U.S. patent application number 11/230450 was filed with the patent office on 2006-11-16 for heat dissipation apparatus and fan frame thereof.
This patent application is currently assigned to DELTA ELECTRONICS, INC.. Invention is credited to Hao-Ming Chen, Shih-Hua Ho, Wen-Shi Huang, Tsung-Yu Lei.
Application Number | 20060257254 11/230450 |
Document ID | / |
Family ID | 37311224 |
Filed Date | 2006-11-16 |
United States Patent
Application |
20060257254 |
Kind Code |
A1 |
Ho; Shih-Hua ; et
al. |
November 16, 2006 |
Heat dissipation apparatus and fan frame thereof
Abstract
A heat dissipation apparatus. A fan frame accommodates an
impeller therein and includes an air inlet, an air outlet, and a
passage for guiding airflow from the air inlet to the air outlet.
An inner peripheral wall of the passage radially and outwardly
extends a smooth curved expansion portion at the air outlet. The
curved expansion portion includes a recess in which the airflow
forms an airflow layer, stopping subsequent airflow from directly
contacting the inner peripheral wall of the passage.
Inventors: |
Ho; Shih-Hua; (Taoyuan
Hsien, TW) ; Chen; Hao-Ming; (Taoyuan Hsien, TW)
; Lei; Tsung-Yu; (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: |
37311224 |
Appl. No.: |
11/230450 |
Filed: |
September 21, 2005 |
Current U.S.
Class: |
415/220 |
Current CPC
Class: |
F04D 29/545 20130101;
F04D 29/667 20130101; F04D 25/0613 20130101 |
Class at
Publication: |
415/220 |
International
Class: |
F04D 19/00 20060101
F04D019/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 13, 2005 |
TW |
94115554 |
Claims
1. A fan frame for a heat dissipation apparatus, comprising: a
casing comprising a passage for guiding airflow from one opening to
another opening, wherein the casing further comprises a smooth
curved expansion portion being radially and outwardly extended from
an inner peripheral wall of the passage at either one or both
openings.
2. The fan frame as claimed in claim 1, wherein the curved
expansion portion further comprises a recess in which the airflow
forms an airflow layer, stopping subsequent airflow from directly
contacting the inner peripheral wall of the passage.
3. The fan frame as claimed in claim 1, wherein the openings are an
air inlet and an air outlet, and the smooth curved expansion
portion is radially and outwardly extended from the inner
peripheral wall of the passage at the air outlet.
4. The fan frame as claimed in claim 3, wherein the curved
expansion portion at the air outlet is radially and outwardly
extended out of the casing and is symmetrical with respect to an
axis of the passage.
5. The fan frame as claimed in claim 3, wherein the curved
expansion portion at the air outlet has a tapered angle, a bevel
angle, a tapered bevel angle, or a large R angle.
6. The fan frame as claimed in claim 3, wherein the casing further
comprises another smooth curved expansion portion, being radially
and outwardly extended from the inner peripheral wall of the
passage at the air inlet, which is symmetrical with respect to an
axis of the passage.
7. The fan frame as claimed in claim 3, wherein the smooth curved
expansion portion is radially and outwardly extended out of the
casing from the inner peripheral wall of the passage at the air
inlet and is symmetrical with respect to an axis of the
passage.
8. The fan frame as claimed in claim 3, wherein the smooth curved
expansion portion is radially and outwardly extended from the inner
peripheral wall of the passage at the air inlet in a circular or
elliptical shape with respect to an axis of the passage.
9. The fan frame as claimed in claim 3, wherein the inner
peripheral wall of the passage at the air inlet has a tapered
angle, a bevel angle, a tapered bevel angle, or a large R angle and
is symmetrical with respect to an axis of the passage.
10. A heat dissipation apparatus, comprising: an impeller; and a
fan frame for accommodating the impeller therein and comprising a
passage for guiding airflow from one opening to another opening,
wherein the fan frame further comprises a smooth curved expansion
portion being radially and outwardly extended from an inner
peripheral wall of the passage at either one or both openings.
11. The heat dissipation apparatus as claimed in claim 10, wherein
the curved expansion portion further comprises a recess in which
the airflow forms an airflow layer, stopping subsequent airflow
from directly contacting the inner peripheral wall of the
passage.
