Title: Blowing fan and refrigerator having the same
Abstract: A blowing fan includes: a hub connected to a rotational shaft of a motor and receiving a driving force of the motor; and a plurality of blades connected at equal intervals in a circumferential direction of the hub and generating a blowing force, in which a connection between the blades and the hub has an area-reduced form in order to reduce a rigidity of the connection portion. The rigidity between a hub where a rotational shaft is fixed and a blade is weakened to lower a torsional resonant frequency of the rotational shaft. Thus, a noise of a refrigerator is considerably reduced.
Patent Number: 6,948,332 Issued on 09/27/2005 to Lee, et al.
| Inventors:
|
Lee; Dong Il (Seoul, KR);
Shin; Hyoun Jeong (Incheon, KR)
|
| Assignee:
|
LG Electronics Inc. (Seoul, KR)
|
| Appl. No.:
|
758105 |
| Filed:
|
January 16, 2004 |
Foreign Application Priority Data
| Nov 29, 2003[KR] | 10-2003-0086015 |
| Current U.S. Class: |
62/407; 62/419 |
| Intern'l Class: |
F25D 017/04 |
| Field of Search: |
62/407,419,446
416/228,203,235
|
References Cited [Referenced By]
U.S. Patent Documents
| 5326225 | Jul., 1994 | Gallivan et al.
| |
| 5536140 | Jul., 1996 | Wagner et al.
| |
| 6027307 | Feb., 2000 | Cho et al.
| |
| 6584799 | Jul., 2003 | Jung et al.
| |
| Foreign Patent Documents |
| 401325398 | Dec., 1998 | JP.
| |
Primary Examiner: Jones; Melvin
Attorney, Agent or Firm: Birch, Stewart, Kolasch & Birch, LLP
Claims
1. A blowing fan comprising:
a hub connected to a rotational shaft of a motor and receiving a driving force
of the motor; and
a plurality of blades connected at equal intervals in a circumferential direction
of the hub and generating a blowing force,
wherein a connection portion between the blades and the hub has an area-reduced
form in order to reduce a rigidity of the connection portion.
2. The blowing fan of claim 1, wherein a slot is formed at the connection portion
between the blade and the hub by removing a portion of the connection portion.
3. The blowing fan of claim 2, wherein the slot is formed by removing a portion
of the blade connected to the hub.
4. The blowing fan of claim 1, wherein a plurality of holes are formed at predetermined
intervals at the connection portion between the blade and the hub.
5. The blowing fan of claim 4, wherein the holes are formed at predetermined
intervals at the connection portion of the blade connected to the hub.
6. A refrigerator comprising:
a main body;
a freezing chamber formed at an upper portion of the main body;
a refrigerating chamber formed at a lower portion of the main body; and
a blowing fan disposed at a rear portion of the main body and blowing cooling
air required for the freezing chamber and the refrigerating chamber,
wherein the blowing fan comprises:
a hub connected to a rotational shaft of a motor and receiving a driving force
of the motor; and
a plurality of blades connected at equal intervals in a circumferential direction
of the hub and generating a blowing force,
wherein a connection portion between the blades and the hub has an area-reduced
form in order to reduce a rigidity of the connection portion.
7. The refrigerator of claim 6, wherein a slot is formed at the connection portion
between the blade and the hub by removing a portion of the connection portion.
8. The refrigerator of claim 7, wherein the slot is formed by removing a portion
of the blade connected to the hub.
9. The refrigerator of claim 6, wherein a plurality of holes are formed at predetermined
intervals at the connection portion between the blade and the hub.
10. The refrigerator of claim 9, wherein the holes are formed at predetermined
intervals at the connection portion of the blade connected to the hub.
11. The blowing fan of claim 1, wherein at least a hole is formed at the connection
portion between the blade and the hub.
12. The refrigerator of claim 6, wherein at least a hole is formed at the connection
portion between the blade and the hub.
Description
This Nonprovisional application claims priority under 35 U.S.C. § 119(a)
on Patent Application No(s). 10-2003-0086015 filed in Korea on Nov. 29, 2003, the
entire contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a blowing fan and, more particularly, to a blowing
fan for a refrigerator capable of reducing a resonance noise according to a torsional
resonance generated in driving a fan and avoiding a resonant frequency by lowering
a torsional resonant frequency of a rotational shaft connecting the fan and a motor.
