A high-speed, low-noise centrifugal fan with air filtering effect

Abstract

The present invention belongs to the technical field of sanitation machinery, and in particular, relates to a high-speed, low-noise centrifugal fan with air filtering effect, including a fan volute, a fan impeller is installed inside the fan volute, the fan impeller includes a front disc, a middle disc and a plurality of fan blades, the plurality of fan blades are located between the front disc and the middle disc, the front disc and the middle disc and the space between two adjacent fan blades constitute the flow channel of the fan impeller, and a drive motor is installed on the rear side of the fan volute. The high-speed, low-noise centrifugal fan with air filtering effect of the present invention has made a new plan in terms of blade shape, blade structure, volute tongue and the overall structure of the fan, and in particular, a cyclone separator is added to the fan air inlet, so as to quickly separate and purify the high-speed gas entering the fan volute, and settle and separate the dust and other garbage in the gas, thereby improving the air quality discharged into the atmosphere from the fan outlet and reducing the secondary pollution of sanitation operations.

Description

Technical Field

[0001] The invention belongs to the technical field of sanitation machinery, and in particular relates to a high-speed and low-noise centrifugal fan with air filtering effect. Background Art

[0002] The technical route of domestic new energy vehicles is mainly pure electric, and the urban sanitation market is the main application field of pure electric commercial vehicles, among which washing and sweeping vehicles, road sweeping vehicles, and dry sweeping vehicles are the categories with the largest sales of urban sanitation vehicles. This type of suction and sweeping sanitation equipment cannot be separated from the configuration of the pneumatic conveying system, and the source of pneumatic conveying is a high-performance centrifugal fan, which means that the driving source of the fan has also been changed from the original fuel power to the motor.

[0003] High-efficiency and high-flow centrifugal fans are used in the sanitation machinery and equipment industry to provide air sources for pneumatic conveying, and the technology is relatively mature. The industry mainly uses traditional 9-26 type fans to match the flow and total pressure requirements. In recent years, with the continuous improvement of energy-saving and environmental protection requirements, although the performance indicators of fans supporting sanitation products have also been increasing, the existing ventilation products still have problems such as low static pressure when the flow is small, low fan efficiency, and the curved blades of the fan are easy to accumulate dust and difficult to clean, and high noise during operation; in particular, under the pneumatic conveying conditions of sanitation washing and sweeping vehicles, the fan is required to have a wider use characteristic, that is, within a wider speed range, it has better power, pressure, flow, and efficiency characteristics, and with the increase of the fan speed, not only the air volume increases significantly, but also the static pressure increases in a certain proportion, but the efficiency of the fan has been maintained at a higher level, so that the fan performance parameters can be well matched with the use requirements. These are the places where existing fans are difficult to meet the requirements of society and users.

[0004] The fan generates airflow through the fan impeller, which includes an arc-shaped front disk and a rear disk, with multiple fan blades evenly distributed on the front and rear disks. The casing reduces wind resistance and recovers static pressure. However, due to the existing fan impeller form and fan volute structure, such a fan is not conducive to the generation of wind pressure. The airflow easily disappears in the casing as the fan impeller rotates, resulting in low flow, high power consumption and low static pressure of the existing fan, which reduces the use efficiency and increases the user's use cost.

[0005] Therefore, it is necessary to invent a high-speed, low-noise centrifugal fan with air filtering effect to solve the above problems. Summary of the invention

[0006] In view of the above problems, the present invention provides a high-speed, low-noise centrifugal fan with air filtering effect to solve the problems raised in the above background technology.

