U.S. patent application number 16/567249 was filed with the patent office on 2020-03-19 for centrifugal fan.
The applicant listed for this patent is Yen Sun Technology Corp.. Invention is credited to Chien-Jung CHEN, Chih-Tsung HSU, Chan-Yi WU, Hsin-Hsien WU.
Application Number | 20200088209 16/567249 |
Document ID | / |
Family ID | 67953632 |
Filed Date | 2020-03-19 |
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United States Patent
Application |
20200088209 |
Kind Code |
A1 |
CHEN; Chien-Jung ; et
al. |
March 19, 2020 |
CENTRIFUGAL FAN
Abstract
A centrifugal fan includes a casing and an impeller module. The
casing defines an accommodating space having an air inlet and an
air outlet. The impeller module is mounted in the accommodating
space for allowing air flow to enter from the air inlet and exit
from the air outlet. The impeller module includes a body and a
plurality of blade units connected to and annularly distributed
along a circumference of the body. Each blade unit has a plurality
of blades arranged equi-angularly. A blade spacing which is defined
between each adjacent pair of the blades of one of the blade units
is different from a blade spacing which is defined between each
adjacent pair of the blades of another one of the blade units.
Inventors: |
CHEN; Chien-Jung; (Kaohsiung
City, TW) ; HSU; Chih-Tsung; (Kaohsiung City, TW)
; WU; Hsin-Hsien; (Kaohsiung City, TW) ; WU;
Chan-Yi; (Kaohsiung City, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Yen Sun Technology Corp. |
Kaohsiung City |
|
TW |
|
|
Family ID: |
67953632 |
Appl. No.: |
16/567249 |
Filed: |
September 11, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F04D 29/281 20130101;
F04D 29/666 20130101; F04D 29/30 20130101 |
International
Class: |
F04D 29/28 20060101
F04D029/28 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 14, 2018 |
TW |
107132408 |
Claims
1. A centrifugal fan comprising: a casing defining an accommodating
space that has an air inlet and an air outlet; and an impeller
module mounted in said accommodating space and rotatable about an
axis for allowing air flow to enter from said air inlet and exit
from said air outlet, said impeller module including a body and a
plurality of blade units connected to and annularly distributed
along a circumference of said body, each of said blade units having
a plurality of blades that are equi-angularly arranged along said
circumference of said body, a blade spacing which is defined
between each adjacent pair of said blades of one of said blade
units being different from a blade spacing which is defined between
each adjacent pair of said blades of another one of said blade
units.
2. The centrifugal fan as claimed in claim 1, wherein: said
plurality of blade units includes at least three blade units; the
blade spacings among said blade units are different; and said blade
units are arranged in the order of size of the blade spacings.
3. The centrifugal fan as claimed in claim 1, wherein said impeller
module includes exactly three blade units.
4. The centrifugal fan as claimed in claim 1, wherein said impeller
module includes exactly four blade units.
5. The centrifugal fan as claimed in claim 4, wherein said four
blade units includes two first blade units with one blade spacing
and two second blade units with a different blade spacing, said
first and second blade units being arranged in alternate.
6. A centrifugal fan comprising: a casing defining an accommodation
space that has an air inlet and an air outlet; and an impeller
module mounted in said accommodating space and rotatable about an
axis for allowing air flow to enter from said air inlet and exit
from said air outlet, said impeller module including a body and a
plurality of blade units connected to and annularly distributed in
a rotational direction along a circumference of said body, each of
said blade units having a plurality of blades with a blade spacing
being defined between each adjacent pair of said blades; wherein,
for each of said blade units, the blade spacings among said blades
are different, and said blades are arranged in a manner that the
blade spacings increases in the rotational direction.
7. The centrifugal fan as claimed in claim 6, wherein each blade
unit has four blades.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority of Taiwanese Patent
Application No. 107132408, filed on Sep. 14, 2018.
FIELD
[0002] The disclosure relates to a cooling fan, and particularly to
a centrifugal fan.
BACKGROUND
[0003] The centrifugal fan is one of the commonly used heat
dissipating devices, the characteristics of the air entering the
fan casing from an axial inlet opening near the shaft of the
impeller and being displaced from a radial outlet opening at one
side of the casing are particularly advantageous for the heat
dissipation of miniaturized electronic products. However, the
periodic changes in air pressure will occur in operation of the
centrifugal fan and lead to a source of noise. These periodic
changes in pressure are directly related to the number of fan
blades, the shape of fan blades, the distribution of fan blades,
and even the rotation speed of the impeller. In particular, when
the shape of the respective blades is the same and the distribution
of blade pitch is uniform, the noise from resonance of the fan
blades causing troubles in use.