12. The heat dissipation apparatus as claimed in claim 10, wherein
the openings are an air inlet and an air outlet, and the smooth
curved expansion portion is radially and outwardly extended from
the inner peripheral wall of the passage at the air outlet.
13. The heat dissipation apparatus as claimed in claim 10, wherein
the length of blades of the impeller is increased corresponding to
the radially and outwardly extended curved expansion portion.
14. The heat dissipation apparatus as claimed in claim 10, wherein
the heat dissipation apparatus is an axial flow fan.
15. The heat dissipation apparatus as claimed in claim 10, further
comprising a motor base disposed in the fan frame, wherein the
impeller is disposed on the motor base, and the motor base
comprises a slope inclined radially, thereby increasing areas of
air flow intake or discharge.
16. The heat dissipation apparatus as claimed in claim 15, wherein
the slope is flat or curved.
17. A heat dissipation system, comprising: a system housing; at
least one electronic device, disposed in the system housing; and a
heat dissipation apparatus applied to the system housing for
dissipating heat generated by the electronic device, wherein the
heat dissipation apparatus comprises an impeller and a fan frame
for accommodating the impeller therein, the fan frame comprises a
passage for guiding airflow from one opening to another opening,
and the fan frame further comprises a smooth curved expansion
portion being radially and outwardly extended from an inner
peripheral wall of the passage at either one or both openings.
18. The heat dissipation system as claimed in claim 17, wherein the
curved expansion portion further comprises a recess in which the
airflow forms an airflow layer, stopping subsequent airflow from
directly contacting the inner peripheral wall of the passage.
19. The heat dissipation system as claimed in claim 17, wherein the
openings are an air inlet and an air outlet, and the casing further
comprises a smooth curved expansion portion being radially and
outwardly extended from the inner peripheral wall of the passage at
the air outlet.
20. The heat dissipation system as claimed in claim 19, wherein the
curved expansion portion at the air outlet has a tapered angle, a
bevel angle, a tapered bevel angle, or a large R angle.
Description
BACKGROUND
[0001] The invention relates to a heat dissipation apparatus and a
fan frame thereof, and in particular to a fan and a fan frame
providing reduced noise.
[0002] As performance of electronic devices is promoted, heat
dissipation apparatuses or systems are indispensable and thus used
in the electronic devices. If heat generated by an electronic
device is not efficiently dissipated, performance of the electronic
device may deteriorate or the electronic device may be damaged.
[0003] Fans serve widely as heat dissipation apparatuses. FIG. 1A
is a schematic view of a conventional fan 1, and FIG. 1B is a
schematic cross section taken along A-A' of FIG. 1A. The
conventional fan 1 is composed of a fan frame 11 and an impeller
12. When the fan 1 operates, the impeller 12 is activated by a
motor 13, providing airflow to a heat source (such as a
heat-generating electronic device, not shown) and thus dissipating
heat therefrom. The fan frame 11 has a through hole forming an air
inlet 112 and an air outlet 114 on two ends of the fan frame 11,
respectively. The air inlet 112 is connected to the air outlet 114
by way of a central passage 116, such that the airflow provided by
the impeller 12 can freely pass the air inlet 112 and air outlet
114. Additionally, four threaded holes 14 are formed on the corners
of the fan frame 11, by means of which the fan 1 can be fixed to
the shell of a system having electronic devices, such as a
computer.
[0004] FIGS. 1C, 1E, and 1F are schematic cross sections of
conventional fans and fan frames. A bevel angle C (as shown in FIG.
1C) or a tapered angle D (as shown in FIG. 1E) is formed near the
air inlet 112 or air outlet 114 of the fan frame 11 in order to
increase the area through which the airflow passes. As shown in
FIG. 1D, although the bevel angle C increases the area of the air
outlet 114, output airflow cannot be concentrated, thus reducing
the airflow pressure provided by the fan frame 11. Alternatively, a
recessed opening E (as shown in FIG. 1F) is formed near the air
outlet 114 of the fan frame 11 by cutting parts of entirety of the
fan frame, which is in order to increase the area through which the
airflow passes. However, the airflow is easily dispersed from the
recessed opening E.
