Noise reduction aerodynamic device for a breathing machine

Abstract

The present application relates to a kind of breathing machine's noise reduction aerodynamic device, including shell, the shell includes inner cavity and air inlet, the shell is equipped with for fixing fan fan bracket, the fan bracket will the inner cavity be divided into first chamber being communicated with the air inlet and second chamber being communicated with fan inlet, the first chamber and second chamber are communicated by the multiple airflow passages being arranged circumferentially around fan.The aerodynamic noise reduction device of the present application, the chaotic airflow entering from air inlet is buffered in the first chamber Speed reduction, and after the shunt carding of the multiple airflow passages being arranged circumferentially around fan, can reduce impedance and eddy current, so that airflow becomes smooth and smooth.After airflow enters second chamber, speed reduction is carried out again.Finally, the airflow flow rate entering fan inlet is reduced, and vortex is not prone to produce, and the aerodynamic noise at fan inlet is smaller.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of respirators, and particularly relates to a noise reduction aerodynamic device of a respirator. BACKGROUND

[0002] With the continuous progress of science and technology and the continuous improvement of living standards, respirators have gradually entered the public view and entered many families. A respirator is composed of a fan, a control circuit, a sensor, an airflow output pipe and a mask. According to the pre-set, the machine continuously outputs a certain level of positive pressure and flow of airflow, which is applied to the upper respiratory tract of the patient through the pipeline and the nasal mask, and the positive pressure airflow keeps the patient's upper airway open and usually eliminates snoring, low ventilation and sleep apnea.

[0003] When the respirator works, the air source needs to be provided by the outside. However, the turbine fan, as a key component of the respirator, has a high noise value in the working process, which causes great trouble to the patient, especially affects the sleep condition of the patient. On the one hand, when the motor in the fan drives the fan blades to rotate at high speed, the motor and the fan blades will produce vibration noise; on the other hand, the fan blades rotate at high speed to stir the airflow, and the friction between the blades and the air will produce aerodynamic noise, especially at the inlet of the fan, the airflow is turbulent and even vortex, and the noise is very large. In the prior art, in order to reduce the noise, the fan is coated with a sound-absorbing material outside, which can reduce part of the noise, but the coating material makes the fan not easy to dissipate heat, and the temperature of the fan is often in a high state, which affects the service life of the fan.

[0004] Therefore, it is necessary to provide a noise reduction aerodynamic device for a respirator to solve the technical problems existing in the prior art. SUMMARY

[0005] The present application provides a noise reduction aerodynamic device for a respirator to solve at least one of the above technical problems.

[0006] The technical scheme adopted by the present application is as follows:

[0007] The present application provides a noise reduction aerodynamic device for a respirator, which comprises a shell, the shell comprises an inner cavity and an air inlet, a fan support for fixing a fan is arranged in the shell, the fan support divides the inner cavity into a first chamber communicating with the air inlet and a second chamber communicating with the fan inlet, and the first chamber and the second chamber are communicated through a plurality of airflow channels arranged circumferentially around the fan.

[0008] As a preferred embodiment of the present application, the shell comprises a lower shell for supporting the fan support, the air inlet is arranged on the bottom wall of the lower shell, and the lower shell is provided with the airflow channels; or,

[0009] The lower shell and the fan support frame jointly form the airflow channel.

[0010] As a preferred embodiment of the present application, the airflow channel is arranged in the axial direction of the fan turbine from the air inlet end to the air outlet end.

[0011] As a preferred embodiment of the present application, the airflow channel is arranged in an inclined direction from the air inlet end to the air outlet end, the inclined direction being the same as the turbine rotation direction of the fan; or,

[0012] The inclined direction is from inside to outside in the radial direction of the fan inlet.

[0013] As a preferred embodiment of the present application, the first chamber is provided with a first flow guide part, the first flow guide part comprising a plurality of first flow guide ribs extending from the air inlet to the airflow channel, the first flow guide ribs dividing the first chamber to form a plurality of first flow-through areas, the first flow-through areas being arranged one-to-one corresponding to the airflow channel.

[0014] As a preferred embodiment of the present application, the width of the first flow-through area gradually increases in the direction from the air inlet to the air inlet end of the airflow channel.

