Noise reduction profiled blade structure of an axial fan

Abstract

This utility model relates to a noise-reducing irregular blade structure for an axial flow fan, addressing the technical problem of high noise at the blades of existing similar products, resulting in poor heat dissipation and low airflow, particularly the difficulty in using the pterosaur structure of the blades in overlapping blade configurations. The key features are that the fan blades are equidistantly arranged on the outer diameter of the hub, overlapping vertically, with irregularly shaped wings curving upwards towards the bottom edge. These irregularly shaped wings are positioned at the midpoint of the end chord length of the side edge, with lengths ranging from 70% to 80% of the total length. The curvature of the irregularly shaped wings increases obliquely in an arc from one side of the top opening of the hub to the other side, with the height h at the increased end being less than 4mm, extending parallel to the other end in an arc shape. The angle α between the fan blade and the irregularly shaped wing along the midline of the fan blade is acute, and the shape of the irregularly shaped wing at the end of the fan blade resembles a dolphin's wing.

Description

Technical Field

[0001] This utility model relates to the blades of a cooling fan, specifically a noise-reducing irregular blade structure for an axial flow fan. Background Technology

[0002] Cooling fans generally refer to fans used to cool motherboard devices such as CPUs and graphics cards. Some cooling fans also have heat sinks. Their main purpose is to conduct heat away and blow it into the surrounding air to achieve a cooling effect. Simultaneously, with the increasingly widespread application of electronic products and the increasingly sophisticated equipment installed in them, cooling fans are gradually being widely used in metal cabinets for servers and other equipment. Some existing fans have fan blades with raised edges, such as application number 202322743231.9 disclosed in Chinese patent literature, authorized on June 4, 2024, with the utility model title "Cooling Fan"; and application number 202023141270.4 disclosed in Chinese patent literature, authorized on October 15, 2021, with the utility model title "New High-Performance Low-Noise Cooling Fan". The aforementioned products and similar products have small, upturned winglets at the tips of the blades, called winglets, or pterodactyls in the industry. When airflow passes over the upper and lower surfaces of the blades, a pressure difference is created. The high-pressure area on the lower surface of the blade then flows around the wingtip to the upper surface, forming a strong vortex. This wingtip vortex carries a large amount of energy and is dragged behind the wingtip, creating a noise source. However, the pterodactyls in these products and similar products can generally only be applied to non-overlapping blade profiles because when the blade tip is bent, the mold can only be used for vertical ejection; overlapping blades cannot be molded vertically. Summary of the Invention

[0003] To overcome the aforementioned shortcomings, the purpose of this utility model is to provide a noise-reducing irregular blade structure for axial flow fans, thereby solving the technical problems of high noise at the blades of existing similar products, resulting in poor heat dissipation and low airflow, and particularly the difficulty in using the pterosaur structure of the blades in overlapping blade configurations. This objective is achieved through the following technical solution.

[0004] A noise-reducing irregular blade structure for an axial flow fan is disclosed. The fan body includes blades and a hub. The blades are equidistantly positioned on the outer diameter of the hub and overlap vertically. The edges of the blades have irregularly shaped wings that curve upwards towards the bottom. The key design feature is that the irregularly shaped wings on the blades are positioned at the midpoint of the end chord length of the side edges, with lengths ranging from 70% to 80% of the total length. The upward curve of the irregularly shaped wings increases obliquely from one side of the top opening of the hub towards the other side, with the height h at the increased end being less than 4mm. Thus, the irregularly shaped wings at the ends of the blades resemble dolphin-like small wings. This dolphin wing design is a further development of the pterosaur structure, solving the problem of overlapping blades being unsuitable for pterosaur applications. The dolphin wing, distributed in the middle of the end chord length, does not interfere with the movement of the lateral slider at the hub.

[0005] The irregularly shaped wings at the fan blades of the fan body are oblique arcs with an angle greater than 5 degrees and less than 10 degrees. After increasing to the height of the end, they extend parallel to the other end and bend in an arc shape.

[0006] The included angle between the two ends of the irregular wing at the fan blade of the fan body is 65 degrees.

[0007] The angle α between the fan blade and the irregularly shaped airfoil along the center line of the fan blade is an acute angle. This structure differs from the obtuse angle structure design of existing similar products, resulting in better noise reduction.

[0008] The hub of the fan body has a through hole in the middle of its bottom. The outer diameter of the through hole has a tapered rib protruding towards the bottom, and the inner diameter of the through hole has a stepped groove for inserting the rear of the shaft core. The outer side of the rib has equidistant first balance grooves on the bottom circumferential surface of the hub. The above describes the balance adjustment structure design at the rear of the hub, as well as the design of the cover and shaft core assembly structure.

[0009] The hub top opening of the fan body has a second balance groove that is equidistantly spaced and opens inward. The above describes the balance adjustment structure design at the opening at the front of the hub.

[0010] This utility model has a reasonable structural design, good heat dissipation effect, and wide application range. In particular, the dolphin wing reduces tip vortex, thereby reducing noise and solving the problem that overlapping blades cannot use small winglets. The dolphin wing has low noise and high airflow. It is suitable for use as a noise reduction irregular blade structure for axial fans and for further improvement of similar products. Attached Figure Description

[0011] Figure 1 This is a side view structural diagram of an embodiment of the present invention.

