U.S. patent application number 14/796631 was filed with the patent office on 2016-01-14 for washing machine.
The applicant listed for this patent is LG ELECTRONICS INC.. Invention is credited to Youngjong KIM, Youngjun KIM, Insik Yu.
Application Number | 20160010261 14/796631 |
Document ID | / |
Family ID | 55067152 |
Filed Date | 2016-01-14 |
United States Patent
Application |
20160010261 |
Kind Code |
A1 |
KIM; Youngjun ; et
al. |
January 14, 2016 |
WASHING MACHINE
Abstract
A washing machine including a suspension to support an outer tub
so as to absorb vibrations of the outer tub. The suspension
includes an outer tub supporter disposed so as to be movable along
a support rod, an elastic member to elastically support the outer
tub supporter, a first friction unit to apply frictional force
between the first friction unit and the support rod, and a second
friction unit disposed above the first friction unit and movable
along the support rod, the second friction unit applying frictional
force between the second friction unit and the support rod, the
second friction unit being displaceable relative to the outer tub
supporter within a space delimited by the outer tub supporter.
Inventors: |
KIM; Youngjun; (Seoul,
KR) ; Yu; Insik; (Seoul, KR) ; KIM;
Youngjong; (Seoul, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
LG ELECTRONICS INC. |
Seoul |
|
KR |
|
|
Family ID: |
55067152 |
Appl. No.: |
14/796631 |
Filed: |
July 10, 2015 |
Current U.S.
Class: |
68/23.2 |
Current CPC
Class: |
D06F 37/24 20130101;
D06F 37/268 20130101 |
International
Class: |
D06F 37/26 20060101
D06F037/26 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 11, 2014 |
KR |
10-2014-0087717 |
Claims
1. A washing machine comprising: a casing; an outer tub disposed
inside the casing, to receive wash water therein; a support rod
having one end connected to the casing, the other end of the
support rod having a support prop; an outer tub supporter to
support the outer tub, the outer tub supporter being disposed so as
to be movable along the support rod; an elastic member supported by
the support prop, the elastic member elastically supporting the
outer tub supporter; a first friction unit to apply frictional
force between the first friction unit and the support rod; and a
second friction unit disposed above the first friction unit and
movable along the support rod, the second friction unit applying
frictional force between the second friction unit and the support
rod, wherein the second friction unit is displaceable relative to
the outer tub supporter within a space delimited by the outer tub
supporter.
2. The washing machine of claim 1, wherein the outer tub supporter
includes: a seating portion forming a seating surface to allow the
outer tub to be seated thereon; and a receiving body including a
second receiving region extending downward from the seating portion
so as to receive the second friction unit therein and a first
receiving region formed below the second receiving region so as to
receive the first friction unit therein.
3. The washing machine of claim 2, wherein the receiving body
includes an opening configured to be open in a lateral direction so
as to outwardly expose the interior of at least one of the first
receiving region and the second receiving region.
4. The washing machine of claim 2, wherein the elastic member
elastically supports the seating portion.
5. The washing machine of claim 2, wherein the receiving body
includes a partition to separate the first receiving region and the
second receiving region.
6. The washing machine of claim 5, wherein the second friction unit
is moved downward by the seating portion and moved upward by the
partition.
7. The washing machine of claim 6, wherein at least one of the
seating portion and the partition includes a protrusion formed at a
portion thereof coming into contact with the second friction
unit.
8. The washing machine of claim 2, wherein the outer tub supporter
further includes an outwardly protruding portion extending downward
from the seating portion and protruding outward beyond the
receiving body.
9. The washing machine of claim 8, wherein the outwardly protruding
portion is supported by the elastic member.
10. The washing machine of claim 8, further comprising: a cover
coupled to the outer tub supporter, a lower end portion of the
cover protruding outward from the outer tub supporter being
supported by the elastic member.
11. The washing machine of claim 10, wherein any one of the cover
and the second friction unit is formed with a vertically extending
guiding groove and the other one is formed with a guiding
protrusion to be guided along the guiding groove.
12. The washing machine of claim 11, wherein the second friction
unit includes: a tubular friction member housing to be fitted
around the support rod; and a friction member disposed inside the
tubular friction member housing so as to generate friction with the
support rod, and wherein the guiding groove or the guide protrusion
is formed at the tubular friction member housing.
13. The washing machine of claim 1, wherein the second friction
unit includes a friction member formed of a flexible material to
apply friction between the second friction unit and an outer
circumferential surface of the support rod.
14. The washing machine of claim 13, wherein the friction member
includes a collision portion on one or both of an upper end of the
friction member or a lower end of the friction member which
collides with the second receiving region when the friction member
is moved along the support rod, and the collision portion has a
convex shape more raised than a peripheral portion.
15. The washing machine of claim 14, wherein the friction member
includes convex portions corresponding to the convex shape and
concave portions near the convex portions, the convex portions and
the concave portions being alternately formed.
16. The washing machine of claim 15, wherein the friction member
takes the form of a sheet wound around the support rod.