[0015] As a preferred embodiment of the present application, the shell comprises a lower shell for supporting the fan support frame, the air inlet is arranged on the bottom wall of the lower shell, and the first flow guide part further comprises a flow guide ring rib arranged circumferentially around the air inlet.

[0016] As a preferred embodiment of the present application, the second chamber is provided with a second flow guide part, the second flow guide part comprising a plurality of second flow guide ribs arranged around the fan inlet area, the second flow guide ribs extending from the airflow channel to the fan inlet, the second flow guide ribs dividing the fan inlet area to form a plurality of second flow-through areas, the second flow-through areas being arranged one-to-one corresponding to the airflow channel.

[0017] As a preferred embodiment of the present application, the second flow guide part further comprises third flow guide ribs extending from the airflow channel to the fan inlet, the third flow guide ribs being arranged in a staggered manner with the second flow guide ribs in the circumferential direction of the fan inlet, and the third flow guide ribs being arranged one-to-one corresponding to the airflow channel.

[0018] As a preferred embodiment of the present application, in the radial direction of the fan inlet, the third flow guide ribs are arranged on the outer side of the second flow guide ribs.

[0019] As a preferred embodiment of the present application, the second flow guide ribs and the third flow guide ribs are both provided with flow guide arc surfaces, the flow guide arc surfaces being curved in the direction opposite to the turbine rotation direction of the fan.

[0020] As a preferred embodiment of the present application, the width of the second flow passage gradually decreases in the direction from the air outlet end of the air flow passage to the fan inlet.

[0021] As a preferred embodiment of the present application, the first flow guide part further comprises a first flow guide cone arranged towards the air inlet, and the peripheral surface of the first flow guide cone is an inner concave curved surface; and / or,

[0022] The second flow guide part further comprises a second flow guide cone arranged towards the fan inlet, and the peripheral surface of the second flow guide cone is an inner concave curved surface.

[0023] As a preferred embodiment of the present application, the shell further comprises a sound attenuation cavity arranged along the air flow direction of the fan outlet;

[0024] The sound attenuation cavity is provided with a partition plate, and the partition plate can at least divide the sound attenuation cavity into a first sound attenuation cavity connected to the fan outlet and a second sound attenuation cavity arranged around the first sound attenuation cavity.

[0025] As a preferred embodiment of the present application, the partition plate is provided with a through hole connecting the second sound attenuation cavity and the first sound attenuation cavity; and / or,

[0026] The second sound attenuation cavity is filled with sound-absorbing material.

[0027] Due to the adoption of the above technical solutions, the present application has the following beneficial effects:

[0028] 1. The noise reduction aerodynamic device of the breathing machine provided by the present application, the flow direction of the air flow from the air inlet to the fan inlet is that the air flow first enters the first chamber through the air inlet, then enters the second chamber through the plurality of air flow passages arranged around the fan from the first chamber, and finally enters the fan inlet. The chaotic air flow entering from the air inlet is buffered and slowed down in the first chamber, and is divided when entering the plurality of air flow passages arranged around the fan, and the air flow is combed through the air flow passages to reduce impedance and vortex, so that the air flow becomes smooth. After the air flow enters the second chamber, it is slowed down again, and finally, the air flow entering the fan inlet has a low flow rate and is not easy to produce vortex, and the aerodynamic noise at the fan inlet is small. Moreover, when the vibration noise generated by the motor and the fan blades rotating is transmitted to the surrounding, the plurality of air flow passages arranged around the fan, as well as the first chamber and the second chamber, can simultaneously act as a noise reduction cavity to block the transmission of vibration noise. Thus, the aerodynamic noise reduction device of the present application can realize the noise reduction of the breathing machine and improve the user's experience.

[0029] 2. As a preferred embodiment of the present application, the shell comprises a lower shell for supporting the fan support, the air inlet is arranged on the bottom wall of the lower shell, and the first chamber is also arranged on the lower part, and the airflow moves from bottom to top along the airflow passage to the second chamber, which is conducive to reducing the flow rate of the gas. In one way, the airflow passage and the lower shell are integrally formed, which is more convenient for processing and assembly. In another way, the lower shell and the fan support jointly form the airflow passage, and the fan support extends the length of the airflow passage, which is conducive to improving the rectification effect.

