Centrifugal fan and air cooling system

Abstract

A centrifugal fan and an air cooling system are provided. The centrifugal fan (10) includes an impeller (12) disposed in a cavity (111) of a housing (11), and there is an airflow channel (115) between the impeller (12) and an inner side surface (112) of the cavity (111). The inner side surface (112) of the cavity (111) includes a convex surface (1121), a first guide surface (1122), and a second guide surface (1123) that are connected. A first distance from an intersection between the convex surface (1121) and the first guide surface (1122) to a circumferential side surface (121) of the impeller (12) is greater than a second distance from an intersection between the first guide surface (1122) and the second guide surface (1123) to the circumferential side surface (121). A position at which a width of the airflow channel is narrowest is far away from the convex surface, so that the second distance is smaller and the first distance is larger. This meets a requirement of not deteriorating noise while improving air outlet performance of the centrifugal fan, and implements performance improvement and noise reduction.

Description

[0001] This application claims priority to Chinese Patent Application No. 202311155752.0, filed with the China National Intellectual Property Administration on September 7, 2023 and entitled "CENTRIFUGAL FAN AND AIR COOLING SYSTEM", which is incorporated herein by reference in its entirety.TECHNICAL FIELD

[0002] This application relates to the field of electronic device heat dissipation technologies, and in particular, to a centrifugal fan and an air cooling system.BACKGROUND

[0003] As requirements for performance of electronic devices are continuously improved, power consumption and heat dissipation are also continuously deteriorated. Heat generated by the electronic devices needs to be evacuated to an environment in a timely manner. An air cooling technology is one of main heat dissipation manners of the electronic devices currently. Fans in air cooling systems greatly determine performance of air cooling heat dissipation of the devices. In addition, along with close integration of the electronic devices into people's life, noise of the fans also greatly affects use experience of the electronic devices. With reference to a requirement for lightness and thinness of the electronic devices and type features of the fans, the air cooling systems of the electronic devices usually use centrifugal fans to implement heat dissipation. However, in miniaturized electronic devices, it is difficult to balance a requirement of improving air outlet performance of the centrifugal fans and a problem of controlling wind noise.SUMMARY

[0004] Embodiments of this application provide a centrifugal fan and an air cooling system. The centrifugal fan can meet a requirement of improving air outlet performance of the fan while maintaining a low noise level, to achieve effect of improving heat dissipation performance of the fan and reducing the noise of the fan.

[0005] A first aspect of embodiments of this application provides a centrifugal fan. The centrifugal fan includes a housing and an impeller. The housing has a cavity, the housing has an air inlet and an air outlet, the impeller is rotatably disposed in the cavity, a circumferential side surface of the impeller and an inner side surface of the cavity are spaced apart to form an airflow channel, and the air outlet and the air inlet separately communicate with the airflow channel. Air flowing in the airflow channel can be accelerated by rotating the impeller, so that air outside the cavity can quickly enter from the air inlet, and is exhausted from the air outlet at a high speed after passing through the airflow channel, to implement a heat dissipation function.

[0006] The inner side surface of the cavity includes a convex surface, a first guide surface, and a second guide surface that are sequentially connected, the convex surface is connected to one end of the air outlet, the second guide surface is connected to the other end of the air outlet, and from one end at which the second guide surface is connected to the first guide surface to the end at which the second guide surface is connected to the air outlet, a distance between the second guide surface and the circumferential side surface of the impeller in a radial direction of the impeller gradually increases. In other words, starting from the end at which the second guide surface is connected to the first guide surface, the airflow channel has a region whose width (a width in the radial direction) gradually increases from narrow to wide. The region may be used as a pressurization region of the centrifugal fan. When an airflow passes through the region whose width gradually increases from narrow to wide, the airflow may be pressurized to increase an airflow rate of the fan.

[0007] A distance between an intersection line between the convex surface and the first guide surface and the circumferential side surface of the impeller in a radial direction is a first distance, and the first distance may be a length of a line segment between an intersection point between a radial line and the circumferential side surface of the impeller and an intersection point between the radial line and the intersection line.

[0008] A distance between an intersection line between the first guide surface and the second guide surface and the circumferential side surface of the impeller in a radial direction is a second distance, and the second distance may be a length of a line segment between an intersection point between a radial line and the circumferential side surface of the impeller and an intersection point between the radial line and the intersection line.

[0009] The second distance is less than the first distance. The convex surface may be formed by protruding from the inner side surface of the cavity, and the convex surface protrudes into the cavity, which causes a sudden size change of the airflow channel at a position of the convex surface. It may also be understood as that in a direction from the convex surface to the second guide surface, the airflow channel undergoes a width change from wide to narrow once at the position of the convex surface, and the airflow channel undergoes a width change from wide to narrow twice at a position of the first guide surface. A narrowest position of the width of the airflow channel is located at a position at which the second guide surface and the first guide surface are connected, and the narrowest position of the width of the airflow channel is far away from the convex surface (a position at which a sudden size change occurs). In comparison with that of a centrifugal fan in a related technology, the second distance may be small under a same noise requirement (for example, a same distance between the convex surface and the circumferential side surface), so that the centrifugal fan can have a stronger pressurization capability, and air outlet performance of the centrifugal fan is stronger. This helps improve heat dissipation performance of the centrifugal fan, and ensures that the noise is not deteriorated when the heat dissipation performance is improved.

[0010] In addition, because the second distance is less than the first distance, a width change between the convex surface and the circumferential side surface of the impeller has small impact on the performance of the centrifugal fan. Therefore, the first distance may be large, and a change rate of a cross-sectional area from a position of the air outlet to the convex surface is reduced. When the impeller rotates and passes through the position of the convex surface, a sudden size change at the position may be reduced to some extent, so that a pressure pulsation generated at the position of the convex surface is reduced, noise is reduced, and noise reduction of the centrifugal fan can be implemented. This can consider both performance improvement and noise reduction of the fan to some extent, to implement both performance improvement and noise reduction of the centrifugal fan.

[0011] In a possible implementation, from one end at which the first guide surface is connected to the convex surface to the end at which the first guide surface is connected to the second guide surface, a distance between the first guide surface and the circumferential side surface of the impeller in a radial direction gradually decreases, that is, a channel whose width gradually decreases is formed in a direction from the convex surface to the second guide surface. In other words, a channel that gradually decreases is disposed between the convex surface and the pressurization region formed between the second guide surface and the circumferential side surface, which facilitates reduction of the second distance compared with the first distance, has high transition smoothness, reduces noise caused by a width change, and the like. This helps further implement noise reduction under the condition of improving performance of the centrifugal fan.

[0012] In a possible implementation, from the end at which the first guide surface is connected to the convex surface to the end at which the first guide surface is connected to the second guide surface, the distance between the first guide surface and the circumferential side surface of the impeller in the radial direction monotonically decreases. This helps reduce structural design difficulty of the first guide surface and facilitates design and production implementation under a condition of gradually decreasing the distance between the first guide surface and the circumferential side surface of the impeller.

[0013] In a possible implementation, the first guide surface is an arched surface curving toward the impeller; the convex surface includes a first arc-shaped surface, and the first arc-shaped surface is an arched surface protruding into the cavity; and one end of the first arc-shaped surface is connected to the first guide surface to form a curved surface, and the intersection line between the convex surface and the first guide surface is a straight line that passes through a concave-convex inflection point of a curve of the curved surface and is perpendicular to the radial direction. In this way, the first guide surface and the convex surface are both arched surfaces, and have good smoothness. This facilitates smooth transition of an airflow in a gradually decreasing channel formed between the first guide surface and the circumferential side surface, and also helps improve smoothness of a connection between a second arc-shaped surface and the arched first guide surface, so that impact of a width size change on the airflow can be reduced, thereby helping improve air outlet and noise reduction performance of the centrifugal fan.

[0014] In a possible implementation, the second guide surface includes a second arc-shaped surface and a second plane that are connected, the second arc-shaped surface is connected to the first guide surface, and the second plane is connected to the air outlet. A part at which the second guide surface is connected to the first guide surface is the second arc-shaped surface, so that air in the pressurization region can flow more smoothly, and gas energy dissipation can be reduced. This is more conducive to implementing pressurization on the air, and is conducive to improving air outlet performance of the centrifugal fan.

[0015] In addition, a part at which the second guide surface is connected to the air outlet is the second plane, which is conducive to expanding an opening of the air outlet, and also conducive to improving air outlet performance of the centrifugal fan.

[0016] In a possible implementation, the second arc-shaped surface and the first guide surface are connected to together form an arched surface curving toward the impeller, and have good smoothness, so that the airflow can implement smooth transition from a gradually decreasing channel formed between the first guide surface and the circumferential side surface to a pressurization region channel formed between the second guide surface and the circumferential side surface, impact of a width size change on the airflow is further reduced, and pressurization effect on the airflow can also be ensured. This helps improve air outlet and noise reduction performance of the centrifugal fan.

[0017] In a possible implementation, the convex surface further includes a first plane connected to the other end of the first arc-shaped surface, and the first plane is connected to the air outlet; and from one end at which the first plane is connected to the first arc-shaped surface to one end at which the first plane is connected to the air outlet, the first plane is inclined outward from the cavity, so that a position of the outlet is open, and an opening of the air outlet can be further increased. This helps improve air outlet performance of the centrifugal fan.

[0018] In a possible implementation, the housing includes a side wall, and a bottom wall and a top wall that are provided opposite to each other; and the side wall is located between the bottom wall and the side wall, the side wall, the bottom wall, and the top wall together enclose the cavity, at least one of the bottom wall and the top wall is provided with the air inlet, the side wall is provided with the air outlet, and an inner surface of the side wall forms the inner side surface of the cavity. The housing is formed by assembling the bottom wall, the side wall, and the top wall. This helps improve flexibility of housing assembly and forming, and facilitates production implementation.

[0019] In a possible implementation, the impeller includes a hub and a plurality of fan blades, one end of the plurality of fan blades is fastened to the hub, and an end surface of the other end of the plurality of fan blades is flush with the circumferential side surface of the impeller. The plurality of fan blades help increase an airflow rate of the centrifugal fan, and improve heat dissipation performance of the centrifugal fan.

[0020] A second aspect of embodiments of this application provides an air cooling system. The air cooling system is configured to dissipate heat for a heat generation device, and includes a heat dissipation apparatus, a heat transfer apparatus, and the centrifugal fan according to any one of the foregoing implementations. The heat dissipation apparatus is located at an outlet of the centrifugal fan, the heat dissipation apparatus is connected to the heat transfer apparatus, and the heat transfer apparatus is configured to be connected to the heat generation device. The centrifugal fan is included, so that the centrifugal fan can achieve an objective of noise reduction when meeting a requirement of not deteriorating noise while improving air outlet performance, and can achieve effect of improving heat dissipation performance of the centrifugal fan and reducing noise of the centrifugal fan, thereby implementing high heat dissipation and low noise performance of the air cooling system. A sufficient heat dissipation capability can be well provided for the electronic device, so that performance of the electronic device is well released, thereby helping improve performance and noise reduction experience of the electronic device.BRIEF DESCRIPTION OF DRAWINGS

[0021] FIG. 1 is a diagram of a structure of an electronic device according to an embodiment of this application; FIG. 2 is a diagram of a cross-sectional structure of the electronic device in FIG. 1 along an A-A surface; FIG. 3 is a diagram of a structure of an air cooling system in an electronic device according to an embodiment of this application; FIG. 4 is a diagram of an internal structure of a centrifugal fan in a related technology; FIG. 5 is a diagram of a structure of a centrifugal fan according to an embodiment of this application; FIG. 6 is a diagram of a split structure of a centrifugal fan according to an embodiment of this application; FIG. 7 is a diagram of a structure of an impeller according to an embodiment of this application; FIG. 8 is a diagram of an internal structure of a centrifugal fan according to an embodiment of this application; FIG. 9 is a front view diagram of an internal structure of a centrifugal fan according to an embodiment of this application; FIG. 10 is a simulation diagram of a velocity field of a centrifugal fan in a related technology; and FIG. 11 is a simulation diagram of a velocity field of a centrifugal fan according to an embodiment of this application. Reference numerals:

[0022] 100: electronic device; 101: first external housing; 101a: housing cover; 101b: bottom housing; 1011: air vent; 102: second external housing; 103: heat generation device; 104: air cooling system; 10: centrifugal fan; 11: housing; 11a: bottom wall; 11b: side wall; 11c: top wall; 111: cavity; 112: inner side surface; 1121: convex surface; 1121a: first arc-shaped surface; 1121b: first plane; 1122: first guide surface; 1123: second guide surface; 1123a: second arc-shaped surface; 1123b: second plane; 113: air inlet; 114: air outlet; 115: airflow channel; 12: impeller; 121: circumferential side surface; 122: hub; 123: fan blade; 20: heat dissipation apparatus; 30: heat transfer apparatus; 105: circuit board; 106: button structure; 107: touch region; 108: display; 109: accommodating cavity; 110: power button. DESCRIPTION OF EMBODIMENTS

[0023] Terms used in implementations of this application are merely used to explain specific embodiments of this application, but are not intended to limit this application.