2. Description of the Background Art
In general, a refrigerator is divided into a freezing chamber for keeping frozen
food items and a refrigerating chamber for keeping refrigerating food items, and
includes a refrigerating cycle for supplying cooling air to the freezing chamber
and the refrigerating chamber.
FIG. 1 is a front view of a refrigerator in accordance with a refrigerator.
The conventional refrigerator includes a main body 104 having a predetermined
space for storing food items and a door 102 mounted at its front side for
opening and closing; a freezing chamber 106 formed at an upper portion of
the main body 104 and storing frozen food items; a refrigerating chamber
110 sectioned from the freezing chamber 106 by a barrier 108,
formed at a lower portion of the main body 104, and storing refrigerating
food items; and a refrigerating cycle for supplying cooling air to the freezing
chamber 106 and the refrigerating chamber 110.
At a rear side of the freezing chamber 106, there is provided a space partitioned
by a shroud 112, in which a heat exchanger 114 provides cooling air
through heat-exchanging with a refrigerant, a axial-flow fan 118 blows air
cooled while passing the heat exchanger 114 to the freezing chamber 106
and the refrigerating chamber 110, and a motor 120 is connected to
the axial-flow fan 118 by a rotational shaft 122 to rotate the axial-flow
fan 118.
As shown in FIG. 2, the axial-flow fan 118 includes a hub 150 into
which the rotational shaft 122 of the motor 120 is fixed so as to
receive a rotational force of the motor 120, and a plurality of blades 152
arranged at predetermined intervals at an outer circumference of the hub 150
and generating a flowing force.
The blade 152 is extended in a curved-surface form from the outer circumference
of the hub 150, and in general, five blades are provided.
The operation of the refrigerator constructed as described will now be described.
When the axial-flow fan 118 is rotated according to driving of the motor
120, cooling air passes through the heat exchanger 114 and blows
to the freezing chamber 106 and the refrigerating chamber 110, thereby
performing a cooling operation. The cooling operation-completed air is sent back
to the heat exchanger 114.
Since the refrigerator has a large capacity and its internal temperature is
to be uniformly maintained to keep food items fresh for a long period, the method
of discharging cooling air in several directions in the refrigerating chamber is adopted.
Accordingly, a cooling passage for guiding cooling air in each direction
in the refrigerating chamber is long and complicate, generating much passage resistance
to the flow of cooling air.
Thus, in order to smoothly and quickly circulate cooling air under such a high
passage resistance, the axial-flow fan 118 needs to be rotated at a high
speed. However, rotation of the axial-flow fan 118 at a high speed causes
a torsional resonance phenomenon at the rotational shaft 122, which is a
main reason of a noise of a refrigerator.
Thus, in order to solve such a noise problem, researches related to noise reduction
are actively ongoing by using a shape designing of the rotational shaft 122
(notch, stepped shaft), a rotational inertia moment increase/decrease designing,
or a coupling designing of the rotational shaft 122 and the axial-flow fan 118.
In this respect, however, in the conventional refrigerator, the design change
in the rotational shaft 122 for the purpose of reducing the noise generated
due to the torsional resonance phenomenon of the rotational shaft 122 necessarily
accompanies a design change in parts coupled to the rotational shaft 122.
Then, a unit cost would be increased, a productivity would be degraded, and a quality
management wouldn't be easy due to the design change in many parts.
SUMMARY OF THE INVENTION
Therefore, an object of the present invention is to provide a blowing
fan designed to lower rigidity between a hub in which a rotational shaft is fixed
and blades to reduce a torsional resonant frequency of the rotational shaft to
thereby considerably reduce a noise of a refrigerator, and a refrigerator using
the blowing fan.
To achieve these and other advantages and in accordance with the purpose of the
present invention, as embodied and broadly described herein, there is provided
a blowing fan including: a hub connected to a rotational shaft of a motor and receiving
a driving force of the motor; and a plurality of blades connected at equal intervals
in a circumferential direction of the hub and generating a blowing force, in which
a connection between the blades and the hub has an area-reduced form in order to
reduce a rigidity of the connection portion.
A slot is formed at the connection portion between the blade and the hub by removing
a portion of the connection portion.
