Double-layer porous air guide and noise reduction type axial flow fan
By introducing silencers and silencer holes into the axial flow fan to reduce aerodynamic noise, and using composite buffer blocks to reduce vibration noise, the aerodynamic and vibration noise problems of the axial flow fan are solved, achieving noise reduction effect and cost optimization.
Patent Information
- Application Number
- CN202511017304.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-23
- Publication Date
- 2025-10-03
AI Technical Summary
Existing axial flow fans have problems with aerodynamic noise and vibration noise during operation. Aerodynamic noise is directly transmitted and radiated through the high-frequency noise formed by the vortex on the trailing edge of the blade. Vibration noise is not effectively reduced by rubber pads and is prone to aging.
A double-layer porous air-guiding noise-reducing axial flow fan is used. A silencer and silencer holes are set in the air duct to reduce aerodynamic noise. A composite buffer block is used between the wind cover and the air duct to reduce vibration noise. The silencer and the air duct are connected by an inlay structure, eliminating screws and other accessories, and the design of silencer holes and buffer blocks is used to reduce noise.
It effectively reduces aerodynamic noise and vibration noise, reduces assembly costs, and improves vibration and impact resistance. The design of silencer holes and buffer blocks can effectively suppress eddy current noise and absorb vibration impact force.
Smart Images
Figure CN120739749A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of fans, and in particular to a double-layer porous air-guiding and noise-reducing axial flow fan. Background Art
[0002] Axial fans are prone to aerodynamic noise and vibration noise during operation. To address aerodynamic noise, the market currently uses improvements to the impeller blades to avoid strong gas turbulence, thereby reducing aerodynamic noise. However, when the airflow passes through the blades, periodic eddies will still form at the trailing edge of the blades. This eddy will generate high-frequency aerodynamic noise. The aerodynamic noise is directly transmitted to the air guide tube and collides with the air guide tube, forming reflection and superposition of sound waves, and then radiating directly outward, which cannot absorb or reduce aerodynamic noise. To address vibration noise, rubber pads are generally set for vibration reduction. However, rubber pads are prone to hardening due to aging after long-term use and cannot play a good vibration reduction role. Summary of the Invention
[0003] The object of the present invention is to provide a double-layer porous air-guiding noise-reducing axial flow fan which can reduce both aerodynamic noise and vibration noise.
[0004] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a double-layer porous air-guiding noise-reducing axial flow fan, comprising: a wind cover, an air guide tube, an impeller, a bracket and a motor, a center hole is opened at the center position of the wind cover, the bracket is fixed on the wind cover in a circle, the inner ends of the brackets converge at the center hole, the motor is located in the center hole and is connected to the inner ends of each bracket, the impeller is fixed on the motor, the leading edge of the blades on the impeller is lower than the trailing edge, and comb teeth are provided on the trailing edge, the outer end of the bracket extends downward from the wind cover and is at the outer end of the bracket A connecting plate with a through hole is provided on it, and a number of notches are evenly distributed around the circumference of the upper edge of the air guide tube. U-shaped seats are welded in the notches, and a screw is vertically arranged in the U-shaped seat. A composite buffer block is sleeved on the screw, and the connecting plate is sleeved on the screw through the through hole and rests on the composite buffer block. A locking nut is threadedly connected to the screw, and the locking nut is screwed and rests on the connecting plate. A silencer is embedded in the air guide tube, and a cavity is left between the silencer and the air guide tube. A number of silencer holes are evenly distributed around the circumference of the silencer.
[0005] Furthermore, in the aforementioned double-layer porous air-guiding and noise-reducing axial flow fan, the ratio between the diameter d of the silencer hole and the diameter D of the impeller is: 0.004≤d / D≤0.01, the ratio between the circumferential center distance L of the silencer hole and the diameter D of the impeller is: 0.03≤L / D≤0.08, and the ratio between the axial center distance H of the silencer hole and the diameter D of the impeller is 0.0065≤H / D≤0.012.
[0006] Furthermore, the aforementioned double-layer porous air-guiding and noise-reducing axial fan, wherein the composite buffer block includes: a buffer rubber block and a buffer spring, a avoidance hole for avoiding the screw is provided at the center of the buffer rubber block, four spring countersunk holes are evenly distributed around the circumference of the buffer rubber block, a buffer spring is inserted into each of the four spring countersunk holes, the bottom of the buffer spring rests on the bottom wall stretched by the spring, and the top of the buffer spring is 1 to 1.5 mm lower than the top of the spring countersunk hole.