17. The washing machine of claim 1, wherein the first friction unit
is disposed so as to be fixed to the outer tub supporter.
18. A washing machine comprising: a casing; an outer tub disposed
inside the casing, receive wash water therein; a support rod having
one end connected to the casing, the other end of the support rod
having a support prop; an outer tub supporter to support the outer
tub, the outer tub supporter being disposed so as to be movable
along the support rod; an elastic member supported by the support
prop, the elastic member elastically supporting the outer tub
supporter; and a first friction unit and a second friction unit
movable along the support rod so as to apply frictional force
between the first and second friction units and the support rod,
wherein the second friction unit is located above the first
friction unit, and wherein only the first friction unit is
integrally moved with the outer tub supporter while the outer tub
vibrates within a prescribed amplitude of vibration, and the first
friction unit and the second friction unit are moved together while
the outer tub vibrates at a greater amplitude of vibration than the
prescribed amplitude of vibration.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the priority benefit of Korean
Patent Application No. 10-2014-0087717, filed on Jul. 11, 2014 in
the Korean Intellectual Property Office, the disclosure of which is
incorporated herein by reference.
BACKGROUND
[0002] 1. Field
[0003] The present disclosure relates to a washing machine, and
more particularly, to a washing machine which is capable of
effectively attenuating vibrations.
[0004] 2. Description of the Related Art
[0005] Generally, a washing machine is an apparatus that washes
laundry using, for example, emulsified detergent, water streams
generated by the rotation of a wash tub or a pulsator, and shock
applied by the pulsator. The washing machine implements washing,
rinsing, and/or dehydration to remove contaminants attached to
laundry (hereinafter referred to as "clothing") using the action of
detergent and water.
[0006] A conventional washing machine includes a casing forming the
external appearance of the washing machine, an outer tub suspended
inside the casing, and an inner tub rotatably provided inside the
outer tub. In addition, the washing machine further includes a
suspension to prevent the outer tub from vibrating due to the
rotation of the inner tub and/or the pulsator.
[0007] The suspension is typically configured to attenuate
vibrations generated from the outer tub using, for example, the
elasticity/restoration of springs or the viscosity of fluid.
However, although this suspension may effectively attenuate
vibrations in the normal vibration state, in which the outer tub
vibrates within a given amplitude range, it is limited in the
attenuation of vibrations in the excessive vibration state, in
which the outer tub vibrates at a greater amplitude than that of
the normal vibration state. when the suspension is designed to be
optimized for the excessive vibration state exhibiting a greater
amplitude, the ability to attenuate normal vibrations, having a
relatively small amplitude, is deteriorated. In contrast, when the
suspension is designed to be optimized for the normal vibration
state, vibration attenuation sufficient to attenuate excessive
vibrations cannot be expected. Therefore, there is a need to find a
method for effectively attenuating vibrations both in the normal
vibration state and the excessive vibration state.
[0008] Additionally, the suspension may be provided with a friction
member which provides frictional force while moving along a support
rod during the vibration of the outer tub. In this case, the
friction member undergoes material degeneration due to frictional
heat generated by the frictional force applied between the friction
member and the support rod, which results in considerable reduction
of friction and, in the worst case, causes the friction member to
stick to the support rod.
SUMMARY
[0009] Therefore, embodiments of the present invention are made to
solve the problems as described above and it is an object to
provide a washing machine in which a friction member generates
friction to attenuate vibrations while moving along a support rod
in such a manner as to prevent overheating of the friction
member.
[0010] It is another object to provide a washing machine which is
capable of effectively reducing vibrations not only in the normal
vibration state, in which the amplitude of an outer tub is within a
prescribed range, but also in the excessive vibration state, in
which the amplitude of the outer tub deviates from the prescribed
range.
[0011] It is an object to provide a washing machine which is
capable of attenuating vibrations of an outer tub, thereby
achieving the improved utility of space inside a casing and,
especially, the increased capacity of the outer tub compared with
the related art.
[0012] It is yet another object to provide a washing machine which
is capable of achieving enhanced durability and stability and
reducing the generation of noise due to vibrations.
[0013] In accordance with one embodiment of the present invention,
the above and other objects can be accomplished by the provision of
a washing machine including a casing, an outer tub disposed inside
the casing to receive wash water therein, a support rod having one
end connected to the casing, the other end of the support rod
having a support prop, an outer tub supporter to support the outer
tub, the outer tub supporter being disposed so as to be movable
along the support rod, an elastic member supported by the support
prop, the elastic member elastically supporting the outer tub
supporter, a first friction unit to apply frictional force between
the first friction unit and the support rod, and a second friction
unit disposed above the first friction unit so as to be movable
along the support rod, the second friction unit applying frictional
force between the second friction unit and the support rod, the
second friction unit being displaceable relative to the outer tub
supporter within a space delimited by the outer tub supporter.
