Noise reduction device and dust collection fan
Patent Information
- Application Number
- CN202522658215.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-15
- Publication Date
- 2026-10-27
- Estimated Expiration
- 2035-12-15
Smart Images
Figure CN224903594U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of fan noise reduction technology, specifically to a noise reduction device for a dust collection fan, and a dust collection fan. Background Technology
[0002] Dust collection fans are commonly used in household or commercial cleaning equipment. They create negative pressure to draw dust and fine particles into a collection chamber. These fans typically have a high-speed rotating impeller in the intake section to provide suction, and a motor in the motor section to drive the impeller. The overall structure is usually compact and axially arranged to facilitate installation in confined spaces.
[0003] Most existing dust collection fans adopt a single-layer cylindrical shell structure. Inside the shell, the impeller, motor, and corresponding air inlet, exhaust outlet, and internal air duct are arranged sequentially along the axial direction. Specifically, the motor is located inside the shell and is arranged coaxially with the impeller. The impeller is usually located at one end of the shell and directly opposite the air inlet, while the other end forms the exhaust channel. The air duct structure is mostly set along the inner wall of the shell or formed by guide components.
[0004] Dust collectors inevitably generate noise during operation, including aerodynamic noise from the high-speed rotation of the impeller, as well as electromagnetic and mechanical vibration noise from the motor. However, single-layer shell structures have inherent limitations in noise control. On the one hand, the limited space between the shell and the noise source makes it difficult to arrange sound-absorbing or vibration-damping structures for different noise types. On the other hand, to balance strength, volume, and production costs, single-layer shells often cannot simultaneously fulfill the combined functions of structural support, airflow organization, and acoustic vibration reduction, resulting in limited overall noise attenuation capabilities.
[0005] To improve noise reduction performance, existing technologies have proposed using a double-shell structure, which involves adding an outer shell to the inner shell, forming a sound-insulating interlayer between the two. Theoretically, the double-shell structure can improve sound insulation against some mid-to-high frequency noise by utilizing the combined mass of the shells and the impedance difference of the interlayer air layer. Compared to a single-shell structure, this structure can indeed reduce the direct propagation of noise to a certain extent.
[0006] However, existing double-shell structures still have significant limitations. Because the distance between the inner and outer shells is fixed, the interlayer space often only provides good sound insulation for specific frequency bands, while its ability to suppress low-frequency noise and broadband noise is insufficient. Furthermore, the interlayer typically lacks effective sound-absorbing materials, easily leading to cavity resonance, which can actually amplify noise at certain frequencies. Therefore, the noise reduction performance of traditional double-shell structures still falls short of the high-efficiency noise reduction requirements of dust collector fans in compact spaces. Utility Model Content
[0007] The purpose of this invention is to provide a noise reduction device and a dust collection fan including the noise reduction device, so as to solve the problems that the existing single-layer shell structure has limited noise reduction effect and the traditional double-shell structure cannot effectively deal with wide-band noise. Thus, without affecting the fan efficiency, it can achieve synergistic suppression of noise in different frequency bands and improve the overall noise reduction performance of the whole machine.
[0008] To achieve the above objectives, this utility model provides a noise reduction device, comprising: Inner shell; An outer shell is fitted over the outer side of the inner shell, and a sound-absorbing space is formed between the outer shell and the inner shell; The noise reduction component includes a low-frequency noise reduction component, a medium-frequency noise reduction component, and a high-frequency noise reduction component, which are sequentially arranged in the noise reduction space.
[0009] In some embodiments, the silencing space includes a first space segment and a second space segment, wherein the first space segment is located near the air inlet of the inner shell, and the second space segment is located relative to the middle part of the inner shell.
[0010] In some embodiments, the first spatial segment is provided with a low-frequency noise reduction component, a mid-frequency noise reduction component, and a high-frequency noise reduction component from the inside to the outside. The second spatial segment is provided with high-frequency noise reduction components, mid-frequency noise reduction components, and low-frequency noise reduction components in sequence from the inside to the outside.
[0011] In some embodiments, the low-frequency noise reduction component includes a low-frequency noise reduction element and a cavity, wherein the low-frequency noise reduction element is plywood, gypsum board, or a thin metal sheet.
