Centrifugal fan and electronic device

Abstract

The application provides a centrifugal fan and an electronic device, and relates to the technical field of electronic devices. The centrifugal fan comprises a shaft body and a plurality of fan blades. The shaft body has a first end and a second end opposite to each other in the axial direction of the shaft body, and the first end is used for air inlet. The plurality of fan blades are arranged on the circumferential side of the shaft body in the radial direction, and the side of the fan blades away from the shaft body forms an air outlet end for air outlet. The air outlet end is provided with a sawtooth structure, and the sawtooth structure comprises a plurality of sawteeth. The distance between the tooth tips of the plurality of sawteeth and the shaft body decreases in the axial direction from the first end to the second end.

Description

Technical Field

[0001] This application relates to the field of electronic equipment technology, and in particular to a centrifugal fan and electronic equipment. Background Technology

[0002] With the development of electronic devices, users have higher requirements for the noise performance of fans. How to reduce the aerodynamic noise of fans during operation to improve the user experience is an urgent problem to be solved. Utility Model Content

[0003] The purpose of this application is to provide a centrifugal fan and electronic device, the technical solution of which is as follows:

[0004] The first aspect of this application provides a centrifugal fan, comprising:

[0005] The shaft has a first end and a second end facing away from each other along its axial direction, the first end being used for air intake;

[0006] Multiple fan blades are arranged on the radial side of the shaft, and the side of the fan blades facing away from the shaft forms an air outlet for air outlet.

[0007] The air outlet is provided with a serrated structure, which includes multiple serrations. The distance between the tips of the multiple serrations and the shaft decreases along the axial direction from the first end to the second end.

[0008] In some embodiments, the aforementioned centrifugal fan has blades arranged in a centrally symmetrical plate shape, and the blades are centrally symmetrical with respect to the radial plane where the center point of the shaft is located; the end of the blade away from the shaft is divided into a first edge and a second edge along the center line, the first edge being closer to the first end than the second edge, and a serrated structure is provided on the first edge.

[0009] In some embodiments, the aforementioned centrifugal fan has the tips of the plurality of serrated teeth of the serrated structure recessed toward the shaft relative to the second edge; or, the tips of the plurality of serrated teeth of the serrated structure protrude away from the shaft relative to the second edge.

[0010] In some embodiments, the aforementioned centrifugal fan has a tooth root of the plurality of teeth of the serrated structure that is spaced at the same distance from the shaft.

[0011] In some embodiments, the aforementioned centrifugal fan has a plurality of serrations of the serrated structure of adjacent blades arranged in a staggered manner on a plane parallel to the axial direction.

[0012] In some embodiments, the aforementioned centrifugal fan includes a first segment and a second segment connected together. The end of the second segment opposite to the first segment is connected to the shaft. A serrated structure is provided at the end of the first segment opposite to the second segment. The second segment is tangent to the radial outer edge of the shaft. The first segment and the second segment have a preset angle to form an air outlet on the side opposite to the shaft.

[0013] In some embodiments, the aforementioned centrifugal fan, wherein the first segment has a target length L; the tooth height of the plurality of serrations decreases from 0.15L to 0.1L.

[0014] In some embodiments, the aforementioned centrifugal fan further includes: a retaining ring integrally formed on the side of the plurality of fan blades away from the shaft; the outer edge of the retaining ring is at least partially away from the shaft from the serrated structure of the fan blades.

[0015] In some embodiments, the aforementioned centrifugal fan is wherein the retaining ring and the centerline of the fan blades are in the same plane in the radial direction.

[0016] A second aspect of this application provides an electronic device, comprising:

[0017] The housing has a accommodating space;

[0018] A centrifugal fan, disposed within a containment space, wherein the centrifugal fan includes:

[0019] The shaft has a first end and a second end facing away from each other along its axial direction, the first end being used for air intake;

[0020] Multiple fan blades are arranged on the radial side of the shaft, and the side of the fan blades facing away from the shaft forms an air outlet for air outlet.

