Cooling fan and electronic device

Abstract

A cooling fan (10) includes a plurality of main blades (21) disposed around an axis (C1), and a plurality of guide vanes (22) disposed around the axis (C1) and each disposed between two adjacent main blades in a circumferential direction around the axis (C1) and sized smaller than the main blades (21). This configuration can improve the cooling performance of the cooling fan.

Description

Technical Field

[0001] This disclosure relates to a cooling fan and an electronic device. Background Technology

[0002] Cooling fans, used to cool heat-generating components such as central processing units (CPUs) and graphics processing units (GPUs) mounted on circuit boards, are installed inside electronic devices such as gaming devices, personal computers, and server computers. In the electronic device disclosed in WO2021 / 193882, the cooling fan is arranged with its rotation center line perpendicular to the circuit board. The cooling fan draws in external air from its top and bottom sides and expels the air radially outwards. The CPU and other components mounted on the circuit board are cooled by this air. Summary of the Invention

[0003] Technical issues One object of this disclosure is to improve the cooling performance of cooling fans used for heat-generating components.

[0004] Solution to the problem The present disclosure discloses a cooling fan comprising: a plurality of main blades arranged around an axis; and a plurality of guide vanes arranged around the axis and each of the guide vanes being disposed between two adjacent main blades in a circumferential direction around the axis and having a size smaller than that of the main blades.

[0005] An electronic device disclosed herein includes a circuit board and the cooling fan.

[0006] The aforementioned cooling fan and electronic components enable the guide vanes to adjust the airflow directed radially outward from the main blades. This improves the cooling performance of the cooling fan for heat-generating components. Although increasing the number of blades may reduce the amount of air delivered, the guide vanes are smaller than the main blades, thus mitigating this drawback. Attached Figure Description

[0007] [ Figure 1 A plan view of an example of the cooling fan proposed in this disclosure is shown.

[0008] [ Figure 2 Along Figure 1 The figure shows a cross-sectional view taken along line II-II. This diagram illustrates the positional relationship between the cooling fan and the circuit board.

[0009] [ Figure 3 ] Figure 1 A perspective view of the impeller included in the cooling fan shown.

[0010] [ Figure 4A The impeller is shown in a bottom view.

[0011] [ Figure 4B This view shows the positional relationship between the main blades and the guide vanes.

[0012] [ Figure 5 This view shows the positional relationship between the main blade, guide vane, outer ring, and inner ring in a cross-section along the axis.

[0013] [ Figure 6 The illustration shows an example of an electronic device equipped with a cooling fan.

[0014] [ Figure 7 ] Figure 6 Front view of the electronic device shown. Detailed Implementation

[0015] The cooling fan and electronic device disclosed herein will now be described. In this disclosure, the cooling fan 10 (see [reference]) will be used as an example. Figure 1 ) and electronic devices 90 (see Figure 6 (This is described as an example.)

[0016] In the following text, Figure 3 The Z1 and Z2 directions shown in other figures are referred to as upward and downward, respectively. In the diagram showing electronic device 90... Figure 6 In this context, the X1 and X2 directions are referred to as right and left, respectively, and the Y1 and Y2 directions are referred to as forward and backward, respectively. Figure 2 and Figure 3 In the figures, C1 is the axis of the cooling fan 10 (the axis of the impeller 20). These directions are defined to describe the shape and relative positional relationships of the components (parts, components, and parts) of the cooling fan 10 and the electronic device 90. Therefore, the directions shown in the figures do not limit the orientation of the cooling fan 10 and the electronic device 90 during use.

[0017] Cooling Fan Overview like Figure 2 As shown, the cooling fan 10 includes an impeller 20. The impeller 20 is rotatable about an axis C1 extending in a vertical direction. The impeller 20 includes a plurality of main blades 21 arranged along the direction of rotation of the impeller 20. The impeller 20 also includes a plurality of guide vanes 22 arranged along the direction of rotation. Each guide vane 22 is formed between two adjacent main blades 21. The two types of blades 21 and 22 will be described in detail below.

