Low-noise centrifugal fan

Abstract

The invention relates to a low-noise centrifugal fan, and relates to the technical field of centrifugal fans, the low-noise centrifugal fan comprises a fan main body shell, and further comprises a buffer noise reduction structure arranged in the fan main body shell and used for buffering and silencing airflow; the impact absorption structure is arranged at the air inlet of the fan main body shell and is used for buffering air; the buffer noise reduction structure comprises an elastic buffer cushion layer fixedly connected to the interior of the draught fan body shell, the elastic buffer cushion layer is arranged to be matched with the buffer air chamber, the impact of airflow is absorbed through the elastic buffer cushion layer, and meanwhile, the buffer noise reduction structure is arranged in the buffer air chamber. A plurality of buffer air chambers arranged in the elastic buffer cushion layer are matched with valves for partition inside to counteract the impact force of air flow, and then noise generated by the impact force of air is secondarily adsorbed through first sound-absorbing cotton, so that the impact of the air flow on the shell of the fan main body is reduced; therefore, noise generated by vibration of the fan main body shell is reduced.

Description

Technical Field

[0001] The present application relates to a centrifugal fan, and in particular to a low-noise centrifugal fan. Background Art

[0002] A centrifugal fan is a mechanical device that uses the principle of centrifugal force to transport or pressurize gas. It is widely used in industry, construction, environmental protection and other fields. It is mainly composed of an air delivery impeller, a casing, an air inlet, an air outlet, and a transmission component. The air delivery impeller is the core component. It generates centrifugal force through high-speed rotation, throwing the gas to the outer edge of the air delivery impeller, and then discharged from the air outlet after being guided by the casing to achieve pressurization or transportation. The noise of the centrifugal fan mainly comes from mechanical vibration, air flow turbulence and component friction.

[0003] China Patent Network Publication No.: CN114046262A, provides an intelligent low-noise centrifugal fan, including a centrifugal fan body, a voltage-stabilized power supply, an air guide mechanism, and a vibration frequency and vibration force detection mechanism; the inner ends of multiple air delivery impellers are respectively rotatably mounted on the outer side of a flange at the front end of a power motor shaft, and the shaft is a hollow mechanism; the air guide mechanism includes a bearing and a sleeve, the bearing is mounted in the front end of the sleeve, and a connecting pipe is mounted at the rear end of the sleeve. The outer end of the sleeve is mounted together with the shell of the centrifuge body, and the connecting pipe is connected to the wind shell of the centrifugal fan body through a pipeline; the vibration frequency and vibration force detection mechanism includes a probe and a data transmission circuit, the lower end of the probe has mercury, and multiple metal sheets are mounted on the side of the probe; the probe is mounted in the base of the centrifugal fan body, and the data transmission circuit and the voltage-stabilized power supply are mounted in the electric control box and electrically connected to the probe. The present invention improves the heat dissipation efficiency of the power motor, reduces the vibration of the whole machine and the probability of generating large noise, and the user can monitor the vibration force and vibration frequency of the fan body in real time.

[0004] This solution uses multiple heads to inspect the inside of the fan, which is expensive. At the same time, the noise reduction of the fan is only handled by installation and rotor heat dissipation, completely ignoring the noise generated by the air flow itself. Therefore, a low-noise centrifugal fan is proposed. Summary of the Invention

[0005] The purpose of this application is to provide a low-noise centrifugal fan, which is used to buffer the air flow at the air inlet of the centrifugal fan and buffer the air flow impact inside the shell, thereby reducing noise.

