U.S. patent application number 12/763191 was filed with the patent office on 2011-06-23 for centrifugal fan.
This patent application is currently assigned to FU ZHUN PRECISION INDUSTRY (SHEN ZHEN) CO., LTD.. Invention is credited to JER-HAUR KUO, YE-FEI YU, XIN-XIANG ZHA.
Application Number | 20110150651 12/763191 |
Document ID | / |
Family ID | 44151368 |
Filed Date | 2011-06-23 |
United States Patent
Application |
20110150651 |
Kind Code |
A1 |
ZHA; XIN-XIANG ; et
al. |
June 23, 2011 |
CENTRIFUGAL FAN
Abstract
A centrifugal fan includes a housing including an air collecting
portion, a first frame and a second frame. The air collecting
portion has an air outlet defined in one end thereof. The first and
second frames are located at two opposite sides of an opposite end
of the air collecting portion. The first and second frames each
define a receiving space therein for rotatably receiving an
impeller. The first and second frames each further define a vent
hole therein. The receiving spaces of the first and second frames
communicate with the inner space of the air collecting portion via
the vent holes thereof. Airflow generated by the two impellers
travels to the inner space of the air collecting portion through
the vent holes of the first and second frames, and exits the
centrifugal fan through the air outlet of the air collecting
portion.
Inventors: |
ZHA; XIN-XIANG; (Shenzhen
City, CN) ; YU; YE-FEI; (Shenzhen City, CN) ;
KUO; JER-HAUR; (Tu-Cheng, TW) |
Assignee: |
FU ZHUN PRECISION INDUSTRY (SHEN
ZHEN) CO., LTD.
Shenzhen City
CN
FOXCONN TECHNOLOGY CO., LTD.
Tu-Cheng
TW
|
Family ID: |
44151368 |
Appl. No.: |
12/763191 |
Filed: |
April 19, 2010 |
Current U.S.
Class: |
416/120 |
Current CPC
Class: |
G06F 1/20 20130101; F04D
29/424 20130101; F04D 25/166 20130101 |
Class at
Publication: |
416/120 |
International
Class: |
F04D 1/00 20060101
F04D001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 23, 2009 |
CN |
200910312120.4 |
Claims
1. A centrifugal fan comprising: a housing comprising an air
collecting portion, the air collecting portion having an air outlet
defined in one end thereof; a first frame and a second frame
adjacent two opposite lateral sides of an opposite end of the air
collecting portion, respectively, the first frame defining a first
receiving space and a first vent hole therein, the second frame
defining a second receiving space and a second vent hole therein,
the receiving spaces of the first frame and the second frame
communicating with an inner space of the air collecting portion via
the first vent hole and the second vent hole, respectively; and a
first impeller rotatably received in the first receiving space and
a second impeller rotatably received in the second receiving space;
wherein airflow generated by the first impeller is guided to the
inner space of the air collecting portion via the first vent hole,
airflow generated by the second impeller is guided to the inner
space of the air collecting portion via the second vent hole, and
resulting airflow at the air collecting portion is expelled out of
the centrifugal fan through the air outlet of the air collecting
portion.
2. The centrifugal fan of claim 1, wherein the air collecting
portion comprises a bottom plate, a top plate and two guide plates
connected between the bottom plate and the top plate.
3. The centrifugal fan of claim 2, wherein the two guide plates are
parallel to each other, and a cross section of the air collecting
portion taken along a plane spanning from the top plate to the
bottom plate is rectangular.
4. The centrifugal fan of claim 3, wherein each of the first frame
and the second frame comprises a supporting plate, a cover plate,
and a volute side plate connecting between the supporting plate and
the cover plate, the first vent hole is defined in the side plate
of the first frame, the second vent hole is defined in the side
plate of the second frame, and the cover plates of the first frame
and the second frame each define an air inlet therein.
5. The centrifugal fan of claim 4, wherein a rear end of the side
plate of the first frame connects with a rear end of the side plate
of the second frame to form a connecting portion between the first
and second impellers, and front ends of the side plates of the
first frame and the second frame respectively connect with rear
ends of the two guide plates of the air collecting portion.
6. The centrifugal fan of claim 5, wherein the connecting portion
is outside the air collecting portion and faces the center of the
air collecting portion.
7. The centrifugal fan of claim 1, wherein the first frame and the
second frame are symmetrically disposed at the two opposite lateral
sides of the opposite end of the air collecting portion.
