CN220850064U

CN220850064U - Centrifugal fan, charging device and electronic equipment

Info

Publication number: CN220850064U
Application number: CN202321819489.6U
Authority: CN
Inventors: 李东方; 寇振中; 毛研伟
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2023-07-11
Filing date: 2023-07-11
Publication date: 2024-04-26
Anticipated expiration: 2033-07-11

Abstract

The application provides a centrifugal fan, a charging device and electronic equipment. The base wheel can rotate around the first axis relative to the shell, and the fan blades are arranged on the outer peripheral side of the base wheel at intervals and can rotate around the first axis under the drive of the base wheel. Each blade has a blade root facing the first axis and a blade edge facing away from the first axis. The plane where the perpendicular line between the blade root and the first axis is located is a first radial surface, the plane where the line between the blade root and the blade edge is located is a blade chord surface, an included angle is formed between the first radial surface and the blade chord surface, and the whole fan blades are bent towards the respective first radial surfaces. Each fan blade comprises a first fan blade section and a second fan blade section which are connected, and the curvature of the second fan blade section is larger than that of the first fan blade section. The centrifugal fan reduces noise on the premise of ensuring wind speed, and can realize high-efficiency heat dissipation and low-noise operation.

Description

Centrifugal fan, charging device and electronic equipment

Technical Field

The present application relates to the field of communications devices, and in particular, to a centrifugal fan, a charging device, and an electronic device.

Background

Centrifugal fans are widely used in heat dissipation systems for end products due to their high wind pressure. The rotation of the centrifugal fan generates noise, and the higher heat dissipation efficiency also brings about larger noise in terms of the operation characteristics of the centrifugal fan and the mechanism of noise generation. Therefore, the heat dissipation and noise of the centrifugal fan become a 'teeterboard' which is not easy to balance, and the characteristic of realizing high-efficiency heat dissipation and low-noise operation is a consistent demand of related end products.

Taking a vehicle-mounted wireless charging device as an example, consumers have increasingly demanded low noise in the vehicle, and besides the general problems of wind noise, road noise and the like, the pneumatic noise of a cooling fan and an air conditioning system of the vehicle-mounted wireless charging device becomes a key competition of various automobiles. The charging efficiency of the vehicle-mounted wireless charging device is always positively related to the heat dissipation requirement, and the higher the heat dissipation requirement is, the higher the rotation speed of the required centrifugal fan is, and the larger the noise is. In short, the noise tolerance of the centrifugal fan directly determines the efficiency of the system charging. The low-noise operation can be realized while the charging performance is met, so that better riding experience is brought to passengers.

Taking electronic devices such as notebook computers as an example, the noise problem of the cooling fan is one of the pain points which plague consumers. As the load of the electronic equipment system increases, the more heat is generated, the higher the required heat dissipation efficiency is, the greater the flow and the rotating speed of the centrifugal fan are, and the higher the noise is, so that the use experience of consumers is affected.

Therefore, in the prior art, when the rotating speed of the centrifugal fan is high, larger noise can be generated, and the high-efficiency heat dissipation and low-noise operation are difficult to be considered in a heat dissipation system of a related terminal product, so that the use experience of consumers is affected.

Disclosure of utility model

The embodiment of the application provides a centrifugal fan, a charging device and electronic equipment, which solve the problems that in the prior art, when the rotating speed of the centrifugal fan is high, larger noise is generated, high-efficiency heat dissipation and low-noise operation are difficult to be considered in a heat dissipation system of related terminal products, and the use experience of consumers is influenced.

The embodiment of the application provides a centrifugal fan, which comprises a shell, a base wheel and a plurality of fan blades. The shell is provided with an air inlet, an air outlet and an accommodating space, and the air inlet and the air outlet are communicated with the accommodating space. The base wheel is positioned in the accommodating space and can rotate relative to the shell around a first axis. The fan blades are arranged on the outer peripheral side of the base wheel at intervals and can rotate around the first axis under the drive of the base wheel.

Each of the plurality of blades has a blade root and a blade edge, the blade root faces the first axis, and the blade edge faces away from the first axis. In each fan blade, the plane where the perpendicular line between the blade root and the first axis is located is a first radial surface, the plane where the line between the blade root and the blade edge is located is a blade chord surface, an included angle is formed between the first radial surface and the blade chord surface, and the whole fan blade is bent towards the respective first radial surface.

Each fan blade comprises a first fan blade section and a second fan blade section which are connected, one end of the first fan blade section, which is far away from the second fan blade section, forms a blade root, one end of the second fan blade section, which is far away from the first fan blade section, forms a blade edge, and the curvature of the second fan blade section is larger than that of the first fan blade section.

The centrifugal fan provided by the application has the advantages that all the fan blades are driven by the base wheel to rotate. The first radial surface of each fan blade, that is, the plane where the blade root and the first axis of each fan blade are located together, can be understood as the normal plane of the base wheel at the blade root of each fan blade, and the chord surface of each fan blade, that is, the plane where the blade root and the blade edge are located together. An included angle is formed between the first radial surface and the chord surface of the blade, namely, the whole blade is inclined relative to the normal plane of the base wheel at the blade root of the blade. The whole fan blades are bent towards the first radial surfaces, namely, the whole fan blades are positioned on one side of the chord surfaces of the fan blades, which are far away from the first radial surfaces, and are bent towards the first radial surfaces. By adopting the structure, under the condition that parameters such as the size of the base wheel, the size of the shell, the distance between the fan blades and the inner wall of the shell and the like are certain, the whole length of the fan blades can be increased, so that the length of a flow channel between the fan blades is increased, the flow of air between the fan blades is buffered, the phenomena of agitation, secondary flow and flow separation of air flow are reduced, the pressure difference between the pressure surface and the suction surface of the fan blades can be reduced, the generation of vortex is inhibited from various aspects, the vortex is a main source of noise in the centrifugal fan, and the noise is also reduced by the reduction of the vortex.

Further, each fan blade is divided into a first fan blade section and a second fan blade section, the first fan blade section is closer to the first axis, the curvature of the second fan blade section is larger than that of the first fan blade section, and it can be understood that the first fan blade section is relatively gentle, and the second fan blade section is relatively curved. By adopting the structure, the first fan blade section plays the main roles of increasing the length of the fan blade, buffering air flow, inhibiting vortex and reducing noise, the second fan blade section with larger curvature can increase the back pressure at the position and improve wind speed, the phenomena of slow wind speed, insufficient power and the like caused by the integral inclination of the fan blade and the gentle curve of the first fan blade section are compensated, and the heat dissipation efficiency of the centrifugal fan is ensured, so that the best balance point among noise, wind pressure and efficiency can be achieved.

