U.S. patent application number 11/326363 was filed with the patent office on 2007-07-12 for centrifugal fan with low noise.
Invention is credited to Jun-Chien Yen.
Application Number | 20070160458 11/326363 |
Document ID | / |
Family ID | 38232885 |
Filed Date | 2007-07-12 |
United States Patent
Application |
20070160458 |
Kind Code |
A1 |
Yen; Jun-Chien |
July 12, 2007 |
Centrifugal fan with low noise
Abstract
A centrifugal fan with low noise includes a housing, a fan wheel
and a recess unit. The fan wheel has a hub and a plurality of fan
blade extending outward from the hub radially. The housing has a
chamber therein to receive the fan wheel and has a recess unit at
the surface thereof. The recess unit is composed of a projection
part and a recess part for reducing noise transmission greatly.
Inventors: |
Yen; Jun-Chien; (Taipei,
TW) |
Correspondence
Address: |
G. LINK CO. LTD.
3550 BELL ROAD
MINOOKA
IL
60447
US
|
Family ID: |
38232885 |
Appl. No.: |
11/326363 |
Filed: |
January 6, 2006 |
Current U.S.
Class: |
415/119 |
Current CPC
Class: |
F04D 29/663
20130101 |
Class at
Publication: |
415/119 |
International
Class: |
F04D 29/66 20060101
F04D029/66 |
Claims
1. A centrifugal fan with low noise, comprising: a housing,
providing a chamber therein; and a fan wheel, being received in the
chamber; characterized in that the housing has a recess unit at the
surface thereof for reducing noise.
2. The centrifugal fan with low noise as defined in claim 1,
wherein the recess unit is composed of at least a projection part
and a recess part.
3. The centrifugal fan with low noise as defined in claim 2,
wherein the projection part and the recess part is formed with a
grid shape.
4. The centrifugal fan with low noise as defined in claim 2,
wherein the projection part and the recess part is formed with a
parallel shape.
5. The centrifugal fan with low noise as defined in claim 1,
wherein the housing has at least an outlet communicating with the
chamber.
6. The centrifugal fan with low noise as defined in claim 1,
wherein the surface refers to the outer surface and/or the inner
surface of the housing.
7. The centrifugal fan with low noise as defined in claim 1,
wherein the fan wheel has a hub and a plurality of fan blades
extending outward from the hub radially.
8. The centrifugal fan with low noise as defined in claim 1,
wherein the housing is integrally made with the recess unit as a
single piece.
9. The centrifugal fan with low noise as defined in claim 1,
wherein the housing is made as an individual piece from the recess
unit.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention is related to a centrifugal fan with
low noise and particularly to a centrifugal fan capable of
attenuating noise.
[0003] 2. Brief Description of the Related Art
[0004] Application of the computer industry is getting popular
along with the information technology being highly developed.
Further, due to network being developed prosperously with a great
deal of network transmissions and data processing, more computer
equipment are needed for offering sufficient operation and
processing capability.
[0005] Owing to manufacturing process of integrated circuit being
improved, fabrication of integrated circuit is getting delicate and
complicated. Various computer equipments provide more powerful
functions. But, the complicated circuit leads to huge power
consumption and the power consumption results in a serious problem
because of temperature of the equipment rising caused by the power
consumption.
[0006] Generally speaking, fast transmission of heat is very
important for electronic equipment, especially which is a computer,
in order to obtain the greatest performance thereof. Because heat
congregating in the equipment and being incapable of being
dissipated outward properly, the electronic components inside are
unable to work normally and the entire equipment will be influenced
under this circumference. As a result, the computer system will be
shut down unexpectedly.
[0007] Hence, a heat dissipation device such as a cooling fan
usually is mounted in the electronic equipment for helping heat
dissipation from the electronic components. Ordinarily, the cooling
fan used in the electronic equipment is an axial flow fan or a
centrifugal fan. The centrifugal fan drags the air toward the
radial direction or toward a direction perpendicular to the shaft
of thereof.
[0008] When the fan wheel rotates, the air enters the centrifugal
fan via the center of the fan wheel and acquires energy by means of
centrifugal force of the air itself, the air, then, moves outward
radially along the fan blades. Thus, higher air pressure is created
so that the centrifugal fan is suitable for being applied in a
system, which has larger resistance. Further, flow field inside the
centrifugal fan is quite complicated and fluid flows radially along
with the fan wheel such that it produces phenomena such as
recirculation, reversed flow and separation to complicate flow
field in the fan wheel and produce high noise decibel.
[0009] Referring to FIGS. 1 to 3, the conventional centrifugal fan
includes a housing 11 and a fan wheel 13. The housing 11 has a
housing base 111 and a lid 112. The housing base 111 and the lid
member 112 provide a first inlet 111, a second inlet 1121 and an
outlet 12 respectively. The first inlet 1111 is attached with a
plurality of auxiliary ribs 1122. The fan wheel 13 is rotationally
mounted over the auxiliary ribs 1122 in the housing and includes a
hub 131 and a plurality of fan blades 132 extending outward from
the hub 131 radially.