[0007] To achieve the above-mentioned purpose, the present invention provides the following technical solution: a high-speed and low-noise centrifugal fan with air filtering effect, comprising a fan volute, a fan impeller is installed inside the fan volute, and the fan impeller comprises a front disk, a middle disk and a plurality of fan blades, and the plurality of fan blades are located between the front disk and the middle disk, and the space between the front disk and the middle disk and two adjacent fan blades constitutes a flow channel of the fan impeller. A drive motor is installed on the rear side of the fan volute, and the output shaft of the drive motor rotates and penetrates and is plugged into the center of the circle on the rear side of the fan volute, and the output end of the drive motor is drivingly connected to the fan impeller, an air inlet is provided on the front side of the fan volute, an air inlet pipe is plugged into the air inlet, and a cyclone separator is connected to the front end of the air inlet pipe, and the cyclone separator comprises a separator outer cylinder, and a flange is fixedly connected to the rear end of the separator outer cylinder, and the flange is fixed to the front end of the air inlet pipe by bolts The separator is connected together, and a coaxial separator inner cylinder is arranged on the inner side of the separator outer cylinder. The wall of the front half of the separator inner cylinder is inclined toward the direction close to the separator outer cylinder, and the separator inner cylinder is fixedly connected to the front end of the separator outer cylinder, and the rear end of the separator inner cylinder is fixedly connected to the flange, and the gap between the separator outer cylinder and the separator inner cylinder forms a dust gathering area, and an annular separation inverted cone is fixedly connected to the inner wall of the rear end of the separator inner cylinder, and the diameter of the separation inverted cone gradually increases from front to back, and a plurality of waist-shaped holes are annularly distributed on the separator inner cylinder, and the waist-shaped holes are opposite to the area where the separation inverted cone is located, and a dust discharge pipe is connected to the bottom of the separator outer cylinder, and a central guide hub is arranged at the axis center of the front end of the separator inner cylinder, and guide spiral blades are fixedly connected to the central guide hub around the central guide hub, and the guide spiral blades are fixedly connected to the inner wall of the separator inner cylinder on the side away from the central guide hub.

[0008] Furthermore, the fan impeller can be manufactured by welding or casting, the fan blade is designed backward, the outlet angle of the fan blade is 28.6°, the inlet angle of the fan blade is 14.5°, the length of the fan blade is L, and L=kx(R2-R1), wherein R1 is the inner diameter of the fan blade 203, R2 is the outer diameter of the fan blade, k is the empirical coefficient, and k is greater than 2.5.

[0009] Furthermore, the pressure-bearing surface and the non-pressure-bearing surface of the fan blade are both formed by fitting multiple curves, and the fan blade is a through-hole structure.

[0010] Furthermore, the air inlet pipe is connected to the air inlet at the front end of the fan impeller by means of a sleeve-overlapping manner, the single-side gap between the two is 0.3 mm, and the length of the sleeve-overlapping part reaches 5% of the fan impeller inlet diameter.

[0011] Furthermore, the volute tongue portion of the fan volute adopts a multi-segment combination type, and the specific combination form is: a combined volute tongue of a logarithmic spiral segment + a tangent straight line segment + an Archimedean spiral segment.

[0012] Furthermore, there are three guide spiral blades, and the three guide spiral blades are evenly distributed in the separator inner tube, and the guide spiral blades are connected to the central guide hub by welding.

[0013] Furthermore, a filter assembly is provided at the front end of the separation inverted cone, and the filter assembly includes a filter cover, the filter cover is detachably mounted on the front end of the separation inverted cone, and the rear end opening of the filter cover is sleeved on the outside of the separation inverted cone, the front end of the filter cover is vertically rotated and inserted with a rotating shaft, a plurality of fan blades are annularly distributed on the front end surface of the rotating shaft, a fixing ring is rotatably sleeved at a position close to the rear end of the rotating shaft, a plurality of fixing rods are fixedly connected between the side surface of the fixing ring and the inner side of the filter cover, a plurality of cleaning rods are annularly distributed on the outer side of the filter cover, the cleaning rods are close to the outer side of the filter cover, and bristles are evenly arranged on the side of the cleaning rod opposite to the surface of the filter cover, one end of the cleaning rod close to the rotating shaft is hinged to the rotating shaft through a torsion spring, the free end of the cleaning rod is rotatably connected with a counterweight ball, and the gravity of the counterweight ball is less than the elastic force of the torsion spring, an annular groove is provided on the outer side of the filter cover, the groove is located on the movement trajectory of the counterweight ball, and when the counterweight ball is in contact with the groove, the bristles on the cleaning rod just fit with the outer side of the filter cover.