[0014] In accordance with another embodiment of the present
invention, there is provided a washing machine including a casing,
an outer tub disposed inside the casing to receive wash water
therein, a support rod having one end connected to the casing, the
other end of the support rod having a support prop, an outer tub
supporter to support the outer tub, the outer tub supporter being
disposed so as to be movable along the support rod, an elastic
member supported by the support prop, the elastic member
elastically supporting the outer tub supporter, and a first
friction unit and a second friction unit movable along the support
rod so as to apply frictional force between the first and second
friction units and the support rod, wherein the second friction
unit is located above the first friction unit, and wherein only the
first friction unit is integrally moved with the outer tub
supporter while the outer tub vibrates within a prescribed
amplitude of vibration, and the first friction unit and the second
friction unit are moved together while the outer tub vibrates at a
greater amplitude of vibration than the prescribed amplitude of
vibration.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The embodiments will be described in detail with reference
to the following drawings in which like reference numerals refer to
like elements wherein:
[0016] FIG. 1 is a side sectional view of a washing machine
according to one embodiment of the present invention;
[0017] FIG. 2 is a partial perspective view illustrating a
configuration in which a suspension is mounted to an outer tub
illustrated in FIG. 1;
[0018] FIG. 3 is a partial enlarged view of portion A illustrated
in FIG. 2;
[0019] FIG. 4 is a view illustrating a suspension according to one
embodiment of the present invention;
[0020] FIG. 5 is a view illustrating the operation sequence of the
suspension according to one embodiment of the present invention
when the vibration displacement of the outer tub increases
downward;
[0021] FIG. 6 is a view illustrating the operation sequence of the
suspension according to another embodiment when the downward
displacement of the outer tub gradually increases;
[0022] FIG. 7 is a view illustrating the longitudinal cross
sections of a first friction unit and a second friction unit
located inside an outer tub supporter;
[0023] FIG. 8 is a sectional view illustrating a suspension
according to another embodiment of the present invention;
[0024] FIG. 9 is a view illustrating one embodiment of a second
friction member;
[0025] FIG. 10 is a front view illustrating a suspension according
to a further embodiment of the present invention;
[0026] FIG. 11 is a view illustrating the state after the removal
of a cover compared with FIG. 10;
[0027] FIG. 12(a) is a view illustrating a friction member
according to a further embodiment of the present invention, and
FIG. 12(b) is a view illustrating a second friction unit including
the same; and
[0028] FIG. 13 is a view illustrating a second friction member
housing formed with a guiding protrusion and a cover formed with a
guiding groove to guide movement of the guiding protrusion.
DETAILED DESCRIPTION
[0029] Advantages, features, and methods for achieving those of
embodiments may become apparent upon referring to embodiments
described later in detail together with attached drawings. However,
embodiments are not limited to the embodiments disclosed
hereinafter, but may be embodied in different modes. The same
reference numerals may refer to the same elements throughout the
specification.
[0030] FIG. 1 is a side sectional view of a washing machine
according to one embodiment of the present invention. FIG. 2 is a
partial perspective view illustrating a configuration in which a
suspension is mounted to an outer tub illustrated in FIG. 1. FIG. 3
is a partial enlarged view of portion A illustrated in FIG. 2. FIG.
4 is a view illustrating a suspension according to one embodiment
of the present invention. FIG. 5 is a view illustrating the
operation sequence of the suspension according to one embodiment of
the present invention when the vibration displacement of the outer
tub increases downward. FIG. 6 is a view illustrating the operation
sequence of the suspension according to another embodiment when the
downward displacement of the outer tub gradually increases.
[0031] Referring to FIGS. 1 to 4, the washing machine according to
one embodiment of the present invention includes a casing 1 which
defines the external appearance of the washing machine, a control
panel 11 which includes, for example, operating keys to receive
various control instructions input by a user and a display unit to
display information regarding the operating state of the washing
machine, thereby constituting a user interface, and a door 7 which
is rotatably coupled to casing 1 to open or close an
introduction/removal hole (not illustrated) for the introduction
and removal of laundry.
[0032] An outer tub 2, in which wash water is received, is
suspended inside casing 1 by a support rod 15, and an inner tub 3,
in which laundry is received, is provided inside outer tub 2 so as
to be rotatable about a vertical axis. A pulsator 4 is rotatably
installed at the bottom of inner tub 3. Inner tub 3 has a plurality
of holes for the passage of wash water.
[0033] Although the casing defined in the present disclosure is
sufficient so long as it forms the external appearance of the
washing machine, in particular, the casing may be a stationary body
which is immovable so that one end of support rod 15, which
suspends outer tub 2 inside the casing, may be fixed by the casing.
Casing 1 as described below is merely one example of a structure
forming the external appearance of the washing machine and it is
specified that the range of the casing described in the claims of
the present application should not be limited thereto.
[0034] Casing 1 includes a cabinet 12 having an open upper side and
a top cover 14 provided at the upper side of cabinet 12, top cover
14 being formed at an approximately central portion thereof with an
introduction/removal hole for the introduction and removal of
laundry.
[0035] Support rod 15 extends by a long length in the longitudinal
direction thereof and has one end connected to casing 1 and the
other end connected to outer tub 2 via a suspension 100. One end of
support rod 15 may be connected to any one of cabinet 12 and top
cover 14, and cabinet 12 or top cover 14 may include a connector
(not illustrated) which is pivotally connected to support rod
15.
