The invention relates to a washing machine (this expression including also a washing machine having dryer function), comprising a filter element for a recirculation circuit thereof.
DE 100 46 349 A1 discloses a washing machine having a draining circuit and a recirculation circuit for circulating washing water from a lower portion of a tub to an upper portion thereof. A fine mesh filter is spanned across the inlet of the recirculation circuit to prevent fluff to enter the recirculation circuit. The filter element is cleaned by a backflow of water through the recirculation circuit, wherein removed fluff is washed away by water flowing past the mesh filter during a draining phase.
EP 0 240 911 B1 discloses a removable filter for a washing machine. The washing machine comprises a recirculation circuit and a draining circuit fluidly connected to a tub via a conduit. The filter is placed at the outlet of the conduit such that washing water which is drained from the tub or which is circulated back into the tub passes through the filter.
During a draining phase of a washing cycle the fluff fibers caught at a surface of a fine filter portion of the filter are removed by water flowing past the surface of the fine filter portion.
It is an object of the invention to provide a washing machine comprising an improved filter element for a recirculation circuit.
The invention is defined in claim 1. Particular embodiments are set out in the dependent claims.
In the following, when reference is made to ‘water’, the term ‘water’ may denote water as such, washing water, washing liquid, washing liquor or the like.
In the following, when reference is made to “washing machine”, the term “washing machine” can denote a front-loading type or a top-loading type washing machine, both having or not also a dryer function.
According to claim 1, a washing machine comprises a tub and a draining circuit fluidly connected to the tub for draining water from the tub during at least one draining phase of a washing cycle. E.g. the draining circuit is connected or attached to the tub or the tub may comprise a sump and the draining circuit is attached or connected to the sump. A recirculation circuit is provided, which is fluidly connected to the tub for recirculating fluid from a lower portion of the tub to an upper or middle portion of the tub in at least one recirculation phase of a washing cycle. By recirculating the water repeatedly to the laundry it is not required to use a water level in the tub which is high enough to fully cover the laundry within the tub. Consequently the amount of water to be heated is reduced, whereby the energy consumption of the washing machine is reduced. A filter element of the washing machine is located upstream of an inlet of the recirculation circuit for preventing foreign objects (e.g. fluff, buttons, coins, etc.) to enter the recirculation circuit. Thus a clogging or blocking of the recirculation circuit and/or of a recirculation pump thereof is prevented by the filter element. At least one filter aperture of the filter element to let pass water extends to a lateral border or perimeter (which may be a circumference if the filter has a circular shape) of the filter element. Thus the at least one filter aperture comprises an interrupted perimeter or an opening like a gap in its perimeter. Thereby the at least one filter aperture forms a spacing between at least two filter fingers, or stings forming filter or rake pins. When recirculating water through the recirculation circuit, fluff and other foreign objects are caught in the at least one aperture of the filter element or the at least two fingers of the filter element. When using a mesh filter element as described with respect to DE 100 46 349 or EP 0 240 911 B1, fluff and foreign objects might get entangled in the mesh, such that water flowing past or through the mesh filter cannot remove the entangled fluff any more. In this case the only possibility to clean the mesh filter is to replace it or to clean it mechanically or by hand. In contrast thereto, the opening in the perimeter of the at least one filter aperture or the filter fingers of the filter element prevent that fluff/foreign objects get entangled in the filter element. Thus the opening in the perimeter of the at least one filter aperture or the filter fingers assist in washing away fluff/foreign objects from the filter element, e.g. during a draining phase of the washing machine.
According to a preferred embodiment the filter element extends or protrudes at least partially or with a main section thereof into the draining circuit, the tub, or a sump of the washing machine. Thus the filter element is preferably attached to the washing machine in a cantilevered manner. I.e. only one part of the filter element is advantageously fixed or attached to the washing machine, such that the filter element is a self supporting or free-standing element. Consequently the filter element preferably does not extend across the entire cross-section of the drain circuit or sump of the washing machine. The cantilevered attachment, which results in a free end of the filter element, assists in washing fluff off the filter element into the draining circuit, tub or sump.
Preferably a gap is provided at least over a portion of an area between a lower surface of the filter element and the upper surface of a region below the filter element. This gap assists in washing away deposits and fluff from the filter element and the recirculation circuit when the draining circuit is operated and water is drained out of the washing machine.
