A fan assembly

Abstract

The application discloses a fan blade assembly, which comprises a hub for connecting with a fan rotating shaft and a silencing ring formed by an annular plastic member. A plurality of fan blades are arranged in a circumferential direction along the periphery of the hub, the fan blades comprising first fan blades and second fan blades arranged alternately in the circumferential direction, and the radial length L1 of the first fan blades is greater than the radial length L2 of the second fan blades. Each fan blade is rigidly connected with the silencing ring at a radial middle region of the fan blade, so that the silencing ring and all the fan blades form an integral support structure, wherein the radial position of the silencing ring on the first fan blades is located in the range of 0.8L1-0.9L1 away from the blade root, and the radial position of the silencing ring on the second fan blades is located in the range of 0.3L2-0.7L2 away from the blade root. By alternately arranging the long and short fan blades and respectively optimizing the support positions of the silencing ring, the main flexure regions of the fan blades with different lengths can be effectively constrained, the deformation and vibration of the fan blades during high-speed operation can be reduced, the operation noise can be reduced, and the structural stability and silencing performance of the fan blade assembly can be improved.

Description

Technical Field

[0001] This invention belongs to the technical field of fans and ventilation equipment, specifically relating to a metal-plastic hybrid fan blade assembly with a central plastic noise-reducing ring. Background Technology

[0002] Most fan blades in existing electronic devices use a single material structure, such as all-metal blades or all-plastic blades. Metal blades have high strength and rigidity, making them suitable for high-volume, high-speed operation. However, the metal material is relatively heavy, and under the combined action of centrifugal force and aerodynamic force, the fan blades are prone to vibration and noise. Long-term operation may also lead to fatigue cracking. Plastic blades are lighter, easier to mold, and lower in cost, and have a certain damping effect. However, their overall strength and fatigue resistance are limited, and they are prone to large deformation under high-speed or large-diameter conditions, affecting aerodynamic performance and service life.

[0003] To improve the overall stiffness and stability of fan blades, some existing technologies incorporate reinforcing or connecting rings near the hub or blade tip to constrain and support the blades. However, these reinforcing rings are mostly metal structures, primarily serving to increase stiffness, but offering limited suppression of vibration and noise, and may even exacerbate resonance noise due to excessive rigidity. Furthermore, the placement of the reinforcing rings does not perfectly align with areas where blade deformation is concentrated, resulting in poor control over blade deflection in the radial center.

[0004] In addition, existing technologies also include solutions that combine metal blades with plastic components, such as adding plastic edging to the blade edges or adding plastic connectors at the blade root to improve assemblability or reduce local noise. However, these solutions mostly focus on improving local structures and do not systematically optimize the overall mechanical distribution and vibration characteristics of the fan blades. Under long-term, high-speed operation of the fan, the fan blades may still experience problems such as large deformation, high noise, and significant fatigue damage.

[0005] In summary, existing fan blade assemblies still have shortcomings in balancing high strength, low noise, and long lifespan, especially in deformation control, vibration suppression, and connection reliability in the radial mid-region of the fan blade, which require further improvement. Therefore, how to provide a fan blade assembly with a reasonable structure, optimized material combination, and the ability to effectively limit fan blade deformation and reduce operating noise has become a technical problem that needs to be solved by those skilled in the art. Summary of the Invention

[0006] This invention aims to solve the technical problems of existing fan blades, such as excessive noise and vibration during high-speed operation, and insufficient structural stability. To this end, this invention provides a fan blade assembly that is structurally robust, exhibits excellent noise reduction, and demonstrates good aerodynamic performance.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A fan blade assembly includes a hub, a noise reduction ring, and a plurality of fan blades. The hub is used to connect to a fan shaft. The plurality of fan blades are arranged circumferentially at intervals along the periphery of the hub, and the fan blades include first fan blades and second fan blades that are alternately arranged circumferentially, wherein the radial length of the first fan blade is greater than the radial length of the second fan blade.

[0008] The silencing ring is made of a ring-shaped plastic component. Each fan blade is rigidly connected to the silencing ring in its radial center region, forming an integral support structure with all fan blades.

