Counter-rotating fan and heat dissipation device

Abstract

A counter-rotating fan comprises a fan frame and a fan cover, the air inlet fan is arranged in the fan frame, the air inlet fan comprises an air inlet body and a plurality of air inlet blades, and the air inlet blades are arranged on the peripheral side of the air inlet body at intervals; the air outlet fan is arranged in the fan frame and opposite to the air inlet fan, the air outlet fan comprises an air outlet body and a plurality of air outlet blades, the air outlet blades are arranged on the peripheral side of the air outlet body at intervals, the rotating direction of the air outlet blades is opposite to that of the air inlet blades, and the ends, away from the air outlet body, of the air outlet blades are bent towards the air inlet blades. According to the counter-rotating fan, the radial movement of fluid near the air outlet blades is effectively inhibited, so that the working efficiency of the counter-rotating fan is improved; the phenomenon that the air inlet blades and the air outlet blades are overlapped periodically in the rotating process of the contra-rotating fan can be reduced, the aerodynamic performance of the air outlet blades is guaranteed, and the rotating noise of the air outlet blades is reduced to a certain degree. The invention further provides a heat dissipation device which comprises the counter-rotating fan and a heat dissipation body.

Description

Technical Field

[0001] The present invention relates to the technical field of heat dissipation, and particularly to a contra-rotating fan and a heat dissipation device. Background Art

[0002] With the rapid development of electronic technology, the operating speeds of electronic devices such as computers, servers, communication devices, and network communication devices are getting faster and faster, and the heat generated during their operation also increases accordingly. In order to dissipate this heat to ensure the normal operation of the electronic devices, the industry uses contra-rotating fans to dissipate heat from the electronic devices.

[0003] The current contra-rotating fans include an intake fan and an exhaust fan arranged oppositely, and dissipate heat from the electronic device by making the rotation directions of the intake fan and the exhaust fan opposite. However, the surface area of the fan blades of such a fan is small, which affects the working efficiency of the fan, and the noise generated during rotation is large. Summary of the Invention

[0004] In view of the above, it is necessary to provide a contra-rotating fan and a heat dissipation device to improve the working efficiency of the fan and reduce the noise generated during rotation.

[0005] In a first aspect, an embodiment of the present invention provides a contra-rotating fan, including: a fan frame; an intake fan disposed within the fan frame, the intake fan including an intake body and a plurality of intake blades, the plurality of intake blades being spaced apart and disposed on the periphery of the intake body; an exhaust fan disposed within the fan frame and disposed opposite to the intake fan, the exhaust fan including an exhaust body and a plurality of exhaust blades, the plurality of exhaust blades being spaced apart and disposed on the periphery of the exhaust body, the rotation direction of the exhaust blades being opposite to the rotation direction of the intake blades, and one end of the exhaust blade away from the exhaust body being bent towards the intake blade.

[0006] In the above-mentioned contra-rotating fan, by making one end of the exhaust blade away from the exhaust body bent towards the intake blade, the surface area of the exhaust blade is increased, the radial movement of the fluid near the exhaust blade is effectively suppressed, and more fluid is conveyed axially, thereby improving the working efficiency of the contra-rotating fan; by setting the rotation direction of the exhaust blade to be opposite to the rotation direction of the intake blade, the phenomenon of periodic overlap of the intake blade and the exhaust blade during the rotation of the contra-rotating fan can be reduced, which not only ensures the aerodynamic performance of the exhaust blade, but also reduces the rotation noise of the exhaust blade to a certain extent.

[0007] In some embodiments, the exhaust blade includes a blade body and a bent portion, two ends of the blade body are respectively connected to the exhaust body and the bent portion, and the bent portion is bent towards the intake blade relative to the blade body.

[0008] In some embodiments, the bending height of the bent portion relative to the blade body ranges from greater than 1 mm to less than 10 mm.

[0009] In some embodiments, the included angle between the bent portion and the blade body ranges from greater than 90 degrees to less than 180 degrees.

[0010] In some embodiments, the blade body and the bent portion are transitioned through an arc surface.

