CN215890511U - Centrifugal fan - Google Patents

Abstract

The utility model discloses a centrifugal fan, which comprises a volute, an impeller and an annular fixing strip, wherein the annular fixing strip is arranged around the impeller and fixedly connected with the outer edge of the end part of one end of a blade close to an air inlet; and a plurality of leakage-proof blades which are arranged at intervals are fixed on one surface of the annular fixing strip, which is close to the air inlet. According to the utility model, the impeller and volute structures of the centrifugal fan are improved, the annular fixing strip is additionally arranged on the outer edge of the impeller, the leakproof blade is arranged on one surface of the annular fixing strip close to the air inlet, and the working capacity of the top area of the impeller is enhanced by utilizing the leakproof blade, so that the working uniformity of the whole impeller is improved; meanwhile, the gap between the impeller and the volute is filled through the leakage-proof blades, the work capacity of the impeller is enhanced, the trend of backflow of regional airflow between the impeller and the volute air inlet is hindered, and finally the leakage loss of air at the volute air inlet is reduced.

Description

Centrifugal fan

Technical Field

The utility model relates to the technical field of fan equipment, in particular to a centrifugal fan.

Background

The centrifugal fan can accelerate gas by utilizing an impeller rotating at a high speed according to the principle that kinetic energy is converted into potential energy, then decelerates and changes the flow direction, so that the kinetic energy is converted into the potential energy, the gas pressure can be improved, and the gas can be discharged. Because the impeller of the centrifugal fan has the problems of jumping along the rotating shaft and shaking along the radial direction when rotating, a sufficient gap must be reserved between the impeller of the centrifugal fan and the inner wall of the volute so as to prevent the centrifugal fan from scraping and colliding with the volute in the work process.

The working pressure difference of the centrifugal fan is large, particularly between the air inlet and the air outlet of the centrifugal fan, and the air pressure leakage problem of the centrifugal fan during working is serious due to the existence of the gap between the impeller of the centrifugal fan and the volute, so that the air quantity can be reduced, the working efficiency of the centrifugal fan is influenced, and great working noise can be generated.

Leakage losses are typically reduced in the prior art by reducing the fit clearance between the impeller and the volute, providing a feature in the axial direction of the impeller shaft to impede air flow. For example, the patent application with publication number CN 110594197a discloses a centrifugal fan and a range hood, the centrifugal fan includes a flow limiting member installed inside a volute, the flow limiting member corresponds to an end face of an impeller and is arranged in a gap with the end face of the impeller, and a backflow phenomenon between the volute and the end face of the impeller can be improved. The utility model patent application with the publication number of CN 104295531A discloses a centrifugal fan and an air conditioner, and solves the technical problems of large leakage loss and low efficiency of the centrifugal fan in the prior art; the edge of the volute inlet of the centrifugal fan forms a volute air inlet guide ring body, a leakage flow blocking body is arranged on a leakage gas flow channel from the outlet to the inlet in the volute, and the leakage flow blocking body is fixedly arranged on the impeller and/or the volute.

Although the above-mentioned prior art's scheme is all through setting up different structural feature, can increase the difficult degree of air backflow process to a certain extent to reduce the volume of letting out, this kind of technical scheme still can not restrain the air current flow of gap department between impeller and the spiral case, and is still not ideal to the improvement effect of leaking the loss, and the effect is limited. Secondly, because the volute diversion port is arranged, air entering the volute structure of the centrifugal fan is subjected to the diversion and blocking effects of the diversion port, and the acting capacity of the blade area close to the top of the centrifugal fan is low, so that the tendency of airflow backflow from the top of the centrifugal fan and the seam of the volute is increased.

SUMMERY OF THE UTILITY MODEL

The technical problem to be solved by the utility model is as follows: the centrifugal fan can reduce air leakage loss at the air inlet.

