deformation to the internal structure of the muffler 3 due to vibration, thus extending its service life. In actual operation, when the fan assembly 2 rotates at high speed and generates airflow noise, the radial silencing holes 31 on the muffler 3 absorb the noise. Simultaneously, the muffler 3 itself may vibrate due to the impact of sound waves during operation, potentially causing resonance and reducing its silencing effect. The buffer 21 effectively buffers the vibration of the muffler 3 during operation, reducing the risk of resonance that may occur due to the rigid connection between it and the fan assembly 2. The shock absorption effect of the buffer 21 ensures that the muffler 3 can stably perform its sound absorption and noise reduction function, allowing sound waves to be fully reflected, interfered with, and attenuated within the silencing holes, thereby significantly improving the muffler 3's noise absorption and elimination efficiency, resulting in lower fan noise during operation.

[0047] In some embodiments, the buffer 21 is sleeved on the fan assembly 2, and the end of the buffer 21 extends in the axial direction of the fan assembly 2 to form a buffer edge 211. The two ends of the buffer edge 211 are respectively connected to the fan assembly 2 and the muffler 3.

[0048] A buffer 21 is fitted onto the fan assembly 2, with its end buffer edge 211 extending axially and connecting the fan assembly 2 and the muffler 3. When the fan assembly 2 vibrates during operation, the buffer 21 effectively absorbs and buffers these vibrations, reducing the impact of vibration on the entire fan structure, lowering noise caused by vibration, and improving the smoothness and comfort of fan operation. The buffer 21 prevents the severe vibration of the fan assembly 2 from being directly transmitted to the muffler 3, effectively isolating the vibration interference of the fan assembly 2, allowing the muffler 3 to perform its muffler function in a relatively stable state. In this embodiment, the buffer 21 serves as both a buffer structure for the fan assembly 2, reducing the mechanical vibration of the fan assembly 2. Regarding the noise caused by the vibration of the fan assembly 2, the buffer 21 and the muffler 3 form a secondary muffler structure. The buffering effect of the buffer 21 reduces the vibration frequency and amplitude of the fan assembly 2, initially weakening the vibration noise caused by the fan assembly 2, while the muffler 3 further weakens and absorbs the vibration noise transmitted from the fan assembly 2 and facing the airflow direction, playing a secondary vibration noise reduction role. The two-stage vibration noise reduction structure, consisting of buffer 21 and silencing 3, can greatly reduce the spread of vibration noise inside the portable fan into the environment, thus improving the user comfort of the portable fan.

[0049] like Figure 6 As shown, in some embodiments, the noise reduction component 3 includes a noise reduction ring 34, which is located between the fan assembly 2 and the air outlet 12. The noise reduction ring 34 has a radial noise reduction hole 31 that radially penetrates the ring wall of the noise reduction ring 34.

[0050] The noise reduction ring 34 is installed between the fan assembly 2 and the air outlet 12. By opening radial noise reduction holes 31 on the ring wall of the noise reduction ring 34, 360° all-round noise reduction is achieved.

[0051] In some embodiments, the silencing component 3 is composed of multiple silencing plates, each of which has radial silencing holes 31, and the silencing plates are arranged in a circumferential manner at intervals. In some embodiments, the silencing plates are connected by a silencing film.

[0052] like Figure 5 As shown, in some embodiments, the radial silencing hole 31 includes: a first silencing hole 311 and a second silencing hole 312, the first silencing hole 311 and the second silencing hole 312 are respectively disposed on the silencing ring 34, and the diameter of the first silencing hole 311 is larger than the diameter of the second silencing hole 312.

