Air outlet device for axial flow fan

Abstract

The utility model relates to the technical field of fans, in particular to an air outlet device for an axial flow fan, which comprises an air guide ring and a fan cover, the fan cover comprises a hub and a plurality of annular rings, the annular rings are connected with the air guide ring and the hub, the annular rings are arranged at intervals along the radial direction of the hub or the air guide ring, and each annular ring is positioned between the air guide ring and the hub; the section of the annular ring in the radial direction of the air guide ring or the hub is of a structure with the airflow guiding and rectifying functions, so that the annular ring has the airflow guiding and dispersing functions. Therefore, when air generated when the fan does work is exhausted from the fan cover, irregular or disordered airflow can be adjusted into stable and ordered airflow through the annular ring, so that the purpose of airflow rectification is achieved, and the effects of efficiency improvement and noise reduction of the fan are further achieved.

Description

Technical Field

[0001] This utility model relates to the field of fan technology, and in particular to an air outlet device for an axial flow fan. Background Technology

[0002] Axial flow fans have been widely used in various industries, such as refrigeration, HVAC, ventilation, and coal mining. Currently, axial flow fans on the market now include air outlet devices with guide vanes. For example, patent publication number CN212106365U discloses a serializable axial flow fan guide vane device, which includes "an outer guide vane disk, multiple middle guide vane disks, and an inner guide vane disk; guide vanes are fixedly connected between the outer and inner guide vane disks; multiple middle guide vane disks are fixedly connected to the guide vanes; and the outer guide vane disk is flared outwards in a trumpet shape." This design offers technical benefits such as "allowing the air that has been powered by the fan to flow out through the guide vanes and then be further distributed and guided by the middle guide vane disks, significantly improving the fan's range, efficiency, and other performance characteristics."

[0003] However, during use, the aforementioned serializable axial flow fan guide vane device cannot guide and rectify airflow because the inner disk of the guide vane is annular, that is, the cross-section of the inner disk of the guide vane (hereinafter referred to as the annular ring) in the radial direction of the inner disk of the guide vane (hereinafter referred to as the hub) or the outer disk of the guide vane (hereinafter referred to as the guide ring) is circular. This results in increased fan noise and affects the fan noise reduction effect. Utility Model Content

[0004] One of the objectives of this utility model is to provide an air outlet device for an axial flow fan, which aims to solve the technical problem mentioned in the background art where the cross-section of the annular ring in the radial direction of the air guide ring is circular, which cannot play the role of guiding and rectifying airflow, thereby increasing the noise of the fan and affecting the noise reduction of the fan.

[0005] To achieve the above objectives, this utility model provides an air outlet device for an axial flow fan, including an air guide ring and an air shroud. The air shroud includes a hub and multiple annular rings. The annular rings are connected to the air guide ring and the hub. The multiple annular rings are arranged at radial intervals along the hub or the air guide ring, and each annular ring is located between the air guide ring and the hub. The cross-section of the annular ring in the radial direction of the air guide ring or the hub has a structure that guides and rectifies the airflow.

[0006] Furthermore, the cross-section of the annular ring in the radial direction of the air guide ring or hub is elliptical.

[0007] Furthermore, the cross-section of the annular ring in the radial direction of the air guide ring or hub is an airfoil.

[0008] Furthermore, the cross-section of the annular ring in the radial direction of the air guide ring or hub is a closed-loop structure formed by connecting two circular arcs.

[0009] Furthermore, multiple guide vanes are provided between the air guide ring and the hub. The opposite ends of the guide vanes are respectively connected and fixed to the inner wall of the air guide ring and the outer wall of the hub. The multiple guide vanes are spaced apart along the circumference of the air guide ring. The annular ring penetrates the opposite surfaces of the guide vanes.

[0010] Furthermore, the guide vane, air guide ring, hub, and multiple annular rings are integrally formed.

[0011] Furthermore, the major axis of the ellipse is parallel to the axial direction of the hub.