[0012] Figure 2 yes Figure 1 A top-view structural diagram.

[0013] Figure 3 yes Figure 1 A schematic diagram of the three-dimensional structure.

[0014] Figure 4 yes Figure 3 A schematic diagram of the internal structure of the bottom wheel hub.

[0015] Figure 5 yes Figure 3 A cross-sectional structural diagram.

[0016] Figure 6 This is a comparison curve of noise data between an embodiment of this utility model and an existing conventional wing fan.

[0017] The attached figures are numbered and named as follows: 1. Fan body, 101. Fan blade, 102. Hub, 103. Irregular wing, 104. Perforated rib, 105. Step groove, 106. First balance groove, 107. Second balance groove. Implementation

[0018] The structure and use of this utility model will now be further described with reference to the accompanying drawings. Figures 1-6 As shown, the fan body 1 of this structure includes fan blades 101 and a hub 102. The fan blades are equidistantly arranged on the outer diameter of the hub and are arranged in an overlapping manner. The edges of the fan blades are provided with irregularly shaped wings 103 that curve upwards to the bottom side. The irregularly shaped wings at the fan blades are respectively set at the middle of the end chord length of the side edge, and their lengths are 70% to 80% of the length. The upward height of the irregularly shaped wings increases obliquely in an arc shape from the top opening side of the hub to the bottom side, and the height h of the end of the increased side is less than 4mm. Specifically, the irregularly shaped wings at the fan blades of the above-mentioned fan body are obliquely arc-shaped with an angle greater than 5 degrees and less than 10 degrees, which increases to the height of the end and then extends parallel to the other end in an arc shape. The angle between the two ends of the irregularly shaped wings at the fan blades of the fan body is 65 degrees. The angle α between the fan blades and the irregularly shaped wings along the midline of the fan blades is an acute angle.

[0019] Meanwhile, the hub of the aforementioned fan body has a through hole in the middle, and the outer diameter of the through hole has a tapered rib 104 that protrudes to the bottom. The inner diameter of the through hole has a stepped groove 105 for the rear of the shaft core to be inserted. The bottom circumferential surface of the hub outside the rib has a first balance groove 106 that is equidistantly arranged. The inner diameter of the top hole of the fan body hub has a second balance groove 107 that is equidistantly arranged and opens inward.

[0020] During assembly, the shaft core is inserted through the bottom of the fan body's hub, and the integrated disc at the end of the shaft core is positioned and fixed in the stepped groove of the hub. Next, the motor housing is installed inside the fan body's hub, and a magnet is installed on the inner wall of the motor housing. Then, the motor assembly with a central tube, circuit board, silicon steel sheet, and winding is installed, and the shaft core is inserted into the central tube of the motor assembly. Finally, the balance of the fan body's rotation is adjusted through the first and second balance grooves, and the first balance groove at the bottom of the hub is sealed. The cooling fan with this structure is then assembled.

Claims

1. A noise-reducing irregular blade structure for an axial flow fan, wherein the fan body (1) comprises fan blades (101) and a hub (102), the fan blades being equidistantly arranged on the outer diameter of the hub and overlapping vertically, and the edges of the fan blades having irregularly shaped wings (103) that curve upwards to the bottom; characterized in that The irregular wings (103) at the fan blades (101) of the fan body (1) are respectively set at the middle of the end chord length of the side edge, and their lengths are 70% to 80% of the length respectively; the raised height of the irregular wings increases obliquely in an arc shape from one side of the top opening of the hub (102) to the other side of the bottom, and the height h of the increased side end is less than 4mm.

2. The noise-reducing irregular blade structure of the axial flow fan according to claim 1, characterized in that... The irregular wings (103) at the fan blades (101) of the fan body (1) are respectively oblique arcs with an angle greater than 5 degrees and less than 10 degrees. After increasing to the height of the end, they extend parallel to the other end and bend in an arc shape.

3. The noise-reducing irregular blade structure of the axial flow fan according to claim 2, characterized in that... The included angle between the two ends of the irregular wing (103) at the fan blade (101) of the fan body (1) is 65 degrees.

4. The noise-reducing irregular blade structure of the axial flow fan according to claim 1, characterized in that... The angle α between the fan blade (101) and the shaped wing (103) along the midline of the fan blade is an acute angle.

5. The noise-reducing irregular blade structure of the axial flow fan according to claim 1, characterized in that... The hub (102) of the fan body (1) has a through hole in the middle of its bottom. The outer diameter of the through hole has a tapered rib (104) that protrudes towards the bottom. The inner diameter of the through hole has a stepped groove (105) for the rear of the shaft core to be inserted. The bottom circumferential surface of the hub outside the rib has a first balance groove (106) that is equidistantly arranged.

6. The noise-reducing irregular blade structure of the axial flow fan according to claim 1, characterized in that... The hub (102) of the fan body (1) has a second balance groove (107) that is equidistantly arranged and opens inward on the inner diameter of the top opening.

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