U.S. patent application number 11/206905 was filed with the patent office on 2006-06-15 for vacuum cleaner impeller and motor assembly.
This patent application is currently assigned to SAMSUNG GWANGJU ELECTRONICS CO., LTD.. Invention is credited to Myung-won Lee, Sung-cheol Lee, Hyun-jun Oh, Hwa-gyu Song.
Application Number | 20060127240 11/206905 |
Document ID | / |
Family ID | 35311598 |
Filed Date | 2006-06-15 |
United States Patent
Application |
20060127240 |
Kind Code |
A1 |
Lee; Sung-cheol ; et
al. |
June 15, 2006 |
Vacuum cleaner impeller and motor assembly
Abstract
An impeller reduces peak noise in the frequency range of
8.about.10 khz and is constructed, in disclosed embodiments, with a
lower plate in a shape of a disk, an upper plate spaced apart from
the lower plate by a predetermined distance and having a diameter
corresponding with a diameter of the lower plate and a central air
inlet, and a plurality of air guide members disposed radially
between the lower plate and the upper plate having their outside
corners chamfered.
Inventors: |
Lee; Sung-cheol;
(Gwangju-city, KR) ; Song; Hwa-gyu; (Gwangju-city,
KR) ; Oh; Hyun-jun; (Gwangju-city, KR) ; Lee;
Myung-won; (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: |
35311598 |
Appl. No.: |
11/206905 |
Filed: |
August 19, 2005 |
Current U.S.
Class: |
417/366 |
Current CPC
Class: |
A47L 5/22 20130101; A47L
9/0081 20130101; F05D 2240/304 20130101; F04D 29/30 20130101; F04D
29/282 20130101 |
Class at
Publication: |
417/366 |
International
Class: |
F04B 39/06 20060101
F04B039/06 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 9, 2004 |
KR |
2004-0103355 |
Feb 23, 2005 |
KR |
2005-0015069 |
Claims
1. An impeller for a vacuum cleaner comprising: a lower plate in a
shape of a disk; an upper plate spaced apart from the lower plate
by a predetermined distance, the upper plate having a diameter
corresponding with a diameter of the lower plate and an air inlet
in the center thereof; and a plurality of air guide members
disposed radially between the lower plate and the upper plate, the
air guide members chamfered at both outside ends thereof
2. The impeller for the vacuum cleaner of claim 1, wherein a
dimension of the chamfered corner satisfies the formula 1.5
mm.ltoreq.B.ltoreq.C/2, where B is the widthwise dimension of the
chamfered corner, and C is the width of the air guide member.
3. The impeller for the vacuum cleaner of claim 1, wherein a
lengthwise dimension of the chamfered corner is between
approximately 1.5 mm and 3 mm.
4. An impeller for a vacuum cleaner comprising: a lower plate in a
shape of a disk; a plurality of air guide members disposed radially
on the lower plate, the plurality of air guide members having
chamfered corners at outside ends thereof; and an upper plate
disposed on the plurality of air guide members, the upper plate
having a central air inlet and a diameter corresponding to a
lengthwise beginning point of the chamfered corner of the air guide
member.
5. The impeller for the vacuum cleaner of claim 4, wherein a
dimension of the chamfered corners satisfies the formula 1.5
mm.ltoreq.B.ltoreq.C/2, where B is the widthwise dimension of the
chamfered corner, and C is the width of the air guide member.
6. The impeller for the vacuum cleaner of claim 4, wherein a
lengthwise dimension of the chamfered corners is between
approximately 1.5 mm and 3 mm.
7. A motor assembly for a vacuum cleaner comprising; a motor; an
impeller comprising, a lower plate disposed at a motor shaft of the
motor, the lower plate in a shape of a disk, an upper plate spaced
apart from the lower plate by a predetermined distance, the upper
plate having a central air inlet and a diameter corresponding with
a diameter of the lower plate, and a plurality of air guide members
disposed radially between the lower plate and the upper plate, the
air guide members having both outside corners chamfered; and a
diffuser disposed at an upper portion of the motor, the diffuser
guiding intake air from the impeller toward the motor.
8. The motor assembly for the vacuum cleaner of claim 7, wherein a
dimension of the chamfered corners satisfies the formula 1.5
mm.ltoreq.B.ltoreq.C/2 where, B is the widthwise dimension of the
chamfered corner, and C is the width of air guide member.
9. The motor assembly for the vacuum cleaner of claim 7, wherein a
lengthwise length of the chamfered corners is approximately between
1.5 mm and 3 mm.