[0011] In some embodiments, the two opposite edges of each air outlet blade in the circumferential direction are respectively an air outlet leading edge and an air outlet trailing edge. One end of the air outlet leading edge close to the air outlet body extends toward the air inlet fan to the end of the air outlet leading edge far from the air outlet body, and one end of the air outlet trailing edge close to the air outlet body extends toward the air inlet fan to the end of the air outlet trailing edge far from the air outlet body.

[0012] In some embodiments, both the air outlet leading edge and the air outlet trailing edge are bent radially away from the air inlet blade on the air inlet body.

[0013] In some embodiments, the number of the air inlet blades is different from the number of the air outlet blades.

[0014] In some embodiments, the air outlet body and the plurality of air outlet blades are of an integral structure.

[0015] In a second aspect, an embodiment of the present invention further provides a heat dissipation device, including the contra-rotating fan and a heat dissipation body as described above. The contra-rotating fan is disposed in the heat dissipation body, and the heat dissipation body has a plurality of heat dissipation holes for discharging the fluid coming out from the contra-rotating fan.

[0016] The above heat dissipation device includes a contra-rotating fan. By bending the end of the air outlet blade of the contra-rotating fan away from the air outlet body toward the air inlet blade, the surface area of the air outlet blade is increased, the radial movement of the fluid near the air outlet blade is effectively inhibited, and more fluid is conveyed axially, thereby improving the working efficiency of the contra-rotating fan. By setting the rotation direction of the air outlet blade to be opposite to the rotation direction of the air inlet blade, the phenomenon of periodic overlap between the air inlet blade and the air outlet blade during the rotation of the contra-rotating fan can be reduced, which not only ensures the aerodynamic performance of the air outlet blade but also reduces the rotation noise of the air outlet blade to a certain extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a three-dimensional structural schematic diagram of a contra-rotating fan proposed by an embodiment of the present invention.

[0018] Figure 2 is Figure 1Schematic diagram of the three-dimensional structure of the contra-rotating fan shown from another angle.

[0019] Figure 3 is Figure 1 Schematic diagram of the three-dimensional structure of the air inlet frame of the contra-rotating fan shown.

[0020] Figure 4 is Figure 3 Partial enlarged view of the air inlet frame shown in IV.

[0021] Figure 5 is Figure 1 Schematic diagram of the three-dimensional structure of the air outlet frame of the contra-rotating fan shown.

[0022] Figure 6 is Figure 1 Exploded view of the contra-rotating fan shown.

[0023] Figure 7 is Figure 6 Schematic diagram of the three-dimensional structure of the air outlet fan shown.

[0024] Figure 8 Exploded view of the heat dissipation device proposed in an embodiment of the present invention.

[0025] Description of main component symbols

[0026] Contra-rotating fan 100

[0027] Fan frame 10

[0028] Air inlet frame 11

[0029] First opening 111

[0030] Rotating groove 112

[0031] Abutting side wall 1121

[0032] Opening 1122

[0033] Engaging groove 113

[0034] Transition groove 114

[0035] Transition surface 115

[0036] Air outlet frame 12

[0037] Second opening 121

[0038] Engaging part 122

[0039] Engaging column 123

[0040] Positioning part 124

[0041] Surface arrow 13

[0042] Bus duct 14

[0043] Inlet fan 20

[0044] Inlet air body 21

[0045] Inlet air receiving cavity 211

[0046] Inlet air blade 22

[0047] Outlet fan 30

[0048] Outlet air body 31

[0049] Outlet air receiving cavity 311

[0050] Outlet air blade 32

[0051] Blade body 321

[0052] Bending part 322

[0053] Arc surface 323

[0054] Outlet air leading edge 324

[0055] Outlet air trailing edge 325

[0056] Heat dissipation body 200

[0057] Heat dissipation holes 210

[0058] Heat dissipation device 1000 Specific embodiments

[0059] The following describes in detail the embodiments of the present invention. Examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation of the present invention.

[0060] In the description of the present invention, it should be understood that the terms indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present invention, "a plurality" means two or more unless otherwise specifically defined.