[0012] In some embodiments, the high-frequency noise-absorbing component is polyurethane open-cell foam, melamine open-cell foam, or microporous perforated plate.
[0013] In some embodiments, the intermediate frequency noise reduction component is centrifugal glass wool or rock wool material.
[0014] In some embodiments, the inner wall of the inner shell is surrounded by sound-absorbing cotton, and the sound-absorbing cotton is provided with protrusions.
[0015] In some embodiments, an exhaust component is also included, which is disposed at the exhaust port of the inner housing, and the exhaust component includes an exhaust pipe, the inner wall of which is surrounded by sound-absorbing cotton.
[0016] In some embodiments, the circumferential surface of the exhaust pipe is provided with multiple air outlets.
[0017] The present invention also provides a dust collection fan, including an impeller, a motor, and a noise reduction device provided by the present invention, wherein the impeller and the motor are disposed within the noise reduction device.
[0018] The noise reduction device using the above-described technical solution of this utility model has the following effects: The noise reduction device provided by this invention forms a sound-absorbing space between the inner shell and the outer shell, and sequentially arranges low-frequency sound-absorbing components, mid-frequency sound-absorbing components, and high-frequency sound-absorbing components within this space, causing noise to undergo gradual attenuation along its propagation path. Compared with traditional single-layer shell structures, this invention can target and process wide-band noise, avoiding the problem that a single material can only correspond to a local frequency band, and significantly improving the overall noise reduction capability.
[0019] Because the noise-absorbing components of different frequency bands are arranged in a specific order, this invention can establish an effective acoustic barrier chain based on the actual characteristics of noise propagation from the inside out, thus improving the shortcomings of traditional double-shell structures, which are prone to cavity resonance and insufficient low-frequency sound insulation due to the fixed sandwich structure and hollow cavity. Noise is weakened by frequency division when passing through the noise-absorbing space, thereby achieving a more balanced noise reduction effect.
[0020] The structure of this invention achieves significant noise reduction without affecting the air intake and exhaust efficiency of the fan. The arrangement of the inner and outer shells still maintains the compact form of the dust collection fan, which can be directly adapted within the existing fan structure dimensions, and has good engineering feasibility.
[0021] Other features and advantages of this invention will be described in detail in the following detailed description section. Attached Figure Description
[0022] Figure 1 This is a structural schematic diagram of the noise reduction device of this utility model.
[0023] Explanation of reference numerals in the attached figures 1-Inner shell; 2-Outer shell; 3-First space section; 4-Second space section; 5-Sound-absorbing cotton; 6-Elastic connecting component. Detailed Implementation
[0024] The specific embodiments of this utility model are described in detail below. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of this utility model.
[0025] In this utility model, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the orientation in the assembled and used state. "Inner" and "outer" refer to the inner and outer sides relative to the outline of each component itself.
[0026] I. Overall Structure (See Appendix) Figure 1 ) The noise reduction device mainly comprises an inner shell 1, an outer shell 2, and the silencing space formed between them. The inner shell 1 serves as the core mounting cavity, housing functional components such as the impeller, motor, intake structure, and exhaust structure; all these noise-generating components are located inside the inner shell 1. The outer shell 2 is fitted over the inner shell 1, forming a continuous, enveloping interlayer region. This region constitutes the device's silencing space, used to attenuate aerodynamic, electromagnetic, and mechanical noise generated during operation. In other words, the impeller, motor, intake structure, and exhaust structure are all arranged inside the inner shell 1, while the silencing space between the outer shell 2 and the inner shell 1 surrounds these noise sources in a covering manner, thereby attenuating and isolating the sound energy they generate.
[0027] The anechoic space contains multiple layers of anechoic components with different functions, including low-frequency, mid-frequency, and high-frequency anechoic components. These components are arranged in a fixed order along the thickness of the shell, forming a composite acoustic structure. "Arranged in sequence" here means that the three types of materials are arranged in a layered structure, but it does not require a fixed order from the inside to the outside or from the outside to the inside. For example, in one structure, the anechoic space can have the high-frequency, mid-frequency, and low-frequency anechoic components arranged sequentially from the side closest to the inner shell 1; in another structure, the low-frequency, mid-frequency, and high-frequency anechoic components can be arranged sequentially from the inside to the outside. This sequential arrangement allows sound waves of different frequency bands to pass through the corresponding acoustic structures in sequence during transmission, thereby achieving a better broadband attenuation effect.