10. A motor assembly for a vacuum cleaner comprising; a motor; an
impeller comprising, a lower plate in a shape of a disk, a
plurality of air guide members disposed radially on the lower
plate, the plurality of air guide members chamfered at both outside
corners thereof, and an upper plate disposed on the plurality of
air guide members, the upper plate having a diameter corresponding
with a lengthwise beginning point of the chamfered corner of the
air guide member and a central air inlet thereof; and a diffuser
disposed at an upper portion of the motor, the diffuser guiding
intake air from the impeller toward the motor.
11. The motor assembly for the vacuum cleaner of claim 10, wherein
a dimension of the chamfered corners satisfies the formula 1.5
mm.ltoreq.B.ltoreq.C/2 where, B is the widthwise dimension of the
chamfered corner, and C is the width of the air guide member.
12. The motor assembly for the vacuum cleaner of claim 10, wherein
a lengthwise dimension of the chamfered corner is between
approximately 1.5 mm and 3 mm.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit under 35 U.S.C.
.sctn.119(a) of Korean Patent Application Nos. 2004-103355 filed on
Dec. 9, 2004 and 2005-15069 filed on Feb. 23, 2005 in the Korean
Intellectual Property Office, the disclosures of which are
incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of The Invention
[0003] The present invention relates generally to the field of
vacuum cleaners. Some of the embodiments disclosed are directed
more particularly to an impeller for a vacuum cleaner motor
assembly.
[0004] 2. Description of The Related Art
[0005] Generally, a vacuum cleaner generates a partial vacuum and
collects dust and impurities by the partial vacuum. Therefore, the
vacuum cleaner has a motor assembly for generating the partial
vacuum. The partial vacuum is generated by an impeller that draws
in air as it is rotated by a motor.
[0006] Referring to FIGS. 1 and 2, a conventional motor assembly 1
includes a motor 10, an impeller 20 rotated by the motor 10 and a
diffuser 30 guiding air drawn in by the impeller 20 toward the
motor 10.
[0007] The impeller 20 has a lower plate 21, an upper plate 22 and
a plurality of air guide members 23. The lower plate 21 is formed
in the shape of a disk and disposed at a motor shaft 11 of the
motor 10. The upper plate 22 is formed in the shape of a disk to
correspond with the lower plate 21 and has a substantially same
diameter as the lower plate 21. The upper plate 22 has an air inlet
25 drawing in air at its center. A plurality of air guide members
23 are disposed radially between the lower plate 21 and the upper
plate 22 at regular intervals. Each of the air guide members 23 is
formed in the shape of a bent band having a predetermined
curvature. In an embodiment, one end 23a of the air guide members
23 is formed with right angles at peripheries of the lower plate 21
and the upper plate 22. Also, the air guide member 23 has a length
such that its outside end 23a is within the periphery of lower
plate 21 and upper plate 22, and its inside end is outside of the
air inlet 25 of the upper plate 22.
[0008] The diffuser 30 is disposed at an upper end of the motor 10
in concentric circles outside the impeller 20. There is a gap
between the diffuser 30 and the impeller 20 to rotate the impeller
20. The diffuser 30 has a plurality of guide members for guiding
the air when the air is drawn in and discharged by the impeller 20
toward the motor 10.
[0009] The operation of the conventional motor assembly 1
comprising the same structure as that described above will be
explained hereinafter referring to FIGS. 1 and 2.
[0010] When the motor 10 of the motor assembly 1 rotates, the
impeller 20 is rotated by the lower plate 21 disposed at the motor
shaft 11 of the motor 10. When the impeller 20 rotates, the
dust-laden air, which may contain dust and impurities, is drawn in
through a dust inlet of a suction brush (not shown) fluidly
connected with the air inlet 25 of the upper plate 22 of the
impeller 20. Dust and impurities in the air are removed while
passing through a dust-collecting unit (not shown), and
accordingly, substantially clean air enters the air inlet 25 of the
impeller 20. The air entered into the air inlet 25 flows along the
plurality of air guide members 23 and discharges toward the
diffuser 30. The air discharged from the diffuser 30 cools the
motor 10 and is discharged outside the vacuum cleaner through an
outlet of a main body thereof (not shown).
[0011] However, since the motor 10 rotates at high speed, the
vacuum cleaner, which collects the dust and impurities by the
suction force of the motor assembly 1, generates considerable
noise. Accordingly, efforts have been made to reduce the noise. One
approach is to change the flow passage of air discharged through
the motor assembly. Another is to provide sound-absorbing
materials. However, these methods do not efficiently reduce noise.
The inventors have found that it is desirable to reduce a noise
peak at a frequency of 8.about.10 khz, in particular, among the
noises that are generated by rotating of the impeller of the motor
assembly, to make operation more pleasant for the user.
SUMMARY OF THE INVENTION
[0012] In some embodiments, an impeller for a vacuum cleaner is
provided that reduces peak noise generated during rotation of the
impeller, particularly (for example) in the frequency range of
8.about.10 khz.
