Fan structure

Abstract

The utility model provides a fan structure. The fan structure comprises a center hub and a plurality of blades. A plurality of reinforcing ribs which are arranged at intervals are arranged on the circumferential outer surface of the central hub, and the blades are arranged on the central hub through the reinforcing ribs; the protruding height of the reinforcing ribs on the circumferential outer surface is gradually reduced in the direction from the front edge portion of the corresponding blade to the rear edge portion of the corresponding blade. The technical problems that due to the fact that the blade root (especially the front edge area) bears the composite effect of centrifugal force and aerodynamic loads, front edge local stress concentration is likely to be caused, microcracks are induced, and fatigue fracture is accelerated are solved. Particularly, under the working conditions of high rotating speed or frequent start and stop, the joints of the blades and the hub become structural weak points, and the service life of the fan is remarkably shortened.

Description

Technical Field

[0001] This utility model relates to the field of fan technology, and more specifically, to a fan structure. Background Technology

[0002] In industrial fans, heat dissipation equipment, and aerodynamic devices, the fan is a core component, and its structural reliability, aerodynamic efficiency, and service life directly affect the system performance.

[0003] Specifically, because the blade root (especially the leading edge region) is subjected to the combined effects of centrifugal force and aerodynamic load, local stress concentration at the leading edge is easily caused, inducing microcracks and accelerating fatigue fracture. Especially under high speed or frequent start-stop conditions, the connection between the blade and the hub becomes a structural weak point, significantly shortening the fan's lifespan. Summary of the Invention

[0004] The technical problem solved by this invention is that the root of the blade (especially the leading edge region) is subjected to the combined effects of centrifugal force and aerodynamic load, which easily leads to local stress concentration at the leading edge, inducing microcracks and accelerating fatigue fracture. Especially under high speed or frequent start-stop conditions, the connection between the blade and the hub becomes a weak point in the structure, significantly shortening the life of the fan.

[0005] To solve the above problems, this utility model provides a fan structure, which includes a central hub and multiple blades; the circumferential outer surface of the central hub is provided with multiple reinforcing ribs arranged at intervals, and the multiple blades are arranged on the central hub through the multiple reinforcing ribs; wherein, the height of the protrusion of the reinforcing ribs on the circumferential outer surface gradually decreases from the leading edge to the trailing edge of the corresponding blade.

[0006] Compared with existing technologies, the technical effects achieved by this solution are as follows: By setting reinforcing ribs on the circumferential outer surface, the structural strength of the connection between the blades and the central hub is ensured, thereby extending the service life of the fan structure. Specifically, considering the structural characteristics of the reinforcing ribs on the central hub, they are adapted to the stress conditions of the blades during fan rotation. Specifically, the protrusion height of the reinforcing ribs on the central hub for mating with the leading edge is higher than the protrusion height of the reinforcing ribs on the central hub for mating with the trailing edge. This ensures that the connection strength between the blades and the central hub is improved by adding reinforcing ribs, while avoiding setting the protrusion height of the reinforcing ribs at the same height, which would unnecessarily increase the weight of the fan structure. Furthermore, the gradually changing protrusion height of the reinforcing ribs reduces the difficulty of demolding the cast fan structure.

[0007] In one embodiment of this utility model, the reinforcing ribs are matched with the blades one by one, and the reinforcing ribs and blades are matched with an arc-shaped transition; the shape of the upper end of the reinforcing rib is adapted to the upper end of the blade, and the lower end of the reinforcing rib extends to the edge of the central hub.

[0008] Compared with existing technologies, the technical effects achieved by adopting this technical solution are as follows: by making the stiffener and the blade have an arc transition fit, specifically the included angle between the two is a rounded chamfer, the impact of stress concentration is reduced.

[0009] In one embodiment of this utility model, the radius of curvature of the leading edge ranges from R2 to R4; and / or, the trailing edge has a sharp edge structure, and the thickness of the trailing edge ranges from 0.3 mm to 0.5 mm.

[0010] In one embodiment of this utility model, a composite coating is provided at the leading edge; wherein the composite coating comprises polyurethane-nano Al2O3, and the thickness of the composite coating ranges from 80μm to 120μm.

[0011] Compared with existing technologies, the technical effect achieved by adopting this technical solution is: to improve the surface hardness of the blades through plasma spraying.

[0012] In one embodiment of this utility model, the central hub has a first end and a second end arranged opposite to each other; the first end is open so that the central hub forms an installation space for mounting the rotor of the drive motor; the second end has multiple connecting holes that cooperate with multiple fixing holes on the rotor.

