CN201068873Y

CN201068873Y - Electronic chip heat radiating fan

Info

Publication number: CN201068873Y
Application number: CNU2007201208680U
Authority: CN
Inventors: 秦彪
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-06-15
Filing date: 2007-06-15
Publication date: 2008-06-04
Anticipated expiration: 2017-06-15

Abstract

The utility model provides a two-level axial flow mini fan used for the radiators of electronic chips. A DC brushless motor can be used for driving two fan blades (5), and a rectifier (6) is arranged between two fan blades (5). Under the condition that the thickness of the fan is not increased, the utility model adopts a compact structure to effectively improve the wind pressure of the fan and to overcomes the increasing of the wind resistance caused by the compactification of the air heat exchanging ribs in the radiator, thereby effectively reducing the size of the radiator.

Description

A kind of thermal fan for electronic chips

Affiliated technical field

The utility model relates to the heat dissipation technology of electronic device, especially on the electronic chip radiator, the flabellum diameter is not more than the axial flow DC fan of 90mm.

Background technique

Along with the increase of semiconductor integrated circuit number of transistors, the raising of switching frequency, the heating value of device (often being called chip) is also along with increase.The heating value of cpu chip in the computer, and the heating value of video card chip is occupied very big space to the dimension volume that makes the radiator on it greatly.Dwindle the computer volume, making it small and exquisite, compact subject matter is the size of dwindling radiator, makes it small and exquisite, compact.

Realize that small and exquisite, the compact approach of radiator has: reduce the size of cross-ventilation heat exchanger, reduce the size of fan.Encrypt the convection heat exchange fin, adopt and strengthen the cross-ventilation heat exchange structure, can effectively reduce the size of cross-ventilation heat exchanger, but improve the resistance of air flows greatly.If the blast of radiator fan is not enough, the air quantity of the heat exchange fin that will cause flowing through significantly descends, and the air temperature of the heat exchange fin of flowing through rises rapidly, and then the cross-ventilation heat transfer temperature difference descends, and its possibility of result causes heat dissipating capacity to descend.The blast height of centrifugal fan, but efficient is low, air quantity is little, and the volume of the centrifugal fan of equal air quantity is two or three times of axial flow.

What now generally adopt all is the single-stage axial fan, and only a few has add the one-level rectifier behind flabellum, and the design of blade profile is to be purpose with the ventilation, pursuit be high air quantity (no windage situation), blast is low.The fan that is used for electronic chip radiator, flabellum diameter are not more than 90mm (described flabellum diameter is meant the diameter at flabellum point place, and the flabellum of being called external diameter is also arranged) herein, belong to micro fan, and blast is lower.At heat dissipating capacity, the encryption fin of continuous rising, windage improves, the measure that existing people take: strengthen rotating speed; Strengthen the flabellum diameter.The former enlarged diameter of 65mm that is generally is to 85mm; Increase flabellum axial dimension (flabellum thickness is intended to increase fan blade area) and flabellum blade profile bent angle.These measures are simple and direct ways, and from aerodynamic force aspect deep study and analysis, effect is not undesirable, also brings other problems: strengthen the flabellum diameter, can improve air quantity and blast, but volume size increases noise, vibration increasing; Rotating speed increases, and noise and electrical machinery life problem are arranged again; Increase flabellum thickness, and the blade profile bent angle, air quantity and stagnation pressure when helping improving no windage, but in case windage is arranged, air quantity will descend rapidly, and this is that the relative flabellum angle of attack of air is excessive because aerodynamic quality is poor, the air-flow bending is excessive, flabellum back side airflow breakaway produces whirlpool, and the air flows loss increases rapidly, cause static pressure to descend rapidly, air quantity also just descends rapidly.

Summary of the invention

The utility model proposes a kind of miniature two-stage axial flow fan that is used for electronic chip radiator,, make it small and exquisite, the compact purpose that is to improve blast, to reduce fan dimension.

The technological scheme that the utility model adopted: fan is an axial flow, and critical piece has: flabellum, rectifier, motor, electric disc and clamshell; Motor is a brshless DC motor, and rotor, stator, circuit board, bearing housing, bearing and axle are wherein arranged, and rotor is a ring magnet, and stator is the silicon steel plate that is wound with coil.Of the present utility model being characterised in that: the two-stage flabellum is arranged, on drive hubs and driven wheel hub, between the flabellum of the two poles of the earth rectifier is arranged respectively, drive hubs is enclosed within on the rotor; The two-stage flabellum is by a motor driving, an axle center that is contained in drive hubs of axle, and driven wheel hub is contained in the other end of axle; Stator is fixedlyed connected with clamshell by bearing housing, electric disc and rectifier.

