Centrifugal fan and electronic device

Abstract

The invention provides a centrifugal fan and electronic equipment, the centrifugal fan comprises a shell, a rotating shaft and an impeller, the shell is provided with an air inlet and an air outlet, the impeller and the rotating shaft are arranged in a cavity defined by the shell, the rotating shaft is rotatably connected with the shell, the impeller is connected with the rotating shaft, the impeller comprises a hub and blades fixedly connected to the hub, and the blades are fixedly connected to the hub. Wherein the mean camber line of the airfoil of each blade is bent in the reverse direction of the rotating direction of the impeller, each mean camber line of the airfoil of each blade comprises a front edge end and a tail edge end, the front edge ends are located at the ends, close to the rotating shaft, of the blades, the tail edge ends are located at the ends, away from the rotating shaft, of the blades, and the front edge ends are located in front of the tail edge ends in the rotating direction of the impeller. Therefore, the centrifugal fan is in the sweepback C-shaped design, noise generated when the impeller rotates and flow loss of air can be reduced, increase of the air supply amount, reduction of the noise and improvement of energy efficiency during operation of the centrifugal fan are facilitated, a sound insulation box does not need to be additionally arranged outside the volute, and the overall size of the centrifugal fan is small.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the technical field of fan, in particular to a centrifugal fan and electronic equipment. BACKGROUND

[0002] With the continuous improvement of the performance of electronic equipment, the heat generated by the electronic equipment is more and more, which can be removed by air cooling through the fan. The working principle of the fan is to generate airflow by rotating the fan blade driven by the motor, and to generate forced convection in the electronic equipment to quickly remove the heat generated in the electronic equipment.

[0003] At present, consumers have higher demand for the thinness of electronic equipment, which limits the design space of the fan, and the performance and thinness of the fan need to be improved. SUMMARY

[0004] Embodiments of the present application provide a centrifugal fan and electronic equipment, which can balance the thin design and high performance of the centrifugal fan.

[0005] To achieve the above purpose, embodiments of the present application adopt the following technical solutions:

[0006] In a first aspect, a centrifugal fan is provided, comprising: a housing, a rotating shaft and an impeller, the housing is provided with an air inlet and an air outlet, the impeller and the rotating shaft are arranged in a cavity surrounded by the housing, the rotating shaft is rotatably connected with the housing, the impeller is connected with the rotating shaft, the impeller comprises: a hub and a blade fixedly connected to the hub, wherein the middle camber line of the airfoil of the blade is curved in the opposite direction of the rotation direction of the impeller, the middle camber line of the airfoil of the blade comprises: a leading edge end and a trailing edge end, the leading edge end is located at one end of the blade close to the rotating shaft, the trailing edge end is located at one end of the blade away from the rotating shaft, and the leading edge end is located in front of the trailing edge end in the rotation direction of the impeller.

[0007] Therefore, the centrifugal fan is designed as a backward-swept C type, the middle camber line of the airfoil of the blade is a C type line segment, which can be used in a scene with small exhaust resistance, the wind resistance of the blade at one end close to the rotating shaft is small and vortex is not easy to form, the air flow into the air flow channel between the blades is relatively smooth, which is beneficial to the air flow on the surface of the blade, can reduce the noise and flow loss of the air during the rotation of the impeller, is beneficial to the increase of the air supply amount, the reduction of the noise and the improvement of the energy efficiency during the operation of the centrifugal fan, can meet the requirement of small noise under large air supply amount without additional sound insulation box outside the housing, and can make the overall size of the centrifugal fan small, which is beneficial to the application of the centrifugal fan to the relatively thin electronic equipment.

[0008] In an optional implementation, the air inlet angle of the blade is less than 60°. The air inlet angle of the blade is the angle between the direction in which the tangent of the camber line of the airfoil of the blade at the leading edge end points to the outside of the impeller and the direction opposite to the rotation direction of the leading edge end when the impeller rotates. The air inlet angle of the blade is closer to the air inlet angle of the airflow when the airflow flows to the air inlet of the blade, so that the airflow into the airflow channel between the blades is smoother.

[0009] In an optional implementation, the air outlet angle of the blade is less than 90°. The air outlet angle of the blade is the angle between the direction in which the tangent of the camber line of the airfoil of the blade at the trailing edge end points to the outside of the impeller and the direction opposite to the rotation direction of the trailing edge end when the impeller rotates. Thus, the airflow channel of the blade gradually widens, the pressure decreases, and the air supply is increased.

[0010] In an optional implementation, the surface of the hub towards the air inlet comprises a first region connected with the rotation axis and a second region arranged around the first region. The second region comprises opposite first and second side edges. The first side edge of the second region is connected with the first region, and the second side edge of the second region is connected with the blade. The distance between the first side edge of the second region and the air inlet is less than the distance between the second side edge of the second region and the air inlet. The blade is divided into a first leading edge and a second leading edge by the connection position of the blade and the hub. The first leading edge of the blade is closer to the air inlet, and the second leading edge of the blade is farther away from the air inlet. Since the hub is arranged at the middle position of the air inlet end of the airflow channel of the blade, the second leading edge of the blade is shielded. The hub is divided into two regions in the application, and the second region of the hub gradually moves away from the air inlet. When the airflow flows into the shell through the air inlet, part of the airflow directly enters the airflow channel of the blade, and part of the airflow flows to the hub and is guided to the airflow channel by the hub. The second region of the hub is inclined towards the blade in the application, so that the airflow can be better guided to the airflow channel of the second leading edge of the blade, and the air inlet of the blade is more uniform.

[0011] In an optional implementation, in the direction away from the air inlet, the second region is inclined from the first side edge to the second side edge in the radial direction of the impeller. Thus, the second region is an inclined surface, and the airflow can be better guided to the second leading edge of the impeller. The inclination angle of the second region is not limited in the application, as long as the second region can guide the airflow to the air inlet end of the impeller. For example, the extension line of the second region can intersect the impeller.

[0012] In an optional implementation, in the direction away from the air inlet, the surface of the hub towards the air inlet is inclined from the rotation axis to the impeller in the radial direction of the impeller. Thus, the hub as a whole is inclined to the impeller, that is, the impeller is conical, and the airflow can be better guided to the impeller.

[0013] In an optional implementation, the leading edge of the blade comprises: a first leading edge and a second leading edge connected in sequence, the second end of the first leading edge and the first end of the second leading edge are connected with the hub, the first end of the first leading edge is close to the air inlet, and the distance between the first end of the first leading edge and the rotating shaft is greater than the distance between the second end of the first leading edge and the rotating shaft. Thus, the leading edge of the blade is divided into two parts, and the first leading edge of the blade gradually approaches the hub, so that when the airflow flows to the first leading edge of the blade, the angle between the airflow direction and the first leading edge of the blade is close to 90°, and the airflow can better enter the airflow channel of the blade.

[0014] In an optional implementation, the first leading edge is inclined to the rotating shaft in the radial direction of the impeller in a direction away from the air inlet. Thus, the airflow can be further made to enter the airflow channel of the blade. The inclination angle of the first leading edge is not limited in the embodiments of the present application, and only the angle between the airflow entering the air inlet and the leading edge of the blade is more conducive to the entry of the airflow. For example, the inclination angle of the first leading edge can be adjusted so that the angle between the airflow entering the air inlet and the first leading edge is close to 90°.

[0015] In an optional implementation, the second leading edge is parallel to the rotating shaft. Thus, the second leading edge can be used to receive the airflow guided by the hub, and by adjusting the guide angle of the hub, the airflow can be guided into the airflow channel of the second leading edge of the blade.

[0016] In an optional implementation, the distance between the first end of the second leading edge and the rotating shaft is greater than the distance between the second end of the second leading edge and the rotating shaft. Thus, the leading edge of the blade is divided into two parts, and the second leading edge of the blade gradually approaches the hub, so that when the hub guides the airflow to the second leading edge of the blade, the angle between the airflow direction and the second leading edge of the blade is close to 90°, and the airflow can better enter the airflow channel of the blade.

[0017] In an alternative implementation, the second leading edge is inclined towards the rotation axis in a direction away from the air inlet. In this way, the air flow can be further guided into the air flow passage of the blade. The present application does not limit the angle of inclination of the second leading edge, as long as the air flow from the air inlet can be guided into the air flow passage. For example, the angle of inclination of the second leading edge can be adjusted so that the air flow guided by the inclined surface of the hub (i.e. the inclined surface of the hub) is approximately 90° to the first leading edge. In an alternative implementation, the impeller comprises a plurality of the blades arranged at intervals along the circumference of the hub, and the air flow passage is formed between adjacent blades. The air inlet of the air flow passage is formed between the end portions of the adjacent blades close to the rotation axis, and the air outlet of the air flow passage is formed between the end portions of the adjacent blades away from the hub. The cross-section of the air flow passage gradually increases from the air inlet to the air outlet. In this way, the air flow speed gradually increases when the air flows through the air flow passage, which helps to increase the air delivery of the centrifugal fan and reduce the noise generated by the centrifugal fan.