8. The centrifugal fan of claim 1, wherein the first frame and the
second frame are arranged at the two opposite sides of the opposite
end of the air collecting portion in an asymmetrical manner, with
the first frame being closer to the air outlet of the air
collecting portion than the second frame.
9. The centrifugal fan of claim 1, wherein an area of the air
outlet is less than a total area of the first vent hole and the
second vent hole.
10. The centrifugal fan of claim 1, wherein the first and second
impellers rotate in opposite directions.
Description
BACKGROUND
[0001] 1. Technical Field
[0002] The present disclosure generally relates to heat
dissipation, and particularly to a centrifugal fan for dissipating
heat from electronic components.
[0003] 2. Description of Related Art
[0004] With developments in technology, improved performance of
electronic components such as CPUs (central processing units) has
been achieved. However, such electronic components generate
increased levels of heat, which must be dissipated promptly.
Conventionally, a centrifugal fan is used to remove the generated
heat of the electronic components.
[0005] The centrifugal fan includes a housing and an impeller
rotatably mounted in the housing. The housing defines an air outlet
and an air inlet perpendicular to the air outlet. In operation, air
outside the housing of the centrifugal fan is pumped into the
housing via the air inlet thereof and then expelled out of the
housing by the impeller from the air outlet to take away the
generated heat of the electronic component. The efficiency of the
centrifugal fan is proportionate to an airflow volume and an
airflow pressure of the centrifugal fan. To increase airflow volume
and pressure, the rotation speed of the centrifugal fan can be
increased. However, such an increase normally also increases noise
generated by the centrifugal fan.
[0006] Therefore, what is needed is a centrifugal fan which can
overcome the described limitations.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is an isometric, assembled view of a first embodiment
of a centrifugal fan.
[0008] FIG. 2 is an exploded view of the centrifugal fan of FIG.
1.
[0009] FIG. 3 is an isometric, assembled view of a second
embodiment of a centrifugal fan.
[0010] FIG. 4 is an isometric view of a housing of the centrifugal
fan of FIG. 3.
DETAILED DESCRIPTION
[0011] Referring to FIGS. 1 and 2, a first embodiment of a
centrifugal fan is shown. The centrifugal fan 100 includes a hollow
housing 10, and a first impeller 20 and a second impeller 30 each
rotatably mounted in the housing 10.
[0012] The housing 10 includes an air collecting portion 40, and a
first frame 50 and a second frame 60 both connected at a rear of
the air collecting portion 40. The first frame 50 and the second
frame 60 are symmetrically disposed at two lateral sides of the
rear of the air collecting portion 40. An air outlet 41 is defined
in the front of the air collecting portion 40.
[0013] The air collecting portion 40 includes a bottom plate 42, a
top plate 43 and two guide plates 44 connected between the bottom
plate 42 and the top plate 43. The bottom plate 42 faces the top
plate 43. The two guide plates 44 are located at two opposite
lateral sides of the bottom plate 42, and are parallel to each
other. A cross section of the air collecting portion 40, taken in a
vertical plane, is rectangular.
[0014] The first and second frames 50, 60 each have a generally
round profile. The first frame 50 defines a first receiving space
51 therein for rotatably receiving the first impeller 20, and the
second frame 60 defines a second receiving space 61 therein for
rotatably receiving the second impeller 30.
[0015] The first frame 50 further defines a first vent hole 52
therein near the rear of the air collecting portion 40, and the
second frame 60 further defines a second vent hole 62 therein near
the rear of the air collecting portion 40. The first vent hole 52
and the second vent hole 62 each communicate with the inner space
of the air collecting portion 40. Airflow generated by the first
impeller 20 and the second impeller 30 is guided and collected via
the first and second vent holes 52, 62 to the inner space of the
air collecting portion 40, and then exits the centrifugal fan 100
from the air outlet 41 of the air collecting portion 40. An area of
the air outlet 41 is less than a total area of the first vent hole
52 and the second vent hole 62.
[0016] Each of the first frame 50 and the second frame 60 includes
a supporting plate 71, a cover plate 72, and a volute side plate 73
connecting between the supporting plate 71 and the cover plate 72.