[0061] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the term "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a connection that allows mutual communication; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0062] The following disclosure provides many different embodiments or examples for implementing different structures of the present invention. To simplify the disclosure of the present invention, the components and settings of specific examples are described below. Of course, they are only examples and are not intended to limit the present invention. In addition, the present invention may repeat reference numerals and / or reference letters in different examples. This repetition is for the purpose of simplification and clarity, and it does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides examples of various specific processes and materials, but those of ordinary skill in the art may be aware of the application of other processes and / or the use of other materials.

[0063] Please also refer to Figure 1 and Figure 2 , an opposite-rotation fan 100 is proposed in an embodiment of the present invention, which includes a fan frame 10, an intake fan 20, and an exhaust fan 30.

[0064] The fan frame 10 includes an intake frame 11 and an exhaust frame 12. The intake frame 11 and the exhaust frame 12 are oppositely arranged, and the shapes of both the intake frame 11 and the exhaust frame 12 are hollow cylindrical. The inside of the intake frame 11 is used to install the intake fan 20, and the inside of the exhaust frame 12 is used to install the exhaust fan 30.

[0065] Please refer to Figure 3 and Figure 4 together. The intake frame 11 has a T-shaped structure. A first opening 111 is formed on the side of the intake frame 11 away from the exhaust frame 12, and the intake fan 20 is disposed in the first opening 111. Four rotation grooves 112 and four engagement grooves 113 are recessed at one end of the outer side of the intake frame 11 close to the exhaust frame 12; the rotation groove 112 has a supporting side wall 1121 parallel to the axis of the intake frame 11, and the other side parallel to the supporting side wall 1121 in the rotation groove 112 is an opening 1122; the engagement groove 113 is located between the rotation groove 112 and the exhaust frame 12, and the engagement groove 113 communicates with the rotation groove 112. A transition groove 114 is also recessed on the outer side of the intake frame 11, and the transition groove 114 communicates with the rotation groove 112. A transition surface 115 is provided between the transition groove 114 and the engagement groove 113, and the transition surface 115 can be an inclined surface or an arc surface.

[0066] Please refer to Figure 5 Figure 5 , the air outlet frame 12 is a T-shaped structure. A second opening 121 is formed on the side of the air outlet frame 12 away from the air inlet frame 11. The air outlet fan 30 is arranged in the second opening 121. Four engaging members 122 are arranged on the outer side surface of the air outlet frame 12, and the four engaging members 122 are respectively adapted to the four rotating grooves 112 and the four engaging grooves 113. Each engaging member 122 extends in a direction away from the second opening 121, that is, each engaging member 122 extends in the direction towards the air inlet frame 11. A engaging column 123 and a positioning portion 124 are arranged on one side of each engaging member 122 close to the axis of the air outlet frame 12. The engaging column 123 and the positioning portion 124 are arranged staggeredly. The engaging column 123 is used for engaging with the engaging groove 113, and the positioning portion 124 is used for engaging with the rotating groove 112.

[0067] Please refer to Figure 6 Figure 6 , when the air inlet frame 11 and the air outlet frame 12 are installed, first, the axes of the air inlet frame 11 and the air outlet frame 12 are made to be approximately coincident on the same straight line. The air inlet frame 11 and the air outlet frame 12 approach and fit each other, and the positioning portion 124 of the air outlet frame 12 enters the opening 1122 of the rotating groove 112 of the air inlet frame 11. Then, the positioning portion 124 rotates from the opening 1122 of the rotating groove 112 towards the abutting side wall 1121, and at the same time, the engaging column 123 rotates towards the engaging groove 113 until the engaging column 123 is stuck in the engaging groove 113. At this time, the positioning portion 124 abuts against the abutting side wall 1121 of the rotating groove 112, and the air inlet frame 11 and the air outlet frame 12 cannot rotate any further.

[0068] The engaging column 123 can be a semi-cylindrical body, and the engaging groove 113 is correspondingly recessed in a semi-cylindrical shape. Such a design can make the process of engaging or separating the engaging column 123 and the engaging groove 113 smoother, improving the user experience.

[0069] It can be understood that in other embodiments, the number of the engaging grooves 113, the engaging columns 123, the positioning portions 124, and the rotating grooves 112 is not limited to 4, as long as they cooperate with each other so that the two fan bodies do not generate relative displacement in the engaged state.