[0006] In a first aspect, the present application provides a low-noise centrifugal fan adopting the following technical solution: comprising a fan main body housing, and further comprising: A buffering and noise reduction structure is provided inside the fan main body housing to buffer and silence the airflow; A shock absorbing structure, which is installed at the air inlet of the fan body housing to cushion the air; The buffering noise reduction structure includes an elastic buffering pad fixedly connected to the inside of the fan main body shell, and a plurality of buffer air chambers are equidistantly arranged inside the elastic buffering pad. Through the elastic buffering pad and the buffering air chambers, the elastic buffering pad itself absorbs part of the impact of the airflow, and at the same time, the air inside the buffering air chamber can absorb part of the impact, thereby preventing the airflow from directly hitting the shell, thereby reducing the vibration of the shell and further reducing the noise generated by the vibration. A first sound-absorbing cotton is fixedly connected to one side of the elastic buffering pad; The impact absorbing structure includes an elastic buffer layer fixedly connected to the fan main body shell at one end and a guide support frame fixedly connected to the fan main body shell. A support slope is provided on the side of the guide support frame close to the elastic buffer layer.

[0007] Preferably, a power motor is installed on one side of the fan main body casing, and an air delivery impeller is fixedly connected to the output end of the power motor. The air delivery impeller is rotatably connected to the inside of the fan main body casing, and a second sound-absorbing cotton is provided at the air outlet of the fan main body casing. The second sound-absorbing cotton provided at the air outlet can absorb the flow noise when the airflow is discharged from the air outlet, thereby further reducing the overall noise of the fan.

[0008] Preferably, the output end of the power motor is fixedly connected to the air delivery impeller, and the air delivery impeller is driven to rotate by the power motor. The power motor is installed on the side of the fan main body casing away from the air inlet and the power motor is fixedly connected to the fan main body casing.

[0009] Preferably, a plurality of groups of backward-curved blades are provided inside the air delivery impeller. The design of the backward-curved blades can reduce the flow separation of the gas in the impeller through the air flow outlet angle and reduce the vortex loss. Its efficiency is usually higher than that of radial blades. The end of the blade facing the air inlet is set to be smooth, and the outer edge of the blade is serrated. At the same time, the inner edge and the outer edge of the blade are set to be smooth and serrated respectively, which can reduce the generation of vortex and reduce turbulent noise, thereby reducing the noise of the air flow when the air flow passes through the impeller.

[0010] Preferably, the elastic buffer layer corresponds to the shape of the inner wall of the fan main body casing, the first sound-absorbing cotton is fixedly connected to the fan main body casing, and the first sound-absorbing cotton is located between the fan main body casing and the elastic buffer layer. An air collecting channel is provided on one side of the elastic buffer layer, and the air collecting channel is opened inside the fan main body casing.

[0011] Preferably, a telescopic airbag is provided on the top of the air collecting channel, and the telescopic airbag is distributed in a ring shape inside the main casing of the fan. The telescopic airbag is arranged to be distributed in a ring shape so that it can diffuse stably outward, thereby pushing the sliding traction block to move synchronously outward. The telescopic airbag is connected to the air collecting channel.

[0012] Preferably, when the elastic buffer layer is squeezed by the air flow delivered by the air delivery impeller, the air in the buffer air chamber in the middle of the elastic buffer layer is squeezed, discharged from the inside of the buffer air chamber to the air collecting channel, and concentratedly input from the air collecting channel into the inside of the telescopic airbag, causing the telescopic airbag to expand.

[0013] Preferably, the elastic buffer cortex is arranged at the air inlet of the fan main body casing, and the end of the elastic buffer cortex close to the air inlet is fixedly connected to the fan main body casing. The elastic buffer cortex is arranged at the air inlet of the fan main body casing, so that the air sucked by the air delivery impeller will first pass through the elastic buffer cortex, and the elastic buffer cortex will first partially absorb the impact of the air, thereby reducing the vibration caused by the impact of the air on the casing. The guide support frame is distributed in a ring shape inside the elastic buffer cortex, and the support inclined surface conflicts with the elastic buffer cortex. A sliding traction block is slidably connected inside the support inclined surface.

[0014] Preferably, the telescopic airbag is fixedly connected to the sliding traction block, and the telescopic airbags are separated from each other by partitions. At the same time, the air collecting channels in the corresponding areas of the telescopic airbags are synchronously separated by partitions. The telescopic airbag and the air collecting channels in the corresponding areas of the telescopic airbag are separated by the partitions, so that the telescopic airbags can be transported with the same amount of air, thereby achieving the same degree of synchronous expansion of the telescopic airbags. The telescopic airbag is located on the lower side of the guide support frame, and the top of the sliding traction block is fixedly connected to one end of the elastic buffer cortex.

