Impeller assembly, centrifugal fan and electronic equipment

Abstract

The utility model relates to the field of cooling fans, aims to solve the problem that a centrifugal fan in the prior art is low in cooling efficiency, and provides an impeller assembly, a centrifugal fan and electronic equipment. The impeller assembly comprises a hub and a plurality of fan blades. The multiple fan blades are connected to the periphery of the hub. The fan blade comprises a first blade section and a second blade section, the first blade section is connected to the hub, and the second blade section is connected to the end, away from the hub, of the first blade section; the end, away from the second blade section, of the first blade section is an inlet end, and the end, away from the first blade section, of the second blade section is an outlet end. The mounting angle of the fan blade is monotonically increased from the inlet end to the outlet end, and the mounting angle of the fan blade is an included angle between the tangential direction of a certain point on the molded line of the fan blade along the flowing direction and the opposite direction of the circumferential speed of the point. And the change gradient of the mounting angle of the first blade section is smaller than that of the mounting angle of the second blade section. The heat dissipation device has the beneficial effect of being high in heat dissipation efficiency.

Description

Technical Field

[0001] This application relates to the field of cooling fans, and more particularly, to an impeller assembly, a centrifugal fan, and an electronic device. Background Art

[0002] Some known electronic devices (such as laptops, etc.) achieve heat dissipation through centrifugal fans.

[0003] However, the centrifugal fans in the known art have the problem of low heat dissipation efficiency. Summary of the Utility Model

[0004] This application provides an impeller assembly, a centrifugal fan, and an electronic device to solve the problem of low heat dissipation efficiency of the centrifugal fans in the known art.

[0005] In a first aspect, an embodiment of this application provides an impeller assembly for a centrifugal fan. The impeller assembly includes a hub and a plurality of fan blades. The plurality of fan blades are respectively connected to the outer periphery of the hub; the fan blade includes a first blade segment and a second blade segment, the first blade segment is connected to the hub, and the second blade segment is connected to one end of the first blade segment away from the hub; one end of the first blade segment away from the second blade segment is the inlet end, and one end of the second blade segment away from the first blade segment is the outlet end. Among them, the installation angle of the fan blade monotonically increases from the inlet end to the outlet end, where the installation angle of the fan blade refers to the angle between the tangent direction of a certain point on the blade profile along the flow direction and the reverse direction of the circumferential velocity of this point. The change gradient of the installation angle of the first blade segment is less than the change gradient of the installation angle of the second blade segment.

[0006] The impeller assembly of this embodiment can increase the air volume of the centrifugal fan under the same noise through the control of the increasing installation angle profile and the settings such as the small change gradient of the installation angle of the first blade segment and the second blade segment.

[0007] In a possible implementation manner, one side or both sides in the height direction of the first blade segment are concave relative to the second blade segment to form a cut-off area, so that the height of the first blade segment is greater than that of the first blade segment.

[0008] The fan blade of this implementation manner can reduce the noise generated when the air flow enters between adjacent fan blades and has no obvious influence on the work efficiency of the fan blade.

[0009] In a possible implementation manner, the fan blade further includes a transition blade segment, and the transition blade segment is connected between the hub and the first blade segment; the radius of the circle where the outer radial end of the transition blade segment is located is 1.05 - 1.30 times the outer peripheral radius of the hub.

[0010] In this implementation manner, the setting of the transition blade segment enables the fan blade to better adapt to the mold opening requirements of the impeller assembly.

[0011] In a possible implementation, in the radially outward direction, the installation angle of the transition blade segment decreases from large to small.

[0012] In this implementation, the installation angle of the transition blade decreases from large to small, enabling the fan blade to better adapt to the mold opening requirements of the impeller assembly.

[0013] In a possible implementation, the height of the transition blade segment is equal to the height of the first blade segment.

[0014] The fan blade of this implementation can reduce the noise generated when the air flow enters between adjacent fan blades, and has no obvious impact on the work efficiency of the fan blade.

[0015] In a possible implementation, the value of the outlet angle of the fan blade is 110° to 145°; wherein, the outlet angle refers to the installation angle at the end point of the second blade segment of the fan blade far from the hub. The inlet angle of the fan blade is 30° to 60°; wherein, the inlet angle refers to the installation angle at the end point of the first blade segment of the fan blade far from the second blade segment.