The side plate 73 extends upwardly and perpendicularly from an
outer periphery of the supporting plate 71. The first vent hole 52
is defined in the side plate 73 of the first frame 50, and the
second vent hole 62 is defined in the side plate 73 of the second
frame 60. The cover plates 72 of the first frame 50 and the second
frame 60 each define an air inlet 74 therein. The air inlets 74 of
the first frame 50 and the second frame 60 are located above and
concentric with the first impeller 20 and the second impeller 30,
respectively.
[0017] A rear end of the side plate 73 of the first frame 50
connects with a rear end of the side plate 73 of the second frame
60 to form a connecting portion 75 at a rear of the air collecting
portion 40. The connecting portion 75 is located between the first
impeller 20 and the second impeller 30, and an end face of the
connecting portion 75 faces the center of the air collecting
portion 40. Front ends of the side plates 73 of the first frame 50
and the second frame 60 are spaced apart from each other, and
connect with rear ends of the two guide plates 44 of the air
collecting portion 40, respectively.
[0018] Each of the first impeller 20 and the second impeller 30
includes a cylindrical hub 21 and a plurality of blades 22
extending tangentially from the periphery of the hub 21. The hubs
21 of the first and second impellers 20, 30 are rotatably mounted
on the supporting plates 71 of the first and second frames 50, 60,
respectively. Each of the blades 22 is a straight strip-shaped
plate and perpendicular to the supporting plate 71. A distance
between the first impeller 20 and the air outlet 41 of the air
collecting portion 40 is equal to that between the second impeller
30 and the air outlet 41 of the air collecting portion 40.
[0019] During operation of the centrifugal fan 100, a rotation
direction of the first impeller 20 is different from (i.e.,
opposite to) that of the second impeller 30. In this embodiment,
the first impeller 20 rotates clockwise and the second impeller 30
rotates counterclockwise. Air is drawn into the housing 10 through
the two air inlets 74 of the cover plates 72 of the first frame 50
and the second frame 60, and the resulting airflow is accelerated
and expelled by the first impeller 20 and the second impeller 30
out of the first frame 50 and the second frame 60 via the first and
second vent holes 52, 62 towards the inner space of the air
collecting portion 40. Airflow from the first frame 50 and the
second frame 60 is combined in the air collecting portion 40, and
exits the centrifugal fan 100 from the air outlet 41 of the air
collecting portion 40.
[0020] In the centrifugal fan 100, airflow is driven by the first
impeller 20 and the second impeller 30, and airflow from the first
frame 50 and the second frame 60 is combined in the air collecting
portion 40, such that airflow out of the air outlet 41 of the air
collecting portion 40 has high volume and pressure. Such high
volume and pressure can be achieved even when the first and second
impellers 20, 30 of the centrifugal fan 100 rotate at a relatively
low speed, thus providing efficient operation with reduced noise.
In this embodiment, the first and second impellers 20, 30 rotate at
the same speed. Understandably, the first and second impellers 20,
30 can instead rotate at different speeds to provide an adjustable
volume and pressure.
[0021] FIGS. 3 and 4 show a second embodiment of a centrifugal fan
100a. The centrifugal fan 100a differs from the centrifugal fan 100
of the previous embodiment only in that a first frame 50a and the
second frame 60 are arranged at two opposite sides of a rear of the
air collecting portion 40a in an asymmetrical manner. That is, the
first frame 50a is closer to the air outlet 41 of the air
collecting portion 40a than the second frame 60. The first impeller
20 is closer to the air outlet 41 of an air collecting portion 40a
than the second impeller 30, and a guide plate 44a of the air
collecting portion 40a which connects with the side plate 73 of the
first frame 50a is shorter than the guide plate 44 of the air
collecting portion 40a which connects with the side plate 73 of the
second frame 60. In operation of the centrifugal fan 100a, an
average angle of airflow out of a first vent hole 52a of the first
frame 50a is different from that of the airflow out of the second
vent hole 62 of the second frame 60, thus reducing noise generated
by resonance of airflow. Furthermore, airflow from the second vent
hole 62 is accelerated by airflow from the first vent hole 52a,
increasing airflow pressure of the centrifugal fan 100a.
[0022] It is to be understood, however, that even though numerous
characteristics and advantages of the present embodiments have been
set forth in the foregoing description, together with details of
the structures and functions of the embodiments, the disclosure is
illustrative only, and changes may be made in detail, especially in
matters of shape, size, and arrangement of parts within the
principles of the invention to the full extent indicated by the
broad general meaning of the terms in which the appended claims are
expressed.
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