1. The utility model provides a bucket type axial fan, includes outer bucket (11), mount pad (21), driving piece (31), impeller (32) and a plurality of stator (12), outer bucket (11) are equipped with air inlet end (13) and air-out end (14), install in mount pad (21) driving piece (31), the output shaft in driving piece (31) is installed in impeller (32), impeller (32) include a plurality of blades (33), impeller (32) and stator (12) all are located outer bucket (11), stator (12) are located one side that impeller (32) are close to air-out end (14), its characterized in that: the utility model discloses a stator, including stator (12), mount pad (21), stator (12) both ends respectively with outer bucket (11) inner wall and mount pad (21) fixed connection, a plurality of stator (12) encircle to set up in mount pad (21) periphery, and is a plurality of stator (12) are in order to distribute around mount pad (21) according to the unequal mode circumference of rotation angle, the angular difference psi ═ a ═ theta of arranging of stator (12), and wherein n is stator (12) quantity, and theta is the unequal interval angular difference of blade (33), and a is for being greater than 3 and being less than 6 proportionality coefficient, and theta is greater than 1 and is less than 10.

2. The barrel type axial flow fan according to claim 1, wherein: the top of the blade (33) is provided with an outer arc surface (34), the curvature gamma of the outer arc surface (34) is (R-0.8R)/4, wherein R is the radius of the impeller (32), and R is the height radius of the blade (33).

3. The barrel type axial flow fan according to claim 2, wherein: the middle of the blade (33) is provided with an inner arc surface (35), and the bending directions of the inner arc surface (35) and the outer arc surface (34) are opposite.

4. The barrel type axial flow fan according to claim 1, wherein: sawteeth (36) are arranged on the edge of one side of the blade (33) close to the guide vane (12).

5. The barrel type axial flow fan according to claim 1, wherein: the outer bucket (11) air inlet end (13) are equipped with bellmouth (15), bellmouth (15) are along keeping away from outer bucket (11) direction external diameter crescent.

6. The barrel type axial flow fan according to claim 1, wherein: the mounting seat (21) is cylindrical, and the driving piece (31) is fixedly mounted in the mounting seat (21).

7. The barrel type axial flow fan according to claim 1, wherein: outer bucket (11) fixed mounting has preceding screen panel (16) that is located air inlet end (13) department, outer bucket (11) fixed mounting has back screen panel (17) that is located air outlet end (14) department, preceding screen panel (16) and back screen panel (17) all are equipped with the gap, the gap width of back screen panel (17) is greater than the gap width of preceding screen panel (16).

8. The barrel type axial flow fan according to claim 1, wherein: the blades (33) and the guide vanes (12) are both arranged in an inclined mode, and the inclined direction of the guide vanes (12) is opposite to the inclined direction of the blades (33).

9. The barrel type axial flow fan according to claim 1, wherein: the driving piece (31) is provided with a slide way (22), and a locking piece (23) is arranged between the slide way (22) and the mounting seat (21).

Background

The axial flow fan mainly comprises an impeller, a motor, a fan casing and a support, and although the axial flow fan is simple in structure, the axial flow fan with the traditional structure cannot meet the higher and higher performance requirements of people on the axial flow fan along with social progress. The axial flow fan has a wide range of applications, and can be used for ventilation in factories, warehouses, offices, houses and other places. At present, people have requirements on movable and people-supplying axial fans that: (1) the air blowing distance of the fan is far when the fan runs, so that the air blowing requirement of people far away from the fan is met, the rotating speed of the fan is high, and the flow guiding and collecting effects of the fan are good; (2) the noise of the fan cannot be too high, so that people cannot feel uncomfortable; (3) the size of the whole fan cannot be overlarge, and the requirement of using the fan in a movable environment is met; (4) the fan power is little, and the energy efficiency ratio is high.

The existing fan can generally meet the requirements of air volume and air blowing distance, but the noise hardly meets the requirements, and the following methods are generally adopted in performance or structure: (1) in order to meet the requirements of air quantity and air blowing distance, the rotating speed of the fan is improved, but the noise and the power of the fan are greatly increased, the comfort level of people is reduced, and meanwhile, the energy consumption is very high; (2) the rotating speed is reduced, the diameter of the fan blade is increased, the requirements of air quantity and air blowing distance are met, but the size of the whole fan is increased, and the axial flow fan is not convenient to move, install and use; (3) the guide vanes are additionally arranged in front of or behind the wind wheel, so that the air flow rule in the wind shell is changed, but the noise can not be well reduced.

