Self-running-in structure of fan

Abstract

The invention provides a fan self-running-in structure which comprises a fan frame provided with an annular flow channel and a fan wheel arranged in the annular flow channel. The fan wheel is provided with a plurality of fan blades, the outer end edge of each fan blade is provided with a local convex rib, the local convex rib is in local interference fit with the inner wall of a flow channel of the fan frame, local abrasion is generated between the local convex rib and the inner wall of the flow channel when the fan wheel initially operates, a groove is formed in the corresponding position of the inner wall in a running-in mode, and the local convex rib and the inner wall are in near-zero clearance or concave-convex corresponding fit. Therefore, the gap between the outer end edge of the fan blade and the inner wall of the flow channel is reduced, a relative structure close to zero gap is formed, air flow is effectively prevented from turning over from the lower portion of the fan blade to the upper portion of the fan blade, the gap vortex and resonance phenomena are reduced, and the technical effect of reducing the operation noise of the fan is achieved.

Description

Technical Field

[0001] This invention relates to a fan structure, and more particularly to a fan self-running structure designed through the self-running between the fan blades and the fan frame. Background Technology

[0002] like Figure 1 , Figure 2 As shown, a conventional fan structure 100 typically includes a fan frame 110 and a fan wheel 120 disposed inside the fan frame 110. The fan wheel 120 has a hub 122 and a plurality of fan blades 124 extending from its periphery. In this structure, an annular flow channel 112 is formed inside the fan frame 110, and an annular gap G is reserved between the fan frame 110 and the outer edge 126 of the fan blades 124 to avoid contact or interference between the fan blades 124 and the inner wall of the flow channel 112 during operation.

[0003] like Figure 3 As shown, when the fan wheel 120 rotates at high speed, the airflow will flow from the high-pressure area below the fan blade 124 through the gap G to the low-pressure area above, forming a significant gap vortex. This gap vortex not only reduces airflow efficiency but also interferes with the structure of the fan frame 110, producing vortex instability and resonance, which is the main source of high-frequency noise from the fan.

[0004] In practice, to avoid interference and jamming between the fan blade 124 and the inner wall of the fan frame 110, most fan designs still need to maintain a certain clearance tolerance between the fan blade 124 and the fan frame 110. However, this design cannot effectively suppress vortex turbulence. Although some existing technologies have attempted to add special profiles or interference structures to the fan blade tip to disturb the vortex field, most of them have failed to fundamentally improve the airflow rise and noise source problems caused by structural clearances, and often involve complex processes or precise tolerance control, making practical applications still challenging.

[0005] Therefore, the technical problem to be solved by this invention is how to provide a fan design that can actively establish a close fit between the fan blades and the inner wall of the fan frame without increasing manufacturing difficulty, thereby effectively suppressing the phenomenon of airflow reversal and resonance in the gap. Summary of the Invention

[0006] The purpose of this invention is to provide a self-running fan structure. This structure involves providing a local rib on the outer edge of the fan blade. Through the interference and rotational wear behavior between the local rib and the inner wall of the fan frame's flow channel, the local rib actively runs into the inner wall of the flow channel during operation, forming a groove. This groove forms a zero-gap or convex-concave fit structure, reducing the local gap between the outer edge of the blade and the inner wall of the flow channel. This allows the fan to operate in a near-zero-gap state, improving airflow guidance and effectively suppressing airflow turbulence. This solves the problems of airflow turbulence, gap eddies, and resonance noise caused by the need to reserve a gap between the fan blade and the fan frame in conventional fan structures.

[0007] To achieve the above objectives, the present invention provides a fan self-break-in structure, characterized in that it comprises:

[0008] A frame having an annular flow channel with an inner wall;

[0009] A fan wheel is disposed within the annular flow channel and is rotatable relative to the fan frame. The fan wheel has a plurality of fan blades, and each fan blade has at least one radially protruding partial rib at one outer end edge. The outer diameter of the at least one partial rib is substantially larger than the inner diameter of the annular flow channel so as to form partial interference with the inner wall of the flow channel.

[0010] During the initial operation of the fan wheel, the local ribs make local contact wear with the inner wall of the flow channel, forming at least one groove at the corresponding position on the inner wall of the flow channel. After the local ribs and the grooves are worn together, they can form a zero gap or a concave-convex corresponding fit.

