U.S. patent application number 10/139504 was filed with the patent office on 2004-03-11 for bi-directional incoming air flow fan.
Invention is credited to Lee, Bill.
Application Number | 20040047730 10/139504 |
Document ID | / |
Family ID | 31975745 |
Filed Date | 2004-03-11 |
United States Patent
Application |
20040047730 |
Kind Code |
A1 |
Lee, Bill |
March 11, 2004 |
BI-DIRECTIONAL INCOMING AIR FLOW FAN
Abstract
A bi-directional incoming air flow fan comprises a case in which
is mounted a rotor that includes a plurality of rotary blades. The
case has top and bottom faces that are respectively provided with a
first and second air inlet having approximately a same surface
area. A side of the case is further provided with an air outlet.
Furthermore, each rotary blade includes upper and lower sides that
respectively have an axial flow guiding rib, and a free section
that is inclined to form a radial flow section. Thereby, once the
rotor (40) is put in rotation, air flow amount and pressure are
increased by means of the axial flow guiding ribs (61) that create
an uniform air flow. As a result, rotor deviation and floating
force are reduced, thereby reducing mechanical frictions and
parasitic noise.
Inventors: |
Lee, Bill; (Chu-Pei City,
TW) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Family ID: |
31975745 |
Appl. No.: |
10/139504 |
Filed: |
May 7, 2002 |
Current U.S.
Class: |
415/220 |
Current CPC
Class: |
F04D 25/06 20130101;
F04D 29/281 20130101 |
Class at
Publication: |
415/220 |
International
Class: |
F01D 003/02 |
Claims
What is claimed is:
1. A bi-directional incoming air flow fan, comprising: a case,
having a top face and a bottom face respectively provided with
first and second air inlets of about the same surface area, a side
of the case being further provided with an air outlet; and a rotor,
mounted within the case, including a plurality of rotary blades,
each rotary blade including upper and lower sides respectively
provided with an axial flow guiding rib, and a free section that is
inclined in a manner to form a radial flow section; thereby the
axial flow guiding ribs uniformly guide air flow to increase air
flow amount and air flow pressure while reducing a deviation and a
floating force to which the rotor is subjected, thereby reducing
mechanical friction and parasitic noise.
2. The fan of claim 1, wherein the first and second air inlets are
respectively formed on lower and upper covers that assemble to each
other to form the case.
3. The fan of claim 2, wherein the upper and lower covers are
respectively provided with connecting portions and connecting slots
that assemble with one another.
4. The fan of claim 1, wherein the rotor includes a central pivot
head that is provided with a recess to mount a driving unit
therein.
5. The fan of claim 2, wherein a side of the lower cover is further
provided with a slot into which electrical wires of the driving
unit are received.
6. The fan of claim 1, wherein each rotary blade is inclined
forward of 30.degree.-120.degree. and extends outward, while having
a surface area that progressively increases from the inward to the
outward to form one axial flow guiding rib, the free section of
each rotary blade being further inclined forward
15.degree.-60.degree. to form one radial flow section that guides
outgoing air flow.
Description
FIELD OF THE INVENTION
[0001] The invention relates to a bi-directional incoming air flow
fan and, more particularly, a bi-directional incoming air flow fan
used in a computer assembly to dissipate heat.
BACKGROUND OF THE INVENTION
[0002] Electrical fans are usually used to create an air flow and
commonly provide the possibility of changing the outputted air flow
direction. Electrical fans can be differentiated from their
directions of air flow input and output. Such a differentiation
principally leads to a distinction between axial flow type fans and
centrifuge type fans. Axial flow type fans have the characteristics
of generating an incoming air flow from the rotation axis of the
rotary blades, the air flow then is compressed and outputted along
the same rotation direction. In contrast, centrifuge type fans
generate an axial incoming air flow that is outputted along the
radial direction of the rotary blades.
[0003] Centrifuge type fans are traditionally known as blowers, and
are usually comprised of a case and a rotor mounted in the case. It
is further common that the case includes an axial face that has an
air inlet and a radial face that has an air outlet. The rotor
includes a plurality of rotary blades that, once put in rotation,
generate an incoming air flow from the air inlet axially disposed,
and an outgoing air flow through the air outlet.
[0004] Because a single face of the above traditional fan is
provided with an air inlet, higher air flow amount therefore cannot
provided. The prior art thus also provides a centrifuge type fan
having a bi-directional incoming air flow. In this type of known
fan, two axial faces of the case are respectively provided with an
air inlet. However, because the air inlets do not have an equal
surface area, incoming air flows are therefore not symmetrical when
the rotor rotates, which causes deviation and generation of a
floating force or compressive force to which the rotor is
negatively subjected to. This results in an increase of friction
and vibration of the rotor, which affects the life service of the
fan and further generates parasitic noise.
SUMMARY OF THE INVENTION
[0005] It is therefore a principal object of the invention to
provide a centrifuge type fan with bi-directional incoming air flow
that can achieve a uniform incoming air flow from two sides,
thereby reducing a deviation of the rotor and mechanical frictions
due to a floating force, while providing a higher amount of air
flow output.
