U.S. patent application number 12/748447 was filed with the patent office on 2011-07-21 for centrifugal fan and impeller thereof.
This patent application is currently assigned to Fu Zhun Precision Industry (Shen Zhen) Co., Ltd.. Invention is credited to CHIEN-LONG HONG, EN-MING LIANG, FANG-XIANG YU.
Application Number | 20110176916 12/748447 |
Document ID | / |
Family ID | 44266397 |
Filed Date | 2011-07-21 |
United States Patent
Application |
20110176916 |
Kind Code |
A1 |
LIANG; EN-MING ; et
al. |
July 21, 2011 |
CENTRIFUGAL FAN AND IMPELLER THEREOF
Abstract
A centrifugal fan includes a housing defining an inner space
therein and an impeller rotatably received in the inner space of
the housing. The impeller includes a hub, a blade ring surrounding
the hub, a plurality of first blades extending from the hub to the
blade ring, and a plurality of second blades extending from the
blade ring. Each first blade includes an inner portion between the
hub and the blade ring, and an outer portion extending from the
blade ring. The second blades and the outer portions of the first
blades are arranged in alternating fashion along a circumferential
direction of the blade ring. In each pair of an outer portion and
an adjacent second blade, the outer portion and the second blade
are curved outwards away from each other toward substantially
opposite directions.
Inventors: |
LIANG; EN-MING; (Shenzhen
City, CN) ; YU; FANG-XIANG; (Shenzhen City, CN)
; HONG; CHIEN-LONG; (Tu-Cheng, TW) |
Assignee: |
Fu Zhun Precision Industry (Shen
Zhen) Co., Ltd.
Shenzhen City
CN
Foxconn Technology Co., Ltd.
Tu-Cheng
TW
|
Family ID: |
44266397 |
Appl. No.: |
12/748447 |
Filed: |
March 28, 2010 |
Current U.S.
Class: |
415/203 ;
416/175 |
Current CPC
Class: |
F04D 29/281 20130101;
G06F 1/203 20130101; F04D 29/663 20130101; F04D 29/30 20130101;
F04D 25/0613 20130101 |
Class at
Publication: |
415/203 ;
416/175 |
International
Class: |
F04D 29/30 20060101
F04D029/30 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 16, 2010 |
CN |
201010300375.1 |
Claims
1. A centrifugal fan, comprising: a housing defining an inner
space, an air inlet and an air outlet therein, the inner space
communicating with the air inlet and air outlet, the air inlet
being substantially perpendicular to the air outlet; and an
impeller rotatably received in the housing, the impeller comprising
a hub, a blade ring surrounding the hub, a plurality of first
blades extending from the hub to the blade ring, and a plurality of
second blades on the blade ring, outer portions of the first blades
on the blade ring and the second blades being curved such that each
second blade and a corresponding adjacent outer portion of the
first blade are oriented generally symmetrically opposite each
other.
2. The centrifugal fan of claim 1, wherein the first blades and the
second blades are arranged in alternating fashion along a
circumferential direction of the blade ring.
3. The centrifugal fan of claim 2, wherein the outer portions of
the first blades on the blade ring are arc-shaped and the second
blades are arc-shaped, each second blade and the corresponding
adjacent outer portion of the first blade forming a profile of a
pair of parentheses.
4. The centrifugal fan of claim 1, wherein the outer portions of
the first blades curve outwards generally toward a rotation
direction of the centrifugal fan, and the second blades curve
outwards generally away from the rotation direction of the
centrifugal fan.
5. The centrifugal fan of claim 4, wherein each first blade further
comprises an inner portion extending from the hub to the outer
portion.
6. The centrifugal fan of claim 5, wherein the inner portion of the
first blade extends outwards generally away from the rotation
direction of the centrifugal fan.
7. The centrifugal fan of claim 5, wherein the inner portion of the
first blade is straight.
8. The centrifugal fan of claim 1, wherein the housing comprises
two covers arranged parallel to each other, and a sidewall
interconnecting the two covers, the air inlet being defined in the
two covers, the air outlet being defined in the sidewall, and
wherein the blade ring, the second blades, and the outer portions
of the first blades are aligned with the covers, and other portions
of the first blades and the hub are aligned with the air inlet.
9. The centrifugal fan of claim 1, wherein the hub comprises a
circular wall and an annular wall extending perpendicularly from a
periphery of the circular wall, an end of the annular wall farthest
from the circular wall being substantially coplanar with the blade
ring.