[0018] In an alternative implementation, the camber line of the airfoil of the blade is a second-order Bezier curve, and the leading edge end and the trailing edge end are the start control point and the end control point of the second-order Bezier curve, respectively.

[0019] After the coordinates in the impeller polar coordinate system are converted into the coordinates in the blade rectangular coordinate system, the pole point in the impeller polar coordinate system is located on the rotation axis of the hub, the polar angle of the leading edge end in the impeller polar coordinate system is π / 2, the origin of the blade rectangular coordinate system is located at the leading edge end, the horizontal axis direction in the blade rectangular coordinate system is the same as the polar axis direction in the impeller polar coordinate system, and the positive direction of the vertical axis of the blade rectangular coordinate system is the direction in which the leading edge end points to the outside of the impeller in the radial direction of the impeller. Thus, the wind resistance of the blade at the end close to the rotation axis is small, and vortex is not easy to form, the air flow into the air flow passage is relatively smooth, the air flow adhering to the surface of the blade is facilitated, the noise and the flow loss of the air during rotation of the impeller are reduced, and the increase of the air supply amount, the reduction of the noise, and the improvement of the energy efficiency during operation of the centrifugal fan are facilitated. In addition, the air flow field in the air flow passage is highly consistent with the airfoil of the blade, the airfoil of the blade has strong resistance to the adverse pressure gradient, the air flow adhering to the surface of the blade is not easy to separate from the blade during rotation of the impeller, the air flow in the air flow passage is relatively smooth, the noise and the flow loss of the air during rotation of the impeller are reduced, and the increase of the air supply amount, the reduction of the noise, and the improvement of the energy efficiency during operation of the centrifugal fan are facilitated. Furthermore, the air flow field in the air flow passage is highly consistent with the airfoil of the blade, the aerodynamic performance of the blade is good, the work efficiency of the blade on the air during rotation is high, the energy efficiency during operation of the centrifugal fan is high, the air flow out of the air outlet end has high air pressure, and the air supply amount during operation of the centrifugal fan is high. The size of the blade can be adjusted according to the formula of the second-order Bezier curve, and different sizes of the centrifugal fan with large air supply amount and small noise can be manufactured. During the conversion of the coordinates in the impeller polar coordinate system into the coordinates in the blade rectangular coordinate system, the coordinates in the impeller polar coordinate system can be first converted into the coordinates in the impeller rectangular coordinate system through the conversion method of the polar coordinate system and the rectangular coordinate system, and then the coordinates in the impeller rectangular coordinate system are converted into the coordinates in the blade rectangular coordinate system through translation or other methods. The origin of the impeller rectangular coordinate system is located on the rotation axis, the horizontal axis in the impeller rectangular coordinate system coincides with the polar axis in the impeller polar coordinate system, the positive direction of the vertical axis of the impeller rectangular coordinate system is the direction in which the rotation axis points to the outside of the impeller in the radial direction of the impeller, the unit of the horizontal coordinate in the blade rectangular coordinate system is the same as the unit of the vertical coordinate, for example, the unit of the horizontal coordinate and the unit of the vertical coordinate in the blade rectangular coordinate system can be meters, decimeters, centimeters, etc.

[0020] In an optional implementation, the shell comprises a side wall, and oppositely arranged bottom plate and top plate, the side wall is between the top plate and the bottom plate, the side wall, the top plate and the bottom plate jointly enclose the cavity, the top plate is provided with an air inlet, and the side wall is provided with an air outlet. In this way, the centrifugal fan can take in air from the top plate and take out air from the side wall, the air flow in the shell is relatively smooth, the air flow speed in the shell is high, the noise during the operation of the centrifugal fan is reduced, and the air supply amount during the operation of the centrifugal fan is increased.

[0021] In an optional implementation, the rotating shaft is arranged between the top plate and the bottom plate, and the centrifugal fan comprises a cross beam arranged in the air inlet and connected with the top plate, a connecting portion and a convex portion, the connecting portion is used for connecting the convex portion and the top plate, the convex portion protrudes towards the bottom plate, and the convex portion is rotationally connected with the rotating shaft. In this way, the rotating shaft is limited by the cross beam and the convex portion, the rotating shaft is prevented from shaking up and down in the shell, and the anti-drop impact capability of the centrifugal fan is enhanced.

[0022] In an optional implementation, the thickness of the convex portion is greater than the thickness of the connecting portion. In this way, the thickness of the cross beam is increased to form the convex portion, and the rotating shaft is limited in the axial direction. In an optional implementation, a limiting piece is arranged on the side of the convex portion close to the bottom plate, and the rotating shaft is rotationally connected with the limiting piece. In this way, the rotating shaft is limited in the circumferential direction by the limiting piece arranged on the convex portion, the rotating shaft is prevented from moving left and right, the anti-impact capability is enhanced, and abnormal shaking sound is avoided.

[0023] In an optional implementation, the thickness of the convex portion is the same as the thickness of the connecting portion, and the convex portion is formed by bending the cross beam. In this way, the cross beam is bent to form the convex portion, and the weight of the cross beam is reduced.

[0024] In an optional implementation, the side of the convex portion close to the bottom plate is provided with a ring-shaped piece, and the rotating shaft is rotationally connected with the ring-shaped piece. In this way, the rotating shaft is limited in the circumferential direction by the ring-shaped piece arranged on the convex portion, the rotating shaft is prevented from moving left and right, the anti-impact capability is enhanced, and abnormal shaking sound is avoided.

[0025] In an optional implementation, the centrifugal fan further comprises a middle pipe sleeved outside the rotating shaft, the rotating shaft and the middle pipe are coaxially arranged, and the middle pipe and the bottom plate are integrally formed. In this way, the middle pipe and the bottom plate are integrally formed, the anti-impact capability of the centrifugal fan is enhanced, and the anti-drop protection performance of the centrifugal fan is further improved.

[0026] In an alternative implementation, the middle tube comprises a first portion and a second portion, the first portion is arranged close to the bottom plate, and the wall thickness of the first portion is greater than that of the second portion. In this way, the wall thickness of the middle tube close to the bottom plate is increased, partial reinforcement is achieved, and the drop impact resistance of the centrifugal fan can be further improved.

[0027] In an alternative implementation, the centrifugal fan further comprises a motor housing, a motor, and a first sealing ring, the motor housing is connected to the rotating shaft, the hub is arranged on a first surface of the motor housing, the motor is arranged on a second surface of the motor housing, and the first sealing ring is arranged between the motor and the middle tube. In this way, by arranging the first sealing ring, the airflow can be prevented from entering the middle tube through the gap between the motor and the middle tube, a labyrinth design is formed in the centrifugal fan, dust and water can be prevented, and the sealing performance of the centrifugal fan is improved.

[0028] In an alternative implementation, the centrifugal fan further comprises a bearing and a second sealing ring, the bearing and the second sealing ring are arranged in the middle tube, the bearing and the second sealing ring are sleeved on the rotating shaft, the bearing is rotationally connected to the rotating shaft, and the second sealing ring is arranged on a side of the bearing close to the top plate. In this way, by arranging the second sealing ring, the oil in the bearing can be prevented from leaking out, the airflow can be further prevented from entering the middle tube, dust and water can be prevented, and the sealing performance of the centrifugal fan is improved.

[0029] In a second aspect, an electronic device is provided, which comprises a heat generating module and a centrifugal fan as described above, and the centrifugal fan is used for dissipating heat of the heat generating module. In this way, the electronic device adopts the centrifugal fan described above, the heat dissipation performance of the electronic device is improved, and the thin and light design of the electronic device is facilitated. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 A structural schematic diagram of an electronic device provided by an embodiment of the present application is shown in FIG. 1;

[0031] Figure 2 A structural schematic diagram of a centrifugal fan provided by an embodiment of the present application is shown in FIG. 2;

[0032] Figure 3 A structural schematic diagram of a centrifugal fan provided by an embodiment of the present application is shown in FIG. 2; Figure 2 A disassembled structural schematic diagram of a centrifugal fan is shown in FIG. 3;

[0033] Figure 4 A top view of an impeller provided by an embodiment of the present application is shown in FIG. 4;

[0034] Figure 5 A top view of an impeller provided by an embodiment of the present application is shown in FIG. 4; Figure 2 A sectional view of A-A in FIG. 4 is shown in FIG. 5;

[0035] Figure 6AA structural schematic diagram of an impeller provided by an embodiment of the present application is shown in FIG. 1.

