U.S. patent application number 13/181108 was filed with the patent office on 2012-02-02 for centrifugal fan.
Invention is credited to Myoungju Kang, Hosan Kim, Jindong Kim.
Application Number | 20120027597 13/181108 |
Document ID | / |
Family ID | 45526928 |
Filed Date | 2012-02-02 |
United States Patent
Application |
20120027597 |
Kind Code |
A1 |
Kang; Myoungju ; et
al. |
February 2, 2012 |
CENTRIFUGAL FAN
Abstract
A centrifugal fan according to an exemplary embodiment of the
present invention includes: a hub penetrated by a rotational axis;
a plurality of main blades extended in a radial direction from a
predetermined point of the top of the hub; a bell mouth formed on a
top of the exteriors of the plurality of main blades; and a
plurality of auxiliary blades extended in the radial direction
between the plurality of main blades, wherein a ratio (D1/D2) of an
inner diameter D1 to an outer diameter D1 of each of the auxiliary
blades is in the range of 07 to 0.9.
Inventors: |
Kang; Myoungju; (Seoul,
KR) ; Kim; Jindong; (Seoul, KR) ; Kim;
Hosan; (Seoul, KR) |
Family ID: |
45526928 |
Appl. No.: |
13/181108 |
Filed: |
July 12, 2011 |
Current U.S.
Class: |
416/183 |
Current CPC
Class: |
F04D 29/30 20130101;
F04D 29/666 20130101; F04D 29/282 20130101 |
Class at
Publication: |
416/183 |
International
Class: |
F01D 5/22 20060101
F01D005/22 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 27, 2010 |
KR |
10-2010-0072163 |
Claims
1. A centrifugal fan, comprising: a hub penetrated by a rotational
axis; a plurality of main blades extended in a radial direction
from a predetermined point of the top of the hub; a bell mouth
formed on a top of the exteriors of the plurality of main blades;
and a plurality of auxiliary blades extended in the radial
direction between the plurality of main blades, wherein a ratio
(D1/D2) of an inner diameter Dl to an outer diameter D1 of each of
the auxiliary blades is in the range of 07 to 0.9.
2. The centrifugal fan of claim 1, wherein the auxiliary blade is
extended on a bottom of the bell mouth and is spaced apart from the
hub.
3. The centrifugal fan of claim 2, wherein the width of the
auxiliary blade is smaller than that of the main blade.
4. The centrifugal fan of claim 2, wherein the length of the
auxiliary blade is larger than that of the main blade.
5. The centrifugal fan of claim 2, wherein one or plural main
blades are positioned between the adjacent auxiliary blades.
6. The centrifugal fan of claim 2, wherein a ratio (W1/W2) of the
width w1 of the trailing edge of the auxiliary blade to the width
W2 of the trailing edge of the main blade is in the range of 0.45
to 0.65.
7. The centrifugal fan of claim 2, wherein the inner diameter D1 of
the auxiliary blade is equal to or larger than the diameter of the
bottom of the hub.
8. The centrifugal fan of claim 2, wherein the inner diameter D1 of
the auxiliary blade is equal to or larger than the inner diameter
of the bell mouth.
Description
CROSS REFERENCES RELATED APPLICATIONS
[0001] The present application claims the benefits of priority to
Korean Patent Application No. 10-2010-0072163 (filed on Jul. 27,
2010), which is herein incorporated by reference in its
entirety.
THE BACKGROUND
[0002] 1. The Field
[0003] The present invention relates to a centrifugal fan.
[0004] 2. Description of the Related Art
[0005] A centrifugal fan suctions air in an axial direction and
discharges the air in a radial direction. The centrifugal fan may
be mounted on an evaporation chamber or a machine chamber of an air
conditioner and a refrigerator. In particular, in the case of the
refrigerator, an area of a cooled air passage is decreased in order
to increase a volume in the refrigerator, such that a passage
resistance is increased. In order to solve the problem, a
centrifugal fan having a high constant pressure property is
generally used.
[0006] However, a general centrifugal fan in the related art has
disadvantages to be described below.
[0007] Specifically, while the axial-direction flow is switched to
the radial-direction flow, air is discharged from a trailing edge
of a fan blade at an angle between the axial direction and the
radial direction. Therefore, a larger flow rate is generated from a
lower side than an upper side of the trailing edge of the fan
blade.
[0008] Accordingly, a large pressure difference between the upper
side and the lower side of the trailing edge is caused, and as a
result, some of the air discharged through the trailing edge flows
backward through a bell mouth mounted on the top of the blade.
Therefore, the flow is lost and noise increases and an eddy
phenomenon occurs at the upper side of the trailing edge, such that
fan efficiency deteriorates.