[0015] Preferably, when the sliding traction block is pushed by the expansion of the telescopic airbag, the sliding traction block slides outward along the guide support frame, and at the same time, the sliding traction block synchronously pulls the elastic buffer cortex to move, so that the elastic buffer cortex is pulled outward by the sliding traction block and opens, so that the elastic buffer cortex expands outward into a trumpet shape.

[0016] In summary, this application includes at least one of the following beneficial technical effects: 1. By arranging an elastic buffer layer and a buffer air chamber, the elastic buffer layer absorbs the impact of the airflow to reduce the impact of the gas on the elastic buffer layer. At the same time, the multiple buffer air chambers set inside the elastic buffer layer cooperate with the internal partition valve to offset the impact force of the airflow. Then, the first sound-absorbing cotton absorbs the noise generated by the impact force of the gas for a second time, thereby reducing the impact of the airflow on the fan main body casing and reducing the noise generated by the vibration of the fan main body casing. 2. An impact absorbing structure is provided to absorb the impact of the airflow out of the fan inlet and reduce the noise of the fan. The telescopic airbag expands outward, and the telescopic airbag pushes the sliding traction block to slide outward, so that the sliding traction block drives the elastic buffer cortex to slide along the guide support frame, so that the elastic buffer cortex is pulled and expanded, and the elastic buffer cortex is gradually pulled tight. At the same time, the elastic buffer cortex tilts toward the guide support frame and changes from a channel shape to a trumpet shape, absorbing the impact of the air flow while avoiding blocking the air intake of the air inlet, thereby achieving the effect of reducing noise. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the overall structure of Example 1 of the present application; Figure 2 is a schematic cross-sectional view of the main body of Example 1 of the present application; Figure 3 This is a schematic cross-sectional view of the front body of Example 1 of the present application; Figure 4 is a schematic cross-sectional view of the gas collecting channel of Example 1 of the present application; Figure 5 Schematic diagram of the connection between the buffer noise reduction structure and the impact absorption structure of Example 1 of the present application; Figure 6 It is an enlarged cross-sectional view of the impact absorbing structure of Example 1 of the present application.

[0018] Explanation of the accompanying symbols: 1. Fan main body casing; 2. Power motor; 3. Air delivery impeller; 4. Second sound-absorbing cotton; 5. Buffering and noise reduction structure; 501. Elastic buffer pad layer; 502. Buffer air chamber; 503. First sound-absorbing cotton; 504. Air collecting channel; 505. Telescopic airbag; 6. Impact absorbing structure; 601. Elastic buffer cortex; 602. Guide support frame; 603. Support slope; 604. Sliding traction block. DETAILED DESCRIPTION

[0019] The following is combined with Figure 1 -Attached Figure 6 , further details of this application are given.

[0020] Example 1: A low noise centrifugal fan, referring to Figures 1 to 6 , including a fan main body casing 1, and also including: A buffering and noise reduction structure 5 is provided inside the fan main body housing 1 for buffering and silencing the airflow; A shock absorbing structure 6 is installed at the air inlet of the fan main body housing 1 to buffer the air; The buffering and noise reduction structure 5 includes an elastic buffering layer 501 fixedly connected to the inside of the fan main body housing 1, a plurality of buffering air chambers 502 are evenly arranged inside the elastic buffering layer 501, and a first sound-absorbing cotton 503 is fixedly connected to one side of the elastic buffering layer 501; The impact absorbing structure 6 includes an elastic buffer layer 601 fixedly connected to the fan main housing 1 at one end and a guide support frame 602 fixedly connected to the fan main housing 1 . A support slope 603 is provided on one side of the guide support frame 602 close to the elastic buffer layer 601 .