[0036] Figure 6B A structural schematic diagram of a top plate provided by an embodiment of the present application is shown in FIG. 6. Figure 6A A B-B sectional view of FIG. 6.

[0037] Figure 7 A structural schematic diagram of a blade provided by an embodiment of the present application is shown in FIG. 3.

[0038] Figure 8 A schematic diagram of a mean camber line of an airfoil of a blade in a rectangular coordinate system of the blade provided by an embodiment of the present application is shown in FIG. 4.

[0039] Figure 9 A structural schematic diagram of a top plate provided by an embodiment of the present application is shown in FIG. 6.

[0040] Figure 10 A structural schematic diagram of another top plate provided by an embodiment of the present application is shown in FIG. 7.

[0041] Figure 11 A structural schematic diagram of a middle tube provided by an embodiment of the present application is shown in FIG. 8.

[0042] Figure 12 A structural schematic diagram of a middle tube and a shell provided by an embodiment of the present application is shown in FIG. 9. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings.

[0044] Hereinafter, the terms "first", "second", and the like are used only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second", and the like can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0045] In addition, in the present application, the orientation terms such as "upper", "lower", and the like are defined with respect to the orientation in which the components in the drawings are placed, and it should be understood that these directional terms are relative concepts, which are used for relative description and clarification, and can be changed accordingly according to the change of the orientation in which the components are placed in the drawings.

[0046] The electronic device in the embodiments of the present application can be a mobile phone, a pad, a notebook computer, a smart home, a smart wearable device (for example, a smart watch, a smart bracelet, smart glasses, a smart helmet), a virtual reality (VR) electronic device, an augmented reality (AR) electronic device, and the like. The electronic device can also be a handheld device, a computing device, or other processing device connected to a wireless modem having a wireless communication function, a vehicle-mounted device, an electronic device in a 5G network or an electronic device in a future evolved public land mobile network (PLMN), and the like, which are not limited in the embodiments of the present application.

[0047] Figure 1 A schematic diagram of an electronic device provided in the embodiments of the present application is shown.

[0048] As shown in the figure, Figure 1 In the embodiments of the present application, the electronic device can include a housing 1, a heat generating module 2, and a centrifugal fan 3. The heat generating module 2 can be installed in the housing 1, and the centrifugal fan 3 can be installed on the housing 1. The housing 1 can have a first air inlet 4 and a first air outlet 5. The centrifugal fan 3 can be used to generate airflow to drive air at the heat generating module 2 to flow out of the housing 1 from the first air outlet 5. The air flowing out of the housing 1 from the first air outlet 5 can carry out heat in the housing 1 to improve the heat dissipation efficiency of the electronic device.

[0049] The heat generating module 2 can be any device that generates heat during operation and needs to be cooled. For example, the heat generating module 2 can be a mainboard module, a service board module, a power module, and the like. When the electronic device is running, the heat generating module 2 will generate heat, and the heat generated by the heat generating module 2 can be transferred to the air in the housing 1.

[0050] In some embodiments, the electronic device can further include a first printed circuit board (PCB), and the heat generating module 2 can be disposed on the first PCB. The heat generating module 2 and the first PCB can be disposed in a cavity of the housing 1. For example, the heat generating module 2 can include, but is not limited to, a central processing unit (CPU), a graphics processing unit (GPU), and the like.

[0051] The number of heat generating modules is not limited in the present application. The number of heat generating modules 2 included in the electronic device can be multiple or one, and the number and type of heat generating modules 2 can be selected and set according to requirements.

[0052] Figure 2 A structural schematic diagram of a centrifugal fan is provided in the embodiments of the present application. Figure 3 A structural schematic diagram of a centrifugal fan is provided in the embodiments of the present application. Figure 2 A structural schematic diagram of a centrifugal fan is provided in the embodiments of the present application.

[0053] As shown in the embodiments of the present application, the centrifugal fan 3 can include a housing 20, an impeller 10 and a rotating shaft 11, the housing 20 can be mounted on the shell 1 of the electronic device as shown, the impeller 10 and the rotating shaft 11 can be mounted in the housing 20, the rotating shaft 11 is rotationally connected with the housing 20, and the impeller 10 is connected with the rotating shaft 11. Figure 3 Figure 1 As shown in the embodiments of the present application, the centrifugal fan 3 can include a housing 20, an impeller 10 and a rotating shaft 11, the housing 20 can be mounted on the shell 1 of the electronic device as shown, the impeller 10 and the rotating shaft 11 can be mounted in the housing 20, the rotating shaft 11 is rotationally connected with the housing 20, and the impeller 10 is connected with the rotating shaft 11.

[0054] As shown in the embodiments of the present application, the centrifugal fan 3 can include a housing 20, an impeller 10 and a rotating shaft 11, the housing 20 can be mounted on the shell 1 of the electronic device as shown, the impeller 10 and the rotating shaft 11 can be mounted in the housing 20, the rotating shaft 11 is rotationally connected with the housing 20, and the impeller 10 is connected with the rotating shaft 11. Figure 2 As shown in the embodiments of the present application, the centrifugal fan 3 can include a housing 20, an impeller 10 and a rotating shaft 11, the housing 20 can be mounted on the shell 1 of the electronic device as shown, the impeller 10 and the rotating shaft 11 can be mounted in the housing 20, the rotating shaft 11 is rotationally connected with the housing 20, and the impeller 10 is connected with the rotating shaft 11.

[0055] As shown in the embodiments of the present application, the centrifugal fan 3 can include a housing 20, an impeller 10 and a rotating shaft 11, the housing 20 can be mounted on the shell 1 of the electronic device as shown, the impeller 10 and the rotating shaft 11 can be mounted in the housing 20, the rotating shaft 11 is rotationally connected with the housing 20, and the impeller 10 is connected with the rotating shaft 11.

[0056] As shown in the embodiments of the present application, the centrifugal fan 3 can include a housing 20, an impeller 10 and a rotating shaft 11, the housing 20 can be mounted on the shell 1 of the electronic device as shown, the impeller 10 and the rotating shaft 11 can be mounted in the housing 20, the rotating shaft 11 is rotationally connected with the housing 20, and the impeller 10 is connected with the rotating shaft 11.

[0057] As shown in the embodiments of the present application, the centrifugal fan 3 can include a housing 20, an impeller 10 and a rotating shaft 11, the housing 20 can be mounted on the shell 1 of the electronic device as shown, the impeller 10 and the rotating shaft 11 can be mounted in the housing 20, the rotating shaft 11 is rotationally connected with the housing 20, and the impeller 10 is connected with the rotating shaft 11.

[0058] In some embodiments, the second air inlet 201 is a circular opening whose axis coincides with the rotating shaft of the impeller 10.

[0059] In the embodiments of the present application, the centrifugal fan 3 can further include a driving motor 30, the driving motor 30 is used to drive the impeller 10 to rotate.​

[0060] The type of the driving motor 30 is not limited in the embodiments of the present application. For example, the driving motor 30 can include, but is not limited to, an electric motor, a hydraulic motor, etc.

[0061] In some examples, the driving motor 30 can include a stator 32 and a rotor 31, the stator 32, the rotor 31, the impeller 10 and the rotating shaft 11 are coaxially arranged, the stator 32 is fixedly connected with the shell 20, the rotor 31 is fixedly connected with the impeller 10, the rotor 31 is rotationally connected with the stator 32, the stator 32 is configured to drive the rotor 31 to rotate, so as to drive the impeller 10 to rotate relative to the shell 20.

[0062] For example, the centrifugal fan 3 can further include a second circuit board 40, the second circuit board 40 can be fixedly installed on the inner wall of the bottom plate 23, the driving motor 30 can be installed on the second circuit board 40, and the second circuit board 40 can be electrically connected with the driving motor 30 to supply power to the driving motor 30. The second circuit board 40 can adjust the voltage and current supplied to the driving motor 30 to achieve speed regulation of the driving motor 30. For example, the stator 32 of the driving motor 30 can be fixedly installed on the second circuit board 40 and electrically connected with the second circuit board 40.

[0063] For example, the stator 32 of the driving motor 30 can drive the rotor 31 to rotate through electromagnetic induction.

[0064] Figure 4 A top view of the impeller provided in the embodiments of the present application. Figure 5 A top view of the impeller provided in the embodiments of the present application. Figure 2 A top view of the impeller provided in the embodiments of the present application. Figure 4 A top view of the impeller provided in the embodiments of the present application. Figure 5 As shown in FIGS. 1, 2 and 3, in the embodiments of the present application, the impeller 10 includes a hub 200 and a plurality of blades 100 which are spaced apart along the circumferential direction of the hub 200, the blades 100 are fixedly connected with the hub 200, and the hub 200 is connected with the rotating shaft 11.