Therefore, the centrifugal fan provided by the embodiment of the application reduces noise on the premise of ensuring the wind speed, can realize high-efficiency heat dissipation and low-noise operation in the heat dissipation system of the related terminal product, and improves the use experience of consumers.

In some embodiments, the fan blade has an air inlet angle of 15 ° to 45 °. The air outlet angle of the fan blade is 90-120 degrees. The centrifugal fan in the range can achieve the best balance effect among noise, wind pressure and efficiency.

In some embodiments, the distance between two adjacent blades of the plurality of blades increases gradually from the blade root to the blade edge. By adopting the structure, the distances among the blade roots of the blades are relatively smaller, so that air can be effectively sucked into the air flow channels among the blades, and the wind pressure is improved. The distance between the blade edges is relatively large, the flow area of the outlet of the inter-blade flow channel (the airflow channel between adjacent blades) is increased, the airflow can be discharged out of the blades in time, the airflow is rapidly mixed after being discharged, the smoothness of the flow is ensured, the airflow interference in the centrifugal fan is reduced, and the efficiency is improved.

In some embodiments, the base wheel is rotatable in a first direction from the chord plane of each blade toward the first radial plane, i.e., the plurality of blades are rotated in a direction in which they are curved, thereby causing airflow between the blades.

In some embodiments, the housing includes a top wall, a bottom wall, and a side wall, the top wall and the side wall are disposed at intervals along an extending direction of the first axis, the side wall is connected between the top wall and the bottom wall, and the top wall, the bottom wall, and the side wall form a containing space around. The air inlet is positioned on the top wall, and the air outlet is positioned on the side wall.

With this structure, the flow path of air is: the air flow flows in the direction from the blade root to the blade edge in the inter-blade flow channels, is discharged from the blades at the outlet of each inter-blade flow channel, flows along the inner wall surface of the shell, is mixed and is discharged from the air outlet of the side wall of the shell.

In some embodiments, the top wall is provided with a circular through hole, which constitutes the air inlet, the first axis passing through the centre of the air inlet. The surface of the connecting point of the first fan blade section and the second fan blade section of each fan blade is a first ring surface, and the first ring surface is overlapped with the edge of the air inlet along the extending direction of the first axis. Namely, the connection point of the first fan blade section and the second fan blade section on each fan blade corresponds to the position and the size of the air inlet, and the centrifugal fan can achieve the best balance effect among noise, wind pressure and efficiency through the design.

In some embodiments, each fan blade has a first end face and a second end face opposite to each other along an extension direction of the first axis, and the first end face and the second end face are disposed in parallel. The heights of the blades in the direction from the blade root to the blade edge along the first axis are kept consistent, the contact area of air and the blades is increased, the wind speed is improved, and the heat dissipation efficiency of the centrifugal fan is improved.

In some embodiments, each blade extends along a Bezier curve from the blade root to the blade edge.

The embodiment of the application also provides a charging device which comprises the centrifugal fan provided by any embodiment. The charging device has higher charging efficiency and lower heat dissipation noise, and the use experience is better.

In some embodiments, the charging device further comprises an air duct, the air duct has an air inlet end and an air outlet end, the centrifugal fan is located in the air duct, and an air inlet of the centrifugal fan is opposite to the air inlet end of the air duct, and air flowing out from an air outlet of the centrifugal fan can flow to the air outlet end of the air duct along an extending direction of the air duct. When the charging device charges the electronic equipment, the electronic equipment is placed at the air outlet end of the air duct.

By adopting the structure, the centrifugal fan drives the air flow in the air duct, and the electronic equipment is opposite to the air outlet end of the air duct, so that the air flow flowing out of the air outlet end can flow through the electronic equipment to dissipate heat of the electronic equipment.

The embodiment of the application also provides electronic equipment, which comprises the centrifugal fan provided by any embodiment. The electronic equipment cooling system has high cooling efficiency, can timely discharge heat, can bear higher load, has lower operation noise and has better use experience.

In some embodiments, the electronic device further comprises a device housing and a heating device, wherein the device housing is provided with a containing cavity, and a vent for communicating the containing cavity with the outside is arranged on the device housing, and the centrifugal fan and the heating device are positioned in the containing cavity.

By adopting the structure, the centrifugal fan can suck the outside air through the ventilation opening on the equipment shell to radiate heat for the heating device.

Drawings

FIG. 1 is a sound pressure level versus frequency plot of a centrifugal fan;

FIG. 2 is a schematic diagram of a centrifugal fan in some embodiments;

FIG. 3 is a flow field simulation of the centrifugal fan of FIG. 2;

fig. 4 is a schematic structural diagram of a charging device according to an embodiment of the present application;

FIG. 5 is a schematic diagram of an electronic device according to an embodiment of the present application;

FIG. 6 is a cross-sectional view taken along the direction A-A in FIG. 5;

FIG. 7 is a schematic perspective view of a centrifugal fan according to an embodiment of the application;

FIG. 8 is an exploded view of a centrifugal fan according to an embodiment of the present application;

FIG. 9 is a schematic perspective view of a base wheel and blades of a centrifugal fan according to an embodiment of the application;

FIG. 10 is a schematic plan view of a base wheel and blades in a centrifugal fan according to an embodiment of the application;

FIG. 11 is a schematic view of the inlet and outlet angles of the blades of a centrifugal fan according to an embodiment of the application;

FIG. 12 is a diagram showing a comparison of a centrifugal fan and the fan blade structure of the centrifugal fan shown in FIG. 2 according to an embodiment of the present application;

FIG. 13 is a schematic view showing the cooperation of the housing, blades, and base wheel in a centrifugal fan according to an embodiment of the application;

FIG. 14 is a flow field simulation diagram of a centrifugal fan according to an embodiment of the application;

fig. 15 is a sound pressure level versus rotational speed graph of a centrifugal fan according to an embodiment of the application and the centrifugal fan of fig. 2.

Reference numerals illustrate:

the prior art comprises the following steps:

100': a centrifugal fan;

1': a housing; 2': a base wheel;

3': a fan blade; 31': blade root; 32': leaf edges;

33': a suction surface; 34': a pressure surface;

4': inter-leaf flow passages; o': an axis.