[0014] Furthermore, an annular baffle is fixedly sleeved on a position of the rotating shaft near the front end, and the baffle is located between the cleaning rod and the fan blades.

[0015] Furthermore, a plurality of spherical bumps are evenly distributed in the groove, and the spherical bumps can contact the counterweight ball.

[0016] Technical effects and advantages of the present invention:

[0017] 1. The high-speed, low-noise centrifugal fan with air filtering effect of the present invention has made a new plan in terms of blade shape, blade structure, volute, volute tongue and the overall structure of the fan. In particular, a cyclone separator is added to the air inlet of the fan, so as to quickly separate and purify the high-speed gas entering the volute of the fan, and to settle and separate the dust and other garbage in the gas, thereby improving the air quality discharged into the atmosphere from the fan outlet and reducing the secondary pollution of sanitation operations;

[0018] 2. Significantly reduce the wear caused by dust erosion of the fan flow parts, extend the service life of the fan impeller and other flow parts, and reduce the dynamic unbalanced impact force caused by uneven wear of the fan impeller under high-speed rotation;

[0019] 3. Under the same working conditions, the noise level of the enhanced gear operation has been reduced from 86db to 78db, a decrease of 6db. Compared with the original fan, the space occupied by the high-speed and low-noise centrifugal fan has been reduced from 1.85m3 to 1.27m3, and the space requirement has been reduced by 31% compared with the original fan. Under the same working conditions such as a walking speed of 5km / h, the suction and pickup capacity during cleaning operations has been increased from 1000g / m2 to 1600g / m2. During the enhanced gear cleaning operation, any heavily polluted road surface can be cleaned once and for all to achieve a level of cleanliness that can be sat on the ground, which improves the use environment of the supporting bearings. In addition, during the enhanced gear operation, the power requirement of the fan has been reduced from 54.5kW to 49.4kW, and the efficiency has been increased by 9.4%.

[0020] 4. The present invention can use the filter cover to filter the air entering the fan during the operation of the fan, thereby cooperating with the cyclone separator's own partial separation of dust in the air to improve the cyclone separator's filtering effect on the air, and when the fan is in low-speed operation, the bristles on the cleaning rod can be used to clean the filter cover to ensure the filtering effect of the filter cover;

[0021] 5. The present invention is provided with a spherical protrusion. When the counterweight ball rolls along the groove, when the counterweight ball contacts the spherical protrusion, the counterweight ball can be lifted up by the spherical protrusion. Then, as the counterweight ball continues to roll, when the counterweight ball contacts the inner wall of the groove again under the action of the torsion spring, the vibration generated by the collision between the two can shake off the dust on the bristles, so that the dust can be quickly separated from the bristles. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a side cross-sectional view of all structures of the present invention except the filter assembly;

[0023] Figure 2 It is a structural schematic diagram of the fan impeller in the present invention;

[0024] Figure 3 The present invention Figure 2 A magnified view of part A;

[0025] Figure 4 is a cross-sectional view of a fan impeller in the present invention;

[0026] Figure 5 It is a schematic diagram of the structure of the fan blade in the present invention;

[0027] Figure 6 It is a three-dimensional schematic diagram of a cyclone separator and a filter assembly in the present invention;

[0028] Figure 7 The present invention Figure 6 A magnified view of part B;

[0029] Figure 8 It is a three-dimensional schematic diagram of the filter cover, the fixing ring, the counterweight ball and the fan blades in the present invention;

[0030] Fig. 9 It is a three-dimensional schematic diagram of the filter cover, the groove and the spherical protrusion in the present invention;

[0031] Fig.10 It is a three-dimensional schematic diagram of the separator outer cylinder, the separator inner cylinder, the separation inverted cone and the flange in the present invention.