[0065] In some examples, the motor 30 further includes a motor shell 33. In the example in which the driving motor 30 includes the stator 32 and the rotor 31, the stator 32, the rotor 31, the hub 200, the motor shell 33 and the rotating shaft 11 are coaxially arranged, and the stator 32, the rotor 31, the motor shell 33 and the hub 200 are stacked along the z direction, the motor shell 33 can be arranged between the hub 200 and the rotor 31, wherein the motor shell 33 is fixedly connected with the rotating shaft 11, the motor shell 33 includes a first surface 33a and a second surface 33b which are opposite along the z direction, the hub 200 is fixedly connected with the first surface 33a of the motor shell 33, and the rotor 31 is fixedly connected with the second surface 33b of the motor shell 33.

[0066] This application does not limit the connection method between the blade 100 and the hub 200. For example, the blade 100 can be fixedly connected to the hub 200 by welding, snap-fitting, fastener connection, integral molding, etc.

[0067] For example, such as Figure 4 , Figure 6A As shown, the end of blade 100 near the rotating shaft 11 is connected to the outer wall of hub 200. In this way, hub 200 has a smaller impact on the airflow between two adjacent blades 100.

[0068] For example, the blades 100 of the impeller 10 can be evenly distributed along the circumference of the hub 200.

[0069] like Figure 4 As shown, the T direction is the rotation direction of the impeller 10. In this embodiment, two adjacent blades 100 and Figure 3 An airflow channel 300 is formed between the top plate 21 and the bottom plate 23. An air inlet 311 of the airflow channel 300 is formed between the ends of two adjacent blades 100 that are close to the rotating shaft 11, and an air outlet 331 of the airflow channel 300 is formed between the ends of two adjacent blades 100 that are away from the rotating shaft 11. The air inlet 311 is connected to the second air inlet 201.

[0070] The rotational outer contour formed by the rotational path of the end of blade 100 away from the rotation axis 11 forms an exhaust channel with the side wall 22, top plate 21, and bottom plate 23. The air outlet 331 passes through the exhaust channel and... Figure 2 The second air outlet 202 shown is connected, and when the impeller 10 rotates, air outside the casing 20 passes through it. Figure 2 The second air inlet 201 shown enters the airflow channel 300. The impeller 10 drives the air in the airflow channel 300 to make centrifugal motion, so that the air in the airflow channel 300 enters the exhaust channel through the air outlet 331. The exhaust channel guides the air that enters it to the second air outlet 202, so that the air in the housing 20 is blown out through the second air outlet 202.

[0071] In some examples where the second air inlet 201 is a circular opening whose axis coincides with the rotation axis of the impeller 10, the radius of the second air inlet 201 can be greater than the radius of the rotational inner contour formed by the rotational path of the end of the blade 100 near the rotation axis 11. That is, the radius of the second air inlet 201 can be greater than the distance between the end of the blade 100 near the rotation axis 11 and the rotation axis 11.

[0072] Figure 4 The airflow channel formed between two adjacent blades of the impeller is also shown, such as... Figure 4As shown, in some possible embodiments, the air inlet end 311 is located at one end of the airflow passage 300 close to the rotation shaft 11, and the air outlet end 331 is located at one end of the airflow passage 300 away from the rotation shaft 11.

[0073] From the air inlet end 311 to the air outlet end 331, the flow cross section of the airflow passage 300 gradually increases. In this way, when the air flows in the airflow passage, the flow rate gradually increases, which is beneficial to improve the air supply amount of the centrifugal fan 3 during operation, and can make the centrifugal fan 3 operate with smaller noise and larger air supply amount.

[0074] It should be noted that, in the present application, the description of the relative relationship of the air inlet end 311, the air outlet end 331 and other parts of the airflow passage 300 refers to the relative relationship of the parts of the same airflow passage 300, unless otherwise specified.

[0075] In the embodiments of the present application, the camber line 110 of the airfoil of the blade 100 includes a leading edge end 1111 and a trailing edge end 1121, the leading edge end 1111 is located at one end of the camber line 110 of the airfoil of the blade 100 close to the rotation shaft 11, and the trailing edge end 1121 is located at one end of the camber line 110 of the airfoil of the blade 100 away from the rotation shaft 11.

[0076] It should be noted that the airfoil of the blade 100 is the cross section of the blade 100, and the cross section where the airfoil of the blade 100 is located is perpendicular to the extension direction of the blade 100 extending from one end close to the bottom plate 23 to one end close to the top plate 21. For example, when the blade 100 extends along the axial direction of the rotation shaft of the impeller 10 from one end close to the bottom plate 23 to one end close to the top plate 21, the cross section where the airfoil of the blade 100 is located can be perpendicular to the rotation shaft of the impeller 10.

[0077] The camber line 110 of the airfoil of the blade 100 is a continuous line segment formed by the center of the inscribed circle of the profile of the airfoil of the blade 100, that is, the distance from a point on the camber line 110 of the airfoil of the blade 100 to the profile of the airfoil of the blade 100 on both sides is equal. After the camber line 110 of the airfoil of the blade 100 is determined, the profile of the airfoil of the blade 100 can be determined according to the distribution rule of the thickness of the blade 100, and then the shape of the blade 100 can be determined.

[0078] In some examples, the blade 100 can be a plate-shaped structure with equal thickness.

[0079] In the present application, the description of the relative relationship of the camber line 110, the leading edge end 1111, the trailing edge end 1121 and other structures on the blade 100 refers to the relative relationship of the structures on the same blade 100.

[0080] In the present application, the blades of the centrifugal fan are designed in a backward-swept C shape, that is, the camber line of the airfoil of the blade is a C-like line segment, and the blade is inclined substantially in the opposite direction of the rotation direction of the impeller.

[0081] As shown in Figure 4 the camber line 110 of the airfoil of the blade 100 is curved in the opposite direction of the rotation direction T of the impeller, that is, the opening direction of the camber line 110 of the airfoil of the blade 100 is toward the rotation direction of the impeller.

[0082] Furthermore, along the rotation direction T of the impeller 10, the leading edge end 1111 is located in front of the trailing edge end 1121, which means that the line connecting the leading edge end 1111 and the trailing edge end 1121 is an oblique line, and the oblique line is inclined in the opposite direction of the rotation direction T of the impeller 10. As shown in Figure 4 the line connecting the leading edge end 1111 and the trailing edge end 1121 is t, the line t is inclined in the opposite direction of the rotation direction T of the impeller 10, and the included angle θ between the line t and the tangent direction of the rotation direction T of the impeller 10 is obtuse.

[0083] Therefore, the centrifugal fan is designed in a backward-swept C shape, the camber line of the airfoil of the blade is a C-like line segment, and the blade is inclined backward, which can be used in a scene with small air resistance, the air resistance of the blade at one end close to the rotation shaft is small, and vortex is not easy to form, the air flow into the air flow passage is relatively smooth, the air is beneficial to flow on the surface of the blade, the noise and the flow loss of the air during rotation of the impeller can be reduced, the air supply amount during operation of the centrifugal fan can be increased, the noise can be reduced, and the energy efficiency can be improved, the centrifugal fan can meet the requirement of small noise under large air supply amount without the need of adding a sound insulation box outside the volute, the overall size of the centrifugal fan is small, and the centrifugal fan is beneficial to be applied to relatively thin electronic devices.

[0084] In some examples, the camber line 110 of the airfoil of the blade 100 can be a tangent-continuous curve. In this way, the blade 100 is easy to process and has low manufacturing cost.

[0085] In some examples, the camber line 110 of the airfoil of the blade 100 can be a curvature-continuous curve. In this way, during rotation of the impeller 10, the air in the air flow passage 300 is beneficial to flow on the surface of the blade 100, the air in the air flow passage 300 is not easy to separate from the surface of the blade 100 during flow, and the noise and the flow loss of the air during rotation of the impeller 10 can be reduced. In addition, the blade 100 has low processing difficulty and low manufacturing cost. Furthermore, the air in the air flow passage 300 has good adhesion effect on the surface of the blade 100, the air in the air flow passage 300 is not easy to separate from the surface of the blade 100 during flow, the noise during rotation of the impeller 10 is small, and the flow loss of the air is small.