[0070] It can be understood that in other embodiments, both the outer side surface of the air inlet frame 11 and the outer side surface of the air outlet frame 12 have two surface arrows 13. The two surface arrows 13 indicate the action directions of the air inlet frame 11 and the air outlet frame 12 when assembling the fan frame 10, so as to instruct the user to assemble the fan frame 10 quickly and accurately.

[0071] Wire collecting grooves 14 are respectively arranged on one side of the first opening 111 of the air inlet frame 11 and one side of the second opening 121 of the air outlet frame 12, so as to facilitate the wire harness to penetrate and be electrically connected to the air inlet fan 20 and the air outlet fan 30 respectively.

[0072] The intake fan 20 is disposed within the intake frame 11 of the fan frame 10. The intake fan 20 includes an intake body 21 and a plurality of intake blades 22. The plurality of intake blades 22 are spaced apart and disposed on the circumferential side of the intake body 21. On the side of the intake body 21 close to the exhaust fan 30, there is an intake receiving cavity 211. An intake motor (not shown in the figure) is disposed within the intake receiving cavity 211. The intake motor is connected to the bottom of the first opening 111 and is also connected to the intake body 21. The intake motor is used to drive the intake body 21 to drive the plurality of intake blades 22 to rotate counterclockwise.

[0073] The exhaust fan 30 is disposed within the exhaust frame 12 of the fan frame 10 and is disposed opposite to the intake fan 20. The exhaust fan 30 includes an exhaust body 31 and a plurality of exhaust blades 32. The plurality of exhaust blades 32 are spaced apart and disposed on the circumferential side of the exhaust body 31. On the side of the exhaust body 31 close to the intake fan 20, there is an exhaust receiving cavity 311. An exhaust motor (not shown in the figure) is disposed within the exhaust receiving cavity 311. The exhaust motor is connected to the bottom of the second opening 121 and is also connected to the exhaust body 31. The exhaust motor is used to drive the exhaust body 31 to drive the plurality of intake blades 22 to rotate clockwise.

[0074] It can be understood that the intake body 21 and the exhaust body 31 are respectively driven to rotate by two motors, which can enable the intake body 21 and the exhaust body 31 to rotate at any speed ratio, greatly avoiding the resonance phenomenon between the intake body 21 and the exhaust body 31, and thus greatly reducing the working noise of the contra-rotating fan 100.

[0075] It can be understood that in other embodiments, the intake body 21 and the exhaust body 31 can be driven to rotate by the same motor.

[0076] It can be understood that in other embodiments, the intake fan 20 rotates in the clockwise direction and the exhaust fan 30 rotates in the counterclockwise direction.

[0077] The rotation direction of the exhaust blades 32 is opposite to that of the intake blades 22, which can reduce the occurrence of the phenomenon of periodic overlap of the intake blades 22 and the exhaust blades 32 during the rotation of the contra-rotating fan 100. This not only ensures the aerodynamic performance of the exhaust blades 32 but also reduces the rotation noise of the exhaust blades 32 to a certain extent.

[0078] Please refer to Figure 7, one end of the air outlet blade 32 away from the air outlet body 31 is bent towards the air inlet blade 22. Specifically, the air outlet blade 32 includes a blade body 321 and a bent portion 322. Two ends of the blade body 321 are respectively connected to the air outlet body 31 and the bent portion 322. The bent portion 322 is bent towards the air inlet blade 22 relative to the blade body 321. In this way, the surface area of the air outlet blade 32 is increased, the radial movement of the fluid near the air outlet blade 32 is effectively inhibited, and more fluid is conveyed axially, thereby improving the working efficiency of the contra-rotating fan 100 and reducing the rotation noise of the air outlet blade 32 to a certain extent. In this embodiment, the fluid is hot air.

[0079] In this embodiment, the bent portion 322 is the entire edge of one end of the air outlet blade 32 away from the air outlet body 31.

[0080] It can be understood that in other embodiments, the bent portion 322 is a partial edge of one end of the air outlet blade 32 away from the air outlet body 31. For example, the bent portion 322 is only the middle part of the edge.

