U.S. patent application number 10/512875 was filed with the patent office on 2005-10-06 for drum type washing machine.
Invention is credited to Lee, Deug Hee, Lee, Tae Hee.
Application Number | 20050217323 10/512875 |
Document ID | / |
Family ID | 32866901 |
Filed Date | 2005-10-06 |
United States Patent
Application |
20050217323 |
Kind Code |
A1 |
Lee, Deug Hee ; et
al. |
October 6, 2005 |
Drum type washing machine
Abstract
The present invention relates to a drum type washing machine for
smooth attenuation of different directions of vibration
transmissive to a tub during rotation of the drum. The present
invention provides a drum type washing machine including a cabinet
having an opening in a front surface, a tub inside of the cabinet
having a drum rotatably mounted on an inside thereof, first, and
second dampers connected between one side of a circumferential
surface of the tub and the cabinet respectively, a third damper
connected between the other side of the circumferential surface of
the tub and the cabinet, and at least one spring connected between
the circumferential surface of the tub and the cabinet. The at
least one spring includes a first spring connected to an upper
surface of the tub on a side the same with the first, and second
dampers for attenuating up/down, and left/right vibrations of the
tub, and second, and third springs connected to the upper surface
of the tub on a side the same with the third damper for attenuating
up/down, left/right, and front/rear vibrations of the tub.
Inventors: |
Lee, Deug Hee;
(Gyeongsangnam-do, KR) ; Lee, Tae Hee; (Seoul,
KR) |
Correspondence
Address: |
MCKENNA LONG & ALDRIDGE LLP
1900 K STREET, NW
WASHINGTON
DC
20006
US
|
Family ID: |
32866901 |
Appl. No.: |
10/512875 |
Filed: |
October 29, 2004 |
PCT Filed: |
February 17, 2004 |
PCT NO: |
PCT/KR04/00313 |
Current U.S.
Class: |
68/23.1 ; 68/139;
68/23.3 |
Current CPC
Class: |
D06F 37/20 20130101;
D06F 37/22 20130101 |
Class at
Publication: |
068/023.1 ;
068/023.3; 068/139 |
International
Class: |
D06F 037/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 17, 2003 |
KR |
10-2003-0009804 |
Claims
What is claimed is:
1. A drum type washing machine comprising: a cabinet having an
opening in a front surface; a tub inside of the cabinet having a
drum rotatably mounted on an inside thereof; first, and second
dampers connected between one side of a circumferential surface of
the tub and the cabinet, respectively; a third damper connected
between the other side of the circumferential surface of the tub
and the cabinet; and at least one spring connected between the
circumferential surface of the tub and the cabinet.
2. The drum type washing machine as claimed in claim 1, wherein at
least one of the first to third dampers is connected to a lower
surface of the tub.
3. The drum type washing machine as claimed in claim 1, wherein the
first, and second dampers are arranged adjacent to a front part,
and a rear part in a longitudinal direction of the tub,
respectively.
4. The drum type washing machine as claimed in claim 1 or 3,
wherein the third damper is arranged at middle in a longitudinal
direction of the tub.
5. The drum type washing machine as claimed in claim 1 or 3,
wherein the third damper is arranged at a position opposite to
middle of the first and second dampers.
6. The drum type washing machine as claimed in claim 1, wherein the
first, and second dampers are positioned on a side the drum rotates
from an upper side to a lower side when the tub is seen from the
front.
7. The drum type washing machine as claimed in claim 1 or 6,
wherein the third damper is positioned on a side the drum rotates
from a lower side to an upper side when the tub is seen from the
front.
8. The drum type washing machine as claimed in claim 1 or 6,
wherein the first or second damper has a half of a damping
capability of the third damper.
9. The drum type washing machine as claimed in claim 1, wherein the
at least one spring includes; a first spring connected to an upper
surface of the tub on a side the same with the first, and second
dampers, and second, and third springs connected to the upper
surface of the tub on a side the same with the third damper.
10. The drum type washing machine as claimed in claim 9, wherein
the first spring is positioned at middle in a longitudinal
direction of the tub.