[0013] In one embodiment of this utility model, the central hub is provided with an annular protrusion structure for fixing the rotor, and the annular protrusion structure is positioned opposite to the area composed of multiple connecting holes; the second end is also provided with a mating shaft hole that mates with the drive shaft hole of the rotor, and the multiple connecting holes are arranged at equal intervals around the axis of the mating shaft hole.

[0014] Compared with existing technologies, the technical effect achieved by adopting this technical solution is: by setting an annular protrusion structure, the installation stability of the rotor is improved.

[0015] In one embodiment of this utility model, a positioning groove is provided at the position corresponding to the second end, and the positioning groove is used to assemble the fixing cover; the fixing cover is provided with mating holes that mate with a plurality of connecting holes one by one; wherein, the mating holes, connecting holes and fixing holes are connected in sequence by fasteners to fix the rotor to the center hub.

[0016] Compared with existing technologies, the technical effect achieved by adopting this technical solution is to improve the stability of the installed rotor.

[0017] In one embodiment of this utility model, the number of blades is denoted as n; where 6≤n≤12.

[0018] In one embodiment of this utility model, the central hub and multiple blades are integrally die-cast.

[0019] Compared to existing technologies, the technical advantages of this solution are as follows: It integrates the central hub, blades, and reinforcing ribs of the fan structure into a single integral structure, eliminating bolt, weld, or adhesive joints and reducing assembly complexity. Furthermore, unlike separate structures where joints and bolt holes are prone to stress concentration points, this integrated die-cast design avoids such defects, improving fatigue life. The integrated design also ensures material consistency for all components of the fan structure, effectively reducing defects such as porosity and shrinkage within the integral metal flow forming process.

[0020] By adopting the technical solution of this utility model, the following technical effects can be achieved:

[0021] (1) By setting reinforcing ribs on the circumferential outer surface, the structural strength of the connection between the blades and the central hub is ensured, thereby extending the service life of the fan structure. Specifically, considering the structural characteristics of the reinforcing ribs on the central hub, they are adapted to the stress conditions of the blades during the rotation of the fan structure. This is manifested in that the height of the reinforcing ribs on the central hub for mating with the leading edge is higher than the height of the reinforcing ribs on the central hub for mating with the trailing edge. While ensuring that the connection strength between the blades and the central hub is improved by adding reinforcing ribs, it is avoided to set the height of the reinforcing ribs at the same height, which would increase the unnecessary weight of the fan structure. In addition, by utilizing the characteristic of the gradually changing height of the reinforcing ribs, the demolding difficulty of the cast fan structure is reduced.

[0022] (2) The central hub, blades, and reinforcing ribs of the fan structure are combined into a single integral structure, eliminating bolt, weld, or adhesive joints and reducing assembly complexity. In addition, compared to the split structure, the joints and bolt holes are prone to stress concentration points. The integrated design of integral die casting avoids such defects and improves fatigue life. Moreover, the integrated design ensures the consistency of materials for all parts of the fan structure and effectively reduces defects such as porosity and shrinkage inside the integral metal flow forming. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of a fan structure provided in an embodiment of the present utility model;

[0025] Figure 2 for Figure 1 A structural diagram from another perspective;

[0026] Figure 3 for Figure 1 A structural diagram from another perspective;

[0027] Figure 4 for Figure 1 A structural diagram from another perspective;

[0028] Figure 5 for Figure 4 Enlarged view of point A in the middle;

[0029] Figure 6 for Figure 1 A structural diagram from another perspective;

[0030] Figure 7 for Figure 6 Enlarged view of point B in the middle.

[0031] Explanation of reference numerals in the attached figures:

[0032] 100. Fan structure; 10. Center hub; 101. Installation space; 11. First end; 12. Second end; 121. Connecting hole; 122. Annular protrusion structure; 123. Fitting shaft hole; 124. Positioning groove; 20. Blade; 21. Leading edge; 22. Trailing edge; 23. Upper root of blade; 24. Lower root of blade; 30. Reinforcing rib; 31. Upper end; 32. Lower end. Detailed Implementation

[0033] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0034] See Figure 1 This is a structural schematic diagram of a fan structure 100 provided in an embodiment of the present utility model. Combined with... Figures 2-7 The fan structure 100 includes a central hub 10 and multiple blades 20; the circumferential outer surface of the central hub 10 is provided with multiple reinforcing ribs 30 arranged at intervals from each other, and the multiple blades 20 are arranged on the central hub 10 through the multiple reinforcing ribs 30; wherein, the height of the protrusion of the reinforcing ribs 30 on the circumferential outer surface gradually decreases from the leading edge 21 of the corresponding blade 20 to the trailing edge 22.