[0009] The connection positions of the silencing ring and the fan blades of different lengths are specifically designed to meet the following requirements: The radial position of the silencing ring on the first fan blade is within the range of 0.8L1 to 0.9L1 from the blade root of the first fan blade; The radial position of the silencing ring on the second fan blade is within the range of 0.3L2 to 0.7L2 from the blade root of the second fan blade; Wherein, L1 is the radial length of the first fan blade, and L2 is the radial length of the second fan blade.

[0010] As a further improvement of the present invention, the main body of the fan blade is a metal blade body, preferably formed by stamping aluminum alloy or stainless steel sheet, so as to ensure the strength and durability of the fan blade.

[0011] As a further improvement of the present invention, the fan blade is provided with a connecting portion for connecting with the silencing ring. To enhance the connection strength, the fan blade has a widened section in the area near the silencing ring.

[0012] As a further improvement of the present invention, the number of the first fan blades and the second fan blades are equal, and they are distributed in an alternating pattern of long and short blades. Preferably, the radial length of the first fan blade is 1.1 to 3.5 times the radial length of the second fan blade.

[0013] As a further improvement of the present invention, the radial position of the silencing ring on the first fan blade is located at approximately 0.9L1 from the blade root; the radial position of the silencing ring on the second fan blade is located at approximately 0.5L2 from the blade root.

[0014] As a further improvement of the present invention, the axial arrangement position of the silent ring satisfies the following: the axial position on the first fan blade is within the range of 0.3H1 to 0.7H1 of its axial height H1; and the axial position on the second fan blade is at 0.5H2 of its axial height H2.

[0015] As a further improvement of the present invention, the silent ring is made of high-temperature resistant and fatigue-resistant engineering plastic, which is selected from at least one of polypropylene (PP), polycarbonate (PC) or glass fiber reinforced nylon, so as to reduce weight and absorb vibration while ensuring strength.

[0016] Compared with the prior art, the fan blade assembly provided by the present invention has the following beneficial effects: 1. By introducing a silent ring made of annular plastic parts and rigidly connecting all fan blades into one piece in the radial center region, the overall rigidity of the fan blade assembly is significantly improved, effectively suppressing the vibration and resonance of the blades during high-speed rotation, thereby greatly reducing operating noise.

[0017] 2. The design of alternating long and short blades (first blade and second blade) can improve the flow field distribution, break the vortex shedding of a single frequency, further reduce aerodynamic noise and improve air volume and air pressure performance.

[0018] 3. For fan blades of different lengths, the silencer ring is designed at a specific radial ratio position (0.8L1 to 0.9L1 of the first fan blade and 0.3L2 to 0.7L2 of the second fan blade). This specific support position can balance the force on the blade, prevent the tip of the long blade from deforming, and ensure the reliability of long-term operation.

[0019] 4. The main body of the fan blade is made of metal stamping, and the silent ring is made of engineering plastic, which combines the high strength of metal with the shock absorption and lightweight characteristics of plastic. Attached Figure Description

[0020] Figure 1 This is a top view of the fan blade assembly of the present invention.

[0021] Figure 2 This is a three-dimensional structural diagram of the fan blade assembly of the present invention.

[0022] Figure 3 This is a partially enlarged schematic diagram of the fan blade and its connecting part of the present invention. Detailed Implementation

[0023] like Figure 1 As shown, this embodiment provides a fan, which generally includes a housing (not shown), a motor for providing driving force, and a fan blade assembly 100 disposed inside the housing. The motor is fixedly mounted at the center of the housing, and its output shaft is coaxially connected to the hub 110 of the fan blade assembly 100, for driving the fan blade assembly 100 to rotate around its own axis. The fan blade assembly 100 is generally ring-shaped, with multiple fan blades 120 arranged circumferentially around the hub 110 as the center. Each fan blade 120 extends radially outward and forms a ring, for accelerating and transporting the flowing air.

[0024] like Figure 1 As shown, the hub 110 is located at the center of the fan blade assembly 100, and its inner hole is interference-fitted or fitted with the fan shaft 301 to transmit the rotational torque output by the motor to the fan blade assembly 100. Several mounting portions 111 are provided circumferentially on the outer peripheral surface of the hub 110 for connecting to the inner ends of each fan blade 120.