[0030] 3. As a preferred embodiment of the present application, a first flow guide part is arranged in the first chamber, and the first chamber is divided into a plurality of first flow-through zones by the first flow guide part. The airflow entering from the air inlet is divided into different first flow-through zones in the first chamber, and is guided and combed by the first flow guide ribs, so that the airflow can enter the airflow passage more smoothly, which is conducive to improving the rectification effect and reducing the aerodynamic noise of the airflow and the chamber wall. Further, the width of the first flow-through zone gradually increases, the flow-through section of the airflow changes, and the impedance also changes accordingly, which can weaken noise of different frequencies.

[0031] 4. As a preferred embodiment of the present application, a second flow guide part is arranged in the second chamber, and the fan inlet area is divided into a plurality of second flow-through zones. The airflow passing out of the airflow passage is guided and combed again by the second flow guide ribs, so that the airflow entering the fan inlet is more smooth and does not produce vortex, thereby reducing the aerodynamic noise of the fan inlet. Further, the second flow guide part further comprises third flow guide ribs extending along the airflow passage to the fan inlet, and the third flow guide ribs are arranged one by one corresponding to the airflow passage. The airflow passing out of the airflow passage outlet flows to the fan inlet under the guidance of the third flow guide ribs. Further, the second flow guide ribs and the third flow guide ribs have flow guide arc surfaces, the guide direction of the flow guide arc surfaces is the same as the rotation direction of the turbine, so that the airflow enters the fan inlet along the direction of the turbine rotation direction, avoiding turbulence and reducing the noise generated by the friction between the turbine blades and the air.

[0032] 5. As a preferred embodiment of the present application, the shell is provided with a sound attenuation chamber at the fan outlet to eliminate the noise generated by the high-speed airflow at the fan outlet. The noise is constantly reflected, refracted, etc. with the chamber wall of the sound attenuation chamber, and the energy is reduced, which is conducive to reducing the noise of the fan outlet. Moreover, the longer the extension distance of the sound attenuation chamber is, the more obvious the noise reduction effect is. The sound attenuation chamber comprises at least two layers of sound attenuation chambers arranged in a surrounding manner to block the transmission of noise outward. Further, the partition plate is provided with a through hole communicating the first sound attenuation chamber and the second sound attenuation chamber, the noise passes through the through hole, the acoustic resistance increases, and the noise is absorbed in a targeted manner. After the noise enters the second sound attenuation chamber, it is constantly emitted and refracted, and the noise energy gradually decreases. The second sound attenuation chamber is filled with sound-absorbing material, which further plays a role in sound absorption and noise reduction. BRIEF DESCRIPTION OF DRAWINGS

[0033] The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the application. In the drawings:

[0034] Figure 1 A structural schematic view of a noise reduction aerodynamic device provided for an embodiment of the present application;

[0035] Figure 2 An exploded view of a noise reduction aerodynamic device provided for an embodiment of the present application;

[0036] Figure 3 A semi-sectional view of a noise reduction aerodynamic device provided for an embodiment of the present application;

[0037] Figure 4 A sectional view of a noise reduction aerodynamic device provided for an embodiment of the present application;

[0038] Figure 5 A structural schematic view of a lower shell provided for an embodiment of the present application;

[0039] Figure 6 A top view of a lower shell provided for an embodiment of the present application;

[0040] Figure 7 A sectional view of a lower shell provided for an embodiment of the present application; Figure 6

[0041] A sectional view of a lower shell provided for an embodiment of the present application; Figure 8

[0042] A structural schematic view of an upper shell provided for an embodiment of the present application; Figure 9

[0043] A sectional view of an upper shell provided for an embodiment of the present application; Figure 10

[0044] A sectional view of an upper shell provided for an embodiment of the present application; Figure 11

[0045] A semi-sectional view of a noise reduction aerodynamic device provided for an embodiment of the present application; Figure 12

[0046] A semi-sectional view of a noise reduction aerodynamic device provided for an embodiment of the present application;

[0047] ​1 - housing; 11 - lower housing; 12 - upper housing; 13 - air inlet; 14 - air outlet; 15 - first chamber; 151 - first flow guide part; 1511 - first flow guide rib; 1512 - flow guide ring rib; 1513 - first flow guide cone; 152 - first flow-through area; 16 - second chamber; 161 - second flow guide part; 1611 - second flow guide rib; 1612 - third flow guide rib; 1613 - second flow guide cone; 162 - second flow-through area; 17 - air flow channel; 18 - sound attenuation chamber; 181 - first sound attenuation chamber; 182 - second sound attenuation chamber; 19 - partition plate;

[0048] 2 - fan bracket;

[0049] 3 - fan; 31 - fan inlet; 32 - fan outlet. DETAILED DESCRIPTION

[0050] In order to more clearly illustrate the overall concept of the present application, the following will be described in detail with reference to the accompanying drawings.