[0024] An electronic device provided in embodiments of this application may include but is not limited to a mobile phone, a tablet computer, a notebook computer, a two-in-one tablet / computer, an ultra-mobile personal computer (ultra-mobile personal computer, UMPC), a handheld computer, an intercom, a netbook, a POS machine, a personal digital assistant (personal digital assistant, PDA), a wearable device, a virtual reality (virtual reality, VR for short) device, an augmented reality (augmented reality, AR for short) device, a router, a power bank, mobile Wi-Fi, and an electronic device that has a heat dissipation requirement, for example, a vehicle-mounted device.

[0025] For example, in embodiments of this application, an example in which the electronic device is a notebook computer is used to describe the electronic device provided in embodiments of this application.

[0026] FIG. 1 is a diagram of a structure of an electronic device according to an embodiment of this application.

[0027] Refer to FIG. 1. The electronic device 100 may include two housings, for example, a first external housing 101 and a second external housing 102 respectively, and the electronic device 100 may further include a rotating mechanism (not shown in the figure). The first external housing 101 and the second external housing 102 are respectively located on two sides of the rotating mechanism, the first external housing 101 and the second external housing 102 may be separately connected to the rotating mechanism, and the rotating mechanism may implement rotating cooperation between the first external housing 101 and the second external housing 102, to implement opening and closing of a notebook computer.

[0028] The electronic device 100 may further include a button structure 106. The button structure 106 may be disposed on the first external housing 101. The button structure 106 may be configured to: identify operation information of a user, implement human-machine interaction with the user, and the like.

[0029] It should be understood that the button structure 106 may be a protruding button mechanical part, or the button structure 106 may be a virtual button or the like.

[0030] The first external housing 101 may further have a touch region 107, and the touch region 107 may also be used to identify operation information of the user, for example, gesture information, to enrich operation experience on the electronic device 100.

[0031] The first external housing 101 may further have a power button 110, and the power button 110 is configured to enable or disable the electronic device.

[0032] The electronic device 100 may further include a display 108. The display 108 may be disposed on the second external housing 102, and the display 108 is configured to display an image and the like.

[0033] Certainly, in some other examples, the display 108 may also be configured to identify operation information of the user, for example, operation position information and gesture information of the user.

[0034] The display 108 may include a display panel. The display panel may be a liquid crystal display (liquid crystal display, LCD for short), an organic light-emitting diode (organic light-emitting diode, OLED for short), an active matrix organic light-emitting diode or an active matrix organic light-emitting diode (active matrix organic light-emitting diode, AMOLED for short), a flexible light-emitting diode (flex light-emitting diode, FLED for short), a mini-LED, a micro-LED, a micro-OLED, a quantum dot light-emitting diode (quantum dot light-emitting diode, QLED for short), and the like.

[0035] The first external housing 101 may have an accommodating cavity, and a structural component of the electronic device may be accommodated in the accommodating cavity. In some examples, the second external housing 102 may also have an accommodating cavity, and the accommodating cavity of the second external housing 102 may also be configured to accommodate the structural component of the electronic device.

[0036] FIG. 2 is a diagram of a cross-sectional structure of the electronic device in FIG. 1 along an A-A surface.

[0037] Refer to FIG. 2. The first external housing 101 is used as an example. The first external housing 101 may include a bottom housing 101b and a housing cover 101a. The housing cover 101a may be disposed on the bottom housing 101b. The housing cover 101a and the bottom housing 101b together enclose the accommodating cavity 109. The structural component of the electronic device is fastened into the accommodating cavity 109.

[0038] The button structure 106, the touch region 107, the power button 110, and the like may be separately located on the housing cover 101a of the first external housing 101.

[0039] For example, the electronic device 100 may further include a processor (not shown in the figure). For example, the processor may include a central processing unit (central processing unit, CPU for short), an application processor (application processor, AP for short), a modem processor, a graphics processing unit (graphics processing unit, GPU for short), an image signal processor (image signal processor, ISP for short), a controller, a video codec, a digital signal processor (digital signal processor, DSP for short), a baseband processor, a neural-network processing unit (neural-network processing unit, NPU for short), and / or the like.

[0040] The processor may generate an operation control signal based on instruction operation code and a time sequence signal, to complete control of instruction fetching and instruction execution. A memory may be further disposed in the processor to store instructions and data.

[0041] The processor may include one or more interfaces. The processor may be connected to another component of the electronic device 100 through the interface. For example, the processor is connected to a module such as a sensor, an audio module, a display, or a camera of the electronic device 100.

[0042] For example, the processor may include a universal serial bus (universal serial bus, USB for short) interface (not shown in the figure). The USB interface may be provided on the first external housing 101, and may be configured to be connected to the electronic device and a peripheral device.

[0043] For example, the USB interface may be configured to be connected to a charger, to implement charging of the electronic device 100 through the charger. The USB interface may also be configured to be connected to another electronic device, for example, a storage device, to implement data transmission between the electronic device 100 and the another electronic device.

[0044] Certainly, in some other examples, the USB interface may also be configured to be connected to another electronic device, for example, may be configured to be connected to an external projection device or a VR device.

[0045] The electronic device 100 may further include a battery, a charging module, a power management module, and the like. The charging module is configured to receive a charging input of the charger, to charge the battery. For example, the charging management module may receive the charging input of the charger through the USB interface.

[0046] The power management module is configured to be connected to the battery, the charging management module, and the processor. When charging the battery, the charging management module may further supply power to the electronic device 100 through the power management module. The power management module receives an input of the battery and / or the charging management module, and may supply power to the processor, the memory, the display, the camera, and the like.

[0047] The power management module may be further configured to monitor the battery, for example, monitor parameters such as a battery capacity, a battery cycle count, and a battery health status (electric leakage or impedance).

[0048] The electronic device 100 may further include the camera (not shown in the figure), and an image shooting function may be implemented through the camera.

[0049] The electronic device 100 may further include an audio module, a speaker, a microphone, and the like (not shown in the figure), to implement an audio function of the electronic device 100. The audio module is configured to convert digital audio information into an analog audio signal output, and is also configured to convert an analog audio input into a digital audio signal. The audio module may be further configured to encode and decode an audio signal. In some embodiments, the audio module may be disposed in the processor, or a part of functional modules of the audio module are disposed in the processor.

[0050] The speaker, also referred to as a "loudspeaker", is configured to convert an audio electrical signal into a sound signal. The electronic device 100 may output a sound through the speaker, to play the sound. The microphone, also referred to as a "mike" or a "mic", is configured to convert a sound signal into an electrical signal. The electronic device 100 may receive an external sound through the microphone.

[0051] It may be understood that the structure shown in embodiments of this application does not constitute a specific limitation on the electronic device. In some other embodiments of this application, the electronic device may include more or fewer structural components than those shown in the figure, or combine some structural components, or split some components, or have different component arrangements.

[0052] For example, the electronic device 100 may further include a pressure sensor, a touch sensor, an antenna, a communication module, and the like.

[0053] Still refer to FIG. 2. The electronic device may further include a circuit board 105, a heat generation device 103 may be disposed on the circuit board 105, and both the heat generation device 103 and the circuit board 105 may be fastened into the accommodating cavity. The heat generation device 103 may be any device that generates heat during operation and that needs to dissipate heat, for example, may be the foregoing processor or battery.

[0054] It may be understood that the electronic device 100 may include one or more heat generation devices 103, and a specific quantity and types of heat generation devices 103 may be selected and specified as required.

[0055] To implement heat dissipation of the heat generation device 103, heat dissipation of the electronic device 100 may be implemented in an air cooling heat dissipation manner. For example, as shown in FIG. 2, the electronic device may further include an air cooling system 104, and the air cooling system 104 may implement heat dissipation of the electronic device.

[0056] The air cooling system 104 may include a centrifugal fan 10. The centrifugal fan 10 may be disposed near the heat generation device 103. The centrifugal fan 10 can accelerate air flowing in a surrounding environment (for example, in the accommodating cavity), and quickly exchange heat with the heat generation device 103, thereby implementing heat dissipation effect for heat of the heat generation device 103.

[0057] For example, the centrifugal fan 10 may be electrically connected to the circuit board 105, and the circuit board 105 can drive and control the centrifugal fan 10.

[0058] In some examples, an air vent 1011 may be further provided on the first external housing 101. For example, the air vent 1011 may be provided on a side wall of the bottom housing 101b, and the air vent 1011 may penetrate the side wall of the bottom housing 101b, so that the air vent 1011 can communicate with the accommodating cavity, that is, the accommodating cavity communicates with an external environment of the electronic device through the air vent 1011, thereby implementing air circulation inside and outside the electronic device, and further improving the heat dissipation effect.

[0059] It should be noted that FIG. 2 shows only one air vent 1011 provided on the first external housing 101. To implement air circulation inside and outside the electronic device, there may be a plurality of air vents 1011 on the first external housing 101. For example, there may be two air vents. One air vent may be used as an air inlet, and the other air vent may be used as an air outlet.

[0060] FIG. 3 is a diagram of a structure of an air cooling system in an electronic device according to an embodiment of this application.

[0061] Refer to FIG. 3. The air cooling system 104 may further include a heat dissipation apparatus 20 and a heat transfer apparatus 30. The heat transfer apparatus 30 may be configured to implement high-performance heat transfer between a heat generation device 103 and the heat dissipation apparatus 20.

[0062] In some examples, the heat transfer apparatus 30 may be an apparatus with high heat transfer performance, for example, a vapor chamber (vapor chamber, VC for short) or a heat pipe.

[0063] The heat dissipation apparatus 20 may be configured to provide a heat exchange site for a centrifugal fan 10 and the heat transfer apparatus 30, to implement more enhanced heat exchange effect. In some examples, the heat dissipation apparatus 20 may be an enhanced heat exchange apparatus such as a plain plate-fin heat sink or a pin-fin heat sink.

[0064] The heat dissipation apparatus 20 may be located at an air outlet 114 of the centrifugal fan 10, the heat transfer apparatus 30 may be located between the heat dissipation apparatus 20 and the heat generation device 103, and the heat transfer apparatus 30 may be separately in thermal contact with the heat dissipation apparatus 20 and the heat generation device 103, so that heat can be transferred between the heat generation device 103, the heat transfer apparatus 30, and the heat dissipation apparatus 20.

[0065] Heat generated by the heat generation device 103 may be efficiently conducted to the heat dissipation apparatus 20 through the heat transfer apparatus 30. When the centrifugal fan 10 runs, flowing of cold air may be accelerated, so that a high-speed airflow may be generated at the air outlet 114, and the high-speed airflow can pass through the heat dissipation apparatus 20, to implement heat exchange with the heat dissipation apparatus 20, and absorb heat in the heat dissipation apparatus 20 to form a hot airflow. The hot airflow may bring the heat to an environment outside the electronic device. For example, the hot airflow may be exhausted to the outside of the electronic device through an air vent on a bottom housing, to implement heat dissipation for the electronic device.

[0066] As requirements for performance of electronic devices are continuously improved, power consumption and heat dissipation are also continuously deteriorated. Heat of the electronic devices needs to be evacuated to an environment in a timely manner. Heat dissipation performance of air cooling systems in an air cooling manner greatly depends on fans, and high heat dissipation effect becomes one of main performance requirements pursued by the centrifugal fan. In addition, along with close integration of the electronic devices into people's daily life, noise of the fans also greatly affects use experience of the devices. Therefore, how to improve performance of centrifugal fans and reduce noise of the centrifugal fans is a key to improve capabilities of the air cooling systems in the air cooling manner.

[0067] FIG. 4 is a diagram of an internal structure of a centrifugal fan in a related technology.

[0068] Refer to FIG. 4. The common centrifugal fan 200 may include a fan blade 201 and a volute 202. The volute 202 has a cavity 202a, the fan blade 201 is disposed in the cavity 202a, and there is a gap between the fan blade 201 and an inner surface of a side wall of the volute 202, to form an airflow channel 203, that is, there is the airflow channel between the fan blade 201 and the inner surface of the side wall of the volute 202. The volute 202 may be separately provided with an air inlet (not shown in the figure) and an air outlet 202b, and the air inlet and the air outlet 202b may separately communicate with the airflow channel 203.

[0069] The fan blade 201 is rotatably disposed in the cavity 202a of the volute 202, the fan blade 201 can rotate, so that an airflow can be quickly exhausted from the air outlet through the air inlet and the airflow channel 203, and air flowing in an environment can be improved through the centrifugal fan 200. An arrow in FIG. 4 shows a flow direction of the airflow when the fan blade 201 rotates counterclockwise.

[0070] To improve performance of the centrifugal fan 200, a protruding volute tongue 204 may be disposed on the inner surface of the side wall of the volute 202, and the volute tongue 204 may be located at a position, on the inner surface of the side wall, near the air outlet 202b. Because the inner surface of the side wall protrudes to form the volute tongue 204, a distance between an outer surface of the volute tongue 204 and a circumferential side surface of the fan blade 201 is narrow, that is, the volute tongue 204 may be a part, on the inner surface of the side wall of the volute 202, closest to the fan blade 201, and the airflow channel 203 located between the volute tongue 204 and the fan blade 201 becomes narrow.