In order to improve the efficiency of the axial flow fan and reduce the working noise of the axial flow fan, the Chinese patent with publication number CN1793664 discloses a low-noise axial flow fan for a train air-conditioning condenser, which comprises a motor, fan blades, a casing, a bracket and a hub, wherein the cross section of the motor bracket is a streamlined body, the mounting position of the motor bracket deviates to the lower part of the casing and is far away from the fan blades, and the number of the bracket and the number of the blades are not multiples of each other. The fan blade adopts a new blade type designed according to a variable circulation flow pattern and a negative index to replace an original blade type designed according to an equal circulation amount, is an assembled adjustable blade angle type and can meet the requirements of different areas, the blades are arranged in an unequal distance mode with wide outer parts and narrow inner parts, and the included angle between the gravity center connecting line of each section of the blade and a radial straight line is less than or equal to 30 degrees and is in a sweepforward shape. The low-noise blade profile combined by the bending and sweeping of the outer width and the inner width and the high pressure coefficient and the fan blades arranged at unequal intervals are adopted to replace the existing equidistant radial symmetrical blades at the inlet, the characteristic of high efficiency at the outer diameter of the impeller can be fully utilized, the work adding amount is increased, the overlarge attack angle value near the blade root can be obviously reduced, and the blade angle of the blades is made adjustable, so that the blade can be used for trains to run in different areas and different seasons, and the energy is saved. The streamline motor support is properly far away from the inlet end of the blade, so that the eddy generated when the gas flows around can be reduced, and the influence on the work capacity of the impeller can be reduced.

The Chinese patent with publication number CN100445568C discloses a single-impeller axial flow fan of a traction motor brake cooling system, wherein a single-impeller structure with a front guide vane is used for replacing a two-stage impeller series operation structure, the technical scheme of the front guide vane, the impeller and a rear guide vane is adopted, a reverse guide vane is additionally arranged in front of the impeller, an axial support plate of the motor is changed into a streamline guide plate designed according to the airflow direction, the blade type design of the impeller is improved, and the blades are combined in a bending and sweeping shape with wide outside and narrow inside and are arranged in an unequal distance mode. When the fan rotates, the fan operation condition is improved, the fan efficiency is improved, the air flow separation is reduced, and the purposes of saving energy and reducing noise in a larger range are achieved by adopting a novel scheme of a streamline motor support plate, low-noise blades with wide outer width and narrow inner sweep and blades arranged at unequal intervals and a scheme of series operation of a secondary impeller by adopting a single-impeller structure additionally provided with front guide vanes. However, in the using process, the guide vanes also generate noise, so that the interference capability of the noise to people is large in the working process of the axial flow fan, and the using experience is influenced.

Disclosure of Invention

In order to solve the above technical problems, an object of the present invention is to provide a barrel-type axial flow fan, which includes an outer barrel, a mounting seat, a driving member, an impeller, and a plurality of guide vanes, and the barrel-type axial flow fan has an advantage of being capable of reducing noise intensity at a fundamental frequency and having a low noise interference capability to humans.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