[0021] By adopting the above technical solution, the power motor 2 drives the air delivery impeller 3 to rotate. At this time, the air delivery impeller 3 draws air from the air inlet of the fan main body housing 1 to the interior of the fan main body housing 1. The air enters the interior of the air delivery impeller 3. When the air passes through the blades of the air delivery impeller 3, since the end of the blade of the air delivery impeller 3 facing the air inlet is set to be smooth, and the outer edge of the blade is serrated, when the air contacts the blades of the air delivery impeller 3, the smooth blades and the serrated outer edge will reduce the vortex generated by separation and turbulence when the air passes through the blades, thereby reducing the noise of the air inlet. At the same time, the elastic buffer cortex 601 of the air inlet can buffer the air flow formed at the air inlet to further reduce the noise. When the air flow enters the inside of the fan main body casing 1 from the air delivery impeller 3, the air flow will rush towards the elastic buffer layer 501 on the inner wall of the fan main body casing 1. When the gas impacts the elastic buffer layer 501, the multiple buffer air chambers 502 arranged inside the elastic buffer layer 501 cooperate with the internal partition valve to offset the impact force of the air flow. Then, the first sound-absorbing cotton 503 absorbs the noise generated by the impact force of the gas for a second time, thereby reducing the impact of the air flow on the fan main body casing 1 and reducing the noise generated by the vibration of the fan main body casing 1. At the same time, the air inside the elastic buffer layer 501 is squeezed into the air collecting channel. The elastic buffer cortex 601 is pulled and expanded, and the elastic buffer cortex 601 is gradually pulled tight. At the same time, the elastic buffer cortex 601 tilts toward the guide support frame 602, and changes from a channel shape to a trumpet shape. This absorbs the impact of the air flow while avoiding blocking the air intake at the air inlet, thereby achieving the effect of reducing noise.

[0022] Specifically, a power motor 2 is installed on one side of the fan main body casing 1, and an air delivery impeller 3 is fixedly connected to the output end of the power motor 2. The air delivery impeller 3 is rotatably connected to the inside of the fan main body casing 1, and a second sound-absorbing cotton 4 is provided at the air outlet of the fan main body casing 1.

[0023] By adopting the above technical solution, a power motor 2 and an air delivery impeller 3 are provided, and the power motor 2 drives the air delivery impeller 3 to rotate, so that the air delivery impeller 3 draws external air into the inside of the fan main body casing 1 and increases the kinetic energy of the gas. The second sound-absorbing cotton 4 is provided to absorb the noise of the air flow at the air outlet of the fan main body casing 1 to reduce the noise at the air outlet of the fan.

[0024] Specifically, the output end of the power motor 2 is fixedly connected to the air delivery impeller 3, and the air delivery impeller 3 is driven by the power motor 2 to rotate. The power motor 2 is installed on the side of the fan main body casing 1 away from the air inlet and the power motor 2 is fixedly connected to the fan main body casing 1. A plurality of groups of backward curved blades are arranged inside the air delivery impeller 3. The end of the blade facing the air inlet is set to be smooth, and the outer edge of the blade is serrated.

[0025] By adopting the above technical solution, the power motor 2 is used to drive the air delivery impeller 3 to rotate, and the blades of the air delivery impeller 3 close to the air inlet side are set to be smooth, so that when the airflow passes through the smooth blades, the airflow is prevented from suddenly turning at the leading edge of the blade, reducing the risk of flow separation, improving the air intake efficiency, and reducing vortex generation and turbulent noise. The outer edge of the blade is set to be serrated, which can break the large-scale vortex formed by the airflow into small vortices through the serrated structure, reduce vortex noise, and make the noise more easily absorbed by the muffler or attenuated by the air, thereby achieving the effect of reducing noise.

