TECHNICAL FIELD

The invention relates to a balancing system for a washing machine and to a method for operating the balancing system of a washing machine.

BACKGROUND

Although applicable to any washing machine comprising a drum, the present invention will mainly be described in conjunction with a washing machine comprising a horizontally rotating drum.

The balancing problem of a washing machine when spinning at high rotational speeds, e.g. during a drying cycle, is one of the most important problems. It is an important criterion that affects the performance of the machine. It is desirable to distribute the laundry in a balanced way in the machine, but this is virtually impossible since the laundry will distribute within the drum in an accidental manner. An unbalanced drum will cause strong vibration if not moving of the washing machine and also produces a lot of noise. Previous solutions to this problem are mainly based on estimations of the imbalance by software and the subsequent correction of this imbalance by various means which may require a relatively high number of trial and error cycles.

Accordingly, there is a need for an improved balancing system which balances the drum in a relatively short time period. SUMMARY OF THE INVENTION

The above stated problem is solved by the features of the independent claims. It is understood, that independent claims of a claim category may be formed in analogy to the dependent claims of another claim category.

Disclosed is a washing machine comprising

- a drum wherein laundry is to be placed,

- a tub wherein the drum moves,

- a motor configured to drive the tub,

- at least one compartment system provided on the wall of the drum comprising

- a pair of compartments, said compartments suitable for storing a liquid, the two compartments of the pair of compartments placed centrosymmetrical with respect to the center of the drum on the wall of the drum, and

- a pipe connecting the pair of compartments with each other,

- a pump configured to pump a liquid from one compartment of the pair of compartments to the second compartment of the pair of compartments and vice versa,

- a first controller connected to the pump of the at least one compartment system and for controlling the pump and positioned on the drum,

- a second controller configured to determine an imbalance of the drum when the drum is rotating and control the activation or deactivation of the pump of the at least one compartment system via the first controller.

The second controller may be configured to:

determine a first imbalance value;

when the first imbalance value is above a predefined imbalance value, control the pump to transfer liquid from one compartment of the pair of compartments to the second compartment of the pair of compartments, and

determine a second imbalance value,

wherein when determining that the second imbalance value is below the first imbalance value and not below the predefined imbalance value, control the pump to continue transferring liquid from one compartment of the pair of compartments to the second compartment of the pair of compartments,

wherein when determining by the second controller that the second imbalance value is above the first imbalance value, control the pump to transfer liquid from the second compartment of the pair of compartments to the first compartment of the pair of compartments, and

wherein when determining by the second controller that the second imbalance value is below the predefined imbalance value, control the pump to stop transferring liquid.

The washing machine may comprise a transmitter connected to the second controller and comprises a receiver connected to the first controller, and the second controller is configured to transfer a control signal via the transmitter to the receiver of the first controller wirelessly.

The washing machine may comprise a power source on the drum configured to provide electrical energy to the first controller and the at least one compartment system, wherein the power source is replaceable and/or wirelessly rechargeable.

The washing machine may comprise at least two of the compartment systems, preferably two of the compartment systems, and all compartments on the drum being equidistant to each other on the wall of the drum and the first controller being connected to each pump of the respective compartment systems.

Each pair of compartments of one compartment system may be connected by a separate pipe and each pair of compartments of one compartment system may form a closed liquid circuit.

All compartments of the compartment systems may be connected by a shared pipe connecting all compartments with each other and the entirety of the compartment systems may form a closed liquid circuit. Disclosed is also a method for controlling the imbalance of the washing machine as defined above, the method comprising, by the second controller, determining an imbalance of the drum when the drum is rotating,

controlling the pump of the at least one compartment system via the first controller.