[0021] The air outlet is provided with a serrated structure, which includes multiple serrations. The distance between the tips of the multiple serrations and the shaft decreases along the axial direction from the first end to the second end.

[0022] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, the preferred embodiments of this application are described in detail below with reference to the accompanying drawings. Attached Figure Description

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

[0024] Figure 1 A schematic side view of the structure of a centrifugal fan according to an embodiment of this application is shown.

[0025] Figure 2 A schematic side view of the structure of a second centrifugal fan according to an embodiment of this application is shown.

[0026] Figure 3 A schematic side view of the structure of a third centrifugal fan according to an embodiment of this application is shown.

[0027] Figure 4 The diagram illustrates a three-dimensional structure of the sawtooth structure of adjacent blades of a centrifugal fan according to a third embodiment of this application, showing the projected misaligned arrangement of multiple sawtooth teeth on a plane parallel to the axial direction.

[0028] Figure 5 The schematic diagram shows a top view of a centrifugal fan blade according to an embodiment of this application;

[0029] Figure 6 The schematic diagram shows a top view of another centrifugal fan blade according to an embodiment of this application;

[0030] Figure 7 This schematic diagram illustrates the target length L and serration height of the first segment of the centrifugal fan according to an embodiment of this application.

[0031] Figure 8 The schematic diagram shows the isometric structure of a third type of centrifugal fan according to an embodiment of this application.

[0032] Explanation of reference numerals in the attached figures:

[0033] 1. Shaft; 11. First end; 12. Second end;

[0034] 2. Fan blade; 21. Air outlet; 22. Serrated structure; 23. First edge; 24. Second edge; 25. First segment; 26. Second segment; 221. Serrated tooth; 2211. Tooth tip; 2212. Tooth root;

[0035] 3. Protective ring;

[0036] A. Axial direction; B. Radial direction; R. Preset included angle. Detailed Implementation

[0037] The embodiments of this disclosure will be further described in detail below with reference to the accompanying drawings and examples. The detailed description of the embodiments and the accompanying drawings are used to illustrate the principles of this disclosure by way of example, but should not be used to limit the scope of this disclosure. This disclosure can be implemented in many different forms and is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

[0038] These embodiments are provided to make the disclosure thorough and complete, and to fully express the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specifically stated, the relative arrangement of components and steps, material composition, numerical expressions, and values ​​set forth in these embodiments should be interpreted as exemplary only and not as limiting.

[0039] It should be noted that, in the description of this disclosure, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicating orientation or positional relationship, are only for the convenience of describing this disclosure and simplifying the description, 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, and therefore should not be construed as a limitation of this disclosure. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0040] Furthermore, the terms "first," "second," and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different parts. "Vertical" is not strictly vertical, but within the permissible margin of error. "Parallel" is not strictly parallel, but within the permissible margin of error. Terms such as "including" or "contains" mean that the element preceding the word encompasses the element listed after the word, and do not exclude the possibility of encompassing other elements as well.

[0041] It should also be noted that, in the description of this disclosure, unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this disclosure depending on the specific circumstances. When a particular device is described as being located between a first device and a second device, an intermediary device may or may not be present between the particular device and the first or second device.

[0042] All terms used in this disclosure have the same meaning as understood by one of ordinary skill in the art to which this disclosure pertains, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant art, and not as idealized or highly formalized, unless expressly defined herein.

[0043] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0044] Example 1

[0045] like Figure 1 As shown, the first aspect of this application provides a centrifugal fan, including a shaft 1 and a plurality of fan blades 2; the shaft 1 has a first end 11 and a second end 12 opposite to each other along its axial direction A, the first end 11 being used for air intake; the plurality of fan blades 2 are disposed on the circumference of the shaft 1 in the radial direction B, and the side of the fan blades 2 opposite to the shaft 1 forms an air outlet end 21 for air exhaust; the air outlet end 21 is provided with a serrated structure 22, the serrated structure 22 including a plurality of serrations 221, the distance between the tooth tips 2211 of the plurality of serrations 221 and the shaft 1 decreasing along the axial direction A from the first end 11 to the second end 12.