[0028] To better match the noise reduction device with the noise characteristics of different locations on the fan, this embodiment considers the silencing space as comprising two functional areas: the first is a first space segment 3 located near the air inlet, primarily targeting aerodynamic noise generated by impeller rotation; the second is a second space segment 4 located in the middle of the device, corresponding to electromagnetic and mechanical noise generated by motor operation. Since the dominant noise frequency bands in the two areas are different, different arrangements of silencing components can be used in the two space segments. For example, in the first space segment 3, low-frequency, mid-frequency, and high-frequency silencing components can be arranged sequentially from the inside out to address the strong low-frequency energy at the air inlet; while the second space segment 4 can adopt the opposite arrangement, with high-frequency, mid-frequency, and low-frequency silencing components arranged sequentially from the inside out to adapt to the acoustic environment where the motor section has more high-frequency noise components. Through this regionalized arrangement, this embodiment can achieve targeted absorption and isolation of noise at different frequency bands within the same structure.
[0029] In a further structural design, the inner wall of the inner shell 1 can be lined with sound-absorbing cotton 5. The surface of the sound-absorbing cotton 5 can form a raised structure to improve the scattering and reflection path of sound waves after they are incident, thereby improving the sound absorption efficiency. At the same time, the device can be equipped with an exhaust component, such as an exhaust pipe, at the exhaust port of the inner shell 1, and the inner wall of the exhaust pipe can be lined with sound-absorbing cotton 5 to reduce exhaust noise. Multiple air outlets can also be formed on the side wall of the exhaust pipe to allow the airflow to diffuse through multiple channels, which is beneficial for dispersing local exhaust noise peaks.
[0030] In addition, to ensure the stability of the noise reduction space and reduce solid-borne sound transmission, this embodiment can use elastic materials to support and fix the inner shell 1 and the outer shell 2, so that their relative positions are consistent, while reducing the structural vibration coupling between the inner shell 1 and the outer shell 2, and further improving the overall noise reduction performance.
[0031] In summary, this embodiment constructs a surround-type noise reduction space through a double-layer shell and introduces a multi-band composite material layer within this space, thereby achieving comprehensive suppression of multiple noise sources of the dust collection fan, enabling the device to have both good structural stability and wideband noise reduction capability.
[0032] II. Inner and outer shells and soundproofing space The noise reduction device in this embodiment is based on a double-shell structure, consisting of an inner shell 1 located inside and an outer shell 2 fitted outside it. The inner shell 1 forms the core working cavity of the fan, which is used to house key components such as the impeller, motor, air intake assembly, and exhaust assembly; the outer shell 2 structurally covers the inner shell 1, forming a continuous, surrounding sandwich area between the two. This area is the silencing space, which is used to accommodate various silencing components and achieve multi-level attenuation of sound waves.
[0033] Furthermore, the inner shell 1 and the outer shell 2 are connected by several elastic connectors 6. These elastic connectors 6 not only ensure the relative positional stability between the two shells but also provide structural vibration isolation, preventing vibrations generated by the inner shell 1 during impeller and motor operation from being directly transmitted to the outer shell 2. This flexible connection method maintains a uniform and stable sound-absorbing space between the two shells, further suppressing structural sound transmission and improving the overall noise reduction effect.
[0034] 2.1 Inner Casing 1: The inner casing 1 can be made of metal materials such as aluminum alloy and steel plate, or engineering plastics such as reinforced polypropylene. The material can be flexibly selected according to the application environment and cost requirements of the fan. As the direct load-bearing structure of the impeller and motor, the inner casing 1 needs to have high strength and rigidity to ensure stable support of the internal components during the operation of the fan and to resist vibrations caused by high-speed rotation and airflow disturbance.
