EP2643512B1

EP2643512B1 - Home appliance with a vibration damping device

Info

Publication number: EP2643512B1
Application number: EP11787909.8A
Authority: EP
Inventors: Ismael Gracia Bobed; Gerardo Martinez Perez; Eduardo Recio Ferrer
Original assignee: BSH Hausgeraete GmbH
Current assignee: BSH Hausgeraete GmbH
Priority date: 2010-11-26
Filing date: 2011-11-25
Publication date: 2016-09-07
Anticipated expiration: 2031-11-25
Also published as: EP2643512A1; WO2012069648A1; CN103228834B; RU2553039C2; CN103228834A; RU2013126296A; PL2643512T3

Description

The invention relates to a home appliance, in particular a washing machine or a dryer, with a housing in which a laundry drum is rotatably mounted in a laundry tub, the laundry tub being coupled to the housing via at least one support element of a vibration damping device including pivot articulations comprising a first pivot articulation. The support element is articulated to the housing via a pivot lever which is articulated to the housing, particularly to a housing side, via the first pivot articulation about a first pivot axis fixed with respect to the housing.
A home appliance of this type is disclosed in each of the documents DE 1 211 555 B , EP 0 535 443 A1 and EP 0 531 917 A1 .
Conventionally, washing machines and dryers with a drum rotatably mounted in a tub comprise a vibration damping device, which couples the tub with the housing, thereby vibrations and noise caused by the rotation of the drum are damped. Usually, the tub vibrations are absorbed by means of a piston-cylinder damper device with an axial friction damper.
JP-1111-4280-A describes a washing machine with a damper, which is disposed onto the housing of the washing machine in a direction perpendicular with respect to the drum rotational axis.
WO-2007/013021-A1 describes a conventional home appliance with a piston-cylinder vibration damping device, which connects a laundry tub with the housing base of the home appliance. The cylinder-piston vibration damping device is slideably mounted on the housing base, in such a way that a limited sliding motion of the piston-cylinder device is provided along the housing base. Thus, at least part of the vibrations of the tub during operation can be transferred into a linear sliding motion of the piston-cylinder device. The disadvantage of such vibration damping device is that it is relatively expensive.
An object of the present invention is to provide a home appliance with an easy to assemble and manufacture vibration damping device.
Another object is to provide a more compact home appliance, i.e. a home appliance with a greater ratio of volume of the tub to volume of the housing than that of conventional home appliances with cylinder-piston vibration damping devices.
These and other objects of the present invention are solved by the features of the independent claims. Preferred embodiments of the invention are disclosed in the dependent claims.
The support element is articulated to the housing via a pivot lever. In this way, the tub vibrations during operation in a direction along the extension of the support element are transferred to the pivot lever. The oscillations or vibrations of the support element are converted into rotation motion at least partially by means of the pivot lever, so that the vibrations are damped at least partially. The pivoting lever is articulated to the housing via a first pivot articulation about a first pivot axis fixed to the housing, particularly to a housing side.
Hereinafter without otherwise stated, dimensions should be understood as determined at a position of the home appliance where the tub is unloaded and remains static relative to the housing during no operation of the home appliance. In this sense, relative terms such as vertical, horizontal, above, below, height, etc. should be understood as referred to the position in which the home appliance is to be disposed during operation.
According to the invention, at least one of the pivot articulations includes a rotational friction damper, and the first pivot axis is above a horizontal plane passing through the lowest point of the tub.
According to the invention, pivot lever and/or the support element is articulated against a predetermined rotational friction torque. For that, at least one of the pivot articulations includes a rotational friction damper. In this way, at least part of the translational energy caused by the vibrations can be converted into friction energy. By means of the conversion of translational energy into friction energy, it can be totally eliminated the need of an axial friction damper, though it is also contemplated that the support element and/or the pivot lever comprises an axial friction damper.
Advantageously, such a vibration damping device is easy to implement as far as technical issues of its components are concerned. In particular, the assembly process is simplified, since a number of components of the first pivot articulation may be mounted on the housing in a previous step. The coupling of the tub to the housing via the vibration damping device may be arranged easily as far as technical issues of the assembly process are concerned.
The reaction force that is transferred to the housing through the damping device of the invention can be significantly reduced as compared to that of conventional axial friction dampers, consequently bending and shearing stresses at the connection to the housing are reduced as well. This somewhat precludes the utilization of axial friction dampers coupled to the housing side. Furthermore, there is no need to provide long enough support elements in order to adequately dissipate friction energy from the friction dampers without failure in buckling or longitudinal bending as it is the case of axial friction dampers.
The first pivot axis may be at a height above a housing base of the home appliance. In this way a space is released under the tub where other components can be allocated, such as a drawer which can be useful to store inside any items by the user. This enables to reduce the overall height of the home appliance and hence to provide a more compact home appliance. In this way, It is also possible to provide multiple configurations of home appliances with for example at least one drawer up and/or down beside a compact home appliance module, a tank for storing water of the last rinsing cycle or a tank for storing detergent of a detergent dosing system.