11. The drum type washing machine as claimed in claim 9 or 10,
wherein the second, and third springs are arranged adjacent to a
front part, and a rear part in the longitudinal direction of the
tub, respectively.
12. The drum type washing machine as claimed in claim 9 or 10,
wherein the first spring is arranged at a point opposite to middle
of the second, and third springs.
13. The drum type washing machine as claimed in claim 9, wherein
the first spring is positioned on a side the drum rotates from an
upper side to a lower side when the tub is seen from the front.
14. The drum type washing machine as claimed in claim 9 or 13,
wherein the second, and third springs are positioned on a side the
drum rotates from a lower side to an upper side when the tub is
seen from the front.
15. The drum type washing machine as claimed in claim 9 or 13,
wherein the second, or third spring has a half of damping
capability of the first spring.
16. A drum type washing machine comprising: a cabinet having an
opening in a front surface; a tub inside of the cabinet having a
drum rotatably mounted on an inside thereof; first, and second
dampers connected between one side of a circumferential surface of
the tub and the cabinet respectively, for attenuating up/down,
left/right, and front/rear vibrations of the tub; a third damper
connected between the other side of the circumferential surface of
the tub and the cabinet, for attenuating up/down, and left/right
vibrations of the tub; a first spring connected between a side of a
circumferential surface of the tub the same with the first, and
second dampers and the cabinet, for attenuating up/down, and
left/right vibrations of the tub; and second, and third springs
connected between a side of a circumferential surface of the tub
the same with the third damper and the cabinet respectively, for
attenuating up/down, left/right, and front/rear vibrations of the
tub.
17. The drum type washing machine as claimed in claim 16, wherein
at least one of the first to third dampers is connected to a lower
surface of the tub, and at least one of the first to third springs
is connected to an upper surface of the tub.
18. The drum type washing machine as claimed in claim 16, wherein
the first and second dampers are arranged adjacent to a front part
and a rear part in a longitudinal direction of the tub
respectively, and the third damper is arranged at middle in a
longitudinal direction of the tub.
19. The drum type washing machine as claimed in claim 16, wherein
the first, and second dampers are positioned on a side the drum
rotates from an upper side to a lower side when the tub is seen
from the front, and the third damper is positioned on a side the
drum rotates from a lower side to an upper side when the tub is
seen from the front.
20. The drum type washing machine as claimed in claim 16 or 19,
wherein the first or second damper has a half of damping capability
of the third damper.
21. The drum type washing machine as claimed in claim 16, wherein
the first spring is arranged at middle in a longitudinal direction
of the tub, and the second, and third springs are arranged adjacent
to a front part and a rear part in a longitudinal direction of the
tub.
22. The drum type washing machine as claimed in claim 16, wherein
the first spring is positioned on a side the drum rotates from an
upper side to a lower side when the tub is seen from the front, and
the second, third springs are positioned on a side the drum rotates
from a lower side to an upper side when the tub is seen from the
front.
23. The drum type washing machine as claimed in claim 16 or 22,
wherein the second, or third spring has a half of damping
capability of the first spring.
24. A drum type washing machine comprising: a cabinet having an
opening in a front surface; a tub inside of the cabinet having a
drum rotatably mounted on an inside thereof; first, and second
dampers connected between one side of a lower surface of the tub
and the cabinet respectively, for attenuating up/down, left/right,
and front/rear vibrations of the tub; a third damper connected
between a side of the lower surface of the tub opposite to the
first and the second dampers and the cabinet, for attenuating
up/down, and left/right vibrations of the tub; and at least one
spring connected between the circumferential surface of the tub and
the cabinet, for attenuating up/down, left/right, and front/rear
vibrations of the tub.
25. The drum type washing machine as claimed in claim 24, wherein
the at least one spring includes; a first spring connected to an
upper surface of the tub on a side the same with the first, and
second dampers for attenuating up/down, and left/right vibrations
of the tub, and second, and third springs connected to the upper
surface of the tub on a side the same with the third damper for
attenuating up/down, left/right, and front/rear vibrations of the
tub.