[0005] Conventionally, when airflow passes through the air outlet
114, the airflow directly contacts the periphery of the inner wall
of the central passage 116 (as shown in FIG. 1B), bevel angle C,
tapered angle D, or wall of the recessed opening E. Accordingly,
the airflow can not pass through the air outlet 114 smoothly and is
slowed. Also, noise is generated by friction between airflow and
the inner peripheral wall of the central passage 116. Specifically,
the higher the rotational speed of the fan, the more the noise
generated thereby.
SUMMARY
[0006] Hence, the invention provides a heat dissipation apparatus
(a fan) and a frame thereof. The fan and fan frame has a smooth
curved expansion portion capable of reducing noise generated by
friction between airflow and the inner peripheral wall of the
passage, stabilizing and concentrating the airflow, and enhancing
performance of the fan. Moreover, the inner peripheral wall of the
fan frame outwardly extends, increasing areas of air flow intake or
discharge, concentrating the airflow, and enhancing performance of
the fan. Further, the fan is easily applied to a heat dissipation
system or any other electronic devices which generate heat by
assembling without modifying arrangement of the system.
[0007] An embodiment of the invention provides a fan frame for a
heat dissipation apparatus. The fan frame comprises a casing having
a passage for guiding airflow from one opening to another opening.
An inner peripheral wall of the passage radially and outwardly
extends a smooth curved expansion portion at either one or both
openings. The curved expansion portion further comprises a recess
in which the airflow forms an airflow layer, stopping subsequent
airflow from directly contacting the inner peripheral wall of the
passage. The curved expansion portion is radially and outwardly
extended out of the casing and is symmetrical with respect to an
axis of the passage. Further, the curved expansion portion at
either one or both openings has a tapered angle, a bevel angle, a
tapered bevel angle, or a large R angle.
[0008] An inner peripheral wall of the passage radially and
outwardly extends at the air inlet and is symmetrical with respect
to the axis of the passage. Alternatively, an inner peripheral wall
of the passage at the air inlet is radially and outwardly extended
out of the casing and is symmetrical with respect to the axis of
the passage. Alternatively, the inner peripheral wall of the
passage at the air inlet radially and outwardly extends out of the
casing in a circular or elliptical shape and is symmetrical with
respect to the axis of the passage. The inner peripheral wall of
the passage at the air inlet has a tapered angle, a bevel angle, a
tapered bevel angle, or a large R angle with respect to the axis of
the passage.
[0009] Another embodiment of the invention provides a heat
dissipation apparatus comprising an impeller and a fan frame. The
fan frame accommodates the impeller therein and comprises a passage
for guiding airflow from one opening to another opening. An inner
peripheral wall of the passage radially and outwardly extends a
smooth curved expansion portion at either one or both openings. The
curved expansion portion further comprises a recess in which the
airflow forms an airflow layer so as to stop subsequent airflow
from directly contacting the inner peripheral wall of the passage.
The curved expansion portion is symmetrical with respect to the
axis of the passage. Alternatively, the curved expansion portion is
radially and outwardly extended out of the fan frame and is
symmetrical with respect to the axis of the passage. The curved
expansion portion at least one of the openings has a tapered angle,
a bevel angle, a tapered bevel angle, or a large R angle.
[0010] The heat dissipation apparatus comprises an axial flow fan.
The length of blades of the impeller is increased corresponding to
the radially and outwardly extended curved expansion portion. The
heat dissipation apparatus further comprises a motor base disposed
in the fan frame. The impeller is disposed on the motor base. The
motor base comprises a slope inclined radially, thereby increasing
areas of air flow intake or discharge, and the slope is flat or
curved. The fan frame is substantially rectangular, circular,
elliptical, or rhomboid.
[0011] Still another embodiment of the invention provides a heat
dissipation system comprising a system housing, at least one
electronic device, and a heat dissipation apparatus. The electronic
device is disposed in the system housing. The heat dissipation
apparatus is applied to the system housing for dissipating heat
generated by the electronic device during operation. The heat
dissipation apparatus comprises an impeller and a fan frame
accommodating the impeller. The fan frame comprises a passage for
guiding airflow from one opening to another opening. An inner
peripheral wall of the passage radially and outwardly extends a
smooth curved expansion portion at either one or both openings.