[0016] In this implementation, the fan blade has a relatively large outlet angle, and the difference between the inlet angle and the outlet angle of the fan blade is relatively large, which can increase the air volume output of the centrifugal fan under the same noise.

[0017] In a possible implementation, the radial extension distance of the first blade segment is greater than or equal to 2 / 3 of the radial extension distance of the fan blade, and the radial extension distance of the second blade segment is less than 1 / 3 of the radial extension distance of the fan blade. In the radially outward direction, the increase value of the installation angle of the first blade segment is 30° to 45°. In the radially outward direction, the increase value of the installation angle of the second blade segment is 50° to 70°.

[0018] In this implementation, the installation angle change gradient is small for the first blade segment and large for the second blade segment, which is beneficial to increasing the air volume output of the centrifugal fan under the same noise.

[0019] In a possible implementation, the impeller assembly further includes a fixing ring, and the radially outer ends of multiple fan blades are respectively connected to the fixing ring.

[0020] In this implementation, the fixing ring can improve the stiffness of the impeller assembly, which is beneficial to reducing the bending deformation of the fan blade caused by the reaction force of the air flow during operation.

[0021] In a second aspect, an embodiment of the present application provides a centrifugal fan, which includes a housing, a driving member, and the aforementioned impeller assembly. The housing has a chamber. The impeller assembly is disposed in the chamber. The driving member is installed on the housing and is drivingly connected to the hub of the impeller assembly for driving the impeller assembly to rotate.

[0022] The centrifugal fan of this embodiment adopts the aforementioned impeller assembly and has a relatively large air volume output under the same noise.

[0023] In a possible implementation, the housing includes a lower housing and a cover plate. The lower housing includes a bottom plate and a surrounding plate, and the surrounding plate is connected to one side of the bottom plate; the cover plate is connected to the side of the surrounding plate away from the bottom plate and is spaced opposite to the bottom plate. The impeller assembly is disposed between the bottom plate and the cover plate. The cover plate is provided with an air inlet, the air inlet is in a circular hole shape, and the outer edge of the air inlet is located at the junction of the first blade segment and the second blade segment.

[0024] In this implementation, the outer edge of the air inlet is located at the junction of the first blade segment and the second blade segment, so that the centrifugal fan has a larger air inlet and does not affect the second blade segment as the core work - doing segment to do work.

[0025] In a third aspect, an embodiment of the present application provides an electronic device, including a housing and the aforementioned centrifugal fan. The centrifugal fan is disposed inside the housing.

[0026] The electronic device of this embodiment uses the aforementioned centrifugal fan and has a good heat dissipation effect under the same noise.

[0027] In a possible implementation, the electronic device is a notebook computer, a tablet computer, a smart screen or an all - in - one desktop computer.

[0028] This implementation gives some electronic devices to which the aforementioned centrifugal fan can be applied.

[0029] In a possible implementation, the housing is provided with an air inlet hole and an air outlet hole; the air inlet of the centrifugal fan is communicated with the air inlet hole, and the air outlet of the centrifugal fan faces the air outlet hole. The electronic device further includes a heat source component, a heat pipe and a heat sink fin group; one end of the heat pipe is thermally connected to the heat source component, the other end is thermally connected to the heat sink fin group, and the heat sink fin group is located between the air outlet and the air outlet hole.

[0030] In this implementation, the heat dissipation capacity of the centrifugal fan can be fully utilized through the heat pipe and the heat sink fin group. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, so they should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0032] Figure 1 is a perspective view of the electronic device of the embodiment of the present application;

[0033] Figure 2 is Figure 1 a bottom view of the base part of the electronic device of

[0034] Figure 3 is Figure 2 an enlarged view of part A of

[0035] Figure 4 a schematic structural view of another electronic device according to an embodiment of the present application;

[0036] Figure 5 a perspective view of a centrifugal fan according to an embodiment of the present application;

[0037] Figure 6 is Figure 5 an exploded view of the centrifugal fan of

[0038] Figure 7 is Figure 5 a schematic structural view of an impeller assembly of the centrifugal fan of

[0039] Figure 8 a schematic view of a hub and a blade of this embodiment;

[0040] Figure 9 a perspective view of a blade according to an embodiment of the present application;

[0041] Figure 10 is Figure 9 another perspective view of the blade of

[0042] Figure 11 another perspective view of 8;

[0043] Figure 12 shows the radial partitioning of the transition blade segment, the first blade segment, and the second blade segment of the blade of this embodiment;

[0044] Figure 13 is Figure 8 a partial enlarged view of , and the installation angles at the first blade segment and the second blade segment are shown in the figure;

[0045] Figure 14 shows Figure 8 an enlarged view of part B of , and the installation angle at the transition blade segment is shown in the figure;

[0046] Figure 15 a curve graph showing the variation of the installation angle of the blade of this embodiment with the radius;

[0047] Figure 16 a perspective view of another blade according to an embodiment of the present application.

