CN107849785B

CN107849785B - Household appliance for treating laundry, comprising an imbalance compensation device with an electromagnet, and method for operating the same

Info

Publication number: CN107849785B
Application number: CN201680041962.9A
Authority: CN
Inventors: K·派泽特; J·斯格里派克; A·瓦尔特
Original assignee: BSH Hausgeraete GmbH
Current assignee: BSH Hausgeraete GmbH
Priority date: 2015-07-16
Filing date: 2016-06-29
Publication date: 2020-04-28
Anticipated expiration: 2036-06-29
Also published as: PL3322847T3; EP3322847A1; EP3322847B1; WO2017009048A1; CN107849785A; DE102015213348A1; TR201906624T4; RU2683362C1

Abstract

The invention relates to a household appliance (1) for caring for laundry (31), having at least one laundry drum (3) for receiving the laundry (31) and having at least one imbalance compensation device (13, 14) which is arranged on the laundry drum (3) and which has a housing (18, 21) in which a plurality of compensation elements (20, 23, 27, 29, 32, 33) are movably contained, wherein at least some of the compensation elements (20, 23, 27, 29) are ferromagnetic or permanent-magnetic, and the imbalance compensation device (13, 14) comprises at least one holding device (26, 30) which is rotationally coupled to the laundry drum (3), wherein the holding device (26, 30) comprises an electromagnet (42) which is designed to generate a magnetic field, the magnetic field causes a magnetic holding force between the electromagnet (42) and the magnetic compensation element (20, 23, 27, 29). The invention also relates to a method for operating a household appliance (1).

Description

Household appliance for treating laundry, comprising an imbalance compensation device with an electromagnet, and method for operating the same

Technical Field

The invention relates to a household appliance for the care of laundry, having at least one laundry drum for receiving the laundry and having at least one unbalance compensation device which is arranged on the laundry drum and which has a housing in which a plurality of compensation elements are movably contained. The invention further relates to a method for operating a household appliance.

Background

During the washing process of a washing machine, it is known that the laundry is randomly and unevenly distributed in the laundry drum. This results in an imbalance which causes relatively large mechanical vibrations of the laundry drum and at the same time also large mechanical loads of the entire household appliance. On the one hand, the resulting vibrations produce a noise that is uncomfortable for the user; on the other hand, this may also lead to mechanical loading of the floor covering on which the household appliance is placed.

In order to prevent or at least strongly reduce vibrations of the laundry drum during operation of the washing machine, it has already been proposed in the prior art to fasten an annular imbalance compensation device (also known under the name "balancer") to the laundry drum. Such unbalance compensators have an annular, hollow housing in which a compensating mass is located, which compensating mass is provided, for example, in the form of a plurality of spherical compensating elements. The compensating mass is movably mounted inside the housing and, in the supercritical operation of the washing machine, tends to move to the side opposite the unbalanced mass (with respect to the diameter of the laundry drum) in order to thus generate a counterweight for the unbalanced mass and thus to achieve a balance overall.

To this end, WO 2014/116007 describes a balancer for a washing machine, which comprises a compensating housing connected to the laundry drum of the washing machine. An annular channel is defined in the compensation housing, in which annular channel at least one mass is movably arranged. Furthermore, magnets are provided to limit the movement of the mass inside the channel.

Disclosure of Invention

The invention aims to provide the following steps: an improved unbalance compensation of the laundry drum is sought to be achieved with respect to the prior art.

According to the invention, this object is achieved by a household appliance and a method for the care of laundry according to the invention.

The household appliance for care of laundry according to the invention comprises a laundry drum for receiving laundry. Furthermore, the household appliance comprises at least one unbalance compensation device which is arranged on the laundry drum and which has a housing in which a plurality of individual compensation elements are movably contained or arranged. Furthermore, at least some of the compensating elements are ferromagnetic or permanent-magnetic, and the unbalance compensating device comprises at least one holding device which is rotationally coupled with the laundry drum. The unbalance compensation device can comprise not only permanent but also ferromagnetic compensation elements. The holding device comprises an electromagnet which is designed to generate a magnetic field which causes a magnetic holding force between the electromagnet and the magnetic compensation element. Ferromagnetic compensation elements also include compensation elements that: the compensation element comprises non-ferrous materials such as nickel, provided that these non-ferrous materials comprise ferromagnetic properties.

The household appliance for the care of laundry can be, for example, a washing machine or a laundry dryer. The household appliance comprises a laundry drum in which laundry can be placed. Furthermore, an unbalance compensation device is provided, which is arranged or fixed on the laundry drum. The imbalance compensation device has a housing in which a plurality of compensation elements are arranged. The compensation element is movable in the interior space of the housing. By moving the compensating element within the housing, possible imbalances due to an uneven distribution of the laundry in the laundry drum can be reduced in the supercritical rotational speed range.