DESCRIPTION OF THE DRAWINGS
[0012] The invention can be more fully understood by reading the
subsequent detailed description and examples with references made
to the accompanying drawings, wherein:
[0013] FIG. 1A is a schematic view of a conventional fan;
[0014] FIG. 1B is a schematic cross section taken along A-A' of
FIG. 1A;
[0015] FIGS. 1C, 1E, and 1F are schematic cross sections of
conventional fan frames;
[0016] FIG. 1D is a schematic view showing the direction of air
flow in the fan frame of FIG. 1C;
[0017] FIG. 2A is a schematic view of the fan of an embodiment of
the invention;
[0018] FIG. 2B is a schematic cross section taken along B-B' of
FIG. 2A;
[0019] FIG. 3A is a schematic view showing the curved expansion
portion F of FIG. 2B and the direction of air flow near the curved
expansion portion F;
[0020] FIG. 3B is a schematic cross section of another fan frame of
the invention;
[0021] FIG. 4 is a schematic view showing that the heat dissipation
apparatus of the invention is applied to a system having electronic
devices;
[0022] FIG. 5A and FIG. 5B are diagrams showing audio comparison of
the conventional and present fans;
[0023] FIG. 6A and FIG. 6B are diagrams showing volume comparison
of the conventional and present fans; and
[0024] FIG. 7 is a diagram showing characteristic comparison of the
conventional and present fans.
DETAILED DESCRIPTION
[0025] Referring both to FIG. 2A and FIG. 2B, the heat dissipation
apparatus 2 can be, for example, an axial flow fan and has a fan
frame 21, an impeller 22, and a motor base 26. The fan frame 21 may
be a substantially rectangular, circular, elliptical, or rhomboid
casing. The fan frame 21 has a through hole so as to form a passage
216 therein, an air inlet 212, and an air outlet 214. The air inlet
212 is connected to the air outlet 214 by way of the passage 216.
The passage 216 can guide airflow from one opening (air inlet 212)
to the other opening (air outlet 214). Airflow generated by the
impeller 22 can thus enter and leave the fan frame 21.
Additionally, multiple threaded holes 24 are formed on corners of
the fan frame 21 so that the fan 2 can be fixed to a housing of an
electronic system, such as a computer.
[0026] The fan frame 21 accommodates the impeller 22 therein, and
the motor base 26 is disposed in the fan frame 21. The impeller 22
is disposed on the motor base 26. When the fan 2 operates, a motor
23 disposed on the motor base 26 activates the impeller 22 so as to
provide airflow to an electronic device (not shown) and dissipating
the heat generated by the electronic device.
[0027] Referring to FIG. 2B and FIG. 3A, an inner peripheral wall
of the passage 216 radially and outwardly extends a smooth curved
expansion portion F at the air outlet 214. The curved expansion
portion F includes a recess 218 in which the airflow forms an
airflow layer so as to stop subsequent airflow from directly
contacting the inner peripheral wall of the passage 216.
Specifically, the airflow in the recess 218 provides an air
cushion, thereby stopping subsequent airflow from directly
contacting the frame wall of the fan frame 21. Accordingly,
friction between air and solid is changed to friction between air
to air, and noise is thus reduced. Moreover, the recess 218 of the
curved expansion portion F provides sufficient space for airflow,
whereby stabilizing the airflow. Additionally, when the airflow
passes through the air outlet 214, the curved expansion portion F
can sufficiently concentrate the airflow and enhance air pressure
compared to the conventional fan frame 11 (FIG. 1D).
[0028] The curved expansion portion F is symmetrical with respect
to the axis of the passage 216. Also, another curved expansion
portion is radially and outwardly extended from the inner
peripheral wall of the passage 216 at the air inlet 212. Moreover,
the length of blades of the impeller 22 matches the fan frame 21
and is increased corresponding to the radially and outwardly
extended curved expansion portion F so as to increase air volume.
Preferably, the curved expansion portion F at the air outlet 214
may be formed with a tapered angle 219a (FIG. 3A), a bevel angle, a
tapered bevel angle, or a large R angle, so as to allow the airflow
more smoothly passing through the fan frame 21.
[0029] Additionally, the inner peripheral wall of the fan frame 21
at the air inlet 212 may be formed with a bevel angle 219b (FIG.