[0048] Description of main element symbols:

[0049] Electronic device 100

[0050] Base part 1

[0051] Housing 101

[0052] Keyboard assembly 102

[0053] Touchpad 103

[0054] Centrifugal fan 110

[0055] Heat source component 120

[0056] Central processing unit 120a

[0057] Heat pipe 130

[0058] Heat dissipation fin group 140

[0059] Display screen part 2

[0060] Display screen 201

[0061] Camera 202

[0062] Housing 10

[0063] Lower housing 11

[0064] Bottom plate 11a

[0065] Enclosure 11b

[0066] Cover plate 12

[0067] Drive component 20

[0068] Impeller assembly 30

[0069] Hub 31

[0070] Fan blades 32, 35

[0071] First blade segment 32a

[0072] Second blade segment 32b

[0073] Transition blade segment 32c

[0074] Fixing ring 33

[0075] Air inlet hole K1

[0076] Air exhaust hole K2

[0077] Airflow inlet K3

[0078] Airflow outlet K4

[0079] Auxiliary airflow inlet K5

[0080] Cooling airflow A1

[0081] Chamber Q1

[0082] Cutting area C1

[0083] Height direction Z

[0084] Rotation direction W

[0085] Profile line S1 Detailed implementation manners

[0086] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments.

[0087] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intermediate element at the same time. When an element is considered to be "disposed on" another element, it can be directly disposed on the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0088] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application herein are only for the purpose of describing specific implementation manners and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0089] Some implementation manners of the present application will be described in detail. Without conflict, the following implementation manners and the features in the implementation manners can be combined with each other.

[0090] Embodiment

[0091] This embodiment provides an electronic device 100, which can be a notebook computer, a tablet computer, an all-in-one desktop computer, a smart screen, etc.

[0092] Figure 1 An electronic device 100 is shown, which is specifically a notebook computer. Figure 2 For Figure 1 The bottom part 1 of the electronic device 100 is shown in a bottom view.

[0093] See Figure 1 And Figure 2, the electronic device 100 includes a base portion 1 and a display portion 2, and the display portion 2 is rotatably connected to the base portion 1. The display portion 2 can be closed on the base portion 1 or can be rotated and opened relative to the base portion 1. Figure 1 The display portion 2 of the electronic device 100 in Figure 1 is in an open state.

[0094] The display portion 2 mainly includes components such as a display screen 201 and a camera 202.

[0095] The base portion 1 includes a housing 101 and components such as a main board, a memory, a graphics card, a keyboard assembly 102, and a touchpad 103 installed in the housing 101. Among them, the keyboard assembly 102 and the touchpad 103 are exposed outside the housing 101 and are used to receive user input. Components such as the main board, the memory, and the graphics card are arranged inside the housing 101.

[0096] When the electronic device 100 is running, components such as the graphics card and the central processing unit 120a (Central Processing Unit, CPU) of the main board will generate heat. If this heat cannot be discharged from the housing 101 in time, it will cause the temperature of the electronic device 100 to rise, affecting the performance of the electronic device 100 and even causing some components of the electronic device 100 to be damaged.

[0097] This embodiment also provides a centrifugal fan 110 for dissipating heat from the heat source components 120 (such as the central processing unit 120a and the graphics card) of the electronic device 100.

[0098] Continue to refer to Figure 2 , in the electronic device 100, the housing 101 is provided with an air inlet hole K1 and an air outlet hole K2. The centrifugal fan 110 is arranged inside the housing 101 of the electronic device 100, and the air inlet K3 of the centrifugal fan 110 is communicated with the air inlet hole K1, and the air outlet K4 of the centrifugal fan 110 faces the air outlet hole K2.

[0099] The electronic device 100 further includes a heat pipe 130 and a heat sink fin group 140. One end of the heat pipe 130 is thermally connected to the heat source component 120 (such as the central processing unit 120a), and the other end is thermally connected to the heat sink fin group 140, and the heat sink fin group 140 is located between the air outlet K4 and the air outlet hole K2.

