Low-noise axial flow fan

Abstract

The low-noise axial flow fan comprises a machine shell, a mounting base, an impeller and a driving mechanism, the mounting base is fixed in the machine shell, the mounting base is connected with the driving mechanism, and the driving mechanism is connected with the impeller; the shell is connected with a flow guide cover, and a plurality of flow guide strips arranged along an involute angle are arranged on the inner wall of the flow guide cover; the impeller comprises a hub and blades, the blades are provided with a plurality of sound absorption holes, and cutting teeth are arranged at the outer ends of the blades. The involute type flow guide strips are arranged, so that the impact of airflow on the inner wall of the fan is reduced, and the impact noise is effectively reduced.

Description

Technical Field

[0001] This utility model belongs to the field of fans, specifically relating to a low-noise axial flow fan. Background Technology

[0002] Axial flow fans are a common type of fan. The conventional structure of an axial flow fan consists of a mounting base fixed inside the casing, a motor connected to the mounting base, and an impeller connected to the motor. However, the motor, impeller, and mounting base are all rigidly connected, and mechanical vibration during operation will generate significant noise. Furthermore, when the fan converges airflow, the vibration generated by the high-speed movement of the airflow and the impact with the impeller and casing will also generate significant noise, causing sound pollution and potentially affecting workers' hearing. Therefore, there is an urgent need to develop a low-noise axial flow fan. Utility Model Content

[0003] To address the aforementioned issues, this application proposes a low-noise axial flow fan, comprising a casing, a mounting base, an impeller, and a drive mechanism. The mounting base is fixed inside the casing, the drive mechanism is connected to the mounting base, and the impeller is connected to the drive mechanism.

[0004] The housing is connected to a flow guide, and the inner wall of the flow guide is provided with multiple flow guide strips arranged along an involute angle;

[0005] The impeller includes a hub and blades. The blades are provided with multiple sound-absorbing holes and cutting teeth at the outer ends of the blades.

[0006] The involute design of the airflow guides the airflow forward in a spiral motion, reducing direct impact with the casing and airflow shield, thereby reducing the noise generated by the impact. The cutting teeth are designed to cut off the vortices generated by the airflow during the rotation of the blades, further reducing the vibration noise during airflow. The sound-absorbing holes use the porous principle to absorb sound waves of a certain frequency.

[0007] Furthermore, the flow guide includes a sound-absorbing layer, a filling layer, and an outer shell layer arranged sequentially from the inside out, with flow guide strips disposed inside the sound-absorbing layer.

[0008] Furthermore, the sound-absorbing layer is equipped with multiple Helmholtz resonant cavities, the filling layer is a sound-absorbing sponge layer, and the outer shell layer is a metal layer; the air guide is also equipped with Helmholtz resonant cavities for sound absorption. The sound first enters the Helmholtz resonant cavity for initial sound absorption, and then the sound-absorbing sponge is used for further sound absorption, which reduces the noise generated by the airflow itself to the greatest extent.

[0009] Furthermore, the sound-absorbing holes are designed with a honeycomb structure, and the opening direction of the sound-absorbing holes is adapted to the curvature of the blades.

[0010] Furthermore, a porous layer of alumina-carbon nanotube composite is sprayed onto the surface of the blade, and the porous layer covers the sound-absorbing holes.

[0011] The honeycomb structure and porous layer form a series resonator to absorb noise through resonance. At the same time, the porous layer further expands the frequency of noise absorption, thereby converting sound waves into heat energy through the high thermal conductivity of carbon nanotubes and dissipating it quickly, forming a multi-band sound absorption effect.

[0012] Furthermore, the mounting base integrates an elastic layer, a damping layer, and a support layer sequentially from the outside to the inside; the elastic layer uses elastic structures such as silicone or rubber layers, and the damping layer can dissipate the energy of vibration through friction or deformation.

[0013] Furthermore, the damping layer is a polyurethane-carbon fiber composite sheet, which converts mechanical energy into heat energy through the friction of polyurethane molecular chains, and the carbon fiber can enhance the damping efficiency; this configuration effectively alleviates mechanical vibration between the motor and the mounting base.

[0014] Furthermore, a damping washer is provided at the connection between the blade and the hub. The damping washer is composited with piezoelectric fibers, which are connected to wires. The wires are connected to a contactor fixed to the hub. The mechanical vibration of the blade during rotation is transmitted to the piezoelectric fibers, causing the crystals inside the piezoelectric fibers to change and generate voltage, converting mechanical energy into electrical energy and consuming it.

