U.S. patent application number 11/472370 was filed with the patent office on 2007-05-31 for fan assembly for vacuum cleaner.
This patent application is currently assigned to SAMSUNG GWANGJU ELECTRONICS CO., LTD.. Invention is credited to Seung-gee Hong, Sung-cheol Lee, Hyun-jun Oh, Hwa-gyu Song.
Application Number | 20070122277 11/472370 |
Document ID | / |
Family ID | 37781992 |
Filed Date | 2007-05-31 |
United States Patent
Application |
20070122277 |
Kind Code |
A1 |
Oh; Hyun-jun ; et
al. |
May 31, 2007 |
Fan assembly for vacuum cleaner
Abstract
The present invention relates to a fan assembly for a vacuum
cleaner for reducing BPF noises. The fan assembly includes a motor,
an impeller having a plurality of impeller blades, the impeller
being rotated by the motor to suck air, and a diffuser disposed to
wrap around an outer circumference of the impeller, the diffuser
having a plurality of diffuser blades arranged in a predetermined
interval. A ratio of an exit area of the diffuser to an entrance
area of the diffuser is determined to reduce noise generated when
the impeller rotates.
Inventors: |
Oh; Hyun-jun; (Gwangju-city,
KR) ; Hong; Seung-gee; (Suwon-si, KR) ; Song;
Hwa-gyu; (Gwangju-city, KR) ; Lee; Sung-cheol;
(Gwangju-city, KR) |
Correspondence
Address: |
BLANK ROME LLP
600 NEW HAMPSHIRE AVENUE, N.W.
WASHINGTON
DC
20037
US
|
Assignee: |
SAMSUNG GWANGJU ELECTRONICS CO.,
LTD.
|
Family ID: |
37781992 |
Appl. No.: |
11/472370 |
Filed: |
June 22, 2006 |
Current U.S.
Class: |
415/211.2 |
Current CPC
Class: |
F04D 29/663 20130101;
A47L 5/22 20130101; F04D 29/444 20130101 |
Class at
Publication: |
415/211.2 |
International
Class: |
F01D 9/00 20060101
F01D009/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 28, 2005 |
KR |
2005-114158 |
Claims
1. A fan assembly for a vacuum cleaner comprising: a motor, an
impeller having a plurality of impeller blades, the impeller being
rotated by the motor to suck air, and a diffuser disposed to wrap
around an outer circumference of the impeller, the diffuser having
a plurality of diffuser blades arranged at a predetermined
interval; wherein a ratio of an exit area of the diffuser to an
entrance area of the diffuser is set to reduce noise generated when
the impeller rotates.
2. The fan assembly for the vacuum cleaner of claim 1, wherein the
ratio of the exit area of the diffuser to the entrance area of the
diffuser satisfies a formula: 0.51 .ltoreq. DI DO .ltoreq. 0.62
##EQU3## where DI is the entrance area of the diffuser, and DO is
the exit area of the diffuser.
3. The fan assembly for the vacuum cleaner of claim 2, wherein the
diffuser is formed to satisfy the formula by controlling a number
of the diffuser blades.
4. The fan assembly for the vacuum cleaner of claim 2, wherein the
diffuser is formed to satisfy the formula by controlling an
inclined angle of each entrance of the plurality of diffuser
blades.
5. The fan assembly for the vacuum cleaner of claim 1, wherein the
ratio is also set to minimize a decrease in a suction force
produced by the fan assembly.
6. The fan assembly for the vacuum cleaner of claim 5, wherein the
ratio is approximately 0.51 and greater.
Description
REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit under 35 U.S.C. .sctn.
119(a) from Korean Patent Application No. 2005-114158 filed on Nov.
28, 2005 in the Korean Intellectual Property Office, the disclosure
of which is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a vacuum cleaner. More
particularly, the present invention relates to a fan assembly for a
vacuum cleaner.
