U.S. patent application number 11/410972 was filed with the patent office on 2006-08-31 for fan enabling increased air volume.
This patent application is currently assigned to Asia Vital Components Co., Ltd.. Invention is credited to Wen-Hao Liu.
Application Number | 20060193723 11/410972 |
Document ID | / |
Family ID | 35460722 |
Filed Date | 2006-08-31 |
United States Patent
Application |
20060193723 |
Kind Code |
A1 |
Liu; Wen-Hao |
August 31, 2006 |
Fan enabling increased air volume
Abstract
A fan enabling increased air volume includes at least a fan
wheel and a driving unit for driving the fan wheel to maintain a
uniform rotating speed. The fan wheel includes a hub and a
plurality of blades radially extended from an outer periphery of
the hub. The blades may be arranged on the hub in different
manners, such as having a preceding blade overlapped a following
blade, or having a blade root installation angle smaller than
53.degree. and a blade tip inclination angle smaller than
46.degree., or having a solidity of blade roots larger than 1.5 and
a solidity of blade tips larger than 1, so that the fan wheel
produces increased air volume and accordingly enhanced cooling
power at the uniform rotating speed.
Inventors: |
Liu; Wen-Hao; (Hsin Chuang
City, TW) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Assignee: |
Asia Vital Components Co.,
Ltd.
Kaohsiung
TW
|
Family ID: |
35460722 |
Appl. No.: |
11/410972 |
Filed: |
April 26, 2006 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
10863337 |
Jun 9, 2004 |
|
|
|
11410972 |
Apr 26, 2006 |
|
|
|
Current U.S.
Class: |
415/220 |
Current CPC
Class: |
F04D 29/325
20130101 |
Class at
Publication: |
415/220 |
International
Class: |
F04D 19/00 20060101
F04D019/00 |
Claims
1. A fan enabling increased air volume, comprising: a fan wheel,
and a driving unit for driving said fan wheel to maintain a uniform
rotating speed; wherein said fan wheel includes: a hub, and a
plurality of blades radially extended from an outer periphery of
said hub; wherein a root of each of said a plurality of blades has
an installation angle smaller than 53.degree., and a tip of each of
said a plurality of blades has an inclination angle smaller than
46.degree., whereby said fan wheel produces increased air volume
and enhances cooling power at said uniform rotating speed.
2. The fan enabling increased air volume as claimed in claim 1,
wherein said driving unit includes a driving circuit board.
3. The fan enabling increased air volume as claimed in claim 1,
further comprising a housing in which said fan wheel and said
driving unit are mounted.
4. The fan enabling increased air volume as claimed in claim 1,
wherein said uniform rotating speed of said fan wheel has a
deviation within a range of .+-.8%.
Description
[0001] This application is a Divisional of co-pending application
Ser. No. 10/863,337, filed on Jun. 9, 2004, and for which priority
is claimed under 35 U.S.C. .sctn. 120, the entire contents of all
are hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a fan enabling increased
air volume, and more particularly to a fan with enhanced cooling
power.
BACKGROUND OF THE INVENTION
[0003] With the increasing developments in technological fields,
various kinds of electronic products are designed to provide more
functions so as to increase their value in use. The increased
functions necessitate the provision of more components or parts in
a system having a fixed volume. The large quantity of components or
parts in the electronic product result in reduced internal spaces
of the system while produce more heat in the limited internal
spaces of the system to necessitate the use of cooling means to
carry away the produced high amount of heat. A cooling fan is most
frequently selected to solve the problem of heat produced in the
system because it produces convective airflows to carry away the
produced heat from the system. However, when the airflows produced
by the cooling fan inward flow through the system, they are
inevitably impeded by the components or parts densely arranged in
the system to result in largely reduced cooling effect. Therefore,
it is necessary to increase the air volume and air pressure
produced by the cooling fan to maintain the expected cooling
effect. Currently, there are two ways to achieve this purpose. The
first way is to increase the rotating speed of the motor of the
fan, and the second way is to change the blade structure of the
fan. However, the increased motor rotating speed would result in
consumption of more power and accordingly waste of more energy.