[0071] From a position of the volute tongue 204 to the air outlet 202b, the airflow channel 203 has a region that gradually increases from narrow to wide, for example, a pressurization region 202c in FIG. 4. When the airflow passes through the region from narrow to wide, the airflow may be pressurized to increase an airflow rate of the fan.

[0072] In addition, the protruding volute tongue 204 can further form a physical partition between the pressurization region 202c and a region of the air outlet 202b, to prevent air of the air outlet 202b of the fan from being brought into the pressurization region 202c by rotation of the fan blade 201, causing deterioration of air outlet performance of the fan.

[0073] Extensive structural design experience indicates that a smaller gap between the volute tongue and the circumferential side surface of the fan blade indicates a higher airflow rate of the centrifugal fan 200 and better heat dissipation performance. However, the narrower a width of the airflow channel at the volute tongue, the more intense a pressure pulsation of air is formed in the rapidly narrowing channel when each fan blade rotates and brushes through the channel, to generate a large amount of noise. Therefore, a smaller gap between the volute tongue and the circumferential side surface of the fan blade indicates greater noise of the centrifugal fan. It is difficult to ensure that the noise is not deteriorated when the heat dissipation performance of the centrifugal fan is improved.

[0074] In view of this, embodiments of this application provide a centrifugal fan, so that an objective of noise reduction when meeting a requirement of not deteriorating noise while improving air outlet performance of the centrifugal fan can be implemented, and effect of improving heat dissipation performance of the centrifugal fan and reducing noise of the centrifugal fan can be achieved. The centrifugal fan can provide a sufficient heat dissipation capability for the electronic device, to support release of performance of the electronic device, thereby helping improve performance of the electronic device, and enabling a user to have good heat dissipation / noise reduction experience.

[0075] FIG. 5 is a diagram of a structure of a centrifugal fan according to an embodiment of this application.

[0076] Refer to FIG. 5. The centrifugal fan 10 may include a housing 11 and an impeller 12. The housing 11 is used as a main bearing mechanical part of the centrifugal fan 10. The housing 11 may have a cavity 111 configured to accommodate the impeller 12, or may be configured to accommodate another mechanical part of the centrifugal fan 10.

[0077] An air inlet 113 and an air outlet 114 are provided on the housing 11. The air inlet 113 and the air outlet 114 may be through holes on the housing 11 respectively. The air inlet 113 may communicate with the cavity 111 in the housing 11, and the air outlet 114 may also communicate with the cavity 111 in the housing 11.

[0078] It should be noted that in this embodiment of this application, a formed material of the housing 11 is not limited. For example, the formed material of the housing 11 may be plastic, metal, alloy, or the like.

[0079] An assembly and forming manner of the housing 11 is not limited either. For example, the housing 11 may be a mechanical part that is integrally formed. For example, the housing 11 may be a mechanical part that is integrally formed in a manner such as injection forming.

[0080] Alternatively, in some examples, the housing 11 may be formed by assembling a split mechanical part. A specific material and an assembly manner may be selected and specified based on an actual requirement.

[0081] In this embodiment of this application, an example in which the housing 11 is formed by assembling the split mechanical part is used for description. The housing 11 is formed by assembling the split mechanical part, and has high design flexibility. This helps reduce production design difficulty and facilitate implementation.

[0082] FIG. 6 is a diagram of a split structure of a centrifugal fan according to an embodiment of this application.

[0083] For example, with reference to FIG. 5 and FIG. 6, the housing 11 may include a bottom wall 11a, a side wall 11b, and a top wall 11c. The top wall 11c and the bottom wall 11a may be provided opposite to each other, and the side wall 11b may be located between the bottom wall 11a and the top wall 11c. In this way, the top wall 11c, the side wall 11b, and the bottom wall 11a may together enclose the cavity 111 of the housing 11, and an inner surface (facing a box) of the side wall 11b may form an inner side surface 112 of the cavity 111.

[0084] The bottom wall 11a and the top wall 11c may be planes respectively, the side wall 11b is located between the bottom wall 11a and the top wall 11c, and the side wall 11b may have a specific extension height in a direction perpendicular to the bottom wall 11a and the top wall 11c, to ensure that the bottom wall 11a, the top wall 11c, and the side wall 11b can form the cavity 111.

[0085] At least one of the top wall 11c or the bottom wall 11a may be provided with the air inlet 113, and the side wall 11b may be provided with the air outlet 114, that is, the air outlet 114 is located between the top wall 11c and the bottom wall 11a.

[0086] It should be noted that there may be one air inlet 113, for example, as shown in FIG. 5 and FIG. 6, and a through hole may be provided on the top wall 11c to form the air inlet 113.

[0087] Certainly, in some other examples, there may alternatively be a plurality of air inlets 113. For example, there may be two air inlets. For example, through holes may be respectively provided on the top wall 11c and the bottom wall 11a to form two air inlets.

[0088] In this embodiment of this application, an example in which one air inlet 113 is provided on the top wall 11c is used for description.

[0089] The impeller 12 may be rotatably disposed in the cavity 111 enclosed by the bottom wall 11a, the side wall 11b, and the top wall 11c. The impeller 12 may rotate around an axis o (as shown in FIG. 7), and a direction parallel to the axis is an axial direction of the impeller 12.

[0090] A shape of the impeller 12 may be a circle, and the axis of the impeller 12 may be a straight line that passes through a center of the impeller 12 and is perpendicular to the impeller 12. In this embodiment of this application, a radial direction is a direction parallel to a diameter / radius of the impeller 12, and the axial direction of the impeller 12 may be perpendicular to the radial direction. It may be understood that the radial direction may be any direction (for example, a y direction in FIG. 7) that passes through the center of the impeller 12 and is perpendicular to the axial direction of the impeller 12, and the radial direction may include a plurality of directions.

[0091] The air inlet 113 on the housing 11 may be located on one side of the impeller 12 in the axial direction, and the air outlet 114 may be located on one side of the impeller 12 in the radial direction (refer to FIG. 5).

[0092] FIG. 7 is a diagram of a structure of an impeller according to an embodiment of this application.

[0093] Refer to FIG. 7. The impeller 12 may include a circumferential side surface 121, and the circumferential side surface 121 may be an outermost surface of the impeller 12 in a circumferential direction. It may also be understood as that the circumferential side surface 121 is a circumferential surface formed by using an axis o of the impeller 12 as a center line and using a radius of the impeller 12 as a radius.

[0094] The impeller 12 may include a hub 122 and a plurality of fan blades 123. The plurality of fan blades 123 may be fastened to the hub 122, and the hub 122 may drive the plurality of fan blades 123 to rotate, so that the impeller 12 rotates.

[0095] The plurality of fan blades 123 may be distributed on the hub 122 in an array around the axis o, and the plurality of fan blades 123 may be arranged at an equal gap. The plurality of fan blades 123 help increase an airflow rate of a centrifugal fan 10, and improve heat dissipation performance of the centrifugal fan 10.

[0096] A shape of the hub 122 may be a circle, and the fan blades 123 may be approximately in an arc-shaped plate structure. One end of the plurality of fan blades 123 may be fastened to the hub 122, and an end surface of the other end may be flush with the circumferential side surface 121 of the impeller 12.

[0097] A specific quantity of fan blades 123 is not limited in this embodiment of this application, and may be specifically selected and specified based on an actual requirement.

[0098] The impeller 12 may further include an annular reinforcing member 124. The annular reinforcing member 124 is fastened to one end, of the plurality of fan blades 123, facing away from the hub 122, and the plurality of fan blades 123 are connected and fastened into a whole mechanical part through the reinforcing member 124, which is conducive to reinforcing strength of the fan blades 123, and improving stability of the entire impeller 12. An outer side surface of the annular reinforcing member 124 in the circumferential direction may be flush with the circumferential side surface 121 of the impeller 12. In some examples, the outer side surface of the annular reinforcing member 124 in the circumferential direction and an end surface of the other end, of the plurality of fan blades 123, facing away from the hub 122 may together form the circumferential side surface 121 of the impeller 12.

[0099] The centrifugal fan 10 may further include a drive structure (not shown in the figure). For example, the drive structure may be fastened to the hub 122, and the drive structure is connected to the hub 122 and drives the hub 122 to rotate, so that the hub 122 drives the plurality of fan blades 123 to rotate together.

[0100] FIG. 8 is a diagram of an internal structure of a centrifugal fan according to an embodiment of this application. It should be noted that a top wall of the centrifugal fan is not shown in FIG. 8.

[0101] Refer to FIG. 8. An impeller 12 is rotatably assembled in a cavity 111, and there is a gap between a circumferential side surface 121 of the impeller 12 and an inner side surface 112 (namely, an inner surface of a side wall 11b) of the cavity 111, to form an airflow channel 115. The airflow channel 115 separately communicates with an air outlet 114 on the side wall 11b and an air inlet on the top wall.

[0102] Air flowing in the airflow channel 115 can be accelerated by rotating the impeller 12, so that air outside the cavity 111 can quickly enter from the air inlet, and is exhausted from the air outlet 114 at a high speed after passing through the airflow channel 115.

[0103] A rotation direction of the impeller 12 may be clockwise rotation, or a rotation direction of the impeller 12 may be counterclockwise rotation.

[0104] FIG. 9 is a front view diagram of an internal structure of a centrifugal fan according to an embodiment of this application.

[0105] With reference to FIG. 9, an inner side surface 112 of a cavity 111 may include a convex surface 1121, a first guide surface 1122, and a second guide surface 1123.

[0106] One end of the convex surface 1121 is connected to one end of an air outlet 114, the other end of the convex surface 1121 is connected to one end of the first guide surface 1122, and an intersection line (refer to the intersection line L1 in FIG. 8) may be formed at a position at which the convex surface 1121 is connected to the first guide surface 1122.

[0107] The other end of the first guide surface 1122 is connected to one end of the second guide surface 1123, and an intersection line (refer to the intersection line L2 in FIG. 8) may be formed at a position at which the first guide surface 1122 is connected to the second guide surface 1123. The other end of the second guide surface 1123 is connected to the other end of the air outlet 114.

[0108] A distance between the intersection line L1 between the convex surface 1121 and the first guide surface 1122 and a circumferential side surface 121 of the impeller 12 in a radial direction is a first distance, and may be used as a radial line (a straight line, in the radial direction, passing through a center) that separately intersects an axis o and the intersection line L1. For example, the radial line may be perpendicular to the axis o and the intersection line L1, and the first distance may be a length of a line segment between an intersection point between the radial line and the circumferential side surface 121 of the impeller 12 and an intersection point between the radial line and the intersection line L1.

[0109] For example, FIG. 9 is a front view diagram of the centrifugal fan 10. Projecting a structure of the centrifugal fan to a bottom wall 11a is used as an example. A projection of the axis of the impeller 12 on the bottom wall 11a is o1, a projection of the intersection line L1 between the convex surface 1121 and the first guide surface 1122 on the bottom wall 11a is a point o2, a radial line passing through the projection point o1 of the connection axis and the projection o2 of the intersection line L1 is y1, and the first distance d1 is a length of a line segment between an intersection point between the radial line y1 and the circumferential side surface 121 of the impeller 12 and an intersection point between the radial line y1 and the projection point o2 of the intersection line.

[0110] Correspondingly, a distance between the intersection line L2 between the first guide surface 1122 and the second guide surface 1123 and the circumferential side surface 121 of the impeller 12 in a radial direction is a second distance, and may be used as a radial line that separately intersects the axis o and the intersection line L2. For example, the radial line may be perpendicular to the axis o and the intersection line L2, and the second distance may be a length of a line segment between an intersection point between the radial line and the circumferential side surface 121 of the impeller 12 and an intersection point between the radial line and the intersection line L2.

[0111] For example, as shown in FIG. 9, projecting the structure of the centrifugal fan to the bottom wall 11a is used as an example. A projection of the intersection line between the first guide surface 1122 and the second guide surface 1123 on the bottom wall 11a is a point o3, a radial line passing through the projection point o1 of the connection axis and the projection point o3 of the intersection line L2 is y2, and the second distance d2 is a length of a line segment between an intersection point between the radial line y2 and the circumferential side surface 121 of the impeller 12 and an intersection point between the radial line y2 and the projection o3 of the intersection line.

[0112] It may be understood that the radial line y1 and the radial line y2 respectively correspond to two different radial directions, the two radial directions may intersect, and there is an included angle between the two radial directions.

[0113] The second distance d2 is less than the first distance d1. To be specific, a distance between the intersection line L2 between the second guide surface 1123 and the first guide surface 1122 and the circumferential side surface 121 is less than a distance between the intersection line L1 between the convex surface 1121 and the first guide surface 1122 and the circumferential side surface 121. It may be understood that the convex surface 1121 may be formed by protruding from the inner side surface 112 of the cavity 111, and the convex surface 1121 protrudes into the cavity 111, which causes a sudden size change of a width (a width in the radial direction) of the airflow channel 115 at a position of the convex surface 1121, in other words, in a direction from the convex surface 1121 to the second guide surface 1123, the airflow channel 115 undergoes a width change from wide to narrow once at the position of the convex surface 1121, and the airflow channel 115 undergoes a width change from wide to narrow twice at a position of the first guide surface 1122.