The application comprises the following steps:

100: a centrifugal fan;

1: a housing; 10: an accommodation space; 11: an air inlet; 12: an air outlet;

13: a top wall; 14: a bottom wall;

15: a sidewall; 151: a flow guiding surface; 1511: a cambered surface; 1512: a plane;

152: a split surface; 153: an outlet diffuser surface;

2: a base wheel; 21: a main body portion; 22: a wheel disc;

3: a fan blade; 31: blade root; 32: leaf edges; 33: a first fan blade section; 34: a second fan blade section;

35: a pressure surface; 36: a suction surface; 37: a first end face; 38: a second end face;

41: inter-leaf flow passages; 42: a rotation field;

200: a charging device;

51: a housing; 510: a housing chamber; 52: a charging circuit;

53: an air duct; 531: an air inlet end; 532: an air outlet end; 54: an external flow channel;

300: an electronic device;

6: an equipment housing; 61: a first housing; 62: a second housing;

620: a receiving chamber; 621: a first vent; 622: a second vent;

623: a top plate; 624: a bottom plate; 625: a sidewall;

71: a display; 72: a keyboard; 73: a touch panel; 8: a host;

o: a first axis;

p1: a first radial surface; p2: a chord plane;

p3: a first circumferential surface; p4: a second circumferential surface; p5: a first annulus;

alpha: an air inlet angle; beta: an air outlet angle;

And z: the thickness direction of the second shell; x: a first direction.

Detailed Description

Further advantages and effects of the present application will become apparent to those skilled in the art from the disclosure of the present specification, by describing the embodiments of the present application with specific examples. While the description of the application will be presented in connection with certain embodiments, it is not intended to limit the features of this application to only this embodiment. Rather, the purpose of the present application is to cover other alternatives or modifications, which may be extended by the claims based on the application. The following description contains many specific details for the purpose of providing a thorough understanding of the present application. The application may be practiced without these specific details. Furthermore, some specific details are omitted from the description in order to avoid obscuring the application. It should be noted that, without conflict, the embodiments of the present application and features of the embodiments may be combined with each other.

It should be noted that in this specification, like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures.

In the description of the present application, it should be noted that the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present application. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present application, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present application will be understood in specific cases by those of ordinary skill in the art.

In the description of the present application, it should be understood that "electrically connected" in the present application may be understood that components are in physical contact and electrically conductive; it is also understood that the various components in the circuit configuration are connected by physical lines, such as printed circuit board (printed circuit board, PCB) copper foil or wires, that transmit electrical signals.

In the description of the present application, it should be noted that the mutual perpendicularity in the present application is not absolute perpendicularity, and that the approximate perpendicularity (for example, the included angle between two structural features is 89.9 °) due to the machining error and the assembly error is also within the scope of the mutual perpendicularity in the present application. The mutual parallelism in the present application is not absolute, and approximate parallelism (e.g., an angle of 0.1 ° between two structural features) due to machining errors and assembly errors is also within the scope of the mutual parallelism in the present application. The present application is not particularly limited thereto.

For the purpose of making the objects, technical solutions and advantages of the present application more apparent, embodiments of the present application will be described in further detail below with reference to the accompanying drawings.

Taking a vehicle-mounted wireless charging device as an example, consumer demands for low noise in a vehicle are increasing, and besides the problems of universality such as wind noise, road noise and the like, the cooling fan of the vehicle-mounted wireless charging device and the pneumatic noise of an air conditioning system become key competition of various automobiles. The charging efficiency of the vehicle-mounted wireless charging device is always positively related to the heat dissipation requirement, and the higher the heat dissipation requirement is, the higher the rotation speed of the required centrifugal fan is, and the larger the noise is. In short, the noise tolerance of the centrifugal fan directly determines the efficiency of the system charging. The low-noise operation can be realized while the charging performance is met, so that better riding experience is brought to passengers.

Taking electronic devices such as notebook computers as an example, the noise problem of the cooling fan is one of the pain points which plague consumers. As the load of the electronic equipment system increases, the more heat is generated, the higher the required heat dissipation efficiency is, the greater the flow and the rotating speed of the centrifugal fan are, and the higher the noise is, so that the use experience of consumers is affected. The following describes the noise problem caused by the centrifugal fan in the notebook computer in detail by combining with a sound pressure level-frequency test curve of the centrifugal fan in the notebook computer.

Referring to fig. 1, fig. 1 is a sound pressure level-frequency diagram of a centrifugal fan.

As shown in fig. 1, the abscissa in fig. 1 represents the frequency (Hz) of noise, and the ordinate represents the sound pressure level (dBA), and the higher the sound pressure level, the greater the loudness of noise. The darker curve (i.e., the lower curve) represents the curve at a fan speed of 4500rpm and the lighter curve (i.e., the upper curve) represents the curve at a fan speed of 5000 rpm. As can be seen from fig. 1, the 5000rpm speed curve is located entirely above the 4500rpm speed curve, and it can be inferred that the higher the speed of the fan, i.e., the higher the heat dissipation efficiency, the greater the noise loudness in each frequency range that it generates, which is contrary to the consumer's need for high heat dissipation efficiency and low noise operation of the centrifugal fan. Also, at certain frequencies, the sound pressure level has abrupt peaks (two points B, C are labeled in fig. 1 as an example) where the noise suddenly increases and the noise perceived by the human ear is more sharp and harsher. Therefore, the noise generated by the cooling fan of the notebook computer does affect the use experience of consumers, and the efficient cooling and the low-noise operation are not compatible.

In order to more clearly show the working mode of the centrifugal fan and the mechanism of noise generation, the following analysis is performed by combining the structure of the centrifugal fan and the result of sound field simulation thereof.

Referring to fig. 2-3, fig. 2 is a schematic structural diagram of a centrifugal fan according to some embodiments; fig. 3 is a flow field simulation diagram of the centrifugal fan of fig. 2.

As shown in fig. 2-3, the centrifugal fan 100 'includes a casing 1', a base wheel 2 'mounted in the casing 1', and a plurality of blades 3 ', wherein the blades 3' are distributed on the outer peripheral side of the base wheel 2 'in a ring-shaped array, and can rotate around an axis o' under the driving of the base wheel 2 '(the direction perpendicular to the paper surface in fig. 2 is the extending direction of the axis o'). Each blade 3 ' includes a blade root 31 ' and a blade edge 32 ', the blade root 31 ' being arranged perpendicularly to the base wheel 2 ', the blade edge 32 ' being tilted forward relative to the base wheel 2 '.

Wherein the blade root 31 'is perpendicular to the base wheel 2' is understood as: in each blade 3 ', a tangential plane m ' of the blade 3 ' is defined at the blade root 31 ', which extends in the radial direction of the base wheel 2 ', i.e. the axis o ' lies in the tangential plane m ', which can be regarded as the normal plane of the base wheel 2 ' at the blade root 31 '. The rake of the rim 32 'relative to the base wheel 2' can be understood as: the edge 32 ' of each blade 3 ' is curved in a direction away from its root normal plane (tangential plane m '), and the blade 3 ' is located entirely on the side of the respective root normal plane facing the direction of rotation of the blade 3 '. For example, in fig. 2, the centrifugal fan 100 ' rotates counterclockwise when operated, and the rim 32 ' of each fan blade 3 ' is curved counterclockwise as a whole. With this structure, the difference in wind pressure between the suction surface 33 ' and the pressure surface 34 ' of each fan blade 3 ' is large, so that the fan blade has strong suction force, and can effectively drive air to flow rapidly. However, this structure correspondingly increases the fluctuation of the air flow, and generates a large noise.