Description
TECHNICAL FIELD
[0001] The present invention relates to washing machines, and more
particularly, to a drum type washing machine, in which a device,
which attenuates vibration transmissive to a tub when a drum
rotates and washes laundry, is improved.
BACKGROUND ART
[0002] The washing machine progresses washing, rinsing, and
spinning processes for removing contaminants stuck to laundry by
using actions of detergent and water. There are pulsator type
washing machines in which a washing tub is stands vertical, and
drum type washing machines in which a rotating drum is mounted in a
horizontal direction.
[0003] The pulsator type washing machine washes by using a friction
force between a water circulation taken place when the pulsator
mounted on a bottom of the washing tub rotates and the laundry.
Even though the pulsator type washing machine is advantageous in
that a washing time period is short, a washing machine that can
handle a large capacity can be fabricated, and price is low, but is
disadvantageous in that laundry is liable to entangle, and damage
to the laundry is relatively high.
[0004] On the other hand, the drum type washing machine washes by
using impact and friction taken place at the time the laundry
lifted by tumbling ribs on an inside surface of the drum drops down
when the drum rotates. Since the drum type washing machine is
advantageous in that there is almost no damage to the laundry, and
entangle of laundry, and a small amount of water is used, the
supply of the drum type washing machine increases sharply,
recently.
[0005] FIGS. 1 and 2 illustrates related art drum type washing
machines, referring to which the drum type washing machine will be
described in more detail.
[0006] Referring to FIG. 1, there is an introduction opening 11 in
a front surface of a cabinet 10 that forms an outer appearance of
the drum type washing machine, with a door 15 on the opening 11 for
opening/closing the opening 11. There is a tub inside of the
cabinet provided in a floated state. For this, as shown in FIG. 2,
one pair of springs 51 are connected between opposite side parts of
an upper surface of the tub 20 and the cabinet 10, and one pair of
damper 55 are connected between opposite side parts of a lower
surface of the tub 20 and the cabinet 10.
[0007] There is a drum 30 rotatably mounted inside of the tub 20
having a plurality of tumbling ribs (not shown) projected from an
inside surface. For this, a belt 45 is connected between a motor 41
below the tub 20 and the drum 30. However, a structure of the drum
type washing machine is not limited to this, but the motor may be
directly connected to the drum 30 without the belt 45.
[0008] In the drum type washing machine, when laundry is introduced
into the drum 30, and the drum 30 is rotated, the laundry is lifted
up by the tumbling ribs, and drops down. The impact and the
friction taken place in the time washes the laundry.
[0009] However, when the drum 30 rotates for washing or waster
extraction, the tub 20 has much vibration transmitted thereto.
Particularly, during spinning when the drum 30 spins at a high
speed, the vibration transmitted to the tub 20 becomes greater if
the laundry leans to one side of the drum 30.
[0010] Meanwhile, the vibration taken place thus is attenuated with
the one pair of springs 51 and the dampers 55 that support the tub
20. However, because the one pair of the springs 51 and dampers 55
are connected to the tub 20 at a middle of a longitudinal direction
of the tub 20 substantially, it is difficult that the one pair of
the springs 51 and dampers 55 attenuate all the front/rear
direction vibration, up/down direction vibration, and left/right
direction vibration, of the tub 20, smoothly.
[0011] Consequently, there can not, but be a comparative heavy
vibration at the related art drum type washing machine, to cause a
problem of generation of a loud noise.
DISCLOSURE OF INVENTION
[0012] An object of the present invention devised to solve the
problem lies on attenuating various directions of vibrations
transmissive to a tub when the washing machine is in operation,
smoothly.
[0013] The object of the present invention can be achieved by
providing a drum type washing machine including a cabinet having an
opening in a front surface, a tub inside of the cabinet having a
drum rotatably mounted on an inside thereof, first, and second
dampers connected between one side of a circumferential surface of
the tub and the cabinet respectively, a third damper connected
between the other side of the circumferential surface of the tub
and the cabinet, and at least one spring connected between the
circumferential surface of the tub and the cabinet.