[0004] 1. Description of the Related Art
[0005] Generally, a vacuum cleaner is an apparatus that sucks
contaminants with air by suction force, and then, separates and
collects contaminants from the sucked air using a contaminants
collecting apparatus. An example of the vacuum cleaner is shown in
FIG. 1.
[0006] Referring to FIG. 1, the vacuum cleaner 1 includes a suction
brush 2, an extension pipe assembly 3, and a main body 4.
[0007] The suction brush 2 is provided with a suction port (not
shown) at a bottom surface thereof, and sucks contaminants from a
cleaning surface. The extension pipe assembly 3 connects the
suction brush 2 with the main body 4 so as to form a pathway
through which sucked contaminants are moved. The main body 4 has a
contaminant collecting apparatus 6 and a fan assembly 7. The
contaminant collecting apparatus 6 separates contaminants from
sucked air and collects the separated contaminants. The contaminant
collecting apparatus 6 may be implemented by any of a general dust
bag or a cyclone dust collecting apparatus or so on. The fan
assembly 7 generates the suction force for sucking air and
contaminants.
[0008] The fan assembly 7 includes a motor 9, an impeller (not
shown), and a diffuser 8. The impeller is mounted on a rotation
shaft of the motor 9. The motor 9 rotates the impeller to generate
suction force, sucking air and contaminants. The diffuser 8 guides
air being discharged from the impeller to the motor 9 so that the
air cools the motor 9 and then is discharged outside through an
outlet 5 of the main body 4.
[0009] However, the fan assembly 7 generates a loud noise because
the impeller rotates at high speed inside the diffuser 8.
Especially, the impeller has a plurality of blades so that peak
noises are generated at BPF (Blade Passing Frequency) and at
integer multiply frequencies of the BPF. The peak noises are
referred to as BPF noises. Here, the BPF presents the number of
blades passing per second measured in cycles per second (Hz). BPF
noises do not greatly affect the whole noise level of the vacuum
cleaner, but they cause users to feel ill because they are high
frequency noises with strong tones.
SUMMARY OF THE INVENTION
[0010] The present invention has been developed in order to
overcome the above drawbacks and other problems associated with the
conventional arrangement. An aspect of the present invention is to
provide a fan assembly for a vacuum cleaner to reduce noise,
especially BPF noises, generated by an impeller. The above aspect
and/or other feature of the present invention can substantially be
achieved by providing a fan assembly for a vacuum cleaner, which
includes a motor; an impeller having a plurality of impeller
blades, the impeller being rotated by the motor to suck air, and a
diffuser disposed to wrap around an outer circumference of the
impeller, the diffuser having a plurality of diffuser blades
arranged in a predetermined interval. A ratio of an exit area of
the diffuser to an entrance area of the diffuser is determined to
reduce noise generated when the impeller rotates.
[0011] In one embodiment of the present invention, the ratio of an
exit area of the diffuser to an entrance area of the diffuser
satisfies a follow formula: 0.51 .ltoreq. DI DO .ltoreq. 0.62
##EQU1##
[0012] where DI is the entrance area of the diffuser, and DO is the
exit area of the diffuser.
[0013] The diffuser is formed to satisfy the formula by controlling
the number of the diffuser blades or an inclined angle of each
entrance of the plurality of diffuser blades.
[0014] The fan assembly for the vacuum cleaner according to an
embodiment of the present invention as described above can reduce
the BPF noises while minimizing the decrease of suction force.
[0015] Furthermore, with the fan assembly for the vacuum cleaner
according to an embodiment of the present invention, it is easy to
control a ratio of the diffuser exit area to the diffuser entrance
area by controlling the number of the diffuser blades or an
inclined angle of an entrance of the diffuser blade.