[0013] In further embodiments, a motor assembly is provided with a
noise-reducing impeller.
[0014] In some of the exemplary embodiments disclosed, various
advantages are accomplished by providing an impeller for a vacuum
cleaner comprising a lower plate in a shape of a disk; an upper
plate separated from the lower plate at a predetermined distance,
the upper plate having a diameter corresponding to the lower plate
and a central air inlet; and a plurality of air guide members
disposed radially between the lower plate and the upper plate, with
the plurality of air guide members chamfered at both corners at
their outside ends.
[0015] In an exemplary embodiment, the dimensions of the chamfered
corner satisfy the following formula: 1.5
mm.ltoreq.B.ltoreq.C/2
[0016] where B is the dimension of the chamfered corner measured in
the width direction of the air guide member and C is the width of
the air guide member.
[0017] Also, the plurality of air guide members may be attached to
the upper plate and the lower plate with cogging joints.
[0018] It is preferred that a dimension A of the chamfered corner
measured along the length of the air guide member is shorter than a
distance between an outside end of the air guide member and the
outermost cogging joint. Also, it is preferred that this dimension
A is between about 1.5 mm and about 3 mm.
[0019] In a further embodiment, an impeller for a vacuum cleaner
comprises a lower plate in a shape of a disk; a plurality of air
guide members disposed radially on the lower plate and having
chamfered corners at their outer ends; and an upper plate disposed
on the plurality of air guide members, the upper plate having a
central air inlet and a diameter corresponding to an inner
beginning point of the upper chamfers of the air guide members.
[0020] In further embodiments, a motor assembly for a vacuum
cleaner comprises a motor and an impeller, the impeller comprising:
a lower plate disposed at a motor shaft of the motor, the lower
plate in a shape of a disk, an upper plate separated from the lower
plate at a predetermined distance, the upper plate having a
diameter corresponding to the lower plate and a central air inlet,
and a plurality of air guide members disposed radially between the
lower plate and the upper plate, with their corners chamfered at
the outer ends thereof, and a diffuser disposed at an upper portion
of the motor, the diffuser guiding air drawn in from the impeller
toward the motor.
[0021] In exemplary embodiments, dimensions of the chamfered
corners are selected accoding to the following formula: 1.5
mm.ltoreq.B.ltoreq.C/2
[0022] where B is the dimension of the chamfered corner measured in
the width direction of the air guide member and C is the width of
the air guide member.
[0023] Also, the plurality of air guide members may be attached to
the upper plate and the lower plate with cogging joints.
[0024] It is preferred that a dimension A of the chamfered corner
measured along the length of the air guide member is shorter than a
distance between an outside end of the air guide member and the
outermost cogging joint. Also, it is preferred that this dimension
A is between about 1.5 mm and about 3 mm.
[0025] In a further embodiment, a motor assembly for a vacuum
cleaner comprises a motor and an impeller, the impeller comprising:
a lower plate disposed at a motor shaft of the motor, the lower
plate in a shape of a disk, a plurality of air guide members
disposed radially on the lower plate, the plurality of air guide
members chamfered at both outside corners thereof and an upper
plate disposed on the plurality of air guide members, the upper
plate having a diameter corresponding with a lengthwise beginning
point of the chamfered corner of the air guide member and a central
air inlet thereof; and a diffuser disposed at an upper portion of
the motor, the diffuser guiding air drawn in from the impeller
toward the motor.
[0026] Further embodiments provide a vacuum cleaner comprising a
suction brush, a dust collecting unit fluidly connected with the
suction brush and collecting dust, and a motor assembly fluidly
connected with the dust collecting unit and generating a suction
force. The motor assembly includes a motor; an impeller comprising:
a lower plate disposed at a motor shaft of the motor, the lower
plate in a shape of a disk, an upper plate separated from the lower
plate at a predetermined distance, the upper plate having a
diameter corresponding to the lower plate and a central air inlet,
and a plurality of air guide members disposed radially between the
lower plate and the upper plate, with their corners chamfered at
the outer ends thereof; and a diffuser disposed at an upper portion
of the motor, the diffuser guiding air drawn in from the impeller
toward the motor.
[0027] Tested embodiments of the impeller reduce peak overall noise
in the frequency range of 8.about.10 khz as compared with
conventional impellers.