[0035] 2.2 Outer Shell 2: The outer shell 2 can also be made of metal or engineering plastic materials, and its material thickness is usually slightly larger than that of the inner shell 1 to further improve the overall rigidity and sound insulation performance. The outer shell 2 is fitted and fixed to the outside of the inner shell 1 through an appropriate connecting structure, so that a structurally stable and dimensionally controllable surrounding sandwich area is formed between the two, providing a spatial basis for the subsequent arrangement of sound-absorbing materials.
[0036] 2.3 Silencing Space: The silencer space is formed by the gap between the inner shell 1 and the outer shell 2, continuously extending along the fan axis and covering the fan's intake section, motor section, and part of the exhaust section. This space is usually ring-shaped, and its thickness can be designed within the range of approximately 5 to 50 mm, depending on the noise reduction intensity and overall machine volume requirements. Through this surrounding layout, the silencer space can attenuate noise radiated from different directions without increasing the complexity of the internal airflow path.
[0037] 2.4 Acoustic Characteristics and Segmentation of the Silencing Space: Noise sources at different locations exhibit significant differences. The area near the air intake is mainly affected by aerodynamic disturbances, with noise components primarily consisting of low and low-mid frequencies; while the area near the motor is mainly composed of mechanical and electromagnetic noise generated by the motor's operation, predominantly mid-high and high frequencies. Based on this acoustic distribution characteristic, the front section of the silencing space is more suitable for using a larger spatial thickness to improve the sound insulation capability for low-frequency sounds; while even if the rear section has a thinner space, high-frequency energy can be rapidly dissipated through the proper configuration of sound-absorbing materials.
[0038] Therefore, to adapt to the noise characteristics of different locations, this embodiment divides the silencing space into two segments: a first segment 3 near the air inlet and a second segment 4 located near the middle of the inner shell 1. Different noise reduction structures and material arrangements are used in the two segments. The specific structures and configurations of the first segment 3 and the second segment 4 will be described in detail later.
[0039] III. First Space Segment 3 The first spatial section 3 is located in the area surrounding the air inlet of the inner shell 1, and is the front part of the entire silencing space. This area is adjacent to the air inlet section of the fan and mainly faces the aerodynamic noise generated when the airflow is drawn in by the impeller, including pulsating noise, eddy noise, and broadband noise generated by airflow impacting structural components in the low to mid-low frequency range. In order to effectively reduce this type of low-frequency noise with high energy and strong penetration, this embodiment adopts a large spatial thickness in the first spatial section 3 and combines different types of silencing components to construct a front-end noise reduction structure with multiple sound attenuation mechanisms.
[0040] The thickness of the sound-absorbing space in the first spatial segment 3 can be set to be larger than that in the second spatial segment 4. A larger spatial thickness can form a more effective sound blocking path and facilitate multiple reflections and energy dissipation of low-frequency sound waves within the cavity. At the same time, it provides sufficient structural margin for arranging sound-absorbing components with low-frequency response capabilities.
[0041] Arrangement of noise reduction components: In the first space segment 3, the noise reduction components can be arranged in sequence from the inside to the outside, including low-frequency noise reduction components, mid-frequency noise reduction components and high-frequency noise reduction components.
[0042] The low-frequency noise reduction component is located closest to the inner shell 1. It forms a low-frequency sound damping and vibration isolation system by combining the cavity structure with the mass plate (such as plywood, gypsum board, or thin metal plate), which effectively attenuates long-wavelength noise.
[0043] The mid-frequency noise reduction component is located in the middle area and can be made of fiber materials such as centrifugal glass wool and rock wool. It absorbs mid-frequency sound energy through inter-fiber friction and structural damping. The high-frequency noise reduction component is located on the outermost side, and uses polyurethane open-cell foam, melamine foam or microporous perforated plate to quickly absorb high-frequency sound, further reducing the leakage of residual sound waves.
[0044] This progressive arrangement from the inside out can form a multi-level damping structure that conforms to the sound wave propagation path, so that noise in different frequency bands is attenuated layer by layer during propagation, resulting in a significant overall noise reduction effect.