[0004] Referring to FIG. 1, an impeller of a conventional
centrifugal fan 9 is shown to include a hub 90, a ring member 91
surrounding the hub 90, and a plurality of blades 92 radially
extending from the ring member 91. The arc distances (D) between
each two adjacent blades 92, with the same imaginary circular line
as a reference, are designed to exhibit continuous variations
according to the requirement of reducing noise. In the clockwise
direction (R) as depicted in FIG. 1, the arc distances (D) between
each two adjacent blades 92 gradually decrease from the 12 o'clock
position and then gradually increase from the 6 o'clock position.
That is, any two adjacent arc distances (D) of these blades 92 in
the same imaginary circular line are different, such that the
blades 92 to be rendered by unequal spacing arrangement, thereby
reducing the resonance of blades 92 and the noise generated during
rotation of the centrifugal fan 9.
[0005] However, in this way of design, if the running test result
of the centrifugal fan is not as expected, it must be re-adjusted
the appropriate spacing variation or spacing ratio variation one by
one for each blade 92, so that not only the time and cost of the
design are huge, but also relatively precise processes are required
for actual manufacturing in considering accurately matching the
design data, therefore, the costs of design and manufacturing are
bound to be high.
SUMMARY
[0006] Therefore, the object of the disclosure is to provide a
centrifugal fan capable of reducing noise with reduced design and
manufacturing costs.
[0007] According to the disclosure, a centrifugal fan includes a
casing and an impeller module. The casing defines an accommodating
space having an air inlet and an air outlet. The impeller module is
mounted in the accommodating space and is rotatable about an axis
for allowing air flow to enter from the air inlet and exit from the
air outlet. The impeller module includes a body and a plurality of
blade units connected to and annularly distributed along a
circumference of the body. Each of the blade units has a plurality
of blades that are equi-angularly arranged along the circumference
of the body. A blade spacing which is defined between each adjacent
pair of the blades of one of the blade units is different from a
blade spacing which is defined between each adjacent pair of the
blades of another one of the blade units.
[0008] Further, the present disclosure is to provide a variation of
the centrifugal fan capable of reducing noise with reduced design
and manufacturing costs.
[0009] Accordingly, this variation of the disclosed centrifugal fan
includes a casing and an impeller module. The casing defines an
accommodation space having an air inlet and an air outlet. The
impeller module is mounted in the accommodating space and is
rotatable about an axis for allowing air flow to enter from the air
inlet and exit from the outlet. The impeller module includes a body
and a plurality of blade units connected to and angularly
distributed in a rotational direction along a circumference of the
body. Each of the blade units has a plurality of blades with a
blade spacing being defined between each adjacent pair of the
blades. For each of the blade units, the blade spacings among the
blades are different, and the blades are arranged in a manner that
the blade spacings increases in the rotational direction.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Other features and advantages of the disclosure will become
apparent in the following detailed description of the embodiments
with reference to the accompanying drawings, of which:
[0011] FIG. 1 is a top view illustrating an impeller of a
conventional centrifugal fan;
[0012] FIG. 2 is a partly cross-sectional view illustrating a first
embodiment of a centrifugal fan according to the present
disclosure,
[0013] FIG. 3 is a top view of an impeller module of the first
embodiment;
[0014] FIG. 4 is a top view of an impeller module of a second
embodiment of the centrifugal fan according to the present
disclosure; and
[0015] FIG. 5 is a top view of an impeller module of a third
embodiment of the centrifugal fan according to the present
disclosure.
DETAILED DESCRIPTION
[0016] Before the present disclosure is described in greater
detail, it should be noted that where considered appropriate,
reference numerals or terminal portions of reference numerals have
been repeated among the figures to indicate corresponding or
analogous elements, which may optionally have similar
characteristics.
[0017] As shown in FIGS. 2 and 3, the first embodiment of a
centrifugal fan according to the present disclosure includes a
casing 1 which defines an accommodating space 100 having an air
inlet 101 and an outlet 102, and an impeller module 2 which is
mounted in the accommodating space 100 and which is rotatable about
an axis for allowing air flow to enter from the air inlet 101 and
then exit from the outlet 102.
[0018] In this embodiment, the impeller module 2 includes a body
20, and three blade units 21 connected to the body 20 and annularly
distributed along a circumference of the body 20. Each of the blade
units 21 has a plurality of blades 211 extending from the body 20
away from the axis, and are equi-angularly arranged along the
circumference of the body 20. In this embodiment, each adjacent
pair of the blades 211 of one of the blade units 21 defines a blade
spacing (X1) therebetween, each adjacent pair of the blades 211 of
another one of the blade units 21 defines a blade spacing (X2)
therebetween, and each adjacent pair of the blades 211 of the last
one of the blade units 21 defines a blade spacing (X3)
therebetween. The blade spacings (X1, X2, X3) among the blade units
21 are of different sizes, and the three blade units 21 are
arranged in the order of size of the predetermined blade spacings
(X1, X2, X3). With the full circle around the body 20 as a
reference, a blade unit 21 is formed every 120 degrees, with the
blade spacings of the three blade units 21 varied from (X1) to (X2)
and then to (X3), thereby providing asymmetrically distributed
blades 211 as a whole for the impeller module 2 of the first
embodiment.