[0051] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, it will be apparent to one skilled in the art that the present application can be practiced without the specific details set forth in this description, and that the present application is not limited to the specific embodiments described here.

[0052] In addition, in the description of the present application, it should be understood that the terms "top", "bottom", "inner", "outer", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0053] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected, or it can be communicated; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above-mentioned terms in the present application can be understood according to the specific circumstances.

[0054] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. In the description of the present specification, the description referring to the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples.

[0055] The present application provides a noise reduction pneumatic device of a respirator. As shown in the embodiment, Figures 1-4 The noise reduction pneumatic device includes a housing 1. The housing 1 includes an inner cavity and an air inlet 13. The housing 1 is provided with a fan bracket 2 for fixing a fan 3. The fan bracket 2 divides the inner cavity into a first chamber 15 communicating with the air inlet 13 and a second chamber 16 communicating with a fan inlet 31. The first chamber 15 and the second chamber 16 are communicated through a plurality of airflow channels 17 arranged circumferentially around the fan 3. The fan bracket 2 has an installation cavity with an opening facing upward. The fan 3 is accommodated in the installation cavity, and the turbine of the fan is exposed to the installation cavity and extends into the second chamber 16. As shown in Figure 3 The airflow from the air inlet 13 to the fan inlet 31 is first introduced into the first chamber 15 through the air inlet 13, then enters the second chamber 16 through the plurality of airflow channels 17 arranged circumferentially around the fan 3, and finally enters the fan inlet 31.

[0056] The chaotic airflow entering through the air inlet 13 is buffered and slowed down in the first chamber 15, and is divided when entering the plurality of airflow channels 17 arranged circumferentially around the fan 3. The airflow is combed through the airflow channels 17, which can reduce impedance and eddy current, making the airflow smooth and smooth. After entering the second chamber 16, the airflow is slowed down again, and finally the airflow entering the fan inlet 31 has a low flow rate and is not prone to eddy current, resulting in low pneumatic noise at the fan inlet 31. Moreover, when the vibration noise generated by the rotation of the motor and the fan 3 blades propagates to the surrounding, the plurality of airflow channels 17 arranged circumferentially around the fan 3, as well as the first chamber 15 and the second chamber 16, can simultaneously act as a noise reduction cavity to block the propagation of vibration noise. In order to reduce the noise generated by the rotation of the fan 3 blades, a sound-absorbing material, such as a porous flexible foam material, is filled between the motor and the motor bracket 2 to buffer vibration and absorb noise, preventing noise from being conducted outward. Thus, the pneumatic noise reduction device of the present application can achieve noise reduction of the respirator and improve the user experience.

[0057] Specifically, in combination with Figures 5-7 As shown in the drawings, the shell 1 includes a lower shell 11 for supporting the fan support 2, and an air inlet 13 is arranged on the bottom wall of the lower shell 11. The shell 1 further includes an upper shell 12 arranged on the lower shell 11, and the fan inlet 31 is arranged upwardly, the fan outlet 32 is arranged on the side wall of the upper shell 12, and the air outlet 14 is also arranged on the side wall of the upper shell 12. Among them, the first chamber 15 is formed between the lower shell 11 and the fan

[0058] support 2, and the second chamber 16 is formed between the upper shell 12 and the fan 3 and the fan support 2. The lower shell 11 and the fan support 2 jointly form the airflow passage 17. Among them, a plurality of first airflow passages 17 are arranged along the circumference of the side wall of the lower shell 11, and the part of the fan support 2 above the first airflow passage 17 is provided with a second airflow passage 17 communicating with the first airflow passage 17. The first airflow passage 17 and the second airflow passage 17 jointly form the airflow passage 17 communicating the first chamber 15 and the second chamber 16, which can prolong the length of the airflow passage 17 and improve the effect of rectification.