the utility model provides a bucket type axial fan, includes outer bucket, mount pad, driving piece, impeller and a plurality of stator, outer bucket is equipped with air inlet end and air-out end, the driving piece is installed in the mount pad, impeller installation is in the output shaft of driving piece, the impeller includes a plurality of blades, impeller and stator all are located outer bucket, the stator is located one side that the impeller is close to the air-out end, the stator both ends respectively with outer bucket inner wall and mount pad fixed connection, it is a plurality of the stator encircles and sets up in the mount pad periphery, it is a plurality of the stator is in order to distribute according to the unequal mode circumference of rotation angle around the mount pad, the angle difference psi of arranging of stator is (360 °/n) -a theta, and wherein n is quantity, theta is the unequal pitch angle difference of blade, and a is for being greater than 3 and being less than 6 proportionality coefficient, and theta is greater than 1 and is less than 10. By such an arrangement: through with a plurality of stator with the unequal mode circumference distribution of angle, the noise frequency that produces on the different stator of angle is different to can prevent the appearance of noise harmonic, destroy the noise interference between a plurality of stator, make the frequency distribution of noise even, and can reduce the noise intensity of fundamental frequency department very effectively, thereby can effectively reduce the noise level, have the better advantage of sound quality, have the lower advantage of axial fan noise interference ability to people in the course of the work. The blades are arranged in a mode of non-equidistant angles, so that the noise peak value of the fundamental frequency of the blades can be effectively reduced, the sound energy of the fundamental frequency is distributed in a wider frequency band range, and the peak value of the fundamental frequency can be transferred to a low-frequency part, so that the interference capability of fan noise to people is greatly reduced, and the effect of improving the sound quality of the axial flow fan can be achieved. Can enough conveniently design the not equidistance stator, also can make the angle design of stator more reasonable, further reduce the noise peak value of blade fundamental frequency, improve axial fan sound quality's effect.

Preferably, the top of the blade is provided with an outer arc surface, and the curvature γ of the outer arc surface is (R-0.8R)/4, wherein R is the radius of the impeller and R is the radius of the blade height of the blade. By such an arrangement: the air can flow more smoothly on the surface of the blade, the exhaust flow can be improved, the noise generated when the blade rotates can be effectively reduced, the effect of reducing the noise is achieved, the interference capacity of the noise of the axial flow fan to people is reduced, and the effect of improving the sound quality of the axial flow fan is achieved.

Preferably, the middle part of the blade is provided with an inner cambered surface, and the bending direction of the inner cambered surface is opposite to that of the outer cambered surface. By such an arrangement: the efficiency ratio of the axial flow fan is improved, the effects of increasing the flow of the fan and reducing the power are achieved, the working performance of the fan is improved, air can flow more smoothly on the surface of the blade, the effect of reducing noise is achieved, the interference capacity of noise of the axial flow fan to people is reduced, and the effect of improving the sound quality of the axial flow fan is achieved.

Preferably, the edge of one side of the blade close to the guide vane is provided with sawteeth. By such an arrangement: the noise that effectively reduces the vortex and produce reaches the effect of noise reduction, reduces axial fan's noise to the interference ability of people, plays the effect that improves axial fan sound quality.

Preferably, the air inlet end of the outer barrel is provided with a bell mouth, and the outer diameter of the bell mouth is gradually increased along the direction far away from the outer barrel. By such an arrangement: the flow-collecting function is achieved, the blowing distance of the fan is longer, and the air quantity of a high-pressure area of the axial flow fan is improved.

Preferably, the mounting seat is cylindrical, and the driving piece is fixedly mounted in the mounting seat. By such an arrangement: the structure of the axial flow fan is more compact, and the external dimension of the axial flow fan can be reduced on the premise of ensuring that the working performance meets the requirements.

Preferably, the outer barrel is fixedly provided with a front mesh enclosure located at the air inlet end, the outer barrel is fixedly provided with a rear mesh enclosure located at the air outlet end, gaps are formed in the front mesh enclosure and the rear mesh enclosure, and the gap width of the rear mesh enclosure is larger than that of the front mesh enclosure. By such an arrangement: the effect of improving the security is played, reduces the influence of back screen panel to the air current, improves the flow and the distance that axial fan blows up, plays the effect that improves axial fan working property.

Preferably, the blades and the guide vanes are arranged in an inclined mode, and the inclined direction of the guide vanes is opposite to the inclined direction of the blades. By such an arrangement: the air is enabled to be close to the guide vane in the flowing direction, so that the resistance of the guide vane to the air is reduced, the working performance of the axial flow fan is improved, and the noise generated by the guide vane can be reduced.

Preferably, the driving piece is provided with a slide way, and a locking piece is arranged between the slide way and the mounting seat.

Compared with the prior art, the invention has the beneficial technical effects that:

1. through with a plurality of stator with the unequal mode circumference distribution of angle, the noise frequency that produces on the different stator of angle is different to can prevent the appearance of noise harmonic, destroy the noise interference between a plurality of stator, make the frequency distribution of noise even, and can reduce the noise intensity of fundamental frequency department very effectively, thereby can effectively reduce the noise level, have the better advantage of sound quality, have the lower advantage of axial fan noise interference ability to people in the course of the work.