10. An impeller, comprising: a hub comprising a circular wall and
an annular wall extending from a periphery of the circular wall; a
blade ring surrounding and spaced from the annular wall of the hub;
a plurality of first blades extending outwards from the hub to the
blade ring, each first blade comprising an inner portion between
the annular wall of the hub and the blade ring, and an outer
portion extending from the blade ring; and a plurality of second
blades extending from the blade ring, the second blades and the
outer portions of the first blades being arranged in alternating
fashion along a circumferential direction of the blade ring,
wherein in each pair of an outer portion and an adjacent second
blade, the outer portion and the second blade are curved outwards
away from each other toward substantially opposite directions.
11. The impeller of claim 10, wherein the outer portions of the
first blades and the second blades are arc-shaped, and the each
pair of an outer portion and an adjacent second blade form a
profile of a pair of parentheses.
12. The impeller of claim 10, wherein the inner portion of the
first blade is straight.
13. The impeller of claim 10, wherein the blade ring is
substantially coplanar with an end of the annular wall farthest
from the circular wall.
14. The impeller of claim 10, wherein the second blades and the
outer portions of the first blades extend perpendicularly from the
same side of the blade ring.
Description
BACKGROUND
[0001] 1. Technical Field
[0002] The present disclosure relates generally to centrifugal
fans, and more particularly to an impeller of a centrifugal
fan.
[0003] 2. Description of Related Art
[0004] Generally, cooling fans are used in combination with heat
sinks for cooling electronic components, such as CPUs. Most
portable electronic systems that contain electronic components,
such as laptop computers and notebook computers, have limited space
therein. Thus a centrifugal fan which requires only a small space
for installation is generally used in such electronic systems.
[0005] In use of the centrifugal fan, an impeller of the
centrifugal fan rotates to generate an airflow to the electronic
component, and thereby continuously take away heat of the
electronic component. In order to improve the cooling and heat
dissipation efficiency, the most direct and effective way is to
increase the revolving speed of the impeller, thereby increasing
the flow rate of the airflow. However, increasing the revolving
speed of the impeller generally causes a noise level generated by
the centrifugal fan to also be increased. This may annoy or cause
discomfort to a user near the centrifugal fan.
[0006] What is needed, therefore, is a centrifugal fan with an
improved impeller to overcome the above-described limitations.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is an isometric, assembled view of a centrifugal fan,
according to an exemplary embodiment.
[0008] FIG. 2 is an exploded view of FIG. 1.
[0009] FIG. 3 is an enlarged view of an impeller of the centrifugal
fan shown in FIG. 2.
DETAILED DESCRIPTION
[0010] Referring to FIG. 1, a centrifugal fan according to an
exemplary embodiment is shown. The centrifugal fan includes a
housing 12 and an impeller 14 rotatably received in the housing
12.
[0011] Referring also to FIG. 2, the housing 12 includes a top
cover 120, a bottom cover 122, and a sidewall 124 interconnecting
outer peripheries of the top cover 120 and the bottom cover 122.
The top cover 120, the bottom cover 122 and the sidewall 124
cooperatively define an inner space 126 for receiving the impeller
14 therein. In this embodiment, the sidewall 124 is integrally
formed with the top cover 120. A first air inlet 121 is defined in
a central portion of the top cover 120, and a second air inlet 123
is defined in a central portion of the bottom cover 122. The first
air inlet 121 and the second air inlet 123 are coaxial. An air
outlet 131 is defined in the sidewall 124 of the housing 12, and is
oriented perpendicular to the first air inlet 121 and the second
air inlet 123.
[0012] A circular supporting base 127 is arranged in a central
portion of the second air inlet 123 of the bottom cover 122. A
plurality of ribs 128 extend outwards from the supporting base 127
to connect an inner periphery of the bottom cover 122, thus fixing
the supporting base 127 to the bottom cover 122. A tube 129 extends
perpendicularly from a central portion of the supporting base 127
towards the top cover 120. A bearing 130 is received in the tube
129 for supporting rotation of the impeller 14.
[0013] Referring also to FIG. 3, the impeller 14 includes a hub
140, a blade ring 144, a plurality of first blades 142, and a
plurality of second blades 146. In this embodiment, the blade ring
144, the first blades 142, the second blades 146 and the hub 140
are integrally formed by an injection molding process as a single
monolithic piece. The hub 140 includes a circular wall 141, and an
annular wall 143 extending perpendicularly downward from a
periphery of the circular wall 141. The blade ring 144 surrounds
and is spaced from the annular wall 143 of the hub 140. A bottom
side of the annular wall 143 is substantially coplanar with the
blade ring 144.