[0004] FIG. 1 is a graph showing different fan characteristic
curves for a general fan used with a system having a relatively
small number of components or parts arranged therein. When the fan
is started to operate, airflows produced by the fan are interfered
in their flow paths by the components in the system. That is, the
impedance of the internal components of the system will prevent the
airflows produced by the fan from flowing smoothly to result in
loss of air pressure. In the graph of FIG. 1, the curve A1 is a
system impedance curve representing changes in the loss of air
volume produced by the fan, and will become lowered when the number
of components or parts in the system is low; the curve T is an air
volume curve representing the operating characteristic of the fan
measured in an air tunnel; the point P is an intersection of the
curve A1 with the curve T representing an operating point of the
system; and the circled area A surrounding the point P is an
operating range representing the operating performance of the fan
used with the system having lower number of internal
components.
[0005] Please refer to FIG. 2 that is a graph showing different fan
characteristic curves for a fan having overlapped blades and
operating at non-uniform rotating speeds for effectively solving
the problem of produced heat in a system having highly densely
arranged internal components or parts. When the overlapped blades
of the fan are rotated to produce airflows, the airflows are
interfered in their flow paths by the components in the system.
That is, the impedance of the internal components of the system
will prevent the airflows produced by the overlapped blades of the
fan from flowing smoothly to result in loss of air pressure. In the
graph of FIG. 2, the curve B1 is a system impedance curve
representing changes in the loss of air volume produced by the fan,
and will become higher when the number of components or parts in
the system is high; the curve T1 is an air volume curve
representing the operating characteristic of the fan with
overlapped blades measured in an air tunnel; the point P1 is an
intersection of the curve B1 with the curve T1 representing an
operating point of the system; and the circled area Q surrounding
the point P1 is an operating range representing the operating
performance of the fan with overlapped blades operated at
non-uniform rotating speeds to carry away the heat produced in the
system.
[0006] In the graph shown in FIG. 3, the curve T3 represents an air
volume curve for a fan having a motor with increased number of
coils in an attempt to upgrade the fan performance; and point P2 is
an intersection of the curve T3 with the system impedance curve B1
representing an operating point of the system. The operating point
P2 is obviously much higher than the operating point P1 at the
intersection of the curve T1 with the system impedance curve B1.
That is, the whole curve T3 is higher than the curve T1 and
represents the fan with motor having increased number of coils
provides increased air volume. However, the motor with increased
number of coil would largely increase the power consumption thereof
and tends to overheat and burn out due to increased rotating
speed.
[0007] It is therefore tried by the inventor to develop a fan
enabling increased air volume that increases air pressure and
volume without the need of increasing the power for drive the
fan.
SUMMARY OF THE INVENTION
[0008] A primary object of the present invention is to provide a
fan wheel having a plurality of blades that may be differently
arranged on a hub, so that the blades either overlap one another,
or have a blade root installation angle smaller than 53.degree. and
a blade tip inclination angle smaller than 46.degree., or have a
solidity of blade roots larger than 1.5 and a solidity of blade
tips larger than 1, so that the fan wheel is able to produce
increased air volume and enhanced cooling efficiency at a uniform
rotating speed.
[0009] Another object of the present invention is to provide a fan
wheel that operates at a uniform rotating speed to save power
consumption needed to drive the fan wheel.
[0010] To achieve the above and other objects, the fan enabling
increased air volume according to the present invention includes at
least a fan wheel and a driving unit for driving the fan wheel to
maintain a uniform rotating speed. The fan wheel includes a hub and
a plurality of blades radially extended from an outer periphery of
the hub.