To achieve the above objects, there is also provided a refrigerator including:
a main body; a freezing chamber formed at an upper portion of the main body; a
refrigerating chamber formed at a lower portion of the main body; and a blowing
fan disposed at a rear portion of the main body and blowing cooling air required
for the freezing chamber and the refrigerating chamber, wherein the blowing fan
includes: a hub connected to a rotational shaft of a motor and receiving a driving
force of the motor; and a plurality of blades connected at equal intervals in a
circumferential direction of the hub and generating a blowing force, in which a
connection portion between the blades and the hub has an area-reduced form in order
to reduce a rigidity of the connection portion.
The foregoing and other objects, features, aspects and advantages of the present
invention will become more apparent from the following detailed description of
the present invention when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are included to provide a further understanding
of the invention and are incorporated in and constitute a part of this specification,
illustrate embodiments of the invention and together with the description serve
to explain the principles of the invention.
In the drawings:
FIG. 1 is a sectional view showing a refrigerator in accordance with a conventional art;
FIG. 2 is a front view of an axial-flow fan for the refrigerator in accordance
with the conventional art;
FIG. 3 is a sectional view of a refrigerator in accordance with the present invention;
FIG. 4 is a side view of an axial-flow fan for a refrigerator in accordance
with one embodiment of the present invention;
FIG. 5 is a front view of an axial-flow fan for a refrigerator in accordance
with one embodiment of the present invention;
FIG. 6 is a front view of an axial-flow fan for a refrigerator in accordance
with another embodiment of the present invention; and
FIGS. 7A and 7B are graphs comparatively showing noise generated from the axial-flow
fan of the present invention and that of the conventional art.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to the preferred embodiments of the
present invention, examples of which are illustrated in the accompanying drawings.
A blowing fan for a refrigerator in accordance with a preferred embodiment of the
present invention will now be described with reference to the accompanying drawings.
There can be several embodiments of the blowing fan for a refrigerator, of
which most preferred one will now be described.
FIG. 3 is a sectional view of a refrigerator in accordance with the present
invention, FIG. 4 is a side view of an axial-flow fan for a refrigerator in accordance
with one embodiment of the present invention, and FIG. 5 is a front view of an
axial-flow fan for a refrigerator in accordance with one embodiment of the present invention.
The refrigerator of the present invention includes a main body
6 having
a predetermined space for storing food items and a freezing chamber door
2
and a refrigerating door
4 installed at its front side to be respectively
opened and closed; a freezing chamber
8 formed at an upper portion of the
main body
8 and storing refrigerating food items; a refrigerating chamber
10 partitioned by a barrier
12 from the freezing chamber
8,
formed at a lower portion of the main body
6 and storing refrigerating food
items; and a refrigerating cycle disposed at a rear side of the main body
6
and generating cooling air required for the freezing chamber
8 and the refrigerating
chamber
10.
A compressor
14 for compressing a refrigerant is disposed at a rear side
of the main body
6, and a space
18 is prepared by being partitioned
by a shroud
16 at a rear side of the freezing chamber
8. In the space
16, there are installed a heat exchanger
20 to which a refrigerant
is introduced after being compressed by the compressor
14 for a heat exchanging,
and a blowing fan
22 for blowing air which has been cooled while passing
the heat exchanger
20 into the freezing chamber
8 and the refrigerating
chamber
10.
As shown in FIGS. 4 and 5, the blowing fan
22 includes a hub
28
connected to a motor
24 by a rotational shaft
26 and receiving a
driving force of the motor
24, and a plurality of blades
30 arranged
at equal intervals at an outer circumference of the hub
28 and generating
a blowing force.
A connection portion
32 between the hub
28 and the blade
30
has a structure aimed for reducing a torsional rigidity in order to lower a torsional
resonant frequency of the rotational shaft
26.
That is, if the rigidity of the connection portion
32 connecting the
hub
28 and the blade
30 is strong, when the blowing fan
22
is driven, a torsional vibration is generated, causing a torsional resonance phenomenon
at the rotational shaft
26.
Thus, by reducing the torsional rigidity of the connection portion
32
between the hub
28 and the blade
30, the torsional resonance phenomenon
of the rotational shaft
26 is reduced, so that the torsional resonant frequency
generated when the blowing fan
22 is driven can be lowered.