[0012] Furthermore, the spacing between any two adjacent annular rings is equal; or, the spacing between multiple annular rings gradually decreases or gradually increases radially outward from the hub.

[0013] Furthermore, the guide vane has an angle β between its airfoil chord direction and the major axis of the ellipse, where -10°≤β≤10°; and -3°≤β≤0°.

[0014] Furthermore, the major axis of the ellipse is set as Lh, and the minor axis of the ellipse is set as Lm. The relationship between Lm and Lh is: 2mm≤Lm≤0.25Lh.

[0015] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0016] In use, the air outlet device for the axial flow fan of this utility model, due to the connection between the annular rings and the guide rings and the hub, with multiple annular rings arranged radially at intervals along the hub or guide ring, and the airflow of the axial flow fan being discharged along the axial direction of the guide ring, allows the annular rings on the fan shroud to be configured with a structure that guides and rectifies the airflow in the radial direction of the guide ring or hub. Thus, when the air used by the axial flow fan is discharged from the fan shroud along the axial direction of the guide ring, the annular rings can adjust the irregular or turbulent airflow into a stable and orderly airflow, thereby achieving the purpose of rectifying the airflow and ultimately improving the efficiency and reducing noise of the fan. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the air outlet device for the axial flow fan of this utility model.

[0018] Figure 2 This is a front view of the air outlet device for an axial flow fan.

[0019] Figure 3 for Figure 2 Enlarged structural diagram at point C;

[0020] Figure 4 for Figure 3Sectional view at point BB;

[0021] Figure 5 for Figure 2 Enlarged structural diagram at point AA;

[0022] Figure 6 for Figure 5 Enlarged structural diagram at point D;

[0023] Figure 7 This is a schematic diagram of the airfoil portion of the guide vane in an embodiment of the present utility model;

[0024] Figure 8 This is a schematic diagram of the cross-section of the annular ring in this embodiment of the utility model, which is an airfoil structure.

[0025] Figure 9 The cross-section of the annular ring in this embodiment of the present invention is a schematic diagram of a closed-loop structure formed by connecting two circular arcs.

[0026] Numbering in each attached figure:

[0027] 1. Air guide ring; 10. Receiving cavity; 11. Connecting cavity; 12. Connecting surface; 2. Hub; 3. Annular ring; 4. Guide vane; 40. Airfoil section; 5. Airfoil chord direction. Detailed Implementation

[0028] It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0029] In the description of this utility model, it should be understood that the terms "width", "upper", "lower", "front", "rear", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0030] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, a direct connection, or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0031] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0032] Please refer to Figure 1 - Figure 7 This utility model provides an air outlet device for an axial flow fan, including an air guide ring 1 and a wind cover and multiple guide vanes 4. The wind cover includes a hub 2 and multiple annular rings 3, and the annular rings 3 are connected to the air guide ring 1 and the hub 2 through the guide vanes 4. Specifically, the multiple guide vanes 4 are arranged at intervals along the circumference of the air guide ring 1, and the opposite ends of the guide vanes 4 are respectively connected and fixed to the inner wall of the air guide ring 1 and the outer wall of the hub 2; while the multiple annular rings 3 are arranged at intervals along the radial direction of the hub 2 or the air guide ring 1, and each annular ring 3 is located between the air guide ring 1 and the hub 2, and the annular rings 3 penetrate the opposite surface of the guide vanes 4; the guide vanes 4, the air guide ring 1, the hub 2 and the multiple annular rings 3 are integrally formed, which can save the assembly process between the guide vanes 4, the air guide ring 1, the hub 2 and the annular rings 3; the material for the integral forming of the guide vanes 4, the air guide ring 1, the hub 2 and the annular rings 3 can be metal or nylon and other polymer materials or a mixture thereof. In addition, the cross section of the annular ring 3 in the radial direction of the air guide ring 1 or the hub 2 is a structure that guides and straightens the airflow.

[0033] In application, the air outlet device of this invention is installed at the air outlet port of the impeller of the axial flow fan, and the fitting depth between the guide ring 1 and the impeller is determined, while maintaining the gap between the outer wall of the impeller and the guide ring 1. The guide ring 1 primarily serves to guide the airflow.