[0028] A motor assembly incorporating the improved impeller
disclosed in various embodiments reduces overall noise and
particularly peak noise in the frequency range of 8.about.10 khz
relative to noise levels found in conventional devices.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0029] These and/or other aspects and advantages of the present
invention will become apparent and more readily appreciated from
the following description of the embodiments, taken in conjunction
with the accompanying drawing figures of which:
[0030] FIG. 1 is a cross sectional view illustrating a conventional
motor assembly;
[0031] FIG. 2 is a perspective view illustrating an impeller for a
vacuum cleaner used in the motor assembly shown in FIG. 1;
[0032] FIG. 3 is a plain view illustrating an impeller rotating
inside a diffuser;
[0033] FIG. 4 is a view illustrating noise sources of an impeller
as determined by a computer simulation analysis of an air flow;
[0034] FIG. 5 is a perspective view illustrating an impeller for a
vacuum cleaner according to a first exemplary embodiment of the
present invention;
[0035] FIG. 6 is a front view illustrating the impeller for the
vacuum cleaner shown in FIG. 5;
[0036] FIG. 7 is a view showing chamfering of an air guide member
of the impeller for the vacuum cleaner shown in FIG. 5;
[0037] FIG. 8 is a view illustrating a motor assembly having an
impeller according to the first embodiment of the present
invention;
[0038] FIG. 9 is a view illustrating an air guide member of a first
test impeller used for a noise comparative test;
[0039] FIG. 10 is a graphical illustration showing noise of the
first test impeller having the air guide member shown in FIG. 9 and
noise of an impeller according to the first embodiment of the
present invention;
[0040] FIG. 11 is a view illustrating an air guide member of a
second test impeller used for another noise comparative test;
[0041] FIG. 12 is a graphical illustration showing noise of the
second test impeller having the air guide member shown in FIG. 11
and noise of an impeller according to the first embodiment of the
present invention;
[0042] FIG. 13 is a perspective view illustrating an impeller for a
vacuum cleaner according to a second embodiment of the present
invention;
[0043] FIG. 14 is a partial front view illustrating the impeller
for the vacuum cleaner shown in FIG. 13;
[0044] FIG. 15 is a view illustrating a motor assembly having an
impeller according to the second embodiment of the present
invention;
[0045] FIG. 16 is a graphical illustration showing noise of the
conventional impeller and noise of an impeller according to the
second embodiment of the present invention; and
[0046] FIG. 17 is a view illustrating a vacuum cleaner having a
motor assembly according to an embodiment of the present
invention.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
[0047] In the following description, similar drawing reference
numerals may be used for the same elements even in different
drawings. The embodiments described, and their detailed
construction and elements, are merely provided to assist in a
comprehensive understanding of the invention. Thus, it is apparent
that the present invention can be carried out in a variety of ways,
and does not require any of the specific features described herein.
Also, well-known functions or constructions are not described in
detail since they would obscure the invention with unnecessary
detail.
[0048] A computer simulation analysis of noise sources was
performed to analyze the noise generated by a rotating impeller,
with the objective of reducing peak noise in the frequency range of
8.about.10 kHz. Results of this computer simulation analysis will
be described with reference to FIGS. 3 and 4.
[0049] Airflow in the impeller 20 was analyzed by computer
simulation of rotation of impeller 20 inside a diffuser 30 as shown
in FIG. 3. The analysis result is shown in FIG. 4. Referring to
FIG. 4, triangular tails 23b are respectively attached to outside
ends 23a of the plurality of air guide members 23. The triangular
tails 23b represent forces applied in the outside ends 23a of the
plurality of air guide members 23. This indicates that noise is
generated from outside ends 23a of the plurality of air guide
members 23 when the impeller 20 rotates. Accordingly, the inventors
have determined that an interaction between outside ends 23a of the
plurality of air guide members 23 of the impeller 20 and guide
members 31 of the diffuser 30 may generate noise when the impeller
20 rotates inside the diffuser 30 as shown in FIG. 3. In other
words, when the impeller 20 rotates, a major noise source may be
outside ends 23a of the plurality of air guide members 23.
[0050] In an exemplary embodiment, the shape of outside end 23a of
the air guide member 23 is changed, and the diameter of an upper
plate of the impeller 20 may also be modified, to reduce noise
arising from rotation of impeller 20, especially to reduce a noise
peak in the frequency range of 8.about.10 kHz.
[0051] Hereinafter, certain embodiments of the present invention
will be described in detail with reference to the accompanying
drawing figures.
[0052] Referring to FIGS. 5 and 6, an impeller 110 for a vacuum
cleaner according to a first embodiment of the present invention
has a lower plate 111, an upper plate 112 and a plurality of air
guide members 113.
[0053] The lower plate 111 is formed in the shape of a disk and a
center thereof is disposed at a motor shaft (not shown) of a motor.
The upper plate 112 is formed in the shape of a disk to correspond
with the lower plate 111 and has substantially the same diameter as
the lower plate 111. The upper plate 112 has a central air inlet
115. Also, it is preferred that the air inlet 115 is formed to
protrude from the upper plate 112 to a predetermined height. In the
embodiment shown, a connecting part 114 connecting the air inlet
115 with the upper plate 112 is formed as a curved surface having a
predetermined curvature to allow intake air to flow smoothly. The
plurality of air guide members 113 are disposed radially between
the lower plate 111 and the upper plate 112 at regular intervals.