[0059] As another implementation manner of the airflow passage 17, the lower shell 11 includes a bottom wall and a side wall extending in the axial direction, and a plurality of airflow passages 17 are arranged along the circumference of the side wall.

[0060] In this embodiment, the airflow passage 17 is arranged along the axial direction of the turbine of the fan 3 from the air inlet end to the air outlet end, that is, the airflow enters the second chamber 16 along the airflow passage 17 from bottom to top, the airflow flows more smoothly, the friction with the cavity wall of the airflow passage 17 is smaller, and the aerodynamic noise is not obvious.

[0061] As another implementation manner of the airflow passage 17, the airflow passage 17 is arranged in an inclined direction from the air inlet end to the air outlet end.

[0062] The inclined direction is the same as the rotation direction of the turbine of the fan 3. That is, the airflow passage 17 not only has the function of distributing and combing the airflow, but also can change the direction of the airflow, so that it flows along the rotation direction of the turbine of the fan 3, and reduces the aerodynamic noise of the fan inlet 31. Moreover, the airflow passage 17 arranged in an inclined direction can prolong the length of the passage and improve the rectification effect of the passage.

[0063] As another implementation manner of the airflow passage 17, the inclined direction is along the radial direction of the fan inlet 31 from the inside to the outside.

[0064] That is, when the airflow flows from bottom to top, the radial distance from the fan inlet 31 becomes farther and farther, and the gas flowing out of the air outlet end of the airflow passage 17 needs to pass through a longer flow channel to enter the fan inlet 31, which is beneficial to improve the rectification effect.

[0065] In the embodiment, the first chamber 15 is provided with a first flow guide part 151, the first flow guide part 151 includes a plurality of first flow guide ribs 1511 extending from the air inlet 13 to the airflow channel 17, the first flow guide ribs 1511 divide the first chamber 15 to form a plurality of first flow-through areas 152, and the first flow-through areas 152 are arranged one by one corresponding to the airflow channel 17. The airflow entering from the air inlet 13 is divided into different first flow-through areas 152 in the first chamber 15, and is guided and combed by the first flow guide ribs 1511, so that the airflow can enter the airflow channel 17 more smoothly, which is beneficial to improve the rectification effect and reduce the aerodynamic noise of the airflow and the cavity wall.

[0066] Further, the width of the first flow-through area 152 gradually increases in the direction from the air inlet 13 to the air inlet end of the airflow channel 17. The air inlet 13 is located at the center of the bottom wall of the lower shell 11, the first flow guide ribs 1511 are convex ribs protruding upward along the bottom wall of the lower shell 11, and the first flow guide ribs 1511 extend radially from the air inlet 13 to the periphery. At this time, the first flow-through area 152 is fan-shaped, and the air inlet end of the airflow channel 17 is arranged one by one corresponding to the first flow-through area 152.

[0067] Further, the first flow guide part 151 further includes a flow guide ring rib 1512 arranged circumferentially around the air inlet 13, the lower shell 11 is bent upward at the air inlet 13 to form the flow guide ring rib 1512, and the flow guide ring rib 1512 and the lower shell 11 have an arc transition surface therebetween, which guides the airflow to move towards the air inlet 13.

[0068] In the embodiment, the first flow guide part 151 is combined with the airflow channel 17 and the air inlet 13. Figures 8-9 As shown in the drawings, the second chamber 16 is provided with a second flow guide part 161, the second flow guide part 161 includes a plurality of second flow guide ribs 1611 arranged around the fan inlet 31 region, the second flow guide ribs 1611 extend from the airflow channel 17 to the fan inlet 31, the second flow guide ribs 1611 divide the fan inlet 31 region to form a plurality of second flow-through areas 162, and the second flow-through areas 162 are arranged one by one corresponding to the airflow channel 17. The airflow passing out of the airflow channel 17 is guided and combed again by the second flow guide ribs, so that the airflow entering the fan inlet 31 is more smooth and does not produce vortex, thereby reducing the aerodynamic noise of the fan inlet 31.