[0018] like Figure 2As shown, the cooling fan 10 includes an electric motor 60 at its central portion. The electric motor 60 includes a stator 62 and a rotor 61 surrounding the stator 62. The cooling fan 10 includes a motor housing 30 that houses the electric motor 60. The motor housing 30 includes a tubular portion 30a and a bottom portion 30b located at the lower end of the tubular portion 30a. The rotor 61 of the electric motor 60 is fixed to the tubular portion 30a. An impeller 20 is fixed to the motor housing 30 and rotates by the drive of the electric motor 60. The impeller 20 and the motor housing 30 can be integrally molded from resin.

[0019] like Figure 1 As shown, the cooling fan 10 includes a substrate 40. The substrate 40 includes an outer peripheral base 41 having an annular shape and a central base 42 formed inside the outer peripheral base 41 and intersecting the axis C1 of the cooling fan 10. The outer peripheral base 41 includes a plurality of attachment portions 41a protruding outward in a radial direction.

[0020] The substrate 40 is disposed, for example, on one side of the impeller 20 in the axial direction (upward in the example shown). Figure 2 As shown, the cooling fan 10 includes a support portion 50 for supporting an electric motor 60. The support portion 50 includes a motor support portion 52 located inside the motor housing 30 and supporting the stator 62. The support portion 50 includes a fixing portion 51 at its upper end that is fixed to a central base 42. The fixing portion 51 and the motor support portion 52 are made of resin.

[0021] When mounted on electronic device 90, cooling fan 10 can be arranged with substrate 40 above impeller 20, or conversely, with substrate 40 below impeller 20.

[0022] Electronic device 90 includes circuit board 80 (see Figure 6 ).like Figure 2 As shown, when mounted on electronic device 90, cooling fan 10 is arranged along the edge of circuit board 80. Circuit board 80 is positioned axially (Z1-Z2 direction in the example shown) between the upper end 21e and lower end 21f of main blade 21. When impeller 20 rotates, a portion of the airflow (in...) Figure 2 (Indicated by reference numeral F24 in the attached drawing) flows along the upper surface 80a of the circuit board 80, and another portion of the airflow (in) Figure 2 The airflow (represented by reference numeral F12) flows along the lower surface 80b of the circuit board 80. Therefore, both the component located on the upper side of the circuit board 80 (the cooling target) and the component located on the lower side of the circuit board 80 (the cooling target) can be cooled by a single cooling fan 10.

[0023] In the electronic device 90, components that generate more heat than those on the upper side of the circuit board 80 are mounted on the lower surface 80b of the circuit board 80. Therefore, as described in detail later, the impeller 20 and the circuit board 80 are arranged and configured to supply more air to the lower surface 80b of the circuit board 80 than to the upper surface 80a. Components that generate a large amount of heat, such as integrated circuits like CPUs, GPUs, and memory, or system-on-a-chip (SoCs) with their functions, can be disposed on the lower surface 80b of the circuit board 80.

[0024] main blade like Figure 3 As shown, the main blade 21 is plate-shaped and formed along the axial direction (Z1-Z2 direction), extending outward along the radial direction of the impeller 20. The inner end portion 21a of the main blade 21 (the end portion closer to the axis C1 in the radial direction) can be connected to the outer edge 22b of the inner guide ring 24 with an annular shape, which will be described later. Alternatively, the inner end portion 21a of the main blade 21 can be fixed to the tubular portion 30a of the motor housing 30.

[0025] like Figure 2 As shown, when the impeller 20 rotates, air is drawn into the impeller 20 from its upper and lower sides and is discharged to the outside along the radial direction of the impeller 20. That is, the cooling fan 10 is a centrifugal fan. Figure 2 In the figure, the airflow introduced from the upper side is indicated by reference numeral F21, and the airflow introduced from the lower side is indicated by reference numeral F11. As described above, the cooling fan 10 includes a substrate 40. When the impeller 20 rotates, air is introduced into the impeller 20 through the space between the central base 42 and the outer peripheral base 41 of the substrate 40.

[0026] Guide vanes like Figure 4A As shown, each guide vane 22 is formed between two adjacent main blades 21 in the rotational direction of the impeller 20. Each guide vane 22 has a plate-like shape formed along the axial direction. The size of each guide vane 22 is smaller than the size of the main blade 21.