[0016] Other objects, advantages and salient features of the
invention will become apparent from the following detailed
description, which, taken in conjunction with the annexed drawings,
discloses preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] These and/or other aspects and advantages of the invention
will become apparent and more readily appreciated from the
following description of the embodiments, taken in conjunction with
the accompanying drawings of which:
[0018] FIG. 1 is a view illustrating a conventional vacuum
cleaner,
[0019] FIG. 2 is a sectional view illustrating a fan assembly for a
vacuum cleaner according to an embodiment of the present
invention;
[0020] FIG. 3 is a perspective view illustrating an impeller of the
fan assembly in FIG. 2;
[0021] FIG. 4 is a perspective view illustrating a diffuser of the
fan assembly in FIG. 2;
[0022] FIG. 5 is a plain view illustrating the diffuser of FIG.
4;
[0023] FIG. 6 is a partial perspective view illustrating a
diffusing channel of the diffuser of FIG. 5;
[0024] FIG. 7 is a partial plain view for explaining changes of a
sectional area of an entrance of a diffusing channel according to
changes of an inclined angle of an entrance of a diffuser
blade;
[0025] FIG. 8 is a graph illustrating a relationship between
suction force of a fan assembly and ratios of a diffuser exit area
to a diffuser entrance area; and
[0026] FIG. 9 is a graph illustrating a relationship between BPF
noises and ratios of a diffuser exit area to a diffuser entrance
area.
[0027] Throughout the drawings, like reference numerals will be
understood to refer to like parts, components and structures.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
[0028] Hereinafter, certain exemplary embodiments of the present
invention will be described in detail with reference to the
accompanying drawings.
[0029] The matters defined in the description, such as a detailed
construction and elements thereof are provided to assist in a
comprehensive understanding of the invention Thus, it is apparent
that the present invention may be carried out without those defined
matters. Also, well-known functions or constructions are omitted to
provide a clear and concise description of exemplary embodiments of
the present invention.
[0030] Referring to FIG. 2, a fan assembly 40 for a vacuum cleaner
according to an embodiment of the present invention includes a
motor 10, an impeller 20, and a diffuser 30.
[0031] The motor 10 rotates the impeller 20, and any of various
types of motors, which are generally used in vacuum cleaners, may
be used as the motor 10. The motor 10, in general, has a rotation
speed range of 30,000.about.36,000 rpm, and a capacity range of
1,000.about.2,000W.
[0032] Referring to FIG. 3, the impeller 20 is rotated by the motor
10 so as to generate suction force sucking air, and includes an
upper plate 22, a lower plate 21, and a plurality of impeller
blades 23.
[0033] The upper plate 22 is formed in a substantially disk shape,
and an air inlet 25 is formed at a center of the upper plate 22.
The lower plate 21 is formed a disk shape corresponding to the
upper plate 22 and a center of the lower plate 21 is fixed to a
motor shaft 11. The plurality of impeller blades 23 is radially
arranged at a predetermined interval between the upper plate 22 and
the lower plate 21. Each of the plurality of impeller blades 23 is
bent with a predetermined curvature. Therefore, air entering
through the air inlet 25 is discharged outside the impeller 20
through a plurality of air channels formed by the plurality of
impeller blades 23.
[0034] The diffuser 30 guides air discharged from the impeller 20
to the motor 10. Referring to FIGS. 4 and 5, the diffuser 30
includes a diffuser plate 32, a plurality of diffuser blades 31,
and a plurality of guiding blades 33.
[0035] The diffuser plate 32 is formed in a substantially disk
shape and is disposed between the impeller 20 and the motor 10. The
diffuser plate 32 has on a center thereof a boring hole 34 through
which the motor shaft 11 passes. The plurality of diffuser blades
31 is disposed on an upper surface of the diffuser plate 32 to wrap
around the impeller 20. In other words, the diffuser blades 31 are
radially disposed at a predetermined interval on an outer
circumference of the diffuser plate 32. A space between neighboring
diffuser blades 31 forms a diffusing channel 36. An impeller-side
end 31b of each of the diffuser blades 31 forms an entrance of the
diffusing channel 36. Each of the plurality of diffuser blades 31
is bent with a predetermined curvature as shown in FIG. 5. The
plurality of guiding blades 33 is radially disposed at a
predetermined interval on an under surface of the diffuser plate
32. A space between neighboring 2 guiding blades 33 forms a guiding
channel 37. The plurality of guiding blades 33 is formed to guide
air entered from the plurality of diffusing channels 36 to the
motor 10. A plurality of openings 35 is formed at each outer end of
the diffusing channels 36 on the diffuser plate 32 to fluidly
communicate the diffusing channels 36 and the guiding channels 37.