[0019] Since the blades 211 of the impeller module 2 in the first
embodiment are asymmetrically distributed, the noise from resonance
during rotation of the impeller module 2 can be reduced. Further,
in the design of the first embodiment, it is only needed to provide
three blade units 21 with different blade spacings (X1, X2, X3),
thus obviating the necessity of adjusting the continuous spacing
variation between each adjacent blades 92 as illustrated in FIG. 1.
Therefore, it can effectively reduce the costs of design and
testing. In addition, because the design is relatively simple,
high-precision processes are not required, thereby reducing the
cost incurred in manufacturing.
[0020] It should be particularly noted that the first embodiment is
described by taking the form of three blade unit 21 as an example.
In actual implementation, for the consideration of other
requirements, four to six blade units 21 may be designed for an
impeller module 2 without excessive difficulty. This can also
provide an impeller module 2 with asymmetrically distributed blades
211 in terms of the blade spacing, and achieve the effect of
reducing the costs of design and manufacturing.
[0021] As shown in FIG. 4, the second embodiment of a centrifugal
fan of the present disclosure has a structure similar to that of
the first embodiment. The main difference between this embodiment
and the first embodiment resides in the following. The impeller
module 2 in this embodiment includes four blade units 21. The four
blade units 21 includes two first blade units 2101 with one blade
spacing (X4), and two second blade units 2102 with a different
blade spacing (X5). The first and second blade units 2101, 2102 are
arranged in alternate. In the second embodiment, since only two
different spacings (X4, X5) are used in the four blade units 21,
the resonance of blades 211 can be prevented in a simpler design to
achieve the purpose of reducing noise during operation.
[0022] As shown in FIG. 5, the third embodiment has a structure
similar to that of the first embodiment. The main difference
between this embodiment and the first embodiment resides in the
following. The blade unit 21 in this embodiment are annularly
distributed in a rotational direction (R1) along the circumference
of the body 20. Each of the blade units 21 has four blades 211 with
the blade spacings among the blades 211 being different.
Specifically, each of the blade units 21 has three blade spacings
(Y1, Y2, Y3), and the four blades 211 are arranged in a manner that
the blade spacings (Y1, Y2, Y3) increases in the rotational
direction (R1). Given that each blade unit 21 has four blades 211
with three different spacings (Y1, Y2, Y3), in the design of the
third embodiment, it is only needed to configure the three blade
spacings (Y1, Y2, Y3) rather than to adjust the continuous spacing
variation between each adjacent blades 92 as illustrated in FIG. 1,
so that the cost of design and testing can be effectively reduced
as in the first embodiment, which in turn reducing the cost
incurred in manufacturing.
[0023] To be particularly noted that the third embodiment is
described with respect to the blade units 21 with four blades 211
as an example, this embodiment may be implemented depending on the
actual requirements with appropriate adjustments. For example, each
blade unit 21 has only three blades 211, or has five blades 211,
the intended effect of this disclosure can still be achieved
without unduly raising the design difficulty.
[0024] In summary, the impeller module 2 of the centrifugal fan 2
of the present disclosure is designed in a relatively simple manner
to prevent the resonance of blades, thereby reducing the noise
during operation, and effectively reducing the costs of design,
testing, and manufacturing.
[0025] In the description above, for the purposes of explanation,
numerous specific details have been set forth in order to provide a
thorough understanding of the embodiments. It will be apparent,
however, to one skilled in the art, that one or more other
embodiments may be practiced without some of these specific
details. It should also be appreciated that reference throughout
this specification to "one embodiment," "an embodiment," an
embodiment with an indication of an ordinal number and so forth
means that a particular feature, structure, or characteristic may
be included in the practice of the disclosure. It should be further
appreciated that in the description, various features are sometimes
grouped together in a single embodiment, figure, or description
thereof for the purpose of streamlining the disclosure and aiding
in the understanding of various inventive aspects, and that one or
more features or specific details from one embodiment may be
practiced together with one or more features or specific details
from another embodiment, where appropriate, in the practice of the
disclosure.
[0026] While the disclosure has been described in connection with
what are considered the exemplary embodiments, it is understood
that this disclosure is not limited to the disclosed embodiments
but is intended to cover various arrangements included within the
spirit and scope of the broadest interpretation so as to encompass
all such modifications and equivalent arrangements.
* * * * *