[0032] In the figure: 1. fan volute; 2. fan impeller; 201. front disc; 202. middle disc; 203. fan blades; 3. drive motor; 4. air inlet pipe; 5. separator outer cylinder; 6. flange; 7. separator inner cylinder; 8. dust accumulation area; 9. separation inverted cone; 10. waist-shaped hole; 11. dust discharge pipe; 12. center guide hub; 13. guide spiral blades; 14. filter cover; 15. rotating shaft; 16. fan blades; 17. fixing ring; 18. cleaning rod; 19. bristles; 20. counterweight ball; 21. groove; 22. baffle; 23. spherical protrusion. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the embodiments of the present invention more clear, the technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments.

[0034] The present invention provides Figures 1 to 10A high-speed, low-noise centrifugal fan with air filtering effect shown in the figure comprises a fan volute 1, a fan impeller 2 is installed inside the fan volute 1, the fan impeller 2 comprises a front disc 201, a middle disc 202 and a plurality of fan blades 203, the plurality of fan blades 203 are located between the front disc 201 and the middle disc 202, the space between the front disc 201 and the middle disc 202 and two adjacent fan blades 203 constitutes a flow channel of the fan impeller 2, a drive motor 3 is installed on the rear side of the fan volute 1, and the output shaft of the drive motor 3 rotates through the plug At the center of the circle on the rear side of the fan volute 1, the output end of the drive motor 3 is connected to the fan impeller 2 in a transmission manner. An air inlet is arranged on the front side of the fan volute 1. An air inlet pipe 4 is plugged into the air inlet. A cyclone separator is connected to the front end of the air inlet pipe 4. The cyclone separator includes a separator outer cylinder 5. A flange 6 is fixedly connected to the rear end of the separator outer cylinder 5. The flange 6 is fixedly connected to the front end of the air inlet pipe 4 by bolts. A coaxial separator inner cylinder 7 is arranged on the inner side of the separator outer cylinder 5. The separator inner cylinder 7 has a The wall of the front half of the cylinder is inclined toward the direction close to the separator outer cylinder 5, and the separator inner cylinder 7 is fixedly connected to the front end of the separator outer cylinder 5, the rear end of the separator inner cylinder 7 is fixedly connected to the flange 6, and the gap between the separator outer cylinder 5 and the separator inner cylinder 7 forms a dust gathering area 8, and an annular separation inverted cone 9 is fixedly connected to the inner wall of the rear end of the separator inner cylinder 7, and the diameter of the separation inverted cone 9 gradually increases from front to back, and a plurality of waist-shaped holes 10 are distributed in an annular manner on the separator inner cylinder 7, and the waist-shaped holes 10 are located at the separation inverted cone 9. Relative to the area, a dust discharge pipe 11 is connected to the bottom of the separator outer cylinder 5, a central guide hub 12 is arranged at the axial center of the front end of the separator inner cylinder 7, and a guide spiral blade 13 is fixedly connected to the central guide hub 12. The guide spiral blade 13 is fixedly connected to the inner wall of the separator inner cylinder 7 on the side away from the central guide hub 12. There are three guide spiral blades 13, and the three guide spiral blades 13 are evenly distributed in the separator inner cylinder 7. The guide spiral blades 13 and the central guide hub 12 are connected together by welding.