[0011] This reduces the local gap between the outer edge of the fan blade and the inner wall of the flow channel, creating a near-zero gap configuration to suppress airflow from below the fan blade to above, thereby reducing gap vortices and lowering operating noise.

[0012] The fan self-break-in structure, wherein: the local rib has a turning angle at one front end in the fan wheel rotation direction to scrape when it first contacts the inner wall of the flow channel.

[0013] The aforementioned fan self-break-in structure, wherein the turning angle is an inclined surface or a chamfered structure.

[0014] The aforementioned fan self-break-in structure, wherein: the outer diameter of the outer edge of the fan blade is substantially equal to the inner diameter of the annular flow channel.

[0015] This invention provides a self-break-in structure for a fan, in which the fan initially makes local interference contact with the inner wall of the flow channel and undergoes wear during the initial operation phase. As the fan wheel rotates, the local rib scrapes a groove at the corresponding position on the inner wall of the flow channel. After the break-in process is complete, the local rib and the groove have a zero-gap or relatively concave-convex fit, allowing the fan wheel to rotate while maintaining radial stability.

[0016] In this invention, the local rib can be provided with an inclined surface or a chamfer at the front end of the fan wheel in the direction of rotation, forming a turning angle of attack, so that it has a scraping effect when it first contacts the inner wall of the flow channel, which helps to form a groove profile on the inner wall of the flow channel and improve the fitting accuracy.

[0017] Through the above structure, the local gap between the outer edge of the fan blade and the inner wall of the flow channel is reduced to a minimum, forming a near-zero gap relative configuration to form a guide interface for the airflow above and below the fan blade. This effectively suppresses the airflow from below the fan blade to above during fan operation, significantly reducing gap eddies and noise sources, and improving wind pressure output and static pressure efficiency. Attached Figure Description

[0018] Figure 1 This is a three-dimensional exploded view of a familiar fan;

[0019] Figure 2 This is a top view diagram of a familiar fan assembly;

[0020] Figure 3 This is a cross-sectional view of a commonly known fan assembly;

[0021] Figure 4 This is a three-dimensional exploded view of the present invention;

[0022] Figure 5 This is a partial cross-sectional view of the assembly of the present invention (before break-in);

[0023] Figure 6 This is a top view of the present invention (before break-in).

[0024] Figure 7 This is a partial cross-sectional view of the assembly of the present invention (after break-in);

[0025] Figure 8 This is a top view of the invention (after break-in).

[0026] Figure 9 This is a comparison chart of the fan characteristics and static pressure efficiency of the present invention and conventional fans under different airflow rates;

[0027] Figure 10 for Figure 5 A magnified schematic diagram of a local convex rib.

[0028] Explanation of reference numerals in the attached drawings: 200-fan self-break-in structure; 210-fan frame; 212-annular flow channel; 2121-inner wall of the flow channel; 2122-groove; 220-fan wheel; 222-hub; 224-fan blade; 226-outer edge; 230-partial rib; 231-turning angle of attack; G-clearance. Detailed Implementation

[0029] Please see Figure 4 , Figure 5 and Figure 6As shown, the present invention provides a fan self-break-in structure 200, including a fan frame 210 and a fan wheel 220 disposed inside the fan frame 210. An annular flow channel 212 is formed inside the fan frame 210 to accommodate and rotate the fan wheel 220. The annular flow channel 212 has an air inlet and an air outlet at its two ends. An inner wall 2121 is provided within the flow channel to guide the airflow generated by the rotation of the fan wheel 220. The inner wall 2121 is initially a smooth surface without other structural features. The fan wheel 220 includes a hub 222 and a plurality of fan blades 224 extending from the periphery of the hub 222. Each fan blade 224 has an outer edge 226.

[0030] Each outer edge 226 has an outer diameter that is substantially equal to the inner diameter of the annular flow channel 212, and is provided with at least one local rib 230. This local rib 230 is formed by radially protruding outward from a local location on the outer edge 226 of the fan blade 224, and its outer diameter is slightly larger than the inner diameter of the annular flow channel 212. With this configuration, when the fan wheel 220 is assembled to the fan frame 210, the local rib 230 directly forms local interference contact with the inner wall 2121 of the annular flow channel 212.