[0035] By providing reinforcing ribs 30 on the circumferential outer surface, the structural strength of the connection between the blades 20 and the central hub 10 is ensured, thereby extending the service life of the fan structure 100. Specifically, considering the structural characteristics of the reinforcing ribs 30 on the central hub 10, they are adapted to the stress conditions of the blades 20 during the rotation of the fan structure 100. This is manifested in the fact that the height of the protrusion of the reinforcing ribs 30 on the central hub 10 for engaging with the leading edge 21 is higher than the height of the protrusion of the reinforcing ribs 30 on the central hub 10 for engaging with the trailing edge 22. While ensuring that the connection strength between the blades 20 and the central hub 10 is improved by adding reinforcing ribs 30, it avoids setting the protrusion height of the reinforcing ribs 30 at the same height, which would increase the unnecessary weight of the fan structure 100. In addition, by utilizing the gradually changing protrusion height of the reinforcing ribs 30, the demolding difficulty of casting the fan structure 100 is reduced.

[0036] Combination Figures 5-7 Preferably, the reinforcing rib 30 and the blade 20 are fitted one-to-one, and the reinforcing rib 30 and the blade 20 are fitted with an arc-shaped transition; the shape of the upper end 31 of the reinforcing rib 30 is adapted to the upper end 31 of the blade 20, and the lower end 32 of the reinforcing rib 30 extends to the edge of the central hub 10. For example, for ease of understanding, the part of the blade 20 used to connect with the reinforcing rib 30 can be divided into an upper root 23 and a lower root 24, wherein the upper root 23 is connected to the upper end 31, and the lower root 24 is connected to the lower end 32.

[0037] Preferably, the radius of curvature of the leading edge 21 is in the range of R2-R4; and / or, the trailing edge 22 has a cutting edge structure, and the thickness of the trailing edge 22 is in the range of 0.3mm-0.5mm. This thickness range is denoted as d.

[0038] Preferably, the leading edge 21 is provided with a composite coating; wherein the composite coating comprises polyurethane-nano Al2O3, and the thickness of the composite coating ranges from 80μm to 120μm. For example, by using a plasma spraying process, the surface hardness of the blade 20 can be ensured to reach HV800 or higher.

[0039] Preferably, the center hub 10 has a first end 11 and a second end 12 disposed opposite to each other; the first end 11 is open so that the center hub 10 forms a mounting space 101 for mounting the rotor of the drive motor; the second end 12 has a plurality of connecting holes 121 that cooperate with a plurality of fixing holes on the rotor.

[0040] Preferably, the central hub 10 is provided with an annular protrusion structure 122 for fixing the rotor, and the annular protrusion structure 122 is arranged opposite to the area composed of multiple connecting holes 121; the second end 12 is also provided with a mating shaft hole 123 that mates with the drive shaft hole of the rotor, and the multiple connecting holes 121 are arranged at equal intervals around the axis of the mating shaft hole 123.

[0041] Preferably, a positioning groove 124 is provided at the position corresponding to the second end 12, and the positioning groove 124 is used to assemble the fixing cover; the fixing cover is provided with mating holes that mate with a plurality of connecting holes 121 one by one; wherein, the mating holes, connecting holes 121 and fixing holes are connected in sequence by fasteners to fix the rotor to the center hub 10.

[0042] Preferably, the number of leaves 20 is denoted as n; where 6 ≤ n ≤ 12. For example, the number of leaves 20 can be 7.

[0043] Preferably, the central hub 10 and multiple blades 20 are integrally die-cast.

[0044] Specifically, the common fan blade manufacturing technologies currently on the market can be divided into the following types: split welding / riveting structure, injection molding process and traditional die casting process.

[0045] In the manufacturing method of the split-type welded / riveted junction, the blade 20 and the hub need to be machined separately first, and then assembled by welding, riveting or bolting. Although this process is simple and easy to implement, it has obvious structural defects. Stress concentration is prone to occur at the connection points, which can easily lead to fatigue fracture during long-term high-speed operation. In addition, it is difficult to guarantee assembly accuracy, and the fit clearance between the components will affect the continuity of airflow, resulting in a decrease in aerodynamic performance.