[0045] By employing the aforementioned thickness design and component arrangement within the first spatial section 3, the device's ability to suppress low-frequency and mid-low-frequency noise in the air intake section can be effectively improved, ensuring that the difficult-to-attenuate low-frequency energy is sufficiently reduced before entering the outer casing 2. Simultaneously, mid-frequency and high-frequency noise can be gradually absorbed within the multi-layered sound-absorbing system of this region, thereby reducing the burden on the subsequent noise reduction task in the second spatial section 4 and enhancing the overall acoustic performance of the entire device.
[0046] IV. Second Space Segment 4 The second spatial segment 4 is located in the outer region of the motor segment, and its main function is to absorb and attenuate the mid-to-high frequency and high-frequency noise generated during motor operation. The noise sources of the motor segment include electromagnetic noise, air noise generated by stator-rotor air gap pulsation, and high-frequency mechanical noise transmitted from the shaft and support structure. These noises are high in frequency, short in wavelength, and concentrated in energy, and are more likely to propagate through solids via the shell structure.
[0047] The silencing space of the second spatial segment 4 can be thinner than that of the first spatial segment 3. By reducing the cavity size, the absorption efficiency of high-frequency noise can be improved, while avoiding structural redundancy or ineffective use due to excessive space. Fiber sound-absorbing materials, microporous sound-absorbing layers, or damping composite materials can be arranged on the outer side of the inner shell 1 and the inner side of the outer shell 2 inside the second spatial segment 4. This causes high-frequency sound waves to undergo rapid multiple reflections and frictional losses after entering the interlayer, thereby significantly reducing sound energy.
[0048] Arrangement of noise reduction components: In the second space section 4, high-frequency noise reduction components, mid-frequency noise reduction components, and low-frequency noise reduction components are arranged sequentially from the inside to the outside.
[0049] The high-frequency noise reduction component is located on the side closest to the inner shell 1. It can be made of high-frequency sound-absorbing materials such as polyurethane open-cell foam, melamine open-cell foam or microporous perforated plate. By utilizing its high efficiency in absorbing short-wavelength sound waves, the high-frequency noise entering the interlayer is significantly attenuated in the initial stage.
[0050] The mid-frequency noise reduction component is located in the middle area and can be made of fiber materials such as centrifugal glass wool and rock wool. It absorbs mid-frequency sound energy through inter-fiber friction and structural damping. The low-frequency noise reduction component is located on the outermost side and includes a low-frequency noise reduction element and a cavity structure formed in conjunction with it. The low-frequency noise reduction element can be made of plywood, gypsum board, or thin metal plate. The resonance effect between the mass plate and the cavity weakens some of the low-frequency noise that propagates deep into the cavity.
[0051] The second spatial segment 4 can form a rapid absorption path for high-frequency and mid-to-high-frequency noise generated by the motor segment, while compensating for the attenuation of low-frequency components that may penetrate the first two layers. This allows the entire sandwich structure to achieve efficient energy dissipation and broadband noise reduction for high-frequency noise in this segment. It complements the arrangement of the first spatial segment 3, which faces the low-frequency noise of the air intake segment, so that the entire double-shell silencing space constitutes a comprehensive noise reduction system covering the entire frequency band in the axial direction.
[0052] V. Low-frequency, mid-frequency, and high-frequency noise reduction components Silencing components can be categorized into low-frequency, mid-frequency, and high-frequency components based on the target noise frequency band. These components differ significantly in material structure, working mechanism, and applicable frequency band, and can be combined and arranged according to the noise characteristics of different locations on the fan.
[0053] 5.1 Low-frequency noise reduction components: Low-frequency noise has a long wavelength and strong penetrating power, and generally needs to be attenuated by a mass-spring-cavity system composed of a mass plate and a cavity structure. Low-frequency noise reduction components can use plywood, gypsum board, or thin metal sheets as low-frequency noise reduction parts, forming a matching cavity with the surrounding space, thereby utilizing the vibration of the board to absorb low-frequency sound energy or generate local resonance to weaken specific low-frequency noise.