2. The combined structure between blade and the stator can be further optimized, the interference noise of blade and stator is reduced, the base frequency noise is reduced, thereby the pneumatic efficiency of the axial flow fan is ensured while the noise is reduced, the effect of further reducing the noise interference capability of the axial flow fan is achieved, and the advantage of better sound quality of the axial flow fan is achieved.

3. In the process of rotating the blades, air can flow on the surface of the inner arc surface and can flow towards the middle of the inner arc surface by being guided by the inner arc surface, so that the effect of increasing the gas pressure at the inner arc surface is achieved, the energy efficiency ratio of the axial flow fan is improved, the effects of increasing the flow of the axial flow fan and reducing the power are achieved, the working performance of the axial flow fan is improved, the air can flow more smoothly on the surface of the blades, the effect of reducing noise is achieved, the interference capability of the noise of the axial flow fan on people is reduced, and the effect of improving the sound quality of the axial flow fan is achieved.

Drawings

Fig. 1 is a schematic structural view of a barrel-type axial flow fan according to an embodiment of the present invention;

FIG. 2 is a schematic structural view of a lock and a slide according to an embodiment of the present invention;

FIG. 3 is a schematic view of a connection structure of an outer barrel, a guide vane and a mounting seat according to an embodiment of the present invention;

fig. 4 is a schematic structural view of an impeller and blades according to an embodiment of the present invention.

Wherein, the technical characteristics that each reference numeral refers to are as follows:

11. an outer tub; 12. a guide vane; 13. an air inlet end; 14. an air outlet end; 15. a bell mouth; 16. a front mesh enclosure; 17. a rear net cover; 21. a mounting seat; 22. a slideway; 23. a locking member; 24. a nut; 31. a drive member; 32. an impeller; 33. a blade; 34. an outer arc surface; 35. an intrados surface; 36. and (4) saw teeth.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments, but the scope of the present invention is not limited to the following embodiments.

Referring to fig. 1 to 4, a barrel type axial flow fan includes an outer barrel 11, a mount 21, a driving member 31, an impeller 32, and a plurality of guide vanes 12.

Referring to fig. 1 and 2, the outer tub 11 is provided with an air inlet end 13 and an air outlet end 14, the air inlet end 13 of the outer tub 11 is provided with a bell mouth 15, and the outer diameter of the bell mouth 15 gradually increases along a direction away from the outer tub 11. The outer barrel 11 is fixedly provided with a front mesh enclosure 16 located at the air inlet end 13, the outer barrel 11 is fixedly provided with a rear mesh enclosure 17 located at the air outlet end 14, gaps are formed in the front mesh enclosure 16 and the rear mesh enclosure 17, and the width of the gap of the rear mesh enclosure 17 is larger than that of the gap of the front mesh enclosure 16. The driver 31 is mounted on the mounting seat 21, the mounting seat 21 is cylindrical, and the driver 31 is fixedly mounted in the mounting seat 21. The driving piece 31 is provided with a slide 22, a locking piece 23 is arranged between the slide 22 and the mounting seat 21, the locking piece 23 is a bolt penetrating through the mounting seat 21, a bolt head of the bolt is clamped into the slide 22, and the bolt is in threaded connection with a nut 24 clamped with the mounting seat 21.

Referring to fig. 1 and 3, the impeller 32 is mounted on the output shaft of the driving member 31, the impeller 32 includes a plurality of blades 33, the impeller 32 and the guide vanes 12 are both located in the outer barrel 11, the guide vanes 12 are located on one side of the impeller 32 close to the air outlet end 14, both ends of the guide vanes 12 are respectively fixedly connected to the inner wall of the outer barrel 11 and the mounting seat 21, the plurality of guide vanes 12 are circumferentially disposed on the periphery of the mounting seat 21, the plurality of guide vanes 12 are circumferentially distributed around the mounting seat 21 in an unequal manner of rotation angle, and included angles of the plurality of adjacent guide vanes 12 are gradually increased or decreased along a uniform circumferential direction (in this embodiment, included angles of the plurality of adjacent guide vanes 12 are gradually increased along the same circumferential direction). The arrangement angle difference ψ of the vanes 12 is (360 °/n) -a × θ, where n is the number of vanes 12, θ is the non-equidistant angle difference of the blades 33, a is greater than 3 and less than 6, and θ is greater than 1 ° and less than 10 °.

