CN115875313A - Fan subassembly and breathing machine that has it - Google Patents

Abstract

A fan assembly and a breathing machine with the same are disclosed, the fan assembly comprises a fan and a shell, the fan is provided with an air inlet, the shell is provided with an air inlet and an air inlet channel communicated with the air inlet and the air inlet, the air inlet channel comprises a first air channel, a second air channel and a third air channel which are sequentially communicated, the air inlet is exposed in the first air channel, the air inlet is exposed in the third air channel, the shell is also provided with a first throttling opening exposed towards the first air channel and the second air channel and a second throttling opening exposed towards the second air channel and the third air channel, and air flows in the first throttling opening and the second throttling opening respectively face different directions; the first throttling orifice which is suddenly contracted is utilized to conduct between the first air passage and the second air passage, and the second throttling orifice which is suddenly contracted is utilized to conduct between the second air passage and the third air passage, so that the acoustic impedance in the air inlet passage is suddenly changed, noise with specific frequency is silenced, silencing materials are not needed, and the use safety of a user is ensured.

Description

Fan subassembly and breathing machine that has it

Technical Field

The invention relates to the field of medical instruments, in particular to a fan assembly and a breathing machine with the same.

Background

The breathing machine is used as a medical device capable of replacing or assisting a patient to complete mechanical ventilation, can improve the breathing function, reduce the breathing function consumption and save the heart reserve capacity, and is mainly used in families, sleep treatment centers and some clinic hospitals. A common respirator includes a blower assembly and a water tank assembly, the blower assembly being configured to drive an airflow toward the water tank assembly and to mix with water vapor generated by the water tank assembly and deliver the mixture to a mask worn by a patient.

The fan of high-speed rotation in the fan subassembly is the gas source of breathing machine, and the fan can produce higher pneumatic noise at the operation in-process, and the noise directly influences patient's use experience through air current conduction and acoustic radiation. Fan subassembly among the prior art passes through the outside loss of air flue in order to reduce the fan noise, can set up amortization material in the air flue usually, for example the amortization is cotton, and amortization material can precipitate out harmful substance or take place the degradation in the use, and harmful substance passes through the air flue and inhales the internal back of user, has influenced user's safety in utilization.

Disclosure of Invention

The invention aims to provide a fan assembly with high safety and a breathing machine with the fan assembly.

To achieve one of the above objects, an embodiment of the present invention provides a fan assembly, including:

a fan having an air inlet;

the air conditioner comprises a shell, a fan and a fan, wherein the shell is provided with an air inlet and an air inlet passage for communicating the air inlet and the air inlet;

the air inlet air passage comprises a first air passage, a second air passage and a third air passage which are sequentially communicated, the air inlet is exposed in the first air passage, the air inlet is exposed in the third air passage, the shell further comprises a first throttling opening exposed towards the first air passage and the second air passage and a second throttling opening exposed towards the second air passage and the third air passage, and air flows in the first throttling opening and the second throttling opening face different directions respectively.

As a further improvement of the embodiment of the present invention, the fan assembly further includes a first partition plate disposed in the first air passage and a second partition plate disposed in the second air passage, the first partition plate and the second partition plate are both provided with a plurality of air vents, a first resonant cavity is formed between the first partition plate and the housing, and a second resonant cavity is formed between the second partition plate and the housing.

As a further improvement of the first embodiment of the present invention, the fan assembly further includes a third partition plate disposed in the third air passage, the third partition plate divides the third air passage into a first chamber and a second chamber, the third partition plate is provided with a plurality of air guide holes communicating the first chamber and the second chamber, the second throttle opening is exposed in the first chamber, and the air inlet is communicated with the second chamber.

As a further improvement of an embodiment of the present invention, the fan assembly further includes an air inlet pipe disposed in the second chamber, the air inlet pipe has a fixed end abutting against the air inlet and a free end departing from the fixed end, and the free end is spaced from the inner wall of the housing.

As a further improvement of an embodiment of the invention, the fan assembly further comprises a mounting member connecting the fan and the housing, the first air passage and the third air passage are formed on opposite sides of the mounting member, and the second air passage is located on the same side of the first air passage and the third air passage.

As a further improvement of the embodiment of the present invention, the first resonant cavity is located on a side of the first air duct facing away from the fan, and the second resonant cavity is located on a side of the second air duct facing away from the fan.