In order to solve the technical problems, the utility model adopts the technical scheme that: the centrifugal fan comprises a volute and an impeller, wherein the impeller consists of a wheel disc which is rotatably arranged in the volute and a plurality of blades which are annularly arranged around the wheel disc, the volute is provided with an air inlet and an air outlet which are communicated with the interior of the volute, the air inlet is a circular opening arranged on the side of the impeller, the rotating axis of the impeller and the circle center of the air inlet are positioned on the same straight line, the centrifugal fan also comprises an annular fixing strip, the annular fixing strip is arranged around the impeller and fixedly connected with the outer edge of the end part of one end, close to the air inlet, of the blade, and the root part of the inner edge of the blade is fixedly connected with the wheel disc; and a plurality of leakage-proof blades which are arranged at intervals are fixed on one surface of the annular fixing strip, which is close to the air inlet.

Further, the method comprises the following steps: the leakage-proof blades are uniformly arranged on the annular fixing strip in an annular mode, and the number of the leakage-proof blades is larger than that of the blades.

Further, the method comprises the following steps: the number of the leakage-proof blades is 2-3 times of the number of the blades.

Further, the method comprises the following steps: the height of the leakage-proof blade is 2-10 mm.

Further, the method comprises the following steps: the height of the leakproof leaves is 5 mm.

Further, the method comprises the following steps: the horizontal distance from the inner edge of the leakage-proof blade to the center of the impeller is greater than or equal to the horizontal distance from the inner edge of the blade to the center of the impeller.

Further, the method comprises the following steps: the leakage-proof blades are arc-shaped plates which are obliquely fixed on the annular fixing strip.

Further, the method comprises the following steps: one surface of the annular fixing strip, which is close to the air inlet, is an inclined curved surface, the curved surface inclines from the outer edge direction of the annular fixing strip to the inner edge direction of the annular fixing strip, and the height of the outer edge of the annular fixing strip is greater than that of the inner edge of the annular fixing strip; the side of the annular fixing strip far away from the air inlet is a plane.

The utility model has the beneficial effects that: according to the utility model, the impeller and volute structures of the centrifugal fan are improved, the annular fixing strip is additionally arranged on the outer edge of the impeller, the leakproof blade is arranged on one surface of the annular fixing strip close to the air inlet, and the working capacity of the top area of the impeller is enhanced by utilizing the leakproof blade, so that the working uniformity of the whole impeller is improved; meanwhile, the gap between the impeller and the volute is filled through the leakage-proof blades, and the air outlet channel of the leakage-proof blades is reduced by utilizing the inclined curved surface of the annular fixing strip, so that the jet kinetic energy of the air flow is improved, the acting capacity of the impeller is enhanced, the trend of backflow of the air flow in the area between the impeller and the volute air inlet is hindered, and finally the leakage loss of the air at the volute air inlet is reduced.

Drawings

FIG. 1 is an isometric view of the present invention;

FIG. 2 is an isometric view of the impeller;

FIG. 3 is an enlarged cross-sectional view taken at A in FIG. 2;

labeled as: 100-volute, 200-impeller, 210-wheel disc, 220-blade, 300-air inlet, 400-air outlet, 500-annular fixed strip, 510-curved surface and 600-leakproof blade.

Detailed Description

In order to facilitate understanding of the utility model, the utility model is further described below with reference to the accompanying drawings.

As shown in fig. 1 to 3, the centrifugal fan disclosed in the present invention is composed of a volute 100 and an impeller 200, wherein the impeller 200 is composed of a disk 210 and blades 220, the disk 210 is rotatably installed inside the volute 100 by a rotating shaft, and a plurality of blades 220 are annularly disposed around the outer circumference of the disk 210 and fixed on the disk 210; the volute 100 is of a hollow structure, an air inlet 300 and an air outlet 400 which are communicated with the interior of the volute 100 are arranged on the volute 100, the air inlet 300 is a circular opening arranged on the side of the impeller 200, and the rotation axis of the impeller 200 and the circle center of the air inlet 300 are positioned on the same straight line.