It is now provided according to the invention that at least some of the compensation elements are ferromagnetic or permanent-magnetic, and that the unbalance compensation device comprises at least one holding device. The holding device is connected in particular to the laundry drum in a rotationally fixed manner. The holding device comprises at least one electromagnet, by means of which a magnetic holding force can be provided for holding the magnetic compensation element. Thus, for example, it is possible to realize: at least some of the magnetic compensation elements are held in a predetermined position inside the housing by means of electromagnets. It can also be provided that the imbalance compensation device comprises a plurality of holding devices, by means of which a predetermined number of magnetic compensation elements can be held in each case on a defined or predetermined area. In contrast to known solutions, in which permanent magnets and ferromagnetic elements are used, electromagnets are to be inserted into the imbalance compensation device or balancer. The electromagnets may comprise, for example, respective coils which, when energized, generate a magnetic field. The magnetic field causes a magnetic interaction between the electromagnet and the magnetic compensation element. By using an electromagnet, the magnetic holding force can be adjusted as desired. The electromagnet is completely force-free, for example after switching off, so that there is no restriction on the freedom of movement of the compensation element. Furthermore, the electromagnet can be mounted in or on the housing of the imbalance compensation device at any arbitrary location.

The magnetic compensation element and the electromagnet are preferably designed with such a magnetic holding force relative to each other that the compensation element is released from the holding device only at a predefined reference rotational speed of the laundry drum. In other words, a defined holding force can be realized or configured relative to one another between the magnetic compensation element and the holding device. In this case, the defined magnetic holding force is specifically set and configured in such a way that the release of the compensating element from the electromagnet or the holding device only takes place when a predetermined reference rotational speed of the laundry drum is exceeded. In this case, the imbalance compensation device is preferably designed such that the magnetic holding force is released at a reference rotational speed of the laundry drum which can be between the minimum rotational speed and the maximum rotational speed of the laundry drum. Thereby realizing that: the compensating element is magnetically coupled to the holding device and is thus fixed in position or in a manner fixed to the rotor in a synchronous rotation within a rotation speed range from a minimum rotation speed of the laundry drum up to a reference rotation speed. This magnetic holding force is also automatically released only when the laundry drum rotates at a rotational speed greater than the reference rotational speed, since the centrifugal force is greater than the magnetic holding force. At such reference rotational speeds, the compensation element can be rotated relative to the holding device or can be rotated in the housing, for example, in a ring-shaped housing, as the magnetic holding force is released automatically. Thus, a desired compensation of imbalances due to an uneven distribution of laundry in the laundry drum can be achieved. In this case, too, it is achieved that even at low rotational speeds, the generation of undesirable noise caused by the compensating element moving relative to the housing of the imbalance compensator is already prevented. This is particularly advantageous in the following cases: until a rotational speed range is reached in which such a change in the movement relative to the housing is effected, which rotational speed range is greater than the resonance range or the resonance frequency of the movement of the laundry drum.

The resonance range of the laundry drum or the resonance frequency of the movement of the laundry drum is understood here to mean the frequency range, in particular the range of the first main eigenfrequency, of a unit arranged in a housing of a household appliance for care of laundry in an oscillating manner, which is located in the range of the main eigenfrequency, in which the laundry drum is rotatably mounted. The main eigenfrequencies of a system that can vibrate are also referred to as modal frequencies. A supercritical rotational speed is also understood to mean a rotational speed of the drum whose rotational frequency lies above the resonant frequency of the movement of the laundry drum. Accordingly, a subcritical rotational speed is a drum rotational speed having a rotational frequency below the resonance frequency of the laundry drum movement.

In order to provide a defined magnetic holding force, the electromagnet can be dimensioned accordingly. The electromagnetic force provided by the electromagnet can be adjusted, for example, by the size or number of turns of the outer portion of the electromagnet. Furthermore, the magnetic force can be adjusted by means of a current flowing through an electromagnet or a coil. In this case, the magnetic holding force is adjusted in such a way that the magnetic holding element is released from the holding device if the washing drum exceeds a reference rotational speed.

According to one specific embodiment, the holding device has a control device which is designed to determine the rotational speed of the laundry drum and to control the current flowing through the electromagnet as a function of the determined rotational speed of the laundry drum. In other words, it can be provided that the release of the compensating element from the retaining device is actively controlled. For this purpose, the control device can control the current flowing through the electromagnet or the coil of the electromagnet. For this purpose, the control device can control the respective switch, for example. The control device is also designed to control the current rotational speed of the laundry drum. For this purpose, the control device can use rotational speed information which is present in the appliance control device itself, for example. The control device can therefore switch off the energization of the electromagnet when the reference rotational speed is reached. Due to the switching off of the current, the magnetic holding force drops after a limited time and the compensating element is released from the holding device. In this way, the unbalance compensation device can be operated as desired.

