CN101105180A - Heat radiation fan - Google Patents

Abstract

The invention provides a heat radiation fan, which comprises an outer frame; a first rotor having a drive shaft and a plurality of moving blades; a second rotor coupled to the first rotor and having a plurality of moving blades; a base arranged in the outer frame for receiving the first and second rotors; and a plurality of stationary blades arranged between the outer frame and the base, wherein the rear end parts of the stationary blades extend along the axial direction of the heat dissipation fan, so that the working capacity of the second rotor is increased.

Description

cooling fan

technical field

The invention relates to a cooling fan, which improves the efficiency of the fan by optimizing the design between the moving and stationary blades.

Background technique

With the vigorous development of the electronic industry, the heat generated by electronic components is gradually increasing, and the previous method of using natural convection to solve waste heat has gradually become insufficient. At this time, cooling fans provide an excellent choice, so cooling fans have become an indispensable element in current electronic products.

At present, the efficiency of commonly used fans is about 15-30%, but in the era of energy saving, such efficiency performance is really unsatisfactory, especially for low-efficiency fans, energy loss is converted into waste heat, this waste heat It will be transmitted to the system environment, and this result will further weaken the heat dissipation effect of the fan, thus requiring a fan with a larger wattage, which will undoubtedly form a vicious circle in terms of energy usage. The conventional fan shown in FIG. 1 includes a frame 10 , a motor 12 , a base 15 and a rotor, wherein the base 15 is connected to the frame 10 through a support rod 14 and supports the motor 12 ; In the past, the method of expelling waste heat was nothing more than adopting the method of exposing the iron shell 11 of the rotor, in order to remove the waste heat by increasing the exposed heat dissipation area of the iron shell. However, this method is often insufficient when the motor 12 is getting smaller and smaller but the characteristic requirements are higher.

In addition, from the point of view of fan optimization, the optimal efficiency of the blades 13 of the rotor should theoretically be between 75% and 85%, but the overall efficiency of current electronic fans is about 15% to 30%. After deducting the loss of motor efficiency, the efficiency of the blade 13 is only between 20% and 45%, which is very different from the theoretical value. From the point of view of energy saving, there is room for improvement in this type of fan.

Therefore, in view of the lack of prior art, the present invention finally created the "radiating fan" of this case through careful testing and research and the spirit of perseverance. The following is a brief description of the case.

Contents of the invention

The main purpose of the present invention is to provide a heat dissipation fan, which has an optimized heat dissipation efficiency through the height ratio of the rotor moving blades to the stationary blades, the matching of the number of the moving and stationary blades, and the airfoil design of the stationary blades.

According to a concept of the present invention, the cooling fan includes an outer frame; a first rotor having a transmission shaft and a plurality of moving blades; a second rotor coupled with the first rotor and having a plurality of moving blades; a base, arranged in the outer frame, to receive the first and second rotors; and a plurality of stator blades, arranged between the outer frame and the base, wherein the rear ends of the stator blades follow The axial direction of the cooling fan is extended to increase the working capacity of the second rotor.

Preferably, the rear end of the stator blade accounts for 1/3 to 1/4 of the length of the entire stator blade. The front end of the stator blade is curved.

The second rotor is arranged on the leeward side of the first rotor, wherein one end of the drive shaft extends through the top surface of the hub of the second rotor and is fixedly connected thereto. The fixing method is riveting, screwing, bonding or equivalent connection. The first rotor and the second rotor rotate at the same speed.

In addition, the cooling fan further includes a first airflow guiding cover, which is arranged on one side of the outer frame; and a second airflow guiding cover, which is arranged on the other side of the outer frame, wherein the second airflow guiding cover The boot cover further includes a plurality of stator blades disposed therein. The peripheral edge of the first airflow guide cover or the second airflow guide cover is inclined and flared or trumpet-shaped. The first airflow guide cover, the second airflow guide cover and the outer frame can be combined by clamping, riveting, screwing, bonding or equivalent means.