[0086] In the embodiments of the present application, the blade 100 of the impeller 10 has an inlet angle a and an outlet angle β. The inlet angle a of the blade 100 is an angle between a direction in which a tangent of the camber line 110 of the airfoil of the blade 100 at the leading edge end 1111 points to the outside of the impeller 10 and a direction opposite to a rotation direction of the leading edge end 1111 when the impeller 10 rotates. The outlet angle β of the blade 100 is an angle between a direction in which a tangent of the camber line 110 of the airfoil of the blade 100 at the trailing edge end 1121 points to the outside of the impeller 10 and a direction opposite to a rotation direction of the trailing edge end 1121 when the impeller 10 rotates.

[0087] In the embodiments of the present application, in some possible implementations, the inlet angle a of the blade 100 can be less than or equal to 60°. At this time, the inlet angle a of the blade 100 is an angle between a direction in which the tangent of the camber line 110 at the leading edge end 1111 points to the outside of the impeller 10 and a direction opposite to a linear velocity of the leading edge end 1111 when the impeller 10 rotates.

[0088] In this way, the inlet angle a of the blade 100 is closer to an inlet angle of the airflow when the airflow flows to the inlet of the blade, which is beneficial to the air entering the airflow channel 300, and the airflow channel 300 has a smooth inlet, which is beneficial to the airflow channel 300 having a large inlet flow, and is beneficial to improving the air supply of the centrifugal fan 3.

[0089] In addition, the inlet end 311 is not easy to form a vortex, which is beneficial to reducing the noise generated by the rotation of the impeller 10 and the flow loss of the air.

[0090] In addition, the bending degree of the camber line 110 can be small, and the air is not easy to separate from the surface of the blade 100 when the air is guided to the surface of the blade 100 at the part corresponding to the camber line 110 of the surface of the blade 100, which is beneficial to reducing the noise generated by the rotation of the impeller 10 and the flow loss of the air.

[0091] For example, the inlet angle a of the blade 100 can include but is not limited to 30°, 45°, 55°, 60°, etc.

[0092] In some possible implementations, the outlet angle β of the blade 100 is less than 90°. At this time, the outlet angle β of the blade 100 is an angle between a direction in which the tangent of the camber line 110 at the trailing edge end 1121 points to the outside of the impeller 10 and a direction opposite to a linear velocity of the trailing edge end 1121 when the impeller 10 rotates.

[0093] In this way, the outlet angle β of the blade 100 is large, which can make the air flow out of the airflow channel 300 more smoothly, and is beneficial to improving the air supply of the centrifugal fan 3.

[0094] For example, the outlet angle β of the blade 100 can include but is not limited to 60°, 75°, 88°, etc.

[0095] In some possible embodiments, the leading edge end 1111 is located in front of the trailing edge end 1121 in the rotation direction of the impeller 10. In this way, the blade 100 with a smaller air inlet angle a is facilitated to have a larger air outlet angle β, so that the air flows out of the airflow passage 300 more smoothly. In some embodiments, the air inlet angle a is smaller than the air outlet angle β.

[0096] In this way, the camber line 110 curved towards the opposite direction of the rotation direction of the impeller 10 facilitates the blade 100 to form a smaller air inlet angle and a larger air outlet angle, a larger air exhaust volume, and can be used in a scenario with a smaller air exhaust resistance. The blade 100 has a smaller air resistance at the end close to the rotation shaft 11 and is less likely to form a vortex, so that the air flows into the airflow passage 300 more smoothly, and the air is facilitated to flow along the surface of the blade 100. The noise and the flow loss of the air during rotation of the impeller 10 are reduced, and the air supply volume during operation of the centrifugal fan 3 is increased, the noise is reduced, and the energy efficiency is improved.

[0097] Since the noise generated between the shell 20 and the impeller 10 during operation of the centrifugal fan 3 is smaller, at this time, it is not necessary to additionally install a sound insulation box outside the shell 20, so that the requirement of a smaller noise under a larger air supply volume is met, and the overall size of the centrifugal fan 3 is smaller, which facilitates the application of the centrifugal fan 3 to a thinner electronic device.

[0098] The present application does not limit the curvature of the airfoil of the blade, and in some embodiments, the camber line 110 of the airfoil of the blade 100 can be a second-order Bezier curve.

[0099] An example, Figure 8 A schematic view of a camber line of an airfoil of a blade in a blade rectangular coordinate system is provided in the present application. Wherein, the t direction is the positive direction of the horizontal axis of the blade rectangular coordinate system, the m direction is the positive direction of the vertical axis of the blade rectangular coordinate system, P0 is the starting control point, P1 is the intermediate control point, and P2 is the terminal control point.

[0100] As Figure 8 shown, in some possible embodiments, the camber line 110 of the airfoil of the blade 100 is a second-order Bezier curve, and the leading edge end 1111 and the trailing edge end 1121 are the starting control point P0 and the terminal control point P2 of the second-order Bezier curve, respectively.

[0101] In this way, the design and manufacture of the airfoil of the blade 100 are relatively easy. In addition, the aerodynamic performance of the formed blade 100 is good, the air in the airflow passage 300 is facilitated to flow along the surface of the formed blade 100 during rotation of the impeller 10, the air in the airflow passage 300 is less likely to separate from the surface of the blade 100 during flow, and the noise and the flow loss of the air during rotation of the impeller 10 are reduced.

[0102] In some examples in which the middle camber line 110 of the airfoil of the blade 100 is a second-order Bezier curve, after converting the coordinates in the impeller polar coordinate system into coordinates in the blade rectangular coordinate system, in the blade rectangular coordinate system, the pole point in the impeller polar coordinate system is located on the rotation axis 11, the polar angle of the leading edge end 1111 in the impeller polar coordinate system is π / 2, the origin of the blade rectangular coordinate system is located at the leading edge end 1111, the horizontal axis direction of the blade rectangular coordinate system is the same as the polar axis direction of the impeller polar coordinate system, and the positive direction of the vertical axis of the blade rectangular coordinate system is the direction in which the leading edge end 1111 points to the outside of the impeller 10 along the radial direction of the impeller 10.

[0103] The value of the second-order Bezier curve can be determined by a calculation formula thereof, which is m(t) = (1-t) 2 P0+2(1-t)tP1+t 2 P2, where t is a parameter, and the value range of t is usually between 0 and 1.

[0104] When t = 0, the point on the curve is located at the starting control point P0.

[0105] When t = 1, the point on the curve is located at the terminal control point P2.

[0106] When t changes between 0 and 1, the curve presents a smooth change, connecting the starting control point P0, the intermediate control point P1, and finally reaching the terminal control point P2.

[0107] In the present application, t satisfies: 0 < t < 1.

[0108] The coordinates of the P0 point can be (0, 0), the horizontal coordinate of the P2 point is greater than 0, and the vertical coordinate of the P2 point can be, for example, 1. The horizontal coordinate of the P1 point can be greater than the horizontal coordinate of the P2 point, the vertical coordinate of the P1 point is greater than 0 and less than the vertical coordinate of the P2 point.

[0109] Thus, the blade 100 has lower wind resistance at the end near the rotating shaft 11 and is less prone to forming vortices, allowing air to flow smoothly into the airflow channel 300. This facilitates airflow adhering to the surface of the blade 100, reducing noise and airflow losses during impeller 10 rotation, and improving the airflow volume, noise, and energy efficiency of the centrifugal fan 3. Furthermore, the airfoil of the blade 100 closely matches the airflow field within the airflow channel 300, and the airfoil's strong resistance to adverse pressure gradients makes it difficult for the air flowing against the blade 100 to separate from it during impeller 10 rotation. This ensures smoother airflow within the airflow channel 300, further reducing noise and airflow losses during impeller 10 rotation, and improving the airflow volume, noise, and energy efficiency of the centrifugal fan 3. Furthermore, due to the high degree of fit between the airfoil of the blade 100 and the airflow field within the airflow channel 300, the blade 100 exhibits good aerodynamic performance. This results in high work efficiency of the blade 100 during rotation, leading to higher energy efficiency for the centrifugal fan 3 during operation. Additionally, the air pressure exiting from the outlet 331 is relatively high, resulting in a higher airflow rate for the centrifugal fan 3. Moreover, the size of the blade 100 can be adjusted according to the formula of the second-order Bezier curve, facilitating the manufacture of centrifugal fans 3 of different sizes with larger airflow rates and lower noise levels.

[0110] In the process of converting coordinates in the impeller polar coordinate system to coordinates in the blade rectangular coordinate system, the coordinates in the impeller polar coordinate system can be converted to the impeller rectangular coordinate system first by the polar coordinate system to rectangular coordinate system conversion method, and then the coordinates in the impeller rectangular coordinate system can be converted to the blade rectangular coordinate system by translation and other methods.