It is also generally conceivable to transmit a shut-down signal to a control device, which therefore inhibits the current flow through the electromagnet. Such a switch-off signal can be transmitted, for example, wirelessly to the control device. Furthermore, it is also conceivable to use a centrifugal force switch instead of a control device which actively controls the current through the electromagnet or coil. The centrifugal force switch can be designed in particular to open a circuit for supplying the electromagnet with electrical energy when a reference rotational speed is reached.

In a further embodiment, the holding device has an electrical energy store for supplying the electromagnet with electrical energy. The electrical energy store is in particular designed to be rechargeable. The electrical energy store may comprise, for example, a suitable capacitor and/or accumulator. The energy store is a component of the holding device and is arranged on the unbalance compensation device or the drum in a co-rotating manner. The electric energy accumulator can reliably supply electric energy to the electromagnet.

Furthermore, it is advantageous if the electrical energy store has a predetermined discharge characteristic which describes a change over time in the voltage supplied by the electrical energy store. In order to release the compensating weight at the reference rotational speed, this discharge characteristic can be used in a targeted manner, since the current occurring through the electromagnet is proportional to the holding force. For this purpose, the electrical energy store can be dimensioned accordingly. In addition, it can be provided that the charging state of the electrical energy store is adjusted accordingly in the stationary state of the laundry drum, so that the compensating element is released when the laundry drum is subsequently rotated at the reference rotational speed.

The electrical energy store is preferably designed to supply at least one further electrical component of the household appliance, in particular an electrical component rotating together with the laundry drum, with electrical energy. The electrical energy store can also be used to supply further electrical components of the household appliance with electrical energy. In particular, an electrical component can be supplied which rotates together with the laundry drum. These components may be, for example, sensors or sensor-type systems. The component may for example be used for temperature measurement and/or comprise a camera. The electrical component may also be a light emitting element (e.g., a light emitting diode) or a design element.

Preferably, the holding device comprises a receiving coil into which electrical energy can be coupled and which is electrically connected with the electrical energy store. The electrical energy store can be supplied with energy or charged by means of the receiving coil. Energy can be transferred into the receiving coil in the vicinity, in particular wirelessly. This energy transfer can be carried out in such a way that an alternating voltage is generated in the receiving coil. Furthermore, a corresponding rectifier can be connected between the receiving coil and the electrical energy store in order to rectify this alternating voltage. The electrical energy store can thus be supplied or charged with a dc voltage.

Preferably, the household appliance comprises a first charging device, wherein the first charging device has a first transmitting coil for inductively transmitting electrical energy to the receiving coil of the holding device. The transmitting coil or the first charging device can be arranged, for example, in a washing liquid container of the household appliance. In this case, the transmitting coil can be acted upon by an alternating current, which causes an alternating field. By means of such an alternating field, an alternating voltage can be generated by induction in the receiving coil of the holding device. This alternating voltage drives an alternating current, which can be used to charge an electrical energy storage device. Thus, the charging of the energy storage of the holding means can be achieved in a simple manner.

In a further embodiment, the transmission coil is designed to inductively transmit electrical energy to the receiving coil if the laundry drum is in a stationary state and the transmission coil is arranged in a predetermined position with respect to the receiving coil. When the laundry drum is stopped and therefore the unbalance compensation device is also stopped, an inductive energy transfer between the transmission coil and the receiving coil can take place. In this case, it can be provided, in particular, that the laundry drum is brought to a standstill in such a way that the transmitting coil and the receiving coil are aligned with one another. For this purpose, the drive motor can also control the laundry drum in such a way that the transmitter coils are aligned with the receiver coils in the stationary state of the laundry drum. Thus, the electrical energy store of the holding device can be charged efficiently in the stationary state of the laundry drum.

In a further embodiment, the household appliance has a second charging device, wherein the second charging device has at least one magnetic element, relative to which the laundry drum can be rotated and which is designed to generate a dc magnetic field. The second charging device can, for example, be arranged fixedly on the household appliance, so that the laundry drum and the unbalance compensation device can be moved relative to the second charging device. The at least one magnetic element can be, for example, a permanent magnet or an electromagnet operated with direct current. At least one magnetic element provides a dc magnetic field. The dc magnetic field can be used to transfer energy to a receiving coil of the holding device.