[0069] Further, the second flow guide part 161 further includes a third flow guide rib 1612 extending from the airflow channel 17 to the fan inlet 31, the third flow guide rib 1612 is arranged circumferentially around the fan inlet 31 and interlaces with the second flow guide rib 1611, and the third flow guide rib 1612 is arranged one by one corresponding to the airflow channel 17.

[0070] Further, in the radial direction of the fan inlet 31, the third flow guide rib 1612 is arranged outside the second flow guide rib 1611.

[0071] Furthermore, both the second guide rib 1611 and the third guide rib 1612 are provided with guide arc surfaces. The guide arc surfaces are curved in the direction away from the turbine rotation direction of the fan 3. The guiding direction of the guide arc surfaces is the same as the turbine rotation direction of the fan 3, so that the airflow enters the fan inlet 31 in the direction of the turbine rotation direction, avoiding turbulence and reducing the noise generated by the friction between the turbine blades and the air.

[0072] Furthermore, along the direction from the outlet of the airflow channel 17 toward the fan inlet 31, the width of the second flow area 162 gradually decreases, guiding the airflow to concentrate and flow toward the fan inlet 31.

[0073] In this embodiment, combined with Figures 10-11 As shown, the first guide section 151 also includes a first guide cone 1513 disposed towards the air inlet 13, the peripheral surface of the first guide cone 1513 being a concave arc surface. The first guide cone 1513 guides the airflow entering from the air inlet 13 to diffuse towards the surrounding airflow channels 17, preventing disordered airflow from entering the airflow channels 17.

[0074] Furthermore, the second guide section 161 also includes a second guide cone 1613 disposed towards the fan inlet 31, the circumferential surface of the second guide cone 1613 being a concave arc surface. The second guide cone 1613 guides the airflow to concentrate and flow towards the fan inlet 31.

[0075] In this embodiment, combined with Figure 12 As shown, the housing 1 also includes a silencing cavity 18 extending along the airflow direction of the fan outlet 32. Specifically, a portion of the lower housing 11 and the fan support 2 relative to the fan outlet 32 ​​continues to extend along the airflow direction, forming a silencing structure surrounding the fan outlet 32. This silencing structure is hollow, forming the silencing cavity 18. The silencing cavity 18 has an airflow outlet, allowing airflow. Furthermore, noise is continuously reflected and refracted against the cavity wall of the silencing cavity 18, reducing energy and thus helping to reduce noise at the fan outlet 32. Moreover, the greater the extension distance of the silencing cavity 18, the more significant the noise reduction effect. The length of the silencing cavity 18 can be rationally designed according to the installation space of the ventilator.

[0076] Specifically, the sound attenuation cavity 18 is provided with a partition 19, which can at least divide the sound attenuation cavity 18 into a first sound attenuation cavity 181 communicating with the fan outlet 32 and a second sound attenuation cavity 182 surrounding the first sound attenuation cavity 181. Specifically, the partition 19 is provided with a through hole communicating the second sound attenuation cavity 182 and the first sound attenuation cavity 181, which can be designed with different perforation rates, through hole depths and aperture sizes according to the noise value of the fan outlet 32. The noise passes through the through hole, the acoustic resistance increases, and the noise is absorbed. After the noise enters the second sound attenuation cavity 182, it continuously emits and refracts, and the noise energy gradually decreases. The second sound attenuation cavity 182 is filled with sound-absorbing material, which further plays a role in sound absorption and noise reduction.

[0077] Further, the second sound attenuation cavity 182 is filled with sound-absorbing material, such as porous flexible foam material, etc. The flexible foam material contains a large number of small interconnected pores inside, and the sound wave enters these pores and rubs with the material, further reducing the energy. Moreover, the flexible foam material is light in weight and will not increase the weight of the whole machine.

[0078] The places not mentioned in the application can be realized by using or referring to the existing technology.

[0079] Each embodiment in the specification is described in a progressive manner, and the same or similar parts between each embodiment can be referred to each other. Each embodiment mainly describes the difference from other embodiments.

[0080] The above only describes the embodiments of the application and is not used to limit the application. The application can be variously changed and modified by those skilled in the art. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the application shall be included in the scope of the claims of the application.