[0025] like Figure 3 As shown, a plurality of fan blades 120 are arranged at intervals along the circumference of the hub 110, preferably at equal angles, and arranged in a ring. The fan blades 120 include a longer first fan blade 120A and a shorter second fan blade 120B, wherein the first fan blade 120A is of metal structure and the second fan blade 120B is of plastic structure, and the two together form a plurality of fan blades 120 that are a mixture of plastic and metal.

[0026] In this embodiment, each blade 120 is a metal structure. Specifically, each blade 120 includes a metal blade body 121 near the hub 110 and a plastic connecting portion 122 located outside the metal blade body 121. The metal blade body 121 is obtained, for example, from aluminum alloy sheet through stamping and bending to provide sufficient strength and rigidity. The plastic connecting portion 122 is a hole that covers or is embedded in the corresponding part of the mute ring for reliable connection with the mute ring 130, and provides a certain degree of buffering and vibration damping performance at the connection point. Figure 3 In the structure shown, the metal blade body 121 forms the main blade profile in the radial direction, while the plastic connecting part 122 is located near the radial center of the fan blade.

[0027] The noise reduction ring 130 is made of a ring-shaped plastic component, which is arranged around the hub 110 and located in the radial center region of the fan blade 120. For example... Figure 1 As shown, the silencing ring 130 extends continuously in the circumferential direction and contacts and is fixedly connected to the plastic connecting parts 122 of all fan blades 120. Specifically, each fan blade 120 is rigidly connected to the silencing ring 130 in its radial central region through the plastic connecting part 122, for example by means of plugging, snapping, or screw locking, so that the silencing ring 130 and each fan blade 120 form an integral support structure at this position, thereby playing a role in mutual restraint and support for each fan blade 120 when the fan blade assembly 100 rotates.

[0028] For ease of description, the radial length of the first blade 120A from the blade root (the end near the hub 110) to the blade tip (the end away from the hub 110) is denoted as L1. In this embodiment, the radial position of the silencing ring 130 is set approximately 0.9L1 from the blade root of the first blade 120A. The radial position of the silencing ring 130 is set approximately 0.5L2 from the blade root of the second blade 120B, roughly in the middle of the radial direction of the blades. It is sufficient to ensure that the silencing ring 130 is located in the main flexural deformation area of ​​the blade 120. This arrangement effectively limits the deformation and oscillation of the blade 120 in the middle region when the fan is running at high speed, reducing noise caused by blade flexing and airflow impact.

[0029] like Figure 2 and Figure 3 As shown, in the axial direction, the noise reduction ring 130 is preferably arranged within the range of 0.3L³ to 0.7L³ of the axial length L of the fan blade, that is, in the upper part of the middle of the fan blade. This position avoids the edge areas near the air inlet and outlet sides, and will not significantly block the air inlet or outlet, thereby reducing interference with the main airflow channel and ensuring air volume and air pressure output. On the other hand, it is located in the main flexural deformation zone of the fan blade in the axial direction, so that the noise reduction ring 130 can effectively support and constrain the middle of the fan blade, reduce the warping and slapping airflow phenomena of the fan blade in the axial direction, and further reduce operating noise. In addition, placing the noise reduction ring in the above-mentioned middle section can also maintain an appropriate distance between the noise reduction ring and the root and tip of the fan blade, avoiding adverse effects on the hub connection structure and the aerodynamic characteristics of the blade tip, thus improving structural rigidity and noise reduction while taking into account aerodynamic performance and energy efficiency.

[0030] In the axial direction, such as Figure 2 As shown, the silencing ring 130 is preferably positioned at approximately 0.5L of the axial length L4 of the second blade 120B, that is, basically located at the middle of the axial height of the second blade 120B. The axial height of the second blade 120B is approximately half the axial height of the first blade 120A. Since the axial height of the second blade 120B is approximately half the axial height of the first blade 120A, this distribution of long and short blades creates a staggered stepped boundary on the air outlet side, preventing all blades from cutting the airflow simultaneously on the same axial plane. This disperses vortex streets and periodic wakes, reduces aerodynamic noise of a single frequency, and thus lowers the overall operating noise. On the other hand, by reducing the axial height of some blades, the overall mass and moment of inertia of the blade assembly are effectively reduced while maintaining the number of circumferential blades and airflow, which is beneficial for improving start-stop characteristics and reducing bearing load. At the same time, the long and short blades complement each other in terms of force and stiffness, which optimizes the stiffness distribution of the entire blade ring in the axial direction and improves the structural stability of the blade assembly.