Each of the air guide members 113 is formed in the shape of a bent
band having a predetermined curvature. Each of the air guide
members can be attached to the upper plate 112 and the lower plate
111 by various joining methods. In the present embodiment, each of
the air guide members is attached in the upper plate 112 and the
lower plate 111 with cogging joints 116. At this time, one end 113a
of the air guide member 113 toward the periphery of the lower plate
111 and of the upper plate 112 has both of its corners chamfered as
shown at 113c. It is preferred that chamfered corners 113c satisfy
the dimensional conditions described below.
[0054] FIG. 7 is a view showing details of chamfers on corners 113c
of the air guide member 113.
[0055] Referring to FIG. 7, It is preferred that a dimension A of
the chamfered corner, measured along the length of the air guide
member, is shorter than a distance between an outside end of the
air guide member and the outermost cogging joint. Dimension A will
be referenced herein as the "lengthwise dimension" of chamfered
corner 113. Also, it is preferred that this dimension A is between
about 1.5 mm and about 3 mm. Preferably, a length B of the air
guide member's widthwise direction of the chamfered corner 113c,
hereinafter referred to as a "widthwise dimension" of the chamfered
corner 113c, is so determined to satisfy Formula 1: 1.5
mm.ltoreq.B.ltoreq.C/2 <Formula 1> where, B is the widthwise
dimension of the chamfered corner 113c, and C is the width of air
guide member 113.
[0056] Also, the air guide member 113 has a length such that one
end 113a thereof is inside the peripheries of the lower plate 111
and of the upper plate 112 and the other end thereof is outside of
the air inlet 115 of the upper plate 112.
[0057] The operation of the impeller 110 for the vacuum cleaner
comprising the same structure as that described above will now be
described in more detail.
[0058] Referring to FIG. 8, a motor assembly 100 for the vacuum
cleaner having an impeller according to a first embodiment of the
present invention includes a motor 101, an impeller 110 rotated by
the motor 101 and a diffuser 120 guiding air drawn in by the
impeller 110 toward the motor 101.
[0059] Any of various types of motors operating at approximately
3,000 rpm to 3,600 rpm which are used generally in vacuum cleaners
may be used as the motor 101. In the present embodiment, a
universal motor operating at 3,000 rpm is used. However, this
example is not intended to limit the scope of the present
invention, as a wide variety of motors may be used for this
purpose.
[0060] The impeller 110 has a lower plate 111, an upper plate 112
and a plurality of air guide members 113. Referring to FIGS. 5 and
8, the lower plate 111 is formed in the shape of a disk and a
center thereof is disposed at a motor shaft 102 of a motor 101. The
upper plate 112 is formed in the shape of a disk to correspond with
the lower plate 111 and has substantially the same diameter as the
lower plate 111. The upper plate 112 has a centrally located air
inlet 115 for drawing in air. Also, the air inlet 115 is formed to
protrude from the upper plate 112 to a predetermined height. A
connecting part 114 connecting the air inlet 115 with the upper
plate 112 is formed as a curved surface having a predetermined
curvature to allow intake air to flow smoothly. The plurality of
air guide members 113 are disposed radially between the lower plate
111 and the upper plate 112 at regular intervals. Each of the air
guide members 113 is formed in the shape of a bent band having a
predetermined curvature. In the present embodiment, 9 air guide
members 113 are attached to the upper plate 112 and the lower plate
111 with cogging joints 116. At this time, one end 113a of the air
guide member 113 toward the periphery of the lower plate 111 and of
the upper plate 112 has both of its corners 113c chamfered. It is
preferred that the chamfered corners 113c satisfy the conditions
described above. In the present embodiment, if a width of the air
guide member 113 is C=7 mm, the widthwise dimension of the
chamfered portion is B=C/2=3.5 mm and the lengthwise dimension A is
3 mm. In this embodiment, the outermost of the cogging joints 116a,
116b is separated by over 3 mm from the outside end 113a of the air
guide member 113 (see FIG. 7).
[0061] The diffuser 120 is disposed at upper portion of the motor
101 in concentric circles outside the impeller 110. There is a gap
between the diffuser 120 and the impeller 110 to rotate the
impeller 110. The diffuser 20 has a plurality of guide members for
guiding air when the air is drawn in and discharged by the impeller
110 toward the motor 101. The diffuser 120 shown in FIGS. 3 and 8
is an exemplary diffuser that can be used in the motor assembly 100
for the vacuum cleaner, and one will appreciate that various types
of diffusers can be used.