[0046] Specifically, the first aspect of this application provides a centrifugal fan, which includes a shaft 1. The shaft 1 has a first end 11 and a second end 12 facing away from each other along its axial direction A. The first end 11 is used for air intake. The centrifugal fan also includes a plurality of fan blades 2, which are disposed on the periphery of the shaft 1 in the radial direction B. The side of the fan blades 2 facing away from the shaft 1 forms an air outlet end 21 for discharging airflow from the radial direction of the shaft 1.

[0047] This application provides a serrated structure 22 at the air outlet 21, i.e., the trailing edge of the fan blade 2. By providing the serrated structure 22, this application actively cuts the shear laminar flow channel leaving the fan blade 2 from the air outlet 21. The design inspiration of the serrated structure 22 comes from the wing tail shape of the secondary flight feathers of birds such as peregrine falcons in nature. The mechanism is that by cutting the shear laminar flow channel leaving the fan blade 2 from the air outlet 21 through the serrated structure 22, the shear laminar flow channel is cut into multiple small-scale, asynchronous small vortex structures, thereby suppressing the formation of large-scale vortices and reducing aerodynamic noise.

[0048] The sawtooth structure 22 includes multiple sawtooths 221. The distance between the tips 2211 of the multiple sawtooths 221 and the shaft 1 decreases along the axial direction A from the first end 11 to the second end 12. That is, the sawtooths 221 near the first end 11 of the shaft 1 are longer, and the length of the sawtooths 221 gradually decreases along the axial direction A from the first end 11 to the second end 12, forming a gradient decreasing distribution. When the airflow is blown out from the outlet end 21, the airflow speed is slower on the side near the first end 11 of the shaft 1, forming a thinner boundary layer. This boundary layer is easily detached from the surface of the fan blade 2 due to excessive disturbance, causing flow channel separation and resulting in a decrease in airflow. This application sets the sawtooths 221 near the first end 11 of the shaft 1 to be longer to provide stronger cutting ability, thereby improving laminar flow cutting efficiency, while maintaining boundary layer adhesion flow and reducing airflow loss. In the middle region of the airflow outlet 21, the airflow velocity is relatively high. The length of the sawtooth 221 set here is reduced compared to the side near the first end 11 of the shaft body 1. This is so that while the sawtooth 221 cuts the shear laminar flow channel, it avoids causing strong disturbances to the high-speed region with high airflow velocity. This reduces noise by suppressing the formation of large-scale vortices in the high-speed region without affecting the airflow pressure and stability.

[0049] Considering that the area from the first end 11 to the upper part of the shaft 1 is the main flow area where the fan blades 2 do work, and the area from the middle part to the second end 12 of the shaft 1 is the non-main flow area where the fan blades 2 do work, the airflow energy in the non-main flow area is weaker than that in the main flow area, resulting in a lower work capacity, this application sets the length of the sawtooth 221 to gradually decrease along the axial direction A from the first end 11 to the second end 12. This is to cut the shear laminar flow channel through the sawtooth 221 in the non-main flow area to suppress the formation of large-scale vortices, while avoiding excessive disturbances to suppress noise generation. Furthermore, this application achieves the matching of the sawtooth structure 22 with the flow field of the centrifugal fan outlet 21 by setting the length of the sawtooth 221 to gradually decrease along the axial direction A from the first end 11 to the second end 12. This improves the laminar flow cutting efficiency, maintains the boundary layer adhesion flow, reduces airflow loss, and suppresses the formation of large-scale vortices, thereby reducing noise.