Referring to fig. 4, the top of the blade 33 is provided with an extrados surface 34, and the curvature γ of the extrados surface 34 is (R-0.8R)/4, where R is the radius of the impeller 32 and R is the radius of the blade height of the blade 33. The middle part of the blade 33 is provided with an inner cambered surface 35, and the bending direction of the inner cambered surface 35 is opposite to that of the outer cambered surface 34. The blade 33 is provided with serrations 36 at its edge near the guide vane 12. The blades 33 and the vanes 12 are both inclined, and the direction in which the vanes 12 are inclined is opposite to the direction in which the blades 33 are inclined.

The rotating impeller 32 drives the air to flow, so that the air flows along the direction from the air inlet end 13 to the air outlet end 14, and the air has a radial velocity in the flowing process. Through set up stator 12 in impeller 32 one side near air-out end 14, utilize stator 12 to adjust the radial velocity and the axial velocity of air current, turn into the radial pressure with radial velocity, reach the effect that improves air-out speed, play the effect that improves axial fan's work efficiency.

The rotating impeller 32 drives the air to flow in a direction from the air inlet end 13 to the air outlet end 14, and the air has a radial velocity in the flowing process, which may generate interference noise on the plurality of guide vanes 12. Through with a plurality of stator 12 with the unequal mode circumference distribution of angle, make the noise frequency that produces on the stator 12 that the angle is different to can prevent the appearance of noise harmonic, destroy the noise interference between a plurality of stator 12, make the frequency distribution of noise even, can effectively reduce the noise intensity of fundamental frequency department.

In the present embodiment, the number n of vanes 12 is 12, the difference θ between the equidistant angles of the blades 33 is 5, and the coefficient a is 5.4, so that the difference ψ between the equidistant angles of the equidistant vanes 12 is (360 °/12) -5.4 × 5 ° -3 °. By adopting the above-described non-equidistant angle design of the guide vanes 12, a better sound quality than equidistant distribution is obtained.

Through the calculation of the difference of the unequal angles and the noise simulation, the unequal angle guide vane 12 has a good noise reduction effect after adopting the following different groups of parameters:

a first set of non-equidistant angle vanes: when the number n of the guide vanes is 12, the unequal angle difference theta of the blades is 5, and the coefficient a is 5.4, the unequal angle difference psi is (360 °/12) -5.4 × 5 ° -3 °;

a second set of non-equidistant angle vanes: when the number n of the guide vanes is 12, the difference theta of the unequal angles of the blades is 5, and the coefficient a is 4.9, the difference psi is (360 °/12) -4.9 × 5 ° -5.5 °;

a third set of unequal-pitch angle vanes: when the number of vanes n is 12, the difference θ between the unequally spaced angles of the vanes is 5, and the coefficient a is 5.7, the difference ψ between the unequally spaced angles is (360 °/12) -5.7 × 5 ° -1.5 °.

The unequal-angle guide vanes 12 and the equidistant guide vanes 12 uniformly distributed on the circumference are subjected to software simulation test to obtain the following test data, and the specific test data are shown in table 1:

TABLE 1 noise spectra for 160Hz-2000Hz frequency bands for equidistant and non-equidistant angled vanes

In a software simulation test, the total noise values of the guide vanes with different equidistant angles are all smaller than the total noise values of the equidistant guide vanes, and the total noise value is the minimum when the different equidistant angles of the guide vanes are 3 degrees under the conditions of the same number of the guide vanes and the different equidistant angle difference of the same blades. The total noise value for the guide vanes with an unequal angle of 3 ° is 67dB, while the total noise value for the equidistant guide vanes under the same conditions is 69 dB.

