A structure for simultaneously increasing air volume of centrifugal forward and reverse rotation fan blades

Abstract

The application relates to a structure for simultaneously improving air volume of centrifugal forward and reverse fan blades, belonging to the fan technical field, and comprising a fan body, wherein the fan body comprises a rotating shaft and a plurality of fan blades connected with the rotating shaft, any of the fan blades comprises an inner end and an outer end, the inner end comprises a connecting section and an extending section, the connecting section is formed by a connecting line between the fan blade and the rotating shaft, the extending section is formed by a curve above the connecting line, and the outer end is formed by a side edge contour of the fan blade away from the rotating shaft; the shapes of the inner end and the outer end are both curves, the bending directions of the connecting section and the outer end are opposite, and the bending direction of the outer end faces the rotating direction of the fan blade during forward rotation; the structure has the characteristics of simultaneously improving the air volume of forward and reverse rotation compared with the scheme that the bending directions of the inner end and the outer end are consistent and the bending degrees of the inner end and the outer end are consistent.

Description

Technical Field

[0001] This invention belongs to the field of fan technology, specifically relating to a structure that simultaneously increases the airflow of centrifugal fan blades in both forward and reverse rotation. Background Technology

[0002] A fan is a widely used device in both production and daily life. It mainly uses a motor to drive the fan blades to rotate and generate air pressure, thereby achieving the purpose of heat dissipation or promoting airflow.

[0003] Since the fan blades are the core component generating air pressure, and fan noise is mainly manifested as fluid noise, the shape of the fan blades directly determines the air pressure, and thus the heat dissipation effect, airflow effect, and noise level. Typical fan structures, such as the fan blade assembly disclosed in Chinese Patent CN120212084A, do not undergo any noise reduction treatment and are quite noisy. As people's demands for quiet fans increase, some existing fans have raised flanges at the ends of the fan blades. However, while this solution is effective, it sacrifices the fan's heat dissipation performance and cannot meet the customer's system heat dissipation needs. Therefore, Chinese Patent CN219139460U discloses a novel noise reduction method. The fan structure includes fan blades within a fan frame. The outer diameter of the fan blade hub features spirally curved blades with equidistantly distributed arc-shaped bevels. The inner diameter of the outlet end of the fan frame has equidistantly curved outlet vanes. The angle between the outlet vanes at the connection point of the fan frame is α, greater than 40 degrees and less than 70 degrees. The ends of the fan blades have reverse-curved side wings, and the forward sweep angle at the ends of the fan blades is β, greater than 20 degrees and less than 50 degrees. The sum of α and β is greater than 70 degrees and less than 100 degrees. The inner diameter of the inlet end of the fan frame has an inlet guide radius. The forward sweep angle of the aforementioned fan blades is irregular, thereby effectively reducing fan stall, turbulence, and noise.

[0004] In the above solution, the outer end of the fan blade is irregularly treated to make the angle of the outer edge of the blade different from that of other parts of the fan blade, thereby achieving the effect of reducing noise. However, during the fan's reverse rotation, some airflow is drawn in by the inner end of the blade and thrown outwards from the center of the fan blade under the drive of centrifugal force, which affects the final air volume. Although the above solution treats the outer end to ensure the air volume in the forward rotation state, it does not treat the shape of the inner end and cannot overcome the aforementioned problems. Therefore, a structure that can simultaneously improve the centrifugal forward and reverse rotation fan blade air volume is needed. Summary of the Invention

[0005] To address the aforementioned problems in the prior art, this invention provides a structure that simultaneously increases the air volume of both forward and reverse centrifugal fan blades, featuring the ability to simultaneously increase the air volume output in both forward and reverse rotation.

[0006] The objective of this invention can be achieved through the following technical solutions: A structure that simultaneously improves the airflow of centrifugal forward and reverse fan blades includes a fan body, the fan body including a rotating shaft and a plurality of fan blades connected to the rotating shaft, each of the fan blades including an inner end and an outer end, the inner end including a connecting section and an extension section, the connecting section being formed by a connecting line between the fan blade itself and the rotating shaft, the extension section being formed by a curve located above the connecting line, and the outer end being formed by the edge contour of the fan blade away from the rotating shaft. Both the inner and outer ends are curved, and the connecting section and the outer end bend in opposite directions, with the outer end bending in the direction of the fan blades' rotation when rotating forward.