[0011] In a first embodiment of the present invention, the blades
are arranged on the hub with a preceding blade overlapping a
following blade. In a second embodiment of the present invention,
the blades are arranged on the hub with a blade root installation
angle smaller than 53.degree. and a blade tip inclination angle
smaller than 46.degree.. In a third embodiment of the present
invention, the blades are arranged on the hub with a solidity of
blade roots larger than 1.5 and a solidity of blade tips larger
than 1. In either case, the fan wheel is able to produce increased
air volume and accordingly enhanced cooling power at the uniform
rotating speed.
[0012] Further scope of the applicability of the present invention
will become apparent from the detailed description given
hereinafter. However, it should be understood that the detailed
description and specific examples, while indicating preferred
embodiments of the invention, are given by way of illustration
only, since various changes and modifications within the spirit and
scope of the invention will become apparent to those skilled in the
art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The present invention will become more fully understood from
the following detailed description and the accompanying drawings,
which are given by way of illustration only, and thus are not
limitative of the present invention, and wherein:
[0014] FIG. 1 is a graph showing fan characteristic curves for a
conventional fan used with a system having a relatively small
number of components or parts arranged therein;
[0015] FIG. 2 is a graph showing fan characteristic curves for a
conventional fan with overlapped blades and used with a system
having a relatively large number of components or parts arranged
therein;
[0016] FIG. 3 is a graph comparing a fan characteristic curve for a
conventional fan having a motor with increased number of coils with
the fan characteristic curves shown in FIG. 2;
[0017] FIG. 4 is an exploded sectional view of a fan according to a
first preferred embodiment of the present invention;
[0018] FIG. 5 is an assembled sectional view of FIG. 4;
[0019] FIG. 6 is a top plan view of the fan according to the first
preferred embodiment of the present invention;
[0020] FIG. 7 is a graph showing a rotating speed deviation curve
for a fan having a uniform rotating speed according to the first
preferred embodiment of the present invention;
[0021] FIG. 8 is a graph comparing an air volume curve for the
uniform-speed fan according to the first preferred embodiment of
the present invention to fan characteristic curves for a
conventional fan having non-uniform rotating speeds and used with a
system having densely arranged internal components;
[0022] FIG. 9 is a top plan view of another fan according to the
first preferred embodiment of the present invention with blades
thereof overlapped in a second manner;
[0023] FIG. 10 is a top plan view of a further fan according to the
first preferred embodiment of the present invention with blades
thereof overlapped in a third manner;
[0024] FIG. 11 is a stretch-out sectional view showing blade roots
for a fan according to a second preferred embodiment of the present
invention;
[0025] FIG. 12 is a stretch-out view showing blade tips for the fan
according to the second preferred embodiment of the present
invention;
[0026] FIG. 13 shows a stretch-out view of a hub and sectioned side
view of blade roots for a fan according to a third preferred
embodiment of the present invention;
[0027] FIG. 14 shows the solidity of blade roots for the fan
according to the third preferred embodiment of the present
invention;
[0028] FIG. 15 shows a stretch-out view of a hub and sectioned side
view of blade tips for the fan according to the third preferred
embodiment of the present invention; and
[0029] FIG. 16 shows the solidity of blade tips for the fan
according to the third preferred embodiment of the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] Please refer to FIGS. 4, 5, and 6, in which a fan enabling
increased air volume according to a first preferred embodiment of
the present invention is shown. As shown, the fan of the present
invention includes at least a housing 21, a fan wheel 22, and a
driving unit 23. The fan wheel 22 includes a hub 221 and a
plurality of overlapped blades 222 that radially outward extend
from an outer periphery of the hub 221. Each of the blades 222
includes a blade root 2221 directly connected with the hub 221, a
blade body 2222 extended from the blade root 2221 and having a
first blade edge 2223 and a second blade edge 2224, and a blade tip
2225 located at an outer end of the blade body 2222. The blades 222
overlap one another in such a manner that the blade root 2221 and
an area including an upper part of the blade body 2222 and the
first blade edge 2223 of a preceding blade 222 overlaps the blade
root 2221 and an area including a lower part of the blade body 2222
and the second blade edge 2224 of a following blade 222. The hub
221 includes a spindle 2211 having a neck portion 22111 formed
thereon for a retaining ring 26 to engage therewith. The housing 21
includes a hub seat 211 with a hollow bushing 212 provided thereon
for a bearing 25 to mount therein. The driving unit 23 includes a
driving circuit board 231, a stator 232, and a rotor 233.