[0053] The silencing ring 34 is equipped with silencing holes of different diameters (first silencing hole 311 and second silencing hole 312), which can effectively silencing noise of different wavelengths (frequency). The first silencing hole 311 has a larger diameter and is mainly for low-frequency noise. This type of noise has a longer wavelength, and the larger diameter allows low-frequency sound waves to enter smoothly and be reflected and interfered inside the silencing hole, thereby achieving energy attenuation. The second silencing hole 312 has a smaller diameter and focuses on silencing high-frequency noise. High-frequency noise has a shorter wavelength, and the smaller diameter can better capture and absorb these high-frequency sound waves. By rationally setting silencing holes of different diameters according to the frequency characteristics of the noise, noise of different wavelengths can be "matched" and accurately enter the corresponding silencing hole for silencing. This avoids the problem of a single-diameter silencing hole being ineffective in silencing some frequency noises, and improves the targeting and efficiency of silencing.

[0054] In some embodiments, the number of the first noise-absorbing hole 311 and the second noise-absorbing hole 312 can be set according to the composition ratio of the noise. When the portable fan has more low-frequency noise, the number of the first noise-absorbing hole 311 is increased; conversely, the number of the second noise-absorbing hole 312 is increased.

[0055] The composition of the radial noise-absorbing hole 31 is not limited to this. Depending on the specific application scenario, in some embodiments, the diameter of the radial noise-absorbing hole 31 may be (but is not limited to): 3, 4, 5, 6 or more.

[0056] In some embodiments, the first silencing hole 311 and the second silencing hole 312 are connected by a slit 313.

[0057] The first silencing aperture 311 and the second silencing aperture 312 respectively silence noise of different wavelengths, while the interconnected design of the slit 313 allows the two silencing apertures to cooperate and work synergistically during the silencing process. When sound waves are reflected and interfered within the silencing apertures, the presence of the slit 313 provides an additional propagation path for the sound waves, causing them to repeatedly reflect, refract, and interfere between the silencing apertures and the slit 313. This increases the travel distance and attenuation frequency of the sound waves during the silencing process, thereby further enhancing the silencing effect. The interconnected slit 313 makes the propagation path of the sound waves within the silencing ring 34 more complex, extending the residence time of the sound waves within the silencing ring 34. The sound waves shuttle between the first silencing aperture 311, the slit 313, and the second silencing aperture 312, constantly being absorbed and attenuated. This complex sound wave path design helps to more effectively capture and eliminate noise of different frequencies, improving the efficiency and uniformity of silencing.

[0058] In some embodiments, a noise reduction gap 36 is provided between the noise reduction ring 34 and the inner wall of the fan housing 1, and a noise reduction cotton 35 is provided in the noise reduction gap 36, covering the outer side of the radial noise reduction hole 31.

[0059] The radial silencing holes 31 on the silencing ring 34 serve as a primary silencing structure, capable of initial absorption and reduction of noise. The silencing cotton 35, acting as a secondary silencing structure, further absorbs the remaining noise after it has passed through the radial silencing holes 31, resulting in double interception and attenuation of noise during propagation, thus significantly improving the overall silencing effect. The silencing cotton 35 covers the outside of the radial silencing holes 31; its porous fiber structure effectively captures and absorbs sound waves, converting sound wave energy into heat or other forms of energy for dissipation. Simultaneously, the silencing cotton 35 also acts as a sound wave reflector, reflecting some sound waves so that they propagate secondary within the radial silencing holes 31, further enhancing the silencing effect.

[0060] In some implementations, the sound-absorbing cotton 35 can be replaced by absorbent materials such as porous sponge or non-woven fabric.

[0061] In some embodiments, a sound-absorbing film is provided at the end of the radial noise-absorbing hole 31 facing the fan housing 1.

[0062] In some embodiments, the fan housing 1 is provided with an air outlet seat 13, the air outlet 12 is opened on the air outlet seat 13, one end of the noise reduction ring 34 is connected to the fan assembly 2, and the other end of the noise reduction ring 34 is connected to the air outlet seat 13.

[0063] The noise reduction ring 34 is positioned between the air outlet seat 13 and the fan assembly 2, which can effectively improve the stability of the noise reduction ring 34 and improve its noise reduction efficiency.