[0054] 5.2 Mid-Frequency Noise Reduction Components: Mid-frequency noise is mainly dissipated through porous fibrous materials. Commonly used materials include centrifugal glass wool, rock wool, and other fibrous sound-absorbing media. The numerous micropores within these materials generate friction and viscous loss as sound waves penetrate, converting sound energy into heat energy. These components have moderate density and a wide absorption range, making them versatile sound-absorbing materials between the motor section and the air intake section.
[0055] 5.3 High-Frequency Noise Absorption Components: High-frequency noise has a short wavelength and is easily absorbed quickly by porous structures, making open-cell foam or micro-perforated panels suitable. Typical materials include polyurethane open-cell foam, melamine open-cell foam, and micro-perforated panels with micro-perforations and back cavity structures. The fine pores in these materials can generate a strong viscous damping effect on high-frequency sound waves, achieving rapid energy attenuation.
[0056] VI. Sound-absorbing structure inside the inner shell 1 To further reduce the mid-to-high frequency noise generated during the operation of the impeller and motor, this embodiment provides a layer of sound-absorbing cotton 5 (attached) circumferentially on the inner wall of the inner casing 1. Figure 1 (Not visible in the middle). This layer of sound-absorbing cotton 5 is tightly fitted to the inner shell 1, forming a surrounding sound-absorbing lining structure, which can absorb and attenuate sound waves as soon as they enter the shell, reducing the outward propagation of sound energy.
[0057] To improve sound absorption efficiency, the surface of the sound-absorbing cotton 5 is provided with a uniformly distributed protrusion structure. The presence of protrusions can significantly increase the incident path of sound waves, causing sound waves to undergo multiple reflections on the surface of the microstructure, thereby enhancing the friction and viscous loss within the material. At the same time, the protrusions can also form microcavity structures of different depths locally, enabling the sound-absorbing material to effectively deal with noise over a wider frequency range, especially achieving a higher sound absorption coefficient in the common mid-to-high frequency range.
[0058] By arranging sound-absorbing cotton 5 with protrusions on the inner wall of the inner shell 1, the internal noise can be pre-absorbed, reducing noise leakage from the source, and forming a synergistic effect with the external multi-layer sound-absorbing structure to improve the overall noise reduction effect.
[0059] VII. Noise Reduction Structure for Exhaust Components The noise reduction device in this embodiment also includes an exhaust component disposed at the exhaust port of the inner housing 1, which is used to guide and reduce the noise of the high-speed airflow discharged by the fan. The exhaust component is mainly composed of an exhaust pipe, which is connected to the exhaust port of the inner housing 1, so that the internal airflow can be smoothly discharged after passing through the impeller and the motor.
[0060] To reduce flow noise and pulsating noise during exhaust, a layer of sound-absorbing cotton 5 is laid circumferentially on the inner wall of the exhaust pipe. This sound-absorbing cotton 5 fits tightly against the inner wall, forming a surrounding sound-absorbing channel. When high-speed airflow passes through the exhaust pipe, the mid-to-high frequency noise carried by the airflow comes into full contact with the surface of the sound-absorbing cotton 5, causing the sound waves to attenuate due to friction within the fiber structure, thus dissipating energy. This structure has a significant absorption effect on typical mid-to-high frequency noise in the exhaust section.
[0061] In some embodiments, the exhaust duct has multiple vent holes on its circumference. These vent holes can guide some of the airflow to the outside during exhaust, buffering and dispersing pressure fluctuations inside the duct, thereby further suppressing transient peaks in exhaust noise. Multiple vent holes can also create additional turbulence paths during airflow diffusion, causing some sound waves to be reflected and lost multiple times around the vent holes, improving overall noise reduction efficiency.
[0062] Through the above structure, the exhaust component not only ensures the smoothness of the exhaust flow channel, but also constructs an independent sound absorption and diffusion attenuation mechanism on the exhaust path, thereby further reducing the noise output at the tail end of the fan and improving the overall noise reduction performance.
[0063] VIII. Overall Structure of the Dust Collection Fan The dust collection fan in this embodiment is composed of an impeller, a motor, and the aforementioned noise reduction device. Both the impeller and motor are installed inside the noise reduction device, creating a compact, integrated layout between the fan's power unit and the multi-stage sound-absorbing structure. Through this combination, the fan achieves efficient airflow drive while fully utilizing the multi-layered sound absorption and insulation structure of the noise reduction device, significantly reducing operating noise.
