U.S. patent application number 11/376094 was filed with the patent office on 2007-05-17 for centrifugal fan and impeller thereof.
This patent application is currently assigned to DELTA ELECTRONICS, INC.. Invention is credited to Huan-Chi Chen, Wen-Shi Huang, Chung-Kai Lan.
Application Number | 20070110572 11/376094 |
Document ID | / |
Family ID | 38040995 |
Filed Date | 2007-05-17 |
United States Patent
Application |
20070110572 |
Kind Code |
A1 |
Lan; Chung-Kai ; et
al. |
May 17, 2007 |
Centrifugal fan and impeller thereof
Abstract
An impeller applied to a centrifugal fan includes a base plate,
a hub and a plurality of blades. The hub is connected to the base
plate. The blades are disposed around the base plate and around the
hub. The blades are the backward leaning structures and each blade
has at least one inversely inflective portion located at its tail.
A centrifugal fan including the impeller is also disclosed.
Inventors: |
Lan; Chung-Kai; (Taoyuan
Hsien, TW) ; Chen; Huan-Chi; (Taoyuan Hsien, TW)
; Huang; Wen-Shi; (Taoyuan Hsien, TW) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Assignee: |
DELTA ELECTRONICS, INC.
|
Family ID: |
38040995 |
Appl. No.: |
11/376094 |
Filed: |
March 16, 2006 |
Current U.S.
Class: |
415/203 |
Current CPC
Class: |
F04D 29/281 20130101;
F05D 2240/304 20130101; F04D 29/30 20130101; F04D 25/0606
20130101 |
Class at
Publication: |
415/203 |
International
Class: |
F01D 1/02 20060101
F01D001/02 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 11, 2005 |
TW |
094139631 |
Claims
1. An impeller comprising: a base plate; a hub connected to the
base plate; and a plurality of blades disposed on the base plate
and around the hub, wherein each of the blades has at least one
inversely inflective portion located at a tail of the blade.
2. The impeller of claim 1, wherein the base plate, the hub and the
blades are integrally formed as a single unit.
3. The impeller of claim 1, wherein the inversely inflective
portion has a smooth surface.
4. The impeller of claim 1, wherein the base plate is
ring-shaped.
5. The impeller of claim 1, further comprising: a connecting ring
connected to a side of the blades opposite to another side of the
blades facing the base plate.
6. The impeller of claim 5, wherein the connecting ring and the
blades are integrally formed.
7. The impeller of claim 1, wherein the blades are backward leaning
structures or curved structures.
8. A centrifugal fan comprising: an impeller comprising a base
plate, a hub, and a plurality of blades, wherein the hub is
connected to the base plate, and the blades are disposed on the
base plate and around the hub; and a motor coupled to the impeller
for driving the impeller to rotate, wherein each of the blades has
at least one inversely inflective portion located at a tail of the
blade.
9. The centrifugal fan of claim 8, wherein the base plate, the hub
and the blades are integrally formed as a single unit.
10. The centrifugal fan of claim 8, wherein the inversely
inflective portion has a smooth surface.
11. The centrifugal fan of claim 8, wherein the base plate is
ring-shaped.
12. The centrifugal fan of claim 8, wherein the motor is
accommodated in the hub.
13. The centrifugal fan of claim 8, further comprising: a
connecting ring connected to a side of the blades opposite to
another side of the blades facing the base plate.
14. The centrifugal fan of claim 13, wherein the connecting ring
and the blades are integrally formed.
15. The centrifugal fan of claim 8, wherein the blades are backward
leaning structures or curved structures.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of Invention
[0002] The invention relates to a fan and, in particular, to a
centrifugal fan.
[0003] 2. Related Art
[0004] Since the present electronic products are rapidly developed
towards the goals of high performance, high frequency, high speed
and compactness, the generated heat of the electronic products
becomes greater. However, the electronic products may be unstable
in the high temperature, which results in the poor reliability
thereof. Thus, the heat dissipation has become an important issue
of the present electronic products.
[0005] The fan is commonly used as a heat dissipating device for
the electronic product. FIG. 1a and FIG. 1b are top views of two
kinds of conventional centrifugal fans 1 and 1', both of which have
a plurality of blades. Based on the arrangement, the blades may be
forward leaning blades 11 (shown in FIG. 1a) or backward leaning
blades 11' (shown in FIG. 1b). The rotation directions of the
blades are shown by the arrows in FIGS. 1a and 1b. Under the same
rotation speed, the forward leaning blades 11 can output higher air
pressure for providing better heat dissipation effect. However, the
loading of the motor increases, and the power consumption is
higher. Contrariwise, the backward leaning blades 11' provide a
heat dissipation effect not as good as that provided by the forward
leaning blades 11, but the power consumption of the backward
leaning blades 11' is lower. Therefore, the manufacturer can choose
different types of the blades according to the actual needs of
power consumption.
[0006] As shown in FIG. 2, a conventional centrifugal fan 2
includes an impeller 21 and a motor 22. The impeller 21 includes a
base plate 213, a hub 211, and a plurality of backward leaning
blades 212. The base plate 211 is connected to the hub 211, and the
blades 212 are disposed on the base plate 211 and around the hub
211. The impeller 21 further includes a connecting ring 214, which
is connected to a side of the blades 212 opposite to another side
thereof facing the base plate 213. The motor 22 is accommodated in
the hub 211 for driving the impeller 21 to rotate.