[0081] Wherein, the value range of the bending height H of the bent portion 322 relative to the blade body 321 is greater than 1 mm and less than 10 mm. In some embodiments, the value of the bending height H of the bent portion 322 relative to the blade body 321 is 1 mm, 3 mm, 5 mm, 7 mm, 9 mm, but not limited thereto. When within this range, the radial movement of the fluid near the air outlet blade 32 is effectively inhibited, and more fluid is conveyed axially, thereby improving the working efficiency of the contra-rotating fan 100.

[0082] In this embodiment, the bending height of the bent portion 322 relative to the blade body 321 gradually increases or decreases in an arc shape. It can be understood that in other embodiments, the bending height of the bent portion 322 relative to the air outlet body 31 is consistent.

[0083] In some embodiments, the value range of the included angle α between the bent portion 322 and the blade body 321 is greater than 90 degrees and less than 180 degrees. In some embodiments, the value of the included angle α between the bent portion 322 and the blade body 321 is 100 degrees, 120 degrees, 140 degrees, 160 degrees, 170 degrees, but not limited thereto. In this way, the flow field structure can be optimized, the flow field loss can be reduced, the working efficiency of the contra-rotating fan 100 is improved, and the rotation noise of the air outlet blade 32 is reduced to a certain extent.

[0084] In some embodiments, the blade body 321 and the bent portion 322 are transitioned through an arc surface 323. In this way, the flow field loss can be reduced and the appearance effect of the air outlet blade 32 is better.

[0085] In some embodiments, two opposite edges of each air outlet blade 32 in the circumferential direction are respectively an air outlet leading edge 324 and an air outlet trailing edge 325. One end of the air outlet leading edge 324 close to the air outlet body 31 extends towards the air inlet fan 20 from the end of the air outlet leading edge 324 far from the air outlet body 31, and one end of the air outlet trailing edge 325 close to the air outlet body 31 extends towards the air inlet fan 20 from the end of the air outlet trailing edge 325 far from the air outlet body 31. In this way, the radial movement of the fluid near the air outlet blade 32 can be effectively suppressed, and more fluid is conveyed axially, thereby improving the working efficiency of the contra-rotating fan 100.

[0086] In some embodiments, both the air outlet leading edge 324 and the air outlet trailing edge 325 are bent radially away from the air inlet blade 22 on the air inlet body 21. This can effectively weaken the radial component of the fluid on the blade surfaces of the air inlet blade 22 and the air outlet blade 32, so that the fluid gathers axially as much as possible, reducing the radial losses of the air inlet blade 22 and the air outlet blade 32, improving the working efficiency of the fan, and increasing the output air pressure and air volume of the contra-rotating fan 100 to a certain extent.

[0087] In some embodiments, the number of the air inlet blades 22 is different from the number of the air outlet blades 32. For example, the number of the air inlet blades 22 is four and the number of the air outlet blades 32 is five; the number of the air inlet blades 22 is three and the number of the air outlet blades 32 is four. In this way, the wake frequency of the air inlet blades 22 and the blade multiple frequencies of the air outlet blades 32 can be avoided from overlapping, thereby avoiding the superposition of the noise spectra and the resonance of the air inlet blades 22 and the air outlet blades 32. It can be understood that in other embodiments, the number of the air inlet blades 22 and the air outlet blades 32 can also be the same.

[0088] In some embodiments, the air outlet body 31 and the plurality of air outlet blades 32 are of an integral structure. In this embodiment, the air outlet body 31 and the plurality of air outlet blades 32 are formed into an integral structure by means of die molding. It can be understood that in other embodiments, the air outlet body 31 and the plurality of air outlet blades 32 are also of a split structure and are connected together by means of bolts or welding.

[0089] In the above contra-rotating fan 100, by bending the end of the air outlet blade 32 away from the air outlet body 31 towards the air inlet blade 22, that is, the air outlet blade 32 is approximately crescent-shaped, the surface area of the air outlet blade 32 is increased, the radial movement of the fluid near the air outlet blade 32 is effectively suppressed, and more fluid is conveyed axially, thereby improving the working efficiency of the contra-rotating fan 100; by setting the rotation direction of the air outlet blade 32 to be opposite to that of the air inlet blade 22, the phenomenon of periodic overlap of the air inlet blade 22 and the air outlet blade 32 during the rotation of the contra-rotating fan 100 can be reduced, which not only ensures the aerodynamic performance of the air outlet blade 32, but also reduces the rotation noise of the air outlet blade 32 to a certain extent.