[0046] Furthermore, injection molding is primarily used in the manufacture of plastic fan blades. While this process allows for the one-time molding of complex shapes, the strength limitations of plastic materials result in poor load-bearing capacity and temperature resistance. Under high-temperature or high-speed operating conditions, plastic fan blades are prone to deformation and aging, leading to a shorter lifespan.

[0047] Therefore, in contrast, the technical solution of this application utilizes die casting to integrally manufacture the fan structure 100, merging the central hub 10, blades 20, and reinforcing ribs 30 of the fan structure 100 into a single integral structure, eliminating bolt, weld, or adhesive interfaces and reducing assembly complexity. Furthermore, compared to this, the joints and bolt holes of split structures are prone to becoming stress concentration points, while the integrated design through die casting avoids such defects, improving fatigue life. Moreover, the integrated design ensures the material consistency of all parts of the fan structure 100, effectively reducing defects such as internal porosity and shrinkage during integral metal flow forming.

[0048] Specifically, the center hub 10 is made of high-strength aluminum alloy (such as ADC12) or magnesium alloy and is formed in one piece by precision die casting. The center hub 10 has a high-precision shaft hole with H7 tolerance to ensure a reliable connection with the motor shaft. The outer edge of the center hub 10 adopts a streamlined transition design, with the optimal curvature determined through computational fluid dynamics (CFD) optimization, which effectively reduces airflow separation losses.

[0049] Furthermore, the number of blades 20 is designed according to application requirements, typically 6-12, and evenly distributed around the central hub 10. The leading edge adopts a blunt design with a curvature radius of R2-R4, which can delay airflow separation; the trailing edge has a sharp edge structure with a thickness controlled at 0.3mm-0.5mm to reduce wake turbulence. The blade 20's installation angle changes continuously from the hub to the blade tip, achieving optimal angle of attack distribution.

[0050] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A fan structure, characterized in that, The fan structure includes a central hub (10) and multiple blades (20); The outer circumferential surface of the central hub (10) is provided with a plurality of reinforcing ribs (30) arranged at intervals from each other, and the plurality of blades (20) are provided on the central hub (10) through the plurality of reinforcing ribs (30); The height of the reinforcing rib (30) on the circumferential outer surface gradually decreases from the leading edge (21) of the corresponding blade (20) to the trailing edge (22).

2. The fan structure according to claim 1, characterized in that, The reinforcing rib (30) is fitted to the blade (20) one by one, and the reinforcing rib (30) and the blade (20) are fitted with an arc-shaped transition. The upper end (31) of the reinforcing rib (30) is adapted to the upper end (31) of the blade (20), and the lower end (32) of the reinforcing rib (30) extends to the edge of the central hub (10).

3. The fan structure according to claim 1, characterized in that, The radius of curvature of the leading edge (21) is in the range of R2-R4; and / or the trailing edge (22) has a sharp edge structure and the thickness of the trailing edge (22) is in the range of 0.3mm-0.5mm.

4. The fan structure according to claim 1, characterized in that, The central hub (10) is provided with a first end (11) and a second end (12) that are arranged opposite to each other; The first end (11) is provided as an opening so that the central hub (10) forms a mounting space (101) for mounting the rotor of the drive motor; The second end (12) is provided with a plurality of connecting holes (121) that cooperate with a plurality of fixing holes on the rotor.

5. The fan structure according to claim 4, characterized in that, The central hub (10) is provided with an annular protrusion structure (122) for fixing the rotor, and the annular protrusion structure (122) is arranged opposite to the area composed of the plurality of connecting holes (121); The second end (12) is also provided with a mating shaft hole (123) that mates with the drive shaft hole of the rotor, and the plurality of connecting holes (121) are arranged at equal intervals around the axis of the mating shaft hole (123).

6. The fan structure according to claim 5, characterized in that, The second end (12) is provided with a positioning groove (124) corresponding to the position of the area, and the positioning groove (124) is used to assemble and fix the cover; The fixed cover is provided with mating holes that mate with the plurality of connecting holes (121) one by one; The rotor is fixed to the center hub (10) by fasteners that sequentially connect the mating hole, the connecting hole (121) and the fixing hole.

7. The fan structure according to claim 1, characterized in that, The number of blades (20) is denoted as n; Where 6≤n≤12.

8. The fan structure according to any one of claims 1-7, characterized in that, The central hub (10) and the plurality of blades (20) are integrally die-cast.

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