When the blades 3 ' rotate, the air flow passes through the inter-blade flow channels 4 ' between the adjacent blades 3 '. As can be seen from fig. 3, the airflow generates unsteady fluctuations such as airflow turbulence and secondary flow at abrupt flow channel positions, for example, at the air inlet (at the blade root 31 ') and the air outlet (at the blade edge 32 ') of the inter-blade flow channel 4 ', and has obvious flow separation phenomena, which can be embodied at the vortex positions selected by the dashed line boxes in fig. 3. Therefore, the centrifugal fan 100' generates a large aerodynamic noise when rotating.

Therefore, in some schemes, when the rotation speed of the centrifugal fan is high, larger noise can be generated, and in a heat dissipation system of a related terminal product, both high-efficiency heat dissipation and low-noise operation are difficult to be considered, so that the use experience of consumers is affected.

Therefore, the inventor systematically analyzes the structure and the working principle of the centrifugal fan through various methods such as simulation test, flow field sound field calculation, model correction and experimental comparison, finds that the shape of the fan blade has quite important influence on the working efficiency and noise of the centrifugal fan, and improves the shape of the fan blade according to the results of the experiment and the analysis. The application provides a centrifugal fan, which realizes the balance among noise, wind pressure and heat dissipation efficiency by improving the shape of fan blades, reduces noise on the premise of ensuring wind speed, can realize high-efficiency heat dissipation and low-noise operation in a heat dissipation system of related terminal products, and improves the use experience of consumers.

The centrifugal fan provided by the embodiment of the application can be applied to a charging device, wherein the charging device comprises, but is not limited to, a wired charging device, a wireless charging device, a new energy charging device, a solar charging device and the like. An application scenario of the centrifugal fan in the charging device is exemplarily described below taking an in-vehicle wireless charging device as an example.

Referring to fig. 4, fig. 4 is a schematic structural diagram of a charging device according to an embodiment of the application.

As shown in fig. 4, an embodiment of the present application provides a charging device 200, where the charging device 200 may include a housing 51 and a charging circuit 52, the housing 51 has a housing cavity 510 therein, and the charging circuit 52 is located in the housing cavity 510. The housing 51 may serve as a placement plate for an electronic device (e.g., a cell phone, shown in phantom). In an exemplary scenario, when the charging apparatus 200 charges an electronic device, the electronic device is placed on the housing 51, and the charging circuit 52 automatically senses a placement position of the electronic device, and if the placement position is correct, the charging module may be triggered to charge the electronic device. In one embodiment, the charging device 200 may further include a data line (not shown in the figure), where one end of the data line is connected to the charging circuit 52, and the other end is connected to an in-vehicle power supply system, so as to transmit in-vehicle current to the charging device 200 to supply power to the electronic device.

The specific configuration of the charging circuit 52 is not limited herein. In one example scenario, the charging circuit 52 may include a circuit board, which may be a PCBA board or the like, on which a plurality of electronic components are mounted. The kind of the electronic component is not limited, and may include, for example, a coil, a capacitor, an inductor, a chip, a driver, a step-down circuit, a shield layer, and the like. In addition to the charging circuit 52, the housing 510 may include components such as a battery system and a support fixture, which are not limited in this regard. The centrifugal fan 100 is also located in the accommodating cavity 510 for dissipating heat from the electronic device.

As shown in fig. 4, in one embodiment, the charging device 200 further includes an air duct 53, and the centrifugal fan 100 is located within the air duct 53. The specific form of the air duct 53 is not limited. In one embodiment, housing 51 of charging device 200 surrounds air chute 53.

Further, the air duct 53 has an air inlet end 531 and an air outlet end 532, and the air inlet end 531 and the air outlet end 532 are both communicated with the outside, and air can flow into the air duct 53 from the air inlet end 531 and flow out from the air outlet end 532. The air inlet 11 of the centrifugal fan 100 is disposed opposite to the air inlet end 531 of the air duct 53, and air flowing out from the air outlet 12 of the centrifugal fan 100 can flow toward the air outlet end 532 of the air duct 53 in the extending direction of the air duct 53. When the charging device 200 charges the electronic device, the electronic device is located at the air outlet end 532 of the air duct 53. The centrifugal fan 100 rotates to suck air from the air inlet end 531 of the air duct 53 to drive the air flow in the air duct 53, and the electronic device faces the air outlet end 532 of the air duct 53, so that the air flow flowing out of the air outlet end 532 can flow through the electronic device to dissipate heat of the electronic device.

In one embodiment, when the electronic device is placed on the housing 51, an external flow channel 54 is formed between the housing 51 and the electronic device, and the air flow blown out from the air outlet end 532 of the air duct 53 can flow along the external surface of the electronic device in the external flow channel 54, so as to dissipate heat of the electronic device as a whole. The specific form of the external flow channel 54 is not limited, for example, grooves may be formed on the housing 51 of the charging device 200, and the electronic device may be attached to the grooves to form the external flow channel 54. Alternatively, some protrusions may be provided on the housing 51 of the charging device 200, and the electronic device may be placed on the protrusions during charging, so that the gap between the electronic device and the housing 51 forms the external flow path 54. In one embodiment, the external flow channel 54 extends along the length direction of the electronic device (the left-right direction in fig. 4 may be the length direction of the electronic device), so as to increase the contact area between the air flow and the electronic device and improve the heat dissipation effect. In other alternative embodiments, the external flow channel 54 may also extend along the width of the electronic device, as the application is not limited in this regard.

The configuration illustrated in the embodiment of the present application does not constitute a specific limitation of the charging device 200. In other embodiments, charging device 200 may also include more or fewer components than shown, such as interfaces, transformers, control panels, chips, lights, etc.

The centrifugal fan provided by the embodiment of the application can be applied to electronic equipment, and the electronic equipment can comprise, but is not limited to, common terminals such as notebook computers, mobile phones, tablet computers, charger, vehicle-mounted equipment, mobile WiFi and the like. The application of the centrifugal fan will be described below using a notebook computer as an example.

Referring to fig. 5-6, fig. 5 is a schematic structural diagram of an electronic device according to an embodiment of the application; fig. 6 is a cross-sectional view taken along the direction A-A in fig. 5.

As shown in fig. 5, the electronic device 300 includes a device housing 6, where the device housing 6 includes a first housing 61 and a second housing 62 that can rotate relatively, and in some examples, the housing formed by the first housing 61 and the second housing 62 may be a rear cover, a middle frame of the electronic device 300 or other frame of the electronic device 300 that serves as a support for mounting, which the present application is not limited in this respect.