[0034] In summary, since the annular ring 3 is connected to the guide ring 1 and the hub 2, and multiple annular rings 3 are arranged radially at intervals along the hub 2 or the guide ring 1, while the airflow of the axial flow fan is discharged along the axial direction of the guide ring 1, setting the cross-section of the annular ring 3 on the fan shroud in the radial direction of the guide ring 1 or the hub 2 to have the function of guiding and rectifying the airflow allows the annular ring 3 to guide and disperse the airflow in the direction of airflow discharge. Thus, when the air that the axial flow fan is working on is discharged from the fan shroud along the axial direction of the guide ring 1, the annular ring 3 can adjust the irregular or turbulent airflow into a stable and orderly airflow, thereby achieving the purpose of rectifying the airflow and thus achieving the effect of improving fan efficiency and reducing noise.

[0035] In one embodiment, the annular ring 3 has an elliptical cross-section in the radial direction of the guide ring 1 or hub 2. This elliptical shape helps reduce noise generated by the axial flow fan. This is primarily because the elliptical shape better guides the airflow along the exhaust direction, reducing turbulence and collisions, thus lowering noise. Furthermore, the major axis of the ellipse is parallel to the axial direction of the hub 2 or guide ring 1, which increases the time the ellipse guides the airflow, further enhancing noise reduction.

[0036] It should be emphasized that the cross section of the annular ring 3 in the radial direction of the guide ring 1 or the hub 2 is elliptical, which can minimize the impact loss of the airflow coming out of the impeller of the fan along the axial direction of the guide ring 1 and reduce the intensity of the wake vortex formed at the outlet of the shroud, thereby achieving the purpose of improving efficiency and reducing noise. Compared with the traditional shroud, the shroud with the above structure adopted in this utility model has greatly improved efficiency and noise performance.

[0037] Of course, in other embodiments, such as Figure 8 As shown, the cross-section of the annular ring 3 in the radial direction of the guide ring 1 or the hub 2 is an airfoil, or, as... Figure 9 As shown, the annular ring 3 has a radial cross-section in the air guide ring 1 or hub 2 that is a closed-loop structure formed by connecting two circular arcs (i.e., the closed-loop structure is formed by connecting two circular arcs). This allows the annular ring 3 to guide and disperse airflow in the direction of airflow discharge. Therefore, for those skilled in the art, by reasonably modifying the structure of the radial cross-section of the annular ring 3 in the air guide ring 1 or hub 2, it should also fall within the protection scope of this utility model.

[0038] Wherein, the major axis of the ellipse is set as Lh, and the minor axis of the ellipse is set as Lm; for example Figure 5 and Figure 6 As shown, the airfoil portion 40 of the guide vane 4 faces away from the air outlet of the shroud. The chord length of the airfoil 4 (which refers to the chord length of the airfoil portion 40 of the guide vane 4) is set to Ln; Lh and Ln satisfy the relationship: 5mm ≤ Lh ≤ Ln; Lm and Lh satisfy the relationship: 2mm ≤ Lm ≤ Lh. Where 2mm ≤ Lm ≤ 0.25Lh. For example, Ln is 16mm, Lh is 5mm, and Lm is 2mm. In another example, Ln is 16mm, Lh is 16mm, and Lm is 4mm.

[0039] In one embodiment, the spacing between any two adjacent annular rings 3 is equal, thus ensuring uniform airflow. Of course, in other embodiments, the spacing between the plurality of annular rings 3 gradually decreases or increases radially outward from the hub 2. Those skilled in the art can reasonably change the spacing between the plurality of annular rings 3 according to actual working conditions, and no limitation is made here.

[0040] In one embodiment, the airfoil chord direction 5 of the guide vane 4 forms an angle β with the major axis of the ellipse, where -10° ≤ β ≤ 10°; and -3° ≤ β ≤ 0°. Specifically, as shown... Figure 4 As shown, the included angle β in this embodiment is -3°, which can reduce the airflow angle of attack, thereby allowing the airflow to flow more smoothly over the guide vane 4, reducing the generation of vortices and resistance, and thus improving the efficiency of the fan.