[0114] With reference to FIG. 8 and FIG. 9, from one end at which the second guide surface 1123 is connected to the first guide surface 1122 to the end at which the second guide surface 1123 is connected to the air outlet 114, a distance between the second guide surface 1123 and the circumferential side surface 121 of the impeller 12 in a radial direction may gradually increase. In other words, starting from the end (for example, the intersection line L2) at which the second guide surface 1123 is connected to the first guide surface 1122, the airflow channel 115 has a region whose width gradually increases from narrow to wide. The region may be used as a pressurization region of the centrifugal fan, for example, a pressurization region 10a shown in FIG. 9. When an airflow passes through the region whose width gradually increases from narrow to wide, the airflow is pressurized to increase an airflow rate of the fan.

[0115] Still refer to FIG. 9. In other words, a minimum distance between the inner side surface 112 of the cavity 111 and an inner surface of the impeller 12 in the radial direction is located at a position of the intersection line between the second guide surface 1123 and the first guide surface 1122, a narrowest position of the width of the airflow channel 115 is located at a position at which the second guide surface 1123 and the first guide surface 1122 are connected, and the narrowest position of the width of the airflow channel 115 is far away from the convex surface 1121 (a position at which a sudden size change occurs). In comparison with that in a related technology, the second distance d2 may be small under a same noise requirement (for example, under a condition of a same distance between the convex surface and the circumferential side surface), so that the centrifugal fan can have a stronger pressurization capability, and air outlet performance of the centrifugal fan is stronger. This helps improve heat dissipation performance of the centrifugal fan, and ensures that the noise is not deteriorated when the heat dissipation performance is improved.

[0116] In addition, because the second distance d2 is less than the first distance d1, a width change between the convex surface 1121 and the circumferential side surface 121 of the impeller 12 has small impact on the performance of the centrifugal fan 10. Therefore, in comparison with that in the related technology, the first distance d1 may be large, and a change rate of a cross-sectional area from a position of the air outlet 114 to the convex surface 1121 is reduced. When the impeller 12 rotates and passes through the position of the convex surface 1121, a sudden size change at the position may be reduced to some extent, so that a pressure pulsation generated at the position of the convex surface 1121 is reduced, noise is reduced, and noise reduction of the centrifugal fan can be implemented. This can consider both performance improvement and noise reduction of the fan to some extent, to implement both performance improvement and noise reduction of the centrifugal fan.

[0117] Still refer to FIG. 9. From one end at which the first guide surface 1122 is connected to the convex surface 1121 to the end at which the first guide surface 1122 is connected to the second guide surface 1123, a distance between the first guide surface 1122 and the circumferential side surface 121 of the impeller 12 in a radial direction gradually decreases, that is, a channel whose width gradually decreases is formed in a direction from the convex surface 1121 to the second guide surface 1123.

[0118] In other words, a channel that gradually decreases is disposed between the convex surface 1121 and the pressurization region formed between the second guide surface 1123 and the circumferential side surface 121, which facilitates reduction of the second distance compared with the first distance, has high transition smoothness, reduces noise caused by a width change, and the like. This helps further implement noise reduction under the condition of improving performance of the centrifugal fan 10.

[0119] For example, from one end at which the first guide surface 1122 is connected to the convex surface 1121 to the end at which the first guide surface 1122 is connected to the second guide surface 1123, a distance between the first guide surface 1122 and the circumferential side surface 121 of the impeller 12 in the radial direction may gradually monotonically decrease. This helps reduce structural design difficulty of the first guide surface 1122 and facilitates design and production implementation under a condition of gradually decreasing the distance between the first guide surface 1122 and the circumferential side surface 121 of the impeller 12.

[0120] The first guide surface 1122 may be an arched surface curving toward the impeller 12, so that the first guide surface 1122 is an arched surface and has good smoothness. This facilitates smooth transition of an airflow in a gradually decreasing channel formed between the first guide surface 1122 and the circumferential side surface 121, so that impact of a width size change on the airflow can be reduced, thereby helping improve air outlet and noise reduction performance of the centrifugal fan 10.

[0121] Still refer to FIG. 9. The convex surface 1121 may include a first arc-shaped surface 1121a and a first plane 1121b. One end of the first arc-shaped surface 1121a may be connected to the first guide surface 1122, the first arc-shaped surface 1121a may be an arched surface protruding into the impeller 12, and the first arc-shaped surface 1121a is connected to the first guide surface 1122 to form a curved surface. This helps improve smoothness of a connection between the first arc-shaped surface 1121a and the arc-shaped first guide surface 1122, and reduces impact of a width size change on the airflow.

[0122] The intersection line between the convex surface 1121 and the first guide surface 1122 is an intersection line between the first arc-shaped surface 1121a that is convex and the first guide surface 1122 that is concave, and the first arc-shaped surface 1121a is connected to the first guide surface 1122 to form a curved surface, a straight line that passes through a concave-convex inflection point of a curve of the curved surface and is perpendicular to the radial direction is the intersection line between the first arc-shaped surface 1121a and the first guide surface 1122. As shown in FIG. 9, a projection, on the bottom wall 11a, of the curved surface formed by the first arc-shaped surface 1121a that is convex and the first guide surface 1122 that is concave is the curve of the curved surface, and the concave-convex inflection point of the curve is a point o2, the straight line that passes through the inflection point o2 and is perpendicular to the radial direction is the intersection line (L1 in FIG. 8) between the convex surface 1121 and the first guide surface 1122.

[0123] The other end of the first arc-shaped surface 1121a may be connected to one end of the first plane 1121b, the other end of the first plane 1121b may be connected to one end of the air outlet 114, and a smooth transition connection may be implemented between the other end of the first arc-shaped surface 1121a and the end of the first plane 1121b.

[0124] The first plane 1121b may be an inclined plane. Specifically, from one end at which the first plane 1121b is connected to the first arc-shaped surface 1121a to one end at which the first plane 1121b is connected to the air outlet 114, the first plane 1121b is inclined outward from the cavity 111, so that a position of the air outlet 114 may be open, and an opening of the air outlet 114 can be further increased. This helps improve air outlet performance of the centrifugal fan.

[0125] Still refer to FIG. 9. The second guide surface 1123 may include a second arc-shaped surface 1123a and a second plane 1123b. One end of the second arc-shaped surface 1123a is connected to the first guide surface 1122, the other end of the second arc-shaped surface 1123a is connected to one end of the second plane 1123b, a smooth transition connection may be implemented between the other end of the second arc-shaped surface 1123a and the end of the second plane 1123b, and the other end of the second plane 1123b is connected to the other end of the air outlet 114. Starting from the end at which the second guide surface 1123 is connected to the first guide surface 1122, a width of the airflow channel 115 gradually increases from narrow to wide and may be used as a pressurization region. A part at which the second guide surface 1123 is connected to the first guide surface 1122 is the second arc-shaped surface 1123a, so that air in the pressurization region can flow more smoothly, and gas energy dissipation can be reduced. This is more conducive to implementing pressurization on the air, and is conducive to improving air outlet performance of the centrifugal fan.

[0126] In addition, a part at which the second guide surface 1123 is connected to the air outlet 114 is the second plane 1123b, which is conducive to expanding an opening of the air outlet 114, and also conducive to improving air outlet performance of the centrifugal fan.

[0127] The first guide surface 1122 and the second guide surface 1123 are connected to together form an arched surface curving toward the impeller 12, and have good smoothness, so that the airflow can implement smooth transition from a gradually decreasing channel formed between the first guide surface 1122 and the circumferential side surface 121 to a pressurization region channel formed between the second guide surface 1123 and the circumferential side surface 121, impact of a width size change on the airflow is further reduced, and pressurization effect on the airflow can also be ensured. This helps improve air outlet and noise reduction performance of the centrifugal fan.

[0128] FIG. 10 is a simulation diagram of a velocity field of a centrifugal fan in a related technology. FIG. 11 is a simulation diagram of a velocity field of a centrifugal fan according to an embodiment of this application.

[0129] Simulation is performed on the velocity field of the centrifugal fan 200 in the foregoing related technology in this embodiment and the velocity field of the centrifugal fan 10 in this embodiment of this application. In the related technology, a gap between a volute tongue of the centrifugal fan 200 and a circumferential side surface of a fan blade is equal to a first distance d1 of the centrifugal fan 10 in this embodiment of this application.

[0130] With reference to FIG. 10 and FIG. 11, under a condition that rotation speeds of an impeller are the same, an airflow rate of the centrifugal fan 200 in the related technology is 2.56 cfm, where cfm is an airflow rate unit, which means air volume-cubic feet per minute (cubic feet per minute), and is a volume of air passing through a cross section of an air outlet (or an air inlet) of the fan per unit of time.

[0131] An airflow rate of the centrifugal fan 10 in this embodiment of this application is 2.84 cfm. In other words, under a condition of a same rotation speed, the airflow rate of the centrifugal fan in this embodiment of this application increases by 11%.

[0132] A maximum air outlet velocity of the centrifugal fan 200 in the related technology is 23.28 m / s, where m / s is a wind velocity unit, which means meter per second, and is a distance that air travels. A maximum air outlet velocity of the centrifugal fan 10 in this embodiment of this application is 23.19 m / s, wind velocities are equivalent, and air outlet noise effect of the centrifugal fan is also basically equivalent.

[0133] In conclusion, the centrifugal fan provided in embodiments of this application can significantly increase the airflow rate under a condition of a same noise requirement, and correspondingly can achieve significant noise reduction effect under a condition of a same airflow rate requirement.

[0134] It should be noted that values and value ranges in embodiments of this application are approximate values, and there may be an error within a specific range. A person skilled in the art may consider that the error is negligible.

[0135] In the descriptions of embodiments of this application, it should be noted that unless otherwise clearly specified and limited, the term "installation", "connection to", or "connection" should be understood in a broad sense, for example, may be fastening, or may be an indirect connection through an intermediate medium, or may be internal communication between two elements or an interaction relationship between two elements. A person of ordinary skill in the art may understand specific meanings of the foregoing terms in embodiments of this application based on specific cases. The terms such as "first", "second", "third", "fourth", and the like (if any) are intended to distinguish between similar objects but do not necessarily indicate a specific order or sequence.

[0136] Finally, it should be noted that the foregoing embodiments are merely used to describe the technical solutions in embodiments of this application, but not to limit the technical solutions. Although embodiments of this application are described in detail with reference to the foregoing embodiments, a person of ordinary skill in the art should understand that the technical solutions recorded in the foregoing embodiments may still be modified, or some or all of technical features thereof may be equivalently replaced. However, these modifications or replacements do not depart from the scope of the technical solutions in embodiments of this application.

Examples

Embodiment Construction

[0023]Terms used in implementations of this application are merely used to explain specific embodiments of this application, but are not intended to limit this application.

[0024]An electronic device provided in embodiments of this application may include but is not limited to a mobile phone, a tablet computer, a notebook computer, a two-in-one tablet / computer, an ultra-mobile personal computer (ultra-mobile personal computer, UMPC), a handheld computer, an intercom, a netbook, a POS machine, a personal digital assistant (personal digital assistant, PDA), a wearable device, a virtual reality (virtual reality, VR for short) device, an augmented reality (augmented reality, AR for short) device, a router, a power bank, mobile Wi-Fi, and an electronic device that has a heat dissipation requirement, for example, a vehicle-mounted device.

[0025]For example, in embodiments of this application, an example in which the electronic device is a notebook computer is used to describe the electronic...

[0001] This application claims priority to Chinese Patent Application No. 202311155752.0, filed with the China National Intellectual Property Administration on September 7, 2023 and entitled "CENTRIFUGAL FAN AND AIR COOLING SYSTEM", which is incorporated herein by reference in its entirety.TECHNICAL FIELD

[0002] This application relates to the field of electronic device heat dissipation technologies, and in particular, to a centrifugal fan and an air cooling system.BACKGROUND

[0003] As requirements for performance of electronic devices are continuously improved, power consumption and heat dissipation are also continuously deteriorated. Heat generated by the electronic devices needs to be evacuated to an environment in a timely manner. An air cooling technology is one of main heat dissipation manners of the electronic devices currently. Fans in air cooling systems greatly determine performance of air cooling heat dissipation of the devices. In addition, along with close integration of the electronic devices into people's life, noise of the fans also greatly affects use experience of the electronic devices. With reference to a requirement for lightness and thinness of the electronic devices and type features of the fans, the air cooling systems of the electronic devices usually use centrifugal fans to implement heat dissipation. However, in miniaturized electronic devices, it is difficult to balance a requirement of improving air outlet performance of the centrifugal fans and a problem of controlling wind noise.SUMMARY

[0004] Embodiments of this application provide a centrifugal fan and an air cooling system. The centrifugal fan can meet a requirement of improving air outlet performance of the fan while maintaining a low noise level, to achieve effect of improving heat dissipation performance of the fan and reducing the noise of the fan.

[0005] A first aspect of embodiments of this application provides a centrifugal fan. The centrifugal fan includes a housing and an impeller. The housing has a cavity, the housing has an air inlet and an air outlet, the impeller is rotatably disposed in the cavity, a circumferential side surface of the impeller and an inner side surface of the cavity are spaced apart to form an airflow channel, and the air outlet and the air inlet separately communicate with the airflow channel. Air flowing in the airflow channel can be accelerated by rotating the impeller, so that air outside the cavity can quickly enter from the air inlet, and is exhausted from the air outlet at a high speed after passing through the airflow channel, to implement a heat dissipation function.