The first pivot axis may be connected to the housing, particularly to the housing side, via a bracket element, so as to provide rigidity to the housing structure at the connection. The bracket element may be a cross plate fixed to the corners of the housing side. Optionally the bracket element is not contacting the housing in order to reduce vibrations being transferred to the housing. In this way the vibrations are better damped. Alternatively, the bracket element may be a bearing pin which extends along the direction of the first pivot axis where the pivot lever is connected. This allows providing a more flexible bracket element.
Preferably, the pivot lever may be articulated to the support element via a second pivot articulation about a second pivot axis movable with respect to the housing. In particular preferably, the support element may be articulated to the tub via a third articulation fixed to the tub. This arrangement provides a simple solution in terms of technical components to the problem of providing a motion to the support element and, thus, for damping tub vibrations during operation.
Hereinafter, the term "housing ceiling" may be defined as an upper plane of the home appliance where the tub springs are suspended from.
Preferably, the first, second and/or third pivot articulation may comprise a bearing bushing, in which at least a bearing pin is rotatably connected, especially with a press-fit connection. By this means, it can be devised a design which enables a reliable and safe operation, as well as avoid maintenance of one or of a number of the pivot articulations. More preferably, the bearing pin of the first pivot articulation may be rotatably connected to the bearing bushing with a rotational friction torque resistance. The bearing pin may be tubular shaped and be made of a thermal conductive material, especially of metal, so that the temperature can be dissipated quickly thereby allowing to extent the life of the friction layers.
In particular, the support element and/or the pivot lever are rigid components. The complexity of the vibration damping device can thus be further reduced. Furthermore, simple manufacturing components can be used. They may also be made of a rigid material having enough elasticity to withstand the friction at the articulations. Particularly, the support element and/or the pivot lever are made of plastic.
The support element length may be equal to or greater than the pivot lever length. Also, the tub may have projections that allow providing a more spaced first pivot articulation from the drum rotational axis in order to be able to make the support element length shorter. Thus, a rotational friction torque acting on the first articulation through the pivot lever can be reduced.
Preferably, the support element or a force line of action of the support element is located at an effective lever arm distance from the first pivot articulation. The effective lever arm distance is measured perpendicularly to the force line of action and may vary due to vibrations of the tub during operation.
Optionally, in the case in which the first pivot articulation is located at a height above the housing base of the home appliance, said height and/or a pivot lever length and/or a support element length, and/or the effective lever arm distance may be selected so as to provide an improved damping effect, particularly at a resonance vibration frequency. The pivot lever length and the support element length are measured between respective pivot axes. The improved damping effect includes minimizing vibration amplitudes, minimizing vibration reaction force at the connection to the housing, etc. as it would be recognized by a person skilled in the art. In this sense, it has been observed that a variable friction coefficient depending on the stroke of the damping device can be achieved with the features of the invention.
In a preferred embodiment, the support element length is greater than twice a pivot lever length.
Optionally, the home appliance according to the invention comprises a vibration control system. The vibration control system may comprise a goniometer sensor for obtaining the angle between the pivot lever and the support element during operation of the home appliance so as to allow determination of the position of the third pivot articulation and the tub with respect to the housing in a reliable and easy way. This enables for example to extra minimize vibration amplitudes and therefore allowing providing a more compact home appliance.
Optionally, it is also contemplated that the vibration damping device may comprise at least one antitorque element connected to the pivot lever for preventing twisting of the pivot lever about its longitudinal axis and/or the turning about an axis perpendicular to the first pivot axis during operation, by contact reaction of the antitorque element against a reaction element fixed with respect to the first pivot axis. Particularly, the antitorque element may be configured as a silentbloc joint. More particularly, the antitorque element may be integrated in the pivot lever. On the other hand, the reaction element may be constituted by the bearing pin. In a preferred embodiment, it may be provided at least one antitorque element on either side of the pivot lever. The incorporation of an antitorque element enables to reduce the number of vibration damping device down even to two.
Particularly preferably, the home appliance comprises at least two support elements with at least one support element disposed at either side of the tub with respect to a vertical central plane. This arrangement of the support elements allows a reliable vibration damping of the tub.
Finally, other secondary features that may be incorporated to the washing machine of the invention in order to provide a more compact home appliance are as follows. The home appliance drive motor may be of a BLDC type, the counterweights may be allocated on front and/or back sides of the tub, the control panel may be located at the appliance's door or at a side of the front panel upper part and the detergent dispenser may be placed also at the appliance's door or also compacted at the front panel upper part. The door also may close directly the tub without any gasket between the front wall saving space in appliance depth.
Below, two preferred embodiments of the invention are described with reference to the figures contained in the attached drawings. In the drawings:

Figure 1 is a perspective view of a washing machine with a washing machine door opened;
Figure 2 is a sectional view of the washing machine in the plane AA of Figure 1 with a vibration damping device according to the invention;
Figure 3 shows a sectional view of a support element and a pivot lever of the vibration damping device of Figure 2;
Figure 4 is a schematic representation of a support element and a pivot lever of the vibration damping device of Figure 2;
Figure 5 shows a perspective view of a support member and a pivoting lever of the vibration damping device of Figure 2;
Figure 6 shows a perspective view of a support member and a pivoting lever of the vibration damping device of Figure 2;

Figure 1 shows a washing machine 1 with a housing 3. At a housing front 5 of the housing 3 it is provided a washing machine door 7 for closing the load opening 9. According to Figure 1, the door 7 is represented in an opened position, so that through the load opening 9 of the housing front it is visible a laundry drum 11 for moving laundry items (not shown).
Figure 2 shows a drum 13 of the washing machine 1 along the sectional plane A-A. As it is apparent from Figure 2, the drum 11 is rotatably mounted in the tub about a drum rotational axis 15, driven by a drive motor 25. Power is transmitted via a transmission belt 27 which is functionally engaged to the back side of the tub 11 via a driven pulley 29.
The tub 13 is suspended via two springs 17 onto a housing ceiling 19 of the housing 3. At the bottom, the tub 13 is coupled to the housing sides 35 via two rod shaped support elements 31 articulated to the housing side 35 via pivot levers 33. In this case, the support elements 31 are arranged symmetrically one to each other with respect to a central vertical plane of the tub 13. More than one support element 31 may be disposed on at least one of the housing sides 35.
The springs 17, the support elements 31, and the pivot levers 33 constitute a vibration damping device of the washing machine 1. By means of the vibration damping device, vibrations of the tub 13 during operation of the drum 11 are absorbed and damped.
According to Figure 2, the pivot lever 33 is articulated to the housing side 35 via a first pivot articulation 37 about a first pivot axis 39 fixed with respect to the housing 3. At the opposite side of the first pivot articulation 37, the pivot lever 33 is articulated to the support element 31 via a second pivot articulation 47 about a second pivot axis 49 movable with respect to the housing 3. On the contrary, at the opposite side of the support element 31 to the second pivot articulation 47, the support element 31 is articulated to the tub 13 via a third pivot articulation 51 fixed to the tub 13. The support member length a may be less than, equal to or greater than the pivot lever length b.
Figure 3 shows a sectional view of one of the support elements 31 of Figure 2 with the pivot lever 33. The first pivot articulation 37 has a bearing pin 43 fixed to a plate bracket element 45 fixedly coupled to the housing side 35 close to the pivot lever 33, which is fixedly connected to a bearing bushing 41, which may be realized by plate cutting and bending of a plate bracket element 45. According to Figure 3, the articulation of the pivot lever 33 to the housing side 35 is arranged like a crankshaft.
Furthermore, Figure 3 shows that the bearing pin 43 is mounted with a press-fit connection in the pivot lever 33. By means of a press-fit connection, it is achieved an improved friction through a friction layer 50, between the pivot lever 33 and the bearing pin 43. Antitorque elements 53 are formed from extensions of the pivot lever 33 on either side of the pivot lever 33 along the longitudinal direction of the bearing pin 43.
Below, the physical conditions of the vibration damping device are described using the schematic representation of Figure 4. According to Figure 4, the oscillations or vibrations of the tub 13 during operation are introduced in the support element 31 and, through the support element 21, they are transferred along the force line of action f to the pivot lever 33. By means of the pivot lever 33, the vibrations are converted into rotation motion. In this case, the force line of action f of the support element 33 is spaced from the first pivot articulation 37 in an effective lever arm distance I. The effective lever arm distance I is measured perpendicularly to the force line of action and may vary due to vibrations of the tub during operation. As mentioned above, the a support element length a may be many times larger than the pivot lever length b, by means of what a rotation torque at the first pivot articulation is reduced.
Taking into account the tub vibrations caused during operation, the effective lever arm distance I between the support element 31 and the first pivot articulation varies. Due to the increased friction in the first pivot articulation 37, a translational energy of the tub 13 is at least partially converted into friction energy. In this way, vibrations and noise during operation of the drum 11 can be further reduced.
Figure 5 shows the right support element 31 of Figure 4 with the pivot lever 33 in a perspective view. As shown in Figure 5, the bearing bushing 41 of the first pivot articulation 37 is fixedly connected to the housing side 35 via a plate bracket element 45. The pivot lever 33 is attached to a continuous tubular shaped bearing pin 43 fixed in rotation with respect to the pivot lever 33 and rotatably mounted to the bearing bushing 41 where friction layers 50 are arranged and heat is dissipated.
Figure 6 shows the right support element 31 of Figure 5 with the pivot lever 33 in a perspective view. As it is apparent from Figure 3, the bearing bushing 41 of the first pivot articulation 37 is fixedly connected to the housing via a cross plate bracket element 45 which is fixed at both edges of the housing side 35. The bearing bushing 41 is obtained by cutting and folding the cross plate bracket element 45 in such a way that two hugs are formed. The pivot lever is rotatably connected to the bearing bushing 41 via a continuous bearing pin 43 fixed with respect to the bearing bushing 41 in this case, the aforementioned friction layers are arranged in the pivot lever 33.