[0007] As a preferred embodiment of the present invention, the inner curvature of the inner end curve is 30~35.

[0008] As a preferred embodiment of the present invention, the fan blade further includes an upper end and a lower end, both of which are curved and are parallel to the air outlet surface.

[0009] As a preferred embodiment of the present invention, the fan blade includes an inner section and an outer section connected to each other. The inner section and the outer section are two arc-shaped plate structures with opposite concave directions, which are integrally formed. The inner section is closer to the pivot than the outer section, and the inner section and the outer section have a smooth transition.

[0010] As a preferred embodiment of the present invention, the outer radius of any of the fan blades is 65~75mm and the inner radius is 16~20mm.

[0011] As a preferred embodiment of the present invention, the forward sweep angle of any of the fan blades is 37~43°.

[0012] The beneficial effects of this invention are as follows: (1) By setting the bending direction of the connecting section of the inner end formed by the connecting line of the fan blade close to the shaft to the opposite bending direction of the edge of the fan blade away from the shaft, compared with the scheme where the inner and outer ends have the same bending direction, the effect of the innermost side of the fan blade to draw out the air is weakened, reducing the weakening effect on the air outlet, thereby increasing the air outlet volume when rotating in reverse. At the same time, since there is a concave curved surface at the inner end of the fan blade in the direction of rotation when rotating in the forward direction, the air intake volume at the inner end is increased when rotating in the forward direction, thereby increasing the air outlet volume when rotating in the forward direction. (2) By setting the inner curvature of the inner end connecting section to 30~35, compared with the scheme where the inner and outer ends have the same curvature direction, a greater improvement effect on the air volume in both forward and reverse rotation is achieved, further ensuring the air volume in both forward and reverse rotation. (3) By setting the outer radius of the fan blade to 65~75mm and the inner radius to 16~20mm, the reverse air volume is reduced due to the large radius. At the same time, the structural instability caused by the excessive weight of the fan blade is reduced, and the air volume is further avoided due to the small size of the fan blade. Attached Figure Description

[0013] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0014] Figure 1 This is a schematic diagram of the bending direction of the fan blades in the prior art; Figure 2 This is a schematic diagram of the bending direction of the fan blades in this invention; Figure 3 This is a complete structural schematic diagram of the present invention; Figure 4 This is a complete structural schematic diagram of the present invention from another perspective; Figure 5 This is a diagram showing the air intake and exhaust directions when the invention is reversed; Figure 6 This is a diagram showing the air intake and exhaust directions when the invention is rotating forward.

[0015] Explanation of key component symbols: In the diagram: 1. Shaft; 2. Fan blade; 21. Inner end; 211. Connecting section; 212. Extension section; 22. Outer end; 23. Upper end; 24. Lower end. Detailed Implementation

[0016] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided.