The method may comprise determining a first imbalance value;

when the first imbalance value is above a predefined imbalance value, controlling the pump to transfer liquid from one compartment of the pair of compartments to the second compartment of the pair of compartments, and

determining a second imbalance value,

wherein when determining that the second imbalance value is below the first imbalance value and not below the predefined imbalance value, controlling the pump to continue transferring liquid from one compartment of the pair of compartments to the second compartment of the pair of compartments,

wherein when determining by the second controller that the second imbalance value is above the first imbalance value, controlling the pump to transfer liquid from the second compartment of the pair of compartments to the first compartment of the pair of compartments, and

wherein when determining by the second controller that the second imbalance value is below the predefined imbalance value, controlling the pump to stop transferring liquid.

Further embodiments of the present invention are subject of the further subclaims and of the following description, referring to the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention and advantages thereof, reference is now made to the following description taken in conjunction with the accompanying drawings. The invention is explained in more detail below using exemplary embodiments which are specified in the schematic figures of the drawings, in which:

Fig. 1 illustrates a washing machine 100 of the present disclosure.

Fig. 2 illustrates a section of the compartment system 105 for a washing machine 100 of the present disclosure.

Fig. 3 illustrates a method for balancing the drum 102 of a washing machine 100 using the compartment system 105 of the present disclosure.

In the figures like reference signs denote like elements unless stated otherwise.

DETAILED DESCRIPTION OF THE DRAWINGS

Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and/or equivalent implementations exist. It should be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration in any way. Rather, the foregoing summary and detailed description will provide those skilled in the art with a convenient road map for implementing at least one exemplary embodiment, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope as set forth in the appended claims and their legal equivalents. Generally, this application is intended to cover any adaptations or variations of the specific embodiments discussed herein.

Figure 1 schematically illustrates a washing machine 100 of the present disclosure. The washing machine 100 comprises a drum 102, into which laundry is to be placed and a tub 103 wherein the drum 102 moves in rotating fashion. A housing 101 of the drum 102 is also illustrated. The view is a view along the rotational axis of the drum 102. The washing machine 100 can be a washing machine 100 with a horizontally moving drum 102 or a vertically moving drum 102, preferably a washing machine 100 with a horizontally moving drum 102. The drum 102 consists of cylindrical wall and a disk-like backside and is open to the front side. The washing machine 100 can comprise a lid (not illustrated) reversibly sealing or closing the tub 103 from the exterior of the housing 101. The tub 103 is sealed from the inside of the housing 101 to prevent liquid from flowing into the housing 101 and connected by conventional tubing 103 to a water inlet and a water outlet (not illustrated).

The washing machine 100 can also comprise a motor 104 for rotatably moving the drum 102 via driving means, i.e. a drive, e.g. by a wheel connected to the backside of the drum 102 and a belt connecting the drum 102 with a drive of the motor 104. The drum 102 may comprise at least one baffle (not illustrated) positioned on the wall, preferably three or five baffles which assist in preventing the laundry from sticking to the inside of the wall of the drum 102 and assist in creating turbulences in the washing liquid comprising the laundry and thus an improved washing efficiency.

The washing machine 100 is equipped with a compartment system 105 for reducing the potential imbalance of a drum 102 of the washing machine 100 as illustrated in figure 1 and also in more detail in figure 2.

The washing machine 100 comprises at least one compartment system 105. The compartment system 105 comprises a pair, i.e. two, compartments 106 suitable for storing a liquid. The two compartments 106 of the pair of compartments 106 placed centrosymmetrical with respect to the center of the drum 102 on the wall of the drum 102, i.e. they are positioned on those sections of the wall of the drum 102 which are opposed to each other. The compartments 106 are firmly affixed to the drum 102 by suitable attachment means, e.g. by welds, screws, etc. The compartments 106 can be made of any suitable fluid-tight material, like e.g. metal or plastic. Each of the compartments may be have the same dimensions and especially be configured to house the same volume.

A pipe 107 (or tubing) fluidly couples the two compartments 106. The pipe 107 is placed on the wall of the drum 102 and is firmly affixed to the drum 102 by suitable attachment means, e.g. by welds, screws, etc. Thus, the pipe 107 is placed circumferentially over the wall of the drum 102. In this way the pipe 107 is prevented from detaching from the drum 102 even when the drum 102 is spinning at high speed. A pipe 107 can be made of any suitable fluid-tight material, like e.g. metal or plastic.