As a further improvement of the embodiment of the present invention, the first separator has a first flat plate portion in which the plurality of air-permeable holes are formed, the first flat plate portion being directed toward the air inlet, and the second separator has a second flat plate portion in which the plurality of air-permeable holes are formed, the plane of the second flat plate portion being perpendicular to the plane of the first flat plate portion.

As a further improvement of an embodiment of the present invention, the fan abuts against an inner wall of the mounting member and is at least partially exposed in the third air duct.

As a further improvement of the embodiment of the present invention, the housing further has a first pressure sampling port and a second pressure sampling port which are communicated with the intake air passage, the first pressure sampling port is communicated with the first air passage, the second pressure sampling port is communicated with the third air passage, and the first pressure sampling port and the second pressure sampling port are located on the same side of the housing.

In order to achieve the purpose of the invention, the invention also provides a respirator, which comprises the fan assembly.

Compared with the prior art, in the embodiment of the invention, the first air passage is communicated with the second air passage through the first suddenly-contracted throttling opening, and the second air passage is communicated with the third air passage through the second suddenly-contracted throttling opening, so that the acoustic impedance in the air inlet air passage is suddenly changed, noise with specific frequency is silenced, silencing materials are not needed, and the safety of a user in the using process is ensured.

Drawings

FIG. 1 is a perspective view of a fan assembly in a preferred embodiment of the present invention;

FIG. 2 isbase:Sub>A cross-sectional view taken at A-A of FIG. 1;

FIG. 3 is an exploded schematic view of the blower assembly of FIG. 1.

Detailed Description

The present invention will be described in detail below with reference to specific embodiments shown in the drawings. These embodiments are not intended to limit the present invention, and structural, methodological, or functional changes made by those skilled in the art according to these embodiments are included in the scope of the present invention.

It will be understood that terms such as "upper," "lower," "outer," "inner," and the like, used herein to denote relative spatial positions, are used for ease of description to describe one element or feature's relationship to another element or feature as illustrated in the figures. The spatially relative positional terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures.

Moreover, it will be understood that, although the terms first, second, etc. may be used herein to describe various elements or structures, these described elements should not be limited by the above terms. The above terms are only used to distinguish these descriptive objects from each other. For example, the first orifice may be referred to as the second orifice and likewise the second orifice may be referred to as the first orifice without departing from the scope of the application.

Referring to fig. 1 to 3, a preferred embodiment of the present invention provides a blower assembly for a domestic ventilator, typically for use in conjunction with a water tank assembly, for driving airflow to the water tank assembly and for delivery to a user-worn facepiece in admixture with water vapor generated by the water tank assembly. Moreover, the respirator is mainly used for treating snoring and sleep apnea syndrome, so the requirement on silence is high.

Specifically, referring to fig. 1 and 2 in combination, a fan assembly includes a fan 10 and a housing 20. In this embodiment, the blower 10 is connected to the housing 20 and is mounted to the ventilator by the housing 20.

Specifically, the fan 10 has an air inlet 11, and the housing 20 has an air inlet 21 and an air inlet duct communicating the air inlet 21 and the air inlet 11. In this embodiment, the fan further has an exhaust port, and after the air outside the housing 20 enters the air inlet duct through the air inlet 21, the air flows to the air inlet 11 through the air inlet duct, enters the fan 10 through the air inlet 11, and finally is discharged out of the fan 10 through the exhaust port. Thus, the noise generated by the fan 10 escapes the fan assembly in the opposite direction to the airflow, i.e., through the inlet air duct.

Specifically, the intake air passage includes a first air passage 221, a second air passage 222 and a third air passage 223 which are sequentially communicated, the air inlet 11 is exposed in the first air passage 221, and the air inlet 21 is exposed in the third air passage 223. In this embodiment, part of the noise generated by the fan 10 passes through the first air duct 221, the second air duct 222 and the third air duct 223 in sequence, and finally escapes from the air inlet 21 to the outside of the housing 20.