[0100] Optionally, in this embodiment, there are two centrifugal fans 110. Correspondingly, there are also two heat pipes 130 and two heat sink fin groups 140 respectively. In this way, the heat dissipation effect can be further achieved.

[0101] Combined with reference to Figure 3, when the centrifugal fan 110 operates, it can drive the outside air to enter the casing 101 through the air inlet hole K1 of the casing 101 and discharge it from the air outlet hole K2 of the casing 101, forming a cooling air flow A1. During this process, the heat generated by the operation of the heat source component 120 is transferred to the heat dissipation fin group 140 through the heat pipe 130 and then carried out of the casing 101 by the cooling air flow A1, thereby realizing the cooling of the heat source component 120 and even the overall cooling inside the casing 101.

[0102] Optionally, the centrifugal fan 110 in this embodiment can be electrically connected to the main board, and the main board can control the rotation speed of the centrifugal fan 110 according to the temperature of the heat source component 120. For example, when the temperature of the heat source component 120 is relatively high, the main board can control the centrifugal fan 110 to rotate at a higher speed to dissipate heat quickly; when the temperature of the heat source component 120 is relatively low, it can control the centrifugal fan 110 to rotate at a lower speed to reduce the operation noise of the centrifugal fan 110.

[0103] In other embodiments, the number of the centrifugal fans 110 can also be one, three or more, which is not limited herein.

[0104] In other embodiments, the heat pipe 130 and / or the heat dissipation fin group 140 can also be discarded, and the centrifugal fan 110 can directly blow air towards the heat source component 120 to achieve cooling.

[0105] Figure 4 Another electronic device 100a is shown, which is specifically a tablet computer.

[0106] See Figure 4 , inside the casing 101 of the electronic device 100a (tablet computer), there are provided a heat source component 120 (such as a central processing unit 120a), a heat pipe 130, a heat dissipation fin group 140 and a centrifugal fan 110. One end of the heat pipe 130 is thermally connected to the heat source component 120, and the other end is thermally connected to the heat dissipation fin group 140. The air outlet K4 of the centrifugal fan 110 corresponds to the heat dissipation fin group 140. After the heat generated by the heat source component 120 is transferred to the heat dissipation fin group 140 through the heat pipe 130, it can be blown out of the casing 101 from the air outlet hole K2 of the casing 101 by the cooling air flow A1 generated by the centrifugal fan 110, realizing the heat dissipation of the electronic device 100a.

[0107] The centrifugal fan 110 in this embodiment can also be applied to other types of electronic devices, which will not be elaborated herein.

[0108] Next, in conjunction with Figures 5 - 14 an exemplary introduction will be given to a centrifugal fan 110 provided in this embodiment.

[0109] See Figure 5 and Figure 6, in this embodiment, the centrifugal fan 110 includes a housing 10, a driving member 20, and an impeller assembly 30.

[0110] Among them, the impeller assembly 30 includes a hub 31 and a plurality of fan blades 32, and the plurality of fan blades 32 are respectively connected to the outer periphery of the hub 31. Optionally, the impeller assembly 30 is made of a plastic material, and the plurality of fan blades 32 and the hub 31 are integrally injection-molded.

[0111] In other embodiments, the impeller assembly 30 can also be made of other materials.

[0112] The housing 10 has a chamber Q1, and the impeller assembly 30 is disposed in the chamber Q1. The driving member 20 is installed on the housing 10 and is drivingly connected to the hub 31 of the impeller assembly 30 for driving the impeller assembly 30 to rotate to generate a cooling air flow A1 (visible in Figure 3 or Figure 4 ).

[0113] Optionally, the housing 10 includes a lower housing 11 and a cover plate 12. The lower housing 11 includes a bottom plate 11a and a surrounding plate 11b. The surrounding plate 11b is connected to one side of the bottom plate 11a. The cover plate 12 is connected to the side of the surrounding plate 11b away from the bottom plate 11a and is spaced opposite to the bottom plate 11a. The surrounding plate 11b is a circumferentially unclosed structure, so that the bottom plate 11a, the surrounding plate 11b, and the cover plate 12 enclose an air flow outlet K4 of the centrifugal fan 110. The cover plate 12 is provided with an air flow inlet K3. Optionally, the air flow inlet K3 is in the shape of a circular hole. Optionally, the lower housing 11 can also be provided with an auxiliary air flow inlet K5 for increasing the air intake.