[0014] At least one of the first to third dampers is connected to a
lower surface of the tub.
[0015] The first, and second dampers are arranged adjacent to a
front part, and a rear part in a longitudinal direction of the tub
respectively, and the third damper is arranged at middle in a
longitudinal direction of the tub, or at a position opposite to
middle of the first and second dampers.
[0016] The first, and second dampers are positioned on a side the
drum rotates from an upper side to a lower side when the tub is
seen from the front, and the third damper is positioned on a side
the drum rotates from a lower side to an upper side when the tub is
seen from the front.
[0017] The first or second damper has a half of a damping
capability of the third damper, substantially.
[0018] The at least one spring includes a first spring connected to
an upper surface of the tub on a side the same with the first, and
second dampers, and second, and third springs connected to the
upper surface of the tub on a side the same with the third
damper.
[0019] The first spring is positioned at middle in a longitudinal
direction of the tub, the second, and third springs are arranged
adjacent to a front part, and a rear part in the longitudinal
direction of the tub respectively. Of course, the first spring is
arranged at a point opposite to middle of the second, and third
springs.
[0020] The first spring is positioned on a side the drum rotates
from an upper side to a lower side when the tub is seen from the
front, and the second, and third springs are positioned on a side
the drum rotates from a lower side to an upper side when the tub is
seen from the front.
[0021] The second, or third spring has a half of damping capability
of the first spring.
[0022] Thus, the present invention can attenuate not only
left/right, and up/down vibrations, but also front/rear vibration
transmissive to the tub during rotation of the drum by using a
small number of dampers and springs, effectively.
BRIEF DESCRIPTION OF DRAWINGS
[0023] The accompanying drawings, which are included to provide a
further understanding of the invention, illustrate embodiments of
the invention and together with the description serve to explain
the principle of the invention.
[0024] In the drawings;
[0025] FIG. 1 illustrates a section of a related art drum type
washing machine;
[0026] FIG. 2 illustrates a section across a line I-I in FIG.
1;
[0027] FIG. 3 illustrates a section of a washing machine in
accordance with a preferred embodiment of the present
invention;
[0028] FIG. 4 illustrates a perspective view showing dampers and
springs connected to a tub in the washing machine in FIG. 3;
and
[0029] FIGS. 5A.about.5E illustrate graphs showing comparison of
vibration amplitudes measured at different parts of tubs of the
related art and the present invention, respectively; wherein
[0030] FIG. 5A illustrates a graph showing comparison of front/rear
direction vibration amplitudes at a lower part of the tub,
[0031] FIG. 5B illustrates a graph showing comparison of up/down
direction vibration amplitudes at a front part of the tub,
[0032] FIG. 5C illustrates a graph showing comparison of left/right
direction vibration amplitudes at a front part of the tub,
[0033] FIG. 5D illustrates a graph showing comparison of vibration
amplitudes at a front part of the tub caused by yawing, and
[0034] FIG. 5E illustrates a graph showing comparison of vibration
amplitudes at a rear part of the tub caused by yawing.
BEST MODE FOR CARRYING OUT THE INVENTION
[0035] Reference will now be made in detail to the preferred
embodiments of the present invention, examples of which are
illustrated in the accompanying drawings.
[0036] In describing the embodiments, same parts will be given the
same names and reference symbols, and additional, and repetitive
description of which will be omitted.
[0037] Referring to FIG. 3, there are a tub 200 inside of a cabinet
100 having an opening 100 in a front surface, and a drum 300
rotatably mounted on an inside of the tub 200. Since this structure
is similar to the related art drum type washing machine described
with reference to FIG. 1, the description will be omitted, and only
springs and dampers which elastically support the tub 200 inside of
the cabinet 100 will be described in detail.
[0038] The tub 200 of the present invention is supported with three
dampers 410, 420, and 430. Each of the three dampers 410, 420, and
430 has one end connected to a circumferential surface of the tub
200, and the other end connected to the cabinet 100.