Further, the housing 20 has a first orifice 23 exposed to the first air passage 221 and the second air passage 222 and a second orifice 24 exposed to the second air passage 222 and the third air passage 223. In the present embodiment, the first orifice 23 and the second orifice 24 achieve throttling, i.e., reduce the amount of gas passing, by changing the cross-sectional area of the gas passage in the intake gas passage. Therefore, the first orifice 23 forms a first expanding chamber silencing structure at the connection between the first air passage 221 and the second air passage 222, i.e. when the sound wave enters the next chamber from the previous chamber, part of the sound wave is reflected due to the sudden change of the acoustic impedance. When the reflected sound wave is equal to the original sound wave in size and opposite in direction, the reflected sound wave interferes with the original sound wave to offset, and noise of specific frequency is silenced. Likewise, the second orifice 24 also forms a second expansion chamber silencing structure at the communication between the second gas passage 222 and the third gas passage 223.

Further, the air flows in the first orifice 23 and the second orifice 24 are directed in different directions. In this embodiment, because first throttle orifice 23 and second throttle orifice 24 all communicate in second air flue 222, including the air current direction difference in first throttle orifice 23 and the second throttle orifice 24, make the air current direction of inflow and outflow second air flue 222 different, thereby make the fan noise when outwards dissipating through the air intake air flue, increased the time of detaining in second air flue 222, increased the time that the noise carried out the amortization in two expansion chamber sound-deadening structure departments then, the effect of making an uproar is fallen in the amortization has been promoted.

The first air passage 221 is communicated with the second air passage 222 through the first throttle orifice 23 which is suddenly contracted, and the second air passage 222 is communicated with the third air passage 223 through the second throttle orifice 23 which is suddenly contracted, so that the acoustic impedance in the air inlet passage is suddenly changed, noise with specific frequency is silenced, silencing materials are not needed, the safety of a user in the using process is ensured, and the using cost of the respirator is reduced.

Further, the fan assembly further includes a first partition plate 30 disposed in the first air duct 221 and a second partition plate 40 disposed in the second air duct 222, and a plurality of air holes 50 are disposed on both the first partition plate 30 and the second partition plate 40. In this embodiment, the plurality of ventilation holes 50 are uniformly arranged in a matrix on the first and second partition plates 30 and 40. The aperture size of the air holes 50 is set to be between 1mm and 30mm, and the number of the air holes 50 on the first partition plate 30 or the second partition plate 40 is set to be between 1 and 300.

Further, a first resonant cavity 31 is formed between the first partition 30 and the housing 20. In this embodiment, the first resonant cavity 31 is a closed cavity formed by the first partition 30 and the housing 20, and the first resonant cavity 31 is communicated with the first air passage 221 through a plurality of air vents 50. When the sound wave in the first air channel 221 is incident on the first partition board 30, because of the sudden change of the acoustic impedance, part of the sound wave is reflected back to interfere and cancel with the original sound wave; another part of the sound waves enter the first resonant cavity 31 through the air holes 50 to cause the air column in the air holes 50 to vibrate, and the damping of the vibration converts part of the sound energy into heat energy to be consumed, thereby weakening the sound wave energy propagated outwards.

Further, a second resonant cavity 41 is formed between the second partition 40 and the housing 20. In the present embodiment, similarly, the second resonant cavity 41 is a closed cavity formed by the second partition plate 40 and the casing 20, and the second resonant cavity 41 is communicated with the second air channel 222 through the plurality of air vents 50. When the sound wave in the second air passage 222 is incident on the second partition plate 40, part of the sound wave is reflected back due to the sudden change of the acoustic impedance, and the sound wave interferes and cancels with the original sound wave; another part of the sound waves enter the second resonant cavity 41 through the air holes 50, causing the air column in the air holes 50 to vibrate, and the damping of the vibration converts part of the sound energy into heat energy to be consumed, thereby weakening the sound wave energy propagating outwards.

Further, referring to fig. 3, the blower assembly further includes a third partition plate 60 disposed in the third air duct 223, the third partition plate 60 divides the third air duct 223 into a first cavity 223a and a second cavity 223b, and the third partition plate 60 is provided with a plurality of air vents 61 communicating the first cavity 223a with the second cavity 223b. In this embodiment, the plurality of air holes 61 are uniformly arranged in a matrix on the third separator 60. The pore size of the air-guide holes 61 is set to be between 1mm and 30mm, and the number of the air-guide holes 61 on the third separator 60 is set to be between 1 and 300.