[0114] The driving member 20 can be a motor, the stator of which is fixed to the lower housing 11 of the housing 10, and the rotor is connected to the hub 31. In this embodiment, the hub 31 can be used as the mounting shell of the rotor. During operation, the rotor of the driving member 20 can drive the impeller assembly 30 to rotate through the hub 31.

[0115] When the impeller assembly 30 is running, the driving member 20 drives the impeller assembly 30 to rotate, so that air enters the chamber Q1 inside the housing 10 from the air flow inlet K3 and is centrifugally discharged from the air flow outlet K4 of the centrifugal fan 110 by the fan blades 32 of the impeller assembly 30 for cooling the heat source member 120.

[0116] With reference to Figure 7 , in this embodiment, optionally, the impeller assembly 30 further includes a fixing ring 33. The radially outer ends of the plurality of fan blades 32 are respectively connected to the fixing ring 33. Among them, the radially outer end refers to the outer end in the radial direction of the impeller assembly 30. The fixing ring 33 can improve the stiffness of the impeller assembly 30 and is beneficial to reducing the bending deformation of the fan blades 32 caused by the reaction force of the air flow during operation.

[0117] The fan blade 32 of this centrifugal fan 110 is a forward-curved fan blade, that is, the fan blade 32 bends forward in the direction W of rotation of the impeller assembly 30.

[0118] Figure 8 The hub 31 of the impeller assembly 30 and one of the fan blades 32 are shown. Figure 9 It is a perspective view of the fan blade 32 in this embodiment.

[0119] See Figure 8 and Figure 9 In this embodiment, the fan blade 32 includes a transition blade segment 32c, a first blade segment 32a, and a second blade segment 32b. The first blade segment 32a is connected between the transition blade segment 32c and the second blade segment 32b. The first blade segment 32a is located at the radially inner end of the fan blade 32, the second blade segment 32b is located at the radially outer end of the fan blade 32, and the first blade segment 32a is transitionally connected to the outer peripheral surface of the hub 31 through the transition blade segment 32c.

[0120] In this embodiment, it is defined that one end of the first blade segment 32a away from the second blade segment 32b is the inlet end, and one end of the second blade segment 32b away from the first blade segment 32a is the outlet end. When the centrifugal fan 110 operates, the air flow enters between the adjacent fan blades 32 in the housing 10 from the air inlet K3. Then, under the guidance of the fan blade 32, the air flow flows radially from the inlet end to the outlet end and finally blows out from the air outlet K4 of the centrifugal fan 110, so as to be used for cooling.

[0121] See Figure 10 and Figure 11 In this embodiment, the height of the first blade segment 32a is less than the height of the second blade segment 32b, and the height of the transition blade segment 32c is equal to that of the first blade segment 32a. Among them, the height direction Z of the fan blade 32 is the direction parallel to the rotation axis of the hub 31.

[0122] For example, the height of the second blade segment 32b is equal everywhere, the height of the transition blade segment 32c is equal everywhere and less than that of the second blade segment 32b. The two sides of the first blade segment 32a in the height direction Z are concave relative to the second blade segment 32b to form a cut-off area C1, so that the height of the first blade segment 32a at the end connecting the transition blade segment 32c is smaller, and the height at the end connecting the second blade segment 32b is larger, so that the first blade segment 32a is substantially trapezoidal in Figure 10 or Figure 11 . For the fan blade 32 of this embodiment, by forming the cut-off area C1 at the transition blade segment 32c connecting the hub 31 and the part of the first blade segment 32a close to the transition blade segment 32c, the noise generated when the air flow enters between the fan blades 32 from the air inlet K3 can be reduced.

[0123] Of course, the cutting area C1 should not be too large. For example, after cutting, the height of the transition blade segment 32c should at least retain 70-80% of the height of the second blade segment 32b to ensure that the strength requirements at the connection between the fan blade 32 and the hub 31 are met.