[0031] The local rib 230 initially supports the surface of the inner wall 2121 of the flow channel, forming actual physical contact. Since the outer diameter of the local rib 230 is slightly larger than the outer edge 226 of its adjacent fan blade, it provides a specific support point before rotation begins. This interference support relationship will significantly reduce the local radial clearance G between the outer edge 226 of the fan blade 224 and the inner wall 2121 of the flow channel, thereby establishing a stable contact interface before break-in and providing a physical reference surface for wear between the local rib 230 and the inner wall 2121 of the flow channel during subsequent operation.

[0032] Furthermore, each fan blade 224 has local ribs 230 on its outer edge 226 in certain sections, and these ribs are distributed and spaced apart, rather than continuously interfering with the entire circumference. This design prevents overall frictional resistance, thus avoiding excessive starting resistance. At the same time, during rotation, only local areas make wear contact with the inner wall 2121 of the flow channel, gradually forming grooves at corresponding positions to establish a subsequent zero-clearance fit.

[0033] Please see Figure 7 , Figure 8The diagram shows the fan self-break-in structure 200 of the present invention after a period of initial operation. As the fan wheel 220 continues to rotate, the local ribs 230, which originally interfered with the inner wall 2121 of the flow channel, actively scrape the inner wall 2121 at their interference contact positions, thereby gradually forming a groove 2122 corresponding to its shape at the corresponding position. After break-in, the local ribs 230 can form a zero-gap or concave-convex corresponding fit with the groove 2122, and no longer interfere with the inner wall 2121 of the flow channel. Through this fit, the outer edge 226 of the adjacent fan blades 224 can be further brought closer to the inner wall 2121 of the flow channel, significantly reducing the local radial gap G between them to near zero.

[0034] The partial ribs 230 originally provided on the outer edge 226 of the fan blade 224 are now adapted to the grooves 2122 formed in the inner wall 2121 of the flow channel, allowing the outer edge 226 of the fan blade 224 in the adjacent section of the partial ribs 230 to be closer to the inner wall 2121 of the flow channel. This structural relationship results in a near-zero gap between the outer edge 226 and the inner wall 2121 of the flow channel, thereby establishing a closed airflow guiding interface. This effectively suppresses airflow from below the fan blade 224 through the gap to above the fan blade 224, reducing gap vortex phenomena and improving the static pressure efficiency and noise reduction performance of the fan. In one possible implementation, the radial protrusion of the local rib 230 is about 1 to 3 mm, and after running-in, it is embedded in the groove 2122 of the corresponding inner wall 2121 of the flow channel, thereby causing the gap G between the outer edge 226 of the remaining section of the fan blade 224 and the inner wall 2121 of the flow channel to converge to less than 0.2 mm or smaller, achieving a close fit, so as to form the aforementioned configuration that approaches zero gap.

[0035] Since the aforementioned local ribs 230 are fitted into the formed grooves 2122, and promote a near-zero gap fit between the outer edge 226 of the fan blade 224 and the inner wall 2121 of the flow channel, the airflow can flow smoothly along the guiding direction (i.e., axial direction) of the fan blade 224 when the fan is running. This airflow is blocked by the closed guiding structure formed by the outer edge 226 and the inner wall 2121 of the flow channel, effectively preventing the airflow from flipping from below to above the fan blade 224. This structure significantly suppresses the gap vortex and cyclone turbulence phenomena formed by radial gaps around the fan blades in conventional fans, and avoids pressure disturbances above the fan blades caused by airflow flipping, thereby stabilizing the airflow distribution inside the fan frame.