The third partition plate 60 is arranged between the first cavity 223a and the second cavity 223b and is communicated with each other through the air guide holes 61, when the noise sound wave propagates from the first cavity 223a to the second cavity 223b, the noise sound wave is realized through the air guide holes 61 on the third partition plate 60, at this time, the frequency spectrum of the noise shifts to a high frequency domain, so that the audible sound component is reduced, and a micropore silencing structure is formed.

In addition, after the plurality of expansion cavity silencing structures, the resonance cavity and the micropore silencing structure are combined, the outward loss of fan noise is reduced, and the loss of the noise in the transmission process is improved, so that a better silencing effect is realized, and the noise reduction level of the fan assembly is integrally improved.

Specifically, the second restriction 24 is exposed in the first chamber 223a, and the intake vent 21 is communicated with the second chamber 223b. In this embodiment, the air outside the housing 20 flows into the second chamber 223b through the air inlet 21, the air in the second chamber 223b flows into the first chamber 223a through the air guide hole 61, and the air in the first chamber 223a flows into the second air passage 222 through the second throttle 24.

Specifically, the housing 20 includes a first shell 20a forming the air inlet 21 and a second shell 20b connected to the first shell 20a, and a gasket is disposed between the first shell 20a and the second shell 20b for sealing. The third partition 60 is preferably co-molded directly with the housing 20, thereby reducing manufacturing costs. A part of the third partition 60 is formed together with the first case 20a, and the other part of the third partition 60 is formed together with the second case 20b, and the first case 20a and the second case 20b are assembled to form the entire third partition 60.

Further, with continued reference to fig. 3, the blower assembly further includes an air inlet pipe 70 disposed in the second chamber 223b, wherein the air inlet pipe 70 has a fixed end abutting against the air inlet 21 and a free end departing from the fixed end, and the free end is spaced apart from the inner wall of the housing 20. In this embodiment, the air outside the housing 20 enters the air inlet duct 70 through the air inlet 21, and then is introduced into the third air duct 223 through the air inlet duct 70, i.e., into the second chamber 223b. The cross section of the air inlet duct 70 is preferably a circular tube, and the cross section of the air inlet duct 70 is isosceles trapezoid, i.e., the aperture size of the air inlet duct 70 is gradually reduced from the fixed end toward the free end.

The air inlet pipe 70 is positioned in the second chamber 223b in the third air passage 223 and extends towards the inside of the second chamber 223b after being butted with the air inlet 21, the free end of the air inlet pipe 70 and the shell 20 are arranged at intervals, the sound waves flowing from the third air passage 223 to the air inlet 21 are weakened, and the noise reduction and silencing effects of the air passages are realized.

Specifically, as shown in fig. 3, the air inlet duct 70 is integrally formed with the first housing 20a, extends toward the second housing 20b after being disposed in the second cavity 223b, and is spaced apart from the second housing 20 b. The axial length of the air inlet duct 70 is less than or equal to 100mm.

Further, with continued reference to fig. 2, the blower assembly further includes a mounting member 80 for connecting the blower 10 to the housing 20, the first air passage 221 and the third air passage 223 are formed on opposite sides of the mounting member 80, and the second air passage 222 is located on the same side of the first air passage 221 and the third air passage 223.

In this embodiment, the first throttle 23 and the second throttle 24 are arranged along the axial direction of the fan wheel. When the first throttle 23 connects the first air passage 221 and the second air passage 222, the flow direction of the gas in the two air passages is changed, so that the flow direction of the gas in the first air passage 221 and the flow direction of the gas in the second air passage 222 form a certain angle, and the included angle is preferably 90 degrees. Therefore, the staying time of the fan noise at the first resonance cavity 31 and the first throttling port 23 is increased, so that the noise reduction time of the resonance cavity and the expansion cavity noise reduction structure is increased.

Similarly, when the second restriction 24 connects the second air passage 222 and the third air passage 223, the flow direction of the air in the two air passages is changed, so that the flow direction of the air in the second air passage 222 and the flow direction of the air in the third air passage 223 form a certain angle, and the included angle is preferably 90 °. Therefore, the time of the fan noise staying at the second resonant cavity 41, the second choke 24 and the micropore sound attenuation structure is increased, so that the sound attenuation and noise reduction time of the resonant cavity, the expansion cavity sound attenuation structure and the micropore sound attenuation structure is increased.