[0031] In this embodiment, the second fan blade 120B is a plastic fan blade. The annular plastic silent ring in the radial center region of the fan blade is an integral plastic structure with the second fan blade 120B. Under the premise of ensuring air volume output, it significantly improves the overall rigidity and stability of the fan blade assembly 100, effectively suppresses fan blade deformation and reduces fan operating noise.

[0032] Furthermore, in this embodiment, the metal blades of each first fan blade 120A are preferably made of aluminum alloy sheet or stainless steel sheet. After the metal sheet is cut, it is formed by stamping process once or multiple times to obtain the predetermined blade bending angle and torsional surface, thereby ensuring that the fan blade has the required strength and aerodynamic shape.

[0033] Based on the above embodiments, the radial cross-section of the silencing ring 130 in this embodiment is preferably designed as a regular rectangular cross-section or a circular cross-section; in other embodiments, the cross-section of the silencing ring 130 can also be a polygonal cross-section with chamfers, such as a trapezoidal or hexagonal structure with chamfered edges on both sides. To reduce the impact of the silencing ring 130 on the airflow and avoid the formation of sharp edges, rounded corners are provided on both axial sides of the silencing ring 130, so that the airflow can flow smoothly around the silencing ring 130 when it comes into contact with the airflow, thereby reducing the generation of eddies and noise, while reducing local stress concentration and improving the structural strength and service life of the silencing ring 130.

[0034] Based on the above embodiments, schematically, a plurality of through holes 131 are provided circumferentially at intervals on the annular body of the silent ring 130. The through holes 131 penetrate the wall thickness of the silent ring 130, allowing some airflow to pass through the silent ring 130, thereby reducing the obstruction effect of the silent ring on the airflow, and at the same time reducing the weight of the silent ring and reducing the moment of inertia, which is beneficial to improving the starting performance and operating efficiency of the fan.

[0035] Optionally, in this embodiment, each fan blade 120 is provided with a widened section 123 in the region away from the silencing ring 130, or, for example, the central region of the fan blade 120A is locally widened along the circumferential or radial direction to increase the cross-sectional modulus and the contact area with air in that region.

[0036] Based on the above embodiments, in this embodiment, the number of fan blades 120 included in the fan blade assembly 100 is preferably 50-150, and each fan blade 120 is distributed at equal angles along the circumferential periphery of the hub 110, wherein the first fan blade 120A and the second fan blade 120B each account for 50%. The second fan blade is a plastic fan blade, which can ensure airflow output while making the aerodynamic and centrifugal force distribution of the fan blade assembly 100 more uniform during rotation, thereby reducing the vibration of the whole machine and improving the balance and stability of the fan operation.

[0037] In a preferred embodiment, the fan blades 120 include a first fan blade 120A and a second fan blade 120B arranged alternately along the circumference, with an equal number of blades and an alternating distribution of long and short blades. The radial length of the first fan blade 120A is greater than the radial length of the second fan blade 120B, specifically in a ratio of 1.5 times (preferred to be within the range of 1.1 to 3.5 times). This design, through the alternating arrangement of long and short blades, breaks the periodic uniformity of airflow, avoids the superposition of periodic vortices generated by a single-length blade, and effectively suppresses resonance noise. Simultaneously, the length ratio of 1.1 to 3.5 times, verified through aerodynamic simulation and experiments, ensures both noise suppression and prevents uneven distribution of rotational inertia, thus ensuring the dynamic balance performance and operational stability of the fan blade assembly 100.