[0036] Support rod 15 may include a support prop 140 provided at
the other end thereof. Support prop 140 serves to support an
elastic member 150 fitted around support rod 15 so as not to be
separated from support rod 15. Support prop 140 has a support
surface to support a lower end of elastic member 150 so as to
prevent elastic member 150 from being separated from support rod
15, and the support surface may have a greater area than the cross
section of support rod 15.
[0037] Rotation of elastic member 150 about support rod 15 may be
restricted by support prop 140. In some embodiments, support prop
140 may be formed with a coupling portion to be coupled to the
lower end of elastic member 150, or may be formed with a raised
portion to limit the rotation of the lower end of elastic member
150.
[0038] A water supply flow path 5 is connected to an external water
source such as, for example, a water tap to supply water into outer
tub 2 and/or inner tub 3. A water supply valve 6 is provided to
control water supply flow path 5. A drive unit 13 serves to drive
inner tub 3 and/or pulsator 4. A drain flow path 9 is connected to
outer tub 2 to discharge wash water from outer tub 2. A drain valve
8 is provided to control drain flow path 9. A drain pump 10 is
installed to drain flow path 9 to pump the discharged wash water to
the outside of the washing machine.
[0039] Suspension 100 serves to attenuate vibrations of outer tub 2
attributable to the rotation of inner tub 3 or pulsator 4.
Suspension 100 includes an outer tub supporter 110, elastic member
150, a first friction unit 120, and a second friction unit 130.
[0040] Suspension 100 is coupled to a lower portion of outer tub 2.
This coupling may be separable coupling to ensure easy installation
and separation of suspension 100. For example, FIG. 3 illustrates a
mount 2a which protrudes from the outer circumferential surface of
a lower portion of outer tub 2 for the installation of suspension
100, and mount 2a is formed with a slit 2b which extends in the
vertical direction and is open in the lateral direction.
[0041] To couple suspension 100 and outer tub 2 to each other, once
suspension 100 has been installed to support rod 15, support rod 15
is inserted into mount 2a through a lateral opening of slit 2b and
mount 2a is seated on outer tub supporter 110 that will be
described below. Since the weight of outer tub 2 is continuously
applied to outer tub supporter 110, outer tub 2 and outer tub
supporter 110 are integrally moved without separation. Meanwhile,
separation of suspension 100 for maintenance and repair is easily
implemented by pulling suspension 100 slightly downward and
removing support rod 15 through the lateral opening of slit 2b.
[0042] Outer tub supporter 110 is configured to support outer tub 2
and is movable along support rod 15. Outer tub supporter 110 may
include a tubular slider 111 for the penetration of support rod 15
and a seating portion 112 expanding outward from slider 111 to form
a seating surface 112a on which outer tub 2 is seated. Seating
portion 112 may be caught by mount 2a of outer tub 2 and at least a
portion of slider 111 may protrude upward from mount 2a. A
lubricant such as, for example, grease may be applied to a portion
of slider 111 coming into contact with support rod 15 (i.e., the
inner circumferential surface of an inner elongated bore).
[0043] First friction unit 120 and second friction unit 130 are
movable along support rod 15 respectively such that frictional
force (more particularly, kinetic friction during the vibration of
outer tub 2) is generated between the respective friction units and
support rod 15. Second friction unit 130 is located above first
friction unit 120. Outer tub supporter 110 may include a first
receiving region S1 to receive first friction unit 120 and a second
receiving region S2 formed above first receiving region S1 to
receive second friction unit 130.
[0044] First friction unit 120 may be fixed to outer tub supporter
110. In this case, the vertical length of first receiving region S1
is substantially equal to the vertical length of first friction
unit 120.
[0045] First receiving region S1 and second receiving region S2 may
be formed in a receiving body 113 which extends downward from
seating portion 112. Receiving body 113 is located inside elastic
member 150. Receiving body 113 may include a bottom portion 113d
spaced apart from seating portion 112 and one or more side portions
113a and 113b connecting seating portion 112 and bottom portion
113d to each other. Receiving body 113 may have one or more lateral
openings 116 and 117 which are open in the lateral direction to
allow first friction unit 120 or second friction unit 130 to be
easily inserted into receiving region S1 or S2. In the present
embodiment, a pair of first lateral openings 116, which communicate
with the interior of first receiving region S1, and a pair of
second lateral openings 117, which communicate with the interior of
second receiving region S2, are formed between first side portion
113a and second side portion 113b. First lateral openings 116 and
second lateral openings 117 are separated from each other by a
partition 113c. Lateral openings 116 and 117 function not only to
provide easy installation and separation of friction units 120 and
130, but also to dissipate heat generated from friction units 120
and 130. Additionally, a lubricant may be directly injected to
friction units 120 and 130 through lateral openings 116 and 117,
which provides convenience in maintenance and repair.