[0035] like Figures 2 to 5 As shown, the fan impeller 2 can be manufactured by welding or casting, the fan blade 203 adopts a backward design, the outlet angle α of the fan blade 203 is 28.6°, the inlet angle β of the fan blade 203 is 14.5°, the length of the fan blade 203 is L, and L=kx(R2-R1), wherein R1 is the inner diameter of the fan blade 203, R2 is the outer diameter of the fan blade 203, k is the empirical coefficient, and k is greater than 2.5;

[0036] The present invention reduces the inlet impact angle of the fan blade 203, thereby ensuring the efficiency of the fan. By setting the coefficient k to be greater than 2.5, the traditional practice of taking the coefficient k as about 1.5 is broken, so that the fan blade 203 is relatively long, so that the fan blade 203 has sufficient ability to work on the gas, and the energy of the gas, including kinetic energy and static pressure, is increased in a certain proportional relationship, which effectively solves the shortcoming that the energy provided by the backward fan blade 203 is not high enough.

[0037] like Figures 2 to 5 As shown, the pressure-bearing surface and the non-pressure-bearing surface of the fan blade 203 are both formed by multi-segment curve fitting, and the fan blade 203 is a through-hole structure;

[0038] By designing the fan blade 203 as a hollow structure, the weight of the fan impeller 2 can be significantly reduced, thereby reducing the overall centrifugal force of the fan impeller 2, while also reducing the inlet impact and improving the efficiency of the fan. The design of the multi-segment curved pressure-bearing surface a1 and non-pressure-bearing surface a2 of the fan blade 203 ensures that no secondary flow is generated in the flow channel. In addition, the through channel of the fan blade 203 can also balance the unbalanced pressure on the outside of the front disk 201 and the middle disk 202 of the fan impeller 2, thereby reducing the vibration of the fan impeller 2 during rotation.

[0039] like Figure 1 As shown, the air inlet pipe 4 is connected to the air inlet at the front end of the fan impeller 2 by means of a sleeve-jointed overlapping manner, the single-sided gap between the two is 0.3 mm, and the length of the sleeve-jointed overlapping portion reaches 5% of the inlet diameter of the fan impeller 2, which makes the connection between the air inlet pipe 4 and the front end of the fan impeller 2 almost form a return flow channel, thereby solving the problem of the existing fan forming a serious vortex zone here, disrupting the smoothness of the air intake and reducing the volumetric efficiency of the fan operation.

[0040] like Figure 3 As shown, the volute tongue of the fan volute 1 adopts a multi-segment combination type, and the specific combination form is: a combined volute tongue of a logarithmic spiral segment χ1+a tangent straight line segment χ2+an Archimedean spiral segment χ3;

[0041] Firstly, the reflection function of the logarithmic spiral is used to allow the airflow that hits the volute tongue to return as much as possible and merge into the main airflow. The straight line segment plays a role of slow transition. Even if the airflow is rolled back into the volute tongue with the fan impeller 2, it will not immediately diffuse to form a boundary layer, which is beneficial to reduce the eddy loss near the volute tongue. The outer circle gap Δ2 between the volute tongue and the fan impeller 2 is only 5% larger than the general volute tongue y gap Δ1. However, this alone can reduce the noise by 4db and increase the efficiency by 3%.

[0042] like Figures 6 to 9As shown, a filter assembly is provided at the front end of the separation inverted cone 9, and the filter assembly includes a filter cover 14, the filter cover 14 is detachably mounted on the front end of the separation inverted cone 9, and the rear end opening of the filter cover 14 is sleeved on the outside of the separation inverted cone 9, the front end of the filter cover 14 is vertically rotated and inserted with a rotating shaft 15, and a plurality of fan blades 16 are annularly distributed on the front end surface of the rotating shaft 15, and a fixing ring 17 is rotatably sleeved near the rear end of the rotating shaft 15, and a plurality of fixing rods are fixedly connected between the side of the fixing ring 17 and the inner side of the filter cover 14, and a plurality of cleaning rods 1 are annularly distributed on the outer side of the filter cover 14. 8. The cleaning rod 18 is close to the outer side of the filter cover 14, and the side of the cleaning rod 18 opposite to the surface of the filter cover 14 is evenly provided with bristles 19. The end of the cleaning rod 18 close to the rotating shaft 15 is hinged to the rotating shaft 15 through a torsion spring. The free end of the cleaning rod 18 is rotatably connected with a weight ball 20, and the gravity of the weight ball 20 is less than the elastic force of the torsion spring. The outer side of the filter cover 14 is provided with an annular groove 21, and the groove 21 is located on the movement trajectory of the weight ball 20. When the weight ball 20 fits with the groove 21, the bristles 19 on the cleaning rod 18 just fit with the outer side of the filter cover 14.