[0015] Furthermore, the outer layer of the damping washer is a rubber layer, and the inner layer is a rigid layer. The rubber layer and the rigid layer are nested together. The rubber layer has piezoelectric fibers on the contact surface with the blade and the contact surface with the hub. Large amplitude vibrations can be effectively absorbed by the highly elastic structure such as rubber. The remaining vibrations generate voltage through the change of crystals inside the piezoelectric fibers, which is converted into electrical energy and consumed.

[0016] Furthermore, the outermost end of the guide strip is also provided with stepped cutting teeth to cut the vortices generated by the airflow during movement.

[0017] The beneficial effects of this utility model are as follows:

[0018] (1) Set an involute guide strip to reduce the impact of airflow on the inner wall of the fan and effectively reduce impact noise.

[0019] (2) Cutting teeth are set at the tip of the blade to effectively cut off the vortex in the airflow and reduce the noise generated by the vortex when the airflow flows.

[0020] (3) The blades are equipped with sound-absorbing holes and the shroud is equipped with a sound-absorbing layer. The porous structure is used for resonance sound absorption to reduce the noise generated by the vibration of the airflow itself.

[0021] (4) Set up an elastic damping base to reduce the noise generated by the mechanical vibration of the motor and the mounting base. Attached Figure Description

[0022] The accompanying drawings, which are provided to further illustrate this application and form part of this application, illustrate exemplary embodiments of this application and are used to explain this application, but do not constitute an undue limitation of this application.

[0023] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present utility model;

[0024] Figure 2 This is a schematic diagram of the impeller structure according to an embodiment of the present utility model;

[0025] In the attached diagram: 1-casing, 2-mounting base, 3-impeller, 31-hub, 32-blade, 321-sound-absorbing hole, 322-cutting tooth, 33-shock-absorbing washer, 4-drive mechanism, 5-guide shroud, 51-guide strip, 52-Helmholtz resonant cavity. Detailed Implementation

[0026] To more clearly illustrate the overall concept of this application, a detailed explanation is provided below with reference to the accompanying drawings.

[0027] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of this application is not limited to the specific embodiments disclosed below.

[0028] Furthermore, it should be understood in the description of this application that the terms "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0029] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication 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 invention according to the specific circumstances.

[0030] In this application, unless otherwise expressly specified and limited, the "above" or "below" of the second feature can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. In the description of this specification, references to terms such as "an embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples.

[0031] like Figure 1-2 As shown, a low-noise axial flow fan includes a housing 1, a mounting base 2, an impeller 3, and a drive mechanism 4. The mounting base 2 is fixed inside the housing 1, the drive mechanism 4 is connected to the mounting base 2, and the impeller 3 is connected to the drive mechanism 4.

[0032] The housing 1 is connected to a flow guide 5, and the inner wall of the flow guide 5 is provided with multiple flow guide strips 51 arranged along an involute angle;

[0033] The impeller 3 includes a hub 31 and blades 32. The blades 32 are provided with multiple sound-absorbing holes 321 and cutting teeth 322 are provided at the outer end of the blades 32.

[0034] The involute shape of the guide bar 51 guides the airflow forward in a spiral, reducing direct impact with the casing 1 and the guide shroud 5, thereby reducing the noise generated by the impact. The cutting teeth 322 are designed to cut off the vortices generated by the airflow during the rotation of the blades 32, further reducing the vibration noise during airflow. The sound-absorbing holes 321 absorb sound waves of a certain frequency using the principle of porous structure. The blades 32 and the guide shroud 5 work together to significantly reduce the noise during the operation of the fan.

[0035] In one specific embodiment, the flow guide 5 includes a sound-absorbing layer, a filling layer, and an outer shell layer arranged sequentially from the inside out, with the flow guide strip 51 disposed inside the sound-absorbing layer.

[0036] In one specific embodiment, the sound-absorbing layer is provided with multiple Helmholtz resonant cavities 52, the filling layer is a sound-absorbing sponge layer, and the outer shell layer is a metal layer; the flow guide shroud 5 is also provided with Helmholtz resonant cavities 52 for sound absorption. The sound first enters the Helmholtz resonant cavity 52 for initial sound absorption, and then the sound-absorbing sponge is used for further sound absorption, thereby reducing the noise generated by the airflow itself to the greatest extent.

[0037] In one specific embodiment, the sound-absorbing hole 321 is configured as a honeycomb structure, and the opening direction of the sound-absorbing hole 321 is adapted to the curvature of the blade 32.

[0038] In one specific embodiment, the surface of the blade 32 is coated with a porous layer of alumina-carbon nanotube composite, and the porous layer covers the sound-absorbing holes 321.