[0050] This application provides a centrifugal fan, including a shaft 1 and a plurality of fan blades 2. The shaft 1 has a first end 11 and a second end 12 facing away from each other along its axial direction A. The first end 11 is used for air intake. The plurality of fan blades 2 are disposed on the circumference of the shaft 1 in the radial direction B, and the side of the fan blades 2 facing away from the shaft 1 forms an air outlet end 21 for air exhaust. The air outlet end 21 is provided with a serrated structure 22, which includes a plurality of serrations 221. The distance between the tips 2211 of the plurality of serrations 221 and the shaft 1 decreases along the axial direction A from the first end 11 to the second end 12. By providing a serrated structure 22 at the air outlet end 21 of the centrifugal fan, this application cuts the shear laminar flow channel leaving the fan blades 2 from the air outlet end 21 into a plurality of small-scale, asynchronous small vortex structures, thereby suppressing the formation of large-scale vortices and reducing aerodynamic noise. By gradually reducing the length of the sawtooth 221 along the axial direction A from the first end 11 to the second end 12, the flow field of the sawtooth structure 22 and the centrifugal fan outlet 21 is matched. This not only improves laminar flow cutting efficiency, maintains boundary layer adhesion flow, and reduces air volume loss, but also suppresses the formation of large-scale vortices and reduces noise.

[0051] like Figure 2 As shown, in some embodiments, the fan blade 2 is arranged in a centrally symmetrical plate shape, and the fan blade 2 is centrally symmetrical with respect to the radial plane where the center point of the shaft 1 is located; the end of the fan blade 2 away from the shaft 1 is divided into a first edge 23 and a second edge 24 along the center line, the first edge 23 is closer to the first end 11 than the second edge 24, and the serrated structure 22 is provided on the first edge 23.

[0052] Specifically, this application sets the fan blades 2 in a centrally symmetrical plate-like arrangement. The fan blades 2 are centrally symmetrical with respect to the radial plane where the center point of the shaft 1 is located. This is beneficial for the fan blades 2 to maintain good dynamic balance during high-speed rotation, avoid vibration or noise caused by structural asymmetry, and improve the operational stability of the centrifugal fan.

[0053] This application divides the end of the fan blade 2 away from the shaft 1 along the centerline into a first edge 23 and a second edge 24. The first edge 23 is closer to the first end 11 than the second edge 24. The serrated structure 22 is disposed on the first edge 23. That is, the first edge 23, closer to the first end 11 where the air enters, is the main flow area where the fan blade 2 does work, and the second edge 24 is the non-main flow area where the fan blade 2 does work. The flow channel stability of the main flow area corresponding to the first edge 23 directly affects the working efficiency of the centrifugal fan. By disposing the serrated structure 22 on the first edge 23, this application effectively cuts the shear laminar flow channel of the main flow area of ​​the centrifugal fan, suppresses the formation of large-scale vortices, and reduces aerodynamic noise.

[0054] Furthermore, in this application, the length of the sawtooth 221 gradually decreases along the axial direction A from the first end 11 to the second end 12. When the sawtooth structure 22 is set on the first edge 23, the length of the sawtooth 221 near the first end 11 of the shaft 1 is longer, and the length of the sawtooth 221 near the center of the shaft 1 is shorter. When the airflow blows out from the outlet end 21, the airflow speed is slower on the side near the first end 11 of the shaft 1, forming a thinner boundary layer. Due to excessive disturbance, the boundary layer is easily detached from the surface of the fan blade 2, causing flow channel separation and resulting in a decrease in airflow. In this application, the length of the sawtooth 221 near the first end 11 of the shaft 1 is longer to provide stronger cutting ability, thereby improving laminar flow cutting efficiency, while maintaining boundary layer adhesion flow and reducing airflow loss. In the middle region of the airflow outlet 21, the airflow velocity is relatively high. The sawtooth 221 set near the center of the shaft 1 in this application can cut the shear laminar flow channel with the sawtooth 221 while avoiding strong disturbance to the high-speed area with high airflow velocity. This reduces noise by suppressing the formation of large-scale vortices in the high-speed area without affecting the airflow pressure and stability.