[0038] Furthermore, the mute ring 130 in this embodiment is made of a high-temperature resistant and fatigue-resistant engineering plastic material. Specifically, the material of the mute ring 130 can be selected from at least one of polypropylene (PP), polycarbonate (PC), or glass fiber reinforced nylon, or a combination of the above materials. By using the above-mentioned engineering plastic, the mute ring 130 can maintain good dimensional stability and mechanical properties under long-term high-speed rotation and repeated temperature changes, and is not prone to cracking, embrittlement, or permanent deformation. This ensures that the mute ring 130 provides continuous and reliable support and a quieting effect for the fan blade 120, further improving the service life and reliability of the fan blade assembly 100.

[0039] Through the above structural design, this application achieves significant technological progress while maintaining the output air volume and efficiency of the fan. First, the plastic silent ring 130 is precisely positioned in the main deflection area of ​​the radial center of the fan blade, and each fan blade 120 is constrained by an integrated support structure, effectively limiting the deformation and swaying of the fan blades during high-speed operation, and significantly improving the overall rigidity and structural stability of the fan blade assembly 100. Second, the silent ring significantly reduces the operating noise caused by blade deflection and structural resonance, improving the fan's quietness performance. Third, by using a hybrid structure for the first fan blade 120A and the second fan blade 120B, a good balance is achieved between strength, weight, and vibration reduction performance. Combined with refined designs such as through holes 131 / notches 132, cross-sectional optimization, and axial width limitation, aerodynamic losses and additional noise are effectively controlled. Therefore, compared with existing single-material blades or structures with only rigid reinforcing rings, this invention has significant comprehensive advantages in terms of noise reduction effect, deformation resistance, and service life.

[0040] The above is a summary of the technical features and description of the technical progress of the fan blade assembly 100 of this application. However, the present invention is not limited to the specific embodiments described above. Equivalent substitutions or modifications made without departing from the spirit and substance of the present invention shall fall within the protection scope of the present invention.

Claims

1. A fan blade assembly, characterized in that, include: The hub is used to connect to the fan shaft; A silent ring made of ring-shaped plastic parts; A plurality of fan blades are arranged circumferentially around the outer periphery of the hub, the fan blades including a first fan blade and a second fan blade arranged alternately in the circumferential direction, wherein the radial length of the first fan blade is greater than the radial length of the second fan blade; Each of the fan blades is rigidly connected to the silencing ring in its radial center region, so that the silencing ring and all the fan blades form an integral support structure; the radial position of the silencing ring on the first fan blade is within the range of 0.8L1 to 0.9L1 from the root of the first fan blade. The radial position of the silencing ring on the second fan blade is within the range of 0.3L2 to 0.7L2 from the blade root of the second fan blade; Wherein, L1 is the radial length of the first fan blade, and L2 is the radial length of the second fan blade.

2. The fan blade assembly according to claim 1, characterized in that, The fan blade includes a metal blade body, which is formed by stamping aluminum alloy or stainless steel sheet.

3. The fan blade assembly according to claim 2, characterized in that, The fan blades are provided with a connecting part for connection with the silencing ring.

4. The fan blade assembly according to claim 3, characterized in that, The fan blades have a widened section in the area near the silencing ring.

5. The fan blade assembly according to claim 3, characterized in that, The radial position of the silencing ring is set as follows: the second fan blade is located at approximately 0.5L2 from the blade root.

6. The fan blade assembly according to claim 3, characterized in that, The number of the first fan blades and the second fan blades are equal and they are distributed alternately in length.

7. The fan blade assembly according to claim 6, characterized in that, The radial length of the first blade is 1.1 to 3.5 times the radial length of the second blade.

8. The fan blade assembly according to claim 6, characterized in that, The axial arrangement of the silencing ring satisfies the following requirements: the axial position of the silencing ring on the first fan blade is within the range of 0.3H1 to 0.7H1 of the axial height H1 of the first fan blade; the axial position of the silencing ring on the second fan blade is at 0.5H2 of the axial height H2 of the second fan blade; wherein, H1 is the axial height of the first fan blade and H2 is the axial height of the second fan blade.

9. The fan blade assembly according to any one of claims 1 to 8, characterized in that, The noise reduction ring is made of high-temperature resistant and fatigue-resistant engineering plastic, which is one of polypropylene, polycarbonate or glass fiber reinforced nylon.

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