THE SUMMARY
[0009] The present invention has been made in an effort to solve
the problems.
[0010] An exemplary embodiment of the present invention provides a
centrifugal fan including: a hub penetrated by a rotational axis; a
plurality of main blades extended in a radial direction from a
predetermined point of the top of the hub; a bell mouth formed on a
top of the exteriors of the plurality of main blades; and a
plurality of auxiliary blades extended in the radial direction
between the plurality of main blades, wherein a ratio (D1/D2) of an
inner diameter D1 to an outer diameter D1 of each of the auxiliary
blades is in the range of 07 to 0.9.
[0011] The following effects can be achieved by the centrifugal fan
according to the exemplary embodiment of the present invention
configured as above.
[0012] First, a constant pressure and a flow rate of a fan are
increased by installing an auxiliary blade between main blades.
[0013] Second, since the flow rate increases at the same rpm, rpm
can decrease while the same flow rate is maintained, and as a
result, noise is reduced.
[0014] Third, a velocity distribution of a flow discharged through
a trailing edge of the auxiliary blade is substantially uniform,
such that a pressure difference between an upper side and a lower
side of the trailing edge is minimized, and as a result, a flow
property in which the discharged air flows backward is
improved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a perspective view of a centrifugal fan according
to an exemplary embodiment of the present invention.
[0016] FIG. 2 is a plan view of a centrifugal fan according to an
exemplary embodiment of the present invention.
[0017] FIG. 3 is a bottom view of a centrifugal fan according to an
exemplary embodiment of the present invention.
[0018] FIG. 4 is a side view of a centrifugal fan according to an
exemplary embodiment of the present invention.
[0019] FIG. 5 is a graph showing a comparison of a flow rate for
each rpm between a centrifugal fan according to an exemplary
embodiment of the present invention and a general centrifugal fan
with no auxiliary blade.
[0020] FIG. 6 is a graph showing a comparison of noise for each
frequency between a centrifugal fan according to an exemplary
embodiment of the present invention and a general centrifugal fan
with no auxiliary blade.
THE DETAILED DESCRIPTION
[0021] In the following detailed description of the preferred
embodiments, reference is made to the accompanying drawings that
form a part hereof, and in which is shown by way of illustration
specific preferred embodiments in which the invention may be
practiced. These embodiments are described in sufficient detail to
enable those skilled in the art to practice the invention, and it
is understood that other embodiments may be utilized and that
logical structural, mechanical, electrical, and chemical changes
may be made without departing from the spirit or scope of the
invention. To avoid detail not necessary to enable those skilled in
the art to practice the invention, the description may omit certain
information known to those skilled in the art. The following
detailed description is, therefore, not to be taken in a limiting
sense, and the scope of the present invention is defined only by
the appended claims.
[0022] Hereinafter, a centrifugal fan according to an exemplary
embodiment of the present invention will be described in detail
with reference to the accompanying drawings.
[0023] FIG. 1 is a perspective view of a centrifugal fan according
to an exemplary embodiment of the present invention, FIG. 2 is a
plan view of a centrifugal fan according to an exemplary embodiment
of the present invention, and FIG. 3 is a bottom view of a
centrifugal fan according to an exemplary embodiment of the present
invention.
[0024] Referring to FIGS. 1 to 3, the centrifugal fan 10 according
to the exemplary embodiment of the present invention includes a hub
11 penetrated by a rotational axis and having a circular cone shape
in which a diameter increases toward the bottom, a blade extended
with being rounded in a radial direction at an edge of the hub, and
a bell mouth 14 formed on the top of the blade.
[0025] Specifically, the blade includes main blades 12 extended
from the edge of the bottom of the hub and auxiliary blades 13 each
of which the top is connected to the bottom of the bell mouth 14.
The auxiliary blade 13 is provided between the main blade 12 to
improve flow loss caused by a difference in velocity and pressure
between an upper side and a lower side of a trailing edge of the
blade.
[0026] The hub 11 has the circular cone shape in which the diameter
increases toward the bottom to serve to diffuse air suctioned in a
rotational axial direction to a radial direction. In addition, the
main blade 12 extends in the radial direction starting from a point
spaced apart toward the center from the edge of the bottom of the
hub 11 by a predetermined distance. In addition, the main blade 12
is extended with being rounded at a predetermined curvature.
Further, the auxiliary blade 13 is shorter than the main blade 12
and does not contact the hub 11. That is, the auxiliary blade 13 is
connected to only the bell mouth 14.