[0031] To assemble the fan of the present invention, first firmly
fix the rotor 233 in the hub 221 of the fan wheel 22, and then
sequentially position the retaining ring 26 and the bearing 25 in
the bushing 212, and then put the driving circuit board 231 and the
stator 232 around the bushing 212. Thereafter, extend the spindle
2211 of the fan wheel 22 through the bearing 25 with the retaining
ring 26 engaged with the neck portion 22111 of the spindle 2211, so
that the spindle 2211 is rotatably connected to the bushing 212
without the risk of separating from the bushing 212. Finally,
connect the driving circuit board 231 to the stator 232, which is
magnetically connected to the rotor 233, so that the stator 232 and
the rotor 233 are excited when the driving circuit board 231
produces currents. In this manner, the fan wheel 22 could rotate at
a uniform speed as soon as it is started, and produces
airflows.
[0032] Please refer to FIGS. 4 and 7 at the same time. The fan with
overlapped blades and operated at a uniform rotating speed, as
described with reference to FIGS. 4, 5, and 6, has a rotating speed
deviation curve F1 for a rotating speed preset for the fan. When
the curve F1, under the preset fixed rotating speed, indicates a
deviation within a range of .+-.8%, the air volume produced by the
fan increases gradually. That is, when the fan with overlapped
blades has a uniform rotating speed and a rotating speed deviation
of the fan between a starting speed and an end speed is limited to
a range of .+-.8%, the air volume produced by the fan increases.
And, when the rotating speed deviation between the starting speed
and the end speed is limited to 0%, the fan with overlapped blades
having a uniform rotating speed actually has a fixed rotating
speed, which allows the fan to produce further increased air
volume. The fan of FIG. 4 has an air volume curve T2 as shown in
FIG. 8. That is, the curve T2 is obtained when the fan with
overlapped blades 222 according to the first preferred embodiment
of the present invention rotates at a uniform speed. The curve T2
intersects with the system impedance curve B1 at a point that is a
system operating point P2. As can be seen from FIG. 8, the
operating point P2 of the fan with overlapped blades and uniform
rotating speed has a position in the operating area Q the same as
the position of the operating point P2 at the intersection of the
air volume curve T3 of the fan with motor having increased number
of coil with the system impedance curve B1, and is obviously higher
than the operating point P1 of the general fan with overlapped
blades and non-uniform rotating speed. That is, the air pressure
and air volume corresponding to the operating point P2 are
obviously higher than that corresponding to the operating point P1.
In other words, the whole air volume curve T2 indicates the fan of
the present invention having overlapped blades and uniform rotating
speed has an optimal operating performance to provide largely
increased air pressure and effective cooling of a system with
densely arranged internal components or parts. The fan of the
present invention eliminates the drawbacks existed in the
conventional fan with motor having increased number of coils, such
as increased power consumption and easy burnout of motor due to
high rotating speed thereof, while upgrades the fan performance to
produce increased air pressure and air volume without increasing
the power needed by the motor.
[0033] FIGS. 9 and 10 shows two fans according to the first
preferred embodiment of the present invention but have a plurality
of blades 222 overlapped one another in different manners. In FIG.