[0111] In this system, the origin of the impeller rectangular coordinate system is located on the rotation axis 11. The horizontal axis of the impeller rectangular coordinate system coincides with the polar axis of the impeller polar coordinate system. The positive direction of the vertical axis of the impeller rectangular coordinate system is the direction from the rotation axis 11 along the radial direction of the impeller 10 to the outside of the impeller 10. The units of the horizontal and vertical coordinates in the blade rectangular coordinate system are the same. For example, the units of the horizontal and vertical coordinates in the blade rectangular coordinate system can be meters, decimeters, centimeters, etc.

[0112] The centrifugal fan provided in this application embodiment has a blade 100 with a mid-arc 110 that adopts a second-order Bézier curve. This reduces noise and airflow loss during impeller rotation, which is beneficial for increasing air volume, reducing noise, and improving energy efficiency during centrifugal fan operation. Furthermore, the blade size can be adjusted according to this second-order Bézier curve, making it easy to manufacture centrifugal fans of different sizes with larger air volume and lower noise.

[0113] In the present application, when the air flow flows into the shell 20 through the second air inlet 201, part of the air flow directly enters the air flow passage of the blade 100 (such as the air flow a in Figure 5 , and part of the air flow flows to the upper surface of the hub 200 (such as the air flow b in Figure 5 , and the air flow is guided by the hub 200 to the air inlet end of the blade 100. However, when the hub 200 is parallel to the top plate 21, most of the air flow is guided to the first leading edge 101 of the blade 100, and the air outlet of the centrifugal fan is uneven, which affects the heat dissipation effect. As shown in Figure 5 , Figure 7 , the blade 100 can be divided into the first leading edge 101 and the second leading edge 102 connected with the first leading edge 101 as the dividing line, the first leading edge 101 of the blade 100 is closer to the second air inlet 201, and the second leading edge 102 of the blade 100 is located on the side away from the second air inlet 201.

[0114] Therefore, the structure of the hub 200 is improved in the present application. Figure 6A A structure schematic diagram of an impeller provided by an embodiment of the present application is provided. Figure 6B A B-B sectional view in Figure 6A . As shown in Figure 6A , Figure 6B , the hub 200 includes a first region 2001 and a second region 2002, as shown in Figure 5 , the first region 2001 is connected through the motor shell 33 and the rotating shaft 11, and the second region 2002 is arranged around the first region 2001, wherein the second region 2002 includes opposite first and second side edges, the first side edge of the second region 2002 is connected with the first region 2001, the second side edge of the second region 2002 is connected with the blade 100, and the first side edge of the second region 2002 is higher than the second side edge of the second region 2002.

[0115] In the present application, the hub 200 is divided into two regions, and the second region 2002 of the hub 200 gradually moves away from the second air inlet 201, when the air flow flows into the shell through the second air inlet 201, part of the air flow directly enters the air flow passage of the blade 100 (such as the air flow a in Figure 5 , and part of the air flow flows to the hub 200 (such as the air flow b in Figure 5 , and the air flow is guided by the hub 200 to the air flow passage of the blade 100. Since the hub 200 is arranged at the middle position of the air inlet end of the air flow passage of the blade 100, it will block the second leading edge 102 of the blade 100. In the present application, the second region 2002 of the hub 200 gradually inclines towards the blade 100, which can better guide the air flow to the air flow passage of the second leading edge of the blade 100, so that the air inlet of each position of the blade 100 is more uniform.

[0116] In some embodiments, the second region 2002 is inclined towards the second side along the radial direction of the impeller away from the second air inlet 201. That is, the second region 2002 is a slope. In this way, the air flow can be guided to the second leading edge 102 of the blade 100 through the second region 2002, so that the air intake of each position of the blade 100 is more uniform, and the performance of the fan is improved.

[0117] In an example, the hub 200 is in the shape of a circular truncated cone as a whole, wherein the first region 2001 of the hub 200 is the top surface of the circular truncated cone, and the second region 2002 of the hub is the side surface of the circular truncated cone. The longitudinal section of the hub 200 can be approximately isosceles trapezoidal. In this way, the inclination angle of the second region 2002 of the hub 200 is uniform along the circumferential direction, which can more uniformly guide the air flow to the second leading edge 102 of the blade, so that the air intake of each position of the blade 100 is more uniform, and the performance of the fan is improved.

[0118] The inclination angle of the second region 2002 is not limited in the embodiments of the present application, as long as the second region 2002 can guide the air flow to the air inlet end of the second leading edge of the blade. In an example, the extension line of the second region 2002 can intersect the second leading edge 102 of the blade. In this way, the air flow can be better guided into the air flow passage of the second leading edge 102 of the blade 100.

[0119] In some embodiments, the hub 200 as a whole can adopt a slope design, that is, in the direction away from the second air inlet 201, the surface of the hub 200 towards the air inlet 201 is inclined towards the blade 100 along the radial direction of the impeller. In this way, the air flow can be guided to the second leading edge 102 of the blade through the upper surface of the hub 200, so that the air intake of each position of the blade 100 is more uniform, and the performance of the fan is improved. Wherein, the radial direction is the straight line direction along the diameter or radius, or the straight line direction perpendicular to the rotation axis 11.

[0120] In an example, the hub 200 is in the shape of a circular truncated cone as a whole, wherein the first region 2001 of the hub 200 is the top surface of the circular truncated cone, and the second region 2002 of the hub is the side surface of the circular truncated cone. The longitudinal section of the hub 200 can be approximately isosceles trapezoidal. In this way, the inclination angle of the second region 2002 of the hub 200 is uniform along the circumferential direction, which can more uniformly guide the air flow to the second leading edge 102 of the blade, so that the air intake of each position of the blade 100 is more uniform, and the performance of the fan is improved.

[0121] The inclination angle of the hub 200 as a whole is not limited in the embodiments of the present application, as long as the hub 200 can guide the air flow to the air inlet end of the second leading edge of the blade. In an example, the extension line of the hub 200 can intersect the second leading edge 102 of the blade. In this way, the air flow can be better guided into the air flow passage of the second leading edge 102 of the blade 100.

[0122] In the embodiment, the hub 200 is conical, and the hub 200 gradually moves away from the second air inlet 201 in the direction close to the blade 100. When the air flow flows into the shell through the second air inlet 201, part of the air flow directly enters the air flow channel of the blade 100 (for example, air flow a in Figure 5 ), part of the air flow flows to the hub 200 (for example, air flow b in Figure 5 ), and is guided to the air flow channel of the blade 100 by the hub 200. In the application, the hub 200 gradually inclines towards the blade 100, which can better guide the air flow to the air flow channel of the second leading edge of the blade 100, so that the air intake of each position of the blade 100 is more uniform. The entire hub 200 adopts a conical design, which can better guide the air flow to the blade.

[0123] In order to better guide the air flow to the air flow channel, in some embodiments, the shape of the air inlet end of the air flow channel can also be adjusted. Figure 7 A structural schematic diagram of a blade is provided for the embodiment of the application. As shown in Figure 6B , Figure 7 , the blade 100 includes a leading edge close to the rotating shaft 11, and the leading edge of the blade includes a first leading edge 101 and a second leading edge 102 connected in sequence. The first leading edge 101 includes opposite first and second ends 101A and 101B, and the second leading edge 102 includes opposite third and fourth ends 102A and 102B. The first end 101A of the first leading edge 101 is close to the second air inlet 201, the second end 101B of the first leading edge 101 and the third end 102A of the second leading edge 102 are connected with the hub 200, and the fourth end 102B of the second leading edge 102 is away from the second air inlet 201.

[0124] As shown in Figure 6B , the distance between the first end of the first leading edge 101 and the rotating shaft 11 is greater than the distance between the second end of the first leading edge 101 and the rotating shaft 11.

[0125] The leading edge of the blade is divided into two parts, and the first leading edge 101 of the blade 100 gradually approaches the hub 200, as shown in the enlarged view c in Figure 6B , when the air flow a flows to the first leading edge 101 of the blade, the angle d between the direction of the air flow a and the first leading edge 101 of the blade is close to 90°, so that the air flow a can better enter the air flow channel of the blade.

[0126] As an example, in the direction away from the second air inlet 201, the first leading edge 101 inclines towards the rotating shaft 11 in the radial direction of the impeller.

[0127] The application does not limit the inclination angle of the first leading edge, only needs to make the angle between the air flow entering the air inlet and the leading edge of the blade more conducive to air entering. For example, the inclination angle of the first leading edge 101 can be adjusted so that the angle between the air flow a entering the air inlet and the first leading edge 101 is close to 90°, so that the air flow a can better enter the air flow channel of the blade 100.

[0128] In addition, the first leading edge 101 adopts an inclined design, that is, the air inlet end surrounded by the first leading edge adopts an inclined design, so that the air inlet end is open, the opening size of the air inlet end is increased, and the air inlet amount of the air inlet end is improved.