[0046] Partition 113c vertically divides a space inside receiving
body 113 between the lower surface of seating portion 112 and
bottom portion 113d. On the basis of partition 113c, first
receiving region S1 is a lower region of receiving body 113 and
second receiving region S2 is an upper region of receiving body
113. Partition 113c may connect first side portion 113a and second
side portion 113b to each other.
[0047] With regard to first receiving region S1, the distance
between bottom portion 113d and partition 113c is substantially
equal to the vertical length of first friction unit 120. Thus,
first friction unit 120 is fixed to first receiving region S1 and
moves integrally with outer tub supporter 110 during the vibration
of outer tub 2.
[0048] Second receiving region S2 is formed to allow outer tub
supporter 110 to be displaceable relative to second friction unit
130. That is, with regard to second receiving region S2, the
distance from seating portion 112 to partition 113c is greater than
the vertical length of second friction unit 130, such that outer
tub supporter 110 is movable in a section corresponding to the
length difference while being separated from second friction unit
130.
[0049] Second receiving region S2 may be formed with protrusions
118a and 118b at a region thereof which will come into contact with
second friction unit 130 when outer tub supporter 110 is moved
along with second friction unit 130. More specifically, seating
portion 112 may include upper protrusions 118a which protrude
downward from the lower surface of seating portion 112 to the
interior of second receiving region S2. Upper protrusions 118a may
be formed around an aperture for the passage of support rod 15.
Likewise, partition 113c may include lower protrusions 118b which
protrude upward to the interior of second receiving region S2.
Lower protrusions 118b may be formed around an aperture for the
passage of support rod 15. During the vibration of outer tub 2,
second friction unit 130 is moved downward by being pushed by upper
protrusions 118a and moved upward by being pushed by lower
protrusions 118b. This configuration in which second receiving
region S2 is provided with protrusions 118a and 118b may reduce the
collision area between outer tub supporter 110 and second friction
unit 130, thereby reducing collision noise.
[0050] Meanwhile, friction between two friction units 120 and 130
and support rod 15 exhibits different aspects based on the
amplitude of vibration of outer tub 2. For example, when operating
the washing machine, in the case where outer tub 2 resonates based
on the physical properties of the entire vibration system, or for
an excessive vibration period, during which excessive vibrations
are generated due to the unbalanced arrangement of clothing inside
inner tub 3, first friction unit 120 and second friction unit 130
are moved integrally with outer tub supporter 110, causing kinetic
friction between friction units 120 and 130 and support rod 15.
Accordingly, for the excessive vibration period, vibration energy
is more positively dissipated by friction of both first and second
friction units 120 and 130.
[0051] On the other hand, for a period, during which the amplitude
of vibration of outer tub 2 is sufficiently lower than that of the
excessive vibration period (e.g., a normal vibration period),
second friction unit 130 remains at a given position on support rod
15 while being separated from outer tub supporter 110, and outer
tub supporter 110 is displaced relative to second friction unit
130. Accordingly, second friction unit 130 does not function to
attenuate vibrations, whereas first friction unit 120 is
continuously moved integrally with outer tub supporter 110 so as to
dissipate vibration energy. Outer tub 2 can vibrate relatively
freely because vibration attenuation by friction is implemented
only by first friction unit 120.
[0052] Suspension 100 implements vibration attenuation using one
friction unit 120 during the relatively stable period (e.g., a
normal vibration period), but implements positive attenuation by
friction using two friction units 120 and 130 during the excessive
vibration period while the washing machine is operating. That is,
the washing machine according to the present embodiment allows
outer tub 2 to be moved relatively freely within a predetermined
allowable amplitude range in consideration of, for example, the
durability of the appliance and an allowable vibration
displacement, but more positively attenuates vibrations to limit
the amplitude of vibration when vibrations are generated beyond a
given level. As such, the washing machine shows different aspects
of vibration attenuation based on the amplitude of vibration.
[0053] Meanwhile, although two friction units are provided as
described above, as a comparative embodiment to the present
embodiment, a suspension in which second friction unit 130 is
located below first friction unit 120 will be described below. The
following description is referenced with FIG. 6.
[0054] FIG. 6 illustrates the sequence of downward movement of an
outer tub supporter 110' in the case of excessive vibration. More
specifically, in FIG. 6(a) illustrating the case where outer tub 2
has been raised to an uppermost position during vibration, outer
tub 2 begins to be displaced downward. As exemplarily illustrated
in FIG. 6(a), first friction unit 120 begins to be moved integrally
with outer tub supporter 110', whereas a lower end of second
friction unit 130 is separated from outer tub supporter 110'.
Second friction unit 130 remains at a fixed position on support rod
15 until outer tub supporter 110' is moved downward and begins to
push an upper end of second friction unit 130 (see FIG. 6(b)). That
is, outer tub supporter 110' has been displaced independently of
second friction unit 130 starting from the state of FIG. 6(a) to
reach the state of FIG. 6(b).
[0055] In the state of FIG. 6(b), outer tub supporter 110' comes
into contact with second friction unit 130, and first friction unit
120 and second friction unit 130 begin to be moved together.