In the simulation comparison test of the unequal-distance guide vanes 12 and the equidistant guide vanes 12, the frequencies with higher noise values, namely the frequencies of 500Hz and 800Hz, are obviously reduced at the frequencies with higher noise values originally after the unequal-distance guide vanes 12 are adopted, although the noise of the unequal-distance guide vanes 12 is higher than that of the equidistant guide vanes 12 in other partial frequency bands, the final obtained effect is that the total noise value of the unequal-distance guide vanes 12 is lower than that of the equidistant guide vanes 12. Therefore, simulation tests show that the overall noise value of the axial flow fan can be reduced by adopting the arrangement of the unequal-distance guide vanes 12, the noise at the fundamental frequency is reduced, and the sound quality of the axial flow fan can be improved.

After the guide vanes 12 are assembled on the axial flow fan, the axial flow fan is operated, the whole noise value of the guide vanes 12 which are distributed and installed equidistantly is measured to be 86.5d (B) A, the whole noise value of the guide vanes 12 which are installed in an unequal distribution mode with the angle difference of 3 degrees is changed to be 85.8d (B) A, and the whole noise value is reduced by 0.7d (B) A. By adopting the arrangement of the unequal-distance guide vanes 12, the noise of the whole axial flow fan can be reduced, the interference capability of the noise of the axial flow fan to people is greatly reduced, and the effect of improving the sound quality of the axial flow fan can be achieved.

The embodiment has the following advantages:

the driving member 31 drives the impeller 32 to rotate, and the rotating impeller 32 drives air to flow, so that the air flows along the direction from the air inlet end 13 to the air outlet end 14, and a blowing function is realized. When the impeller 32 drives the air to the guide vanes 12, the air flow has a radial velocity, and when the air flow with a certain radial velocity passes through the guide vanes 12, interference noise is generated on a plurality of guide vanes 12. Through with a plurality of stator 12 with the unequal mode circumference distribution of angle, the noise frequency that produces on the stator 12 that makes the angle difference is different to can prevent the appearance of noise harmonic, destroy the noise interference between a plurality of stator 12, make the frequency distribution of noise even, and can reduce the noise intensity of fundamental frequency department very effectively, thereby can effectively reduce the noise level, have the better advantage of sound quality, have the lower advantage of axial fan noise interference ability to people in the course of the work.

The blades 33 are arranged in a mode of non-equidistant angles, so that the noise peak value of the fundamental frequency of the blades 33 can be effectively reduced, the sound energy of the fundamental frequency is distributed in a wider frequency band range, and the peak value of the fundamental frequency can be transferred to a low-frequency part, so that the interference capability of fan noise to people is greatly reduced, and the effect of improving the sound quality of the axial flow fan can be achieved.

The radial speed of the airflow flowing to the guide vane 12 is generated by the rotation of the impeller 32, so that the unequal angle of the guide vane 12 is matched with the angle of the blade 33, the combined structure between the blade 33 and the guide vane 12 can be further optimized, the interference noise of the blade 33 and the guide vane 12 is reduced, the fundamental frequency noise is reduced, the aerodynamic efficiency of the axial flow fan is ensured, the effect of further reducing the noise interference capability of the axial flow fan is achieved, and the sound quality of the axial flow fan is better.

By setting the angle difference of the guide vane 12 to be psi ═ 360 °/n) -a ═ theta, the angle difference of the guide vane 12 with unequal distance can be obtained through calculation, the unequal distance guide vane 12 can be conveniently designed, the angle design of the guide vane 12 can be more reasonable, the noise peak value of the fundamental frequency of the blade 33 is further reduced, the sound energy of the fundamental frequency is distributed in a wider frequency band range, and the peak value of the fundamental frequency can be transferred to a low-frequency part, so that the interference capability of fan noise to people is greatly reduced, and the effect of improving the sound quality of the axial flow fan can be achieved.

By providing the extrados 34 at the top of the blade 33, the airflow is enabled to flow along the surface of the extrados 34. In the rotation process of the driving blade 33, the impeller 32 pushes air to flow by using the outer arc surface 34 and can play a role in pressurization, the air pressure out of the outer arc surface 34 is increased, the effect of increasing the gas pressure at the outer arc surface 34 can be achieved, the energy efficiency ratio of the axial flow fan is improved, the effects of increasing the flow rate and reducing the power of the axial flow fan are achieved, and the working performance of the axial flow fan is improved. Simultaneously, through the setting of extrados 34, can make the air more smooth flow on blade 33 surface, can not only improve the exhaust flow, can also effectively reduce the noise that blade 33 produced when rotating, play the effect of noise reduction, reduce axial fan's noise to the interference ability of people, play the effect that improves axial fan sound quality.