[0055] like Figure 2 and Figure 3 As shown, in some embodiments, the tips 2211 of the plurality of serrations 221 of the serration structure 22 are recessed toward the shaft 1 relative to the second edge 24; or, the tips 2211 of the plurality of serrations 221 of the serration structure 22 are protruding away from the shaft 1 relative to the second edge 24.

[0056] Specifically, in this application, a sawtooth structure 22 is provided on the first edge 23, and the length of the sawtooth 221 gradually decreases along the axial direction A from the first end 11 to the second end 12. In one embodiment, the tips 2211 of the multiple sawtooth 221 of the sawtooth structure 22 are recessed relative to the second edge 24 toward the shaft 1. This allows for the introduction of a sawtooth structure 22 for cutting the airflow shear laminar flow channel at the outlet 21 without increasing the overall outer diameter of the centrifugal fan. This helps maintain the concentration of the airflow direction, reduces radial flow loss, improves the integrity of the outer edge of the structure, and optimizes the spatial layout.

[0057] In another embodiment, the tip 2211 of the multiple serrations 221 of the serrated structure 22 is set to protrude away from the shaft 1 relative to the second edge 24, so that the outwardly protruding serrations 221 have a greater cutting disturbance effect at the air outlet 21, which is conducive to better breaking up the large-scale vortex structure and improving the noise reduction effect.

[0058] like Figures 1 to 3 As shown, in some embodiments, the tooth roots 2212 of the plurality of teeth 221 of the sawtooth structure 22 are spaced at the same distance from the shaft 1.

[0059] Specifically, this application improves the structural consistency of the tooth roots 2212 of the sawtooth structure 22 by setting the spacing between the tooth roots 2212 of the multiple sawtooths 221 of the sawtooth structure 22 and the shaft 1, thereby enhancing the overall strength and fatigue resistance of the sawtooth structure 22 and improving the stability and reliability of the centrifugal fan under high-speed operation. Simultaneously, the equal spacing between the tooth roots 2212 and the shaft 1 makes the gradual decrease in the length of the sawtooths 221 along the axial direction A from the first end 11 to the second end 12 more significant structurally, forming a gradient structure for cutting. This reduces manufacturing difficulty and process complexity, ensuring that the gradient setting of the sawtooth structure 22 can stably cut the shear laminar flow channel of the air outlet 21, effectively suppressing the formation of large-scale vortices and reducing aerodynamic noise.

[0060] like Figure 4 As shown, in some embodiments, the multiple serrations 221 of the serration structure 22 of adjacent fan blades 2 are arranged in a staggered manner on a plane parallel to the axial direction A.

[0061] Specifically, in order to further enhance the cutting effect, this application sets the projections of multiple serrations 221 of the serration structure 22 of adjacent fan blades 2 in a staggered manner on a plane parallel to the axial direction A. The phase difference between the serrations 221 of adjacent fan blades 2 causes them to be in a staggered state, thereby causing the spatial position of the serrations 221 of different fan blades 2 cutting the airflow at the air outlet 21 to be different. This results in the phase dispersion of the pressure pulsation generated by the cutting airflow, thus generating a phase difference. The generated phase difference can cancel out the interference of the sound waves generated by different fan blades 2, weakening the coherence of the overall noise of the centrifugal fan and providing a good suppression effect on the periodic noise generated during the operation of the centrifugal fan.

[0062] In one embodiment, the distance between the center lines of adjacent sawtooth 221 in the axial direction A of the sawtooth structure 22 is one phase. This application can set the sawtooth structures 22 of adjacent fan blades 2 to differ by half a phase, that is, the tooth tip 2211 of the sawtooth 221 of one fan blade 2 is located in the gap between the two sawtooth 221 of adjacent fan blades 2. Alternatively, the sawtooth structures 22 of adjacent fan blades 2 can be set to differ by one-third phase, one-quarter phase, etc. The specifics are not limited, as long as noise reduction can be achieved by utilizing the principle of acoustic wave interference cancellation.