In figure 2 it is illustrated that one compartment 106 is connected to two pipes 107, however, it also possible that the compartment 106 is connected to only one pipe 107.

The compartment system 105 also comprises at least one pump 108 which may be positioned directly at the connection between one compartment 106 and the pipe 107 or at any section of the pipe 107. The pump 108 is bidirectional and thus configured to pump 108 liquid from one compartment 106 of the pair of compartments 106 to the second compartment 106 of the pair of compartments 106 and vice versa, i.e. from the second compartment 106 into the first compartment 106.

Furthermore, the compartment system 105 can be equipped with valves 1 14 regulating the flow between compartments 106 which may be positioned directly at the connection between one compartment 106 and the pipe 107 or at any section of the pipe 107. Preferably, the valves 1 14 are placed at a connection between the compartment 106 and the pipe 107. Due to the valves 1 14 the pump 108 does not prevent the flow of fluid when the pump 108 is turned off and the amount of liquid in the compartments 106 can be maintained without an activated pump 108. Each compartment may be sealable from the remainder of the compartment system by two valves 1 14.

The compartment system 105 is a closed circuit with respect to the liquid contained therein. Thus, regularly no liquid is removed from the compartment system 105 or added. A maintenance valve (not illustrated) which is closed during operation of the washing machine 100 and provides a connection from the compartment system 105 to the space outside the compartment system 105 may be provided. In this way, the liquid may be exchanged, removed or added when required when the washing machine 100 is not operating. The liquid may be any suitable liquid, that is liquid at room temperature. For example, the liquid may be water, distilled water or/and water containing preservatives. Before operation the pipes may be filled completely with liquid and the liquid in each compartment of the compartment system 105 may occupy up to 50 vol./vol. % of the volume of each compartment 106.

Each compartment 106 can also comprise a gaseous exchange means 1 15, e.g. a membrane window 1 15, which is impermeable to the liquid in the compartment system 105, but permeable to air. Due to the gaseous exchange means 1 15 it is possible to modify the amount of liquid within a compartment 106 without producing a pressure drop or rise in the compartments 106 when adapting the amount of liquid in the respective compartments 106.

The gaseous exchange means 1 15 are preferably positioned at section of the wall of the compartment 106 that is close to the wall of the drum 102. During the spinning of the drum 102 this section which is closer to the axial center of the drum 102 will remain free of liquid due to the centrifugal force exerted by the drum 102. Thus, air can transfer through the gaseous exchange means 115 from within the compartment 106 to the outside or vice versa.

Furthermore, a first controller 109 is operably connected to the pump 108 and to the optionally present valves 1 14. The controller can activate or deactivate the pump 108 and can also signal to the pump 108 that it is operating in a normal mode or a reverse mode. The first controller 109 is positioned on the drum 102.

The washing machine 100 may also contain a second controller 1 10 configured to determine an imbalance of the drum 102 when the drum 102 is rotating. The second controller 1 10 may also control the pump 108 of the at least one compartment system 105 via the first controller 109. The second controller is usually not affixed to the drum, but may be positioned in another place within the housing and this is not placed on any moving part.

The imbalance of the drum 102 can be determined by a known system of the art. For example, a sensor maybe mounted on a rotation shaft on which the drum 102 rotates for detecting irregularities involved in rotation of the drum 102. Alternatively or in addition, a vibration sensor (not illustrated) may be placed on the tub 103, e.g. a magnetorestrictive sensor or load cell.

The first controller 109 can thus be operatively connected to sensors configured to determine an imbalance of the drum 102 when the drum 102 is rotating and thus the first controller 109 is configured to determine an imbalance of the drum 102 and control the activation or deactivation of the pump 108 of the compartment system 105 via the first controller 109, for example, by sending an appropriate signal to the first controller 109 which in turn sends an appropriate signal to the pump 108 and optionally the valves 1 14. The connection of the first controller 109 with the pump 108 and/or valves 1 14 is provided by appropriate signaling cables which are fixed to the drum 102, e.g. parallel to the pipe(s) 107.