[0064] The core power components of a dust collection fan include an impeller and a motor. The impeller and motor are connected by a shaft, and the motor drives their rotation to generate a stable and strong airflow. The impeller is typically located near the front inlet of the inner casing 1 to draw in outside air; the motor is located at the rear end of the impeller, providing continuous driving force. Depending on the specific application requirements, the impeller can adopt a radial or forward-curved structure to balance airflow and pressure performance.
[0065] The impeller and motor are both housed within the inner casing 1 of the noise reduction device. The inner casing 1 constitutes the main working cavity of the fan and together with the outer casing 2, forms a surrounding noise reduction space. Low-frequency noise reduction components, mid-frequency noise reduction components, and high-frequency noise reduction components are arranged within the noise reduction space, enabling the noise generated by the fan in different frequency bands during operation to be attenuated in stages, thereby significantly reducing the overall noise output of the machine.
[0066] The air intake direction of the fan is usually located at the front end of the noise reduction device. Air enters the inner casing 1 through the air intake port, is accelerated by the impeller and pushed to the exhaust port at the rear end, and then discharged through the exhaust component. The exhaust component includes an exhaust pipe, the inner wall of which is surrounded by sound-absorbing cotton 5, and in some embodiments, it is provided with multiple air outlets to further absorb and diffuse the airflow noise at the exhaust end.
[0067] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.
[0068] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, this utility model will not describe the various possible combinations separately.
[0069] Furthermore, various different embodiments of this utility model can be combined in any way, as long as they do not violate the spirit of this utility model, they should also be regarded as the content disclosed by this utility model.
Claims
1. A noise reduction device, characterized in that, include: Inner shell (1); The outer shell (2) is fitted onto the outside of the inner shell (1), and a sound-absorbing space is formed between the outer shell (2) and the inner shell (1); The noise reduction component includes a low-frequency noise reduction component, a medium-frequency noise reduction component, and a high-frequency noise reduction component, which are sequentially arranged in the noise reduction space.
2. The noise reduction device according to claim 1, characterized in that, The silencing space includes a first space segment (3) and a second space segment (4). The first space segment (3) is located near the air inlet of the inner shell (1), and the second space segment (4) is located relative to the middle part of the inner shell (1).
3. The noise reduction device according to claim 2, characterized in that, The first spatial segment (3) is provided with a low-frequency noise reduction component, a mid-frequency noise reduction component and a high-frequency noise reduction component from the inside to the outside; The second space segment (4) is provided with a high-frequency noise reduction component, a medium-frequency noise reduction component, and a low-frequency noise reduction component in sequence from the inside to the outside.
4. The noise reduction device according to claim 1, characterized in that, The low-frequency noise reduction component includes a low-frequency noise reduction element and a cavity, wherein the low-frequency noise reduction element is plywood, gypsum board, or thin metal sheet.
5. A noise reduction device according to claim 1, characterized in that, The high-frequency noise reduction component is polyurethane open-cell foam, melamine open-cell foam, or microporous perforated plate.
6. The noise reduction device according to claim 1, characterized in that, The intermediate frequency noise reduction component is made of centrifugal glass wool or rock wool.
7. The noise reduction device according to claim 1, characterized in that, The inner wall of the inner shell (1) is surrounded by sound-absorbing cotton (5), and the sound-absorbing cotton (5) is provided with protrusions.
8. A noise reduction device according to any one of claims 1 to 7, characterized in that, It also includes an exhaust component, which is disposed at the exhaust port of the inner housing (1), and the exhaust component includes an exhaust pipe, the inner wall of which is surrounded by sound-absorbing cotton (5).
9. A noise reduction device according to claim 8, characterized in that, The exhaust pipe has multiple air outlets on its circumference.
10. A dust collection fan, characterized in that, It includes an impeller, a motor, and a noise reduction device according to any one of claims 1-9, wherein the impeller and the motor are disposed within the noise reduction device.