[0039] Of the dampers 410, 420, and 430, two dampers are connected
to one side of the circumferential surface of the tub 200. For
reference, FIGS. 3 and 4 illustrate an example in which, when the
tub 200 is seen from the front, the first damper 410, and the
second damper 420 are connected to one side with respect to a
vertical plane passing through an axis of the tub 200.
[0040] Of the dampers 410, 420, and 430, the other damper is
connected to the other side of the circumferential surface of the
tub 200. For reference, FIGS. 3 and 4 illustrate an example in
which, when the tub 200 is seen from the front, the third damper
430 is connected to the other side with respect to the vertical
plane passing through the axis of the tub 200.
[0041] In this instance, as shown in FIG. 4, at least one, or more
than one, preferably all of the first, to third dampers 410, 420,
and 430 are connected to a lower surface of the tub 200.
[0042] Meanwhile, one of the two dampers connected to the same side
of the circumferential surface of the tub 200 is arranged adjacent
to a front part of the tub 200 with reference to a longitudinal
middle point of the tub 200, and the other one adjacent to a rear
part of the tub 200. For reference, FIGS. 3 and 4 illustrate an
example in which the first damper 410 is arranged adjacent to the
front part of the tub 200, and the second damper 420 is arranged
adjacent to the rear part of the tub 200.
[0043] Opposite to this, the other damper, for an example, the
third damper 430 is arranged at the middle part in the longitudinal
direction of the tub 200, or at a point opposite to a middle point
of the first damper 410 and the second damper 420.
[0044] In the meantime, in arranging the three dampers 410, 420,
and 430, it is good practice even to take a rotation direction of
the drum 300 into account. Because, there is a force for rotating
the tub 200 in a direction the drum 300 rotates.
[0045] Taking this into account, it is preferable that the two
dampers, i.e., the first damper 410 and the second damper 420 are
arranged on a side the drum 300 rotates from an upper side to a
lower side when the tub 200 is seen from the front. Opposite to
this, it is preferable that the other one damper, i.e., the third
damper 430 is arranged on a side the drum 300 rotates from a lower
side to an upper side when the tub 200 is seen from the front.
[0046] It is preferable that a damping capability of the two
dampers, i.e., the first damper 410, and the second damper 420 is
substantially a half of the damping capability of the other damper,
i.e., the third damper 430. Such a system balances sums of damping
capabilities that support left and right sides of the tub 200.
Moreover, the low damping capabilities of the first damper 410 and
the second damper 420 can attenuate even a light vibration.
[0047] In the meantime, a greater number of dampers than the three
dampers 410, 420, and 430 may be provided, for attenuating the
vibration of the tub 200 taken place when the drum 300 rotates.
[0048] However, in this case, an obtainable vibration damping
effect is low compared to the number of dampers provided thereto.
That is, a vibration damping effect that can adequately offset a
cost for additional dampers is not obtainable.
[0049] Moreover, the excessive damping capability from the many
number of dampers makes unable to attenuate light vibrations
transmissive to the tub 200, such that the washing machine fails in
carrying out smooth washing.
[0050] Thus, if the washing machine is fabricated, taking the
number of dampers, positions of mounting of the dampers, and the
damping capabilities of respective dampers the present invention
suggests into account, a maximum damping effect is obtainable while
a minimum number of dampers are used.
[0051] In the meantime, besides the dampers 410, 420, and 430
connected thus, the washing machine of the present invention is
further provided with at least one spring connected between a
circumferential surface of the tub 200 and the cabinet 100 for
attenuating the vibration of the tub 200, which will be described
in more detail.
[0052] In the washing machine of the present invention, alike the
dampers 410, 420, and 430, it is preferable that three springs are
provided thereto.
[0053] Any one of the three springs 510, 520, and 530, for an
example, a first spring 510 is connected to a side of the
circumferential surface of the tub 200 the same with the side of
the first damper 410 and the second damper 420.
[0054] The other two of the three springs 510, 520, and 530, for an
example, the second spring 520, and the third spring 530 are
connected to a side of the circumferential surface of the tub 200
the same with the side of the third damper 430.