[0027] This structure allows the guide vane 22 to adjust the airflow F24 and F12 that passes through the space between two adjacent main vanes 21 and is directed radially outward (see...). Figure 2 As a result, the cooling performance of the cooling fan 10 on the heat-generating components can be improved. When there are too many blades, the amount of air delivered may be reduced, but in the cooling fan 10, the size of the guide vanes 22 is smaller than the size of the main blades 21, so this disadvantage can be suppressed.

[0028] Dimensions of guide vanes like Figure 4BAs shown, the guide vane 22 includes an inner end portion (inner edge) 22a located closer to the center of the impeller 20 and an outer end portion (outer edge) 22b located radially outward. The main blade 21 also includes an inner end portion 21a located closer to the center of the impeller 20 and an outer end portion (outer edge) 21b located radially outward. In the direction along the main blade 21, the distance L2 from the inner end portion 22a to the outer end portion 22a of the guide vane 22 is less than the distance L1 from the inner end portion 21a to the outer end portion 21b of the main blade 21 in the same direction.

[0029] like Figure 5 As shown, the dimension H2 of the guide vane 22 in the axial direction is smaller than the dimension H1 of the main vane 21 in the axial direction. More specifically, the dimension H2 of the guide vane 22 can be less than half the dimension H1 of the main vane 21.

[0030] As described above, in the cooling fan 10, the dimensions of the guide vane 22 are smaller than those of the main vane 21 in both the axial direction and the direction orthogonal to the axial direction.

[0031] Position of guide vanes like Figure 5 As shown, the main blade 21 includes inner edges 21c and 21d positioned radially closer to the axis C1. Inner edge 21c extends downwards towards the axis C1 from the upper end 21e of the outer peripheral portion of the main blade 21. Inner edge 21d extends upwards towards the axis C1 from the lower end 21f of the outer peripheral portion of the main blade 21, opposite to inner edge 21c. The guide vane 22 is located radially outwards from the inner edges 21c and 21d of the main blade 21. The outer end portion 22b of the guide vane 22 is positioned radially closer to the axis C1 than the outer end portion 21b of the main blade 21. Therefore, noise caused by air impact on the guide vane 22 can be effectively reduced.

[0032] like Figure 5 As shown, the inner edges 21c and 21d of the main blade 21 can be gently curved. More specifically, the connection between the inner edge 21c and the upper end 21e, and the connection between the inner edge 21d and the lower end 21f of the main blade 21, can be curved. Therefore, the noise during the rotation of the impeller 20 (the noise caused by the inner edges 21c and 21d impacting the air) can be reduced.

[0033] like Figure 5As shown, the guide vane 22 is located between the outer peripheral portions of two adjacent main blades 21. In other words, the position of the guide vane 22 is offset radially outward from the center M1 of the main blade 21 along the direction of the main blade 21. Here, the center M1 of the main blade 21 is an arc that passes through the middle position between the inner end portion 21a and the outer end portion 21b along the direction of the main blade 21. The entire guide vane 22 can be located radially outside the center M1 of the main blade 21. The impeller 20 delivers air radially outward through the outer peripheral portions of the main blades 21. The guide vane 22 is located between the outer peripheral portions of two adjacent main blades 21, thus guiding the air toward the outer peripheral portions of the main blades 21.

[0034] Inclination of guide vanes like Figure 4B As shown, the main blade 21 can extend, for example, in a direction inclined in both the radial and rotational directions relative to the impeller 20. The main blade 21 can be bent along a portion of a spiral curve. This shape of the main blade 21 enables the cooling fan 10 to improve the efficiency of air intake and exhaust.

[0035] exist Figure 4B The diagram shows two main blades 21_1 and 21_2 that are adjacent to each other in the direction of rotation. Main blade 21_2 is the blade located on the opposite side of the rotation direction R1 of the impeller 20 relative to main blade 21_1. Main blade 21_1 is the blade located upstream in the rotation direction of the impeller 20, and main blade 21_2 is the blade located downstream in the rotation direction of the impeller 20.

[0036] like Figure 4B As shown, the guide vane 22 can be tilted relative to the main blades 21_1 and 21_2. More specifically, the guide vane 22 can be tilted such that the distance G2 between the guide vane 22 and the main blade 21_2 gradually decreases radially outward. Here, the distance G2 is the distance between the main blade 21_2 and the guide vane 22 in a direction orthogonal to the surface of the main blade 21_2.