Thereafter, in FIG. 6(c) illustrating the case where outer tub 2
has been located at a lowermost position, second friction unit 130
remains in contact with outer tub supporter 110'. Although not
illustrated, after state of FIG. 6(c), outer tub supporter 110' is
again moved upward by the restoration force of elastic member 150,
thereby returning to the state of FIG. 6(a).
[0056] In FIGS. 6(a) to 6(c), during the downward movement of outer
tub 2, the area where friction by second friction unit 130 is
applied is designated by mf' and the area where friction by first
friction unit 120 is applied is designated by ff'. As is
exemplarily illustrated in FIGS. 6(a) to 6(c), an area cf' is
formed where the area mf' and the area ff' overlap each other. In
particular, the area cf' is a section where first friction unit 120
applies friction immediately after second friction unit 130 applies
friction. Thus, frictional heat is concentrated in the area cf'.
Accordingly, a portion of first friction unit 120 coming into
contact with support rod 15 may be degenerated by heat and,
depending on the material, may stick to support road 15. In
particular, since the downward movement of outer tub 2 accelerates
more than the upward movement of outer tub 2 due to gravity,
friction between friction units 120 and 130 and support rod 15 and
heat emission increase during the downward movement of outer tub 2.
Additionally, in the area cf', as outer tub 2 begins to be moved
upward from the lowermost position (FIG. 6(c)) again, friction by
first friction unit 120 is again applied for a given time, which
aggravates heat emission due to friction.
[0057] To solve the above-described problem, embodiments of the
present invention proposes to dispose second friction unit 130
below first friction unit 120. How this structure effectively
solves overheating due to friction compared with a comparative
embodiment will be described in detail with reference to FIG. 5.
First, reference characters designated in FIG. 5 are as follows.
[0058] (a): the case where outer tub 2 is located at the uppermost
position during vibration [0059] (b): the state in which outer tub
supporter 110 is moved downward and begins to push the upper end of
second friction unit 130 [0060] (c): the case where outer tub 2 is
located at the lowermost position [0061] .DELTA.H1: an area where
outer tub supporter 110 is displaced independently of second
friction unit 130 during the downward movement of outer tub 2
[0062] .DELTA.H2: a displacement of second friction unit 130 [0063]
mf: an area where friction is applied by second friction unit 130
[0064] ff: an area where friction is applied by first friction unit
120 [0065] cf: an area where the area mf and the area ff overlap
each other
[0066] As opposed to the previously described embodiment, friction
is not applied by second friction unit 130 immediately after
friction is applied by first friction unit 120 in the overlapping
area cf. After outer tub supporter 110 is moved independently of
second friction unit 130 at least in the area .DELTA.H1, friction
is applied by second friction unit 130. Accordingly, no increase in
frictional heat occurs in the area cf while outer tub supporter 110
is displaced by at least .DELTA.H1.
[0067] In some embodiments, assuming that the vertical length of
second receiving region S2 is increased to increase the independent
movement length of outer tub supporter 110 relative to second
friction unit 130, the time taken until second friction unit 130
enters the overlapping area cf after first friction unit 120 passes
through the overlapping area cf may be increased. In this sense, by
appropriately designing the maximum displaceable length of outer
tub supporter 110 relative to second friction unit 130, the
overlapping area cf may not be generated even in the case where the
amplitude of vibration is the same as the comparative
embodiment.
[0068] Meanwhile, when outer tub 2 is again moved upward from the
lowermost position, no friction is applied by second friction unit
130 for a given time until first friction unit 120 again reaches
the overlapping area cf and, correspondingly, the temperature
increase in the overlapping area cf may be restricted.
[0069] Meanwhile, although first friction unit 120 may be moved
integrally with outer tub supporter 110, in some embodiments, outer
tub supporter 110 may also be moved with a slight displacement
relative to first friction unit 120. However, even in this case,
the maximum displacement at which first friction unit 120 is
movable independently of outer tub supporter 110 is smaller than
the allowable maximum displacement for second friction unit
130.
[0070] Each of first friction unit 120 and second friction unit 130
may include at least one friction member to come into contact with
the outer circumferential surface of support rod 15. Hereinafter,
the friction member of each friction unit is referred to as a first
friction member 121 or a second friction member 131. These friction
members 121 and 131 may be formed of a porous fiber material such
as, for example, felt, or may be formed of an elastic material such
as, for example, rubber. In addition, in terms of the shape,
friction members 121 and 131 may have a tubular shape so as to be
fitted around support rod 15, or may take the form of a flexible
sheet or band so as to be wound around the outer circumferential
surface of support rod 15. In particular, the fibrous friction
member has excellent absorbency for a lubricant.
[0071] Elastic member 150 is supported by support prop 140 and
elastically supports outer tub supporter 110. In the present
embodiment, elastic member 150 is a compression spring which
elastically supports seating portion 112. As such, elastic member
150 is compressed when outer tub 2 is displaced downward and
elastically rebounds after being compressed beyond a given level so
as to push outer tub supporter 110 upward.