[0043] By providing the filter cover 14, when the external airflow enters the cyclone separator, the filter cover 14 can filter the incoming air, thereby cooperating with the cyclone separator's own partial separation of dust in the air, thereby improving the cyclone separator's filtering effect on the air;

[0044] When the fan is in low gear operation, as the airflow blows on the fan blades 16, the fan blades 16 can drive the rotating shaft 15 to rotate under the action of the airflow, and as the rotating shaft 15 rotates, the plurality of cleaning rods 18 can drive the weighted balls 20 to roll along the grooves 21 under the action of the torsion springs, and at this time, the bristles 19 on the cleaning rods 18 can brush against the outer side of the filter cover 14, thereby cleaning the filter cover 14 and ensuring the filtering effect of the filter cover 14, and the dust brushed off by the bristles 19 can fall along the outer side of the filter cover 14 into the area where the waist-shaped holes 10 are located, and finally discharged through the dust discharge pipe 11;

[0045] When the fan is in high-end operation, the speed at which the airflow enters the separator inner tube 7 also increases. At this time, the speed at which the fan blades 16 drive the rotating shaft 15 to rotate also increases. As the rotating shaft 15 rotates rapidly, the centrifugal force exerted on the counterweight ball 20 gradually increases. Subsequently, the counterweight ball 20 can pull the cleaning and cleaning cover surface apart under the action of centrifugal force. At this time, the bristles 19 on the cleaning rod 18 no longer clean the filter cover 14, thereby avoiding the dust brushed by the bristles 19 from being sucked into the fan volute 1 through the filter cover 14 due to excessive suction when the fan is in high-end working condition.

[0046] like Figure 7 As shown, the rotating shaft 15 is fixedly sleeved with an annular baffle 22 near the front end, and the baffle 22 is located between the cleaning rod 18 and the fan blade 16;

[0047] By providing the baffle 22 , when the cleaning rod 18 deflects toward the direction close to the fan blade 16 under the action of the centrifugal force of the counterweight ball 20 , the baffle 22 can limit the deflection angle of the cleaning rod 18 , thereby avoiding the cleaning rod 18 from colliding with the fan blade 16 .

[0048] like Fig. 9 As shown, a plurality of spherical bumps 23 are evenly distributed in the groove 21, and the spherical bumps 23 can contact with the weight ball 20;

[0049] By providing a spherical protrusion 23, during the process of the counterweight ball 20 rolling along the groove 21, when the counterweight ball 20 contacts the spherical protrusion 23, the counterweight ball 20 can be lifted up by the spherical protrusion 23, and then as the counterweight ball 20 continues to roll, when the counterweight ball 20 contacts the inner wall of the groove 21 again under the action of the torsion spring, the vibration generated by the collision between the two can shake off the dust on the bristles 19, so that the dust can be quickly separated from the bristles 19, and then the shaken-off dust can enter the area where the waist-shaped hole 10 is located along the outer side of the air guide cover, and finally be discharged through the dust exhaust pipe 11.