[0041] Of course, in other embodiments, the included angle β can also be 0° or 1°. When the included angle β is 0°, the tangent of the airfoil chord of the guide vane 4 is parallel to the major axis of the ellipse.

[0042] In one embodiment, reference is made to Figure 5 The cavity on the guide ring 1 for engaging with the impeller is designated as a receiving cavity 10, and the cavity on the guide ring 1 for fixing and connecting the guide vane 4 is designated as a connecting cavity 11. The inner diameter of the receiving cavity 10 is larger than the inner diameter of the connecting cavity 11, and the end face on the connecting cavity 11 that connects to the receiving cavity 10 is designated as a connecting surface 12. While ensuring the clearance between the outer wall of the impeller and the guide ring 1, the inner wall surface of the receiving cavity 10 and the connecting surface 12 are rounded. Figure 7 As shown, the radius of the fillet is R. The fillet can reduce the backflow of airflow from the gap between the inner wall of the receiving cavity 10 and the blade tip of the impeller, thereby reducing blade tip leakage (blade tip leakage refers to the phenomenon where, under the action of the pressure difference between the pressure surface and suction surface of the blade, some airflow flows from the pressure surface of the blade into the gap between the inner wall of the receiving cavity 10 and the blade of the impeller, and is accelerated through the gap to form leakage flow, which is called blade tip leakage).

[0043] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. Any equivalent structural or procedural transformations made based on the content of the present utility model specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present utility model.

Claims

1. An air outlet device for an axial flow fan, comprising an air guide ring and an air shroud, the air shroud comprising a hub and a plurality of annular rings, the annular rings being connected to the air guide ring and the hub, the plurality of annular rings being arranged at radial intervals along the hub or the air guide ring, and each annular ring being located between the air guide ring and the hub; characterized in that, The annular ring has a cross-section in the radial direction of the air guide ring or hub that has the function of guiding and rectifying airflow.

2. The air outlet device for an axial flow fan according to claim 1, characterized in that, The cross-section of the annular ring in the radial direction of the air guide ring or hub is elliptical.

3. The air outlet device for an axial flow fan according to claim 1, characterized in that, The annular ring has an airfoil-shaped cross-section in the radial direction of the air guide ring or hub.

4. The air outlet device for an axial flow fan according to claim 1, characterized in that, The annular ring has a closed-loop structure in the radial direction of the air guide ring or hub, which is formed by connecting two circular arcs.

5. The air outlet device for an axial flow fan according to claim 2, characterized in that, Multiple guide vanes are provided between the air guide ring and the hub. The opposite ends of the guide vanes are respectively connected and fixed to the inner wall of the air guide ring and the outer wall of the hub. The multiple guide vanes are arranged at intervals along the circumference of the air guide ring. The annular ring penetrates the opposite surfaces of the guide vanes.

6. The air outlet device for an axial flow fan according to claim 5, characterized in that, The guide vanes, air guide rings, hub, and multiple annular rings are integrally formed.

7. The air outlet device for an axial flow fan according to claim 2, characterized in that, The major axis of the ellipse is parallel to the axial direction of the hub.

8. The air outlet device for an axial flow fan according to any one of claims 1-7, characterized in that, The spacing between any two adjacent rings is equal; or, the spacing between multiple rings gradually decreases or increases radially outward from the hub.

9. The air outlet device for an axial flow fan according to claim 5, characterized in that, The guide vane has an angle β between its airfoil chord and the major axis of the ellipse, where -10°≤β≤10°; and -3°≤β≤0°.

10. The air outlet device for an axial flow fan according to claim 7, characterized in that, The major axis of the ellipse is set as Lh, and the minor axis of the ellipse is set as Lm. The relationship between Lm and Lh is: 2mm≤Lm≤0.25Lh.

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