[0017] Please see Figure 1-6 A structure that simultaneously improves the airflow of centrifugal forward and reverse fan blades includes a fan body, the fan body including a rotating shaft and a plurality of fan blades 2 connected to the rotating shaft, each of the fan blades 2 including an inner end 21 and an outer end 22, the inner end 21 including a connecting section 211 and an extension section 212, the connecting section 211 being formed by a connecting line between the fan blade 2 and the rotating shaft, the extension section 212 being formed by a curve located above the connecting line, and the outer end 22 being formed by the edge contour of the fan blade 2 away from the rotating shaft; Specifically, the rotating shaft is cylindrical, and the side edge of the cylindrical rotating shaft is used to connect with several fan blades 2. The upper and lower surfaces of the cylinder are both flat and parallel to each other. At this time, the upper and lower surfaces of the cylindrical rotating shaft are parallel to the air outlet surface. For the fan blade 2, the inner end 21 and the outer end 22 are both curved, and the bending directions of the connecting section 211 and the outer end 22 are opposite. The fan blade 2 is composed of a continuous curved surface structure from the inner end 21 to the outer end 22. Since the fan blade 2 is an arc surface extending from the shaft, it has an edge contour. In this design, there are four edge contour lines of the fan blade 2: the inner end 21 close to the shaft, the outer end 22 away from the shaft, the upper end 23 parallel to the upper surface of the shaft, and the lower end 24 parallel to the lower end 24 of the shaft. Meanwhile, there is a connecting part between the inner end 21 of the fan blade 2 and the rotating shaft, and the connecting part is a curve, which is referred to as the connecting segment 211 of the inner end 21. Meanwhile, in order to increase the area of ​​a single fan blade 2, the fan blade 2 has a part that is higher than the shaft. The outline of the part that is higher than the shaft is also higher than the shaft and is not connected to the shaft. This part of the outline is called the extension segment 212 of the inner end 21. At this time, the fan blade 2 is composed of a continuous curved surface structure from the inner end 21 to the outer end 22; The outer end 22 curve bends in the direction of rotation of the fan blade 2 when rotating forward, that is, the opening of the outer end 22 curve faces the direction of rotation of the fan blade 2 when rotating backward. Conversely, the inner end 21 connecting section 211 bends in the direction of rotation of the fan blade 2 when rotating backward, that is, the opening of the inner end 21 connecting section 211 faces the direction of rotation of the fan blade 2 when rotating forward. Since the fan blade 2 is composed of a continuous curved surface structure from the inner end 21 to the outer end 22, the fan blade 2 naturally includes two interconnected sections, referred to as the inner section and the outer section. The inner section is closer to the axis of rotation than the outer section. The inner section and the outer section are two arc-shaped plate structures with opposite concave directions, and there is a smooth transition between the inner section and the outer section. The concave direction of the inner section is consistent with that of the connecting section 211, both facing the rotation direction of the fan blade 2 when rotating in reverse. The concave direction of the outer section is consistent with that of the outer end 22, both facing the rotation direction of the fan blade 2 when rotating in forward. Using the plane perpendicular to the tangent at the midpoint of the upper end 23 as the reference plane, the projections of the inner end 21 and the outer end 22 onto the reference plane are both arcs, and the orientation of the projected arcs is the same as the orientation of the body arc. At this time, the bending direction or opening direction of the two projected arcs are opposite. When the fan blade 2 is rotated in reverse, the inner section bends in the direction of rotation of the fan blade 2. That is, there is a curved surface protruding in the direction of rotation at the inner end 21 of the fan blade 2. This reduces the suction force of the inner end 21 of the fan blade 2 on the air at the axis 1. Since the air is mainly discharged from the axis 1 part when the fan blade 2 is rotated in reverse, the effect of the innermost side in absorbing the air is weakened, which reduces the weakening effect on the air discharge and thus increases the air discharge volume when the fan blade 2 is rotated in reverse. When rotating forward, the airflow is absorbed from the top and diffuses to the surroundings. Since the inner section is curved in the direction of rotation of the fan blade 2 when rotating in reverse, that is, there is a concave curved surface at the inner end 21 of the fan blade 2 facing the direction of rotation, the airflow escapes from the inner end 21, and the suction force of the inner end 21 of the fan blade 2 on the air at the axis 1 is increased. Therefore, the air intake of the inner end 21 is increased when rotating forward, and the air output is increased when rotating forward. By setting the bending direction of the connecting section 211 of the inner end 21 formed by the connecting line of the fan blade 2 near the rotating shaft to be opposite to the bending direction of the edge of the fan blade 2 away from the rotating shaft, compared with the scheme where the inner end 21 and the outer end 22 have the same bending direction, the effect of the innermost side of the fan blade 2 in drawing out the air is weakened when rotating in reverse, reducing the weakening effect on the air outlet, thereby increasing the air outlet volume when rotating in reverse. At the same time, since the inner end 21 of the fan blade 2 has a concave curved surface facing the direction of rotation when rotating in the forward direction, the air intake volume of the inner end 21 is increased when rotating in the forward direction, thereby increasing the air outlet volume when rotating in the forward direction.