[0006] The inner side surface of the cavity includes a convex surface, a first guide surface, and a second guide surface that are sequentially connected, the convex surface is connected to one end of the air outlet, the second guide surface is connected to the other end of the air outlet, and from one end at which the second guide surface is connected to the first guide surface to the end at which the second guide surface is connected to the air outlet, a distance between the second guide surface and the circumferential side surface of the impeller in a radial direction of the impeller gradually increases. In other words, starting from the end at which the second guide surface is connected to the first guide surface, the airflow channel has a region whose width (a width in the radial direction) gradually increases from narrow to wide. The region may be used as a pressurization region of the centrifugal fan. When an airflow passes through the region whose width gradually increases from narrow to wide, the airflow may be pressurized to increase an airflow rate of the fan.

[0007] A distance between an intersection line between the convex surface and the first guide surface and the circumferential side surface of the impeller in a radial direction is a first distance, and the first distance may be a length of a line segment between an intersection point between a radial line and the circumferential side surface of the impeller and an intersection point between the radial line and the intersection line.

[0008] A distance between an intersection line between the first guide surface and the second guide surface and the circumferential side surface of the impeller in a radial direction is a second distance, and the second distance may be a length of a line segment between an intersection point between a radial line and the circumferential side surface of the impeller and an intersection point between the radial line and the intersection line.

[0009] The second distance is less than the first distance. The convex surface may be formed by protruding from the inner side surface of the cavity, and the convex surface protrudes into the cavity, which causes a sudden size change of the airflow channel at a position of the convex surface. It may also be understood as that in a direction from the convex surface to the second guide surface, the airflow channel undergoes a width change from wide to narrow once at the position of the convex surface, and the airflow channel undergoes a width change from wide to narrow twice at a position of the first guide surface. A narrowest position of the width of the airflow channel is located at a position at which the second guide surface and the first guide surface are connected, and the narrowest position of the width of the airflow channel is far away from the convex surface (a position at which a sudden size change occurs). In comparison with that of a centrifugal fan in a related technology, the second distance may be small under a same noise requirement (for example, a same distance between the convex surface and the circumferential side surface), so that the centrifugal fan can have a stronger pressurization capability, and air outlet performance of the centrifugal fan is stronger. This helps improve heat dissipation performance of the centrifugal fan, and ensures that the noise is not deteriorated when the heat dissipation performance is improved.

[0010] In addition, because the second distance is less than the first distance, a width change between the convex surface and the circumferential side surface of the impeller has small impact on the performance of the centrifugal fan. Therefore, the first distance may be large, and a change rate of a cross-sectional area from a position of the air outlet to the convex surface is reduced. When the impeller rotates and passes through the position of the convex surface, a sudden size change at the position may be reduced to some extent, so that a pressure pulsation generated at the position of the convex surface is reduced, noise is reduced, and noise reduction of the centrifugal fan can be implemented. This can consider both performance improvement and noise reduction of the fan to some extent, to implement both performance improvement and noise reduction of the centrifugal fan.

[0011] In a possible implementation, from one end at which the first guide surface is connected to the convex surface to the end at which the first guide surface is connected to the second guide surface, a distance between the first guide surface and the circumferential side surface of the impeller in a radial direction gradually decreases, that is, a channel whose width gradually decreases is formed in a direction from the convex surface to the second guide surface. In other words, a channel that gradually decreases is disposed between the convex surface and the pressurization region formed between the second guide surface and the circumferential side surface, which facilitates reduction of the second distance compared with the first distance, has high transition smoothness, reduces noise caused by a width change, and the like. This helps further implement noise reduction under the condition of improving performance of the centrifugal fan.

[0012] In a possible implementation, from the end at which the first guide surface is connected to the convex surface to the end at which the first guide surface is connected to the second guide surface, the distance between the first guide surface and the circumferential side surface of the impeller in the radial direction monotonically decreases. This helps reduce structural design difficulty of the first guide surface and facilitates design and production implementation under a condition of gradually decreasing the distance between the first guide surface and the circumferential side surface of the impeller.

[0013] In a possible implementation, the first guide surface is an arched surface curving toward the impeller; the convex surface includes a first arc-shaped surface, and the first arc-shaped surface is an arched surface protruding into the cavity; and one end of the first arc-shaped surface is connected to the first guide surface to form a curved surface, and the intersection line between the convex surface and the first guide surface is a straight line that passes through a concave-convex inflection point of a curve of the curved surface and is perpendicular to the radial direction. In this way, the first guide surface and the convex surface are both arched surfaces, and have good smoothness. This facilitates smooth transition of an airflow in a gradually decreasing channel formed between the first guide surface and the circumferential side surface, and also helps improve smoothness of a connection between a second arc-shaped surface and the arched first guide surface, so that impact of a width size change on the airflow can be reduced, thereby helping improve air outlet and noise reduction performance of the centrifugal fan.

[0014] In a possible implementation, the second guide surface includes a second arc-shaped surface and a second plane that are connected, the second arc-shaped surface is connected to the first guide surface, and the second plane is connected to the air outlet. A part at which the second guide surface is connected to the first guide surface is the second arc-shaped surface, so that air in the pressurization region can flow more smoothly, and gas energy dissipation can be reduced. This is more conducive to implementing pressurization on the air, and is conducive to improving air outlet performance of the centrifugal fan.

[0015] In addition, a part at which the second guide surface is connected to the air outlet is the second plane, which is conducive to expanding an opening of the air outlet, and also conducive to improving air outlet performance of the centrifugal fan.

[0016] In a possible implementation, the second arc-shaped surface and the first guide surface are connected to together form an arched surface curving toward the impeller, and have good smoothness, so that the airflow can implement smooth transition from a gradually decreasing channel formed between the first guide surface and the circumferential side surface to a pressurization region channel formed between the second guide surface and the circumferential side surface, impact of a width size change on the airflow is further reduced, and pressurization effect on the airflow can also be ensured. This helps improve air outlet and noise reduction performance of the centrifugal fan.

[0017] In a possible implementation, the convex surface further includes a first plane connected to the other end of the first arc-shaped surface, and the first plane is connected to the air outlet; and from one end at which the first plane is connected to the first arc-shaped surface to one end at which the first plane is connected to the air outlet, the first plane is inclined outward from the cavity, so that a position of the outlet is open, and an opening of the air outlet can be further increased. This helps improve air outlet performance of the centrifugal fan.

[0018] In a possible implementation, the housing includes a side wall, and a bottom wall and a top wall that are provided opposite to each other; and the side wall is located between the bottom wall and the side wall, the side wall, the bottom wall, and the top wall together enclose the cavity, at least one of the bottom wall and the top wall is provided with the air inlet, the side wall is provided with the air outlet, and an inner surface of the side wall forms the inner side surface of the cavity. The housing is formed by assembling the bottom wall, the side wall, and the top wall. This helps improve flexibility of housing assembly and forming, and facilitates production implementation.

[0019] In a possible implementation, the impeller includes a hub and a plurality of fan blades, one end of the plurality of fan blades is fastened to the hub, and an end surface of the other end of the plurality of fan blades is flush with the circumferential side surface of the impeller. The plurality of fan blades help increase an airflow rate of the centrifugal fan, and improve heat dissipation performance of the centrifugal fan.

[0020] A second aspect of embodiments of this application provides an air cooling system. The air cooling system is configured to dissipate heat for a heat generation device, and includes a heat dissipation apparatus, a heat transfer apparatus, and the centrifugal fan according to any one of the foregoing implementations. The heat dissipation apparatus is located at an outlet of the centrifugal fan, the heat dissipation apparatus is connected to the heat transfer apparatus, and the heat transfer apparatus is configured to be connected to the heat generation device. The centrifugal fan is included, so that the centrifugal fan can achieve an objective of noise reduction when meeting a requirement of not deteriorating noise while improving air outlet performance, and can achieve effect of improving heat dissipation performance of the centrifugal fan and reducing noise of the centrifugal fan, thereby implementing high heat dissipation and low noise performance of the air cooling system. A sufficient heat dissipation capability can be well provided for the electronic device, so that performance of the electronic device is well released, thereby helping improve performance and noise reduction experience of the electronic device.BRIEF DESCRIPTION OF DRAWINGS

[0021] FIG. 1 is a diagram of a structure of an electronic device according to an embodiment of this application; FIG. 2 is a diagram of a cross-sectional structure of the electronic device in FIG. 1 along an A-A surface; FIG. 3 is a diagram of a structure of an air cooling system in an electronic device according to an embodiment of this application; FIG. 4 is a diagram of an internal structure of a centrifugal fan in a related technology; FIG. 5 is a diagram of a structure of a centrifugal fan according to an embodiment of this application; FIG. 6 is a diagram of a split structure of a centrifugal fan according to an embodiment of this application; FIG. 7 is a diagram of a structure of an impeller according to an embodiment of this application; FIG. 8 is a diagram of an internal structure of a centrifugal fan according to an embodiment of this application; FIG. 9 is a front view diagram of an internal structure of a centrifugal fan according to an embodiment of this application; FIG. 10 is a simulation diagram of a velocity field of a centrifugal fan in a related technology; and FIG. 11 is a simulation diagram of a velocity field of a centrifugal fan according to an embodiment of this application. Reference numerals:

[0022] 100: electronic device; 101: first external housing; 101a: housing cover; 101b: bottom housing; 1011: air vent; 102: second external housing; 103: heat generation device; 104: air cooling system; 10: centrifugal fan; 11: housing; 11a: bottom wall; 11b: side wall; 11c: top wall; 111: cavity; 112: inner side surface; 1121: convex surface; 1121a: first arc-shaped surface; 1121b: first plane; 1122: first guide surface; 1123: second guide surface; 1123a: second arc-shaped surface; 1123b: second plane; 113: air inlet; 114: air outlet; 115: airflow channel; 12: impeller; 121: circumferential side surface; 122: hub; 123: fan blade; 20: heat dissipation apparatus; 30: heat transfer apparatus; 105: circuit board; 106: button structure; 107: touch region; 108: display; 109: accommodating cavity; 110: power button. DESCRIPTION OF EMBODIMENTS

[0023] Terms used in implementations of this application are merely used to explain specific embodiments of this application, but are not intended to limit this application.

[0024] An electronic device provided in embodiments of this application may include but is not limited to a mobile phone, a tablet computer, a notebook computer, a two-in-one tablet / computer, an ultra-mobile personal computer (ultra-mobile personal computer, UMPC), a handheld computer, an intercom, a netbook, a POS machine, a personal digital assistant (personal digital assistant, PDA), a wearable device, a virtual reality (virtual reality, VR for short) device, an augmented reality (augmented reality, AR for short) device, a router, a power bank, mobile Wi-Fi, and an electronic device that has a heat dissipation requirement, for example, a vehicle-mounted device.

[0025] For example, in embodiments of this application, an example in which the electronic device is a notebook computer is used to describe the electronic device provided in embodiments of this application.

[0026] FIG. 1 is a diagram of a structure of an electronic device according to an embodiment of this application.

[0027] Refer to FIG. 1. The electronic device 100 may include two housings, for example, a first external housing 101 and a second external housing 102 respectively, and the electronic device 100 may further include a rotating mechanism (not shown in the figure). The first external housing 101 and the second external housing 102 are respectively located on two sides of the rotating mechanism, the first external housing 101 and the second external housing 102 may be separately connected to the rotating mechanism, and the rotating mechanism may implement rotating cooperation between the first external housing 101 and the second external housing 102, to implement opening and closing of a notebook computer.

[0028] The electronic device 100 may further include a button structure 106. The button structure 106 may be disposed on the first external housing 101. The button structure 106 may be configured to: identify operation information of a user, implement human-machine interaction with the user, and the like.

[0029] It should be understood that the button structure 106 may be a protruding button mechanical part, or the button structure 106 may be a virtual button or the like.

[0030] The first external housing 101 may further have a touch region 107, and the touch region 107 may also be used to identify operation information of the user, for example, gesture information, to enrich operation experience on the electronic device 100.

[0031] The first external housing 101 may further have a power button 110, and the power button 110 is configured to enable or disable the electronic device.

[0032] The electronic device 100 may further include a display 108. The display 108 may be disposed on the second external housing 102, and the display 108 is configured to display an image and the like.

[0033] Certainly, in some other examples, the display 108 may also be configured to identify operation information of the user, for example, operation position information and gesture information of the user.

[0034] The display 108 may include a display panel. The display panel may be a liquid crystal display (liquid crystal display, LCD for short), an organic light-emitting diode (organic light-emitting diode, OLED for short), an active matrix organic light-emitting diode or an active matrix organic light-emitting diode (active matrix organic light-emitting diode, AMOLED for short), a flexible light-emitting diode (flex light-emitting diode, FLED for short), a mini-LED, a micro-LED, a micro-OLED, a quantum dot light-emitting diode (quantum dot light-emitting diode, QLED for short), and the like.

[0035] The first external housing 101 may have an accommodating cavity, and a structural component of the electronic device may be accommodated in the accommodating cavity. In some examples, the second external housing 102 may also have an accommodating cavity, and the accommodating cavity of the second external housing 102 may also be configured to accommodate the structural component of the electronic device.