[0037] like Figure 4B As shown, when the impeller 20 rotates, the main blades 21 generate an airflow F12a that diffuses radially outward. The airflow F12a is guided towards the main blades 21_2 by the guide vanes 22 (see airflow F12b). Then, the airflow F12b is delivered to the outside of the impeller 20 by the main blades 21_2 (see airflow F12c). This action of the guide vanes 22 can improve the cooling performance of the cooling fan 10. For example, it can increase the airflow velocity.

[0038] like Figure 4BAs shown, the inner end portion 22a of the guide vane 22 is positioned closer to the main blade 21_1 than the midpoint Ma between the two main blades 21_1 and 21_2. This arrangement of the guide vane 22 allows it to increase the amount of air directed toward the main blade 21_2. Here, the midpoint Ma is the position on a straight line extending through the inner end portion 22a and along a direction orthogonal to the surface of the main blade 21_2.

[0039] like Figure 4B As shown, the distance G1 between the guide vane 22 and the main vane 21_1 gradually increases outward in the radial direction, opposite to the distance G2. Here, distance G1 is the distance between the main vane 21_1 and the guide vane 22 in a direction orthogonal to the surface of the main vane 21_1.

[0040] like Figure 4B As shown, the outer end portion 22b of the guide vane 22 can be positioned closer to the main blade 21_2 than the intermediate position Mb between the two main blades 21_1 and 21_2. Here, the intermediate position Mb is the position on a straight line extending through the outer end portion 22b and along a direction orthogonal to the surface of the main blade 21_2. Figure 4B In a different example, the outer end portion 22b of the guide vane 22 can be positioned closer to the main blade 21_1 than the midpoint Mb between the two main blades 21_1 and 21_2.

[0041] Relationship between guide vanes and guide rings Impeller 20 may include an outer guide ring 23 (see Figure 3 ).like Figure 5 As shown, the outer guide ring 23 is located between the upper end 21e and the lower end 21f of the main blade 21 in the axial direction (Z1-Z2 direction). That is, the position of the outer guide ring 23 separates downwards from the upper end 21e and upwards from the lower end 21f. The outer guide ring 23 has an annular shape around the entire circumference of the motor housing 30 and connects all the main blades 21. The outer guide ring 23 is formed to match the position (axial position) of the circuit board 80. The outer guide ring 23 can increase the airflow velocity delivered to the circuit board 80.

[0042] The aforementioned guide vanes 22 can be formed on the outer guide ring 23. This increases the degree of freedom in the position of the guide vanes 22. That is, the outer guide ring 23 has an annular shape connecting multiple main blades 21, so when designing the impeller 20, the position and inclination of the guide vanes 22 between two adjacent main blades 21 can be easily adjusted. For example, the distance G2 between the inner end portion 22a of the guide vane 22 and the main blade 21_2 can be easily adjusted.

[0043] As described later, the velocity of the airflow delivered from the impeller 20 varies with height (position in the axial direction) and increases with the height of the outer guide ring 23 and the inner guide ring 24, which will be described later. The outer guide ring 23 is formed according to the position of the circuit board 80. Guide vanes 22 are formed on the outer guide ring 23, thereby increasing the velocity of the airflow delivered to the circuit board 80.

[0044] like Figure 5 As shown, the guide vane 22 may include an upper portion 22g formed on the upper side of the outer guide ring 23 and a lower portion 22h formed on the lower side of the outer guide ring 23. Compared to the case where the entire guide vane 22 is formed on the lower side of the outer guide ring 23, this arrangement of the guide vane 22 can, for example, reduce the distance from the outer guide ring 23 to the end portions (upper and lower ends) of the guide vane 22. Therefore, when the impeller 20 rotates, the deflection of the guide vane 22 can be suppressed. This arrangement of the guide vane 22 can improve the airflow F24 formed on the upper side of the circuit board 80 (see...). Figure 2 The speed of the airflow F12 formed on the underside of the circuit board 80 (see...) Figure 2 The speed of both. The guide vane 22 is formed on the outer guide ring 23 located between the upper end 21e and the lower end 21f of the main blade 21, so the position of the guide vane 22 in the axial direction can be easily adjusted.