[0063] like Figure 5 and Figure 6 As shown, in some embodiments, the fan blade 2 includes a first segment 25 and a second segment 26 connected together. The end of the second segment 26 facing away from the first segment 25 is connected to the shaft 1. A serrated structure 22 is disposed at the end of the first segment 25 facing away from the second segment 26. The second segment 26 is tangent to the radial outer edge of the shaft 1. The first segment 25 and the second segment 26 have a preset included angle R to form an air outlet end 21 on the side facing away from the shaft 1.

[0064] Specifically, the fan blade 2 of this application includes a first segment 25 and a second segment 26 connected to each other. The end of the second segment 26 opposite to the first segment 25 is connected to the shaft 1. A serrated structure 22 is provided at the end of the first segment 25 opposite to the second segment 26. The second segment 26 is tangent to the radial outer edge of the shaft 1 to provide guidance so that the air can obtain a tangential vector when it is blown out. This can avoid the air impacting the fan blade 2 to achieve smooth air output, and can also avoid the turbulence phenomenon caused by airflow separation, while reducing noise.

[0065] A preset angle R is provided between the first segment 25 and the second segment 26. This preset angle R creates a smooth transition point at the connection between the first segment 25 and the second segment 26, changing the direction of the airflow. This causes the air in the airflow channel to be blown towards the outlet 21, using centrifugal force to convert kinetic energy into pressure energy. In some embodiments, the preset angle R can be an obtuse angle such as 120°, 135°, or 150°, changing the direction of the airflow tangent to the radial outer edge of the shaft 1, causing it to be blown towards the outlet 21.

[0066] The first segment 25 and the second segment 26 are arranged together to make the fan blade 2 bend as a whole. The second segment 26 provides tangential thrust, allowing air to rotate with the fan blade 2 and enter the airflow channel between the fan blades 2. The function of the first segment 25 is to blow the air in the airflow channel toward the air outlet 21 to convert kinetic energy into pressure energy using centrifugal force, thereby improving the static pressure capacity and air outlet efficiency of the centrifugal fan.

[0067] In one embodiment, such as Figure 6 As shown, this application optimizes the smoothness of the fan blade 2, which includes a first segment 25 and a second segment 26 connected together. A chamfer is made at the connection between the first segment 25 and the second segment 26 so that the airflow can transition smoothly when the airflow direction is changed, avoiding violent airflow disturbance and improving the stability of the fan operation.

[0068] like Figure 7 As shown, in some embodiments, the first segment 25 has a target length L; the tooth height of the plurality of serrations 221 decreases from 0.15L to 0.1L.

[0069] Specifically, this application considers the structural strength of the fan blade 2 and the effect of the serrated structure 22 in cutting and disrupting the airflow. The tooth height of the serration 221 is set based on the target length L of the first segment 25. It is considered that if the tooth height of the serration 221 is too large, fatigue fracture may easily occur during the cutting of the airflow, affecting the reliability of the fan blade 2. Furthermore, it may excessively interfere with the airflow, causing airflow loss and efficiency reduction. Conversely, if the tooth height of the serration 221 is too low, it cannot provide sufficient disturbance cutting capability to significantly affect the boundary layer, thus reducing noise reduction. Since the result is not obvious, this application sets the tooth height of multiple saw teeth 221 to decrease from 0.15L to 0.1L. That is, with the distance between the tooth tip 2211 of multiple saw teeth 221 and the shaft 1 decreasing along the axial direction A from the first end 11 to the second end 12, the tooth height of the largest saw tooth 221 is 0.15L, the tooth height of the smallest saw tooth 221 is 0.1L, and the tooth height of other saw teeth 221 decreases along the axial direction A from the first end 11 to the second end 12 to be obtained by interpolation between 0.15L and 0.1L.