9, the blades 222 overlaps one another in such a manner that the
blade root 2221 of a preceding blade 222 overlaps the blade root
2221 of the following blade 222. In FIG. 10, the blades 222
overlaps one another in such a manner that the blade body 2222 of a
preceding blade 222 overlaps the blade body 2222 of the following
blade 222. In either case, the fan of the present invention
provides an optimal performance to produce increased air pressure
and enhanced cooling efficiency without increasing the power
consumption thereof.
[0034] Please refer to FIGS. 11 and 12 that are spread-out views of
a fan wheel 32 for a fan according to a second preferred embodiment
of the present invention to show a sectioned side view of blade
roots 3221 and a side view of blade tips 3225, respectively, of the
blades 322 on the fan wheel 32. The fan wheel 32 is structurally
and functionally similar to the fan wheel 22 in the first preferred
embodiment, except that the blades 322 on the fan wheel 32 do not
overlap one another, and the blade root 3221 connected with the hub
321 has an inclination equal to an angle contained between a blade
chord C3 at the blade root 3221 and a horizontal line. That is, the
blade root 3221 has an installation angle .theta.1 smaller than
53.degree.. Moreover, the blade tip 3225 of the blade 322 on the
hub 321 has an inclination equal to an angle contained between a
blade chord C4 at the blade tip 3225 and a horizontal line. That
is, the blade tip 3225 has an inclination angle .theta.2 smaller
than 46.degree.. With these arrangements, the fan according to the
second preferred embodiment of the present invention rotating at a
uniform speed can produce increased air pressure and air volume to
achieve an optimal performance and increased cooling efficiency
without increasing the power consumption thereof.
[0035] FIGS. 13 to 16 are spread-out views of a fan wheel 42 for a
fan according to a third preferred embodiment of the present
invention, wherein FIGS. 13 and 14 are sectioned side views of
blade roots 4221, and FIGS. 15 and 16 are side views of blade tips
4225 of the blades 422 on the fan wheel 42. The fan wheel 42 is
structurally and functionally similar to the fan wheel 22 in the
first preferred embodiment, except that the blades 422 on the fan
wheel 42 do not overlap one another, and a solidity of blade roots
of the blades 422 connected to the hub 421 is larger than 1.5. That
is, C1/S1>1.5, where C1 is referred to as a blade chord at the
blade root and represents a linear distance from an upper end
42211a to a lower end 42212a of a blade root 4221a of a blade 422a,
and S1 is a linear distance from the upper end 42211a of the blade
root 4221a of a blade 422a to the upper end 42211b of the blade
root 4221b of an adjacent blade 422b, or a linear distance from the
lower end 42212a of the blade root 4221a of a blade 422a to the
lower end 42212b of the blade root 4221b of an adjacent blade 422b
(see FIGS. 13 and 14). Moreover, a solidity of blade tips of the
blades 422 is larger than 1. That is, C2/S2>1, where C2 is
referred to as a blade chord at the blade tip and represents a
linear distance from an upper end 42251a to a lower end 42252a of a
blade tip 4225a of a blade 422a, and S1 is a linear distance from
the upper end 42251a of the blade tip 4225a of a blade 422a to the
upper end 42251b of the blade tip 4225b of an adjacent blade 422b,
or a linear distance from the lower end 42252a of the blade tip
4225a of a blade 422a to the lower end 42252b of the blade tip
4225b of an adjacent blade 422b (see FIGS. 15 and 16). With the
above arrangements, including the non-overlapped blades, a solidity
of blade roots larger than 1.5 and a solidity of blade tips larger
than 1, and a uniform rotating speed, the fan according to the
third preferred embodiment of the present invention can produce
increased air pressure and air volume to achieve an optimal
performance and increased cooling efficiency without increasing the
power consumption thereof.
[0036] The invention being thus described, it it will be obvious
that the same may be varied in many ways. Such variations are not
to be regarded as a departure from the spirit and scope of the
invention, and all such modifications as would be obvious to one
skilled in the art are intended to be included within the scope of
the following claims.
* * * * *