[0007] Furthermore, the aforementioned double-layer porous air-guiding and noise-reducing axial flow fan is provided with a lower limit groove on the bottom upper wall of the U-shaped seat, and an upper limit groove is provided on the bottom lower wall of the connecting plate, the upper side wall of the buffer rubber block is inserted into the upper limit groove, and the lower side wall of the buffer rubber block is inserted into the lower limit groove.
[0008] Furthermore, in the aforementioned double-layer porous air-guiding and noise-reducing axial fan, a T-shaped rubber sleeve is inserted into the through hole of the connecting plate, the small-diameter end of the T-shaped rubber sleeve extends into the through hole, the large-diameter end of the T-shaped rubber sleeve rests on the connecting plate, and the locking nut is screwed and rests on the large-diameter end of the T-shaped rubber sleeve.
[0009] Furthermore, the aforementioned double-layer porous air-guiding and noise-reducing axial flow fan, wherein the connection structure between the silencer and the air guide tube is as follows: an outer straight section is provided in the middle of the air guide tube, and an outward-turned inlet arc and an outlet arc are integrally extended at the upper and lower ends of the outer straight section, and the upper edge is located on the inlet arc; an inner straight section is provided in the middle of the silencer, and an outward-turned upper clamping arc and a lower clamping arc are integrally extended at the upper and lower ends of the inner straight section, and the upper clamping arc and the lower clamping arc are respectively engaged with the inlet arc and the outlet arc through their own elastic deformation, and the silencer holes are provided on the inner straight section and the lower clamping arc.
[0010] Furthermore, in the aforementioned double-layer porous air-guiding and noise-reducing axial flow fan, the thickness of the silencer is 1 to 1.5 mm, the cavity spacing between the silencer and the air-guiding tube is 0 to 5.5 mm, and the silencer holes are arranged on the inner straight section and the lower inverted arc corresponding to the cavity spacing of not less than 5 mm.
[0011] Furthermore, in the aforementioned double-layer porous air-guiding and noise-reducing axial flow fan, the trailing edge of the blade is not lower than the top of the inner straight section, and the leading edge of the blade is higher than the bottom of the inner straight section.
[0012] Furthermore, the aforementioned double-layer porous air-guiding and noise-reducing axial flow fan, wherein the wind cover includes: a plurality of grille rings with gradually increasing diameters and concentrically arranged, the innermost grille ring serves as the center hole of the wind cover, the bracket is welded to each grille ring, and two connecting rods are equally welded on the grille ring between each two adjacent brackets.
[0013] Furthermore, in the aforementioned double-layer porous air-guiding and noise-reducing axial flow fan, the distance between each two adjacent grille rings gradually increases from the inside to the outside.
[0014] The advantages of the present invention are that: a silencer with a silencer hole is arranged in the air duct to reduce aerodynamic noise, a composite buffer block is arranged between the wind cover and the air duct to reduce vibration noise, and the silencer and the air duct are connected by an embedded structure, which can not only save accessories such as screws and rivets, reduce assembly costs, but also improve vibration resistance and impact resistance. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 The invention discloses a double-layer porous air-guiding and noise-reducing axial flow fan.
[0016] Figure 2 yes Figure 1 Schematic diagram of the cross-section structure in.
[0017] Figure 3 yes Figure 2 Schematic diagram of the structure of the composite buffer block. DETAILED DESCRIPTION
[0018] The technical solution of the present invention will be further described below with reference to the accompanying drawings and preferred embodiments.