2B), a tapered angle, a tapered bevel angle, or a large R angle,
increasing the area of the air inlet 212. Alternatively, the inner
peripheral wall of the passage 216 at the air inlet 212 is radially
and outwardly extended out of the fan frame 21 in a circular or
elliptical shape and is symmetrical with respect to the axis of the
passage 216.
[0030] Moreover, the curved expansion portion F may be radially and
outwardly extended out of the fan frame 21 with respect to the axis
of the passage 216 so as to increase the area through which the
airflow passes.
[0031] FIG. 3B shows another fan frame of an embodiment of the
invention. As the above mentioned, the present invention discloses
the curved expansion portion F with a tapered angle at the air
inlet 212 and/or air outlet 214, the motor base 26 may additionally
include a slope 262 inclined radially to increase areas of air flow
intake or discharge. The slope 262 is flat or curved.
[0032] In practical application, the heat dissipation apparatus 2
can be applied to a heat dissipation system 5 which includes a
system housing 3 and multiple electronic devices, as shown in FIG.
4. Inside of the system housing 3, the electronic devices or heat
sources are mostly on a circuit board 4, and the heat dissipation
apparatus 2 is disposed within a suitable position of the system
housing 3, such that cold airflow generated by the heat dissipation
apparatus 2 is provided during operation to the electronic devices
or heat sources. Accordingly, heat generated by the electronic
devices is efficiently dissipated, and the electronic devices are
thus prevented from damaging due to high temperature.
[0033] FIG. 5A is a diagram showing results of audio testing of a
conventional fan. FIG. 5B is a diagram showing results of audio
testing of the present fan. Both the conventional and present fans
have a diameter of approximate 8 cm and were tested at speed of
5700 rpm. Comparing the results shown in FIG. 5A and FIG. 5B, the
conventional fan incurs obvious noise at frequency of 665 Hz during
operation while the present fan did not.
[0034] FIG. 6A is a diagram showing results of volume testing of a
conventional fan. FIG. 6B is a diagram showing results of volume
testing of the present fan. Both the conventional and present fans
have a diameter of approximate 8 cm and were tested at speed of
5700 rpm. As shown in FIG. 6A, the noise value of the conventional
fan at speed of 5700 rpm was 49.6 dB. As shown in FIG. 6B, the
noise value of the present fan at the same speed was 46.7 dB.
Accordingly, the present fan can effectively reduce noise compared
to the conventional fan.
[0035] FIG. 7 is a diagram showing characteristic comparison of the
conventional and present fans. Both the conventional and present
fans have a diameter of approximate 8 cm and were tested at speed
of 5700 rpm. As shown in FIG. 7, the present fan provides larger
airflow pressure and volume compared to the conventional fan.
Specifically, at an airflow volume of 40 CFM, the conventional fan
provides an air pressure of 7.9 mmH.sub.2O while the present fan
provides an air pressure of 12.9 mmH.sub.2O. As the results, the
pressure provided by the present fan is increased by 63% compared
to the conventional fan. Alternatively, at an air pressure of 10
mmH.sub.2O, the conventional fan provides an airflow volume of 28.8
CFM while the present fan provides an airflow volume of 45 CFM. As
the results, the airflow volume provided by the present fan is
increased by 56% compared to the conventional fan. Accordingly, the
present fan effectively enhances the air pressure and volume and
thus rectifies the airflow.
[0036] In conclusion, the fans (heat dissipation apparatus) and fan
frame of the present invention provide curved expansion portions
capable of reducing noise from friction between airflow and the
frame wall, thereby stabilizing the airflow, and thus enhancing
performance of the fans. Moreover, without interfering with other
heat dissipation devices originally disposed in the fans, the inner
peripheral walls of the fan frames outwardly extend to increase the
area through which the airflow passes, thereby enhancing heat
dissipation of the fans. Further, the fan is easily applied to a
heat dissipation system or any other electronic devices which
generate heat by assembling without modifying arrangement of the
system.
[0037] While the invention has been described by way of example and
in terms of preferred embodiment, it is to be understood that the
invention is not limited thereto. To the contrary, it is intended
to cover various modifications and similar arrangements (as would
be apparent to those skilled in the art). Therefore, the scope of
the appended claims should be accorded the broadest interpretation
so as to encompass all such modifications and similar
arrangements.
* * * * *