[0072] FIG. 7 is a view illustrating the longitudinal cross
sections of first friction unit 120 and second friction unit 130
located inside outer tub supporter 110. Referring to FIG. 7, first
friction unit 120 may include a tubular first friction member
housing 122 and first friction member 121 placed inside first
friction member housing 122 to generate friction between first
friction unit 120 and support rod 15.
[0073] Similar to first friction unit 120, second friction unit 130
may include a second friction member housing 132 and second
friction member 131 placed inside second friction member housing
132. Additionally, second friction unit 130 may further include a
shock absorbing member 133 located above and/or below second
friction member housing 132.
[0074] Shock absorbing member 133 may be formed of a porous fiber
material such as, for example, felt and serve to alleviate shocks
between second friction unit 130 and second receiving region S2 and
to reduce collision noise therebetween.
[0075] FIG. 8 is a sectional view illustrating a suspension
according to another embodiment of the present invention.
Suspension 200 according to the present embodiment is identical to
that of the previously described embodiment in that an outer tub
supporter 210 includes slider 111, seating portion 112, and
receiving body 113, but has a difference in that it further
includes outwardly protruding portions 219a and 219b which more
protrude outward from the periphery of receiving body 113 than side
portions 113a and 113b.
[0076] In this embodiment, outer tub supporter 210 includes the
first outwardly protruding portion 219a and the second outwardly
protruding portion 219b which extend downward from seating portion
112 with lateral openings 217 interposed therebetween, but is not
limited thereto. A single outwardly protruding portion may be
formed around the periphery of receiving body 113. In this case,
the outwardly protruding portion may be formed with an opening in a
region S thereof overlapping lateral opening 217 of receiving body
113.
[0077] Outwardly protruding portions 219a and 219b extend downward
from seating portion 112 and are supported at lower ends thereof by
elastic member 150. First receiving region S1 and second receiving
region S2 are formed in receiving body 113. In particular, at least
a part S of second receiving region S2 extends to the interior of
the outwardly protruding portions 219a and 219b. Outwardly
protruding portions 219a and 219b serve to enhance the rigidity of
outer tub supporter 210 and, in particular, reinforce the interface
between seating portion 112 and receiving body 113.
[0078] FIG. 9 is a view illustrating one embodiment of a second
friction member. Hereinafter, a friction member 231, which will be
described below with reference to FIG. 9, has substantially the
same configuration as suspension 100 according to the
above-described embodiment of the present invention, but is assumed
to be applied to a suspension (not illustrated) that is not
provided with protrusions 118a and 118b.
[0079] Referring to FIG. 9, second friction member 231 may take the
form of a sheet and may be wound around the outer circumference of
support rod 15 inside second friction member housing 132. Second
friction member 231 may be formed of a flexible fiber material or
rubber.
[0080] A portion of second friction member 231 which will collide
with second receiving region S2 when second friction member 131 is
moved along support rod 15 may be more raised than a peripheral
portion. The raised portion of second friction member 231 protrudes
outward from second friction member housing 132. As second friction
member 231 is moved along support rod 15, the raised portion comes
into contact with second receiving region S2. When second friction
member 231 collides with second receiving region S2, the raised
portion serves to alleviate shocks and to reduce the contact area
therebetween, resulting in reduced shock noise.
[0081] More specifically, as illustrated in FIG. 9, convex portions
231a and concave portions 231b may be alternately formed at an
upper end and a lower end of second friction member 231. In this
case, convex portions 231a formed at the upper end of second
friction member 231 come into contact with the lower surface of
seating portion 112, and convex portions 231a formed at the lower
end of second friction member 231 come into contact with the upper
surface of bottom portion 113d of receiving body 113. As such, even
in the case where no protrusions 118a and 118b are formed at second
receiving region S2, the contact area between second friction
member 231 and outer tub supporter 110 may be reduced and, in
particular, shock noise may be reduced thanks to shock absorption
by convex portions 231a.
[0082] FIG. 10 is a front view illustrating a suspension 300
according to a further embodiment of the present invention. FIG. 11
is a view illustrating the state after the removal of a cover 350
compared to FIG. 10. FIG. 12(a) is a view illustrating a friction
member 331 according to a further embodiment of the present
invention, and FIG. 12(b) is a view illustrating a second friction
unit 330 including the same. FIG. 13 illustrates a second friction
member housing 332 formed with a guiding protrusion 332c and cover
350 formed with a guiding groove 351 to guide movement of guiding
protrusion 332c. In particular, FIG. 13 is a cutaway view of cover
350 to show guiding groove 351.
[0083] Referring to FIGS. 10 to 13, suspension 300 according to the
present embodiment includes an outer tub supporter 210', and cover
350 coupled to outer tub supporter 210' and supported by elastic
member 150. Outer tub supporter 210' is similar to outer tub
supporter 210 of the previously described embodiment, but has a
difference in that it has no protrusions 218a and 218b. Thus, a
detailed configuration of outer tub supporter 210' follows the
above description, and a detailed description thereof will be
omitted below.