[0124] Referring to Figure 12 , in this embodiment, the radial extension distance of the transition blade segment 32c is 1.05-1.30 times the outer peripheral radius of the hub 31, such as 1.2 times. Herein, the radial extension distance refers to the difference in radius between the circle where the radial inner end is located and the circle where the radial outer end is located. For example Figure 12 as shown in

[0125] Continuing to refer to Figure 12 , in this embodiment, the radial extension distance of the first blade segment 32a is greater than that of the second blade segment 32b. For example, the radial extension distance of the first blade segment 32a is greater than or equal to 2 / 3 of the radial extension distance of the fan blade 32, and the radial extension distance of the second blade segment 32b is less than 1 / 3 of the radial extension distance of the fan blade 32.

[0126] Such as Figure 12 as shown in

[0127] According to the foregoing definition, in this embodiment, the end point at the inlet is the end point P1 of the first blade segment 32a far from the second blade segment 32b, and the end point at the outlet is the end point P3 of the second blade segment 32b far from the first blade segment 32a.

[0128] Referring to Figure 13 , in this embodiment, the installation angle of the fan blade 32 monotonically increases from the inlet end to the outlet end. Herein, the installation angle of the fan blade 32 refers to the angle between the tangent direction of a certain point on the profile line S1 of the fan blade 32 along the flow direction and the opposite direction of the circumferential velocity of this point. Herein, the profile line S1 refers to the extension line of the fan blade 32, Figure 13It is represented by the side line on the right side of the fan blade 32 facing right. The tangent direction of a certain point along the flow direction refers to the direction in which the tangent at that point on the profile line S1 points to the radially outer end. The reverse direction of the circumferential velocity of a certain point refers to the reverse direction of the linear velocity when the fan blade 32 rotates, which is perpendicular to the line connecting that point and the rotation center of the hub 31 and is opposite to the rotation direction W of the hub 31.

[0129] In this embodiment, the installation angle of the fan blade 32 monotonically increases from the inlet end to the outlet end, which can ensure the work efficiency of the fan blade 32 and is beneficial to increasing the air output.

[0130] In contrast, for some known centrifugal fans, the profile line of the fan blade is composed of two arcs with the centers of the circles tangent to both sides of the profile line, and the installation angle of the fan blade shows a trend of first decreasing and then increasing, which limits the improvement of the work efficiency of the fan blade and the air output. That is, under the same noise, the centrifugal fan 110 of this embodiment can provide a larger air output, thus having a better cooling effect.

[0131] According to the above definition, the inlet angle α1 of the fan blade 32, that is, the installation angle at the end point P1, is the angle between the tangent direction L12 of the end point P1 along the flow direction and the reverse direction L11 of the circumferential velocity of the end point P1.

[0132] Similarly, the outlet angle α3 of the fan blade 32, that is, the installation angle at the end point P3, is the angle between the tangent direction L32 of the end point P3 along the flow direction and the reverse direction L31 of the circumferential velocity of the end point P1.

[0133] The installation angle α2 at the junction end point P2 of the first blade segment 32a and the second blade segment 32b is the angle between the tangent direction L22 of the end point P2 along the flow direction and the reverse direction L21 of the circumferential velocity of the end point P2.

[0134] In this embodiment, optionally, the inlet angle α1 of the fan blade 32 is from 30° to 60°, for example, 30°, and the value of the outlet angle α3 of the fan blade 32 is from 110° to 145°, for example, 130°. This embodiment uses a fan blade with a large outlet angle (such as more than 130°), which has a larger air output under the same lamp noise.

[0135] In this embodiment, the change gradient of the installation angle of the first blade segment 32a is less than the change gradient of the installation angle of the second blade segment 32b. Among them, the change gradient of the installation angle refers to the speed at which the installation angle changes with the change of the radial extension distance of the fan blade 32.

[0136] In this embodiment, by making the variation gradient of the installation angle of the first blade segment 32a smaller than that of the second blade segment 32b, the first blade segment 32a is in a relatively straight state, while the second blade segment 32b is in a more curved state. In this way, the working efficiency of the fan blade 32 can be further improved, and the air volume output of the centrifugal fan 110 is larger.

[0137] Optionally, from the radially inner end to the radially outer end of the first blade segment 32a, the increase value of the installation angle of the first blade segment 32a is 30° to 45°, for example, 42°; from the radially inner end to the radially outer end of the second blade segment 32b, the increase value of the installation angle of the second blade segment 32b is 50° to 70°, for example, 60°.

[0138] For example, in one implementation, the inlet angle α1 of the fan blade 32 is 30°, the installation angle α2 of the end point P2 is 72°, and the outlet angle α3 of the fan blade 32 is 130°. It can be calculated that the increase value of the installation angle of the first blade segment 32a is 42°, and the increase value of the installation angle of the second blade segment 32b is 58°.