[0006] To accomplish the above and other objectives, a
bi-directional incoming air flow fan of the invention comprises a
case in which is mounted a rotor that includes a plurality of
rotary blades. The case has top and bottom faces that are
respectively provided with a first and second air inlet having
approximately a same surface area. A side of the case is further
provided with an air outlet. Furthermore, each rotary blade
includes an upper and lower sides that respectively have an axial
flow guiding rib, and a free section that is inclined to form a
radial flow section. Thereby, once the rotor is put in rotation,
air flow amount and pressure are increased by means of the axial
flow guiding ribs that create an uniform air flow. As a result,
rotor deviation and floating force are reduced, thereby reducing
mechanical frictions and parasitic noise.
[0007] To provide a further understanding of the invention, the
following detailed description illustrates embodiments and examples
of the invention, this detailed description being provided only for
illustration of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The drawings included herein provide a further understanding
of the invention. A brief introduction of the drawings is as
follows:
[0009] FIG. 1 is an external perspective view illustrating a
bi-directional incoming air flow fan according to an embodiment of
the invention;
[0010] FIG. 2 is an exploded view illustrating the fan according to
an embodiment of the invention;
[0011] FIG. 3 is a perspective view of the lower cover of the
invention; and
[0012] FIG. 4 is a partial section view of the rotor of the
invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0013] Wherever possible in the following description, like
reference numerals will refer to like elements and parts unless
otherwise illustrated.
[0014] Referring to FIG. 1, an external perspective view
schematically illustrates a fan with bi-directional incoming air
flow according to an embodiment of the invention. As shown in FIG.
1, the fan comprises a case 10 in which is assembled a rotor
40.
[0015] FIG. 2 is an exploded view of the fan according to an
embodiment of the invention. As illustrated, the case 10 is
comprised of lower and upper covers 20, 30 assembled with each
other. On axial faces corresponding to the rotation axis of the
rotor 40, the lower and upper covers 20, 30 are respectively
provided with first and second air inlets 21, 31 of about a same
surface area. On a side of the lower cover 20 is further arranged
an air outlet 34. Meanwhile, a slot 32 (better seen in FIG. 3) is
arranged on another side of the lower case 20 corresponding to the
periphery of the second air inlet 31. With further reference to
FIG. 4, the rotor 40 is comprised of a central pivot head 50 at a
periphery of which are disposed a plurality of rotary blades 60.
The pivot head 50 is further provided with a recess 51 that is
arranged in a manner to receive a driving unit (not shown), the
connection wires of the driving unit can be received in the slot
32.
[0016] Each rotary blade 60 is oriented forward of an inclination
angle of 30.degree.-120.degree. and radially extends outward, with
a surface area progressively increasing from the interior (head 50
side) to the exterior. Axial flow guiding ribs 61 are respectively
arranged on upper and lower sides of each blade 60 to axially guide
incoming air flow. A free section of each blade 60 is further
forward inclined 15.degree.-60.degree. to form a radial flow
section 62 through which air flow is radially guided outward. By
means of the axial flow guiding ribs 61 that uniformly guide air
flows, the air flow amount and air flow pressure are increased
while the deviation and floating force to which the rotor 40 is
usually subjected are reduced, mechanical frictions and parasitic
noise are therefore favorably reduced.
[0017] The lower and upper covers 20, 30 are provided with
connecting portions/slots 22, 33 that assemble with one another
once the rotor 40 is mounted.
[0018] In use, the rotor rotates under the drive of the driving
unit (not shown). The rotation of the rotary blades 60 drives air
flow to axially penetrate the case 10 by means of the axial flow
guiding ribs 61. Due to an identical section of the first and
second air inlets 21, 31 and a similar direction of the axial flow
guiding ribs 61 of the rotary blades 60, incoming air flow can be
therefore uniformly guided from the two sides of the case 10. Via
this balanced incoming air flow, the deviation, floating force, and
compressive force to which the rotor 40 is usually subjected to due
to air flow circulation are favorably reduced, meanwhile the air
flow amount and air flow pressure are increased. Furthermore, the
friction between the bearings and other different elements of the
fan (not shown) is also reduced, which results in noise reduction
and extends the service life of the elements of the fan. Air flow
entering the case 10 is oriented toward the air outlet 34 by means
of the radial flow sections 62 of the rotary blades 60. Thereby, a
revolution cycle can achieve an air flow that incomes from two
sides and radially outgoes.
[0019] Because the fan of the invention can achieve a
bi-directional incoming air flow, the amount of air flow outputted
by the fan of the invention is relatively greater than traditional
fans having a same volume. Within electric appliances having small
placement space while requiring a relatively high thermal
dissipation such as computer assemblies, the fan of the invention
is therefore particularly advantageous because it allows either a
better thermal dissipation for a same fan volume, or a reduced size
for equal performance of thermal dissipation, thereby allowing
releasing more space. Moreover, by achieving a bi-directional
incoming air flow, the invention can reduce the rocking of the
rotor 40 in rotation, thereby reducing negative friction and
parasitic noise and extending the life span of the fan.
[0020] It should be apparent to those skilled in the art that the
above description is only illustrative of specific embodiments and
examples of the invention. The invention should therefore cover
various modifications and variations made to the herein-described
structure and operations of the invention, provided they fall
within the scope of the invention as defined in the following
appended claims.
* * * * *