[0007] When the impeller, 21 rotates, airflow enters. the center of
the impeller 21. Then, the blades 212 force the airflow to
radiately flow out of the blades 212. Since the air pressure
provided by the backward leaning blades is smaller than that of the
forward leaning blades, the fan 2 utilizing the backward leaning
blades provides inferior heat dissipation effect.
[0008] It is therefore an important subject of the invention to
improve the heat dissipation efficiency of the backward leaning
blades with lower power consumption.
SUMMARY OF THE INVENTION
[0009] In view of the foregoing, the invention is to provide a
centrifugal fan and an impeller thereof that can improve the
efficiency thereof for enhancing the heat dissipation effect with
lower power consumption.
[0010] To achieve the above, an impeller of the invention includes
a base plate, a hub, and a plurality of blades. The hub is
connected to the base plate. The blades are disposed on the base
plate and around the hub. In the invention, the blades are backward
leaning structures and each blade has at least one inversely
inflective portion located at a tail of the blade.
[0011] To achieve the above, a centrifugal fan of the invention
includes an impeller and a motor accommodated underneath the
impeller. The impeller includes a base plate, a hub, and a
plurality of blades. The hub is connected to the base plate. The
blades are disposed on the base plate and around the hub. In the
invention, the blades are backward leaning structures and each
blade has at least one inversely inflective portion located at a
tail of the blade.
[0012] As mentioned above, the centrifugal fan and impeller of the
invention have the blades of the backward leaning structures, each
of which has at least one inversely inflective portion located at a
tail of the blade. Thus, when the airflow flows through the tails
of the blades, the inversely inflective portion is capable of
increasing the airflow quantity of the fan. As a result, the
efficiency of the fan can be efficiently improved for enhancing the
heat dissipation effect with lower power consumption.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The invention will become more fully understood from the
detailed description given herein below illustration only, and thus
is not limitative of the present invention, and wherein:
[0014] FIG. 1a is a top view of a conventional centrifugal fan that
has forward leaning blades;
[0015] FIG. 1b is a top view of a conventional centrifugal fan that
has backward leaning blades;
[0016] FIG. 2 is a schematic view of a conventional centrifugal
fan;
[0017] FIG. 3a is a top view of a centrifugal fan and an impeller
thereof according to a preferred embodiment of the invention;
[0018] FIG. 3b is an enlarged diagram showing an inversely
inflective portion shown in FIG. 3a;
[0019] FIG. 4 is a three dimensional view of the centrifugal fan
according to the preferred embodiment of the invention; and
[0020] FIG. 5 is a schematic diagram showing efficiency curves of
the conventional centrifugal fan and the centrifugal fan of the
present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0021] The present invention will be apparent from the following
detailed description, which proceeds with reference to the
accompanying drawings, wherein the same references relate to the
same elements.
[0022] FIG. 3a is a top view of a centrifugal fan and an impeller
thereof according to a preferred embodiment of the invention, and
FIG. 4 is a three dimensional view of the centrifugal fan and the
impeller. The centrifugal fan 3 includes an impeller 31 and a motor
32. The impeller 31 includes a base plate 312, a hub 311, and a
plurality of blades 313. The motor 32 is accommodated in the hub
311 for coupling to the impeller 31 and driving it to rotate. The
hub 311 is connected to the base plate 312. The blades 313 are
disposed on the base plate 312 and around the hub 311. In the
embodiment, the base plate 312 is ring-shaped, and the base plate
312, the hub 311 and the blades 313 are integrally formed as a
single unit. The blades 313 are backward leaning structures, and
each blade 313 has an inversely inflective portion 3131 located at
a tail of the blade 313. FIG. 3b is an enlarged diagram showing the
inversely inflective portion 3131. The inversely inflective portion
3131 has a smooth surface and is used to increase the airflow
quantity and efficiency of the impeller 31. In practice, the
present invention may provide several inversely inflective portions
at the tail of each blade according to the actual needs.
[0023] The impeller 31 further includes a connecting ring 314,
which is connected to a side of the blades 313 opposite to another
side thereof facing the base plate 312. Similarly, the connecting
ring 314 and the blades 313 may be integrally formed.
[0024] With reference to FIG. 5, an experimental analysis is
obtained by comparing the conventional centrifugal fan and the
centrifugal fan of the present invention. Herein, the X axis
represents the airflow quantity, and the Y axis represents the air
pressure. Under the same rotation speed of 4060 RPM, the
centrifugal fan of the invention can provide better efficiency than
the conventional one according to the efficiency curve of the
experimental analysis.
[0025] In summary, the centrifugal fan and impeller of the
invention have the blades of the backward leaning structures, each
of which has at least one inversely inflective portion located at a
tail of the blade. Thus, when the airflow flows through the tails
of the blades, the inversely inflective portion is capable of
increasing the airflow quantity of the fan. As a result, the
efficiency of the fan can be efficiently improved for enhancing the
heat dissipation effect with lower power consumption.
[0026] Although the invention has been described with reference to
specific embodiments, this description is not meant to be construed
in a limiting sense. Various modifications of the disclosed
embodiments, as well as alternative embodiments, will be apparent
to persons skilled in the art. It is, therefore, contemplated that
the appended claims will cover all modifications that fall within
the true scope of the invention.
* * * * *