[0050] Working principle: Under the attraction of the fan, the gas flows from the inlet of the cyclone separator around the central guide hub 12, along the spiral guide blades and into the separator through the V1 flow channel;

[0051] Then it rotates in the spiral flow channel formed by the central guide hub 12, the spiral guide blades, and the separator inner tube 7 and moves forward axially at high speed;

[0052] Due to the centrifugal force of the high-speed rotating airflow, dust and other particles circle along the streamline V3 close to the separator inner cylinder 7, and constantly collide and rub against the wall, losing the energy of high-speed forward movement and significantly reducing the flow speed. After hitting the separation inverted cone 9, they are blocked and fall into the dust accumulation area 8 through several waist-shaped holes 10 on the separator inner cylinder 7. Finally, the streamline V4 flows out of the separator through the dust discharge port.

[0053] The gas purified in the cyclone separator enters the fan along the flow channel V2, then turns approximately and enters the circumferentially arranged blade paths on the impeller along the flow channel V5 perpendicular to the axial direction;

[0054] When the gas passes through the blades of the rotating impeller, its speed is increased, and it gains energy from the blades, increasing both the static pressure and kinetic energy.

[0055] As the gas gains more energy from the impeller passage, the gas is thrown out from the impeller flow passage outlet by the impeller and enters the volute. The volute space is relatively large, the gas speed entering the volute decreases, and the static pressure increases;

[0056] In the volute, the gas is divided into three directions: one is to flow to the outside of the front disk 201 and the rear disk of the impeller. At the same time, the gas on the outside of the front disk 201 and the rear disk can also be pressure-equalized through the through-channel of the wing blades; the other is to converge along the flow channel V6 and flow to the outlet of the volute to further realize the conversion of gas dynamic and static pressure, so that the static pressure continues to increase, and part of the dynamic pressure is recovered, and finally flows out of the outlet of the fan volute 1 through the flow channel V8; in addition, a small amount of flow follows the rotating impeller, passes through the volute tongue along the flow channel V7, and is drawn into the volute to enter the next cycle.

[0057] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them.

