CN103104555A - Centrifugal fan - Google Patents

Abstract

A centrifugal fan includes an impeller and a housing. The impeller has an axis and a blade. The casing wraps the impeller, the casing is provided with an upper casing, a lower casing, at least one convex part and a first air inlet, wherein the convex part is arranged on at least one of the upper casing and the lower casing and is arranged around the fan blades, the first air inlet is arranged on the upper casing, the first air inlet is provided with a first area and a second area, and the radius of the first area is larger than that of the second area. The centrifugal fan can reduce the phenomenon of air backflow leakage pressure, and can increase the air inlet amount by adjusting the size of the air inlet so as to obtain the optimal heat dissipation effect.

Description

centrifugal fan

technical field

The invention relates to a fan, in particular to a centrifugal fan.

Background technique

With the rapid development of the electronics industry, more and more heat is generated by electronic components such as chips in electronic products. In order to effectively dissipate the excess heat, a heat sink is usually attached to the surface of the heating electronic component, and then a centrifugal fan is installed on the heat sink, and the cooling airflow generated by the centrifugal fan is used to forcibly dissipate heat from the heat sink, thereby dissipating heat Heat generated by electronic components is dissipated.

Please refer to FIG. 1A and FIG. 1B , wherein FIG. 1A is a top view of a centrifugal fan in the prior art, and FIG. 1B is a cross-sectional view of the centrifugal fan in FIG. 1A . The centrifugal fan 1 includes an impeller 11 and a casing 12 . The impeller 11 is disposed in the housing 12 , the impeller 11 is connected to the housing 12 via an axis 111 , and a fan blade 112 is disposed around the axis 111 . The casing 12 has an upper casing 121 and a lower casing 122 , the upper casing 121 is connected to the lower casing 122 , and the impeller 11 is disposed between the upper casing 121 and the lower casing 122 .

The surfaces of the upper and lower casings 121, 122 of the existing centrifugal fan are designed as a plane, and there is a gap between the fan blade 112 and the upper and lower casings 121, 122, so when the fluid pressure inside the fan increases to be greater than the external pressure, the fluid will pass through The gap overflows to the air inlets inside the upper and lower shells 121, 122 (as indicated by the arrows), so that the air intake decreases and the air output decreases, thereby affecting the overall heat dissipation performance.

Therefore, how to provide a centrifugal fan that can avoid air backflow and reduce the air intake, and can effectively guide the air to flow to the air outlet to increase the air output, so as to effectively improve the heat dissipation performance.

Contents of the invention

In view of the above problems, the purpose of the present invention is to provide a centrifugal fan that can reduce the phenomenon of air backflow leakage pressure, and can increase the air intake by adjusting the size of the air inlet, thereby obtaining the best heat dissipation effect.

To achieve the above objectives, the present invention provides a centrifugal fan including an impeller and a casing. The impeller has an axis and a blade. The casing covers the impeller, and the casing has an upper casing, a lower casing, at least one convex portion and a first air inlet, wherein the convex portion is arranged on at least one of the upper casing and the lower casing, and is arranged on the fan blade. Around, the first air inlet is arranged on the upper case, the first air inlet has a first area and a second area, the radius of the first area is larger than the radius of the second area.

In a preferred embodiment of the present invention, the casing further has an air outlet disposed between the upper casing and the lower casing.

In a preferred embodiment of the present invention, taking the axis as the center, the angle of the first region is less than 270 degrees.

In a preferred embodiment of the present invention, the protrusion is in the shape of a ring or an arc.

In a preferred embodiment of the present invention, the lower shell has a throat.

In a preferred embodiment of the present invention, the protrusion is disposed on the side of the upper case or the lower case close to the air outlet, and the protrusion may also be disposed on the side of the upper case or the lower case away from the air outlet.

In a preferred embodiment of the present invention, when the casing has a plurality of protrusions, the plurality of protrusions are respectively disposed on at least one of the upper case and the lower case.

Based on the above, the centrifugal fan of the present invention is provided with a convex portion at least one of the upper casing and the lower casing, and is arranged on the outside of the fan blade, so that the wind sent in from the air inlet can avoid being caused by the wind in the casing. air pressure and return to the outside world. In addition, multiple or different shapes of protrusions can be provided on the casing to apply to different environments, or to correspond to the application of centrifugal fans of different sizes. Furthermore, in the centrifugal fan of the present invention, the air inlet is provided with a first area and a second area, and the air intake volume of the centrifugal fan can be adjusted by adjusting the openings of the first area and the second area to be of different sizes.

Description of drawings

Figure 1A is a top view of a conventional centrifugal fan;

1B is a cross-sectional view of the centrifugal fan according to FIG. 1A;

2A is an exploded schematic view of a centrifugal fan according to a preferred embodiment of the present invention;

FIG. 2B is a combined schematic diagram of the centrifugal fan according to FIG. 2A;

2C is a top view of the centrifugal fan according to FIG. 2B;

FIG. 2D is a cross-sectional view of the centrifugal fan according to FIG. 2C;

3A and 3B are schematic diagrams of changes in the housing of the present invention;

4A to 4C are schematic diagrams of variations of the housing of the present invention; and

FIG. 5 is a schematic diagram of a variation of the centrifugal fan according to the present invention.