[0055] Referring to FIG. 3, it is preferable that at least one,
preferably all of the first to third springs 510, 520, and 530 are
connected to an upper surface of the circumferential surface of the
tub 200.
[0056] Meanwhile, the first spring 510 is arranged at a middle of a
longitudinal direction of the tub 200, and one of the second and
third springs 520, and 530 is arranged adjacent to a front with
reference to the middle point of the longitudinal direction of the
tub 200, and the other one is arranged adjacent to a rear with
reference to the middle point of the longitudinal direction of the
tub 200.
[0057] For reference, FIGS. 3 and 4 illustrate an example in which
the second spring 520 is arranged in a front part of a longitudinal
direction of the tub 200, and the third spring 530 is arranged in a
rear part of the longitudinal direction of the tub 200. In the
meantime, the first spring 510 may be connected to a point opposite
to a middle point of the second, and third springs 520, and
530.
[0058] Also, in arranging the three springs 510, 520, and 530, it
is good practice to take the rotation direction of the drum 300
into account. Therefore, if the rotation direction of the drum 300
is taken into account, it is preferable that the first spring 510
is positioned on a side the drum rotates from an upper side to a
lower side when the tub 200 is seen from the front, and the second,
and third springs 520, and 530 are positioned on a side the drum
rotates from a lower side to an upper side when the tub 200 is seen
from the front.
[0059] Moreover, it is preferable that damping capabilities of the
second, and third springs 520, and 530 are a half of the damping
capability of the first spring 510. This system balances sums of
the damping forces that support left/right sides of the tub 200,
and able to attenuate low vibration with the second and third
spring 520, and 530 which have low damping forces.
[0060] A process of damping the vibration acting on the tub 200
when the washing machine of the present invention is in operation
will be described.
[0061] In this instance, the first damper 410 and the second damper
420 uniformly attenuate vibration acting on the tub 200 in the
rotation direction of the drum 300, vibration acting on the tub 200
in the left/right directions of the drum 300, and vibration acting
on the tub 200 in the front/rear directions of the drum 300 at
positions in a front part, and a rear part of the tub 200,
respectively. Of course, the vibration acting in up/down directions
is also attenuated by the first damper 410 and the second damper
420.
[0062] Moreover, because the first damper 410, or the second damper
420 has a damping force substantially a half of the third damper
430, even low vibration acting on the tub 200 is attenuated by the
first damper 410 and the second damper 420. According to this,
transmission of vibration to other parts caused by an excessive
damping force can be prevented, enabling smooth attenuation of the
vibration acting on the tub 200.
[0063] The third damper 430 attenuates the vibration acting on the
tub 200 along a direction of rotation of the drum 300, and the
vibration acting in up/down directions of the tub 200.
[0064] On the other hand, the first to third springs 510, 520, and
530 also attenuate the vibration of the tub 200, together with the
first to third dampers 410, 420, and 430.
[0065] In this instance, the first spring 510 attenuates the
up/down vibration of the tub 200, the vibration acting on the tub
200 along the rotation direction of the drum 300, and the
left/right vibration.
[0066] The second spring 520 and the third spring 530 attenuate the
vibration acting in up/down, and left/right directions of the tub
200, the vibration acting on the tub 200 in the rotation direction
of the drum 300, and the vibration acting front/rear direction of
the tub 200.
[0067] In the meantime, because the second spring 520, or the third
spring 530 also has a damping capability substantially a half of
the damping capability of the first spring 510, even low vibration
transmissive to the tub 200 can be attenuated, thereby providing a
great vibration attenuating effect.
[0068] In the washing machine of the present invention, the
vibrations acting in up/down directions, left/right directions, and
front/rear directions of the tub 200 are attenuated significantly
in comparison to the related art that uses two dampers and springs.
This can be confirmed with results of experiments illustrated in
FIGS. 5A to 5E easily, which will be described.
