Cooling fan

Abstract

The invention belongs to the technical field of cooling fans, and discloses a cooling fan. The cooling fan comprises a hub, a first ring, first blades and second blades, the first blades are connected between the hub and the first ring, the second blades are connected to the side, away from the hub, of the first ring, the bending degree of the first blades is smaller than that of the second blades, and the first blades and the second blades have different installation angles. The blade tip chord length of the first blade is equal to the blade root pitch of the second blade, and the tail edge of the first blade and the tail edge of the second blade are arranged in an aligned mode. Different mounting angles can reduce order noise in the rotating process, the overall ventilation performance can be improved through the large bending and sweeping degree of the second blades, the flow and flow field uniformity can be ensured through the alignment arrangement mode, airflow is kept to flow in one direction, meanwhile, channel vortexes at the second blades are prevented from being directly drawn into the first blades, and the ventilation effect is improved. The disturbance of the wake of the first blade to the downstream is reduced, and the multiple effects of improving aerodynamic efficiency and stability and reducing noise are achieved.

Description

Technical Field

[0001] This invention relates to the field of cooling fan technology, and more particularly to a cooling fan. Background Technology

[0002] Cooling fans are an important component of automotive air conditioning systems, accelerating heat exchange between the air conditioner and the air, thereby improving cooling efficiency.

[0003] However, as the requirements for cooling and heat exchange efficiency increase, the requirements for airflow velocity also increase, leading to a corresponding increase in the required speed of the cooling fan. While the cooling fan is working at high speed, it also generates more noise, resulting in a higher level of noise in the cockpit and reducing the user's driving experience.

[0004] Therefore, there is an urgent need for a cooling fan to solve the above-mentioned technical problems. Summary of the Invention

[0005] The purpose of this invention is to provide a cooling fan that can reduce noise, especially lower the order noise level, while ensuring heat exchange efficiency.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] Cooling fans, including:

[0008] A hub and a first ring, wherein the hub and the first ring are coaxially arranged;

[0009] A first blade, a plurality of first blades connected between the hub and the first ring, and the first blades having different mounting angles;

[0010] Second blades, multiple second blades are connected to the side of the first ring away from the hub, the sweep angle of the first blades is smaller than that of the second blades, and the second blades have different mounting angles;

[0011] The tip chord length of the first blade and the root pitch of the second blade are equal, and the trailing edges of the first blade and the second blade are aligned.

[0012] In some embodiments, each of the first blades includes an upper blade and a lower blade, wherein the leading edge of the lower blade is disposed corresponding to and spaced apart from the trailing edge of the upper blade.

[0013] In some embodiments, along the circumferential direction of the hub, there is a preset circumferential distance L1 between the leading edge of the lower blade and the trailing edge of the upper blade, wherein the preset circumferential distance L1 is 2-5 mm; and,

[0014] Along the axial direction of the hub, there is a preset axial distance L2 between the leading edge of the lower blade and the trailing edge of the upper blade, and the preset axial distance L2 is 2-5mm.

[0015] In some embodiments, a central slit is defined between the upper blade and the lower blade of each first blade, the chord length of the central slit being 0.5-1.5 mm.

[0016] In some embodiments, the mounting angle of the upper blade and the mounting angle of the lower blade in each of the first blades have an angular difference of 0.5-1°.

[0017] In some embodiments, the cooling fan has 11 first blades and 11 second blades, and the installation angle of the first blades and the second blades is 32-34°; or,

[0018] The cooling fan has 13 first blades and 13 second blades, and the installation angle of the first blades and the second blades is 27-29°; or,

[0019] The cooling fan has 15 first blades and 15 second blades, and the installation angle of the first blades and the second blades is 23-25°; or,

[0020] The cooling fan has 17 first blades and 17 second blades, and the installation angle of the first blades and the second blades is 21-22°; or,

[0021] The cooling fan has 19 first blades and 19 second blades, and the mounting angle of the first blades and the second blades is 18-19°.

[0022] In some embodiments, the second blade has a forward tilt angle of 0° at the leaf root, a forward tilt angle of -2° at 20% of its spread, a forward tilt angle of 0° at 40% of its spread, and a forward tilt angle of 20° at the leaf tip.