In a preferred embodiment the filter element, at least a portion of the filter element, or a main section thereof, is adapted to deflect water flowing from the tub, in particular during a draining phase. Thus the filter element is adapted to redirect the drain water flow. E.g. water flowing from the tub in a draining phase hits the filter element or a portion thereof at an acute angle and is redirected by the filter element in direction to the draining circuit.
Due to the impact of the water on the filter element or the water flowing onto or past the filter element fluff and foreign objects are effectively washed away from the filter element. Alternatively, if the filter element is arranged in the tub, in particular between a tub and a drum rotationally supported in the tub, a water flow in the tub, which may be caused by the rotation of the drum within the tub, flows past the filter element and assists thereby in washing away fluff from the filter element.
Preferably at least a portion of the filter element which is attached to or at the inlet, in particular to the draining circuit, the tub and/or sump, comprises a closed surface. Thus no opening or aperture is provided proximate to an attached portion of the filter element. The closed portion of the filter element can efficiently deflect water e.g. to the draining circuit. A free end of the filter element, which extends into the draining circuit, tub and/or sump preferably comprises the at least one filter aperture. Thus the filter element advantageously comprises a fork-like or rake-like shape, whereby the washing away of fluff from the filter element is facilitated.
Preferably the filter fingers or rake pins are aligned parallel to or are partially extending into a flow direction of water flowing from the tub to the draining pump when the draining pump is operating. Consequently, in a draining phase fluff and foreign objects are washed in direction of the opening in the at least one filter aperture or in direction of the free end of the at least two filter fingers. Thus the washing away of fluff is further facilitated.
Preferably, but not necessarily, the opening in the perimeter of the at least one filter aperture takes up at least 1/16, 1/10, ⅕ or ¼ of the perimeter of the at least one filter aperture. Thereby the gap is sufficiently large to allow e.g. fluff to be readily washed away from the filter element.
According to a preferred embodiment, the at least one aperture comprises a shape which is tapered from the opening in the at least one aperture to a base of the at least one aperture opposite to the opening. Thus the base of the at least one aperture is narrower than the opening in the perimeter of the at least one aperture. Or each of the at least two filter fingers are advantageously tapered from a base to the free end thereof. The narrowing of the cross-section of the at least one aperture in direction to the base of the at least one aperture assists in catching or trapping of fluff and foreign objects in the at least one aperture. In turn, the widening of the cross-section of the aperture from the base to the gap assists the removal or washing away of fluff or foreign objects which are caught in the aperture. For example the at least one filter aperture comprises a shape selected from rectangular, substantially rectangular, triangular, substantially triangular, semicircular or substantially semicircular.
Preferably the filter element comprises at least four filter fingers, preferably at least six filter fingers. However any number of filter fingers (odd or even, but clearly equal to or greater than two) may be provided. The apertures are preferably arranged parallel or substantially parallel to each other, such that the apertures form a rake-like filter element.
According to a preferred embodiment, the washing machine comprises a valve having a valve body arranged between the tub and the draining circuit. When the valve is closed during a heating phase of a washing operation, water within the draining circuit is not heated. Thus the energy consumption of the washing machine is reduced.
In an embodiment the valve body is formed by the sump container or a portion thereof or by a portion of a draining suction duct connecting the tub to a draining pump. Thus the number of elements for providing the valve is reduced as compared to a valve having a separate body. In case the inlet of the recirculation circuit is arranged at a bottom or lower region of the valve body, the recirculation circuit has an improved ability to suck in undissolved detergent that has collected at the lower region of the valve body (e.g. sump or draining suction duct) due to gravity.
Preferably the filter element or the inlet of the recirculation circuit is placed downstream of the valve. In other words, the inlet of the recirculation circuit is positioned, with respect to the flow of water which exits the tub through the valve and goes to the draining circuit, after the valve (i.e. the water exiting the tub meets the inlet of the recirculation circuit after passing the valve). It may occur that undissolved detergent has passed the valve (e.g. during the water filling process when detergent is flushed into the tub) due to a not perfectly watertight sealing of the valve. This detergent collects in the draining circuit substantially below the valve seat around the valve opening in the tub. The next time when the recirculation circuit is operated, the detergent collected in this way below the valve seat will be sucked in through the inlet of the recirculation circuit below (or downstream as seen from the tub) the valve, and is circulated back into the tub. Thereby the washing effect is enhanced, as detergent is more efficiently used instead of being drained from the washing machine. In other words less detergent gets lost in the draining circuit of the washing machine and therefore less detergent has to be used to achieve the same washing result. Thus the washing machine provides an economical washing operation with respect to energy and detergent consumption.