[0129] The application does not limit the extension direction of the second leading edge 102. In some embodiments, the second leading edge 102 is parallel to the rotating shaft 11. The second leading edge 102 can have an error of 0-5° with the rotating shaft 11.

[0130] Therefore, the second leading edge can be used to receive the air flow guided by the hub, and by adjusting the guide angle of the hub, the air flow can be guided into the air flow channel of the second leading edge of the blade.

[0131] In other embodiments, the distance between the first end of the second leading edge 102 and the rotating shaft is greater than the distance between the second end of the second leading edge 102 and the rotating shaft.

[0132] Therefore, the leading edge of the blade is divided into two parts, and the second leading edge of the blade gradually approaches the hub, so that when the hub guides the air flow to the second leading edge of the blade, the angle between the air flow direction and the second leading edge of the blade is close to 90°, so that the air flow can better enter the air flow channel of the blade.

[0133] For example, as shown in Figure 6B In the direction away from the second air inlet 201, the second leading edge 102 is inclined to the rotating shaft 11 in the radial direction of the impeller.

[0134] The application does not limit the inclination angle of the second leading edge, only needs to make the angle between the air flow entering the air inlet and the leading edge of the blade more conducive to air flow entering. For example, the inclination angle of the second leading edge can be adjusted so that the angle between the air flow guided by the inclined surface of the hub (that is, the inclined surface of the hub) and the first leading edge is close to 90°, so that the air flow can better enter the air flow channel of the blade.

[0135] Next, referring to Figure 7 In some embodiments of the application, as shown in Figure 7 The blade 100 further includes a transition portion 103, the transition portion 103 protrudes from the blade 100, and the transition portion 103 is used to connect with the hub 200.

[0136] The transition portion 103 comprises a first surface 1031 and a second surface 1032 connected to each other, and the first surface 1031 is connected to the first leading edge 101 of the blade 100. The first surface 1031 can be an arc surface, so that the transition between the first surface 1031 and the surface of the hub 200 is smoother, and the airflow can be better guided to the airflow channel of the blade 100.

[0137] The second surface 1032 of the transition portion 103 is used to connect to the hub 200. In some embodiments, the second surface 1032 can be a bevel surface, and is matched with the shape of the hub 200, so that the contact surface with the hub 200 is larger, and the connection is more stable.

[0138] Referring to Figure 7 , the blade 100 can further comprise a groove 104 connected to the second surface 1032 of the transition portion 103. The groove 104 is matched with the shape of the edge of the hub 200, for example. When the blade 100 is connected to the hub 200, the part of the hub 200 connected to the second surface 1032 of the transition portion 103, and the edge part of the hub 200 extends into the groove 104 and is clamped with the groove 104, so that the stability of the connection between the blade 100 and the hub 200 is further improved.

[0139] In order to improve the impact resistance of the centrifugal fan, in some embodiments, as shown in Figure 3 , Figure 9 , a cross beam 211 can be arranged on the top plate 21 to limit the rotation shaft 11, so that the rotation shaft 11 does not shake up and down in the shell. In an example, the cross beam 211 is arranged in the second air inlet 201. The cross beam 211 is connected to the upper cover, and the cross beam 211 comprises a connecting portion 213 and a convex portion 212 protruding towards the bottom plate 23. The convex portion 212 is rotationally connected to the rotation shaft 11. In some embodiments, the gap between the cross beam 211 and the upper end of the rotation shaft 11 can be 0.1-0.3 mm.

[0140] In this way, by arranging the cross beam 211 on the top plate 21 and arranging the convex portion 212 on the cross beam 211, the rotation shaft 11 can be limited, so that the rotation shaft 11 does not shake up and down in the shell, and the ability of the centrifugal fan to resist drop impact is enhanced.

[0141] The structure of the convex portion 212 is not limited in the embodiments of the present application. In some embodiments, as shown in Figure 9 , the thickness of the convex portion 212 is greater than the thickness of the connecting portion 213. That is, the thickness of the cross beam 211 can be increased to form the convex portion 212 on the cross beam 211, so that the rotation shaft 11 is limited in the axial direction Figure 5 (z direction) as shown. Figure 5 ​

[0142] The forming manner of the convex portion 212 is not limited in the embodiments of the present application. In some examples of the embodiments, the convex portion 212 and the connecting portion 213 can be integrally formed.

[0143] In some other examples of the embodiments, the convex portion 212 and the connecting portion 213 can be separately formed and then connected.

[0144] In some other embodiments, as shown in FIG. 2B, the convex portion 212 and the connecting portion 213 have the same thickness, and the convex portion 212 can be formed by bending the cross beam 211. In this way, the convex portion 212 can be formed on the cross beam 211 by bending the cross beam 211, which can reduce the weight of the cross beam 211, save materials, and facilitate the miniaturization and lightening of the centrifugal fan. Figure 10 In order to further improve the impact resistance of the centrifugal fan, in some embodiments, as shown in FIG. 2C, a limiting member can be further arranged on the side of the convex portion 212 close to the bottom plate, and the rotating shaft 11 extends into the limiting member, and the rotating shaft 11 and the limiting member can be rotatably connected.

[0145] Figure 9 In this way, by arranging the limiting member on the convex portion 212, the left and right movement of the rotating shaft 11 can be avoided, which can enhance the impact resistance and also facilitate the avoidance of shaking noise.

[0146] The structure of the limiting member 214 is not limited in the embodiments of the present application. In the case where the thickness of the convex portion 212 is greater than the thickness of the connecting portion 213, referring to FIG. 2D, the limiting member 214 can be a limiting groove arranged on the convex portion 212. For example, a limiting groove can be arranged on the surface of the convex portion 212 facing the bottom plate, so that the rotating shaft 11 extends into the limiting groove, and the rotating shaft 11 and the limiting groove can be rotatably connected.

[0147] In this way, by arranging the limiting groove on the convex portion 212, the left and right movement of the rotating shaft 11 can be avoided, which can enhance the impact resistance and also facilitate the avoidance of shaking noise. Figure 9 In the case where the thickness of the convex portion 212 is equal to the thickness of the connecting portion 213, that is, the convex portion 212 can be formed by bending the cross beam 211, referring to FIG. 2E, the limiting member 214 can be a ring-shaped member 215 arranged on the convex portion 212. For example, a ring-shaped member 215 can be arranged on the surface of the convex portion 212 facing the bottom plate, so that the rotating shaft 11 extends into the ring-shaped member 215, and the rotating shaft 11 and the ring-shaped member 215 can be rotatably connected.

[0148] In this way, by arranging the ring-shaped member 215 on the convex portion 212, the left and right movement of the rotating shaft 11 can be avoided, which can enhance the impact resistance and also facilitate the avoidance of shaking noise.

[0149] Figure 10

[0150] ​​​Therefore, by arranging the annular member 215 on the convex portion 212, the rotating shaft 11 can be prevented from moving left and right, and the impact resistance can be enhanced, and the shaking noise can be avoided.

[0151] To further improve the impact resistance of the centrifugal fan, in some embodiments, as shown in Figure 5 , the centrifugal fan further comprises a middle tube 231 arranged on the outside of the rotating shaft 11, the rotating shaft 11 and the middle tube 231 are coaxially arranged, and the middle tube 231 can be integrally formed with the bottom plate 23. Therefore, by integrally forming the middle tube 231 with the bottom plate 23, the impact resistance of the centrifugal fan is enhanced, and the drop protection performance of the centrifugal fan can be further improved.

[0152] Figure 11 A structural schematic diagram of the middle tube provided in the embodiments of the present application. Figure 12 A structural schematic diagram of the middle tube and the shell provided in the embodiments of the present application. In some embodiments, as shown in Figure 11 , Figure 12 the middle tube 231 comprises a first portion 231a and a second portion 231b, the first portion 231a is arranged close to the bottom plate 23, and the wall thickness of the first portion 231a is greater than that of the second portion 231b. Therefore, by increasing the wall thickness of the part of the middle tube 231 close to the bottom plate 23, the local strengthening is realized, and the drop impact resistance of the centrifugal fan can be further improved.

[0153] To improve the dustproof and waterproof performance of the centrifugal fan, in some embodiments, as shown in Figure 5 , Figure 11 , Figure 12 the centrifugal fan further comprises a first sealing ring 232 arranged between the motor and the middle tube 231. Therefore, by arranging the first sealing ring 232, the airflow can be prevented from entering the middle tube 231 through the gap between the motor and the middle tube 231, which is beneficial to realize dustproof and waterproof, and the sealing performance of the centrifugal fan is improved.