[0036] FIG. 2 is a diagram of a cross-sectional structure of the electronic device in FIG. 1 along an A-A surface.

[0037] Refer to FIG. 2. The first external housing 101 is used as an example. The first external housing 101 may include a bottom housing 101b and a housing cover 101a. The housing cover 101a may be disposed on the bottom housing 101b. The housing cover 101a and the bottom housing 101b together enclose the accommodating cavity 109. The structural component of the electronic device is fastened into the accommodating cavity 109.

[0038] The button structure 106, the touch region 107, the power button 110, and the like may be separately located on the housing cover 101a of the first external housing 101.

[0039] For example, the electronic device 100 may further include a processor (not shown in the figure). For example, the processor may include a central processing unit (central processing unit, CPU for short), an application processor (application processor, AP for short), a modem processor, a graphics processing unit (graphics processing unit, GPU for short), an image signal processor (image signal processor, ISP for short), a controller, a video codec, a digital signal processor (digital signal processor, DSP for short), a baseband processor, a neural-network processing unit (neural-network processing unit, NPU for short), and / or the like.

[0040] The processor may generate an operation control signal based on instruction operation code and a time sequence signal, to complete control of instruction fetching and instruction execution. A memory may be further disposed in the processor to store instructions and data.

[0041] The processor may include one or more interfaces. The processor may be connected to another component of the electronic device 100 through the interface. For example, the processor is connected to a module such as a sensor, an audio module, a display, or a camera of the electronic device 100.

[0042] For example, the processor may include a universal serial bus (universal serial bus, USB for short) interface (not shown in the figure). The USB interface may be provided on the first external housing 101, and may be configured to be connected to the electronic device and a peripheral device.

[0043] For example, the USB interface may be configured to be connected to a charger, to implement charging of the electronic device 100 through the charger. The USB interface may also be configured to be connected to another electronic device, for example, a storage device, to implement data transmission between the electronic device 100 and the another electronic device.

[0044] Certainly, in some other examples, the USB interface may also be configured to be connected to another electronic device, for example, may be configured to be connected to an external projection device or a VR device.

[0045] The electronic device 100 may further include a battery, a charging module, a power management module, and the like. The charging module is configured to receive a charging input of the charger, to charge the battery. For example, the charging management module may receive the charging input of the charger through the USB interface.

[0046] The power management module is configured to be connected to the battery, the charging management module, and the processor. When charging the battery, the charging management module may further supply power to the electronic device 100 through the power management module. The power management module receives an input of the battery and / or the charging management module, and may supply power to the processor, the memory, the display, the camera, and the like.

[0047] The power management module may be further configured to monitor the battery, for example, monitor parameters such as a battery capacity, a battery cycle count, and a battery health status (electric leakage or impedance).

[0048] The electronic device 100 may further include the camera (not shown in the figure), and an image shooting function may be implemented through the camera.

[0049] The electronic device 100 may further include an audio module, a speaker, a microphone, and the like (not shown in the figure), to implement an audio function of the electronic device 100. The audio module is configured to convert digital audio information into an analog audio signal output, and is also configured to convert an analog audio input into a digital audio signal. The audio module may be further configured to encode and decode an audio signal. In some embodiments, the audio module may be disposed in the processor, or a part of functional modules of the audio module are disposed in the processor.

[0050] The speaker, also referred to as a "loudspeaker", is configured to convert an audio electrical signal into a sound signal. The electronic device 100 may output a sound through the speaker, to play the sound. The microphone, also referred to as a "mike" or a "mic", is configured to convert a sound signal into an electrical signal. The electronic device 100 may receive an external sound through the microphone.

[0051] It may be understood that the structure shown in embodiments of this application does not constitute a specific limitation on the electronic device. In some other embodiments of this application, the electronic device may include more or fewer structural components than those shown in the figure, or combine some structural components, or split some components, or have different component arrangements.

[0052] For example, the electronic device 100 may further include a pressure sensor, a touch sensor, an antenna, a communication module, and the like.

[0053] Still refer to FIG. 2. The electronic device may further include a circuit board 105, a heat generation device 103 may be disposed on the circuit board 105, and both the heat generation device 103 and the circuit board 105 may be fastened into the accommodating cavity. The heat generation device 103 may be any device that generates heat during operation and that needs to dissipate heat, for example, may be the foregoing processor or battery.

[0054] It may be understood that the electronic device 100 may include one or more heat generation devices 103, and a specific quantity and types of heat generation devices 103 may be selected and specified as required.

[0055] To implement heat dissipation of the heat generation device 103, heat dissipation of the electronic device 100 may be implemented in an air cooling heat dissipation manner. For example, as shown in FIG. 2, the electronic device may further include an air cooling system 104, and the air cooling system 104 may implement heat dissipation of the electronic device.

[0056] The air cooling system 104 may include a centrifugal fan 10. The centrifugal fan 10 may be disposed near the heat generation device 103. The centrifugal fan 10 can accelerate air flowing in a surrounding environment (for example, in the accommodating cavity), and quickly exchange heat with the heat generation device 103, thereby implementing heat dissipation effect for heat of the heat generation device 103.

[0057] For example, the centrifugal fan 10 may be electrically connected to the circuit board 105, and the circuit board 105 can drive and control the centrifugal fan 10.

[0058] In some examples, an air vent 1011 may be further provided on the first external housing 101. For example, the air vent 1011 may be provided on a side wall of the bottom housing 101b, and the air vent 1011 may penetrate the side wall of the bottom housing 101b, so that the air vent 1011 can communicate with the accommodating cavity, that is, the accommodating cavity communicates with an external environment of the electronic device through the air vent 1011, thereby implementing air circulation inside and outside the electronic device, and further improving the heat dissipation effect.

[0059] It should be noted that FIG. 2 shows only one air vent 1011 provided on the first external housing 101. To implement air circulation inside and outside the electronic device, there may be a plurality of air vents 1011 on the first external housing 101. For example, there may be two air vents. One air vent may be used as an air inlet, and the other air vent may be used as an air outlet.

[0060] FIG. 3 is a diagram of a structure of an air cooling system in an electronic device according to an embodiment of this application.

[0061] Refer to FIG. 3. The air cooling system 104 may further include a heat dissipation apparatus 20 and a heat transfer apparatus 30. The heat transfer apparatus 30 may be configured to implement high-performance heat transfer between a heat generation device 103 and the heat dissipation apparatus 20.

[0062] In some examples, the heat transfer apparatus 30 may be an apparatus with high heat transfer performance, for example, a vapor chamber (vapor chamber, VC for short) or a heat pipe.

[0063] The heat dissipation apparatus 20 may be configured to provide a heat exchange site for a centrifugal fan 10 and the heat transfer apparatus 30, to implement more enhanced heat exchange effect. In some examples, the heat dissipation apparatus 20 may be an enhanced heat exchange apparatus such as a plain plate-fin heat sink or a pin-fin heat sink.

[0064] The heat dissipation apparatus 20 may be located at an air outlet 114 of the centrifugal fan 10, the heat transfer apparatus 30 may be located between the heat dissipation apparatus 20 and the heat generation device 103, and the heat transfer apparatus 30 may be separately in thermal contact with the heat dissipation apparatus 20 and the heat generation device 103, so that heat can be transferred between the heat generation device 103, the heat transfer apparatus 30, and the heat dissipation apparatus 20.

[0065] Heat generated by the heat generation device 103 may be efficiently conducted to the heat dissipation apparatus 20 through the heat transfer apparatus 30. When the centrifugal fan 10 runs, flowing of cold air may be accelerated, so that a high-speed airflow may be generated at the air outlet 114, and the high-speed airflow can pass through the heat dissipation apparatus 20, to implement heat exchange with the heat dissipation apparatus 20, and absorb heat in the heat dissipation apparatus 20 to form a hot airflow. The hot airflow may bring the heat to an environment outside the electronic device. For example, the hot airflow may be exhausted to the outside of the electronic device through an air vent on a bottom housing, to implement heat dissipation for the electronic device.

[0066] As requirements for performance of electronic devices are continuously improved, power consumption and heat dissipation are also continuously deteriorated. Heat of the electronic devices needs to be evacuated to an environment in a timely manner. Heat dissipation performance of air cooling systems in an air cooling manner greatly depends on fans, and high heat dissipation effect becomes one of main performance requirements pursued by the centrifugal fan. In addition, along with close integration of the electronic devices into people's daily life, noise of the fans also greatly affects use experience of the devices. Therefore, how to improve performance of centrifugal fans and reduce noise of the centrifugal fans is a key to improve capabilities of the air cooling systems in the air cooling manner.

[0067] FIG. 4 is a diagram of an internal structure of a centrifugal fan in a related technology.

[0068] Refer to FIG. 4. The common centrifugal fan 200 may include a fan blade 201 and a volute 202. The volute 202 has a cavity 202a, the fan blade 201 is disposed in the cavity 202a, and there is a gap between the fan blade 201 and an inner surface of a side wall of the volute 202, to form an airflow channel 203, that is, there is the airflow channel between the fan blade 201 and the inner surface of the side wall of the volute 202. The volute 202 may be separately provided with an air inlet (not shown in the figure) and an air outlet 202b, and the air inlet and the air outlet 202b may separately communicate with the airflow channel 203.

[0069] The fan blade 201 is rotatably disposed in the cavity 202a of the volute 202, the fan blade 201 can rotate, so that an airflow can be quickly exhausted from the air outlet through the air inlet and the airflow channel 203, and air flowing in an environment can be improved through the centrifugal fan 200. An arrow in FIG. 4 shows a flow direction of the airflow when the fan blade 201 rotates counterclockwise.

[0070] To improve performance of the centrifugal fan 200, a protruding volute tongue 204 may be disposed on the inner surface of the side wall of the volute 202, and the volute tongue 204 may be located at a position, on the inner surface of the side wall, near the air outlet 202b. Because the inner surface of the side wall protrudes to form the volute tongue 204, a distance between an outer surface of the volute tongue 204 and a circumferential side surface of the fan blade 201 is narrow, that is, the volute tongue 204 may be a part, on the inner surface of the side wall of the volute 202, closest to the fan blade 201, and the airflow channel 203 located between the volute tongue 204 and the fan blade 201 becomes narrow.

[0071] From a position of the volute tongue 204 to the air outlet 202b, the airflow channel 203 has a region that gradually increases from narrow to wide, for example, a pressurization region 202c in FIG. 4. When the airflow passes through the region from narrow to wide, the airflow may be pressurized to increase an airflow rate of the fan.

[0072] In addition, the protruding volute tongue 204 can further form a physical partition between the pressurization region 202c and a region of the air outlet 202b, to prevent air of the air outlet 202b of the fan from being brought into the pressurization region 202c by rotation of the fan blade 201, causing deterioration of air outlet performance of the fan.

[0073] Extensive structural design experience indicates that a smaller gap between the volute tongue and the circumferential side surface of the fan blade indicates a higher airflow rate of the centrifugal fan 200 and better heat dissipation performance. However, the narrower a width of the airflow channel at the volute tongue, the more intense a pressure pulsation of air is formed in the rapidly narrowing channel when each fan blade rotates and brushes through the channel, to generate a large amount of noise. Therefore, a smaller gap between the volute tongue and the circumferential side surface of the fan blade indicates greater noise of the centrifugal fan. It is difficult to ensure that the noise is not deteriorated when the heat dissipation performance of the centrifugal fan is improved.

[0074] In view of this, embodiments of this application provide a centrifugal fan, so that an objective of noise reduction when meeting a requirement of not deteriorating noise while improving air outlet performance of the centrifugal fan can be implemented, and effect of improving heat dissipation performance of the centrifugal fan and reducing noise of the centrifugal fan can be achieved. The centrifugal fan can provide a sufficient heat dissipation capability for the electronic device, to support release of performance of the electronic device, thereby helping improve performance of the electronic device, and enabling a user to have good heat dissipation / noise reduction experience.

[0075] FIG. 5 is a diagram of a structure of a centrifugal fan according to an embodiment of this application.

[0076] Refer to FIG. 5. The centrifugal fan 10 may include a housing 11 and an impeller 12. The housing 11 is used as a main bearing mechanical part of the centrifugal fan 10. The housing 11 may have a cavity 111 configured to accommodate the impeller 12, or may be configured to accommodate another mechanical part of the centrifugal fan 10.

[0077] An air inlet 113 and an air outlet 114 are provided on the housing 11. The air inlet 113 and the air outlet 114 may be through holes on the housing 11 respectively. The air inlet 113 may communicate with the cavity 111 in the housing 11, and the air outlet 114 may also communicate with the cavity 111 in the housing 11.

[0078] It should be noted that in this embodiment of this application, a formed material of the housing 11 is not limited. For example, the formed material of the housing 11 may be plastic, metal, alloy, or the like.

[0079] An assembly and forming manner of the housing 11 is not limited either. For example, the housing 11 may be a mechanical part that is integrally formed. For example, the housing 11 may be a mechanical part that is integrally formed in a manner such as injection forming.

[0080] Alternatively, in some examples, the housing 11 may be formed by assembling a split mechanical part. A specific material and an assembly manner may be selected and specified based on an actual requirement.