The two-stage flabellum is more superior than single-stage flabellum: the flabellum gross area doubles.Because wheel hub and all flabellums on it all are to adopt the mould single injection-molded, during for assurance punch and die folding interference must not be arranged, two adjacent blade axial directions must not have overlapping, thereby all chord of blade major axis mostly are the girth of flabellum most to the long sum of direction projection, if the blade profile bent angle of blade and established angle (angle of chord of foil and axis) are constant, then the fan blade area sum is constant, and is irrelevant with the flabellum axial width.If the one-level flabellum is divided into two-stage, blade profile bent angle and established angle are constant, the maximum fan leaf area sum of two-stage flabellum is the twice of one-level, that is to say that under the constant situation of total flabellum axial width, the one-level flabellum is divided into two-stage, the flabellum gross area also doubles, mean that flabellum drives air, to the air acting, the ability that the mechanical energy of motor is transported to air is doubled.

It is still not enough only to increase flabellum progression, rectifier (rectifier be exactly fixed, as the blade of flabellum sample) must be set between the two-stage flabellum, this is extremely important, and after air drove through first order flabellum, speed improved, but produce circumferential component velocity, air is spiral motion, and the effect of rectifier is exactly to reduce (elimination) circumferentially component velocity, and air slows down in the rectifier passage, that part of kinetic energy that speed is reduced converts pressure potential to, i.e. diffusion.If there is not rectifier, behind the first order flabellum, the circumferential component velocity of air is consistent with second level flabellum sense of rotation, then the speed of the relative second level of air flabellum reduces, the angle of attack is also little, and second level flabellum is also just little to the air acting like this, and air drives through the second level, circumferentially component velocity further improves, and spiral motion is stronger.The effect of fan is that big as far as possible air quantity promptly obtains high axial velocity; High as far as possible blast (mainly being static pressure).If this part kinetic energy of circumferential component velocity is not converted to pressure potential, circumferential speed is of no use, and spiral motion also causes serious flow losses on the contrary, has only the employing rectifier, could realize mechanical energy conversion efficiently.

The fixed installation of fan is to rely on clamshell, the bearing housing of support motor is fixed on the electric disc (or bearing housing and electric disc just be same working of plastics), electric disc is coupled to one by rectifier and clamshell, thereby, rectifier in the utility model not only plays a part the aerodynamic force aspect, also plays a part support motor.Electric disc in the existing fan is fixedlyed connected with clamshell, generally all adopts 4 spokes.Rectifier take greatly to 1/3rd fan shafts to width (fan thickness), spoke equally also will take partial width, that is to say, as long as increase fan thickness a bit (rectifier wide have more) than spoke, adopt the two-stage flabellum, the performance of fan can improve nearly one times, and the two-stage flabellum has a motor driving, and the cost cost of fan has also just improved a bit.

Below in conjunction with drawings and Examples the utility model is further specified.

Description of drawings

Fig. 1,2, the 3rd, the feature profile schematic representation of the utility model fan.

Fig. 4, the 5th, the feature profile schematic representation of multistage the utility model fan.

Among the figure, 1, drive hubs, 2, stator, 3, bearing housing, 4, rotor, 5, flabellum, 6, rectifier, 7, driven wheel hub, 8, axle, 9, bearing, 10, electric disc, 11, clamshell, 12, circuit board.

Embodiment

Fig. 1 shows the essential characteristic of the utility model fan, the stator of motor (2) drive fit is enclosed within on the bearing housing (3), in the bearing housing (3) bearing (9), an axle center that is inlaid in drive hubs (1) of axle (8), the rotor of motor (4) is a ring magnet, and drive hubs (1) is enclosed within on the rotor (4), and bearing housing (3) is fixed on the electric disc (10), and with electric disc (10) coaxial line, the circuit board (12) that electronic devices such as Hall are housed is between stator (2) and electric disc (10).These structures and existing minisize axial-flow formula brshless DC motor are similar, can adopt existing fan electromotor, as long as notice whether power mates.Different is: electric disc (10) is stretched out in the other end of axle (8), the driven wheel hub (7) that has flabellum (5) is contained on this axle that stretches out, the rotating magnetic field that stator (2) produces, driving rotor (4) rotates, be enclosed within the flabellum (5) that drive hubs (1) on the rotor (4) drives on it and rotate, and by axle (8) drive driven wheel hub (7) with and on flabellum (5) rotation.Between flabellum (5) on the drive hubs (1) and the flabellum (5) on the driven wheel hub (7) rectifier (6) is arranged, and rectifier (6) is fixedlyed connected electric disc (10) with clamshell (11), the power that electric disc (10) bears is delivered on the clamshell (11) by rectifier (6).