Wherein, the reference signs are explained as follows:

1, 2, 2a, 2b, 2c, 2d, 2e, 2f: centrifugal fan

11, 3: impeller

111, 31: axis

112, 32: fan blade

12, 4, 4a, 4b, 4c, 4d, 4e, 4f: housing

121, 41: upper shell

122, 42: lower shell

421: Throat

43, 43a: convex part

44: The first air inlet

441: First Area

442: Second Area

45: Second air inlet

46: Air outlet

A: Gap

B: height

L: baseline

θ: angle

Detailed ways

A centrifugal fan according to a preferred embodiment of the present invention will be described below with reference to related drawings, wherein the same components will be described with the same reference symbols.

Please refer to FIG. 2A to FIG. 2B , wherein FIG. 2A is an exploded schematic diagram of a centrifugal fan according to a preferred embodiment of the present invention; FIG. 2B is a schematic diagram of an assembly of the centrifugal fan according to FIG. 2A . The centrifugal fan 2 includes an impeller 3 and a casing 4 .

The impeller 3 has an axis 31 and a blade 32 . The fan blade 32 is arranged around the axis 31 . The impeller 3 is connected with the casing 4 through the shaft center 31 .

The casing 4 covers the impeller 3 , and the casing 4 has an upper casing 41 , a lower casing 42 , at least one protrusion 43 and a first air inlet 44 . The upper shell 41 and the lower shell 42 are arranged opposite to each other and connected to each other. In this embodiment, the impeller 3 is connected to the lower shell 42 of the casing 4 via the shaft center 31 .

Please refer to FIG. 2A to FIG. 2D at the same time, wherein FIG. 2C is a top view of the centrifugal fan according to FIG. 2B ; FIG. 2D is a cross-sectional view of the centrifugal fan according to FIG. 2C . The convex portion 43 is disposed on at least one of the upper shell 41 and the lower shell 42, and is disposed around the fan blade 32, wherein the convex portion 43 and the upper shell 41 or the lower shell 42 can be integrally formed components, or can be respectively As an independent component, the protrusion 43 is disposed on the upper case 41 or the lower case 42 , but it is not limited to the present invention. When the casing 4 has a plurality of protrusions 43, the plurality of protrusions 43 can be respectively arranged on the upper case 41 and the lower case 42, or the plurality of protrusions 43 are all arranged on the upper case 41 and the lower case 42. one of them. In addition, the shape of the convex part 43 can be ring shape, arc shape, straight line shape or other shapes. In the centrifugal fan 2 of this embodiment, the shell 4 has two ring-shaped protrusions 43 as an example, and the plurality of protrusions 43 are respectively disposed on the upper shell 41 and the lower shell 42 , but this is not intended to limit the present invention.

Please refer to FIG. 3A and FIG. 3B , which are schematic diagrams of variations of the casing of the present invention. The casing 4 a of the centrifugal fan 2 a is for example provided with an annular convex portion 43 , and the convex portion 43 is disposed on the lower casing 42 . The casing of the centrifugal fan 2 b also has an annular protrusion 43 , but the protrusion 43 is disposed on the upper case 41 .

2D, it is worth mentioning that there is a gap A between the fan blade 32 and the upper shell 41 or the lower shell 42, and the convex portion 43 has a height B, and the height B of the convex portion 43 is greater than 1/4. A gap A, for example, if the gap A is 0.4 centimeters, then the height B of the convex portion 43 should be greater than 0.1 centimeters, so as to prevent the air fluid flowing into the housing 4 from the first air inlet 44 from returning due to excessive internal pressure. outside world.

Referring again to FIG. 2A to FIG. 2C , the first air inlet 44 is disposed on the upper shell 41 . The first air inlet 44 in this embodiment has a first area 441 and a second area 442 , the radius of the first area 441 is greater than the radius of the second area 442 . In more detail, the centrifugal fan 2 of this embodiment can regard the axis 31 as the center of a circle, and the first air inlet 44 can be regarded as a circle, but it is an incomplete circle, wherein the opening of the first area 441 is relatively The radius of the first region 441 is not equal to the radius of the second region 442 . In this embodiment, the radius of the first region 441 is greater than the radius of the second region 442 as an example.

In addition, the casing 4 further has a second air inlet 45, which is arranged on the lower case 42 and is opposite to the first air inlet 44. The shape and size of the second air inlet 45 in this embodiment are the same as those of the first air inlet 44. and unequal in size.

The casing 4 further has an air outlet 46 disposed between the upper casing 41 and the lower casing 42 . The air outlet 46 is perpendicular to the first air inlet 44 and the second air inlet 45, and is used to discharge the air in the centrifugal fan 2 to dissipate heat from an electronic product.

The lower casing 42 has a throat 421. More specifically, the throat 421 is disposed on the side of the lower casing 42 close to the air outlet 46, and is also close to the fan blade 32, so that the air in the casing 4 moves counterclockwise. (shown in the drawing of FIG. 2A ) is discharged to the air outlet 46 .