[0062] The operation of the motor assembly 100 for the vacuum
cleaner comprising the same structure as that described above is
explained hereinafter.
[0063] When the motor shaft 102 of the motor assembly 100 rotates,
the lower plate 111 of the impeller 110 disposed at the motor shaft
102 is rotated, thereby rotating the impeller 110. When the
impeller 110 rotates, dust-laden air is drawn in through a dust
inlet of a suction brush (not shown) that is fluidly connected with
the air inlet 115 of the impeller upper plate 112. The dust and
impurities in the dust-laden air are removed while passing through
a dust-collecting unit (not shown), and accordingly, substantially
clean air enters into the air inlet 115 of the impeller 110. The
air entering air inlet 115 is scattered and enters inside ends of
the plurality of air guide members 113. The air passing into the
inside ends of the plurality of air guide members 113 is discharged
toward the diffuser 120 through outside ends 113a thereof.
[0064] In this embodiment, impeller peak noise in the frequency
range of 8.about.10 khz is reduced compared to devices having a
conventional impeller as shown in Table 1, FIGS. 10 and 12. In
other words, the peak noise of the impeller 110 according to the
first embodiment of the present invention is reduced by
approximately 9 dB compared to a first test impeller having the air
guide member 23 as shown FIG. 9, and by approximately 7.3 dB
compared to a second test impeller having the air guide member 23'
shown in FIG. 11. At FIGS. 10 and 12, thick curved lines 1 and 3
indicate respectively noise of the impeller according to the first
embodiment of the present invention and thin curved lines 2 and 4
indicate respectively noise of the first test impeller and the
second test impeller. TABLE-US-00001 TABLE 1 Impeller type
Electrical consumption (W) Noise (dB) First embodiment 875 75.3
First test impeller 896 86.3 Second test impeller 878 82.6
[0065] Both corners 113c of outside end 113a of the air guide
member 113 of the impeller 110 according to the first embodiment of
the present invention are chamfered. An exemplary chamfering
dimension of the chamfered corner 113c is A=3 mm, B=3.5 mm as
described above (see FIG. 7). Both corners 23d of an outside end of
the air guide member 23 of the fist test impeller form right angles
as shown in FIG. 9. An air guide member 23' of the second test
impeller has a groove 23a' with a predetermined radius at an
outside end thereof as shown in FIG. 11. The impeller 110 according
to the first embodiment of the present invention, the fast and
second test impellers have 8 or 9 air guide members. A universal
motor operating at 3,000 rpm is used for the test. The graphical
representation of generated noise in FIGS. 10 and 12 indicates a
peak noise level in the frequency range of 8.about.10 khz. The
frequency range of 8.about.10 khz generally includes a second BPF
(Blade Passage Frequency) of the impeller. Here, the BPF represents
the number of blades passing per second measured in cycles per
second (Hz). For example, when the speed of rotation of the motor
is 3000 rpm and the impeller has 9 air guide members, the BPF is
4,500 Hz. This frequency is referred to as a first-degree BPF. The
second-degree BPF is twice the first-degree BPF. In this example,
the second-degree BPF is 9,000 rpm.
[0066] The air discharged from the diffuser 120 cools the motor 101
and is discharged outside the vacuum cleaner through an outlet in
the main body (not shown).
[0067] Referring to FIGS. 13 and 14, an impeller 110' for a vacuum
cleaner according to a second embodiment of the present invention
has a lower plate 111, an upper plate 112' and a plurality of air
guide members 113.
[0068] The lower plate 111 is formed in the shape of a disk and a
center thereof is disposed at a motor shaft of a motor (not
shown).
[0069] The upper plate 112' is formed in the shape of a disk to
correspond with the lower plate 111 and has a shorter diameter than
that of the lower plate 111. The diameter of the upper plate 112'
is determined to correspond with a chamfering dimension of the air
guide member 113. It is preferred that the upper plate 112' has a
diameter such that an outside periphery 112a' of the upper plate
112' corresponds with a lengthwise beginning point 113s of
chamfered corner 113c of the air guide member 113. The upper plate
112' has an air inlet 115 drawing in the air in a center thereof
Also, the air inlet 115 is formed to protrude from the upper plate
112' to a predetermined height. And a connecting part 114'
connecting the air inlet 115 with the upper plate 112' is formed as
a curve surface having a predetermined curvature to allow the drawn
in air to flow smoothly.
[0070] The plurality of air guide members 113 are disposed radially
between the lower plate 111 and the upper plate 112' at regular
intervals. Each of the air guide members 113 is formed in the shape
of a bent band having a predetermined curvature. Each of the air
guide members 113 can be attached to upper plate 112' and lower
plate 111 with various types of jointing methods. In an exemplary
embodiment, each of the air guide members 113 is attached to the
upper plate 112' and the lower plate 111 with cogging joints 116.