The first rotor and the second rotor further include a hub respectively, and the plurality of moving blades are arranged around the hub, wherein the hub of the first rotor is conical, hat-shaped, or has an inclined surface, and the first rotor The moving blades are upward and inclined. The interior of the hub of the second rotor is in the shape of a hollow cup. . Preferably, the hubs of the first rotor and the second rotor are respectively formed with a plurality of cooling holes, when the cooling fan rotates, the airflow passes through the cooling holes to produce a forced convection effect on the driving device, wherein the cooling holes The inner wall is inclined.

Preferably, the number of moving blades of the first rotor and the second rotor are different. More preferably, the first rotor has nine moving blades, and the second rotor has eight or five moving blades. Alternatively, the number of moving blades of the first rotor is 8, and the number of moving blades of the second rotor is 9 or 5. And the number of the stator blades is seven.

Preferably, the height ratio of the moving blades of the first rotor and the second rotor to the height of the stationary blades is 1:1.1-1.4, more preferably, the height ratio is 1:1.6-2.2.

In addition, the outer frame further includes a plurality of lugs, and the cooling fan is fixed on an external system frame through the holes on the lugs.

Moreover, the cooling fan includes a driving device, which is passed through the base and received by the base, and is used to drive the first and second rotors.

According to another conception of the present invention, the cooling fan includes an outer frame; a first rotor having a transmission shaft and a plurality of moving blades; a second rotor coupled with the first rotor and having a plurality of moving blades ; a base, arranged in the outer frame, to receive the first and second rotors; and a plurality of stator blades, arranged between the outer frame and the base, wherein the first rotor and the second The ratio of the height of the moving blade of the rotor to the height of the stationary blade is 1:1.1-2.2.

The present invention can be understood more deeply through the detailed description of the following drawings and examples.

Description of drawings

Fig. 1 is a schematic sectional view of an existing fan;

2 is a schematic cross-sectional view of a first preferred embodiment of the cooling fan of the present invention;

Fig. 3A, Fig. 3B and Fig. 3C are top views of the first rotor, stator blades and second rotor in Fig. 2 .

Fig. 4 is a schematic cross-sectional view of the moving blades of the first rotor, the stationary blades and the moving blades of the second rotor in Fig. 2;

FIG. 5 is an exploded perspective view of a second preferred embodiment of the cooling fan of the present invention.

Description of main component symbols

11: Iron shell 12: Motor

13: blade 14: support rod

21: Frame 22: Base

23, 41: Static blade 24: First rotor

25: Driving device 26: Transmission shaft

27: Second rotor 241, 271: Hub

242, 272: cooling holes 3: the first airflow guide cover

4: Second airflow guide cover 211: Lugs

243, 273: moving blade

Detailed ways

First, please refer to FIG. 2 , which shows a first preferred embodiment of the cooling fan of the present invention. The radiating fan includes an outer frame 21; a base 22, arranged in the outer frame 21; a plurality of stator blades 23, arranged between the base 22 and the outer frame 21; a first rotor 24; a drive A device 25 (such as a motor) passes through the base and is received by the base 22; a transmission shaft 26; and a second rotor 27, wherein the second rotor 27 is arranged at the rear end of the first rotor 24 (That is, the leeward side), one end of the drive shaft 26 extends through the top surface of the hub 271 of the second rotor 27 to be fixedly connected thereto, and the hub 271 of the second rotor 27 has a hollow cup shape inside. The transmission shaft 26 and the second rotor 27 may be connected by riveting, screwing, bonding or equivalent methods. Therefore, through the transmission shaft 26, the driving device 25 can drive the first rotor 24 and the second rotor 27 simultaneously, which can ensure that the first rotor 24 and the second rotor 27 rotate at the same speed.

In addition, a plurality of cooling holes 242, 272 are respectively formed on the hub top surfaces of the first rotor 24 and the second rotor 27. When the first rotor 24 and the second rotor 27 are rotated by the driving device 25, the airflow It will be sucked through the plurality of cooling holes 242, 272 (shown in dotted lines among the figures) on the hubs of the first rotor 24 and the second rotor 27 in order to dissipate the heat generated when the driving device 25 is in operation. , to increase the service life of the driving device 25. The first rotor 24 and the second rotor 27 respectively have a plurality of moving blades 243, 273, wherein the moving blades 243 of the first rotor 24 can be inclined upward, and the wind inlet side of the outer frame 21 has a flared portion 211, to increase the air intake.