In order to reduce the air leakage loss at the air inlet 400 of the volute 100, a ring of annular fixing strips 500 are added on the impeller 200, and a plurality of leakage-proof blades 600 are arranged on the annular fixing strips 500. As shown in fig. 1 and 2, the annular fixing strip 500 is a ring-shaped strip structure, the annular fixing strip 500 is disposed around the impeller 200, the annular fixing strip 500 is fixedly connected to an end portion of the vane 220 close to the air inlet 300 of the volute 100, an inner diameter of the annular fixing strip 500 is equal to an outer diameter of the impeller 200, the annular fixing strip 500 is fixedly connected to an outer edge of each vane 220, and a root portion of the inner edge of the vane 220 is fixedly connected to the wheel disc 210, so that the annular fixing strip 500 forms a convex edge structure at an end of the impeller 200 close to the air inlet 300. According to the utility model, under the condition that the gap between the volute 100 of the centrifugal fan and the impeller 200 is ensured to be small enough and the height of the blades 220 is not reduced, the distance between the outlet and the inlet of the impeller 200 is increased by arranging the annular fixing strip 500, the backflow resistance from the outlet to the inlet of the impeller 200 can be increased, and the purpose of reducing the air pressure leakage loss of the gap between the impeller 200 of the centrifugal fan and the volute 100 is achieved. Meanwhile, as the leak-proof blades 600 are arranged on the annular fixing strip 500, when airflow is sucked into the centrifugal fan from the air inlet 300 of the volute 100, the work-doing capability of the impeller 200 close to the air inlet 300 can be enhanced by the leak-proof blades 600, the work-doing uniformity of the whole impeller 200 is effectively improved, and the clearance between the impeller 200 and the volute 100 is reduced due to the increase of the leak-proof blades 600, so that the trend of airflow backflow in the area can be effectively hindered while the work-doing capability of the impeller 200 is enhanced.

As shown in fig. 2, the anti-leakage blades 600 provided in the present invention are uniformly arranged in a ring shape on one surface of the ring-shaped fixing strip 500 close to the air inlet 300, and a gap for allowing an air flow to pass is left between adjacent anti-leakage blades 600. In order to improve the working efficiency, the working efficiency of the leakage-proof blade 600 area is higher than that of the blade 220 area, and the number of the leakage-proof blades 600 is larger than that of the blades 220; according to the test, it is preferable that the number of the leakage preventing blades 600 is 2 to 3 times the number of the blades 220, the height of the leakage preventing blades 600 is generally set to 2 to 10mm, and the height of the leakage preventing blades 600 is preferably 5 mm. The circle center of the circle surrounded by the leakage-proof blades 600 is positioned on the rotating axis of the impeller 200, so that the leakage-proof blades 600 and the blades 220 rotate coaxially, and the uniformity of work application is ensured; the horizontal distance from the inner edge of the leakage-proof vane 600 to the center of the impeller 200 is greater than or equal to the horizontal distance from the inner edge of the vane 220 to the center of the impeller 200, i.e. the inner diameter of the leakage-proof vane 600 is not less than the outer diameter of the vane 220. As the blades 220 are generally inclined arc-shaped plates, the anti-leakage blades 600 also adopt arc-shaped plates, the anti-leakage blades 600 are obliquely fixed on the annular fixing strip 500, the inclination angle of the anti-leakage blades 600 is consistent with that of the blades 220, the bending direction of the anti-leakage blades 600 is consistent with that of the blades 220, and the uniformity of doing work is ensured.