In particular, the second controller 1 10 may contain a memory comprising a predefined imbalance value, i.e. a threshold value. An imbalance value is a measure of the degree of imbalance determined by the second controller 1 10 and the above described sensors. The imbalance value will depend on the particular imbalance determination system used. For example, in case of the use of a vibrational sensor, a degree of vibration can be determined. A predefined imbalance value is a fixed threshold value that defines beginning with which imbalance value the drum 102 is considered to be imbalanced. The imbalance value may be predefined or present in the memory connected to the second controller 1 10 or may be adapted by the input of a user.

When the drum 102 is rotating the second controller 1 10 can determine whether an imbalance exists by comparing the determined imbalance value with the predefined imbalance value. The determination may only be activated when the rotation of the drum 102 is above a certain rotation threshold, for example, 1000 rotations per minute or any rotation threshold that indicates a spinning mode of the washing machine 100.

The second controller 110 can be configured to: determine whether a first imbalance value is above the predefined imbalance value, and then control the pump 108 to transfer liquid from one compartment 106 of the pair of compartments to the second compartment 106 of the pair of compartments 106. After this step the second controller 1 10 can perform a further imbalance determination and determine a second imbalance value. The second imbalance value is determined after a fixed time period after the determination of the first imbalance value, e.g. 0.5 seconds, 1 second, 1.5 seconds, or up to 10 seconds. The imbalance value may be proportional or inverse proportional to the determined imbalance. While the present disclosure describes an imbalance value is proportional to the determined imbalance, it also disclosed that the imbalance value is inverse proportional to the determined imbalance resulting in an reversed relation of the determined imbalance values.

Dependent on the determined imbalance value different consequences are foreseen:

When determining that the second imbalance value is below the first determined imbalance value, but still not below the predefined imbalance value, the pump 108 is controlled to continue to transfer liquid from the first compartment 106 to the second compartment 106 of the pair of compartments 106.

Alternatively, when determining by the second controller 1 10 that the second imbalance value is above the first imbalance value, i.e. the imbalance of the drum 102 has further deteriorated, the second controller 1 10 controls the pump 108 to transfer liquid from the second compartment 106 of the pair of compartments 106 to the first compartment 106 of the pair of compartments 106, i.e. in the reverse direction. Any valves 1 14 which are closed and may hinder the transport of liquid may be opened to allow the transfer of liquid.

A further (third and further) imbalance value can be subsequently determined, which may result in the above described outcomes or in the following outcome: When determining by the second controller 1 10 that the second imbalance value is below the predefined imbalance value, i.e. the imbalance is now in an acceptable range, the second controller 1 10 controls the pump 108 to stop transferring liquid. Any valves 1 14 which are open and may allow the transfer of liquid may be closed to prevent the transfer of further liquid.

Preferably, the washing machine 100 comprises a transmitter 1 1 1 connected to the second controller 1 10 and comprises a receiver 1 12 connected to the first controller 109, and the second controller 1 10 is configured to transfer a control signal via the transmitter 1 1 1 to the receiver 1 12 of the first controller 109 wirelessly.

The washing machine 100 may further comprise a power source on the drum 102 configured to provide electrical energy to the first controller 109 and the at least one compartment system 105. This power source may be a replaceable and/or wirelessly rechargeable, e.g. via inductive charging.

In a preferred aspect of the disclosure, the washing machine 100 comprises at least two of the compartment systems 105, preferably two of the compartment systems 105. All compartments 106 on the drum 102 may be equidistant to each other on the wall of the drum 102, as illustrated in figure 1 , and the first controller 109 may be connected to each pump 108 and/or valve 114 of the compartment systems 105 by appropriate cabling. Alternatively, the washing machine 100 may comprise further first controller 109s, one for each compartment system 105. The advantage of having two compartment systems 105 consisting of two compartments 106 each is that they will be positioned exactly at 90° to each other with respect to the axis of the drum 102 on the wall of the drum 102. Thus, the imbalance of the drum 102 may be more efficiently reduced. However, it also considered that the washing machine 100 comprises more than two compartment systems 105, e.g. any number between 3-20 to further refine the imbalance control mechanism.