Further, the first resonance cavity 31 is located on a side of the first air duct 221 facing away from the fan 10, and the second resonance cavity 41 is located on a side of the second air duct 222 facing away from the fan 10. In this embodiment, the second cavity 223b is located on a side of the first cavity 223a facing away from the blower 10. As shown in the airflow diagram in fig. 2, when the fan 10 extracts the air outside the casing 20, since the first cavity 223a is directly communicated with the second air duct 222 through the second orifice 24, and the second air duct 222 is directly communicated with the first air duct 221 through the first orifice 23, the airflow turbulence in the intake air duct is reduced, so that the noise reduction and silencing are satisfied, and the air outside the casing 20 is ensured to smoothly enter the fan 10.

Specifically, the first partition plate 30 has a first flat plate portion 32 in which a plurality of ventilation holes 50 are formed, and the first flat plate portion 32 faces the air inlet 11. In this embodiment, the first partition 30 is a flat plate structure and is connected between the first shell 20a and the second shell 20b in an inserting manner without a fixing member. Because the negative pressure at the air inlet 11 is large, the air flow amount is large, and then noise is generated, so that the plurality of air holes 50 on the first flat plate part 32 are opposite to the air inlet 11, the noise source can be closer, noise is reduced at the noise source, and further propagation of noise is avoided. Moreover, the axis of the air hole 50 on the first flat plate part 32 is parallel to the axis of the fan impeller, so that noise sound waves directly enter the first resonant cavity 31 along the axis of the air hole 50, and the transmission of noise is avoided.

Further, the second separator 40 has a second flat plate portion 42 having a plurality of ventilation holes 50 formed therein, and the plane of the second flat plate portion 42 is perpendicular to the plane of the first flat plate portion 32. In this embodiment, the entire second partition 40 is "n" shaped and is connected between the first shell 20a and the second shell 20b by a pin positioning manner without a fixing member. The second flat plate 42 faces the side of the fan 10, and the axis of the ventilation hole 50 on the second flat plate 42 is perpendicular to the axis of the fan wheel, so that the side of the fan 10 is reduced in noise.

The third partition 60 has a third flat plate 62 forming the air holes 61, and the third flat plate 62 is disposed on a plane parallel to the first flat plate 32 and opposite to both sides of the mounting member 80, so as to surround the fan 10 for noise reduction.

Further, the fan 10 abuts against the inner wall of the mounting member 80. In this embodiment, the mounting member 50 is made of an elastic material, and the mounting member 80 elastically abuts against the fan 10, so that the fan 10 is suspended in the casing 20 to block vibration generated in the operation process of the fan 10, thereby reducing noise generated in the operation process of the fan 10. The mounting member 80 is preferably a silicone material having a shore hardness of 30-70.

Further, at least a portion of the blower 10 is exposed to the third air duct 223. In this embodiment, the motor portion of the fan 10 is exposed in the first cavity 223a in the third air duct 223 of the docking hole 54, and the fan 10 is cooled by the external air flowing in from the air inlet 21, so that the service life of the fan 10 is prolonged.

In addition, a part of the fan 10 is located in the third air duct 223, that is, the motor part of the fan 10 is located in the third air duct 223, and noise reduction is performed by the air inlet pipe 70 and the third partition plate 60 in the third air duct 223. The other parts of the fan 10 are located in the first air duct 221, and the noise reduction is realized by using the first resonant cavity 31 in the first air duct 221, so that the noise reduction and silencing of the noise generated by the fan 10 can be ensured.

Further, the housing 20 further has a first pressure sampling port 25 and a second pressure sampling port 26 communicated with the intake air passage, the first pressure sampling port 25 is communicated with the first air passage 221, and the second pressure sampling port 26 is communicated with the third air passage 223. In this embodiment, the air vent 61 in the third partition 60 can communicate the first pressure generating port 25 and the second pressure generating port 26. The third partition 60 having the plurality of gas holes 61 can block the gas flow in the intake air passage, thereby reducing the propagation sectional area of the acoustic energy. The first pressure sampling port 25 and the second pressure sampling port 26 are respectively located at the upstream and downstream of the third partition plate 60 with the plurality of air guide holes 61, and because the flow area of the third partition plate 60 with the plurality of air guide holes 61 is constant, the flow value in the air inlet passage can be calculated and obtained by obtaining the pressure difference between the first pressure sampling port 25 and the second pressure sampling port 26 according to the bernoulli principle, and the user can adjust the rotating speed of the fan 10 to adjust the flow value according to the requirement. Through setting up two pressure ports respectively in different chambeies, improved the coverage route of pressure section in the cavity to flow monitoring's accuracy has been improved.