[0070] like Figure 6 and Figure 8 As shown, in some embodiments, it further includes: a retaining ring 3, which is integrally formed on the side of the plurality of fan blades 2 away from the shaft body 1; the outer edge of the retaining ring 3 is at least partially away from the shaft body 1 from the serrated structure 22 of the fan blades 2.

[0071] Specifically, this application incorporates a protective ring 3 integrally formed on the side of multiple fan blades 2 facing away from the shaft 1. The protective ring 3 constrains the freedom of the air outlet end 21 of the fan blades 2 as its trailing edge, thereby suppressing fan blade vibration and improving operational stability. Simultaneously, by setting at least a portion of the outer edge of the protective ring 3 away from the shaft 1 from the serrated structure 22 of the fan blades 2, this application forms a physical protective barrier for the serrated structure 22, preventing damage from accidental collisions, scratches, or external impacts, thus improving structural durability and providing a stable noise reduction effect.

[0072] like Figure 8 As shown, in some embodiments, the centerline of the retaining ring 3 and the fan blade 2 are on the same plane in the radial direction B.

[0073] Specifically, this application sets the center lines of the retaining ring 3 and the fan blade 2 to be on the same plane in the radial direction B, so that the fan blade 2 and the retaining ring 3 are evenly and symmetrically distributed on the overall structure of the centrifugal fan, avoiding local mass shift, thereby improving the dynamic balance performance of the fan blade 2 and thus avoiding vibration or noise caused by mass shift during the operation of the centrifugal fan.

[0074] Example 2

[0075] A second aspect of this application provides an electronic device, including a housing and a centrifugal fan; the housing has an accommodating space; the centrifugal fan is disposed in the accommodating space, wherein the centrifugal fan includes: a shaft 1 and a plurality of fan blades 2; the shaft 1 has a first end 11 and a second end 12 opposite to each other along its axial direction A, the first end 11 being used for air intake; the plurality of fan blades 2 are disposed on the periphery of the shaft 1 in the radial direction B, and the side of the fan blades 2 opposite to the shaft 1 forms an air outlet end 21 for air exhaust; the air outlet end 21 is provided with a serrated structure 22, the serrated structure 22 including a plurality of serrations 221, the distance between the tooth tips 2211 of the plurality of serrations 221 and the shaft 1 decreasing along the axial direction A from the first end 11 to the second end 12.

[0076] For details on the specific structure of the centrifugal fan, please refer to Embodiment 1; it will not be repeated here.

[0077] A second aspect of this application provides an electronic device, including a housing and a centrifugal fan; the housing has an accommodating space; the centrifugal fan is disposed in the accommodating space, wherein the centrifugal fan includes: a shaft 1 and a plurality of fan blades 2; the shaft 1 has a first end 11 and a second end 12 facing away from each other along its axial direction A, the first end 11 being used for air intake; the plurality of fan blades 2 are disposed on the circumference of the shaft 1 in the radial direction B, and the side of the fan blades 2 facing away from the shaft 1 forms an air outlet end 21 for air exhaust; the air outlet end 21 is provided with a serrated structure 22, the serrated structure 22 including a plurality of serrations 221, the distance between the tooth tips 2211 of the plurality of serrations 221 and the shaft 1 decreasing along the axial direction A from the first end 11 to the second end 12. This application, by providing a serrated structure 22 at the air outlet end 21 of the centrifugal fan, cuts the shear laminar flow channel leaving the fan blades 2 from the air outlet end 21, causing the shear laminar flow channel to be cut into a plurality of small-scale, asynchronous small vortex structures, thereby suppressing the formation of large-scale vortices and reducing aerodynamic noise. By gradually reducing the length of the sawtooth 221 along the axial direction A from the first end 11 to the second end 12, the flow field of the sawtooth structure 22 and the centrifugal fan outlet 21 is matched. This not only improves laminar flow cutting efficiency, maintains boundary layer adhesion flow, and reduces air volume loss, but also suppresses the formation of large-scale vortices and reduces noise.