The torsional rigidity reduction structure of the connection portion
32
between the hub
28 and the blade
30 will now be described in detail.
As shown in FIG. 5, the rigidity of the connection portion between the hub
28
and the blade
30 is reduced by reducing an area of the connection portion
32 connected to the outer circumference of the hub
28.
In detail, the connection portion
32 is connected to the outer circumference
of the hub
28 as long as the length (L), and a slot
34 as long as
the length (M) is formed opened by removing one side of the connection portion
between the hub
28 and the blade
30.
Accordingly, the connection rigidity of the blade
30 weakens,
and when an air resistance is applied to the blade
30, the blade
30
itself absorbs the vibration to thereby reduce vibration transferred to the hub
28.
At this time, although the blade connection portion
32 has a reduced rigidity,
it can generate a sufficient blowing force and has such a sufficient rigidity to
be maintained and attached to the outer circumference of the hub
28.
FIG. 6 is a front view of an axial-flow fan for a refrigerator in accordance
with another embodiment of the present invention.
A blowing fan
50 in accordance with the second embodiment of the present
invention has a structure to reduce a rigidity of the connection portion
32
where the blade
30 and the hub
28 are connected. A plurality of holes
52 are formed at regular intervals at the connection portion
32 to
reduce a connection strength between the blade
30 and the hub
28.
One or more holes
52 are formed at the connection portion
32 between
the hub
28 and the blade
30 to thereby reduce a connection area between
the blade
30 and the hub
28.
The blowing fan for a refrigerator in accordance with the present invention is
operated as follows.
When power is applied to the refrigerator, the heat exchanger
20 is operated
and the flowing fan
22 is driven. Then, cooling air passes, which has passed
through the heat exchanger
20, is supplied to the freezing chamber
8
and the refrigerating chamber
10 according to driving of the blowing fan
22, performing a cooling operation. The cooling operation-finished air is
introduced into the heat exchanger
20.
At this time, by applying the blowing fan
22 adapted for reducing the
torsional
rigidity of the connection portion
32 between the hub
28 and the
blade
30, the torsional resonance phenomenon of the rotational shaft
26
can be reduced to lower the torsional resonant frequency generated when the blowing
fan
22 is driven.
FIGS. 7A and 7B are graphs comparatively showing noise generated from the axial-flow
fan of the present invention and that of the conventional art.
As shown in FIG. 7A, a comparison of each resonance rotational number generated
from the blowing fan installed in the freezing chamber of the refrigerator shows
that when the conventional axial flow fan is applied, a noise (T
1) has a
level of 45 dB(A) at about 1300 rpm, whereas when the blowing fan of the present
invention is applied, a noise (T
2) has a level of 43 dB(A) at about 1100
rpm. That is, application of the blowing fan according to the present invention
can reduce the resonant rpm of more than about 200 rpm compared to the conventional
axial flow fan.
And as shown in FIG. 7B, a comparison of each resonant rpm generated from the
blowing fan installed in a mechanic chamber of the refrigerator shows that when
the conventional axial flow fan is applied, a noise (T
1) has a level of
about 39 dB(A) at about 1200 rpm, whereas when the blowing fan of the present invention
is applied, a noise (T
2) has a level of 30 dB(A) at about 1000 rpm. That
is, application of the blowing fan of the present invention can reduce the resonant
rpm of more than about 200 rpm compared to the conventional axial flow fan.
As so far described, the blowing fan in accordance with the present invention
has the following advantages.
That is, for example, since the slot is formed at the connection portion between
the blade and the hub to lower the connection rigidity, when an air resistance
is generated at the blade, the blade itself is elastically deformed to absorb the
vibration, reducing the vibration transferred from the blade to the hub. Accordingly,
a torsional resonance of the rotational shaft connected to the motor is lowered,
so vibration generated from the blowing fan
22 can be reduced.
As the present invention may be embodied in several forms without departing from
the spirit or essential characteristics thereof, it should also be understood that
the above-described embodiments are not limited by any of the details of the foregoing
description, unless otherwise specified, but rather should be construed broadly
within its spirit and scope as defined in the appended claims, and therefore all
changes and modifications that fall within the metes and bounds of the claims,
or equivalence of such metes and bounds are therefore intended to be embraced by
the appended claims.
*