[0081] In this embodiment of this application, an example in which the housing 11 is formed by assembling the split mechanical part is used for description. The housing 11 is formed by assembling the split mechanical part, and has high design flexibility. This helps reduce production design difficulty and facilitate implementation.

[0082] FIG. 6 is a diagram of a split structure of a centrifugal fan according to an embodiment of this application.

[0083] For example, with reference to FIG. 5 and FIG. 6, the housing 11 may include a bottom wall 11a, a side wall 11b, and a top wall 11c. The top wall 11c and the bottom wall 11a may be provided opposite to each other, and the side wall 11b may be located between the bottom wall 11a and the top wall 11c. In this way, the top wall 11c, the side wall 11b, and the bottom wall 11a may together enclose the cavity 111 of the housing 11, and an inner surface (facing a box) of the side wall 11b may form an inner side surface 112 of the cavity 111.

[0084] The bottom wall 11a and the top wall 11c may be planes respectively, the side wall 11b is located between the bottom wall 11a and the top wall 11c, and the side wall 11b may have a specific extension height in a direction perpendicular to the bottom wall 11a and the top wall 11c, to ensure that the bottom wall 11a, the top wall 11c, and the side wall 11b can form the cavity 111.

[0085] At least one of the top wall 11c or the bottom wall 11a may be provided with the air inlet 113, and the side wall 11b may be provided with the air outlet 114, that is, the air outlet 114 is located between the top wall 11c and the bottom wall 11a.

[0086] It should be noted that there may be one air inlet 113, for example, as shown in FIG. 5 and FIG. 6, and a through hole may be provided on the top wall 11c to form the air inlet 113.

[0087] Certainly, in some other examples, there may alternatively be a plurality of air inlets 113. For example, there may be two air inlets. For example, through holes may be respectively provided on the top wall 11c and the bottom wall 11a to form two air inlets.

[0088] In this embodiment of this application, an example in which one air inlet 113 is provided on the top wall 11c is used for description.

[0089] The impeller 12 may be rotatably disposed in the cavity 111 enclosed by the bottom wall 11a, the side wall 11b, and the top wall 11c. The impeller 12 may rotate around an axis o (as shown in FIG. 7), and a direction parallel to the axis is an axial direction of the impeller 12.

[0090] A shape of the impeller 12 may be a circle, and the axis of the impeller 12 may be a straight line that passes through a center of the impeller 12 and is perpendicular to the impeller 12. In this embodiment of this application, a radial direction is a direction parallel to a diameter / radius of the impeller 12, and the axial direction of the impeller 12 may be perpendicular to the radial direction. It may be understood that the radial direction may be any direction (for example, a y direction in FIG. 7) that passes through the center of the impeller 12 and is perpendicular to the axial direction of the impeller 12, and the radial direction may include a plurality of directions.

[0091] The air inlet 113 on the housing 11 may be located on one side of the impeller 12 in the axial direction, and the air outlet 114 may be located on one side of the impeller 12 in the radial direction (refer to FIG. 5).

[0092] FIG. 7 is a diagram of a structure of an impeller according to an embodiment of this application.

[0093] Refer to FIG. 7. The impeller 12 may include a circumferential side surface 121, and the circumferential side surface 121 may be an outermost surface of the impeller 12 in a circumferential direction. It may also be understood as that the circumferential side surface 121 is a circumferential surface formed by using an axis o of the impeller 12 as a center line and using a radius of the impeller 12 as a radius.

[0094] The impeller 12 may include a hub 122 and a plurality of fan blades 123. The plurality of fan blades 123 may be fastened to the hub 122, and the hub 122 may drive the plurality of fan blades 123 to rotate, so that the impeller 12 rotates.

[0095] The plurality of fan blades 123 may be distributed on the hub 122 in an array around the axis o, and the plurality of fan blades 123 may be arranged at an equal gap. The plurality of fan blades 123 help increase an airflow rate of a centrifugal fan 10, and improve heat dissipation performance of the centrifugal fan 10.

[0096] A shape of the hub 122 may be a circle, and the fan blades 123 may be approximately in an arc-shaped plate structure. One end of the plurality of fan blades 123 may be fastened to the hub 122, and an end surface of the other end may be flush with the circumferential side surface 121 of the impeller 12.

[0097] A specific quantity of fan blades 123 is not limited in this embodiment of this application, and may be specifically selected and specified based on an actual requirement.

[0098] The impeller 12 may further include an annular reinforcing member 124. The annular reinforcing member 124 is fastened to one end, of the plurality of fan blades 123, facing away from the hub 122, and the plurality of fan blades 123 are connected and fastened into a whole mechanical part through the reinforcing member 124, which is conducive to reinforcing strength of the fan blades 123, and improving stability of the entire impeller 12. An outer side surface of the annular reinforcing member 124 in the circumferential direction may be flush with the circumferential side surface 121 of the impeller 12. In some examples, the outer side surface of the annular reinforcing member 124 in the circumferential direction and an end surface of the other end, of the plurality of fan blades 123, facing away from the hub 122 may together form the circumferential side surface 121 of the impeller 12.

[0099] The centrifugal fan 10 may further include a drive structure (not shown in the figure). For example, the drive structure may be fastened to the hub 122, and the drive structure is connected to the hub 122 and drives the hub 122 to rotate, so that the hub 122 drives the plurality of fan blades 123 to rotate together.

[0100] FIG. 8 is a diagram of an internal structure of a centrifugal fan according to an embodiment of this application. It should be noted that a top wall of the centrifugal fan is not shown in FIG. 8.

[0101] Refer to FIG. 8. An impeller 12 is rotatably assembled in a cavity 111, and there is a gap between a circumferential side surface 121 of the impeller 12 and an inner side surface 112 (namely, an inner surface of a side wall 11b) of the cavity 111, to form an airflow channel 115. The airflow channel 115 separately communicates with an air outlet 114 on the side wall 11b and an air inlet on the top wall.

[0102] Air flowing in the airflow channel 115 can be accelerated by rotating the impeller 12, so that air outside the cavity 111 can quickly enter from the air inlet, and is exhausted from the air outlet 114 at a high speed after passing through the airflow channel 115.

[0103] A rotation direction of the impeller 12 may be clockwise rotation, or a rotation direction of the impeller 12 may be counterclockwise rotation.

[0104] FIG. 9 is a front view diagram of an internal structure of a centrifugal fan according to an embodiment of this application.

[0105] With reference to FIG. 9, an inner side surface 112 of a cavity 111 may include a convex surface 1121, a first guide surface 1122, and a second guide surface 1123.

[0106] One end of the convex surface 1121 is connected to one end of an air outlet 114, the other end of the convex surface 1121 is connected to one end of the first guide surface 1122, and an intersection line (refer to the intersection line L1 in FIG. 8) may be formed at a position at which the convex surface 1121 is connected to the first guide surface 1122.

[0107] The other end of the first guide surface 1122 is connected to one end of the second guide surface 1123, and an intersection line (refer to the intersection line L2 in FIG. 8) may be formed at a position at which the first guide surface 1122 is connected to the second guide surface 1123. The other end of the second guide surface 1123 is connected to the other end of the air outlet 114.

[0108] A distance between the intersection line L1 between the convex surface 1121 and the first guide surface 1122 and a circumferential side surface 121 of the impeller 12 in a radial direction is a first distance, and may be used as a radial line (a straight line, in the radial direction, passing through a center) that separately intersects an axis o and the intersection line L1. For example, the radial line may be perpendicular to the axis o and the intersection line L1, and the first distance may be a length of a line segment between an intersection point between the radial line and the circumferential side surface 121 of the impeller 12 and an intersection point between the radial line and the intersection line L1.

[0109] For example, FIG. 9 is a front view diagram of the centrifugal fan 10. Projecting a structure of the centrifugal fan to a bottom wall 11a is used as an example. A projection of the axis of the impeller 12 on the bottom wall 11a is o1, a projection of the intersection line L1 between the convex surface 1121 and the first guide surface 1122 on the bottom wall 11a is a point o2, a radial line passing through the projection point o1 of the connection axis and the projection o2 of the intersection line L1 is y1, and the first distance d1 is a length of a line segment between an intersection point between the radial line y1 and the circumferential side surface 121 of the impeller 12 and an intersection point between the radial line y1 and the projection point o2 of the intersection line.

[0110] Correspondingly, a distance between the intersection line L2 between the first guide surface 1122 and the second guide surface 1123 and the circumferential side surface 121 of the impeller 12 in a radial direction is a second distance, and may be used as a radial line that separately intersects the axis o and the intersection line L2. For example, the radial line may be perpendicular to the axis o and the intersection line L2, and the second distance may be a length of a line segment between an intersection point between the radial line and the circumferential side surface 121 of the impeller 12 and an intersection point between the radial line and the intersection line L2.

[0111] For example, as shown in FIG. 9, projecting the structure of the centrifugal fan to the bottom wall 11a is used as an example. A projection of the intersection line between the first guide surface 1122 and the second guide surface 1123 on the bottom wall 11a is a point o3, a radial line passing through the projection point o1 of the connection axis and the projection point o3 of the intersection line L2 is y2, and the second distance d2 is a length of a line segment between an intersection point between the radial line y2 and the circumferential side surface 121 of the impeller 12 and an intersection point between the radial line y2 and the projection o3 of the intersection line.

[0112] It may be understood that the radial line y1 and the radial line y2 respectively correspond to two different radial directions, the two radial directions may intersect, and there is an included angle between the two radial directions.

[0113] The second distance d2 is less than the first distance d1. To be specific, a distance between the intersection line L2 between the second guide surface 1123 and the first guide surface 1122 and the circumferential side surface 121 is less than a distance between the intersection line L1 between the convex surface 1121 and the first guide surface 1122 and the circumferential side surface 121. It may be understood that the convex surface 1121 may be formed by protruding from the inner side surface 112 of the cavity 111, and the convex surface 1121 protrudes into the cavity 111, which causes a sudden size change of a width (a width in the radial direction) of the airflow channel 115 at a position of the convex surface 1121, in other words, in a direction from the convex surface 1121 to the second guide surface 1123, the airflow channel 115 undergoes a width change from wide to narrow once at the position of the convex surface 1121, and the airflow channel 115 undergoes a width change from wide to narrow twice at a position of the first guide surface 1122.

[0114] With reference to FIG. 8 and FIG. 9, from one end at which the second guide surface 1123 is connected to the first guide surface 1122 to the end at which the second guide surface 1123 is connected to the air outlet 114, a distance between the second guide surface 1123 and the circumferential side surface 121 of the impeller 12 in a radial direction may gradually increase. In other words, starting from the end (for example, the intersection line L2) at which the second guide surface 1123 is connected to the first guide surface 1122, the airflow channel 115 has a region whose width gradually increases from narrow to wide. The region may be used as a pressurization region of the centrifugal fan, for example, a pressurization region 10a shown in FIG. 9. When an airflow passes through the region whose width gradually increases from narrow to wide, the airflow is pressurized to increase an airflow rate of the fan.

[0115] Still refer to FIG. 9. In other words, a minimum distance between the inner side surface 112 of the cavity 111 and an inner surface of the impeller 12 in the radial direction is located at a position of the intersection line between the second guide surface 1123 and the first guide surface 1122, a narrowest position of the width of the airflow channel 115 is located at a position at which the second guide surface 1123 and the first guide surface 1122 are connected, and the narrowest position of the width of the airflow channel 115 is far away from the convex surface 1121 (a position at which a sudden size change occurs). In comparison with that in a related technology, the second distance d2 may be small under a same noise requirement (for example, under a condition of a same distance between the convex surface and the circumferential side surface), so that the centrifugal fan can have a stronger pressurization capability, and air outlet performance of the centrifugal fan is stronger. This helps improve heat dissipation performance of the centrifugal fan, and ensures that the noise is not deteriorated when the heat dissipation performance is improved.

[0116] In addition, because the second distance d2 is less than the first distance d1, a width change between the convex surface 1121 and the circumferential side surface 121 of the impeller 12 has small impact on the performance of the centrifugal fan 10. Therefore, in comparison with that in the related technology, the first distance d1 may be large, and a change rate of a cross-sectional area from a position of the air outlet 114 to the convex surface 1121 is reduced. When the impeller 12 rotates and passes through the position of the convex surface 1121, a sudden size change at the position may be reduced to some extent, so that a pressure pulsation generated at the position of the convex surface 1121 is reduced, noise is reduced, and noise reduction of the centrifugal fan can be implemented. This can consider both performance improvement and noise reduction of the fan to some extent, to implement both performance improvement and noise reduction of the centrifugal fan.

[0117] Still refer to FIG. 9. From one end at which the first guide surface 1122 is connected to the convex surface 1121 to the end at which the first guide surface 1122 is connected to the second guide surface 1123, a distance between the first guide surface 1122 and the circumferential side surface 121 of the impeller 12 in a radial direction gradually decreases, that is, a channel whose width gradually decreases is formed in a direction from the convex surface 1121 to the second guide surface 1123.

[0118] In other words, a channel that gradually decreases is disposed between the convex surface 1121 and the pressurization region formed between the second guide surface 1123 and the circumferential side surface 121, which facilitates reduction of the second distance compared with the first distance, has high transition smoothness, reduces noise caused by a width change, and the like. This helps further implement noise reduction under the condition of improving performance of the centrifugal fan 10.