[0027] Moreover, an outer diameter of the bell mouth 14 is larger
than that of the bottom of the hub 11. In addition, the inner edge
of the bell mouth 14 is rounded in an extending direction of the
rotational axis of the hub 11. In other words, the inner edge of
the bell mouth 14 is extended by a predetermined length with being
rounded toward the top of the hub 11.
[0028] Meanwhile, in the structure of the main blade 12, an end of
the main blade at the side of the hub 11 may be defined as a
leading edge 121 and an opposite end to the leading edge 121 may be
defined as a trailing edge 122. Of course, similarly, both ends of
the auxiliary blade 13 may also be defined as a leading edge 131
and a trailing edge 132.
[0029] Specifically, when the centrifugal fan 10 is viewed from the
top (FIG. 2), a diameter D1 of a circumference linking the leading
edges of the auxiliary blades 13 may be substantially equal to or
larger than the diameter of the bottom of the hub 11. In addition,
the trailing edges 122 and 132 of the main blade 12 and the
auxiliary blade 13 are positioned on the same circumference and may
be substantially equal to the diameter D2 of the bell mouth 14. In
other words, the diameter of the circumference passing the leading
edges 131 of the auxiliary blades 13 may be represented by D1 and
the diameter of the circumference passing the trailing edges 132
may be represented by D2.
[0030] Further, the diameter D1 of the circumference passing the
leading edges 131 of the auxiliary blades 13 may be equal to or
larger than an inner diameter of the bell mouth 14. In addition,
the auxiliary blade 13 may be interposed between one or two or more
main blades 12. Moreover, hereinafter, the diameter D1 of the
circumference passing the leading edges 131 of the auxiliary blade
13 is defined as an inner diameter of the auxiliary blade 13 and
the diameter D2 of the circumference passing the trailing edges 132
is defined as an outer diameter of the auxiliary blade 13.
[0031] Meanwhile, the inner diameter D1 of the auxiliary blade 13
may be larger than the diameter of the circumference linking the
leading edges 121 of the main blade 12, i.e., an inner diameter of
the main blade 12.
[0032] Further, a ratio (D1/D2) of the inner diameter to the outer
diameter of the auxiliary blade 13 is preferably in the range of
0.7 to 0.9 and this is a result extracted through tests performed
at several times.
[0033] FIG. 4 is a side view of a centrifugal fan according to an
exemplary embodiment of the present invention.
[0034] Referring to FIG. 4, the auxiliary blade 13 is extended by a
predetermined length toward the bottom of the hub 11 from the
bottom of the bell mouth 14. Herein, a length from an upper end to
a lower end of the trailing edge 132 of the auxiliary blade 13 is
defined as a width W1 of the trailing edge 132 of the auxiliary
blade 13. In another aspect, the width W1 may be the height of the
trailing edge 132 from the bottom of the bell mouth 14.
[0035] In addition, the main blade 12 is extended from a
predetermined point of the top of the hub 11. Further, a length
from an upper end to a lower end of the trailing edge 122 of the
main blade 12 is defined as a width W2 of the trailing edge 122 of
the auxiliary blade 12. In another aspect, the width W2 may be the
height of the trailing edge 122 from the bottom of the bell mouth
14.
[0036] Further, a ratio (W1/W2) of the trailing edge 132 of the
auxiliary blade 13 to the width of the trailing edge 122 of the
main blade 12 is preferably in the range of 0.45 to 0.65 and this
is also a result extracted through tests performed at several
times.
[0037] FIG. 5 is a graph showing a comparison of a flow rate for
each rpm between a centrifugal fan according to an exemplary
embodiment of the present invention and a general centrifugal fan
with no auxiliary blade.
[0038] Referring to FIG. 5, a flow rate generated by the
centrifugal fan 10 according to the exemplary embodiment of the
present invention is more than that of the general centrifugal fan
in the same rpm. Accordingly, when the same flow rate is generated,
since the rpm of the centrifugal fan 10 of the exemplary embodiment
of the present invention may be set to be less than that of the
general centrifugal fan, power consumption can be reduced.
[0039] FIG. 6 is a graph showing a comparison of noise for each
frequency between a centrifugal fan according to an exemplary
embodiment of the present invention and a general centrifugal fan
with no auxiliary blade.
[0040] Referring to FIG. 6, a sound pressure level (SPL) generated
in the centrifugal fan 10 according to the exemplary embodiment of
the present invention is lower than that of the general centrifugal
fan under the same frequency.
[0041] This means that the magnitude of noise generated in the
centrifugal fan 10 is smaller than that of the general centrifugal
fan at the same rpm or frequency. Accordingly, fan noise can be
reduced by using the centrifugal fan 10 according to the exemplary
embodiment of the present invention.
* * * * *