Further, the first pressure generating port 25 and the second pressure generating port 26 are located on the same side of the casing 20. In this embodiment, as shown in fig. 1, the first pressure sampling port 25 and the second pressure sampling port 26 are located on the same side of the casing 20 and are arranged along the axial direction of the impeller of the fan 10, so that the first pressure sampling port 25 and the second pressure sampling port 26 are arranged in close proximity to each other, and thus the distance between the first pressure sampling port 25 and the second pressure sampling port 26 is reduced, which is convenient for a user to install pressure sensors at the first pressure sampling port 25 and the second pressure sampling port 26 and perform flow monitoring.

Specifically, the first pressure generating port 25 and the second pressure generating port 26 are both provided on the second casing 20 b. The second pressure generating port 26 communicates with the second chamber 223b.

According to another aspect of the invention, there is also provided a ventilator provided with a fan assembly according to the invention. The exhaust port of the blower 10 is communicated with the output pipeline of the respirator, and the output pipeline of the respirator is butted with the air outlet of the mounting piece.

It should be understood that although the present description refers to embodiments, not every embodiment contains only a single technical solution, and such description is for clarity only, and those skilled in the art should make the description as a whole, and the technical solutions in the embodiments can also be combined appropriately to form other embodiments understood by those skilled in the art.

The above-listed detailed description is only a specific description of a possible embodiment of the present invention, and they are not intended to limit the scope of the present invention, and equivalent embodiments or modifications made without departing from the technical spirit of the present invention should be included in the scope of the present invention.

Claims (10)

1. A fan assembly, comprising:

a fan having an air inlet;

the air conditioner comprises a shell, a fan and a fan, wherein the shell is provided with an air inlet and an air inlet passage for communicating the air inlet and the air inlet;

the air inlet and outlet device is characterized in that the air inlet air passage comprises a first air passage, a second air passage and a third air passage which are sequentially communicated, the air inlet is exposed in the first air passage, the air inlet is exposed in the third air passage, the shell is further provided with a first throttling opening exposed towards the first air passage and the second air passage and a second throttling opening exposed towards the second air passage and the third air passage, and air flows in the first throttling opening and the second throttling opening respectively face different directions.

2. The fan assembly of claim 1 further comprising a first baffle disposed in the first air path and a second baffle disposed in the second air path, wherein the first baffle and the second baffle each have a plurality of air holes formed therein, a first resonant cavity is formed between the first baffle and the housing, and a second resonant cavity is formed between the second baffle and the housing.

3. The fan assembly of claim 1 further comprising a third baffle disposed in the third air path, the third baffle dividing the third air path into a first chamber and a second chamber, the third baffle having a plurality of air vents communicating the first chamber with the second chamber, the second orifice exposed in the first chamber, and the air inlet communicating with the second chamber.

4. The fan assembly of claim 3 further comprising an air inlet duct disposed within the second chamber, the air inlet duct having a fixed end abutting the air inlet and a free end facing away from the fixed end, the free end being spaced from the inner wall of the housing.

5. The fan assembly of claim 1 further comprising a mount connecting the fan to the housing, the first and third air passages being formed on opposite sides of the mount, the second air passage being located on a same side of the first and third air passages.

6. The fan assembly of claim 2 wherein the first resonant cavity is located on a side of the first air path facing away from the fan and the second resonant cavity is located on a side of the second air path facing away from the fan.

7. The fan assembly of claim 2 wherein the first baffle has a first plate portion defining the plurality of air-permeable openings, the first plate portion facing the air inlet, and the second baffle has a second plate portion defining the plurality of air-permeable openings, the second plate portion being in a plane perpendicular to the plane of the first plate portion.

8. The fan assembly of claim 5 wherein the fan abuts an inner wall of the mounting member and is at least partially exposed within the third air path.

9. The fan assembly of claim 1, wherein the housing further comprises a first pressure sampling port and a second pressure sampling port in communication with the inlet air path, the first pressure sampling port is in communication with the first air path, the second pressure sampling port is in communication with the third air path, and the first pressure sampling port and the second pressure sampling port are located on the same side of the housing.

10. A ventilator comprising a fan assembly as claimed in any one of claims 1 to 9.

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