[0019] like Figures 1 to 3As shown, the double-layer porous air-guiding and noise-reducing axial flow fan of the present invention comprises: a wind cover 1, an air guide tube 2, an impeller 3, a bracket 4 and a motor 5. The middle part of the air guide tube 2 is an outer straight section 21, and the upper and lower ends of the outer straight section 21 are respectively integrally extended with an outward-turned inlet arc 22 and an outlet arc 23. An upper edge 24 is provided on the inlet arc 22, and four notches are evenly distributed on the circumference of the upper edge 24. U-shaped seats 25 are welded in the four notches. A screw 251 is vertically provided in the U-shaped seat 25, and a silencer 6 is embedded in the air guide tube 2. The middle part of the silencer 6 is an inner straight section 61. The upper and lower ends of the inner straight section 61 are integrally extended with an outward-turned upper clamping arc 62 and a lower clamping arc 63. The upper clamping arc 62 and the lower clamping arc 63 are respectively engaged with the inlet inverted arc 22 and the outlet inverted arc 23 through their own elastic deformation, without the need for additional fasteners, thereby reducing the assembly cost, and the upper clamping arc The engagement area between 62 and the inlet inverted arc 22 and the engagement area between the lower inverted arc 62 and the outlet inverted arc 23 can disperse the load, avoid stress concentration, and enhance the rigid structure between the silencer 6 and the air duct 2. A cavity is left between the silencer 6 and the air duct 2, and the cavity spacing between the two is 0 to 5.5 mm. A plurality of silencer holes 64 are evenly distributed on the inner straight section 61 and the lower inverted arc 63, wherein the silencer holes 64 are arranged on the inner straight section 61 and the lower inverted arc 63 corresponding to the cavity spacing of not less than 5 mm. The thickness of the silencer 6 is 1 to 1.5 mm, which can not only ensure that the silencer 6 has good elasticity, but also prevent excessive weight from affecting the later installation. When the gas vortex passes through the silencer hole 64 and enters the cavity between the silencer 6 and the air duct 2, it will produce reflection and interference due to the impedance mutation, thereby suppressing the noise of vortex shedding. At the same time, when the gas vortex hits the silencer 6, 1 to 1.The silencer 6 with a thickness of 5mm can play a buffering and sound-absorbing role. A wind hood 1 is installed above the air guide tube 2, and the wind hood 1 includes: a number of grille rings 11 with gradually increasing diameters and concentrically arranged. The grille ring 11 located on the innermost side serves as the center hole of the wind hood 1. Four brackets 4 are welded between each grille ring 11. The four brackets 4 are evenly distributed on the wind hood 1 around the circumference. The inner ends of the brackets 4 converge at the center hole of the wind hood 1. Two connecting rods 12 are equally welded on the grille ring 11 between each two adjacent brackets 4. The distance between each two adjacent grille rings 11 gradually increases from the inside to the outside. The outward expansion design of the distance between the grille rings 11 on the wind hood 1 can gradually release the airflow pressure to avoid sudden expansion and cause low-frequency aerodynamic noise. The motor 5 is located at The impeller 3 is fixed to the motor 5 within the innermost grille ring 11 and connected to the inner ends of the four brackets 4. The leading edge 311 of the blades 31 on the impeller 3 is lower than the trailing edge 312. Comb teeth 313 are provided on the trailing edge 312 of the blades 31. These teeth 313 on the trailing edge 312 of the blades 31 can decompose the single gas vortex generated by the rotation of the impeller 3 into multiple smaller vortices, reducing the intensity of vortex shedding and aerodynamic noise. The trailing edge 312 of the blades 31 does not fall below the top of the inner straight section 61, while the leading edge 311 of the blades 31 is higher than the bottom of the inner straight section 61. This ensures that the gas vortices generated by the impeller 3 are all noise-reduced by the muffler holes 64 and do not directly affect areas without muffler holes 64, which would cause the aerodynamic noise to radiate outward and reduce the noise reduction effect.
[0020] The ratio of the diameter d of the silencer hole 64 to the diameter D of the impeller 3 is: 0.004≤d / D≤0.01, which is similar to a frequency screen, accurately covering the noise spectrum peak generated when the impeller 3 rotates, controlling the resonance frequency and the sound absorption bandwidth. If the diameter d of the silencer hole 64 is too small, it will increase the airflow resistance and cause regenerative noise. If the diameter d of the silencer hole 64 is too large, the noise reduction effect will be reduced. Controlling d / D between 0.004 and 0.01 can balance the noise reduction effect and the airflow resistance. The ratio of the circumferential center distance L of the silencer hole 64 to the diameter D of the impeller 3 is: 0.03≤L / D≤0.08, which is similar to a phase interferer, breaking up the periodic noise generated when the impeller 3 rotates, and the circumferential density Too dense will interfere with the boundary layer flow and increase turbulent noise. Too sparse circumferential density will reduce the noise reduction coverage and the noise reduction effect. Controlling L / D between 0.03 and 0.08 can avoid secondary turbulence and ensure the noise reduction effect. The ratio between the axial center distance H of the silencer hole 64 and the diameter D of the impeller 3 is 0.0065≤H / D≤0.012, which is similar to an axial filter and matches the boundary layer development order. Excessive axial density will weaken the axial sound wave interference effect and reduce the noise reduction effect. Too small axial density will increase the friction loss between the airflow and the impeller, affecting the air output. Controlling H / D between 0.0065 and 0.012 can reduce noise without affecting the air output.