In an embodiment, one end 113a of the air guide member 113 at the
periphery of the lower plate 111 and of the upper plate 112' has
chamfers at both corners 113c. The chamfering process will not be
explained hereinafter since it is similar to that of the air guide
member 113 of the impeller 110 according to a first embodiment of
the present invention as described above.
[0071] Referring to FIG. 14, a lengthwise dimension A of the
chamfered corner 113c is shorter than a distance between one end
113a of the air guide member 113 and the outermost joint 116a, 116b
among cogging joints 116 which attach the air guide member 113 to
the lower plate 111 and the upper plate 112'. Also, it is preferred
that the lengthwise dimension A of the chamfered corner 113c of the
air guide member 113 is between approximately 1.5 mm and 3 mm from
an original corner 113d thereof.
[0072] Also, the air guide member 113 preferably has a length such
that one end 113a thereof is inside the periphery of the lower
plate 111 and the other end thereof is outside of the air inlet 115
of the upper plate 112'.
[0073] The operation of the impeller 110' for the vacuum cleaner
comprising the same structure as that described above will not be
explained since it is similar to the operation of the impeller 110
of the first embodiment described above.
[0074] FIG. 15 is a sectional view illustrating a motor assembly
for the vacuum cleaner having an impeller 110' according to the
second embodiment of the present invention.
[0075] Referring to FIG. 15, a motor assembly 100' for the vacuum
cleaner having the impeller 110' according to the second embodiment
of the present invention includes a motor 101, an impeller 110'
rotated by the motor 101 and a diffuser 120 guiding intake air
drawn by the impeller 110' toward the motor 101.
[0076] Any of various types of motors having approximately between
3,000 rpm and 3,600 rpm which are used generally in vacuum cleaners
may be selected as the motor 101. In the present embodiment, a
universal motor having 3,000 rpm is used. However, the scope of the
invention is not limited to any particular motor 101.
[0077] The impeller 110' has a lower plate 111, an upper plate 112'
and a plurality of air guide members 113. Referring to FIGS. 13 and
14, the lower plate 111 is formed in the shape of a disk and a
center thereof is disposed at a motor shaft 102 of the motor 101.
The upper plate 112' is formed in the shape of a disk to correspond
with the lower plate 111 and has a diameter to correspond with
beginning points 113s of the chamfered corner 113c of a plurality
of air guide members 113. The upper plate 112' has a central air
inlet 115 for drawing intake air. Also, the air inlet 115 is formed
to protrude from the upper plate 112' to a predetermined height. A
connecting part 114' connecting the air inlet 115 with the upper
plate 112' is formed as a curved surface having a predetermined
curvature to allow the intake air to flow smoothly. A plurality of
air guide members 113 are disposed radially between the lower plate
111 and upper plate 112' at regular intervals. Each of the air
guide members 113 is formed in the shape of a bent band having a
predetermined curvature. In the present embodiment, 9 air guide
members are attached to the upper plate 112' and the lower plate
111 with cogging joints 116. At an end 113a of the air guide member
113 nearest the periphery of lower plate 111 and upper plate 112',
both corners 113c are chamfered. It is preferred that the chamfered
corners 113c are formed to satisfy the conditions described above.
In the present embodiment, if a width C of the air guide member 113
is approximately 7 mm, the widthwise dimension B of the chamfering
corner 113c is B=C/2=3.5 mm and the lengthwise dimension A thereof
is approximately 3 mm. In an embodiment, the outermost cogging
joint 116a, 116b is spaced apart by 3 mm or more from the outside
end 113a of the air guide member 113 (see FIG. 14).
[0078] The diffuser 120 is disposed at an upper portion of the
motor 101 in concentric circles outside the impeller 110'. There is
a gap between the diffuser 120 and the impeller 110' to rotate the
impeller 110'. The diffuser 120 has a plurality of guide members
for guiding air, when the air is drawn in and discharged by the
impeller 110' toward the motor 101. The diffuser 120 shown in FIG.
15 is an example of a diffuser that can be used in the motor
assembly 100' for the vacuum cleaner according to the present
invention. Various types of diffusers can also be used in the motor
assembly 100'.
[0079] The operation of the motor assembly 100' for the vacuum
cleaner having the impeller 110' according to the second embodiment
of the present invention comprising the same structure as that
described above will not be explained in further detail, since it
is similar to that of the motor assembly 100 having the impeller
110 according to the first embodiment of the present invention
described above.