[0139] Combined with the foregoing description, in this embodiment, the first blade segment 32a has a larger radial extension distance and a smaller increase value of the installation angle, while the second blade segment 32b has a smaller radial extension distance and a larger increase value of the installation angle, that is, the variation gradient of the installation angle of the first blade segment 32a is smaller than that of the second blade segment 32b.

[0140] In this embodiment, optionally, the outer edge of the air flow inlet K3 (i.e., the side line of the circular hole) is located at the junction of the first blade segment 32a and the second blade segment 32b, that is, passing through the end point P2. In this way, the air flow can enter the relatively straight first blade segment 32a through the air flow inlet K3, and then be driven by the rotating fan blade 32 to enter the second blade segment 32b centrifugally, and be forced to do work by the second blade segment 32b with a larger degree of bending, so as to be blown out of the housing 10 at a larger speed. In this way, it can be ensured that the centrifugal fan 110 has sufficient air intake and the air flow is blown out at a larger speed, ensuring the cooling effect. That is, the second blade segment 32b is the core working area of the fan blade 32, and its installation angle is large and the variation gradient of the installation angle is large, which is beneficial to increasing the air volume output of the centrifugal fan 110.

[0141] In addition, in this embodiment, since the variation gradient of the installation angle of the first blade segment 32a is smaller than that of the second blade segment 32b, a cut-off area C1 is provided in the transition blade segment 32c and the first blade segment 32a (see Figure 11 ), which can reduce the inlet noise while having a small impact on the work of the fan blade 32, ensuring the air volume output of the centrifugal fan 110.

[0142] See in conjunction with Figure 14, in this embodiment, the transition blade segment 32c is transitionally connected between the hub 31 and the first blade segment 32a. The installation angle of the transition blade segment 32c is larger at the end connected to the hub 31 and smaller at the end connected to the first blade segment 32a, and the installation angle of the transition blade segment 32c decreases from large to small in the radially outward direction. Among them, the first blade segment 32a can be arc-shaped.

[0143] According to the definition of the aforementioned installation angle, the installation angle α0 at the end point P0 of the radially inner end of the transition blade segment 32c is the angle between the tangent direction L02 of the end point P0 along the flow direction and the reverse direction L01 of the circumferential velocity of the end point P0.

[0144] In this embodiment, the installation angle α0 at the end point P0 of the radially inner end of the transition blade segment 32c is greater than the installation angle α1 at the end point P1 of the radially outer end of the transition blade segment 32c. For example, the installation angle α0 is 44°, and the installation angle α1 is 30°. The larger installation angle α0 at the end point P0 can better meet the mold opening requirements of the impeller assembly 30.

[0145] Figure 15 The curve showing the variation of the installation angle α of the fan blade 32 of the centrifugal fan 110 in an embodiment is shown.

[0146] As Figure 15 , in the fan blade 32, in the region of the transition blade segment 32c, the installation angle gradually decreases; in the region of the first blade segment 32a, the installation angle slowly increases; in the region of the first blade segment 32a, the installation angle rapidly increases.

[0147] According to practical tests, for the single centrifugal fan 110 using the fan blade 32, its noise can be controlled at about 26 - 30 dB, the input system speed is 4500 - 4900 rpm, and the input system air volume is as high as 1.02 - 1.06 CFM.

[0148] For the electronic device 100 using a double fan, its total system air volume can reach 2.08 CFM. Compared with some centrifugal fans that do not adopt the fan blade 32 design of this embodiment, at the same noise level, the air volume gain of the electronic device 100 is 0.17 CFM, and the air volume is increased by about 9%.

[0149] Figure 16 Another fan blade 35 is shown, and its difference from the Figure 9 fan blade 32 is only that Figure 16 the fan blade 35 of Figure 9 only has a cut-out area C1 on one side, while the fan blade 32 of

[0150] Based on the above description, in this embodiment, by adopting settings such as a larger outlet angle (e.g., the outlet angle is greater than 110°), installation angle increasing type line control, and a small installation angle change gradient in the first blade segment 32a and a large one in the second blade segment 32b, the air volume output of the centrifugal fan 110 can be increased under the same noise level.