[0084] Cover 350 is configured as a component separate from outer
tub supporter 210' and is coupled to outwardly protruding portions
219a and 219b. Cover 350 may include a cover lower end portion 353
supported by elastic member 150 and an insertion portion 352
protruding upward from cover lower end portion 353 so as to be
inserted between the first outwardly protruding portion 219a and
the second outwardly protruding portion 219b. As insertion portion
352 is inserted into an opening between the first outwardly
protruding portion 219a and the second outwardly protruding portion
219b, cover 350 is constrained so as not to rotate about support
rod 15.
[0085] Cover 350 may be separably coupled to outer tub supporter
210'. This coupling is not necessarily limited to fixed coupling,
which maintains cover 350 and outer tub supporter 210' in an
integrated state after external force is removed. That is, even in
the case where cover 350 is freely separable from outer tub
supporter 210', cover 350 may be moved integrally with outer tub
supporter 210' due to the elastic support force of elastic member
150. Even in this case, both cover 350 and outer tub supporter 210'
are defined as maintaining the coupled state thereof.
[0086] Lower end portion 353 of cover 350 supported by elastic
member 150 has a ring shape and extends to the bottom of the
opening formed between the outwardly protruding portions 219a and
219b. Thus, the entire lower end portion 353 may be evenly
supported by elastic member 150.
[0087] One of the inner circumferential surfaces of cover 350 and
second friction unit 330 may be formed with a vertically extending
guide groove 351 and the other one may be formed with a guiding
protrusion 332c to be guided along guiding groove 351. In the
embodiment, vertical guiding protrusion 332c is formed at the outer
circumference of the second friction member housing 332 and guiding
groove 351 is formed in the inner circumferential surface of cover
350 such that guiding protrusion 332c is inserted into and guided
by guiding groove 351. Guiding protrusion 332c and guiding groove
351 may specify an accurate assembly position of second friction
unit 330 and allow second friction unit 330 to be stably moved
along support rod 15 without shaking.
[0088] Second friction unit 330 may include a second friction
member 331 formed with convex portions 331a at an upper end and/or
a lower end thereof, and a second friction member housing 332 in
which two or more second friction members 331 are received at upper
and lower positions.
[0089] Second friction member 331 may take the form of a sheet and
may be alternately formed with convex portions 331a and concave
portions 331b. Second friction member 331 may be wound around the
outer circumference of support rod inside second friction member
housing 332. Second friction member 331 may be formed of a flexible
fiber material or rubber.
[0090] Second friction member housing 332 internally forms a space
in which two or more second friction members 331 may be received.
Second friction members 331 are received in an upper region 332a
and a lower region 332b of the space. At this time, convex portions
331a of each second friction member 331 may protrude upward or
downward from the second friction member housing 332 so as to come
into contact with the second receiving region S2 when second
friction unit 330 is moved along support rod 15. Second friction
member housing 332 may include a dividing member such as, for
example, a rib or a partition which divides the space into the
upper region and the lower region.
[0091] Although second friction member 331 is similar to second
friction member 231 as described above in that it has convex
portions 331a and concave portions 331b, in consideration of a
structure in which the two second friction members 331 are received
at upper and lower positions inside the second friction member
housing 332, it is sufficient to provide convex portions and
concave portions at only one of the upper and lower ends of each
second friction members 331 (see FIG. 12(a)).
[0092] As is apparent from the above description, the washing
machine of the present disclosure has the effect of preventing the
area where the movement ranges of a first friction unit and a
second friction unit, which are arranged at upper and lower
positions along a support rod, from being overheated by frictional
heat. Accordingly, embodiments of the present invention have the
effect of preventing the material of the portions of the first
friction unit and the second friction unit that come into contact
with the support rod from being degenerated by heat.
[0093] In addition, since the attenuation of friction by the first
friction unit and the second friction unit may be stably realized
and the portions of the first and second friction units that come
into contact with the support rod may be maintained rigid without
deformation, embodiments of the present invention have the effect
of enabling the first and second friction units to be moved along
the support rod without shaking.
[0094] In addition, embodiments of the present invention have the
effect of effectively attenuating vibrations not only in the normal
vibration state in which the amplitude of vibration of an outer tub
is within a prescribed range, but also in the excessive vibration
state in which the amplitude of vibration of the outer tub deviates
from the prescribed range.
[0095] In addition, embodiments of the present invention have the
effect of attenuating vibrations of the outer tub, thereby
achieving the improved utility of space inside a casing and,
especially, increasing the capacity of the outer tub.
[0096] In addition, embodiments of the present invention have the
effect of achieving enhanced durability and stability of the
washing machine and reducing the generation of noise due to
vibrations.
[0097] Although embodiments have been described with reference to a
number of illustrative embodiments thereof, it should be understood
that numerous other modifications and embodiments can be devised by
those skilled in the art that will fall within the spirit and scope
of the principles of this disclosure. More particularly, various
variations and modifications are possible in the component parts
and/or arrangements of the subject combination arrangement within
the scope of the disclosure, the drawings and the appended claims.
In addition to variations and modifications in the component parts
and/or arrangements, alternatives uses will also be apparent to
those skilled in the art.
* * * * *