[0018] Regarding the inner curvature of the connecting segment 211 at the inner end 21, the inventors obtained the following data based on actual experiments: Among them, bending in the same direction means that the inner end 21 and the outer end 22 have the same bending direction, while bending in opposite directions means that the connecting section 211 and the outer end 22 have opposite bending directions, which is this scheme. It can be seen that the air volume increase in both forward and reverse rotation is greatest when the inner curvature is 30~35. Therefore, by setting the inner curvature of the inner end 21 connecting section 211 to 30~35, compared with the scheme where the inner end 21 and the outer end 22 have the same curvature direction, a greater improvement in the air volume in both forward and reverse rotation is achieved, further ensuring the air volume in both forward and reverse rotation. The upper end 23 and the lower end 24 of the fan blade 2 are both curved, and the upper end 23 and the lower end 24 are both parallel to the air outlet surface; The outer radius of any one of the fan blades 2 is 65~75mm, the inner radius is 16~20mm, and the forward sweep angle of any one of the fan blades 2 is 37~43°. According to the inventor's experimental results, when the outer radius is greater than 75mm, when the fan blade 2 is rotating in reverse, under the action of centrifugal force, the fan blade 2 will face greater resistance in the process of drawing air from all sides and expelling air upwards, making it difficult for the fan blade 2 to rotate in reverse and resulting in a smaller air volume; when the outer radius is greater than 75 and the inner radius is less than 16, the vibration of the fan blade 2 during rotation will continue to increase as the length of the fan blade 2 increases; and when the outer radius is less than 65 and the inner radius is greater than 20, the air volume will decrease rapidly. Therefore, by setting the outer radius of the fan blade 2 to 65~75mm and the inner radius to 16~20mm, the situation of low air volume due to excessive radius is prevented, while reducing the structural instability caused by excessive weight of the fan blade 2. Furthermore, the decrease in air volume caused by excessively small fan blade 2 is also avoided. Working principle and usage process of this invention: When the fan blade 2 is rotated in reverse, the inner section bends in the direction of rotation of the fan blade 2. That is, there is a curved surface protruding in the direction of rotation at the inner end 21 of the fan blade 2. This reduces the suction force of the inner end 21 of the fan blade 2 on the air at the axis 1. Since the air is mainly discharged from the axis 1 part when the fan blade 2 is rotated in reverse, the effect of the innermost side in absorbing the air is weakened, which reduces the weakening effect on the air discharge and thus increases the air discharge volume when the fan blade 2 is rotated in reverse. When rotating forward, the airflow is absorbed from the top and diffuses to the surroundings. Since the inner section is curved in the direction of rotation of the fan blade 2 when rotating in reverse, that is, there is a concave curved surface at the inner end 21 of the fan blade 2 facing the direction of rotation, the airflow escapes from the inner end 21, and the suction force of the inner end 21 of the fan blade 2 on the air at the axis 1 is increased. Therefore, the air intake of the inner end 21 is increased when rotating forward, and thus the air output is increased when rotating forward.

[0019] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A structure that simultaneously increases the airflow of centrifugal fan blades in both forward and reverse rotation, characterized in that: The fan body includes a rotating shaft and a plurality of fan blades connected to the rotating shaft. Each fan blade includes an inner end and an outer end. The inner end includes a connecting section and an extension section. The connecting section is formed by the connecting line between the fan blade and the rotating shaft. The extension section is formed by a curve located above the connecting line. The outer end is formed by the edge contour of the fan blade away from the rotating shaft. Both the inner and outer ends are curved, and the connecting section and the outer end bend in opposite directions, with the outer end bending in the direction of the fan blades when rotating forward. The inner curvature of the inner end curve is 30~35. The fan blade includes an inner section and an outer section connected to each other. The inner section and the outer section are two arc-shaped plate structures with opposite concave directions, which are integrally formed. The inner section is closer to the pivot than the outer section, and there is a smooth transition between the inner section and the outer section. The outer radius of any of the fan blades is 65~75mm, and the inner radius is 16~20mm.

2. The structure for simultaneously increasing the air volume of centrifugal fan blades in both forward and reverse rotation according to claim 1, characterized in that: The fan blade also includes an upper end and a lower end, both of which are curved and are parallel to the air outlet surface.

3. The structure for simultaneously increasing the air volume of centrifugal fan blades in both forward and reverse rotation according to claim 1, characterized in that: The sweep angle of any of the aforementioned fan blades is 37~43°.

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