[0026] Specifically, the elastic buffer layer 501 corresponds to the shape of the inner wall of the fan main body casing 1, the first sound-absorbing cotton 503 is fixedly connected to the fan main body casing 1, and the first sound-absorbing cotton 503 is located between the fan main body casing 1 and the elastic buffer layer 501. An air collecting channel 504 is provided on one side of the elastic buffer layer 501. The air collecting channel 504 is opened inside the fan main body casing 1, and a telescopic airbag 505 is provided on the top of the air collecting channel 504. The telescopic airbag 505 is distributed in a ring shape inside the fan main body casing 1, and the telescopic airbag 505 is connected to the air collecting channel 504.

[0027] By adopting the above technical solution, the setting of the buffering and noise reduction structure 5 can absorb the impact of the airflow through the elastic buffering pad layer 501 and the buffering air chamber 502, and prevent the airflow from hitting the shell, thereby reducing noise. At the same time, the first sound-absorbing cotton 503 on the outside of the elastic buffering pad layer 501 can further absorb impact and noise. At the same time, the elastic buffering pad layer 501 is set to correspond to the internal shape of the fan main body shell 1, so as to achieve overall protection of the fan main body shell 1. At the same time, when the air inside the buffering air chamber 502 is impacted by the airflow, it will be squeezed out of the buffering air chamber 502 and transported into the interior of the telescopic airbag 505 through the air collecting channel 504.

[0028] Specifically, when the elastic buffer layer 501 is squeezed by the air flow delivered by the air delivery impeller 3, the air in the buffer air chamber 502 in the middle of the elastic buffer layer 501 is squeezed, discharged from the inside of the buffer air chamber 502 to the air collecting channel 504, and concentratedly input from the air collecting channel 504 to the inside of the telescopic airbag 505, causing the telescopic airbag 505 to expand.

[0029] By adopting the above technical solution, when the elastic buffer layer 501 is squeezed by the air flow delivered by the air delivery impeller 3, the air in the buffer air chamber 502 in the middle of the elastic buffer layer 501 is squeezed, discharged from the inside of the buffer air chamber 502 to the air collecting channel 504, and concentratedly input from the air collecting channel 504 to the inside of the telescopic airbag 505, causing the telescopic airbag 505 to expand, thereby pushing the sliding traction block 604 to move.

[0030] Specifically, the elastic buffer cortex 601 is arranged at the air inlet of the fan main casing 1, and the end of the elastic buffer cortex 601 close to the air inlet is fixedly connected to the fan main casing 1, the guide support frame 602 is distributed in a ring shape inside the elastic buffer cortex 601, the support slope 603 is in conflict with the elastic buffer cortex 601, and the support slope 603 is slidably connected to the inside of the sliding traction block 604.

[0031] By adopting the above technical solution, the elastic buffer cortex 601 is set at the air inlet of the fan main body shell 1, so that the elastic buffer cortex 601 can absorb the impact of the air sucked by the air delivery impeller 3, so that the air inside the fan main body shell 1 that has not entered will impact the elastic buffer cortex 601 instead of the shell at the air inlet. At the same time, the elastic buffer cortex 601 will open to form a trumpet-shaped air duct after being pulled by the sliding traction block 604, which increases the air intake range while dispersing the pressure of the intake air. The opened air duct makes the speed of air entering more stable, avoiding the excessive air flow speed caused by the air inlet duct remaining unchanged when the speed of the air delivery impeller 3 increases, reducing the probability of air turbulence, and further reducing the noise of the air inlet.

[0032] Specifically, the telescopic airbag 505 is fixedly connected to the sliding traction block 604, and the telescopic airbags 505 are separated from each other by partitions. At the same time, the air collecting channels 504 in the corresponding areas of the telescopic airbags 505 are synchronously separated by partitions. The telescopic airbag 505 is located on the lower side of the guide support frame 602, and the top of the sliding traction block 604 is fixedly connected to one end of the elastic buffer cortex 601.