[0080] In the embodiment shown, peak impeller noise in the
frequency range of approximately 8.about.10 khz of the motor
assembly 100' having an impeller 110' according to the second
embodiment of the present invention is significantly reduced,
compared to a motor assembly having a conventional impeller as
shown in Table 2 and FIG. 16. Peak noise generated by the impeller
110' according to the second embodiment of the present invention is
reduced by approximately 6.5 dB compared to the conventional
impeller. At FIG. 16, a thick line 5 indicates noise of the
impeller 110' according to the second embodiment of the present
invention and a thin line 6 indicates noise of the conventional
impeller. Also, overall noise that averages noise in frequency of
total range is reduced by approximately 1.6 dBA. TABLE-US-00002
TABLE 2 Impeller type Overall noise (dBA) Peak noise 8.about.10 khz
(dB) Second Embodiment 93.4 83.4 Conventional 94.9 89.9
[0081] Both corners 13c of outside end 113a of the air guide member
113 of the impeller 110' according to the second embodiment of the
present invention are chamfered. Dimensions of chamfered corners
113c are A=3 mm and B=3.5 mm as described above. The upper plate
112' of the impeller 110' has a diameter corresponding to the
beginning points 113s of the chamfered corners 113c of air guide
members 113 (see FIG. 14). Impeller 20 according to the
conventional art has a plurality of air guide members 23 having
right angles at corners 23d of their outside ends as shown FIG. 9.
The impeller 110' according to the second embodiment of the present
invention and the conventional impeller 20 respectively have 8 or 9
air guide members. A universal motor operating at 3,000 rpm is used
for the noise test. The term "overall noise" refers to average
noise in the total frequency range. The "peak noise" in the range
of approximately 8.about.10 khz refers to a noise having a peak
value in frequency of 8.about.10 khz. The frequency range of
8.about.10 khz generally includes a second BPF (Blade Passage
Frequency) of the impeller. The BPF represents the number of blades
passing per a second measured in cycles per second (Hz). For
example, when the motor rotates at 3000 rpm and the impeller has 9
air guide members, the BPF is 4,500 Hz. This is called as a
first-degree BPF. The second-degree BPF is twice the first-degree
BPF. In the present embodiment, the second-degree BPF is
approximately 9,000 rpm.
[0082] FIG. 17 is a view illustrating a vacuum cleaner having the
motor assembly 100 having an impeller 110 according to the first
embodiment of the present invention.
[0083] Referring to FIG. 17, the vacuum cleaner 200 according to
the present invention includes a suction brush 210 that draws in
dust and impurities, an extension pipe 220 fluidly connecting
between the suction brush 210 and a main body 230, and the main
body 230 that is partitioned into a dust collecting portion (not
shown) and a motor portion 231.
[0084] The suction brush 210 has a dust inlet (not shown), which
draws in dust and impurities at the bottom thereof A
dust-collecting unit (not shown), which separates and collects dust
and impurities from the dust-laden air drawn in through the suction
brush 210, is disposed at the dust collecting portion (not shown).
For example, a dust bag or cyclone dust collecting unit may be used
as the dust-collecting unit. A motor assembly 100, which generates
a suction force drawing in dust and impurities through the suction
brush 210, is disposed within the motor portion 231. The motor
assembly 100 has a motor 101, an impeller 110 (see FIG. 8) rotated
by the motor 101 and a diffuser 120 guiding air drawn in by the
impeller 110 toward the motor 101. The impeller 110 has a plurality
of air guide members 113. An outside end 113a of the air guide
member 113 thereof has chamfered corners 113c. Since the motor
assembly 100 is similar to that described above, a detailed
explanation will be omitted.
[0085] When the vacuum cleaner 200 is turned on for cleaning
operations according to the present invention, the motor 101
located in motor portion 231 starts rotating. When the motor 101
rotates, the impeller 110 disposed at an end of the motor shaft 102
rotates. When the impeller 110 rotates, dust-laden air is drawn in
through the dust inlet of the suction brush 210. The dust and
impurities contained in the dust-laden air are removed while
passing through the dust-collecting unit located in the dust
collecting portion, and as a result, the dust-laden air is cleaned.
The cleaned air enters into the air inlet 115 of the impeller 110,
passes outside ends 113a of a plurality of air guide members 113
and enters into the diffuser 120 (see FIGS. 7 and 8). At this time,
since both corners 113c of the plurality of air guide members 113
are chamfered, peak noise in the frequency range of 8.about.10 khz
is reduced. The air entering the diffuser 120 passes through the
motor 101 and is discharged outside the main body 230 of the vacuum
cleaner 200 through an outlet 233.
[0086] Since structure and operation of a vacuum cleaner having a
motor assembly 100' with an impeller 110' according to the second
embodiment of the present invention are similar to those of a
vacuum cleaner having an impeller 110 according to the first
embodiment described above, a detailed explanation thereof will be
omitted.
[0087] 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.
* * * * *