The curvature of the camber surface 34 is set to γ ═ R-0.8R)/4, so that the camber surface 34 with an appropriate curvature can be provided according to the blades 33 with different diameters, and the working performance of the blades 33 is ensured.

The outer curved surface 34 is curved outward of the blade 33, and the inner curved surface 35 is curved inward of the blade 33. Through the setting of intrados 35, at blade 33 pivoted in-process, the air can flow at the surface of intrados 35, and can flow to the middle part of intrados 35 through intrados 35 guide air, reach the effect of increase intrados 35 department gas pressure, improve axial fan's energy efficiency ratio, can increase the flow of fan, reduce the effect of power, improve the working property of fan, also can make the air flow more smoothly on blade 33 surface, play the effect of noise reduction, reduce axial fan's noise interference ability to the people, play the effect of improving axial fan sound quality.

During the rotation of the blade 33, the rear end of the blade 33 in the rotation direction generates a vortex to cause noise. The rear end of blade 33 is located the one side that is close to stator 12, sets up sawtooth 36 in the rear end of blade 33, makes blade 33 rear end unevenness to the vortex that makes blade 33 rear end produce offsets each other in the intersection, thereby effectively reduces the noise that the vortex produced, reaches the effect of noise reduction, reduces axial fan's noise to the interference ability of people, plays the effect that improves axial fan sound quality.

The horn mouth 15 is arranged at the air inlet end 13 of the outer barrel 11, so that the effect of collecting flow can be achieved, the blowing distance of the fan is further, and the air volume of a high-pressure area of the axial flow fan is improved.

The mounting seat 21 is set to be cylindrical, and the driving piece 31 is mounted in the mounting seat 21, so that the structure of the axial flow fan is more compact, and the external dimension of the axial flow fan can be reduced on the premise of ensuring that the working performance meets the requirement.

Through the setting of preceding screen panel 16 and back screen panel 17, prevent that people's finger from unexpected entering blade 33 department to prevent blade 33 at the rotation in-process with the staff fish tail, play the effect that improves the security. The front mesh enclosure 16 is close to the impeller 32 to prevent fingers of a person from passing through, and the blades 33 are further disposed between the rear mesh enclosure 17 and the impeller 32 to make the distance between the rear mesh enclosure 17 and the impeller 32 far, so that arms of the person need to be prevented from passing through. The gap of the rear mesh enclosure 17 is increased, the influence of the rear mesh enclosure 17 on air flow is reduced, the blowing flow and distance of the axial flow fan are increased, and the function of improving the working performance of the axial flow fan is achieved.

The air flow is driven by the rotation of the blades 33, so that the air has a radial velocity rotating in the direction of the rotation of the blades 33 in addition to a circumferential velocity toward the air outlet end 14 during the flow toward the blades 12. The inclination direction of the guide vane 12 is opposite to the inclination direction of the blade 33, so that the air is close to the inclination direction of the guide vane 12 in the flowing direction, the resistance of the guide vane 12 to the air is reduced, the working performance of the axial flow fan is improved, and the noise generated by the guide vane 12 can be reduced.

During the installation of the driving element 31, the locking element 23 is snapped into the slide 22, so that the driving element 31 can be positioned and the installation position of the driving element 31 can be adjusted in the direction of extension of the slide 22. After the driving member 31 is moved to a proper position, the nut 24 is screwed tightly, and the slide way 22 and the mounting seat 21 are kept in a tight abutting state through the pretightening force provided by the nut 24 and the screw, so that the slide way and the driving member 31 can be prevented from moving through friction force, and the function of locking the mounting position of the driving member 31 is realized.

Variations and modifications to the above-described embodiments may occur to those skilled in the art, which fall within the scope and spirit of the above description. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and variations of the present invention should fall within the scope of the claims of the present invention. Furthermore, although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.