In the design part of the height ratio between the moving blade and the stationary blade, firstly, from the point of view of fluid mechanics, because the fan forms a pressure difference through the rotation of the moving blade, the air flow is caused, but the rotation of the moving blade will drive the air flow, so the air flow in When flowing out of the fan, there will be an angular velocity in the direction of its velocity, which will cause energy loss for the efficiency of the fan; Many large and small eddy currents will be generated to cause energy loss; thirdly, the fluid passing through the solid surface will generate shear force due to friction, resulting in energy loss, and the gap between the tip of the moving blade and the wall of the outer frame will also cause secondary energy loss of the fluid. The present invention utilizes the Taguchi method to obtain the optimal design ratio between the moving and stationary blades. Among the parameters obtained, the height ratio of the moving and stationary blades is an important factor, and the effect of the stationary blades 23 is to guide the airflow, make the airflow smoother, reduce the generation of eddy currents, and guide the energy in the direction of angular velocity to the axial direction to perform work, so that the fan Efficiency is better. From the Taguchi method, the ratio of the height h2 of the moving blade 243 to the height h1 of the stationary blade 23 is 1: 1.6 to 2.2, the fan efficiency is the highest and the space utilization rate is the best, and the overall fan efficiency of the present invention can reach 45%, if the loss of the motor is deducted, the efficiency of the blades is about 60%, so the design of the present invention is far superior to the existing fans. Alternatively, the ratio of the height of the moving blades of the first rotor and the second rotor to the height of the stationary blades may also be 1:1.1˜1.4.

In the matching part of the number of moving and stationary blades, the number of moving blades of the first rotor 24 and the second rotor 27 is different, for example, the former is 8, while the latter is 9 or 5, and the number of moving blades is 7, as shown in Fig. 3A-Fig. As shown in 3C, the generation of noise can be reduced. Alternatively, the number of moving blades of the first rotor is nine, and the number of moving blades of the second rotor is eight or five.

In the part of the airfoil design of the stator blades, the stator blades 23 in the outer frame 21 can increase the working capacity of the second rotor 27 to provide the effect of airflow boosting. Preferably, the tail end of the stator blade 23 can be a vertical blade design, as shown in Figure 4, the front end 23a is a curved design, and the rear end 23b is a vertical design, that is, along with the fan The central axis extends in parallel, which can further increase the working capacity of the second rotor 27 at the rear end. In particular, in the present invention, the blade shape of the rear end of the stator blade 23 at about 1/3 to 1/4 of the overall length is parallel to the direction of the central axis, and adopts the type of vertical guide vane, which can improve the work efficiency of the blade at the rear end, so that The overall fan efficiency is optimized.

Please also refer to FIG. 5 , which shows a second preferred embodiment of the cooling fan of the present invention. Its structure is similar to that of the above-mentioned first preferred embodiment, the difference between the two is that the top surface of the hub of the first rotor 24 is conical, hat-shaped or inclined, and the inner walls of the cooling holes 242, 272 are inclined . In addition, the cooling fan further includes a first airflow guiding cover 3 and a second airflow guiding cover 4 respectively disposed on opposite sides of the outer frame 21 . Moreover, a plurality of stator blades 41 can be further provided in the second airflow guiding cover 4 , and when the airflow passes through, the effect of pressurization can be achieved again, so as to improve the overall heat dissipation efficiency. Of course, it is also possible to add a plurality of stator blades in the first airflow guiding cover 3 . The peripheral edges of the first airflow guide cover 3 and the second airflow guide cover 4 are preferably in the shape of an inclined flare or a trumpet shape. The first airflow guide cover 3 , the second airflow guide cover 4 and the outer frame 21 can be combined by clamping, riveting, screwing, bonding or equivalent means. In addition, the outer frame 21 includes a plurality of lugs 211 , and the cooling fan can be fixed on an external system frame through holes in the lugs 211 .

To sum up the above, the heat dissipation fan provided by the present invention achieves the optimal heat dissipation efficiency through the height ratio of the moving blades and the stationary blades of the rotor, the number of moving and stationary blades, and the design of the airfoil of the stationary blades, and can effectively use the space. Reach the balance point between the efficiency gain and profit and loss of the stator blades.