[0023] In some embodiments, the cooling fan further includes a second ring, wherein the root of the second blade is connected to the first ring, and the tip of the second blade is connected to the second ring.

[0024] In some embodiments, the diameter of the second ring is 350mm-500mm, and the span of the first blade accounts for 25%-75% of the sum of the spans of the first blade and the second blade.

[0025] In some embodiments, the diameter of the cooling fan is greater than 500 mm, and the cooling fan includes at least a third blade, a second ring, and a third ring. The second blade is connected between the first ring and the second ring, and the third blade is connected between the second ring and the third ring. Adjacent third blades have different mounting angles.

[0026] The above technical solution has the following advantages or beneficial effects:

[0027] Setting the first and second blades at different installation angles reduces order noise during rotation. The larger sweep angle of the second blade improves ventilation performance, while the aligned arrangement ensures uniformity of flow rate and flow field, maintains unidirectional airflow, and prevents the channel vortex at the second blade from being directly drawn into the first blade, reducing the disturbance of the first blade's wake to the downstream. This achieves multiple effects, including improving aerodynamic efficiency and stability and reducing noise. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of a fan blade in existing related technologies;

[0029] Figure 2 This is a three-dimensional structural diagram of the cooling fan in an embodiment of the present invention;

[0030] Figure 3 This is a front view structural diagram of the cooling fan in an embodiment of the present invention;

[0031] Figure 4 This is a cross-sectional view of the cooling fan in an embodiment of the present invention;

[0032] Figure 5 This is a three-dimensional structural diagram of the first blade in an embodiment of the present invention.

[0033] In the picture:

[0034] 1. Wheel hub;

[0035] 2. First blade; 20. Center slit; 21. Upper blade; 22. Lower blade;

[0036] 3. First ring;

[0037] 4. Second blade;

[0038] 5. The second ring. Detailed Implementation

[0039] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0040] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," "fixed," and "abutting" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to 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 invention based on the specific circumstances.

[0041] 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.

[0042] In the description of this embodiment, the terms "upper," "lower," "right," and "left," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, 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 the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0043] like Figure 1 As shown, the fan blades used in related technologies include a hub, axial blades, and an outer ring. The hub is connected to the drive motor, the outer ring is coaxially mounted with the hub, and the axial blades are fixedly connected between the hub and the outer ring. The number of axial blades is generally 5-11, and they all have the same installation angle, thus generating significant order noise.

[0044] like Figures 2 to 5As shown, to alleviate order noise, this invention provides a cooling fan. The cooling fan includes a hub 1, a first ring 3, a first blade 2, and a second blade 4. The hub 1 and the first ring 3 are coaxially arranged. The first blade 2 is connected between the outer circumferential surface of the hub 1 and the inner circumferential surface of the first ring 3, while the second blade 4 is connected to the outer circumferential surface of the first ring 3 (i.e., the surface of the first ring 3 away from the hub 1). The first blade 2 has a different mounting angle, and the second blade 4 also has a different mounting angle, thereby reducing order noise during rotation. The second blade 4 has a larger sweep angle than the first blade 2, exhibiting a forward-swept blade design, which increases the airflow of the cooling fan at 0 Pa and improves its ventilation performance.

[0045] And, as Figure 3 As shown, the tip chord length of the first blade 2 and the root pitch of the second blade 4 are equal, and the trailing edges of the first blade 2 and the second blade 4 are aligned. This arrangement ensures that the chord lengths of the first blade 2 and the second blade 4 are maintained at the same position on the flow channel surface, allowing for a smooth transition of airflow at the first ring 3 and preventing flow separation and energy loss. Specifically, at the root of the second blade 4, due to its proximity to the first ring 3, the airflow forms a high-pressure, low-energy fluid due to friction, resulting in a slow flow velocity and low energy. At the tip of the first blade 2, the airflow is in a lower-pressure state due to centrifugal effect. If the first blade 2 and the second blade 4 are misaligned, the low-energy fluid outside the first ring 3 will impact the first blade 2, disrupting the airflow, increasing resistance, and reducing the flow rate. Therefore, by aligning the first blade 2 and the second blade 4 and blocking the airflow through the first ring 3, the uniformity of flow rate and flow field can be ensured, the airflow can be kept in one direction, and the channel vortex at the second blade 4 can be prevented from being directly drawn into the first blade 2, thus reducing the disturbance of the wake of the first blade 2 to the downstream and achieving multiple effects such as improving aerodynamic efficiency and stability and reducing noise.