[0045] exist Figure 5 In the example shown, the vertical width Wg of the upper portion 22g of the guide vane 22 is greater than the vertical width Wh of the lower portion 22h of the guide vane 22. Therefore, the velocity of the airflow F24 formed by the guide vane 22 along the upper surface 80a of the circuit board 80 can be increased.

[0046] Inner guide ring and outer guide ring In addition to the outer guide ring 23, the impeller 20 may also include an inner guide ring 24 (see Figure 3 ).like Figure 5 As shown, the inner guide ring 24 is positioned closer to the center (axis C1) in the radial direction than the outer guide ring 23. The inner edge of the inner guide ring 24 (the end portion closer to axis C1) can be connected to the outer peripheral surface of the motor housing 30. Similar to the outer guide ring 23, the inner guide ring 24 is located in the axial direction (Z1-Z2 direction) between the upper end 21e and the lower end 21f of the main blade 21. That is, the position of the inner guide ring 24 is separated downward from the upper end 21e and separated upward from the lower end 21f. The inner guide ring 24 has an annular shape around the entire circumference of the motor housing 30 and connects all the main blades 21.

[0047] The inner guide ring 24 and the outer guide ring 23 guide the air flowing into the impeller 20 radially outward. For example, as Figure 2As shown, airflows F22 and F24 are formed, which are guided by the upper surface of the outer guide ring 23 and sent outward in the radial direction; airflow F23 is formed between the outer guide ring 23 and the inner guide ring 24; and airflows F11 and F12 are guided by the lower surface of the outer guide ring 23 and the lower surface of the inner guide ring 24 and sent outward in the radial direction.

[0048] like Figure 2 As shown, the circuit board 80 can, for example, be positioned above a horizontal plane H4 at the midpoint between the upper end 21e and the lower end 21f of the main blade 21. The inner guide ring 24 can be located below the circuit board 80. The outer guide ring 23 can be located above the inner guide ring 24. Therefore, air flowing into the impeller 20 from the lower side and impacting the inner guide ring 24, as well as air flowing into the impeller 20 from the upper side and impacting the inner guide ring 24 (airflow F23 passing through the space between the two rings 24 and 23) are directed towards the lower side of the circuit board 80.

[0049] As described above, the velocity of the airflow delivered from the impeller 20 varies with height (position in the axial direction) and increases with the height of rings 24 and 23. The inner guide ring 24 is located below the circuit board 80, thus helping to improve the airflow and velocity along the lower surface 80b of the circuit board 80. The outer edge 23c of the outer guide ring 23 (see...) Figure 5 The outer guide ring 23 is located slightly below the circuit board 80. This arrangement of the outer guide ring 23, together with the inner guide ring 24, helps to improve the airflow velocity along the lower surface 80b of the circuit board 80. The outer guide ring 23 is located above the inner guide ring 24, and the inner edge 23b of the outer guide ring 23 (see...) Figure 5 It is located at approximately the same height as the circuit board 80. This arrangement of the outer guide ring 23 helps to improve the airflow and velocity along the upper surface 80a of the circuit board 80.

[0050] like Figure 4A As shown, the impeller 20 may include an outer ring 25 that connects to the outer end portion 21b of the main blade 21. The outer ring 25 may, for example, connect to the lower end of the outer end portion 21b of the main blade 21.

[0051] The positional relationships between ring 24 and circuit board 80, and between ring 23 and circuit board 80, are not limited to... Figure 2 Examples shown in other diagrams.

[0052] Electronic devices The electronic device 90 equipped with a cooling fan 10 will be described (see below). Figure 6The electronic device 90 is, for example, an entertainment device used as a gaming device or an audiovisual device. The electronic device 90 outputs motion image data generated by the execution of a game program, video / audio data obtained via a network, and video / audio data obtained from a recording medium such as an optical disc to a display device such as a television. The electronic device may be a personal computer or a server computer.