[0090] Please refer to Figure 8 , an embodiment of the present invention further provides a heat dissipation device 1000, including a contra-rotating fan 100 and a heat dissipation body 200. The contra-rotating fan 100 is disposed in the heat dissipation body 200, and the heat dissipation body 200 is provided with a plurality of heat dissipation holes 210 for discharging the fluid coming out of the contra-rotating fan 100. The heat dissipation device 1000 can be a computer, a server, a communication device, a network communication device, etc., but is not limited thereto.

[0091] The above heat dissipation device 1000 includes a contra-rotating fan 100. By bending the end of the air outlet blade 32 of the contra-rotating fan 100 away from the air outlet body 31 towards the air inlet blade 22, the surface area of the air outlet blade 32 is increased, the radial movement of the fluid near the air outlet blade 32 is effectively suppressed, and more fluid is conveyed axially, thereby improving the working efficiency of the contra-rotating fan 100; by setting the rotation direction of the air outlet blade 32 to be opposite to that of the air inlet blade 22, the phenomenon of periodic overlap of the air inlet blade 22 and the air outlet blade 32 during the rotation of the contra-rotating fan 100 can be reduced, which not only ensures the aerodynamic performance of the air outlet blade 32, but also reduces the rotation noise of the air outlet blade 32 to a certain extent.

[0092] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be regarded as limiting the claimed rights. In addition, it is obvious that the term "including" does not exclude other units or steps, and the singular does not exclude the plural.

[0093] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A contra-rotating fan, characterized in that, Comprising: A fan frame; An intake fan disposed within the fan frame, the intake fan including an intake body and a plurality of intake blades, the plurality of intake blades being spaced apart and disposed on the circumferential side of the intake body; An exhaust fan disposed within the fan frame and oppositely disposed to the intake fan, the exhaust fan including an exhaust body and a plurality of exhaust blades, the plurality of exhaust blades being spaced apart and disposed on the circumferential side of the exhaust body, the rotational direction of the exhaust blades being opposite to the rotational direction of the intake blades, and one end of the exhaust blade away from the exhaust body being bent towards the intake blade.

2. The contra-rotating fan according to claim 1, characterized in that, The exhaust blade includes a blade body and a bent portion, two ends of the blade body being respectively connected to the exhaust body and the bent portion, the bent portion being bent towards the intake blade relative to the blade body.

3. The contra-rotating fan according to claim 2, characterized in that, The bending height of the bent portion relative to the blade body ranges from greater than 1 mm to less than 10 mm.

4. The contra-rotating fan according to claim 2, characterized in that, The included angle between the bent portion and the blade body ranges from greater than 90 degrees to less than 180 degrees.

5. The contra-rotating fan according to claim 2, characterized in that, The blade body and the bent portion are transitioned through an arc surface.

6. The contra-rotating fan according to claim 1, characterized in that, For each exhaust blade, two opposite edges in the circumferential direction are respectively an exhaust leading edge and an exhaust trailing edge, one end of the exhaust leading edge close to the exhaust body extending towards the intake fan to the end of the exhaust leading edge away from the exhaust body, and one end of the exhaust trailing edge close to the exhaust body extending towards the intake fan to the end of the exhaust trailing edge away from the exhaust body.

7. The contra-rotating fan according to claim 6, characterized in that, Both the exhaust leading edge and the exhaust trailing edge are bent radially away from the intake blade with respect to the intake body.

8. The contra-rotating fan according to claim 1, characterized in that, The number of the intake blades is different from the number of the exhaust blades.

9. The contra-rotating fan according to claim 1, wherein, The exhaust body and the plurality of exhaust blades are of an integral structure.

10. A heat dissipation device, characterized in that, Comprising a contra-rotating fan as described in any one of claims 1-9 and a heat dissipation body, the contra-rotating fan being disposed within the heat dissipation body, the heat dissipation body having a plurality of heat dissipation holes for discharging the fluid coming out of the contra-rotating fan.

Images