[0046] Preferably, each cooling fan includes at least 11 first blades 2 and at least 11 second blades 4, thereby increasing the frequency and reducing order noise. Exemplarily, in some embodiments, the cooling fan has 11 first blades 2 and 11 second blades 4, and the mounting angles of the first blades 2 and second blades 4 are 32-34°. For example, the first blades 2 and second blades 4 are arranged sequentially with mounting angles of 32.78°, 33.07°, 32.39°, 32.86°, 32.88°, 32.38°, 33.06°, 32.60°, 32.57°, 33.08°, and 32.40°. In some other embodiments, the cooling fan has 13 first blades 2 and 13 second blades 4, and the mounting angles of the first blades 2 and second blades 4 are 27-29°. For example, the first blade 2 and the second blade 4 are arranged sequentially with mounting angles of 27.60°, 27.56°, 27.45°, 27.74°, 27.95°, 27.74°, 27.45°, 27.56°, 27.89°, 27.69°, 27.57°, 27.45°, and 28.05°. In some other embodiments, the cooling fan has 15 first blades 2 and 15 second blades 4, and the mounting angles of the first blades 2 and the second blades 4 are 23-25°. For example, the first blade 2 and the second blade 4 are arranged sequentially with mounting angles of 23.92°, 23.85°, 24.24°, 23.69°, 24.36°, 23.61°, 24.39°, 23.63°, 24.33°, 23.74°, 24.17°, 23.92°, 23.97°, 24.13°, and 23.86°. In some other embodiments, the cooling fan has 17 first blades 2 and 17 second blades 4, and the mounting angles of the first blades 2 and the second blades 4 are 21-22°. For example, the first blade 2 and the second blade 4 are arranged sequentially with mounting angles of 21.08°, 21.24°, 21.15°, 21.07°, 21.04°, 21.07°, 21.15°, 21.24°, 21.30°, 21.31°, 21.25°, 21.15°, 21.07°, 21.15°, and 21.24°. In some other embodiments, the cooling fan has 19 first blades 2 and 19 second blades 4, and the mounting angles of the first blades 2 and the second blades 4 are 18-19°. For example, the first blade 2 and the second blade 4 are both set with installation angles of 18.97°, 19.00°, 18.99°, 18.98°, 18.96°, 18.94°, 18.93°, 18.91°, 18.90°, 18.89°, 18.89°, 18.90°, 18.91°, 18.92°, 18.94°, 18.95°, 18.97°, and 18.99° respectively.

[0047] As can be seen from the above-listed embodiments, when the number of blades is small, any adjacent first blade 2 (or second blade 4) can adopt different mounting angles, achieving a better effect of reducing order noise. However, when the number of blades is large, adjacent first blades 2 (or second blades 4) are allowed to adopt the same mounting angle, thus facilitating manufacturing. Therefore, this invention does not limit whether adjacent blades have the same mounting angle, as long as there are significantly different mounting angles among all the first blades 2 (or second blades 4).

[0048] Furthermore, in this embodiment, the second blade 4 has a 0° forward tilt angle at its root (point A in the figure), a -2° forward tilt angle at 20% of its span (point B in the figure), a 0° forward tilt angle at 40% of its span (point C in the figure), and a 20° forward tilt angle at its tip (point D in the figure). By controlling the forward tilt angle of the second blade 4, a forward-swept blade with a large sweep angle can be formed, thereby increasing the flow rate and improving aerodynamic efficiency. Preferably, the cooling fan also includes a second ring 5, with the root of the second blade 4 connected to the first ring 3 and the tip of the second blade 4 connected to the second ring 5. The second ring 5 can reduce the flow loss caused by leakage flow at the tip of the second blade 4 driven by pressure difference, thereby further ensuring flow rate and aerodynamic efficiency.