Each of the openings 35 covered by an upper cover 15 forms an exit
of each of the diffusing channels 36. Therefore, air passing
through each of the diffusing channels 36 flows to each of the
guiding channels 37 through the plurality of openings 35, and then,
is guided to the motor 10.
[0036] The upper cover 15 covers upper sides of both of the
impeller 20 and the diffuser 30 to form a space in which the
impeller 20 rotates. The upper cover 15 prevents air discharged
from the impeller 20 from leaking out a top end of the diffuser
30.
[0037] The inventors have determined that noise, especially BPF
noises, generated by the impeller 20 rotating inside the plurality
of diffuser blades 31 may be decreased while minimizing a decrease
of suction force of the fan assembly 40 if the diffuser 30 has a
ratio of a diffuser exit area to a diffuser entrance area within a
predetermined range. Then, the inventors have, through
experimentation, determined the predetermined range of the ratio of
the diffuser exit area to the diffuser entrance area that can
decrease the BPF noises of the impeller 20 while minimizing the
decrease of suction force of the fan assembly 40. Here, the
diffuser exit area means an exit area of the diffuser 30, and the
diffuser entrance area means an entrance area of the diffuser
30.
[0038] At this time, the diffuser entrance area is computed by
multiplying an entrance cross sectional area of one diffusing
channel 36 by the number of the diffuser blades 31. The entrance
cross sectional area of one diffusing channel 36, referring FIG. 6,
is computed by multiplying a height H of the diffuser blade 31 by a
length B of a vertical line from an entrance end 31b of the
diffuser blade 31 to next diffuser blade 31'. In other words, the
entrance cross sectional area of one diffusing channel 36 is
computed by Formula 1: CI=B.times.H (1)
[0039] where, CI is the entrance cross sectional area of one
diffusing channel 36, B is a length of a vertical line from an
entrance end of the diffuser blade 31 to next diffuser blade 31',
and H is a height of the diffuser blade 31.
[0040] Then, the diffuser entrance area is computed by Formula 2:
DI=CI.times.N (2)
[0041] where, DI is the diffuser entrance area, CI is the entrance
cross sectional area of one diffusing channel 36, and N is the
number of the diffuser blades 31.
[0042] Furthermore, the diffuser exit area is computed by
multiplying an opening area forming an exit of the diffusing
channel 36 by the number of the diffuser blades 31. Referring FIG.
5 and 7, the opening 35 of the diffusing channel 36 is formed at an
outer circumference of the diffuser plate 32 forming a bottom
surface of the diffusing channel 36.
[0043] Therefore, the diffuser exit area is computed by Formula 3:
DO=CO.times.N (3)
[0044] where, DO is the diffuser exit area, CO is the opening area
of the diffusing channel 36, and N is the number of the diffuser
blades 31.
[0045] Here, the ratio of the diffuser exit area to the diffuser
entrance area is defined as Formula 4: R = DI DO ( 4 ) ##EQU2##
[0046] where, R is the ratio of the diffuser exit area to the
diffuser entrance area, and DI is the diffuser entrance area, and
DO is the diffuser exit area.