[0036] Please see Figure 9The figure shows a comparison of the fan characteristic curves and static pressure efficiency of the self-break-in structure 200 of this invention and a conventional fan under different airflow conditions. In this figure, the horizontal axis represents airflow, the vertical axis represents static pressure, curve A0 represents the fan characteristic curve of this invention, and curve B0 represents the conventional fan characteristic curve. It is clearly visible that within the airflow workload range, the fan pressure of this invention is higher than that of the conventional fan, demonstrating better performance. Furthermore, curve A1 represents the static pressure efficiency curve of the fan of this invention, and curve B1 represents the static pressure efficiency of the conventional fan. It is clearly visible that within the airflow workload range, the static pressure efficiency of the fan of this invention is significantly better than that of the conventional design, its maximum efficiency is significantly higher than that of the conventional fan, and the efficiency curve is smoother and more stable overall, indicating better performance within the working airflow range. This technical feature not only improves static pressure output and airflow concentration but also helps reduce high-frequency wind shear noise and resonance, achieving a dual improvement in both air pressure and noise efficiency.

[0037] Please see Figure 10 As shown, Figure 5 A partially enlarged schematic diagram of the local protruding rib 230. As shown in the figure, the local protruding rib 230 may have an inclined surface or chamfer structure at its front end (i.e., the windward end) in the rotation direction of the fan wheel 220, forming a turning angle 231. This turning angle 231 has both guiding and cutting properties, which facilitates rapid guiding and scraping of the inner wall 2121 of the flow channel during initial rotation.

[0038] Furthermore, the setting of the turning angle 231 can improve the initial contact efficiency between the local protrusion 230 and the inner wall 2121 of the flow channel, allowing for smooth local scraping during the initial break-in period, reducing rotational resistance, and thus smoothly and quickly forming the groove 2122 profile that matches the local protrusion 230, improving the fitting accuracy and efficiency. This design can also prevent the end of the local protrusion 230 from being damaged by hard impact, which helps to improve the stability and feasibility of the break-in process.

[0039] In summary, the self-break-in structure 200 of the present invention provides a local rib 230 on the outer edge 226 of the fan blade 224, and establishes an initial interference contact relationship between the local rib 230 and the inner wall 2121 of the flow channel of the fan frame 210. During the rotation of the fan wheel 220, the local rib 230 actively scrapes the inner wall 2121 of the flow channel to form a groove 2122, thereby forming a zero-gap or corresponding concave-convex movable close fit after the break-in is completed. This design allows the outer edge 226 of the fan blade to approach the inner wall 2121 of the flow channel, forming a nearly closed airflow guiding interface, which effectively suppresses airflow turbulence, gap eddies and resonance phenomena, thereby improving the static pressure efficiency and noise reduction effect of the fan during operation. Furthermore, by setting a turning angle of attack 231 at the front end of the local rib 230, the contact introduction efficiency and scraping stability in the early stage of break-in can be improved, achieving highly controllable and precise self-break-in behavior. This is an innovative fan structure design with self-adjusting fit effect, high manufacturing tolerance and no increase in processing cost.

[0040] The above description is a detailed account of the preferred embodiments of the present invention. Any equivalent or similar modifications made based on the teachings disclosed in the present invention should naturally be included within the protection scope of the present invention.

Claims

1. A fan self-break-in structure, characterized in that, include: A frame having an annular flow channel with an inner wall; A fan wheel is disposed within the annular flow channel and is rotatable relative to the fan frame. The fan wheel has a plurality of fan blades, and each fan blade has at least one radially protruding partial rib at one outer end edge. The outer diameter of the at least one partial rib is substantially larger than the inner diameter of the annular flow channel so as to form partial interference with the inner wall of the flow channel. During the initial operation of the fan wheel, the local ribs make local contact wear with the inner wall of the flow channel, forming at least one groove at the corresponding position on the inner wall of the flow channel. After the local ribs and the grooves are worn together, they can form a zero gap or a concave-convex corresponding fit. This reduces the local gap between the outer edge of the fan blade and the inner wall of the flow channel, creating a near-zero gap configuration to suppress airflow from below the fan blade to above, thereby reducing gap vortices and lowering operating noise.

2. The fan self-break-in structure as described in claim 1, characterized in that: The local rib has a turning angle at one front end in the direction of rotation of the fan wheel, so as to scrape it when it first comes into contact with the inner wall of the flow channel.

3. The fan self-break-in structure as described in claim 2, characterized in that: The cutting angle of attack of the machine is an inclined surface or a chamfered structure.

4. The fan self-break-in structure as described in claim 1, characterized in that: The outer diameter of the outer edge of the fan blade is essentially equal to the inner diameter of the annular flow channel.

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