[0049] Furthermore, in this embodiment, the diameter of the second ring 5 is 350mm-500mm, and the span of the first blade 2 accounts for 20%-80% of the sum of the spans of the first blade 2 and the second blade 4. When only the first blade 2, the second blade 4, the first ring 3, and the second ring 5 are included, since the deflection and pressurization capabilities of the first blade 2 are much smaller than those of the second blade 4, the greater the distance between the hub 1 and the first ring 3, the larger the proportion of the first blade 2 relative to the entire cooling fan, which is more conducive to weakening the separation vortex and the flow mixing phenomenon at the first ring 3, thereby significantly reducing the turbulent kinetic energy intensity on the blade surface and achieving the effect of reducing overall noise. As the proportion of the first blade 2 relative to the entire cooling fan decreases and the proportion of the second blade 4 relative to the entire cooling fan increases, it will lead to greater noise and increased airflow pressure, thereby increasing the flow rate. Optionally, the diameter of the hub 1 is 150-180mm to avoid excessive encroachment on the sum of the spans of the first blade 2 and the second blade 4. The span of the first blade 2 accounts for 25% or 75% of the sum of the spans of the first blade 2 and the second blade 4, and the span of the second blade 4 accounts for 75% or 25% of the sum of the spans of the first blade 2 and the second blade 4.

[0050] Understandably, as the overall diameter of the cooling fan increases, structures such as a third blade and a third ring can be added to achieve a multi-segment blade structure, which can also reduce noise and improve efficiency. For example, when the diameter of the cooling fan is 420mm or more, a third blade can be connected to the outer circumference of the second ring 5, and a third ring can be set at the tip of the third blade. When the diameter of the cooling fan is further increased to 500mm or more, a fourth blade can be set on the outer circumference of the third ring, and a fourth ring can be set at the tip of the fourth blade. When the diameter of the cooling fan is further increased to 600mm or more, a fifth blade can be set on the outer circumference of the fourth ring, and a fifth ring can be set at the tip of the fifth blade. Of course, to achieve the effect of reducing order noise, adjacent third blades and adjacent fourth blades also have different mounting angles.

[0051] Correspondingly, when a third blade and a third ring are provided, compared to the sum of the spans of the first blade 2, the second blade 4, and the third blade, the span of the first blade 2 is 20%-40%, the span of the second blade 4 is 20%-40%, and the span of the third blade is also 20%-40%. For example, the span of the first blade 2 is 20%, and the spans of the second blade 4 and the third blade are both 40%. When a fourth blade is further provided, the span percentages of the first blade 2, the second blade 4, the third blade, and the fourth blade can be 20%, 20%, 20%, and 40%, or 20%, 20%, 40%, and 20%, or 40%, 20%, 20%, and 20%. Similarly, when a fifth blade is further provided, the span ratio of the first blade 2, the second blade 4, the third blade, the fourth blade, and the fifth blade can be 15%, 15%, 15%, 15%, 40%, or 15%, 15%, 15%, 40%, 15%, or 15%, 15%, 40%, 15%, 15%, or 15%, 40%, 15%, 15%, 15%, or 40%, 15%, 15%, 15%, 15%.

[0052] Therefore, this invention does not specifically limit whether or not a third blade or other structures are provided. As long as the first blade 2, the first ring 3 and the second blade 4 mentioned above are provided, they fall within the scope of protection of this invention.

[0053] Furthermore, in this embodiment, each first blade 2 includes an upper blade 21 and a lower blade 22, with the leading edge of the lower blade 22 corresponding to and spaced apart from the trailing edge of the upper blade 21. A central slit 20 is formed between the upper blade 21 and the lower blade 22. Through the central slit 20, high-energy fluid can be injected into the boundary layer of the suction surface like a jet, thereby reducing the impact of the suction surface split flow on the flow field uniformity, outlet pressure, and impeller efficiency.

[0054] For example, in this embodiment, the chord length of the central slit 20 is 0.5-1.5 mm, thereby constraining the flow rate of the high-energy fluid. Specifically, in this embodiment, along the circumferential direction of the hub 1, there is a preset circumferential distance L1 between the leading edge of the lower blade 22 and the trailing edge of the upper blade 21, the preset circumferential distance L1 being 2-5 mm. Simultaneously, along the axial direction of the hub 1, there is a preset axial distance L2 between the leading edge of the lower blade 22 and the trailing edge of the upper blade 21, the preset axial distance L2 being 2-5 mm.