[0047] The inventors have measured the changes of suction force and
BPF noises corresponding to the changes of the ratio of the
diffuser exit area to the diffuser entrance area of the fan
assembly 40 for the vacuum cleaner. The results are shown in Table
1, and FIGS. 8 and 9. TABLE-US-00001 TABLE 1 Area of Peak value of
Diffuser (mm.sup.2) BPF noises (dB) Suction Entrance Exit R
1.sup.st 2.sup.nd 3.sup.rd Total H force (W) 330 728 0.45 64.4 68.7
55.1 65.5 549 374 728 0.51 65.9 68.1 55.5 65.5 620 435 801 0.54
66.3 68.2 59.6 65.9 643 435 697 0.62 70.9 71.2 59.8 69.5 646 519
815 0.64 74.8 68.1 63.7 71.1 657 612 728 0.84 72.7 72.5 66.2 71.3
662
[0048] In one embodiment a motor 10 of the fan assembly 40 has a
capacity of 1800 W, and operates approximately at 31,000 rpm, 230
V, and 50 Hz. In the impeller 20, a maximum height is 17.4 mm, a
minimum height is 8 mm, an inner diameter, namely, a diameter of
the air inlet 25 is 35 mm, and an outer diameter is 109.6 mm (see
FIG. 3). In the diffuser 30, a height is 23.5 mm, a height of the
diffuser blade 31 is 10 mm, and an outer diameter is 130 mm (see
FIG. 4).
[0049] A curve shown in FIG. 8, and four straight lines 1, 2, 3,
and 4 shown in FIG. 9 illustrate the data of Table 1. In FIG. 9,
straight lines 1, 2, 3, and 4 indicate a first, a second, a third,
and a total BPF noise, respectively.
[0050] Referring to FIG. 8, suction force of the fan assembly 40
rises substantially in proportion to a rise in the ratio of the
diffuser exit area to the diffuser entrance area (hereinafter,
referred to as a diffuser area ratio), and then, when the diffuser
area ratio becomes over a predetermined value, the suction force
decreases. Therefore, referring to FIG. 8, a maximum suction force
of the fan assembly according to this embodiment is approximately
675 W. When the diffuser area ratio is 0.51, the suction force is
approximately 600 W. As a result, with the objective of minimizing
the decrease in suction force of the fan assembly 40 (the rate of
decrease is below 10%), it is preferable that the diffuser area
ratio is approximately 0.51 land over.
[0051] Referring to FIG. 9, as the diffuser area ratio decreases, a
first, a second, a third, and a total BPF noise 1, 2, 3, and 4
decrease. Also, as the diffuser area ratio increases, a fit a
second, a third and a total BPF noise 1, 2, 3, and 4 increase. As a
result, with the objective of keeping a first, a second, a third,
and a total BPF noise 1, 2, 3, and 4 of the fan assembly 40
approximately 70 dB and below, it is preferable that the diffuser
area ratio is approximately 0.62 and below.
[0052] As a result described above, with the objective of
minimizing the decrease of suction force and keeping a first, a
second, a third, and a total BPF noise 1, 2, 3, and 4 of the fan
assembly 70 dB and below, it is preferable that the diffuser 30 is
formed to have a range of the diffuser area ratio of
0.51.about.0.62.
[0053] Any one or both of the diffuser exit area and the diffuser
entrance area as described above may be controlled so that the
diffuser 30 has the substantially same size as the conventional
diffuser and the diffuser area ratio may come within the range
described above.
[0054] For an example, the diffuser exit area may be constant and
the diffuser entrance area is controlled so that the ratio of the
diffuser exit area to the diffuser entrance area is controlled. For
this purpose, below methods can be used.
[0055] First, controlling of the number of the diffuser blades 31
causes the diffuser entrance area to be controlled. At this time,
when the number of the diffuser blades 31 increases, a gap between
neighboring 2 diffuser blades 31 narrows thereby the diffuser area
ratio decreasing. As a result, the diffuser entrance area with
respect to the diffuser exit area decreases so that the diffuser
area ratio decreases. Contrarily, when the number of the diffuser
blades 31 decreases, a gap between neighboring 2 diffuser blades 31
widens thereby the diffuser area ratio increasing.