[0021] If the hood 1 is directly connected to the air duct 2, when the motor 5 drives the impeller 3 to rotate, it is easy to cause resonance between the hood 1 and the air duct 2 and generate vibration noise. In order to solve this problem, in this embodiment, the connection structure between the hood 1 and the air duct 2 is as follows: the outer ends of the four brackets 4 extend downward from the hood 1 and a connecting plate 41 is provided on the outer end of the bracket 4, a through hole is provided on the connecting plate 41, a T-shaped rubber sleeve 42 is clamped in the through hole, the small diameter end of the T-shaped rubber sleeve 42 extends into the through hole, the large diameter end of the T-shaped rubber sleeve 42 rests on the connecting plate 41, and the bottom of the connecting plate 41 is provided. An upper limit groove is provided on the lower wall, and a lower limit groove is provided on the bottom upper wall of the U-shaped seat 25. A composite buffer block 7 is mounted on the screw 251 of the U-shaped seat 25, and the composite buffer block 7 is snapped into the lower limit groove. The T-shaped rubber sleeve 42 on the connecting plate 41 is mounted on the screw 251 and abuts against the composite buffer block 7. The upper limit groove on the connecting plate 41 is snapped into the composite buffer block 7, and a locking nut 252 is threadedly connected to the screw 251. The locking nut 252 abuts against the large diameter end of the T-shaped rubber sleeve 42. Vibration is reduced by the composite buffer block 7, thereby reducing the generation of vibration noise.
[0022] The composite buffer block 7 includes: a buffer rubber block 71 and a buffer spring 72. An avoidance hole 711 for avoiding the screw 251 is provided at the center of the buffer rubber block 71. Four spring countersunk holes 712 are evenly distributed around the circumference of the buffer rubber block 71. A buffer spring 72 is inserted into each of the four spring countersunk holes 712. The buffer spring 72 rests on the bottom wall of the spring countersunk hole 712. The top of the buffer spring 72 is 1 to 1.5 mm lower than the top of the spring countersunk hole 712. When the connecting plate 41 on the bracket 4 is connected to the U-shaped seat 25, the locking nut 252 presses the buffer rubber block 71 into shape and then rests on the buffer spring 72 to limit the buffer spring 72. When the buffer rubber block 71 is compressed by 1 to After 1.5mm, elastic potential energy is stored. After the buffer rubber block 71 and the buffer spring 72 are matched, the natural frequency is staggered by the stiffness difference between the two, so as to prevent the composite buffer block 7 from resonating at a specific vibration frequency and amplifying the vibration noise. When a small vibration occurs between the wind hood 1 and the air guide tube 2, the buffer rubber block 71 can absorb the impact force generated by the small vibration through the stored elastic potential energy, thereby playing a buffering role, and the buffer spring 72 plays a supporting role. When a large vibration occurs, the buffer spring 72 can absorb the impact force generated by the large vibration and play a buffering role. The buffering effect of the buffer rubber block 71 and the buffer spring 72 can greatly reduce the vibration noise between the wind hood 1 and the air guide tube 2.
[0023] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the claims of the present invention.