Preferably the valve body has the valve seat and a movable closure element adapted to be releasable engaged with the valve seat for closing the valve opening through the valve seat. The valve is preferably automatically closed or opened in dependency of a water level in the draining circuit and/or tub. In other words the valve is preferably adapted to be self-actuated in dependency of a water level, for example by a closure element which is adapted to float in or on the (washing) water. E.g. the closure element floats on the water gradually filling the draining circuit or sump and is eventually pressed towards the valve seat by the rising water level, i.e. by buoyant force, and seals thereby the valve opening in the valve seat. Thereby the tub is shut off from the draining circuit, wherein a simple and robust valve is provided which is maintenance-free or substantially maintenance-free.
According to a preferred embodiment a surface of the filter element facing the valve is shaped to receive or support the movable closure element of the valve on or at the surface.
In a preferred embodiment the filter element partially or totally receives the closure element on its surface when water level is low and when the closure element is not longer buoyant on the water or is pressed down by flowing water. Due to the water flowing past the closure element a (mainly rotational) movement of the closure element occurs on or above the filter element, wherein a vortex is created which helps in removing fluff or other foreign objects from the filter element.
Preferably the movable closure element has a spherical or substantially spherical shape, such that it is adapted to engage with the valve seat in any (rotated) position. This is advantageous when the closure element is freely floating within the sump or draining circuit. Alternatively the closure element is formed e.g. by a hinged flap, e.g. like in a swing check valve, which is closed by buoyant force and water pressure.
However other kind of valves (e.g. electrically controlled) may be used for allowing/impeding water to flow from the tub to the draining circuit.
According to a preferred embodiment the filter element comprises, in at least one cross-section plane, a totally or partially arched or bent or hemispherical cross-section, and/or it is totally or partially concave in drain flow direction or as seen from the tub side. E.g. the filter element comprises a bowl-like form which assists in catching foreign objects and/or in supporting the movable closure element.
According to an alternative embodiment of a washing machine according to the invention, the inlet of the recirculation circuit, for example a pipe thereof, is attached to a lower portion of the tub, i.e. upstream the valve. Thus the filter element, which is located upstream the inlet, in this case advantageously extends into the tub, in particular into a space between the tub and a drum of the washing machine mounted therein. Also in this embodiment the filter element is cleaned by the water flowing past the filter element during the at least one draining phase of a washing cycle. Additionally, a rotational movement of the drum causes a flow or stream of washing water past the filter element in the tub and assists thereby in washing fluff or foreign objects from the filter element.
For the embodiments of the washing machine each isolated feature of the claims or description can be added or any arbitrary combination of isolated or individual features can be added to the claims.
Reference is made in detail to preferred embodiments of the invention, examples of which are illustrated in the accompanying figures, which show:
a-d perspective views and cross sectional views of a valve as shown in
a-d perspective views of a filter element as shown in
a-b a perspective view of an alternative embodiment of a filter element and a sectional side view of a valve with such a filter element, and
a-b a perspective view of another embodiment of a filter element and a sectional side view of a valve with such a filter element.
In a heating phase of a washing cycle the water in the tub 2 is advantageously heated by a heating element (not shown) arranged in the tub. When the valve 26 is closed, only the water in the tub 2 is heated but not the water in the draining circuit 16, whereby the energy consumption of the washing machine is reduced.
A recirculation circuit 10 is provided to circulate water or washing water from a lower portion of the tub 2 to an upper portion of the tub 2 (as in the embodiment shown), or to a middle portion of the tub. The recirculation circuit 10 preferably comprises a suction pipe 13 preferably fluidly connected to the draining suction pipe 17 (forming the sump), a recirculation pump 12 and a recirculation pipe 11. When the recirculation pump 12 is operated, the laundry 44 in the tub 2 is efficiently wetted without having to provide an amount of water in the tub 2 which completely (or even partially) covers the laundry 44. I.e. on the one hand the water consumption during a washing cycle is reduced and on the other hand, due to reduced water consumption, less water has to be heated, whereby the energy consumption is reduced.