The first housing 61 is provided with a display 71 for displaying an image, and the second housing 62 is provided with input devices such as a keyboard 72 and a touch panel 73. As shown in fig. 6, the second housing 62 has a housing chamber 620 therein, and can mount electronic devices such as the host computer 8. The specific form of the host 8 is not limited, and may be, for example, an integrated system including a memory, a power supply, an optical drive, a processor, and other processing modules, and may be used to arrange circuits, implement multiple functions of running an operating system, processing various data, running an application program, controlling and connecting to the processor, and the like. The keyboard 72 and the touch pad 73 are electrically connected with the host computer 8, the host computer 8 can acquire the operation information of a user through the keyboard 72 and the touch pad 73, and the processor analyzes and computes and then sends out corresponding instructions. When the host 8 is provided with a plurality of heating devices (such as a radio frequency chip and a charging chip) and the host 8 is operated, the heating devices generate heat, if the heat cannot be timely discharged, the electronic equipment 300 is too high in temperature and can damage internal elements, and the operation efficiency is also affected by the overheating of the host 8, so that heat dissipation is required for the heating devices on the host 8.

As shown in fig. 6, the electronic device 300 further includes a centrifugal fan 100, where the centrifugal fan 100 is located in the accommodating cavity 620 of the second housing 62 to dissipate heat from the host 8. In one embodiment, the second housing 62 is provided with a plurality of ventilation openings, which communicate the accommodating chamber 620 with the outside, and the centrifugal fan 100 sucks and exhausts air through the ventilation openings. The specific location and number of vents is not limited. In one embodiment, the second housing 62 is provided with a first ventilation opening 621 and a second ventilation opening 622, the first ventilation opening 621 is spaced from the second ventilation opening 622, one of the first ventilation opening 621 and the second ventilation opening 622 is used for allowing outside air to flow in (i.e. as an air inlet), and the other is used for air to flow out (i.e. as an air outlet), and the positions and effects of the first ventilation opening 621 and the second ventilation opening 622 are not limited in the application. In one embodiment, the first ventilation hole 621 is used as an air inlet, and the second ventilation hole 622 is used as an air outlet.

It will be appreciated by those skilled in the art that the specific shape and location of the first ventilation openings 621 and the second ventilation openings 622 may be designed according to the needs, and the present embodiment is not limited thereto. In one embodiment, the second housing 62 includes a top plate 623 and a bottom plate 624 disposed opposite to each other in a thickness direction z of the second housing, and the top plate 623 and the bottom plate 624 are connected by a side wall 625. Wherein the top plate 623 may serve as a front surface of the second housing 62, the top plate 623 facing the display 71 when the first housing 61 and the second housing 62 of the electronic device 300 are closed to each other. The keyboard 72 and the touch pad 73 are each provided in the top plate 623 in the thickness direction z of the second housing. The bottom plate 624 may serve as a back surface of the second housing 62, and the electronic device 300 may be placed on a desktop with the bottom plate 624 in contact with the desktop when the electronic device 300 is in use. The side wall 625 may not only support the top plate 623 and the bottom plate 624, but may also be provided with a plurality of interfaces and functional keys, such as earphone interfaces, charging interfaces, power keys, etc. In one embodiment, the first vent 621 is located on the floor 624 and the second vent 622 is located on the side wall 625. The air inlet 11 of the centrifugal fan 100 is opposite to the first ventilation hole 621, and the air outlet 12 is opposite to the main board. When the centrifugal fan 100 is operated, air is sucked through the first ventilation opening 621, and air discharged from the air outlet 12 of the centrifugal fan 100 flows through the heat generating devices on the main board, exchanges heat with the heat generating devices, and air having absorbed heat of the heat generating devices is discharged through the second ventilation opening 622, thereby cooling and radiating the heat of the heat generating devices.

Those skilled in the art will appreciate that the manner in which the electronic device 300 dissipates heat is not limited to the examples described above, but may be designed as desired. For example, gaps between keys on the keyboard 72 may also be used as ventilation openings to realize convective heat transfer from the keys of the keyboard 72. A cooling system may be disposed in the second housing 62, and may include a plurality of centrifugal fans 100 and water cooling pipes, and heat may be dissipated from the main board by the cooperation between the plurality of centrifugal fans 100 and the water cooling pipes, which is not shown here.

It should be noted that the structure illustrated in the embodiment of the present application does not constitute a specific limitation of the electronic device 300. In other embodiments, electronic device 300 may include more or fewer components than shown, for example, may also include cameras, speakers, and the like.

The structure and operation of the centrifugal fan 100 according to the embodiment of the present application will be described with reference to the accompanying drawings.

Referring to fig. 7-12, fig. 7 is a schematic perspective view of a centrifugal fan according to an embodiment of the application; FIG. 8 is an exploded view of a centrifugal fan according to an embodiment of the present application; FIG. 9 is a schematic perspective view of a base wheel and blades of a centrifugal fan according to an embodiment of the application; FIG. 10 is a schematic plan view of a base wheel and blades in a centrifugal fan according to an embodiment of the application; FIG. 11 is a schematic view of the inlet and outlet angles of the blades of a centrifugal fan according to an embodiment of the application; fig. 12 is a diagram showing a comparison of a centrifugal fan according to an embodiment of the application and a blade structure of the centrifugal fan in fig. 2.

As shown in fig. 7 to 12, the centrifugal fan 100 includes a housing 1, a base wheel 2, and a plurality of blades 3. The housing 1 has an air inlet 11, an air outlet 12, and an accommodation space 10, and both the air inlet 11 and the air outlet 12 communicate with the accommodation space 10. The base wheel 2 is located in the accommodation space 10 and is rotatable relative to the housing 1 about a first axis o. The fan blades 3 are arranged at intervals on the outer peripheral side of the base wheel 2 and can rotate around the first axis o under the drive of the base wheel 2.

For convenience of description, the extending direction of the first axis o will be referred to as an axis direction hereinafter. In one embodiment, the base wheel 2 has a cylindrical structure extending in the axial direction, and the first axis o passes through the center E of the base wheel 2 on a plane perpendicular to the axial direction (i.e., the view of fig. 10), and the plurality of blades 3 are distributed on the outer peripheral side of the base wheel 2 in an annular array with the center E of the base wheel 2 as the center. The specific number of the fan blades 3 is not limited, and can be designed according to requirements.