Claims

1. A high-speed, low-noise centrifugal fan with air filtering effect, comprising a fan volute (1), characterized in that: A fan impeller (2) is installed inside the fan volute (1), the fan impeller (2) comprising a front disc (201), a middle disc (202) and a plurality of fan blades (203), the plurality of fan blades (203) being located between the front disc (201) and the middle disc (202), the space between the front disc (201) and the middle disc (202) and between two adjacent fan blades (203) forming a flow passage of the fan impeller (2), a drive motor (3) being installed at the rear side of the fan volute (1), the output shaft of the drive motor (3) being rotatably inserted into the The fan volute (1) is at the center of a circle on the rear side, and the output end of the drive motor (3) is drivingly connected to the fan impeller (2); the front side of the fan volute (1) is provided with an air inlet, an air inlet pipe (4) is plugged into the air inlet, a cyclone separator is connected to the front end of the air inlet pipe (4), the cyclone separator comprises a separator outer cylinder (5), a flange (6) is fixedly connected to the rear end of the separator outer cylinder (5), the flange (6) and the front end of the air inlet pipe (4) are fixedly connected together by bolts, and the inner side of the separator outer cylinder (5) is provided with a A coaxial separator inner cylinder (7) is arranged, the front half of the cylinder wall of the separator inner cylinder (7) is inclined in a direction close to the separator outer cylinder (5), and the separator inner cylinder (7) is fixedly connected to the front end of the separator outer cylinder (5), the rear end of the separator inner cylinder (7) is fixedly connected to the flange (6), and the gap between the separator outer cylinder (5) and the separator inner cylinder (7) forms a dust accumulation area (8), and an annular separation inverted cone (9) is fixedly connected to the inner wall of the rear end of the separator inner cylinder (7), and the diameter of the separation inverted cone (9) is The separator inner cylinder (7) is gradually enlarged from front to back, a plurality of waist-shaped holes (10) are annularly distributed on the separator inner cylinder (7), and the waist-shaped holes (10) are opposite to the area where the separation inverted cone (9) is located, the bottom of the separator outer cylinder (5) is connected to a dust discharge pipe (11), a central flow guide hub (12) is arranged at the axial center of the front end of the separator inner cylinder (7), and a flow guide spiral blade (13) is fixedly connected to the central flow guide hub (12) around the body, and the side of the flow guide spiral blade (13) away from the central flow guide hub (12) is fixedly connected to the inner wall of the separator inner cylinder (7); The fan impeller (2) can be manufactured by welding or casting, the fan blade (203) adopts a backward design, the fan blade (203) has an outlet angle of 28.6°, the fan blade (203) has an inlet angle of 14.5°, the fan blade (203) has a length of L, and L=kx(R2-R1), wherein R1 is the inner diameter of the fan blade (203), R2 is the outer diameter of the fan blade (203), k is an empirical coefficient, and k is greater than 2.5; The volute tongue portion of the fan volute (1) adopts a multi-segment combination type, and the specific combination form is: a combined volute tongue of a logarithmic spiral segment + a tangent straight line segment + an Archimedean spiral segment; A filter assembly is provided at the front end of the separation inverted cone (9), and the filter assembly comprises a filter cover (14). The filter cover (14) is detachably mounted on the front end of the separation inverted cone (9), and the rear end opening of the filter cover (14) is sleeved on the outside of the separation inverted cone (9). A rotating shaft (15) is inserted and penetrated through the front end of the filter cover (14) for vertical rotation. A plurality of fan blades (16) are annularly distributed on the front end surface of the rotating shaft (15). A fixing ring (17) is rotatably sleeved at a position close to the rear end of the rotating shaft (15). A plurality of fixing rods are fixedly connected between the side surface of the fixing ring (17) and the inner side of the filter cover (14). A plurality of cleaning rods (18) are annularly distributed on the outer side of the filter cover (14). The cleaning rod (18) is close to the outer side of the filter cover (14), and bristles (19) are evenly arranged on the side of the cleaning rod (18) opposite to the surface of the filter cover (14). The end of the cleaning rod (18) close to the rotating shaft (15) is hinged to the rotating shaft (15) through a torsion spring. The free end of the cleaning rod (18) is rotatably connected to a counterweight ball (20), and the gravity of the counterweight ball (20) is smaller than the elastic force of the torsion spring. An annular groove (21) is arranged on the outer side of the filter cover (14). The groove (21) is located on the movement trajectory of the counterweight ball (20), and when the counterweight ball (20) is in contact with the groove (21), the bristles (19) on the cleaning rod (18) just fit into the outer side of the filter cover (14); A plurality of spherical bumps (23) are evenly distributed in the groove (21), and the spherical bumps (23) are capable of contacting the weighted ball (20).

2. A high-speed, low-noise centrifugal fan with air filtering effect according to claim 1, characterized in that: The pressure-bearing surface and the non-pressure-bearing surface of the fan blade (203) are both formed by multi-segment curve fitting, and the fan blade (203) is a through-hole structure.

3. A high-speed, low-noise centrifugal fan with air filtering effect according to claim 2, characterized in that: The air inlet pipe (4) is connected to the air inlet at the front end of the fan impeller (2) by means of a sleeve-jointed overlapping manner, the single-side gap between the two is 0.3 mm, and the length of the sleeve-jointed overlapping portion reaches 5 percent of the inlet diameter of the fan impeller (2).

4. A high-speed, low-noise centrifugal fan with air filtering effect according to claim 3, characterized in that: There are three flow-guiding spiral blades (13), and the three flow-guiding spiral blades (13) are evenly distributed in the separator inner tube (7), and the flow-guiding spiral blades (13) and the central flow-guiding hub (12) are connected together by welding.

5. A high-speed, low-noise centrifugal fan with air filtering effect according to claim 4, characterized in that: An annular baffle (22) is fixedly sleeved on a position close to the front end of the rotating shaft (15), and the baffle (22) is located between the cleaning rod (18) and the fan blade (16).

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