Claims
1. Double-layer porous air-guiding and noise-reducing axial flow fan, including: The air hood, air guide tube, impeller, bracket and motor are characterized in that: a center hole is opened at the center position of the air hood, the bracket is fixed on the air hood circumference, the inner end of the bracket converges at the center hole, the motor is located in the center hole and is connected to the inner end of each bracket, the impeller is fixed on the motor, the leading edge of the blades on the impeller is lower than the trailing edge, and comb teeth are provided on the trailing edge. The outer end of the bracket extends downward from the air hood and a connecting plate with a through hole is provided on the outer end of the bracket. A plurality of notches are evenly distributed circumferentially on the upper edge of the air guide tube, and U-shaped seats are welded in the notches. A screw is vertically provided in the U-shaped seat, and a composite buffer block is mounted on the screw. The connecting plate is mounted on the screw through the through hole and rests on the composite buffer block. A locking nut is threaded on the screw, and the locking nut is screwed and rests on the connecting plate. A silencer is embedded in the air duct, and a cavity is left between the silencer and the air guide tube, and a plurality of silencer holes are evenly distributed circumferentially on the silencer.
2. The double-layer porous air-guiding and noise-reducing axial flow fan according to claim 1, characterized in that: The ratio between the diameter d of the silencer hole and the diameter D of the impeller is: 0.004≤d / D≤0.01, the ratio between the circumferential center distance L of the silencer hole and the diameter D of the impeller is: 0.03≤L / D≤0.08, and the ratio between the axial center distance H of the silencer hole and the diameter D of the impeller is 0.0065≤H / D≤0.
012.
3. The double-layer porous air-guiding and noise-reducing axial flow fan according to claim 1, characterized in that: The composite buffer block includes: a buffer rubber block and a buffer spring. An avoidance hole for avoiding the screw is provided at the center of the buffer rubber block. Four spring countersunk holes are evenly distributed around the circumference of the buffer rubber block. A buffer spring is inserted into each of the four spring countersunk holes. The bottom of the buffer spring rests on the bottom wall expanded by the spring, and the top of the buffer spring is 1 to 1.5 mm lower than the top of the spring countersunk hole.
4. The double-layer porous air-guiding and noise-reducing axial flow fan according to claim 3, characterized in that: A lower limit groove is provided on the bottom upper wall of the U-shaped seat, and an upper limit groove is provided on the bottom lower wall of the connecting plate. The upper side wall of the buffer rubber block is inserted into the upper limit groove, and the lower side wall of the buffer rubber block is inserted into the lower limit groove.
5. The double-layer porous air-guiding and noise-reducing axial flow fan according to claim 1, characterized in that: A T-shaped rubber sleeve is stuck in the through hole of the connecting plate, the small diameter end of the T-shaped rubber sleeve extends into the through hole, the large diameter end of the T-shaped rubber sleeve rests on the connecting plate, and the locking nut is screwed and rests on the large diameter end of the T-shaped rubber sleeve.
6. The double-layer porous air-guiding and noise-reducing axial flow fan according to claim 1, characterized in that: The connection structure between the silencer and the air guide tube is as follows: an outer straight section is provided in the middle of the air guide tube, and an outward-turned inlet arc and an outlet arc are integrally extended at the upper and lower ends of the outer straight section, and the upper edge is located on the inlet arc; an inner straight section is provided in the middle of the silencer, and an outward-turned upper clamping arc and a lower clamping arc are integrally extended at the upper and lower ends of the inner straight section, and the upper clamping arc and the lower clamping arc are respectively engaged with the inlet arc and the outlet arc through their own elastic deformation, and the silencer hole is provided on the inner straight section and the lower clamping arc.
7. The double-layer porous air-guiding and noise-reducing axial flow fan according to claim 6, characterized in that: The thickness of the silencer is 1-1.5 mm, and the cavity spacing between the silencer and the air guide tube is 0-5.5 mm. The silencer holes are arranged on the inner straight section and the lower inverted arc corresponding to the cavity spacing of not less than 5 mm.
8. The double-layer porous air-guiding and noise-reducing axial flow fan according to claim 7, characterized in that: The trailing edge of the blade is not lower than the top of the inner straight section, and the leading edge of the blade is higher than the bottom of the inner straight section.
9. The double-layer porous air-guiding and noise-reducing axial flow fan according to claim 1, characterized in that: The wind hood includes: a plurality of grille rings with gradually increasing diameters and arranged concentrically, the innermost grille ring serves as the center hole of the wind hood, the bracket is welded to each grille ring, and two connecting rods are equally welded on the grille ring between each two adjacent brackets.
10. The double-layer porous air-guiding and noise-reducing axial flow fan according to claim 9, characterized in that: The distance between each two adjacent grille rings gradually increases from the inside to the outside.