[0151] The above embodiments are only used to illustrate the technical solutions of the present application rather than to limit them. Although the present application has been described in detail with reference to the above preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present application can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present application.

Claims

1. An impeller assembly for a centrifugal fan, characterized in that: The impeller assembly comprises: Wheel hub; and A plurality of blades, wherein the plurality of blades are respectively connected to the outer periphery of the hub; the blades include a first blade segment and a second blade segment, wherein the first blade segment is connected to the hub, and the second blade segment is connected to an end of the first blade segment away from the hub; an end of the first blade segment away from the second blade segment is an inlet end, and an end of the second blade segment away from the first blade segment is an outlet end; The installation angle of the fan blade increases monotonically from the inlet end to the outlet end, wherein the installation angle of the fan blade refers to the angle between the tangent direction of a certain point on the profile of the fan blade along the flow direction and the opposite direction of the circumferential velocity of the point; The change gradient of the installation angle of the first blade segment is smaller than the change gradient of the installation angle of the second blade segment.

2. The impeller assembly according to claim 1, characterized in that: One side or both sides of the first leaf segment in the height direction are concave relative to the second leaf segment to form a cut-out area, so that the height of the first leaf segment is greater than that of the second leaf segment.

3. The impeller assembly according to any one of claims 1 to 2, characterized in that: The fan blade also includes a transition blade segment, which is connected between the hub and the first blade segment; the radius of the circle where the radial outer end of the transition blade segment is located is 1.05-1.30 times the outer circumferential radius of the hub.

4. The impeller assembly according to claim 3, characterized in that: In the radially outward direction, the installation angle of the transition blade segment decreases from large to small.

5. The impeller assembly according to claim 3, characterized in that: The height of the transition blade segment is equal to the height of the first blade segment.

6. The impeller assembly according to claim 1, characterized in that: The value of the outlet angle of the fan blade is 110° to 145°; wherein the outlet angle refers to the installation angle of the end point of the second blade segment of the fan blade away from one end of the hub; The inlet angle of the fan blade is 30° to 60°; wherein the inlet angle refers to the installation angle of the first blade segment of the fan blade at the end point away from one end of the second blade segment.

7. The impeller assembly according to claim 1 or 6, characterized in that: The radial extension distance of the first blade segment is greater than or equal to 2 / 3 of the radial extension distance of the fan blade, and the radial extension distance of the second blade segment is less than 1 / 3 of the radial extension distance of the fan blade; In the radially outward direction, the increase value of the installation angle of the first blade segment is 30° to 45°; In the radially outward direction, the increase value of the installation angle of the second blade segment is 50° to 70°.

8. The impeller assembly according to claim 1, characterized in that: The impeller assembly also includes a fixing ring, and radial outer ends of the plurality of blades are respectively connected to the fixing ring.

9. A centrifugal fan, characterized in that: include: a housing having a chamber; as well as, The impeller assembly according to any one of claims 1 to 8, wherein the impeller assembly is arranged in the chamber; A driving member is installed on the housing and is transmission-connected to the hub of the impeller assembly to drive the impeller assembly to rotate.

10. The centrifugal fan according to claim 9, characterized in that: The housing comprises a lower shell and a cover plate, the lower shell comprises a bottom plate and a surrounding plate, the surrounding plate is connected to one side of the bottom plate; the cover plate is connected to a side of the surrounding plate away from the bottom plate and is spaced opposite to the bottom plate; The impeller assembly is arranged between the base plate and the cover plate; The cover plate is provided with an air flow inlet which is in the shape of a circular hole, and an outer edge of the air flow inlet is located at the junction of the first blade segment and the second blade segment.

11. An electronic device, characterized in that: include: chassis; as well as, The centrifugal fan according to any one of claims 9 to 10; the centrifugal fan is arranged in the casing.

12. The electronic device according to claim 11, characterized in that: The electronic device is a laptop computer, a tablet computer, a smart screen or an all-in-one desktop computer.

13. The electronic device according to claim 11, characterized in that: The housing is provided with an air inlet and an air outlet; the air inlet of the centrifugal fan is connected to the air inlet, and the air outlet of the centrifugal fan faces the air outlet; The electronic device also includes a heat source, a heat pipe and a heat dissipation fin group; one end of the heat pipe is thermally connected to the heat source, and the other end is thermally connected to the heat dissipation fin group, and the heat dissipation fin group is located between the air flow outlet and the exhaust hole.

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