[0119] For example, from one end at which the first guide surface 1122 is connected to the convex surface 1121 to the end at which the first guide surface 1122 is connected to the second guide surface 1123, a distance between the first guide surface 1122 and the circumferential side surface 121 of the impeller 12 in the radial direction may gradually monotonically decrease. This helps reduce structural design difficulty of the first guide surface 1122 and facilitates design and production implementation under a condition of gradually decreasing the distance between the first guide surface 1122 and the circumferential side surface 121 of the impeller 12.

[0120] The first guide surface 1122 may be an arched surface curving toward the impeller 12, so that the first guide surface 1122 is an arched surface and has good smoothness. This facilitates smooth transition of an airflow in a gradually decreasing channel formed between the first guide surface 1122 and the circumferential side surface 121, so that impact of a width size change on the airflow can be reduced, thereby helping improve air outlet and noise reduction performance of the centrifugal fan 10.

[0121] Still refer to FIG. 9. The convex surface 1121 may include a first arc-shaped surface 1121a and a first plane 1121b. One end of the first arc-shaped surface 1121a may be connected to the first guide surface 1122, the first arc-shaped surface 1121a may be an arched surface protruding into the impeller 12, and the first arc-shaped surface 1121a is connected to the first guide surface 1122 to form a curved surface. This helps improve smoothness of a connection between the first arc-shaped surface 1121a and the arc-shaped first guide surface 1122, and reduces impact of a width size change on the airflow.

[0122] The intersection line between the convex surface 1121 and the first guide surface 1122 is an intersection line between the first arc-shaped surface 1121a that is convex and the first guide surface 1122 that is concave, and the first arc-shaped surface 1121a is connected to the first guide surface 1122 to form a curved surface, a straight line that passes through a concave-convex inflection point of a curve of the curved surface and is perpendicular to the radial direction is the intersection line between the first arc-shaped surface 1121a and the first guide surface 1122. As shown in FIG. 9, a projection, on the bottom wall 11a, of the curved surface formed by the first arc-shaped surface 1121a that is convex and the first guide surface 1122 that is concave is the curve of the curved surface, and the concave-convex inflection point of the curve is a point o2, the straight line that passes through the inflection point o2 and is perpendicular to the radial direction is the intersection line (L1 in FIG. 8) between the convex surface 1121 and the first guide surface 1122.

[0123] The other end of the first arc-shaped surface 1121a may be connected to one end of the first plane 1121b, the other end of the first plane 1121b may be connected to one end of the air outlet 114, and a smooth transition connection may be implemented between the other end of the first arc-shaped surface 1121a and the end of the first plane 1121b.

[0124] The first plane 1121b may be an inclined plane. Specifically, from one end at which the first plane 1121b is connected to the first arc-shaped surface 1121a to one end at which the first plane 1121b is connected to the air outlet 114, the first plane 1121b is inclined outward from the cavity 111, so that a position of the air outlet 114 may be open, and an opening of the air outlet 114 can be further increased. This helps improve air outlet performance of the centrifugal fan.

[0125] Still refer to FIG. 9. The second guide surface 1123 may include a second arc-shaped surface 1123a and a second plane 1123b. One end of the second arc-shaped surface 1123a is connected to the first guide surface 1122, the other end of the second arc-shaped surface 1123a is connected to one end of the second plane 1123b, a smooth transition connection may be implemented between the other end of the second arc-shaped surface 1123a and the end of the second plane 1123b, and the other end of the second plane 1123b is connected to the other end of the air outlet 114. Starting from the end at which the second guide surface 1123 is connected to the first guide surface 1122, a width of the airflow channel 115 gradually increases from narrow to wide and may be used as a pressurization region. A part at which the second guide surface 1123 is connected to the first guide surface 1122 is the second arc-shaped surface 1123a, so that air in the pressurization region can flow more smoothly, and gas energy dissipation can be reduced. This is more conducive to implementing pressurization on the air, and is conducive to improving air outlet performance of the centrifugal fan.

[0126] In addition, a part at which the second guide surface 1123 is connected to the air outlet 114 is the second plane 1123b, which is conducive to expanding an opening of the air outlet 114, and also conducive to improving air outlet performance of the centrifugal fan.

[0127] The first guide surface 1122 and the second guide surface 1123 are connected to together form an arched surface curving toward the impeller 12, and have good smoothness, so that the airflow can implement smooth transition from a gradually decreasing channel formed between the first guide surface 1122 and the circumferential side surface 121 to a pressurization region channel formed between the second guide surface 1123 and the circumferential side surface 121, impact of a width size change on the airflow is further reduced, and pressurization effect on the airflow can also be ensured. This helps improve air outlet and noise reduction performance of the centrifugal fan.

[0128] FIG. 10 is a simulation diagram of a velocity field of a centrifugal fan in a related technology. FIG. 11 is a simulation diagram of a velocity field of a centrifugal fan according to an embodiment of this application.

[0129] Simulation is performed on the velocity field of the centrifugal fan 200 in the foregoing related technology in this embodiment and the velocity field of the centrifugal fan 10 in this embodiment of this application. In the related technology, a gap between a volute tongue of the centrifugal fan 200 and a circumferential side surface of a fan blade is equal to a first distance d1 of the centrifugal fan 10 in this embodiment of this application.

[0130] With reference to FIG. 10 and FIG. 11, under a condition that rotation speeds of an impeller are the same, an airflow rate of the centrifugal fan 200 in the related technology is 2.56 cfm, where cfm is an airflow rate unit, which means air volume-cubic feet per minute (cubic feet per minute), and is a volume of air passing through a cross section of an air outlet (or an air inlet) of the fan per unit of time.

[0131] An airflow rate of the centrifugal fan 10 in this embodiment of this application is 2.84 cfm. In other words, under a condition of a same rotation speed, the airflow rate of the centrifugal fan in this embodiment of this application increases by 11%.

[0132] A maximum air outlet velocity of the centrifugal fan 200 in the related technology is 23.28 m / s, where m / s is a wind velocity unit, which means meter per second, and is a distance that air travels. A maximum air outlet velocity of the centrifugal fan 10 in this embodiment of this application is 23.19 m / s, wind velocities are equivalent, and air outlet noise effect of the centrifugal fan is also basically equivalent.

[0133] In conclusion, the centrifugal fan provided in embodiments of this application can significantly increase the airflow rate under a condition of a same noise requirement, and correspondingly can achieve significant noise reduction effect under a condition of a same airflow rate requirement.

[0134] It should be noted that values and value ranges in embodiments of this application are approximate values, and there may be an error within a specific range. A person skilled in the art may consider that the error is negligible.

[0135] In the descriptions of embodiments of this application, it should be noted that unless otherwise clearly specified and limited, the term "installation", "connection to", or "connection" should be understood in a broad sense, for example, may be fastening, or may be an indirect connection through an intermediate medium, or may be internal communication between two elements or an interaction relationship between two elements. A person of ordinary skill in the art may understand specific meanings of the foregoing terms in embodiments of this application based on specific cases. The terms such as "first", "second", "third", "fourth", and the like (if any) are intended to distinguish between similar objects but do not necessarily indicate a specific order or sequence.

[0136] Finally, it should be noted that the foregoing embodiments are merely used to describe the technical solutions in embodiments of this application, but not to limit the technical solutions. Although embodiments of this application are described in detail with reference to the foregoing embodiments, a person of ordinary skill in the art should understand that the technical solutions recorded in the foregoing embodiments may still be modified, or some or all of technical features thereof may be equivalently replaced. However, these modifications or replacements do not depart from the scope of the technical solutions in embodiments of this application.

Examples

Embodiment Construction

[0023]Terms used in implementations of this application are merely used to explain specific embodiments of this application, but are not intended to limit this application.

[0024]An electronic device provided in embodiments of this application may include but is not limited to a mobile phone, a tablet computer, a notebook computer, a two-in-one tablet / computer, an ultra-mobile personal computer (ultra-mobile personal computer, UMPC), a handheld computer, an intercom, a netbook, a POS machine, a personal digital assistant (personal digital assistant, PDA), a wearable device, a virtual reality (virtual reality, VR for short) device, an augmented reality (augmented reality, AR for short) device, a router, a power bank, mobile Wi-Fi, and an electronic device that has a heat dissipation requirement, for example, a vehicle-mounted device.

[0025]For example, in embodiments of this application, an example in which the electronic device is a notebook computer is used to describe the electronic...

Claims

1. A centrifugal fan, comprising a housing (11) and an impeller (12), wherein the housing (11) has a cavity (111), the housing (11) has an air inlet (113) and an air outlet (114), the impeller (12) is rotatably disposed in the cavity (111), a circumferential side surface (121) of the impeller (12) and an inner side surface (112) of the cavity (111) are spaced apart to form an airflow channel (115), and the air outlet (114) and the air inlet (113) separately communicate with the airflow channel (115); the inner side surface (112) of the cavity (111) comprises a convex surface (1121), a first guide surface (1122), and a second guide surface (1123) that are sequentially connected, the convex surface (1121) is connected to one end of the air outlet (114), the second guide surface (1123) is connected to the other end of the air outlet (114), and from one end at which the second guide surface (1123) is connected to the first guide surface (1122) to the end at which the second guide surface (1123) is connected to the air outlet (114), a distance between the second guide surface (1123) and the circumferential side surface (121) of the impeller (12) in a radial direction of the impeller (12) gradually increases; and a distance between an intersection line between the convex surface (1121) and the first guide surface (1122) and the circumferential side surface (121) of the impeller (12) in a radial direction is a first distance, a distance between an intersection line between the first guide surface (1122) and the second guide surface (1123) and the circumferential side surface (121) of the impeller (12) in a radial direction is a second distance, and the second distance is less than the first distance.

2. The centrifugal fan according to claim 1, wherein from one end at which the first guide surface (1122) is connected to the convex surface (1121) to the end at which the first guide surface (1122) is connected to the second guide surface (1123), a distance between the first guide surface (1122) and the circumferential side surface (121) of the impeller (12) in a radial direction gradually decreases.

3. The centrifugal fan according to claim 2, wherein from the end at which the first guide surface (1122) is connected to the convex surface (1121) to the end at which the first guide surface (1122) is connected to the second guide surface (1123), the distance between the first guide surface (1122) and the circumferential side surface (121) of the impeller (12) in the radial direction monotonically decreases.

4. The centrifugal fan according to claim 3, wherein the first guide surface (1122) is an arched surface curving toward the impeller (12); the convex surface (1121) comprises a first arc-shaped surface (1121a), and the first arc-shaped surface (1121a) is an arched surface protruding into the cavity (111); and one end of the first arc-shaped surface (1121a) is connected to the first guide surface (1122) to form a curved surface, and the intersection line between the convex surface (1121) and the first guide surface (1122) is a straight line that passes through a concave-convex inflection point of a curve of the curved surface and is perpendicular to the radial direction.

5. The centrifugal fan according to claim 4, wherein the second guide surface (1123) comprises a second arc-shaped surface (1123a) and a second plane (1123b) that are connected, the second arc-shaped surface (1123a) is connected to the first guide surface (1122), and the second plane (1123b) is connected to the air outlet (114).

6. The centrifugal fan according to claim 5, wherein the second arc-shaped surface (1123a) and the first guide surface (1122) are connected to together form an arched surface curving toward the impeller (12).

7. The centrifugal fan according to any one of claims 4 to 6, wherein the convex surface (1121) further comprises a first plane (1121b) connected to the other end of the first arc-shaped surface (1121a), and the first plane (1121b) is connected to the air outlet (114); and from one end at which the first plane (1121b) is connected to the first arc-shaped surface (1121a) to one end at which the first plane (1121b) is connected to the air outlet (114), the first plane (1121b) is inclined outward from the cavity (111).

8. The centrifugal fan according to any one of claims 1 to 7, wherein the housing (11) comprises a side wall (11b), and a bottom wall (11a) and a top wall (11c) that are provided opposite to each other; and the side wall (11b) is located between the bottom wall (11a) and the side wall (11b), the side wall (11b), the bottom wall (11a), and the top wall (11c) together enclose the cavity (111), at least one of the bottom wall (11a) and the top wall (11 c) is provided with the air inlet (113), the side wall (11b) is provided with the air outlet (114), and an inner surface of the side wall (11b) forms the inner side surface (112) of the cavity (111).

9. The centrifugal fan according to any one of claims 1 to 8, wherein the impeller (12) comprises a hub (122) and a plurality of fan blades (123), one end of the plurality of fan blades (123) is fastened to the hub (122), and an end surface of the other end of the plurality of fan blades (123) is flush with the circumferential side surface (121) of the impeller (12).

10. An air cooling system, configured to dissipate heat for a heat generation device, and comprising a heat dissipation apparatus (20), a heat transfer apparatus (30), and the centrifugal fan (10) according to any one of claims 1 to 9, wherein the heat dissipation apparatus (20) is located at an outlet of the centrifugal fan (10), the heat dissipation apparatus (20) is connected to the heat transfer apparatus (30), and the heat transfer apparatus (30) is configured to be connected to the heat generation device.

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