[0055] It should be noted that the mounting angle of the first blade 2 can be either the mounting angle of the upper blade 21 or the mounting angle of the lower blade 22. Furthermore, in order to reduce order noise, the mounting angles of the upper blade 21 and the lower blade 22 in each first blade 2 have an angle difference of 0.5-1°.

[0056] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0057] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A cooling fan, characterized in that, include: A hub (1) and a first ring (3) are coaxially arranged; First blade (2), multiple first blades (2) are connected between the hub (1) and the first ring (3), and the first blades (2) have different mounting angles; Second blade (4), multiple second blades (4) are connected to the first ring (3) on the side away from the hub (1), the sweep angle of the first blade (2) is smaller than that of the second blade (4), and the second blade (4) has different mounting angles; The tip chord length of the first blade (2) and the root pitch of the second blade (4) are equal, and the trailing edge of the first blade (2) and the trailing edge of the second blade (4) are aligned.

2. The cooling fan according to claim 1, characterized in that, Each of the first blades (2) includes an upper blade (21) and a lower blade (22), the leading edge of the lower blade (22) being disposed corresponding to and spaced apart from the trailing edge of the upper blade (21).

3. The cooling fan according to claim 2, characterized in that, Along the circumferential direction of the hub (1), there is a preset circumferential distance L1 between the leading edge of the lower blade (22) and the trailing edge of the upper blade (21), the preset circumferential distance L1 being 2-5 mm; and, Along the axial direction of the hub (1), there is a preset axial distance L2 between the leading edge of the lower blade (22) and the trailing edge of the upper blade (21), the preset axial distance L2 being 2-5mm.

4. The cooling fan according to claim 3, characterized in that, A central slit (20) is defined between the upper blade (21) and the lower blade (22) of each first blade (2), the chord length of the central slit (20) being 0.5-1.5 mm.

5. The cooling fan according to claim 2, characterized in that, The mounting angle of the upper blade (21) and the mounting angle of the lower blade (22) in each of the first blades (2) have an angle difference of 0.5-1°.

6. The cooling fan according to claim 5, characterized in that, The cooling fan has 11 first blades (2) and 11 second blades (4), and the mounting angles of the first blades (2) and the second blades (4) are 32-34°; or, The cooling fan has 13 first blades (2) and 13 second blades (4), and the mounting angles of the first blades (2) and the second blades (4) are 27-29°; or, The cooling fan has 15 first blades (2) and 15 second blades (4), and the mounting angles of the first blades (2) and the second blades (4) are 23-25°; or, The cooling fan has 17 first blades (2) and 17 second blades (4), and the mounting angles of the first blades (2) and the second blades (4) are 21-22°; or, The cooling fan has 19 first blades (2) and 19 second blades (4), and the mounting angle of the first blades (2) and the second blades (4) is 18-19°.

7. The cooling fan according to claim 6, characterized in that, The second leaf (4) has a forward tilt angle of 0° at the leaf root, a forward tilt angle of -2° at 20% of the spread of the second leaf (4), a forward tilt angle of 0° at 40% of the spread of the second leaf (4), and a forward tilt angle of 20° at the leaf tip of the second leaf (4).

8. The cooling fan according to claim 6, characterized in that, The cooling fan also includes a second ring (5), the root of the second blade (4) is connected to the first ring (3), and the tip of the second blade (4) is connected to the second ring (5).

9. The cooling fan according to claim 8, characterized in that, The diameter of the second ring (5) is 350mm-500mm. The span of the first blade (2) is 25%-75% of the sum of the spans of the first blade (2) and the second blade (4).

10. The cooling fan according to claim 8, characterized in that, The diameter of the cooling fan is greater than 500mm. The cooling fan includes at least a third blade and a third ring. The second blade (4) is connected between the first ring (3) and the second ring (5). The third blade is connected between the second ring (5) and the third ring. Adjacent third blades have different mounting angles.

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