Although the present invention has been described with reference to the preferred embodiments above, the present invention is not limited thereto, and those skilled in the art can make various improvements and modifications to the present invention without departing from the spirit and scope of the present invention.

Claims (21)

1. radiation fan, it comprises:

One housing;

One the first rotor has a transmission shaft and a plurality of moving vane;

One second rotor couples with this first rotor, and has a plurality of moving vanes;

One pedestal is arranged in this housing, in order to accept this first and second rotor; And

A plurality of stator blades are arranged between this housing and this pedestal, and wherein the rearward end of this stator blade increases the acting ability of this second rotor along with the axial direction of this radiation fan extends.

2. radiation fan as claimed in claim 1, wherein the moving vane height of this first rotor and this second rotor and the aspect ratio of this stator blade are 1: 1.1～1.4 or are 1: 1.6～2.2.

3. radiation fan as claimed in claim 1, wherein the front end of this stator blade is bent arc.

4. radiation fan, it comprises:

One housing;

One the first rotor has a transmission shaft and a plurality of moving vane;

One second rotor couples with this first rotor, and has a plurality of moving vanes;

One pedestal is arranged in this housing, in order to accept this first and second rotor; And

A plurality of stator blades are arranged between this housing and this pedestal, and wherein the moving vane height of this first rotor and this second rotor and the aspect ratio of this stator blade are 1: 1.1～2.2.

5. as claim 1 or 4 described radiation fans, wherein an end of this transmission shaft extends through the wheel hub end face of this second rotor and is affixed with it.

6. radiation fan as claimed in claim 5, wherein this affixed mode be riveted, screw togather, bonding or equivalent way connect.

7. as claim 1 or 4 described radiation fans, it more comprises one first air-flow guiding cover, is arranged at a wherein side of this housing.

8. radiation fan as claimed in claim 7, it more comprises one second air-flow guiding cover, is arranged at the opposite side of this housing.

9. radiation fan as claimed in claim 8, wherein this second air-flow guiding cover more comprises a plurality of stator blades, is arranged in it.

10. radiation fan as claimed in claim 8, wherein this first air-flow guiding cover or this second air-flow guiding cover periphery are inclined external expanding shape or horn-like, this first air-flow guiding cover and this second air-flow guiding cover and this housing can by engage, riveted, screw togather, bonding or equivalent way make up.

11. as claim 1 or 4 described radiation fans, wherein this first rotor and second rotor comprise a wheel hub more respectively, these a plurality of moving vanes are located on around this wheel hub.

12. radiation fan as claimed in claim 11, wherein the wheel hub of this first rotor is coniform, bamboo hat shape or has skewed surface.

13. radiation fan as claimed in claim 11, wherein the wheel hub of this first rotor and this second rotor is formed with a plurality of radiation holes respectively, and when this radiation fan rotated, air communication was crossed this each radiation hole and this drive unit is produced the forced convection effect.

14. radiation fan as claimed in claim 13, wherein the inwall of this radiation hole is skewed.

15. as claim 1 or 4 described radiation fans, wherein the rotating speed of this first rotor and this second rotor is identical, the moving vane number of this first rotor and this second rotor is different.

16. as claim 1 or 4 described radiation fans, wherein the moving vane number of this first rotor is 9, and the moving vane number of this second rotor is 8 or 5, and perhaps the moving vane number of this first rotor is 8, the moving vane number of this second rotor is 9 or 5, and the number of this stator blade is 7.

17. as claim 1 or 4 described radiation fans, wherein the moving vane of this first rotor be raise up skewed.

18. as claim 1 or 4 described radiation fans, wherein this housing also comprises a plurality of lugs, by the hole on this lug this radiation fan is fixed on the external system frame.

19. as claim 1 or 4 described radiation fans, it more comprises a drive unit, is arranged in this pedestal and is accepted by this pedestal, in order to drive this first and second rotor.

20. radiation fan as claimed in claim 4, wherein the front end of this stator blade is bent arc, and the rearward end of this stator blade is along with the axial direction extension of this radiation fan.

21. as claim 1 or 4 described radiation fans, wherein the rearward end of this stator blade accounts for 1/3 to 1/4 of whole stator blade length.

Images