[0039] The honeycomb structure and porous layer form a series resonator to absorb noise through resonance. At the same time, the porous layer further expands the frequency of noise absorption, thereby converting sound waves into heat energy through the high thermal conductivity of carbon nanotubes and dissipating it quickly, forming a multi-band sound absorption effect.

[0040] In one specific embodiment, the mounting base 2 is integrated with an elastic layer, a damping layer and a support layer from the outside to the inside; the elastic layer uses an elastic structure such as a silicone layer or a rubber layer, and the damping layer can dissipate the energy of vibration through friction or deformation.

[0041] In one specific embodiment, the damping layer is a polyurethane-carbon fiber composite sheet, which converts mechanical energy into heat energy through the friction of polyurethane molecular chains, and the carbon fiber can enhance the damping efficiency; this arrangement effectively alleviates the mechanical vibration between the motor and the mounting base 2.

[0042] In one specific embodiment, a damping washer 33 is provided at the connection between the blade 32 and the hub 31. The damping washer 33 is composite with piezoelectric fibers. The piezoelectric fibers are connected to wires, and the wires are connected to a contactor fixed to the hub 31. The mechanical vibration of the blade 32 when it rotates is transmitted to the piezoelectric fibers, causing the crystals inside the piezoelectric fibers to change and generate voltage, converting mechanical energy into electrical energy and consuming it.

[0043] In one specific embodiment, the outer layer of the damping washer 33 is a rubber layer, and the inner layer is a rigid layer. The rubber layer and the rigid layer are nested together. The rubber layer has piezoelectric fibers on the contact surface with the blade 32 and the contact surface with the hub 31. Large amplitude vibrations can be effectively absorbed by highly elastic structures such as rubber. The remaining vibrations generate voltage through changes in the internal crystals of the piezoelectric fibers, which are then converted into electrical energy and consumed.

[0044] In one specific embodiment, the outermost end of the guide bar 51 is also provided with stepped cutting teeth 322, which are used to cut the vortex generated by the airflow during movement.

[0045] For any parts not mentioned in this application, existing technologies may be used or referenced.

[0046] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0047] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A low-noise axial flow fan, comprising a casing, a mounting base, an impeller, and a drive mechanism, characterized in that, A mounting base is fixed inside the housing, and a drive mechanism is connected to the mounting base. An impeller is connected to the drive mechanism. The housing is connected to a flow guide shroud, and the inner wall of the flow guide shroud is provided with a plurality of flow guide strips arranged along an involute angle; The impeller includes a hub and blades. The blades are provided with multiple sound-absorbing holes, and the outer ends of the blades are provided with cutting teeth.

2. The low-noise axial flow fan according to claim 1, characterized in that, The air guide cover includes a sound-absorbing layer, a filling layer, and an outer shell layer arranged sequentially from the inside out, and the air guide strip is located inside the sound-absorbing layer.

3. A low-noise axial flow fan according to claim 2, characterized in that, The sound-absorbing layer is provided with multiple Helmholtz resonant cavities, the filling layer is a sound-absorbing sponge layer, and the outer shell layer is a metal layer.

4. A low-noise axial flow fan according to claim 1, characterized in that, The sound-absorbing holes are configured with a honeycomb structure, and the opening direction of the sound-absorbing holes is adapted to the curvature of the blade.

5. A low-noise axial flow fan according to claim 4, characterized in that, The blade surface is coated with a porous layer of alumina-carbon nanotube composite, and the porous layer covers the sound-absorbing holes.

6. A low-noise axial flow fan according to claim 1, characterized in that, The mounting base integrates an elastic layer, a damping layer, and a support layer from the outside to the inside.

7. A low-noise axial flow fan according to claim 6, characterized in that, The damping layer is a polyurethane-carbon fiber composite sheet.

8. A low-noise axial flow fan according to claim 1, characterized in that, A shock-absorbing washer is provided at the connection between the blade and the hub. The shock-absorbing washer is composited with piezoelectric fibers. The piezoelectric fibers are connected to wires. The wires are connected to a contactor fixed to the hub.

9. A low-noise axial flow fan according to claim 8, characterized in that, The outer layer of the shock-absorbing washer is a rubber layer, and the inner layer is a rigid layer. The rubber layer and the rigid layer are nested together. The rubber layer has piezoelectric fibers on the contact surface with the blade and the contact surface with the hub.

10. A low-noise axial flow fan according to claim 1, characterized in that, The outermost end of the guide strip is also provided with stepped cutting teeth.

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