[0010] When the fan wheel 13 rotates to actuate fluid entering the
housing 11 via the first inlet 1111 and the second inlet 1121, the
fluid then flows outward along the inner wall of the housing 11
toward the outlet 12.
[0011] However, a problem of the conventional centrifugal fan in
practice resides in that the housing 11 is flat at the surface
thereof with strengthen ribs 1122 being added at the reinforced
position only such that the fluid accelerates with increasing flow
energy after passing through the fan blades to impact the housing
11 while the fluid is entering the housing 11 via the first inlet
1111 and the second inlet 1121 and shooting outward speedily due to
the fan blades 132 rotating and it results in vibration and louder
noise because of the flat surface of the housing with too wick
structural tension.
[0012] In addition, rotational noise with various frequencies occur
during the fan is in operation and the noise with the frequencies
especially with the narrow band frequency easily transmits outward
to results in the user having uncomfortable feeling caused by the
narrow band noise being sharp to the hearing sense of the user.
SUMMARY OF THE INVENTION
[0013] A main object of the present invention is to provide a
centrifugal fan with low noise in which the housing has a recess
unit at the surface thereof to lessen transmission and creation of
noise.
[0014] Another object of the present invention is to provide a
centrifugal fan with low noise in which the recess unit on the
surface of the housing is formed with at least a projection part
and a recess part for intensifying strength of the surface of the
housing.
[0015] In order to achieve the preceding object, a centrifugal fan
with low noise according to the present invention includes a
housing and a fan wheel. The housing forms a chamber inside to
receive the fan wheel and has a recess unit at the surface thereof
to decrease noise being transmitted outward.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The detail structure, the applied principle, the function
and the effectiveness of the present invention can be more fully
understood with reference to the following description and
accompanying drawings, in which:
[0017] FIG. 1 is an exploded perspective view of the conventional
centrifugal fan;
[0018] FIG. 2 is a perspective view of the conventional centrifugal
fan shown in FIG. 1;
[0019] FIG. 3 is a sectional view of the conventional centrifugal
fan;
[0020] FIG. 4 is an exploded perspective view of the preferred
embodiment of a centrifugal fan with low noise according to the
present invention;
[0021] FIG. 5 is a perspective view of the preferred embodiment of
a centrifugal fan with low noise shown in FIG. 4;
[0022] FIG. 6 is a perspective view illustrating the lid member in
the preferred embodiment of a centrifugal fan according to the
present invention projecting from another direction;
[0023] FIG. 7 is a sectional view of the preferred embodiment of on
the centrifugal fan according to the present invention; and
[0024] FIG. 8 is a perspective view illustrating an alternative
configuration of the centrifugal fan according to the present
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0025] Referring to FIGS. 4 to 6, the preferred embodiment of a
centrifugal fan with low noise according to the present invention
includes a housing 21 and a fan wheel 22. The fan wheel 22 provides
a hub 221 and a plurality of fan blades 222 surrounding the hub 21
and extending outward radially from the hub 221. The housing 21 has
a housing base 211 and a lid member 212 and the housing base 211
has a bottom plate 2111 with a side plate 2112 extending along the
bottom plate 2111. A first inlet 2113 is provided at the bottom
plate 2111 and an outlet 2114 is provided at the side plate 2112. A
plurality of auxiliary ribs 2115 are arranged in the first inlet
2113 and a second inlet 2121 is provided at the lid member 212 to
define a chamber 23 with the bottom plate 2111 and the side plate
2112. The chamber 23 communicates with the outlet 2114.
[0026] Both the bottom plate 2111 and the lid member 212 of the
housing 21 provides at least a recess unit 24 at the surfaces
thereof and the recess unit 24 provides at least a projection part
241 and a recess part 242. The surfaces are the outer surfaces
and/or the inner surfaces and the projection part 241 and the
recess part 242 shown in the figures are formed with grid
shapes.
[0027] During being assembled, the fan wheel 22 is rotationally
mounted in the chamber 23 and the lid member 212 covers at a
lateral side opposite to the bottom plate 2111 and both the first
inlet 2113 and the outlet 2121 face the fan wheel 22.
[0028] Referring to FIG. 7, while the fan wheel 22 is running,
fluid enters the chamber 23 via the first inlet 2113 and the second
inlet 2121 respectively and is accelerated to shoot outward
radially after being actuated by the rotational fan wheel 22.
Afterward, the fluid flows toward the outlet 2114 along the inner
wall of the chamber 23. The projection part 241 and the recess part
242 of the recess unit 24 are capable of strengthening and
intensifying the surface structure of the housing 21 to resist
vibration during the accelerated fluid hitting inner part of the
housing 21 such that noise attenuates greatly. Further, it is able
to prevent from narrow frequency band noise created during the fan
wheel 22 running transmitting outward via the surface of the
housing 21 so that deficiency of noise transmitting outward via
flat surface of the housing is overcome.
[0029] In addition, the projection part and the recess part of the
recess unit can be formed with parallel shape as shown in FIG. 8
and the housing and the recess unit can be integrally made as a
single piece or can be made individual pieces.
[0030] While the invention has been described with referencing to
preferred embodiments thereof, it is to be understood that
modifications or variations may be easily made without departing
from the spirit of this invention, which is defined by the appended
claims.
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