It should be noted that the angle of the first area 441 of the first air inlet 44 plus the angle of the second area 442 is 360 degrees, wherein the angle θ of the first area 441 is less than 270 degrees. In more detail, as shown in FIG. 2C , with the axis 31 as the center and the axis 31 to the throat 421 as the reference line L, the range of the first region 441 is from the reference line L to the direction of the air outlet 46 (as indicated by the arrow (shown) within 270 degrees of rotation, that is, the first area 441 is preferably disposed within 270 degrees of clockwise rotation from the reference line L, so as to increase the air intake near the air outlet 46 side. In this embodiment, the first air inlet 44 is divided into multiple areas, and the openings of the multiple areas are not equal in size, so as to increase the air intake. In other embodiments, the first air inlet 44 can further have a third area or a fourth area to increase or decrease the size of the air inlet, and the air intake volume can also be adjusted according to different installation positions.

Please refer to FIG. 4A to FIG. 4C , which are schematic diagrams of variations of the casing of the present invention. As mentioned above, the shape of the convex portion can be ring-shaped, arc-shaped, linear or other shapes, and the convex portion can be disposed on the outer side of some fan blades. As shown in FIG. 4A, the shape of the convex portion 43a of the centrifugal fan 2c is an arc shape, and it is arranged on the side of the housing 4c close to the air outlet 46. The convex portion 43a can be respectively provided on the upper shell 41 and the lower shell. 42, and a protrusion 43a may also be disposed on one of the upper shell 41 or the lower shell 42. As shown in FIG. 4B , the protrusion 43 a of the centrifugal fan 2 d can also be disposed on a side of the casing 4 d away from the air outlet 46 . As shown in Figure 4C, the centrifugal fan 2e of the present invention can also be provided with a plurality of protrusions 43a on the casing 4e, and the plurality of protrusions 43a can be all arranged on one of the upper case 41 or the lower case 42, or They are respectively arranged on the upper case 41 and the lower case 42 .

Referring to FIG. 5 , it is a schematic diagram of a variation of the centrifugal fan of the present invention. The centrifugal fan 2f is provided with two air outlets 46 on the casing 4f, which are respectively arranged on both sides of the casing 4f. The casing 4f of this embodiment is provided with protrusions 43 on the upper casing 41 and the lower casing 42 . The centrifugal fan 2f of this embodiment can not only avoid the backflow of the airflow, increase the air intake, but also supply air to two directions at the same time, so as to increase the effect of heat dissipation. It should be noted that the angle θ of the first region 441 in this embodiment is also smaller than 270 degrees.

To sum up, the centrifugal fan of the present invention is provided with a convex portion on at least one of the upper shell and the lower shell, and is arranged on the outside of the fan blade, so that the wind sent in from the air inlet can avoid being caused by the wind in the shell. Air pressure will return to the outside world. In addition, multiple or different shapes of protrusions can be provided on the casing to apply to different environments, or to correspond to the application of centrifugal fans of different sizes. Furthermore, in the centrifugal fan of the present invention, the air inlet is provided with a first area and a second area, and the air intake volume of the centrifugal fan can be adjusted by adjusting the openings of the first area and the second area to be of different sizes.

Compared with the prior art, the centrifugal fan of the present invention can effectively guide the airflow to reduce the phenomenon of air backflow leakage pressure, and can increase the air intake by adjusting the size of the air inlet. In addition, the shape or location of the convex part can be adjusted or changed according to the environment of use or the air pressure inside the casing to increase the air intake and obtain the best heat dissipation effect.

The above description is for illustration only, not for limitation. Any equivalent modifications or changes made without departing from the spirit and scope of the present invention shall be included in the appended claims.

Claims (9)

1. A centrifugal fan, characterized in that, comprising: an impeller having a shaft and a blade; and A housing, the housing covers the impeller, the housing has an upper shell, a lower shell, at least one protrusion and a first air inlet, wherein the protrusion is arranged on at least the upper shell and the lower shell One of them is arranged around the fan blade, the first air inlet is arranged on the upper case, the first air inlet has a first area and a second area, the radius of the first area is larger than that of the second The radius of the area. 2. The centrifugal fan according to claim 1, wherein the casing further has an air outlet disposed between the upper casing and the lower casing. 3. The centrifugal fan as claimed in claim 1, wherein an angle of the first region is less than 270 degrees with the axis as the center. 4. The centrifugal fan as claimed in claim 1, wherein the protrusion is in the shape of a ring or an arc. 5. The centrifugal fan as claimed in claim 1, wherein the lower case has a throat. 6. The centrifugal fan according to claim 2, wherein the protrusion is disposed on a side of the upper shell or the lower shell close to the air outlet. 7. The centrifugal fan according to claim 2, wherein the protrusion is disposed on a side of the upper shell or the lower shell away from the air outlet. 8 . The centrifugal fan according to claim 1 , wherein the casing has a plurality of protrusions, and the plurality of protrusions are respectively disposed on at least one of the upper casing and the lower casing. 9. The centrifugal fan as claimed in claim 1, wherein the housing further has a second air inlet disposed on the lower housing.

Images