When the washing machine 100 comprises more than two compartment systems 105 the procedure for determining a first and further imbalance value followed by the appropriate activation or deactivation of the pump 108 and/or valves 1 14 for each compartment system 105 may be sequentially for the compartment systems 105 or concurrently until the second or further imbalance value is below the predetermined imbalance value. The procedure for controlling the pumps 108 of the respective compartment systems 105 sequentially may be performed by performing the procedure with no time delay between the successive respective procedures for each compartment system 105.

When the washing machine 100 comprises more than two compartment systems 105 each pair of compartments 106 of one compartment system 105 may be connected by a separate pipe 107 and thus each pair of compartments 106 of one compartment system 105 forms a closed liquid circuit.

Alternatively, all pairs of compartments 106 of one compartment system 105 are connected by a shared pipe 107 connecting all compartments 106 with each other and the entirety of the compartment systems 105 forms a closed liquid circuit. By suitably activating and deactivating of the pumps 108 and/or opening/closing of the valves 1 14 in the closed circuit, liquid may be transferred from one compartment 106 of a first compartment system 105 via another compartment 106 of a second compartment system 105 positioned between the second compartment 106 of the first compartment system 105 while maintaining the amount of liquid in the compartment 106 positioned between by allowing the same amount of liquid to enter and leave the compartment 106 positioned between, by opening the optionally present valves 1 14 limiting access to the compartment 106 in between and/or activating a pump 108 associated with the compartment 106 in between and belong to a second compartment system 105.

Disclosed is also a method for controlling the imbalance of the washing machine 100 as defined above and illustrated in figure 3, the method comprising starting a determination S1 by the second controller 1 10, determining S2 an imbalance of the drum 102 when the drum 102 is rotating, controlling S4 the pump 108 of the at least one compartment system 105 via the first controller 109. The method may further comprise determining S2 a first imbalance value; when the first imbalance value is above a predefined imbalance value S3, controlling S4 the pump 108 to transfer liquid from one compartment 106 of the pair of compartments 106 to the second compartment 106 of the pair of compartments 106, and determining S2 a second imbalance value, wherein when determining that the second imbalance value is below the first imbalance value S3 and not below the predefined imbalance value, controlling S4 the pump 108 to continue transferring liquid from one compartment 106 of the pair of compartments 106 to the second compartment 106 of the pair of compartments 106, wherein when determining S3 by the second controller 1 10 that the second imbalance value is above the first imbalance value, controlling S4 the pump 108 to transfer liquid from the second compartment 106 of the pair of compartments 106 to the first compartment 106 of the pair of compartments 106, and wherein when determining S3 by the second controller 1 10 that the second imbalance value is below the predefined imbalance value, controlling S5 the pump 108 to stop transferring liquid.

Provided is a balancing system for a washing machine 100 and to a method for operating the balancing system of a washing machine 100.

A balancing system for a washing machine 100 and to a method for operating the balancing system of a washing machine 100 is described, wherein a first controller 109 is connected to the pump 108 of the at least one compartment system 105 and for controlling the pump 108 and positioned on the drum 102, and a second controller 1 10 is configured to determine an imbalance of the drum 102 when the drum 102 is rotating and control the activation or deactivation of the pump 108 of the at least one compartment system 105 via the first controller 109. List of reference signs

100 Washing machine

101 Housing

102 Drum

103 Tub

104 Motor

105 Compartment system

106 Compartment

107 Pipe

108 Pump

109 First controller

110 Second controller

111 Transmitter

112 Receiver

113 Drive

114 Valve 114(s)

115 Gaseous exchange means S1-S5 Method steps