[0014] The first blades 142 extend outwards from an outer
circumferential surface of the annular wall 143 of the hub 140 to
the blade ring 144, and are evenly arranged along a circumferential
direction of the annular wall 143. Each first blade 142 includes a
straight inner portion 145 and a curved outer portion 147. The
inner portion 145 extends from an outer circumferential surface of
the annular wall 143 of the hub 140 to an inner edge of blade ring
144, while the outer portion 147 extends outwards from the inner
portion 145 to an outer edge of the blade ring 144. That is, the
inner portions 145 of the first blades 142 are located between the
annular wall 143 and the blade ring 144, while the outer portions
147 are entirely arranged on the blade ring 144 with bottom sides
thereof integrally joined with a top side of the blade ring
144.
[0015] The second blades 146 are evenly arranged along a
circumferential direction of the blade ring 144, with bottom sides
thereof integrally joined with the top side of the blade ring 144.
The second blades 146 and the outer portions 147 of the first
blades 142 are arranged in an alternating fashion along a
circumferential direction of the blade ring 144. Each of the second
blades 146 extends curvedly from the inner edge of the blade ring
144 to the outer edge of the blade ring 144. Each of the outer
portions 147 of the first blades 142 extends curvedly from the
inner edge of the blade ring 144 to the outer edge of the blade
ring 144. Preferably, the second blades 146 and the outer portions
147 of the first blades 142 extend curvedly such that each second
blade 146 and a corresponding adjacent outer portion 147 of the
first blade 142 are oriented generally symmetrically opposite each
other. That is, in the present embodiment, the outer portions 147
of the first blades 142 extend outwards generally (slightly) toward
a rotation direction of the impeller 14, and the second blades 146
extend outwards generally (slightly) away from the rotation
direction of the impeller 14.
[0016] In this exemplary embodiment, the centrifugal fan rotates
clockwise. In this example, the inner portions 145 of the first
blades 142 are substantially or entirely straight, and extend
aslant from the annular wall 143 generally (slightly) toward a
counterclockwise direction; while the outer portions 147 of the
first blades 142 are arc-shaped, and extend generally (slightly)
toward a clockwise direction. Thus an area of each first blade 142
is enlarged, and more air can be driven by the first blades 142.
The second blades 146 are arc-shaped, and extend generally
(slightly) toward the counterclockwise direction. Considered
another way, each second blade 146 and the outer portion 147 of one
neighboring first blade 142 form a profile like a pair of
parentheses.
[0017] Referring to FIG. 1 again, when assembled, the impeller 14
is sandwiched between the top cover 120 and the bottom cover 122,
and surrounded by the sidewall 124 of the housing 12. The blade
ring 144, the second blades 146 and the outer portions 147 of the
first blades 142 all are located just under the top cover 120 of
the housing 12, while the inner portions 145 of the first blades
142 are aligned with the first air inlet 121 and second air inlet
123. A flow channel (not shown) is defined between the sidewall 124
of the housing 12 and the outmost edges of the first blades 142 and
second blades 146.
[0018] During operation, the impeller 14 is driven by a stator (not
shown) of the centrifugal fan 10 to be rotatable with respect to
the stator in the housing 12. As the impeller 14 rotates, the first
blades 142 force the air adjacent to the first air inlet 121 and
second air inlet 123 into the housing 12. The air then flows along
the flow channel to the air outlet 131 to generate high-pressure
airflow to the electronic component which needs to be cooled. Since
the outer portions 147 of the first blades 142 are curved to
enlarge the area of the first blades 142, an amount of the airflow
driven by the first blades 142 is improved. Further, the second
blades 146 arranged opposite to the first blades 142 can force the
airflow to flow radially to the air outlet 131, to thereby reduce
separation of the airflow at the outer edges of the first blades
142. Accordingly, air turbulence can be reduced, which not only
reduces energy loss of the airflow, but also reduces air noise of
the centrifugal fan 10. As a result, a greater amount of airflow
with reduced noise, and increased speed and pressure, is generated.
Thus, the heat dissipation efficiency and inconspicuousness of the
centrifugal fan 10 are improved.
[0019] It is to be understood, however, that even though numerous
characteristics and advantages of certain 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 disclosure to the full extent indicated by the
broad general meaning of the terms in which the appended claims are
expressed.
* * * * *