Further, each blade 3 has a blade root 31 and a blade edge 32, the blade root 31 facing the first axis o and the blade edge 32 facing away from the first axis o. Or it can be appreciated that the root 31 of each blade 3 is concentrated towards the centre E of the base wheel 2 and that the rim 32 diverges away from the centre E of the base wheel 2. In each fan blade 3, a plane in which a perpendicular line between the blade root 31 and the first axis o is located is a first radial plane P1, a plane in which a line between the blade root 31 and the blade edge 32 is located is a blade chord plane P2, an included angle is formed between the first radial plane P1 and the blade chord plane P2, and each fan blade 3 is entirely bent toward the respective first radial plane P1. Each blade 3 comprises a first blade section 33 and a second blade section 34 which are connected, wherein one end of the first blade section 33 far away from the second blade section 34 forms a blade root 31, one end of the second blade section 34 far away from the first blade section 33 forms a blade edge 32, and the curvature of the second blade section 34 is larger than that of the first blade section 33.

In the centrifugal fan 100 provided by the application, all the fan blades 3 are driven to rotate by the base wheel 2. The first radial plane P1 of each fan blade 3, that is, the plane where the blade root 31 of each fan blade 3 and the first axis o are located together, is understood as the normal plane of the base wheel 2 at the blade root 31 of each fan blade 3, and the chord plane P2, that is, the plane where the blade root 31 and the blade edge 32 are located together in each fan blade 3. It should be understood that, since the blade 3 has a certain thickness, the blade root 31 and the blade edge 32 are actually planes extending in the axial direction, and the thickness of the blade 3 may be ignored during the theoretical analysis, the blade root 31 and the blade edge 32 may be regarded as line segments extending in the axial direction. In the view of fig. 10-12, the blade root 31 and the blade edge 32 may particularly be represented as points, i.e. the blade root 31 is represented by point M and the blade edge 32 is represented by point N. The plane E, M in fig. 10-12 is the first radial plane P1, M, N is the chord plane P2. The first radial plane P1 forms an angle with the chord plane P2, i.e. the whole blade 3 is inclined relative to the normal plane (first radial plane P1) of the base wheel 2 at the root 31 of the blade 3. Each fan blade 3 is curved toward the first radial surface P1, that is, each fan blade 3 is located on the side of the chord surface P2 of the fan blade 3 away from the first radial surface P1, and is curved toward the first radial surface P1.

In one embodiment, the base wheel 2 is rotatable in a first direction x, which is a direction of rotation from the chord plane P2 of each fan blade 3 towards the first radial plane P1, i.e. the plurality of fan blades 3 are rotated towards their respective bending directions. In the view of fig. 10, the blades 3 are rotated in the counterclockwise direction as a whole, thereby driving the air flow between the blades 3.

As shown in fig. 12, the fan blades 3 'of the centrifugal fan 100' in fig. 2 are shown by dotted lines, and the fan blades 3 of the centrifugal fan 100 in the embodiment of the present application are shown by solid lines, and it is understood that, in comparison, in the case that the remaining relevant design parameters are unchanged (such as the size of the base wheel, the size of the housing, the space between the fan blades and the inner wall of the housing, etc. are fixed), the overall length of the fan blades 3 in the embodiment of the present application is longer, so that the length of the inter-blade flow channel 41 (i.e., the airflow channel between adjacent fan blades 3) is increased, the flow of air between the fan blades 3 is buffered, so that the turbulence, the secondary flow and the flow separation phenomenon of the airflow are reduced, the generation of vortex is suppressed, and the vortex is the main source of noise in the centrifugal fan 100, and the reduction of the vortex is also likely to reduce the noise.

Each fan blade 3 has a pressure surface 35 and a suction surface 36, the pressure surface 35 and the suction surface 36 are both connected to the blade root 31 and the blade edge 32, the pressure surface 35 is a curved surface of each fan blade 3 facing the first radial surface P1 thereof along the first direction x, and the suction surface 36 is a curved surface facing away from the first radial surface P1 thereof. The pressure of the air flow on the side where the pressure surface 35 is located is greater than the pressure of the air flow on the side where the suction surface 36 is located, so that a low-pressure area is formed in the area, close to the suction surface 36 of the fan blade 3, of each inter-blade flow channel 41, and the larger the pressure difference between the pressure surface 35 and the suction surface 36 is, the larger the low-pressure area is, the more vortex is easy to generate. According to the structure of the fan blade 3, the pressure difference between the pressure surface 35 and the suction surface 36 of the fan blade 3 can be reduced under the condition that other related design parameters and the fan rotating speed are certain, so that vortex generation is further suppressed, and noise is reduced. In order to fully embody the noise reduction effect of the centrifugal fan 100 according to the embodiment of the present application, flow field simulation and experimental tests are performed on the centrifugal fan 100 as well, which will be specifically shown later.

Further, each fan blade 3 is divided into a first fan blade segment 33 and a second fan blade segment 34, the first fan blade segment 33 is closer to the first axis o, the curvature of the second fan blade segment 34 is larger than that of the first fan blade segment 33, and it is understood that the first fan blade segment 33 is relatively gentle, and the second fan blade segment 34 is relatively curved. With such a structure, the first blade section 33 plays a main role in increasing the length of the blade 3, buffering the airflow, suppressing the vortex and reducing the noise, while the second blade section 34 with larger curvature can increase the back pressure at the position and increase the wind speed, make up for the phenomena of slow wind speed, insufficient power and the like caused by the whole inclination of the blade 3 and the gentle curve of the first blade section 33, ensure the heat dissipation efficiency of the centrifugal fan 100, thereby achieving the optimal balance point among the noise, the wind pressure and the efficiency.

Therefore, the centrifugal fan 100 provided by the embodiment of the application reduces noise on the premise of ensuring wind speed, and can realize high-efficiency heat dissipation and low-noise operation in the heat dissipation system of the related terminal products, thereby improving the use experience of consumers.

Those skilled in the art will appreciate that the particular shape of the fan blade 3 is not limited. As shown in fig. 11, in one embodiment, the fan blade 3 has an inlet angle α and an outlet angle β. The intake angle α is the angle between the airflow velocity vector at the inlet of the inter-vane flow channel 41 and the frontal line, and the geometry thereof is expressed as follows: the ring surface where the blade roots 31 of all the blades 3 are located is denoted as a first circumferential surface P3, and the first circumferential surface P3 is a track swept by the blade roots 31 of all the blades 3 when the centrifugal fan 100 rotates. The ring surface where the edges 32 of all the blades 3 are located is denoted as a second circumferential surface P4, and the second circumferential surface P4 is a track swept by the edges of all the blades 3 when the centrifugal fan 100 rotates. In each fan blade 3, the blade root 31 is a tangential plane of the first circumferential plane P3 and a tangential plane of the fan blade 3, and an included angle between the tangential plane of the first circumferential plane P3 and the tangential plane of the fan blade 3 is an air inlet angle α of the fan blade 3.