The recirculation pump 12 and the draining pump 18 may be not watertight. Thus the water level in the recirculation pipe 11 and the draining riser pipe 19 corresponds to the water level in the tub 2 or draining suction pipe 17 when the pumps 12 and 18 are not operated and the valve 26 is open.
A filter element 28 is advantageously arranged downstream the valve seat 22 in front of an inlet 14 of suction pipe 13 of the recirculation circuit 10. When the recirculation pump 12 is operated, the water passes the filter element 28 before it enters the recirculation circuit 10. The filter element 28 prevents that fluff and foreign objects which may pass through the opened or partially opened valve 26 enter the recirculation circuit 10, where they might obstruct a nozzle at the outlet of the recirculation pipe 11 or the recirculation pump 12. When no water is in the draining circuit 16, and/or when the recirculation pump 12 is operated and/or when the water level is low, the movable closure element 24 rests on the bottom of the valve body 27 and/or on the filter element 28.
The valve 26 provides a simple and robust way for automatically shutting off the tub 2 from the draining circuit 16 during those phases of the washing cycle, in which the pumps 12, 18 are not operated and in which the water level has a minimum height to press the movable closure element 24 against the valve seat 22. In particular the valve 26 is preferably closed during a heating phase when the water is filled to close the valve and when no pumps are operated.
It may happen that detergent, in particular powder detergent, is not completely dissolved at the beginning of a washing cycle. For example at the beginning of flushing in the detergent by flowing tap water through the detergent drawer 8 and before the water level is high enough to close the valve 26 (see e.g. water level 42a), some detergent may remain undissolved and can be flushed along the tub inner wall through the opening in the seat 22 into the sump or draining suction pipe 17. There it may collect due to gravity. Additionally, even if the water level is high enough to close the valve 26, undissolved detergent collecting at the lowest point of the tub 2 may enter the draining circuit if valve 26 not perfectly closes the opening in the seat 22. E.g. during drum rotation operation of the washing machine.
As indicated in
Advantageously both the suction pipe 13 and the draining suction pipe 17 have sections formed as a bellows. The bellows serve for damping vibrations of the tub from being transferred to the pumps 12, 18.
a-d depict perspective, cross sectional views of the valve 26 as shown in
Preferably, a further opening 37 (shown in
b shows a cross sectional view of the valve 26 along line A-A of
The filter element 28 is preferably attached to the lug 29 forming the inlet 14 in a cantilevered manner, such that the main body of the filter element 28 extends into inner volume of the valve body 27 in a free-standing manner. A portion of the filter element 28 facing the inner space of the valve body 27 preferably has a shape which corresponds or basically corresponds to the shape of the movable closure element 24; for example, if the movable closure element 24 is spherical, the filter element 28 advantageously comprises a bent and/or hemispherical shape which substantially corresponds or partially corresponds to the shape of the movable closure element 24.
d shows a cross sectional view from below along the line B-B shown in
a-d show perspective views of the filter element 28 as shown in
b shows the filter element 28 from below, i.e. it shows the surface 32 of the filter element 28 which faces away from the movable closure element 24 or valve 26. As described above, the filter element may advantageously be part of the lug 29 which forms at the same time a mounting portion for mounting the filter element 28 in the opening of the valve body 27. Thereby the filter element 28 is supported on one side in a cantilevered manner and the main body of the filter element 28 projects into the inner space of the valve body 27. The outer surface of the filter element 28 faces a portion of the inner surface of the valve body 27 and the filter element 28 is preferably arranged such that there is a gap 33 between the outer or lower surface 32 of the filter element and the inner surface of the valve body.
c shows a side view of the filter element 28, wherein an arrow depicts the flow of water during a recirculation phase of a washing cycle.
The arrows in
a shows a further embodiment of a filter element 28′ in a perspective view. Similar or the same numerals are used for similar or the same elements as described above. In contrast to the above described filter element 28, the filter fingers 35a′-d′ of
a shows a perspective view of just another embodiment of a filter element 28″. Similar or the same numerals are used for similar or the same elements as described above.
In contrast to the above described filter elements 28, 28′, filter element 28″ comprises filter fingers 35a″-f′ which are extending from a preferably substantially circular main body having a closed surface. The filter fingers 35a″-f′ are formed preferably straight, i.e. not concave or curved, similarly as described with respect to filter 28′ of
Number | Date | Country | Kind |
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10192058.5 | Nov 2010 | EP | regional |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP11/70494 | 11/18/2011 | WO | 00 | 11/27/2013 |