[0064] In some embodiments, the air outlet seat 13 includes a connecting ring 131, which is connected to the fan housing 1. The end of the connecting ring 131 facing the muffler ring 34 has a connecting gap 131a, and the end of the muffler ring 34 connected to the air outlet seat 13 is inserted into the connecting gap 131a.

[0065] The silencer ring 34 is inserted into the connecting gap 131a of the connecting ring 131, making the internal structure of the fan more compact and orderly. The end of the silencer ring 34 is inserted into the connecting gap 131a, preventing it from leaking into the airflow channel. This eliminates the obstruction of airflow by the silencer ring 34, allowing airflow to flow more smoothly from the air outlet 12, reducing airflow turbulence and energy loss caused by structural obstruction, and improving the fan's ventilation efficiency. The tight fit between the silencer ring 34 and the connecting ring 131 better utilizes the sound absorption and insulation functions of the silencer ring 34. Vibrations or sound waves transmitted from the end of the silencer ring 34 enter the connecting gap 131a, forming a closed silencer cavity and improving the noise reduction effect.

[0066] In some embodiments, a connecting flange 33 is provided on the inner sidewall of the muffler ring 34, and the inner ring sidewall 131b of the connecting ring 131 overlaps the connecting flange 33, so that the inner ring sidewall 131b of the connecting ring 131 is flush with the inner wall of the muffler ring 34.

[0067] like Figure 4 As shown, the connecting baffle 33 allows the muffler ring 34 to firmly support the connecting ring 131, ensuring the connecting ring 131 maintains a stable posture and preventing it from shaking or deforming during fan operation, thereby enhancing the stability of the entire air outlet structure. The inner ring sidewall 131b of the connecting ring 131 is flush with the inner wall of the muffler ring 34, eliminating any protrusions or depressions at the connection point of the two components, making the airflow channel smoother and more unobstructed. This significantly reduces the resistance of the airflow when passing through the connection point, reduces energy loss caused by airflow turbulence, and thus effectively improves the fan's airflow efficiency, ensuring that the airflow can be discharged more evenly and quickly.

[0068] In some embodiments, the thickness of one end of the muffler ring 34 inserted into the connecting gap 131a decreases along the air outlet direction, and the end of the muffler ring 34 inserted into the connecting gap 131a is located between the inner ring sidewall 131b and the outer ring sidewall 131c of the connecting ring 131.

[0069] The end of the noise-absorbing ring 34 inserted into the connecting gap 131a is thinner, with its thickness decreasing along the airflow direction. This structure makes its end prone to vibration when airflow passes through. When vibration occurs, because the end is located between the inner ring sidewall 131b and the outer ring sidewall 131c of the connecting ring 131, the vibration cannot be directly transmitted to the connecting ring 131, thus providing a damping effect and reducing the overall vibration of the portable fan. The vibration at the end of the noise-absorbing ring 34 mainly causes air turbulence within the connecting gap 131a. In this way, the energy of the vibration is converted into weak air vibrations, rather than being directly transmitted to the connecting ring 131 to generate greater noise, further enhancing the noise reduction effect and making the portable fan quieter during operation, providing a more comfortable user experience.

[0070] In some embodiments, along the direction from the air inlet 11 to the air outlet 12, the connecting flange 33 is located in front of the radial silencer hole 31.

[0071] In some embodiments, the air outlet seat 13 also includes a pressure island 133 and a stationary blade 132 connecting the connecting ring 131 and the pressure island 133. The silencer ring 34 has a positioning notch 32 at one end facing the air outlet seat 13, and one end of the stationary blade 132 is inserted into the positioning notch 32.

[0072] The air outlet 13 includes a pressure boosting island 133, which compresses and accelerates the airflow, increasing its speed as it exits the air outlet 12, thereby improving airflow efficiency and enhancing the fan's ventilation capacity. The silencer ring 34 has a positioning notch 32 at its end facing the air outlet 13, into which one end of the stationary blade 132 is inserted. This design restricts the rotational freedom of the silencer ring 34, ensuring it remains in a stable position during fan operation and does not rotate due to airflow impact or vibration, thus guaranteeing structural stability. The stationary blade 132 connects the pressure boosting island 133 and the connecting ring 131, helping to guide the airflow and facilitate its smoother exit from the air outlet 12. Simultaneously, the cooperation between the positioning notch 32 and the stationary blade 132 also helps maintain airflow stability, reducing eddies and turbulence generated during airflow exit, further reducing noise.