The air outlet angle beta of the fan blade 3 is the included angle between the air flow velocity vector at the outlet of the inter-blade flow channel 41 and the frontal line, and the geometrical expression is as follows: the blade passing edge 32 is made into a tangential plane of the second circumferential surface P4 and a tangential plane of the fan blade 3, and an included angle between the tangential plane of the second circumferential surface P4 and the tangential plane of the fan blade 3 is an air outlet angle β of the fan blade 3.

In one embodiment, the intake angle α is 15 ° to 45 °, for example, 15 °, 20 °, 30 °, 32 °, or the like. The air outlet angle β of the fan blade 3 is 90 ° to 120 °, for example, 90 °, 95 °, 110 °, 118 °, and the like. The centrifugal fan 100 in this range can achieve an optimal balance effect among noise, wind pressure, and efficiency. In other alternative embodiments, the inlet angle α may be less than 15 ° to or greater than 45 °, and the outlet angle β may be less than 90 ° or greater than 120 °. Specifically, in one embodiment, from the blade root 31 to the blade edge 32, each blade 3 extends along a bezier curve, and the shape of the blade 3 can be calculated from the inlet angle α and the outlet angle β of the blade 3.

As shown in fig. 9-11, in one embodiment, the distance between two adjacent blades 3 increases gradually from the blade root 31 to the blade edge 32. With this structure, the distance between the blade roots 31 of the adjacent blades 3 is relatively small, so that the wind pressure can be raised, and the air can be effectively sucked into the inter-blade flow passages 41. The distance between the vane edges 32 is relatively large, increasing the flow area S of the outlet of the inter-vane flow path 41. The outlet flow area S of the inter-blade flow channel 41 is the product of the height h of the fan blade 3 along the axial direction and the distance d between the adjacent blade edges 32, that is, s=h×d, the larger the distance d between the blade edges 32 is, the larger the outlet flow area S is, so that the air flow can be discharged out of the fan blade 3 in time, and the air flow can be quickly mixed after being discharged, so that the smoothness of the flow is ensured, the air flow interference in the centrifugal fan 100 is reduced, and the heat dissipation efficiency is improved.

As shown in fig. 9, in one embodiment, each fan blade 3 has a first end surface 37 and a second end surface 38 that are opposite to each other in the axial direction, and the first end surface 37 is disposed in parallel with the second end surface 38. That is, the height h of each blade 3 along the axial direction from the blade root 31 to the blade edge 32 is kept uniform, the contact area between the air and the blade 3 is increased, the wind speed is increased, and the heat dissipation efficiency of the centrifugal fan 100 is improved.

It will be appreciated by those skilled in the art that the structure of the base wheel 2 and the manner in which the blades 3 cooperate with the base wheel 2 are not limited. As shown in fig. 9 to 10, in one embodiment, the base wheel 2 includes a body portion 21 and a wheel disc 22 that are connected, and the wheel disc 22 is located on one side of the body portion 21 in the axial direction. The wheel disc 22 and the main body 21 are both in a cylindrical structure, the diameter of the main body 21 is smaller than that of the wheel disc 22, each fan blade 3 is mounted on the wheel disc 22, and each fan blade 3 and the main body 21 are arranged at intervals. The main body 21 may be used to house a circuit of the centrifugal fan 100, for example, a driving system such as a hall device, a coil, a motor, etc. may be disposed in the main body, and the wheel disc 22 is used to fix the base wheel 2 and the fan blades 3 on the casing 1 of the centrifugal fan 100, and drive the fan blades 3 to rotate under the driving of the driving system.

Those skilled in the art will appreciate that the positional relationship of the fan blade 3 and the wheel disc 22 is not limited. In one embodiment, the rim 32 of each fan blade 3 is located on the outer edge of the wheel disc 22. Or it will be appreciated that the projection of the fan blade 3 onto the disk 22 in the axial direction is entirely coincident with the disk 22 and that the blade edge 32 of the fan blade 3 overlaps the outer edge of the disk 22. In other alternative embodiments, the edge 32 of each fan blade 3 may not be located on the outer edge of the disk 22, for example, may protrude from the outer edge of the disk 22, etc., and may be designed according to the needs.

It will be appreciated by those skilled in the art that the specific structure of the housing 1 is not limited. The structures that can be employed by the housing 1, and the direction of the air flow within the housing 1, are illustrated below in connection with the accompanying drawings.

Referring to fig. 13, fig. 13 is a schematic diagram illustrating the cooperation of a housing, blades and a base wheel in a centrifugal fan according to an embodiment of the application.

As shown in fig. 8 to 9 and 13, in one embodiment, the housing 1 includes a top wall 13, a bottom wall 14, and a side wall 15, the top wall 13 and the side wall 15 are disposed at intervals in the axial direction, the side wall 15 is connected between the top wall 13 and the bottom wall 14, and the top wall 13, the bottom wall 14, and the side wall 15 surround to form the accommodating space 10. The air inlet 11 is located on the top wall 13 and the air outlet 12 is located on the side wall 15. The specific shape and size of the air inlet 11 and the air outlet 12 are not limited, and may be, for example, circular, oval, rectangular, etc., and may be designed according to needs, and are not expanded here.

With this structure, the flow path of air is: the air flows into the housing 1 from the air inlet 11 of the top wall 13 of the housing 1 and flows into the base wheel 2, is sucked into the inter-blade flow passages 41 between the plurality of blades 3, flows in the inter-blade flow passages 41 as a whole in the direction from the blade root 31 to the blade edge 32, is discharged from the blades at the outlet of each inter-blade flow passage 41, flows along the inner wall surface of the housing 1, is mixed, and is discharged from the air outlet 12 of the side wall 15 of the housing 1.

The specific structure of the side wall 15 is not limited, and in one embodiment, the side wall 15 has an inner side surface, i.e., an inner surface of the side wall 15. The inner side may include a flow directing surface 151, a flow dividing surface 152, and an outlet diffuser surface 153 that are connected in sequence. Wherein both the outlet diffuser surface 153 and the flow guide surface 151 extend to the air outlet 12. The outlet diffuser 153 may be inclined toward the edge of the sidewall 15 such that the outlet 12 is open. In one embodiment, the flow-directing surface 151 includes a continuous arcuate surface 1511 and a planar surface 1512 that may be smoothly transitioned. The arc surface 1511 connects the plane 1512 and the split surface 152, and the air flow can rotate along the arc surface 1511, so the region between the arc surface 1511 and the second circumferential surface P4 is referred to as a rotation field 42.