Claims

1. A noise reduction aerodynamic device of a breathing machine, comprising a housing, characterized in that, the housing comprises an inner cavity and an air inlet, and a fan support for fixing a fan is arranged in the housing, the fan support divides the inner cavity into a first chamber communicating with the air inlet and a second chamber communicating with a fan inlet, the first chamber and the second chamber are communicated through a plurality of airflow channels arranged circumferentially around the fan; a first flow guide part is arranged in the first chamber, the first flow guide part comprises a plurality of first flow guide ribs extending from the air inlet to the airflow channels, the first flow guide ribs divide the first chamber to form a plurality of first flow-through areas, and the first flow-through areas are arranged one by one corresponding to the airflow channels.

2. A noise reducing pneumatic device for a breathing machine as defined in claim 1, wherein, the housing comprises a lower housing for supporting the fan support, the air inlet is arranged on the bottom wall of the lower housing, and the lower housing is provided with the airflow channels; or, the lower housing and the fan support jointly form the airflow channels.

3. The noise reducing pneumatic apparatus of claim 1, wherein, the airflow channels are arranged in the axial direction of the fan turbine from the air inlet end to the air outlet end.

4. The noise reducing pneumatic apparatus of claim 1, wherein, the airflow channels are arranged in an inclined direction from the air inlet end to the air outlet end, and the inclined direction is the same as the turbine rotation direction of the fan; or, the inclined direction is from inside to outside along the radial direction of the fan inlet.

5. The noise reducing pneumatic apparatus of claim 1, wherein, the width of the first flow-through area gradually increases in the direction from the air inlet to the air inlet end of the airflow channel.

6. The noise reducing pneumatic apparatus of claim 1, wherein, the housing comprises a lower housing for supporting the fan support, the air inlet is arranged on the bottom wall of the lower housing, and the first flow guide part further comprises a flow guide ring rib arranged circumferentially along the air inlet.

7. The noise reducing pneumatic apparatus of claim 1, wherein, a second flow guide part is arranged in the second chamber, the second flow guide part comprises a plurality of second flow guide ribs arranged around the fan inlet area, the second flow guide ribs extend from the airflow channels to the fan inlet direction, the second flow guide ribs divide the fan inlet area to form a plurality of second flow-through areas, and the second flow-through areas are arranged one by one corresponding to the airflow channels.

8. A noise reducing pneumatic device for a breathing machine as defined in claim 7, wherein, the second flow guide part further comprises third flow guide ribs extending from the airflow channels to the fan inlet direction, the third flow guide ribs are arranged staggered with the second flow guide ribs in the circumferential direction of the fan inlet, and the third flow guide ribs are arranged one by one corresponding to the airflow channels.

9. A noise reducing pneumatic apparatus of a breathing machine according to claim 8, wherein, in the radial direction of the fan inlet, the third flow guide ribs are arranged outside the second flow guide ribs.

10. The noise reducing pneumatic apparatus of claim 8, wherein, the second flow guide ribs and the third flow guide ribs are both provided with flow guide arc surfaces, and the flow guide arc surfaces are curved away from the direction of the turbine rotation direction of the fan.

11. The noise reducing pneumatic apparatus of claim 7, wherein, the width of the second flow-through area gradually decreases in the direction from the air outlet end of the airflow channel to the fan inlet.

12. The noise reducing pneumatic apparatus of claim 7, wherein, the first flow guide part further comprises a first flow guide cone arranged towards the air inlet, and the peripheral surface of the first flow guide cone is an inner concave arc surface; and / or, the second flow guide part further comprises a second flow guide cone arranged towards the fan inlet, and the peripheral surface of the second flow guide cone is an inner concave arc surface.

13. The noise reducing pneumatic apparatus of claim 1, wherein, the housing further comprises a sound attenuation cavity arranged extending along the airflow direction of the fan outlet; a partition is arranged in the sound attenuation cavity, and the partition can at least divide the sound attenuation cavity to form a first sound attenuation cavity communicating with the fan outlet and a second sound attenuation cavity arranged around the first sound attenuation cavity.

14. A noise reducing pneumatic apparatus for a breathing machine as defined in claim 13, wherein The partition plate is provided with a through hole communicating the second sound damping cavity and the first sound damping cavity; and / or, The second sound damping cavity is filled with sound absorbing material.

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