[0053] like Figure 6 As shown, the electronic device 90 includes a device body 91. The device body 91 includes a housing 91a. The housing 91a houses the aforementioned cooling fan 10. The cooling fan 10 is configured such that its axis C1, passing through the center of rotation of the cooling fan 10, points in the vertical direction of the electronic device 90. The housing 91a houses a circuit board on which various electronic components, such as a CPU and a GPU, are mounted. The housing 91a includes a heat sink (such as a heatsink or heat pipe). The heat sink is connected to an electronic component, such as the CPU. The cooling fan 10 introduces external air into the housing 91a to create an airflow through the heat sink.

[0054] Electronic device 90 includes an upper outer panel 92 covering the upper surface of housing 91a. Electronic device 90 includes a lower outer panel 93 covering the lower surface of housing 91a. Figure 6 As shown, the external components of the electronic device 90 (i.e., the upper external panel 92, the lower external panel 93, and the housing 91a) include air inlets Sa, Sb, Sc, and Sd for introducing external air into the electronic device 90.

[0055] like Figure 7 As shown, when the cooling fan 10 is driven, air is introduced from air inlets Sa and Sb in the upper portion. Air flows between the upper surface of the housing 91a and the upper outer panel 92, and is introduced into the cooling fan 10 from the upper side. When the cooling fan 10 is driven, air is introduced from air inlets Sc and Sd in the lower portion. Air flows between the lower surface of the housing 91a and the lower outer panel 93, and is introduced into the cooling fan 10 from the lower side.

[0056] like Figure 7 As shown, the cooling fan 10 is located at the edge of the circuit board 80. The air introduced into the cooling fan 10 is sent out to the outside in the radial direction by the rotation of the impeller 20, forming an airflow on the upper and lower sides of the circuit board 80.

[0057] Overview (1) As described above, the cooling fan disclosed herein includes: a plurality of main blades arranged around an axis; and a plurality of guide vanes arranged around the axis and each of the guide vanes being disposed between two adjacent main blades in the circumferential direction around the axis and having a size smaller than that of the main blades.

[0058] This structure allows the guide vanes to adjust the airflow directed radially outward from the main blades. As a result, the cooling performance of the cooling fan for heat-generating components can be improved. Although increasing the number of blades may reduce the amount of air delivered, the size of the guide vanes is smaller than that of the main blades, thus mitigating this drawback.

[0059] (2) The cooling fan according to (1), wherein the size of the guide vane in the direction along the axis is smaller than the size of the main vane in the direction along the axis.

[0060] (3) The cooling fan according to (1) or (2), wherein each main blade includes an inner end portion located closer to the axis in the radial direction and an outer end portion located on the outer side in the radial direction. Each guide vane includes an inner end portion located closer to the axis in the radial direction and an outer end portion located on the outer side in the radial direction. The size of the guide vane, represented by the distance between the inner and outer end portions of the guide vane in the direction along the main blade, is smaller than the size of the main blade, represented by the distance between the inner and outer end portions of the main blade in the direction along the main blade.

[0061] (4) The cooling fan according to any one of (1) to (3), wherein each guide vane is inclined relative to the two adjacent main blades.

[0062] (5) The cooling fan according to any one of (1) to (4) further includes an electric motor configured to rotate the plurality of main blades and the plurality of guide vanes in a first rotation direction, the first rotation direction being one of a clockwise direction and a counterclockwise direction. The plurality of main blades includes a first main blade and a second main blade positioned relative to the first main blade in a second rotation direction, the second rotation direction being the other of a clockwise direction and a counterclockwise direction. The guide vanes located between the first main blade and the second main blade are configured such that the distance between the second main blade and the guide vanes gradually decreases radially outward. When the impeller rotates, an airflow is generated that diffuses radially outward from the main blades. The airflow is guided by the guide vanes toward the second main blade. The airflow is then delivered by the second main blade to the outside of the impeller. This action of the guide vanes 22 can improve the cooling performance of the cooling fan 10. For example, it can increase the airflow velocity.

[0063] (6) The cooling fan according to any one of (1) to (5) further includes a guide ring extending in a circumferential direction about the axis and connected to the plurality of main blades. The guide blades are formed on the guide ring. When designing the impeller, the position and inclination of the guide blades between two adjacent main blades can be easily adjusted.

[0064] (7) The cooling fan according to (6), wherein each main blade includes a first end portion in a direction along the axis and a second end portion on a side opposite to the first end portion. The guide ring is located between the first end portion and the second end portion in a direction along the axis. This structure can suppress the deflection of the guide blades when the impeller 20 rotates.