In order to further reduce the air leakage loss, the structure of the annular fixing strip 500 is further defined in the present invention, as shown in fig. 2 and 3, a side of the annular fixing strip 500 close to the intake vent 300 is provided with an inclined slope 510, and a side of the annular fixing strip 500 far from the intake vent 300 is a flat surface. The curved surface 510 inclines from the outer edge direction of the annular fixing strip 500 to the inner edge direction of the annular fixing strip 500, and the height of the outer edge of the annular fixing strip 500 is greater than the height of the inner edge of the annular fixing strip 500, so that the annular fixing strip 500 forms a structure with high outside and low inside, an air outlet channel of the leakage-proof blade 600 is reduced, and the jet kinetic energy of the air outlet flow of the leakage-proof blade 600 is improved; through improving the structure of the annular fixing strip 500, the airflow sucked into the volute 100 from the air inlet 300 has a tendency of moving upwards under the action of the leakage-proof blades 600, the airflow entering the volute 100 is extruded, the pressure of the airflow blown out by the impeller 200 is enhanced, the airflow moving upwards is close to the inside of the volute 100 to form an air resistance, and the backflow effect at the gap between the impeller 200 and the volute 100 can be effectively prevented.

Examples

The impeller height of centrifugal fan is 80mm, and the blade quantity is 41, and the blade diameter of impeller is 160mm, and the thickness of annular fixed top is 2mm, and the blade height of impeller is 73mm, and the height of leak protection blade is 5mm, and the quantity of leak protection blade is 120. The centrifugal fan who compares above-mentioned centrifugal fan and conventional structure, under the same, the unanimous prerequisite of blade shape of impeller size, centrifugal fan's amount of wind promotes 4% in this embodiment, and air-out efficiency promotes 2%.

Claims (8)

1. Centrifugal fan, including spiral case (100) and impeller (200), impeller (200) comprise rotary set rim plate (210) in spiral case (100) and a plurality of blade (220) that set up around rim plate (210) annular, be equipped with air intake (300) and air outlet (400) with spiral case (100) inside intercommunication on spiral case (100), air intake (300) are the circular mouth that sets up in impeller (200) side, and the rotation axle center of impeller (200) and the centre of a circle of air intake (300) are located same straight line, its characterized in that: the impeller structure is characterized by further comprising an annular fixing strip (500), wherein the annular fixing strip (500) is arranged around the impeller (200) and fixedly connected with the outer edge of the end part of one end, close to the air inlet (300), of each blade (220), and the root part of the inner edge of each blade (220) is fixedly connected with the wheel disc (210); and a plurality of leakage-proof blades (600) which are arranged at intervals are fixed on one surface of the annular fixing strip (500) close to the air inlet (300).

2. The centrifugal fan of claim 1, wherein: the leakage-proof blades (600) are uniformly arranged on the annular fixing strip (500) in an annular shape, and the number of the leakage-proof blades (600) is greater than that of the blades (220).

3. The centrifugal fan of claim 2, wherein: the number of the leakage-proof blades (600) is 2-3 times of the number of the blades (220).

4. The centrifugal fan of claim 1, wherein: the height of the leakage-proof blade (600) is 2-10 mm.

5. The centrifugal fan of claim 4, wherein: the height of the leakage-proof blade (600) is 5 mm.

6. The centrifugal fan of claim 1, wherein: the horizontal distance from the inner edge of the leakproof blade (600) to the circle center of the impeller (200) is greater than or equal to the horizontal distance from the inner edge of the blade (220) to the circle center of the impeller (200).

7. The centrifugal fan of claim 1, wherein: the leakage-proof blades (600) are arc-shaped plates which are obliquely fixed on the annular fixing strip (500).

8. The centrifugal fan of claim 1, wherein: one surface, close to the air inlet (300), of the annular fixing strip (500) is an inclined curved surface (510), the curved surface (510) inclines from the outer edge direction of the annular fixing strip (500) to the inner edge direction of the annular fixing strip (500), and the height of the outer edge of the annular fixing strip (500) is greater than that of the inner edge of the annular fixing strip (500); one side of the annular fixing strip (500) far away from the air inlet (300) is a plane.

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