[0056] Second, controlling of an inclined angle .theta. of the
entrance of the diffuser blade 31 causes the diffuser entrance area
to be controlled. Here, the inclined angle .theta. of the entrance
of the diffuser blade 31 means an angle that an entrance end of the
diffuser blade 31 is inclined. Accordingly, the maximum inclined
angle of the entrance of the diffuser blade 31 is 90.degree.. When
the inclined angle .theta. of the entrance of the diffuser blade 31
is 90.degree., the diffuser entrance area is minimum. As the
inclined angle .theta. of the entrance of the diffuser blade 31
decreases, the diffuser entrance area increases. These are because
the diffuser entrance area is defined as an area of a section 38 of
the diffusing channel 36 at a point P where a top end 31a of the
diffuser blade 31 meets the inclined entrance end 31b of the
diffuser blade 31 (see FIG. 6).
[0057] Because the diffusing channel 36 is formed to diffuse from
the entrance to the exit, a gap between neighboring 2 diffuser
blades 31 and 31' becomes gradually wider from the entrance to the
exit. FIG. 7 is a plain view for explaining changes of gap
dimension between neighboring 2 diffuser blades 31 and 31'
corresponding to changes of the inclined angle .theta. of the
entrance of the diffuser blade 31. P is a first point where the top
end 31a of the diffuser blade 31 meets the inclined entrance end
31b of the diffuser blade 31 when the inclined angle of the
entrance of the diffuser blade is .theta. as shown in FIG. 6, B is
the gap dimension between the 2 diffuser blades 31 and 31' of this
case. P1 is a second point where the top end 31a of the diffuser
blade 31 meets the inclined entrance end 31b of the diffuser blade
31 when the inclined angle of the entrance of the diffuser blade 31
is more than .theta., B1 is the gap dimension between the 2
diffuser blades 31 and 31' of this case. P2 is a third point where
the top end 31a of the diffuser blade 31 meets the inclined
entrance end 31b of the diffuser blade 31 when the inclined angle
of the entrance of the diffuser blade 31 is less than .theta., B2
is the gap dimension between the 2 diffuser blades 31 and 31' of
this case. At this time, because a gap between neighboring 2
diffuser blades 31 and 31' becomes gradually wider from the
entrance of the diffusing channel 36 to the exit thereof, B
satisfies B1<B<B2. Accordingly, as the inclined angle .theta.
of the entrance of the diffuser blade 31 decreases, the diffuser
entrance area increases gradually. As a result, controlling of the
inclined angle .theta. of the entrance of the diffuser blade 31 can
cause the ratio of the diffuser exit area to the diffuser entrance
area to be controlled
[0058] Hereinafter, operation of the fan assembly 40 for the vacuum
cleaner with above-described structure will be explained in detail
with reference to FIGS. 2 to 4.
[0059] Upon rotating the motor 10, the impeller 20 fixed on the
motor shaft 11 is rotated. As the impeller 20 rotates, air is
sucked in through the air inlet 25, and then, is discharged to the
diffuser 30 through the exit of the impeller 20. The air discharged
from the impeller 20 is entered into each entrance of the plurality
of diffusing channels 36, and then, passes through each of the
diffusing channels 36 thereby being discharged to each of the
guiding channels 37 through the opening 35 that is an exit of the
diffusing channel 36. At this time, the ratio of the diffuser exit
area to the diffuser entrance area is a range of 0.51.about.0.62 so
that the BPF noises generated by impeller rotation are minimized.
The air entered into the guiding channels 37 passes through the
motor 10, and then, is discharged outside the main body through an
air outlet.
[0060] While the embodiments of the present invention have been
described, additional variations and modifications of the
embodiments may occur to those skilled in the art once they learn
of the basic inventive concepts. Therefore, it is intended that the
appended claims shall be construed to include both the above
embodiments and all such variations and modifications that fall
within the spirit and scope of the invention.
* * * * *