LIST OF REFERENCES

1: washing machine
3: housing
5: housing front
7: washing machine door
9: load opening
11: drum
13: tub
15: drum rotational axis
17: springs
19: housing ceiling
23: housing base
25: drive motor
27: transmission belt
29: driven pulley
31: support element
33: pivot lever
35: housing side
37: first pivot articulation
39: first pivot axis
41: bearing bushing
43: bearing pin
45: bracket element
47: second pivot articulation
49: second pivot axis
50: friction layer
51: third pivot articulation
53: antitorque element
a: support element length
b: pivot lever length
f: force line of action on the support element
l: effective lever arm distance

Claims

Home appliance, in particular a washing machine (1) or a dryer, with a housing (3), in which a drum (11) is rotatably mounted in a tub (13), the tub (13) being coupled to the housing (3) via at least one support element (31) of a vibration damping device (17, 31, 33) including pivot articulations (37, 47, 51) comprising a first pivot articulation (37); the support element (31) being articulated to the housing (3) via a pivot lever (33) which is articulated to the housing (3), particularly to a housing side (35), via the first pivot articulation (37) about a first pivot axis (39) fixed with respect to the housing (3); characterized in that at least one of the pivot articulations (37, 47, 51) includes a rotational friction damper, and the first pivot axis (39) is above a horizontal plane passing through the lowest point of the tub (13).
Home appliance according to claim 1, wherein the first pivot axis (39) is at a height above a housing base (23) of the home appliance.
Home appliance according to claim 2, wherein a drawer is allocated under the tub (13).
Home appliance according to any of the above claims, wherein the first pivot axis (39) is connected to the housing (3), particularly to the housing side (35), via a bracket element (45) so as to provide rigidity to the housing structure at said connection.
Home appliance according to any of the above claims, wherein the pivot lever (33) is articulated to the support element (31) via a second pivot articulation (47) about a second pivot axis (49) movable with respect to the housing (3).
Home appliance according to any of the above claims, wherein the support element (31) is articulated to the tub via a third pivot articulation (51) about a third pivot axis fixed with respect to the tub (13).
Home appliance according to any of the above claims, wherein at least one of the pivot articulations (37, 47, 51) comprises a bearing bushing (41), in which at least a bearing pin (43) is rotatably connected, the bearing pin (43) being tubular shaped and made of a thermal conductive material, especially of metal, such that friction heat is dissipated through the bearing pin (43).
Home appliance according to any of the above claims, wherein the support element (31) and/or the pivot lever (33) are rigid.
Home appliance according to any of the above claims, wherein a support element length (a) is greater than twice a pivot lever length (b).
Home appliance according to any of the above claims, wherein it comprises a goniometer sensor for obtaining the angle between the pivot lever (33) and the support element (31) during operation of the home appliance so as to allow determination of the position of the third pivot articulation (51) with respect to the housing (3).
Home appliance according to any of the above claims, wherein the vibration damping device comprises at least one antitorque element (53) formed from extensions of the pivot lever (33) on either side of the pivot lever (33) along a longitudinal direction of the bearing pin (43), for preventing the twisting of the pivot lever (33) about its longitudinal axis and/or the turning about an axis perpendicular to the first pivot axis (39).
Home appliance according to any of the above claims, wherein it comprises at least two support elements (31) with at least one support element disposed at either side of the tub with respect to a vertical central plane.