When the wheel disc 22 drives the blades 3 to rotate, air is sucked in from the air inlet 11 of the casing 1 and enters the inter-blade flow channels 41 between the adjacent blades 3 through the base wheel 2, and the blades 3 drive the air in the inter-blade flow channels 41 to rotate together. Then, the air flow in the inter-leaf flow path 41 is thrown out of the inter-leaf flow path 41 under the centrifugal action, wherein one part of the air flow can be thrown out of the air outlet 12 directly at a position close to the air outlet 12, and the other part of the air flow enters the rotation field 42, rotates along the cambered surface 1511 of the flow guiding surface 151, and flows to the air outlet 12 along the plane 1512 of the flow guiding surface 151. When the airflow is located near the flow dividing surface 152, a part of the air flows out of the air outlet 12 through the outlet diffusion surface 153, and the other part is divided into the rotation region 42, and continues to flow along the arc surface 1511 until flowing out of the air outlet 12. In other alternative embodiments, the inner wall surface of the side wall 15 may be provided with other shapes to guide the airflow direction in the housing 1 to achieve the desired effect, which is not shown here.

As shown in fig. 10, it will be understood by those skilled in the art that there is a connection point F between the first blade section 33 and the second blade section 34 in each blade 3, and the specific location of the connection point F is not limited, but the location of the connection point F may have some influence on the heat dissipation and noise reduction effects of the centrifugal fan 100.

As shown in fig. 7 and 10, in one embodiment, the top wall 13 is provided with a circular through hole, which constitutes the air inlet 11, and the first axis o passes through the center of the air inlet 11. The surface of the first blade section 33 and the second blade section 34 of each blade 3 where the connection point F is located is a first torus P5 (the first torus P5 is understood to be the surface swept by the connection section of the first blade section 33 and the second blade section 34 in each blade 3), and the first torus P5 coincides with the edge of the air inlet 11 along the axial direction. That is, the first torus P5 corresponds to and has the same size as the air inlet 11 in the axial direction, and thus the centrifugal fan 100 can achieve an optimal balance effect among noise, wind pressure, and efficiency.

Referring to fig. 14-15, fig. 14 is a flow field simulation diagram of a centrifugal fan according to an embodiment of the present application; fig. 15 is a sound pressure level versus rotational speed graph of a centrifugal fan according to an embodiment of the application and the centrifugal fan of fig. 2.

As shown in fig. 14 and compared with fig. 3, it can be seen from fig. 14 and fig. 3 that, compared with the structure of the centrifugal fan 100' in fig. 2, the air flows in the inter-blade flow channels 41 and the rotation zones 42 are smoother when the centrifugal fan 100 rotates in the embodiment of the application, so that the phenomena of unsteady fluctuation and flow separation such as air flow agitation are effectively reduced, and the vortex is basically eliminated. The reduction of eddy currents also means a reduction of noise.

As shown in fig. 15, the horizontal axis in fig. 15 represents the rotation speed of the centrifugal fan, the vertical axis represents the sound pressure level of noise, and two different curves represent test curves of the centrifugal fan 100' in fig. 2 and the centrifugal fan 100 according to the embodiment of the present application, respectively. It can be seen that the centrifugal fan 100 has a reduction in noise pressure level at each rotational speed compared to the centrifugal fan 100 ', and it is calculated that the noise of the centrifugal fan 100 is reduced by 4.5dB on average at the rotational speeds of 4500-6000, compared to the centrifugal fan 100'. Accordingly, the centrifugal fan 100 can satisfy both high-efficiency heat dissipation and low-noise operation.

It will be apparent to those skilled in the art that various modifications and variations can be made to the present application without departing from the spirit or scope of the application. Thus, it is intended that the present application also include such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

Claims

1. A centrifugal fan, comprising:

The shell is provided with an air inlet, an air outlet and an accommodating space, and the air inlet and the air outlet are communicated with the accommodating space;

The base wheel is positioned in the accommodating space and can rotate relative to the shell around a first axis;

The fan blades are arranged on the outer peripheral side of the base wheel at intervals and can rotate around the first axis under the drive of the base wheel;

Each of the plurality of blades has a blade root and a blade edge, the blade root faces the first axis, and the blade edge faces away from the first axis; in each fan blade, a plane in which a perpendicular line between the blade root and the first axis is located is a first radial surface, a plane in which a line between the blade root and the blade edge is located is a blade chord surface, an included angle is formed between the first radial surface and the blade chord surface, and each fan blade is integrally bent towards the respective first radial surface;

Each fan blade comprises a first fan blade section and a second fan blade section which are connected, one end of the first fan blade section, which is far away from the second fan blade section, forms the blade root, one end of the second fan blade section, which is far away from the first fan blade section, forms the blade edge, and the curvature of the second fan blade section is larger than that of the first fan blade section.

2. The centrifugal fan according to claim 1, wherein the inlet angle of the fan blades is 15 ° to 45 °; the air outlet angle of the fan blade is 90-120 degrees.

3. The centrifugal fan of claim 1, wherein a distance between two adjacent blades of said plurality of blades increases gradually from said blade root to said blade edge.

4. The centrifugal fan of claim 1, wherein said base wheel is rotatable in a first direction from a chord plane of each of said fan blades toward said first radial plane.

5. The centrifugal fan according to any one of claims 1 to 4, wherein said housing includes a top wall, a bottom wall, and a side wall, said top wall and said side wall being disposed at intervals along an extending direction of said first axis, said side wall being interposed between said top wall and said bottom wall, said top wall, said bottom wall, and said side wall surrounding said accommodation space; the air inlet is located on the top wall, and the air outlet is located on the side wall.

6. The centrifugal fan according to claim 5, wherein a circular through hole is provided in said top wall, said circular through hole constituting said air inlet, said first axis passing through a center of said air inlet;

The surface of each fan blade, where the connection point of the first fan blade section and the second fan blade section is located, is a first annular surface, and the first annular surface coincides with the edge of the air inlet along the extending direction of the first axis.

7. The centrifugal fan of any of claims 1-4, wherein each of said fan blades has first and second opposite end surfaces along an extension of said first axis, said first and second end surfaces being disposed in parallel.

8. The centrifugal fan of any of claims 1-4, wherein each of said blades extends along a bezier curve from said blade root to said blade edge.

9. A charging device comprising a centrifugal fan according to any one of claims 1-8.

10. The charging device of claim 9, further comprising an air duct having an air inlet end and an air outlet end, wherein the centrifugal fan is positioned within the air duct with the air inlet of the centrifugal fan disposed opposite the air inlet end of the air duct, wherein air flowing from the air outlet of the centrifugal fan is capable of flowing in the direction of extension of the air duct toward the air outlet end of the air duct; when the charging device charges the electronic equipment, the electronic equipment is arranged at the air outlet end of the air duct.

11. An electronic device comprising a centrifugal fan according to any one of claims 1-8.

12. The electronic device according to claim 11, further comprising a device housing having a housing chamber therein, and a vent provided in the device housing to communicate the housing chamber with the outside, wherein the centrifugal fan and the heat generating device are located in the housing chamber.