[0033] By adopting the above technical solution, by fixedly connecting the telescopic airbag 505 with the sliding traction block 604, when the elastic buffer pad layer 501 is not squeezed, the air inside the telescopic airbag 505 will be sucked back into the buffer air chamber 502 by the reset elastic buffer pad layer 501, so that the telescopic airbag 505 contracts and drives the sliding traction block 604 to reset, so as to release the stretching of the elastic buffer cortex 601. When the elastic buffer pad layer 501 is squeezed by the airflow, the airflow velocity delivered by the air delivery impeller 3 can be used to make the elastic buffer pad layer 501 squeezed to different degrees, thereby causing the buffer air chamber 502 to discharge different amounts of air, so that the telescopic airbag 505 expands, and the sliding traction block 604 moves to stretch and open the elastic buffer cortex 601.

[0034] Specifically, when the sliding traction block 604 is pushed by the expansion of the telescopic airbag 505, the sliding traction block 604 slides outward along the guide support frame 602, and at the same time, the sliding traction block 604 synchronously pulls the elastic buffer cortex 601 to move, so that the elastic buffer cortex 601 is pulled outward by the sliding traction block 604 and opens, so that the elastic buffer cortex 601 expands outward into a trumpet shape.

[0035] By adopting the above technical solution, when the sliding traction block 604 is pushed by the expansion of the telescopic airbag 505, the sliding traction block 604 slides outward along the guide support frame 602, and at the same time, the sliding traction block 604 synchronously pulls the elastic buffer cortex 601 to move, so that the elastic buffer cortex 601 is pulled outward by the sliding traction block 604 and opens, so that the elastic buffer cortex 601 expands outward into a trumpet shape.

[0036] The implementation principle of the embodiment of the present application is as follows: during operation, the air delivery impeller 3 is driven to rotate by the power motor 2. At this time, the air delivery impeller 3 draws air from the air inlet of the fan main body housing 1 to the interior of the fan main body housing 1. The air enters the interior of the air delivery impeller 3. When the air passes through the blades of the air delivery impeller 3, since the end of the blades of the air delivery impeller 3 facing the air inlet is set to be smooth, and the outer edge of the blade is serrated, when the air contacts the blades of the air delivery impeller 3, the smooth blades and the serrated outer edge will reduce the vortex generated by separation and turbulence when the air passes through the blades, thereby reducing the noise of the air inlet. At the same time, the elastic buffer cortex 601 of the air inlet can buffer the air flow formed at the air inlet to further reduce the noise. When the air flow enters the inside of the fan main body casing 1 from the air delivery impeller 3, the air flow will rush towards the elastic buffer layer 501 on the inner wall of the fan main body casing 1. When the gas impacts the elastic buffer layer 501, the multiple buffer air chambers 502 arranged inside the elastic buffer layer 501 cooperate with the internal partition valve to offset the impact force of the air flow. Then, the first sound-absorbing cotton 503 absorbs the noise generated by the impact force of the gas for a second time, thereby reducing the impact of the air flow on the fan main body casing 1 and reducing the noise generated by the vibration of the fan main body casing 1. At the same time, the air inside the elastic buffer layer 501 is squeezed into the air collecting channel. The elastic buffer cortex 601 is pulled and expanded, and the elastic buffer cortex 601 is gradually pulled tight. At the same time, the elastic buffer cortex 601 tilts toward the guide support frame 602, and changes from a channel shape to a trumpet shape. This absorbs the impact of the air flow while avoiding blocking the air intake at the air inlet, thereby achieving the effect of reducing noise.

[0037] The examples of this specific embodiment are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Identical components are represented by the same reference numerals. Therefore, any equivalent changes made based on the structure, shape, and principle of this application should be included in the scope of protection of this application.

Claims

1. A low-noise centrifugal fan, comprising a fan main body housing (1), characterized in that: Also includes: A buffering and noise reduction structure (5) is arranged inside the fan main body housing (1) and is used to buffer and silence the airflow; An impact absorbing structure (6) is mounted on the air inlet of the fan main body housing (1) to buffer the air; The buffering noise reduction structure (5) comprises an elastic buffering pad (501) fixedly connected to the inside of the fan main body housing (1), a plurality of buffering air chambers (502) are equidistantly arranged inside the elastic buffering pad (501), and a first sound-absorbing cotton (503) is fixedly connected to one side of the elastic buffering pad (501); The impact absorbing structure (6) comprises an elastic buffering layer (601) fixedly connected to the fan main body housing (1) at one end, and a guide support frame (602) fixedly connected to the fan main body housing (1), wherein a support inclined surface (603) is provided on a side of the guide support frame (602) close to the elastic buffering layer (601).