Because the motor output power will improve, motor axial width (mainly being the wide of rotor) will increase, but is enclosed within the axial reductions of epitrochanterian flabellum little (being divided into two flabellums), thereby rotor axial is wide bigger than the flabellum on it.In order to make the fan dimension compactness, thin thickness, rotor (4) reach in rectifier (6) root than the axial wide part that grows of flabellum on it, shown in Fig. 1 plants.During design, the part that should as far as possible rotor (4) be grown is placed in rectifier (6) root, but must consider the join strength of electric disc (10) and rectifier (6), the parts that rotate, as flabellum (5), drive hubs (1), and rotor (4) and rectifier (6) and root thereof will leave the gap, and contact friction must not be arranged.Clamshell (11), rectifier (6) and electric disc (10) are designed to an one-piece element, adopt Shooting Technique, single injection-molded, help like this guaranteeing that the interior circle of clamshell (11) is concentric with electric disc (10), guarantee that promptly flabellum (5) is even with the gap of the interior circle of clamshell, guarantee simultaneously the intensity that is connected and fixed of clamshell (11) and electric disc (10) again, reduce follow-up manufacturing process, enhance productivity.

The utility model fan shown in Figure 2, flabellum (5) on the drive hubs (1) is a first order air intake, at the other end, be outlet air end, have additional rectifier (6), total two-stage rectifier, the outer cover of the outer cover of second level flabellum (5) and outlet air end rectifier (6) is an one-piece element, can adopt Shooting Technique, single injection-molded, these are different with fan shown in Figure 1.Should be during design with the rectifier (6) of outlet air end and its outer cover as an one-piece element.In addition, the difference of Fig. 1 and Fig. 2 also has: bearing housing shown in Fig. 2 and electric disc are same one-piece element, can adopt Shooting Technique, single injection-molded, so more help proof strength and concentricity, guarantee that the gap between flabellum (5) and the outer cover inner round wall is even.

Fan shown in Figure 3 is with shown in Figure 2 similar, difference is: the flabellum (5) on the driven wheel hub (7) is a first order air intake, outlet air end also is provided with rectifier (6), in addition, drive hubs (1) and rotor (4) also extend in the root of rectifier (6) of outlet air end, She Ji purpose is to reduce fan thickness like this, makes compact structure.

Increase fan progression in order further to improve air quantity and blast, can to adopt, shown in Fig. 4,5.Fan shown in Figure 4 is on the basis of the utility model fan, increases the fan that an air opening end is provided with rectifier (6) at its intake grill end, that is to say, is superimposed as three grades of axial flow fans by two independent axial flow fans.Fig. 5 shows a kind of level Four axial flow fan, and being has two (as shown in Figure 1) of the present utility model fan stacks to form, and the centre is provided with rectifier.

From the aerodynamic force aspect and the compact aspect of fan dimension consider that single-stage flabellum axial width is as far as possible little in the fan, during design, should get single-stage flabellum axial width and the flabellum diameter ratio is not more than 0.12.If the blast of such two-stage axial flow fan is not enough, just can consider Fig. 4 or three grades or level Four shown in Figure 5, can obtain the fan design of small size, high blast like this, overcome the high windage that high density heat exchange fin, high enhanced heat exchange structure fin bring.

Claims

1. thermal fan for electronic chips, its flabellum diameter is not more than 90mm, is used on the electronic chip radiator, includes: clamshell (11), flabellum (5), rectifier (6), motor and electric disc (10), motor is a dc brushless motor, wherein has; Rotor (4), stator (2), bearing housing (3), bearing (9), axle (8), circuit board (12) is characterized in that: two-stage flabellum (5) is arranged, on drive hubs (1) and driven wheel hub (7), rectifier (6) is arranged between the two-stage flabellum (5) respectively; Drive hubs (1) is enclosed within on the rotor (4), an axle center that is contained in drive hubs (1) of axle (8), and driven wheel hub (7) is contained in the other end of axle (8); Stator (2) and bearing (9) are fixedlyed connected with clamshell (11) by bearing housing (3), electric disc (10) and rectifier (6).

2. fan according to claim 1 is characterized in that: rotor (2) has part to extend in the root of rectifier (6).

3. fan according to claim 1 and 2 is characterized in that: electric disc (10) and rectifier (6) and clamshell (11) are the unitary plastic part of an injection molded.

4. fan according to claim 1 and 2 is characterized in that: be provided with rectifier (6) at outlet air end.

5. fan according to claim 1 and 2 is characterized in that: the axial wide and ratio flabellum diameter of single-stage flabellum is not more than 0.12.