[0078] The embodiments of this disclosure have now been described in detail. To avoid obscuring the concept of this disclosure, some details known in the art have not been described. Those skilled in the art can fully understand how to implement the technical solutions disclosed herein based on the above description.

[0079] While specific embodiments of this disclosure have been described in detail by way of examples, those skilled in the art should understand that the examples are for illustrative purposes only and not intended to limit the scope of this disclosure. Those skilled in the art should understand that modifications can be made to the above embodiments or equivalent substitutions can be made to some technical features without departing from the scope and spirit of this disclosure. In particular, as long as there is no structural conflict, the technical features mentioned in the various embodiments can be combined in any manner.

Claims

1. A centrifugal fan, characterized in that, include: A shaft having a first end and a second end facing away from each other along its axial direction, the first end being used for air intake; Multiple fan blades are arranged on the circumference of the shaft in the radial direction, and the side of the fan blades facing away from the shaft forms an air outlet for air outlet; The air outlet end is provided with a serrated structure, which includes multiple serrations. The distance between the tips of the multiple serrations and the shaft decreases along the axial direction from the first end to the second end.

2. The centrifugal fan according to claim 1, characterized in that, The fan blades are arranged in a centrally symmetrical plate shape, and the fan blades are centrally symmetrical with respect to the radial plane where the center point of the shaft is located; The end of the fan blade away from the shaft is divided into a first edge and a second edge along the center line. The first edge is closer to the first end than the second edge, and the serrated structure is provided on the first edge.

3. The centrifugal fan according to claim 2, characterized in that, The tips of the plurality of teeth of the sawtooth structure are recessed toward the shaft relative to the second edge; or, The tips of the plurality of teeth of the sawtooth structure protrude away from the shaft relative to the second edge.

4. The centrifugal fan according to claim 3, characterized in that, The distance between the roots of the plurality of teeth of the sawtooth structure and the shaft is the same.

5. The centrifugal fan according to claim 1, characterized in that, The serrations of the serration structure of adjacent fan blades are arranged in a staggered manner on a plane parallel to the axial direction.

6. The centrifugal fan according to claim 2, characterized in that, The fan blade includes a first segment and a second segment connected together. The end of the second segment opposite to the first segment is connected to the shaft. The serrated structure is disposed at the end of the first segment opposite to the second segment. The second segment is tangent to the radial outer edge of the shaft, and the first segment and the second segment have a preset angle to form the air outlet on the side away from the shaft.

7. The centrifugal fan according to claim 6, characterized in that, The first segment has a target length L; The tooth height of the plurality of said saw teeth decreases from 0.15L to 0.1L.

8. The centrifugal fan according to claim 2, characterized in that, Also includes: A protective ring, which is integrally formed on the side of the plurality of fan blades away from the shaft body; The outer edge of the protective ring is at least partially opposite to the shaft body compared to the serrated structure of the fan blade.

9. The centrifugal fan according to claim 8, characterized in that, The protective ring and the centerline of the fan blade are on the same plane in the radial direction.

10. An electronic device, characterized in that, include: A housing having an accommodating space; Centrifugal fan, the centrifugal fan being disposed in the accommodating space, wherein the centrifugal fan comprises: A shaft having a first end and a second end facing away from each other along its axial direction, the first end being used for air intake; Multiple fan blades are arranged on the circumference of the shaft in the radial direction, and the side of the fan blades facing away from the shaft forms an air outlet for air outlet; The air outlet end is provided with a serrated structure, which includes multiple serrations. The distance between the tips of the multiple serrations and the shaft decreases along the axial direction from the first end to the second end.

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