[0065] (8) The cooling fan according to any one of (1) to (7), wherein the position of the guide vane in the radial direction is offset outward relative to the center in the direction along the main blade. This configuration allows the guide vane to direct air toward the outer peripheral portion of the main blade, which in turn directs the air outward in the radial direction. As a result, the airflow can be adjusted more effectively by the guide vane.

[0066] (9) A cooling fan according to any one of (1) to (8), wherein each of the main blades includes an outer end portion located radially outward. The guide vanes are positioned radially closer to the axis than the outer end portions of the main blades. This configuration can effectively reduce noise caused by air impacting the guide vanes.

[0067] (10) An electronic device proposed in this disclosure includes: a circuit board on which a heat-generating component is mounted; and a cooling fan, which is a cooling fan according to any one of (1) to (9) and configured to cool the heat-generating component.

[0068] Variations The cooling fan disclosed herein is not limited to the cooling fan 10 described above.

[0069] For example, the cooling fan proposed in this disclosure does not need to include an inner guide ring 24.

[0070] and Figure 5 In a different example, the entire guide vane 22 can be located below the outer guide ring 23. This allows for a lowering of the position of the guide vane 22. Conversely, the entire guide vane 22 can be located above the outer guide ring 23. This allows for an raising of the position of the guide vane 22.

[0071] The cooling fan proposed in this disclosure does not need to include an outer guide ring 23. In this case, the guide vanes 22 can be attached, for example, to the outer peripheral surface of the motor housing 30.

[0072] In yet another example, the distance G2 between the guide vane 22 and the main vane 21_2 can be constant in the radial direction.

Claims

1. A cooling fan comprising: Multiple main blades, which are arranged around an axis; as well as Multiple guide vanes are arranged around the axis and each is positioned between two adjacent main vanes in the circumferential direction around the axis and is smaller in size than the main vanes.

2. The cooling fan of claim 1, wherein the dimension of the guide vane in the direction along the axis is smaller than the dimension of the main vane in the direction along the axis.

3. The cooling fan according to claim 1, wherein Each main blade includes an inner end portion positioned closer to the axis in the radial direction and an outer end portion located on the outer side in the radial direction. Each guide vane includes an inner end portion positioned closer to the axis in the radial direction and an outer end portion located on the outer side in the radial direction, and The size of the guide vane, represented by the distance between the inner end portion and the outer end portion of each guide vane along the direction of the main blade, is smaller than the size of the main blade, represented by the distance between the inner end portion and the outer end portion of each main blade along the direction of the main blade.

4. The cooling fan of claim 1, wherein each guide vane is inclined relative to the two adjacent main vanes.

5. The cooling fan according to claim 1, further comprising: An electric motor configured to rotate the plurality of main blades and the plurality of guide vanes along a first rotation direction, wherein the first rotation direction is one of a clockwise direction and a counterclockwise direction. The plurality of main blades includes a first main blade and a second main blade positioned relative to the first main blade along a second rotation direction, wherein the second rotation direction is either the clockwise direction or the counterclockwise direction. The guide vane located between the first main blade and the second main blade is configured such that the distance between the second main blade and the guide vane gradually decreases radially outward.

6. The cooling fan according to claim 1, further comprising: A guide ring extends in a circumferential direction around the axis and connects to the plurality of main blades, wherein The guide vanes are formed on the guide ring.

7. The cooling fan according to claim 1, wherein Each main blade includes a first end portion along the axis and a second end portion on the side opposite to the first end portion, and The flow guide ring is located between the first end portion and the second end portion in the direction along the axis.

8. The cooling fan of claim 1, wherein the position of the guide vane in the radial direction is offset outward relative to the center in the direction along the main blade in the radial direction.

9. The cooling fan according to claim 1, wherein Each of the main blades includes an outer end portion located radially outward, and The guide vane is positioned closer to the axis in the radial direction than the outer end portion of the main vane.

10. An electronic device comprising: A circuit board, on which the heating element is mounted; as well as A cooling fan, which is the cooling fan according to claim 1 and is configured to cool the heat-generating component.

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