[0073] It should be noted that any of the embodiments in this example can be implemented independently or in combination with one or more other embodiments. When implementing in combination, the combination method should not be limited to the combination methods listed in this example.

[0074] It should be noted that while preferred embodiments of this application are provided in the specification and accompanying drawings, this application can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are not intended to impose additional limitations on the content of this application; their purpose is to provide a more thorough and comprehensive understanding of the disclosure of this application. Furthermore, the above-described technical features can be combined with each other to form various embodiments not listed above, all of which are considered to be within the scope of this specification. Moreover, those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A noise-optimized portable fan, characterized in that, include: A fan housing, wherein an air inlet and an air outlet are provided on the fan housing; A fan assembly, which is modularly assembled within the fan housing; A noise reduction component is disposed within the fan housing and located between the fan assembly and the air outlet. The noise reduction component has radial noise reduction holes.

2. The noise-optimized portable fan according to claim 1, characterized in that, A buffer is provided between the fan assembly and the muffler, and the two ends of the buffer are respectively connected to the fan assembly and the muffler.

3. The noise-optimized portable fan according to claim 2, characterized in that, The buffer is sleeved on the fan assembly, and the end of the buffer extends in the axial direction of the fan assembly to form a buffer edging. The two ends of the buffer edging are respectively connected to the fan assembly and the muffler.

4. The noise-optimized portable fan according to claim 1, characterized in that, The noise reduction component includes a noise reduction ring located between the fan assembly and the air outlet. The noise reduction ring has radial noise reduction holes that radially penetrate the ring wall.

5. The noise-optimized portable fan according to claim 4, characterized in that, The radial silencing holes include: a first silencing hole and a second silencing hole, the first silencing hole and the second silencing hole being respectively disposed on the silencing ring, the diameter of the first silencing hole being larger than the diameter of the second silencing hole; and / or, A noise reduction gap is provided between the noise reduction ring and the inner wall of the fan housing, and noise reduction cotton is provided in the noise reduction gap, covering the outside of the radial noise reduction hole.

6. The noise-optimized portable fan according to claim 5, characterized in that, The first silencing hole and the second silencing hole are connected by a slit.

7. The noise-optimized portable fan according to claim 4, characterized in that, The fan housing is provided with an air outlet seat, the air outlet is opened on the air outlet seat, one end of the noise-absorbing ring is connected to the fan assembly, and the other end of the noise-absorbing ring is connected to the air outlet seat.

8. The noise-optimized portable fan according to claim 7, characterized in that, The air outlet base includes a connecting ring, which is connected to the fan housing. The end of the connecting ring facing the muffler ring has a connecting gap, and the end of the muffler ring connected to the air outlet base is inserted into the connecting gap.

9. The noise-optimized portable fan according to claim 8, characterized in that, A connecting flange is provided on the inner sidewall of the silencing ring, and the inner ring sidewall of the connecting ring overlaps the connecting flange, so that the inner ring sidewall of the connecting ring is flush with the inner wall of the silencing ring; and / or, The thickness of the end of the silencing ring inserted into the connecting gap decreases along the air outlet direction, and the end of the silencing ring inserted into the connecting gap is located between the inner ring sidewall and the outer ring sidewall of the connecting ring.

10. The noise-optimized portable fan according to claim 9, characterized in that, Along the direction from the air inlet to the air outlet, the connecting baffle is located in front of the radial silencer hole; and / or, The air outlet also includes a pressure island and stationary blades connecting the connecting ring and the pressure island. The silencer ring has a positioning notch at one end facing the air outlet, and one end of the stationary blade is inserted into the positioning notch.

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