[0069] FIG. 5A illustrates a graph showing comparison of vibration
amplitudes at a lower part of the tub caused by translation of the
tub. As shown, it can be noted that, while the related art drum
type washing machine has a 70 mm vibration amplitude of the tub in
front/rear directions, the drum type washing machine of the present
invention has an 18 mm vibration amplitude of the tub in front/rear
directions. Thus, the present invention reduces the vibration
amplitude in a range of approx. 50 mm at the lower part of the tub
caused by front/rear direction translation of the tub.
[0070] FIG. 5B illustrates a graph showing comparison of up/down
direction vibration amplitudes at a front part of the tub. For
reference, the tub vibrates in up/down directions due to pitching
and up/down direction translation. As shown in FIG. 5B, it can be
noted that, while the up/down direction amplitude of the tub of the
related art drum type washing machine is in a range of approx. 35
mm at the front part of the tub, the up/down direction amplitude of
the tub of the present invention drum type washing machine is in a
range of approx. 9 mm at the front part of the tub. Thus, the
present invention reduces the up/down direction vibration amplitude
in a range of approx. 24 mm at the front part of the tub 200.
[0071] FIG. 5C illustrates a graph showing comparison of left/right
direction vibration amplitudes at a front part of the tub. For
reference, the tub vibrates in left/right directions due to yawing
and left/right direction translation. As shown in FIG. 5C, it can
be noted that, while the left/right direction amplitude of the tub
of the related art drum type washing machine is in a range of
approx. 23 mm at the front part of the tub, the left/right
direction amplitude of the tub of the present invention drum type
washing machine is in a range of approx. 19 mm at the front part of
the tub. Thus, the present invention reduces the left/right
direction vibration amplitude in a range of approx. 4 mm at the
front part of the tub.
[0072] Next, FIGS. 5D and 5E illustrate graphs comparing vibration
amplitudes at a front part, and a rear part of the tub caused by
yawing, respectively. For reference, since vibration amplitudes
caused by left/right direction translation of the tub is excluded,
smaller values are measured than the values measured in experiments
of FIGS. 5A to 5C.
[0073] Referring to FIG. 5D, it can be noted that, while the yawing
amplitude of the tub of the related art drum type washing machine
is in a range of approx. 12.5 mm at the front part of the tub, the
yawing amplitude of the tub 200 of the present invention drum type
washing machine is in a range of approx. 11.5 mm at the front part
of the tub. Thus, the present invention reduces the yawing
vibration amplitude in a range of approx. 1 mm at the front part of
the tub.
[0074] Referring to FIG. 5E, it can be noted that, while the yawing
amplitude of the tub of the related art drum type washing machine
is in a range of approx. 13.4 mm at the rear part of the tub, the
yawing amplitude of the tub of the present invention drum type
washing machine is in a range of approx. 13 mm at the rear part of
the tub. Thus, the present invention reduces the yawing vibration
amplitude in a range of approx. 0.4 mm at the rear part of the
tub.
[0075] Thus, the present invention attenuates the front/rear
direction vibration of the tub 200 and the up/down direction
vibration, significantly. Though smaller than the front/rear
direction, and the up/down direction vibration reduction, the
left/right direction vibration of the tub 200 is also reduced.
Therefore, the present invention reduces the vibration of the tub
very smoothly, to reduce noise, significantly.
[0076] It will be apparent to those skilled in the art that various
modifications and variations can be made in the present invention
without departing from the spirit or scope of the invention. Thus,
it is intended that the present invention cover the modifications
and variations of this invention provided they come within the
scope of the appended claims and their equivalents.
INDUSTRIAL APPLICABILITY
[0077] The present invention provides a number, and fitting
positions of dampers, and a number, and fitting positions of
springs that can give the highest vibration reduction efficiency
with the lowest cost in reduction of vibration acting on the tub
during operation of the washing machine.
[0078] Therefore, the present invention permits effective reduction
of various vibration acting on a tub in various directions during
operation of the washing machine. Therefore, the washing, ringing,
and spinning can be carried out in a state the washing machine is
stable. Moreover, noise caused by the vibration can be reduced,
significantly.
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