2. The low-noise centrifugal fan according to claim 1, characterized in that: A power motor (2) is installed on one side of the fan main body housing (1), and an air delivery impeller (3) is fixedly connected to the output end of the power motor (2). The air delivery impeller (3) is rotatably connected to the inside of the fan main body housing (1), and a second sound-absorbing cotton (4) is provided at the air outlet of the fan main body housing (1).

3. The low-noise centrifugal fan according to claim 2, characterized in that: The output end of the power motor (2) is fixedly connected to the air delivery impeller (3), and the power motor (2) drives the air delivery impeller (3) to rotate. The power motor (2) is installed on a side of the fan main body housing (1) away from the air inlet, and the power motor (2) is fixedly connected to the fan main body housing (1).

4. The low-noise centrifugal fan according to claim 2, characterized in that: The air delivery impeller (3) is internally provided with a plurality of groups of backward curved blades, the ends of the blades facing the air inlet are arranged in a smooth shape, and the outer edges of the blades are serrated.

5. The low-noise centrifugal fan according to claim 1, characterized in that: The elastic buffer layer (501) corresponds to the shape of the inner wall of the fan main body shell (1); the first sound-absorbing cotton (503) is fixedly connected to the fan main body shell (1); and the first sound-absorbing cotton (503) is located between the fan main body shell (1) and the elastic buffer layer (501); an air collecting channel (504) is provided on one side of the elastic buffer layer (501); and the air collecting channel (504) is opened inside the fan main body shell (1).

6. The low-noise centrifugal fan according to claim 5, characterized in that: A telescopic airbag (505) is provided at the top of the air collecting channel (504), the telescopic airbag (505) is distributed in a ring shape inside the fan main body housing (1), and the telescopic airbag (505) is connected to the air collecting channel (504).

7. The low-noise centrifugal fan according to claim 6, characterized in that: When the elastic cushion layer (501) is squeezed by the air flow delivered by the air delivery impeller (3), the air in the buffer air chamber (502) in the middle of the elastic cushion layer (501) is squeezed and discharged from the inside of the buffer air chamber (502) to the air collecting channel (504), and then concentratedly input from the air collecting channel (504) into the inside of the telescopic airbag (505), causing the telescopic airbag (505) to expand.

8. The low-noise centrifugal fan according to claim 1, characterized in that: The elastic buffer cortex (601) is arranged at the air inlet of the fan main body housing (1), and one end of the elastic buffer cortex (601) close to the air inlet is fixedly connected to the fan main body housing (1), the guide support frame (602) is distributed in an annular shape inside the elastic buffer cortex (601), the support inclined surface (603) is in conflict with the elastic buffer cortex (601), and a sliding traction block (604) is slidably connected inside the support inclined surface (603).

9. The low-noise centrifugal fan according to claim 6, characterized in that: The telescopic airbag (505) is fixedly connected to the sliding traction block (604), and the telescopic airbags (505) are separated from each other by partitions. At the same time, the air collecting channels (504) in the corresponding areas of the telescopic airbags (505) are synchronously separated by partitions. The telescopic airbag (505) is located on the lower side of the guide support frame (602), and the top of the sliding traction block (604) is fixedly connected to one end of the elastic buffer cortex (601).

10. The low-noise centrifugal fan according to claim 8, characterized in that: When the sliding traction block (604) is pushed by the expansion of the telescopic airbag (505), the sliding traction block (604) slides outward along the guide support frame (602), and at the same time, the sliding traction block (604) synchronously pulls the elastic buffer cortex (601) to move, so that the elastic buffer cortex (601) is pulled outward by the sliding traction block (604) and opens, so that the elastic buffer cortex (601) expands outward into a trumpet shape.

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