[0154] The structure of the first sealing ring 232 is not limited in the embodiments of the present application, and in some embodiments, the projection of the first sealing ring 232 on the side wall is in an inverted T shape. That is, the first sealing ring 232 comprises a first sealing portion 232a and a second sealing portion 232b, the first sealing portion 232a is arranged in the gap between the rotor 31 and the stator 32 of the motor for example, and the second sealing portion 232b is arranged in the gap between the rotor 31 of the motor and the middle tube 231 for example, the first sealing portion 232a can extend in the direction of the impeller, that is, the thickness of the first sealing portion 232a is greater than that of the second sealing portion 232b, so that the first sealing ring 232 is designed in an inverted T shape as a whole.

[0155] In this way, the airflow channel in the centrifugal fan is in a labyrinth design, and the sealing performance of the centrifugal fan is further improved.

[0156] In some embodiments of the present application, as shown in Figure 5 、 Figure 12 The centrifugal fan further comprises a bearing 111 sleeved on the rotating shaft 11, and the bearing 111 is arranged in the middle pipe 231, and a gap is arranged between the bearing 111 and the rotating shaft 11. By arranging the bearing 111, the friction between the rotating shaft 11 and the middle pipe 231 is reduced, the rotation of the rotating shaft 11 is more stable, and the service life of the equipment is prolonged.

[0157] In some embodiments, in order to further reduce the friction between the equipment, lubricating oil and a second sealing ring 112 are arranged in the middle pipe 231. The second sealing ring 112 is sleeved on the rotating shaft 11, and the second sealing ring 112 is arranged on the side of the bearing 111 close to the top plate 21. In this way, by arranging the second sealing ring 112, the lubricating oil in the bearing 111 can be prevented from leaking out, and the airflow can be further prevented from entering the middle pipe 231, dust and water are prevented, and the sealing performance of the centrifugal fan is improved.

[0158] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto, any change or replacement within the technical scope disclosed in the present application should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A centrifugal fan, characterized in that, The application relates to a fan, which comprises a shell, a rotating shaft and an impeller, the shell is provided with an air inlet and an air outlet, the impeller and the rotating shaft are arranged in a cavity surrounded by the shell, the air inlet and the air outlet are communicated with the cavity, the rotating shaft is rotationally connected with the shell, the impeller is connected with the rotating shaft, the impeller comprises a hub and blades fixedly connected with the hub, the middle camber line of the airfoil of the blade is curved in the opposite direction of the rotating direction of the impeller, the middle camber line of the airfoil of the blade comprises a leading edge end and a trailing edge end, the leading edge end is located at one end of the blade close to the rotating shaft, the trailing edge end is located at one end of the blade away from the rotating shaft, and the leading edge end is located in front of the trailing edge end in the rotating direction of the impeller. The air inlet angle of the blade is less than 60 degrees.

2. The centrifugal fan according to claim 1, characterized in that The air outlet angle of the blade is less than 90 degrees.

3. The centrifugal fan according to claim 1 or 2, characterized in that The surface of the hub towards the air inlet comprises a first region and a second region connected with each other, the first region is rotationally connected with the shell, the second region is arranged around the first region, the second region comprises opposite first and second side edges, the first side edge of the second region is connected with the first region, the second side edge of the second region is connected with the blade, and the distance between the first side edge of the second region and the air inlet is less than the distance between the second side edge of the second region and the air inlet.

4. The centrifugal fan according to any one of claims 1 to 3, characterized in that In the direction away from the air inlet, the second region is inclined from the first side edge to the second side edge in the radial direction of the impeller.

5. The centrifugal fan according to claim 4, wherein In the direction away from the air inlet, the surface of the hub towards the air inlet is inclined from the rotating shaft to the blade in the radial direction of the impeller.

6. The centrifugal fan according to any one of claims 1 to 3, characterized in that The leading edge of the blade comprises a first leading edge and a second leading edge connected in sequence, the second end of the first leading edge and the first end of the second leading edge are both connected with the hub, the first end of the first leading edge is close to the air inlet, and the distance between the first end of the first leading edge and the rotating shaft is greater than the distance between the second end of the first leading edge and the rotating shaft.

7. The centrifugal fan according to any one of claims 1 to 6, characterized in that In the direction away from the air inlet, the first leading edge is inclined towards the rotating shaft.

8. The centrifugal fan according to claim 7, characterized in that The second leading edge is parallel to the rotating shaft.

9. The centrifugal fan according to claim 7 or 8, characterized in that The distance between the first end of the second leading edge and the rotating shaft is greater than the distance between the second end of the second leading edge and the rotating shaft.

10. The centrifugal fan according to claim 7 or 8, characterized in that In the direction away from the air inlet, the second leading edge is inclined towards the rotating shaft.

11. The centrifugal fan according to claim 10, wherein The impeller comprises a plurality of blades arranged in the circumferential direction of the hub, an airflow channel is formed between two adjacent blades, an air inlet of the airflow channel is formed between the end portions of the two adjacent blades close to the rotating shaft, an air outlet of the airflow channel is formed between the end portions of the two adjacent blades away from the hub, and the cross section of the airflow channel gradually increases from the air inlet to the air outlet of the airflow channel.

12. The centrifugal fan according to any one of claims 1-11, characterized in that The middle camber line of the airfoil of the blade is a second-order Bezier curve, and the leading edge end and the trailing edge end are respectively a starting control point and a terminal control point of the second-order Bezier curve.

13. The centrifugal fan according to any one of claims 1-12, characterized in that ​ After the coordinate in the impeller polar coordinate system is converted into the coordinate in the blade rectangular coordinate system, the pole point in the impeller polar coordinate system is located on the rotation axis of the hub, the polar angle of the leading edge end in the impeller polar coordinate system is π / 2, the origin of the blade rectangular coordinate system is located at the leading edge end, the horizontal axis direction in the blade rectangular coordinate system is the same as the polar axis direction in the impeller polar coordinate system, and the positive direction of the vertical axis of the blade rectangular coordinate system is the direction in which the leading edge end points to the outside of the impeller in the radial direction of the impeller.

14. The centrifugal fan according to any one of claims 1-13, characterized in that The shell comprises a side wall, and oppositely arranged bottom plate and top plate, the rotation axis and the side wall are arranged between the top plate and the bottom plate, the side wall, the top plate and the bottom plate jointly enclose the cavity, the top plate is provided with an air inlet, and the side wall is provided with an air outlet.

15. The centrifugal fan of claim 14, wherein The centrifugal fan comprises a cross beam arranged in the air inlet and connected with the top plate, the cross beam comprises a connecting portion and a convex portion, the connecting portion is used for connecting the convex portion and the top plate, and the convex portion protrudes towards the bottom plate and is rotationally connected with the rotation axis.

16. The centrifugal fan of claim 15, wherein The convex portion and the connecting portion have the same thickness, and the convex portion is formed by bending the cross beam.

17. The centrifugal fan of claim 16, wherein The convex portion is provided with a ring-shaped member on the side thereof facing the bottom plate, and the rotation axis is rotationally connected with the ring-shaped member.

18. The centrifugal fan of claim 15, wherein, The thickness of the convex portion is greater than that of the connecting portion.

19. The centrifugal fan of claim 18, wherein The convex portion is provided with a limiting member on the side thereof close to the bottom plate, and the rotation axis is rotationally connected with the limiting member.

20. The centrifugal fan according to any one of claims 14-19, characterized in that The centrifugal fan further comprises a middle pipe sleeved outside the rotation axis, the rotation axis and the middle pipe are coaxially arranged, and the middle pipe and the bottom plate are integrally formed.

21. The centrifugal fan of claim 20, wherein The middle pipe comprises a first portion and a second portion connected with each other, the first portion is connected with the bottom plate, the second portion is arranged on the side of the first portion away from the bottom plate, and the side wall thickness of the first portion is greater than that of the second portion.

22. The centrifugal fan according to claim 20 or 21, characterized in that The centrifugal fan further comprises a motor shell, a motor and a first sealing ring, the motor shell is connected with the rotation axis, the motor shell is arranged between the hub and the motor, and the first sealing ring is sleeved on the middle pipe and partially arranged between the motor and the middle pipe.

23. The centrifugal fan of claim 22, wherein, The projection of the first sealing ring on the side wall is in the shape of an inverted T.

24. The centrifugal fan according to any one of claims 20-23, characterized in that The centrifugal fan further comprises a bearing and a second sealing ring, the bearing and the second sealing ring are arranged in the middle pipe and sleeved on the rotation axis, the bearing is rotationally connected with the rotation axis, and the second sealing ring is arranged on the side of the bearing close to the top plate.

25. An electronic device, comprising: The centrifugal fan is used for dissipating heat of a heat generating module.

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