Preferably, the at least one magnetic element is designed such that, when the laundry drum is moved relative to the second charging device, a voltage is induced in the receiving coil as a result of the dc magnetic field. At least one magnetic element constitutes a direct current field, which is comparable to a permanent excitation field. When the laundry drum or the holding device with the receiving coil is moved relative to the at least one magnetic element, an arrangement known from generators results. Here, at least one magnetic element provides the excitation and the receiving coil serves as an armature winding. When the laundry drum rotates, the receiving coil acquires a voltage induction caused by the fixed magnetic element, which is dependent on the rotational speed. This voltage in turn drives an alternating current which, after rectification, can be used to charge an electrical energy store. Thus, the electric energy store can also be charged during the rotation of the laundry drum.

In the stationary state of the laundry drum, the electrical energy store cannot be charged by means of the second charging device. This can lead to the energy store not being sufficiently charged when the laundry drum is started, using only the second charging device, and thus not being able to provide a sufficient magnetic holding force by means of the electromagnet. It is therefore preferably provided that the household appliance comprises both the first charging device and the second charging device. When the second charging device is embodied as an electromagnet, the first charging device and the second charging device can also be combined to form a coil system which, depending on the operating situation, is operated with alternating current or direct current. In the stationary state of the laundry drum, the electric energy accumulator can be charged by means of the first charging device. When the laundry drum is started, the second charging device is used. Thus, the electrical energy store can be charged at any time during operation of the domestic appliance.

In one embodiment, the control device of the holding device is designed to detect a voltage induced in the receiving coil and to determine the rotational speed from the detected voltage. When the electric energy accumulator is charged by means of the second charging device, the voltage generated in the receiving coil by induction depends on the rotational speed of the laundry drum. The current rotational speed of the laundry drum can thus be determined by means of the control device from the voltage generated by induction. In this way, the current rotational speed of the laundry drum can be determined in a simple and reliable manner.

In another embodiment, the electromagnet comprises an air coil. That is, the electromagnet or the coil system can be designed as an air coil without a ferromagnetic yoke. Without a ferromagnetic yoke, it is ensured that the electromagnet does not provide a force action when the current through the coil is interrupted. Furthermore, the air core coil is characterized in that it can be produced simply and inexpensively.

According to an alternative embodiment, the electromagnet comprises a coil and a core arranged at least partially inside the coil. In other words, the electromagnet may be configured with a ferromagnetic yoke. In this way, a form of pretensioning can be achieved, which acts as a force on the compensating element even in the switched-off state of the electromagnet. In addition, the electromagnet, which usually has a yoke and/or a core, can be constructed in the same construction space in a much more efficient manner, since the leakage flux fraction and the magnetic resistance are significantly smaller.

In one embodiment, it is provided that the magnetic compensation element is at least partially designed as a permanent magnet. The magnetic compensation element can in particular have a permanent-magnetic core which is surrounded by a housing, in particular a housing made of plastic. The permanent magnet compensation element has the advantages that: the compensating elements, after being released from the holding device, attract each other and thus form a compact block or chain. Thereby, the risk of noise generation due to the compensation elements colliding with each other is reduced. In this case, it may also be provided that at least two non-magnetic compensation elements are provided in the compensation element. Thus, for example, it can be achieved that the compensation elements can be divided into two groups or chains.

According to a further embodiment, the magnetic compensation element is at least partially designed as a ferromagnetic body. The ferromagnetic compensation weight usually has a greater density than the permanent-magnetic compensation weight. In order to compensate for comparable imbalances, fewer compensating elements are therefore required, given the same volume of the individual weights. In this case, it may additionally be provided that a damping element or a damping fluid is arranged inside the housing. Such damping fluid may be, for example, oil. In this way noise can be reduced.

The housing of the imbalance compensation device preferably has a wall of the housing which is closest to the axis of rotation and is thus radially inside, which wall delimits a cavity in which the compensation element is located. In this wall, a recess or recess is formed, which extends in the circumferential direction about the axis of rotation and is formed towards the axis of rotation. The recess can also be formed in a radially oriented side wall of the housing.

The recesses are preferably designed as mechanical separating barriers for separating the entire group into individual groups of compensating elements. This is done in particular in such a way that the non-magnetic compensation element is caught in the recess and thus the separation of the entire group takes place. This is particularly the case when the nonmagnetic interaction-compensating element is lighter and/or larger than the magnetic interaction-compensating element, since the centrifugal force of the nonmagnetic interaction-compensating element is smaller than the centrifugal force of the magnetic interaction-compensating element, in particular at a specific rotational speed of the laundry drum, so that the nonmagnetic interaction-compensating element sinks at least partially into the recess during the circulating operation and then in particular catches on the step-shaped end of the recess. Thereby pulling apart the entire group to some extent. Preferably, the retaining means is arranged in the recess. In this way, the group of compensation elements is preferably also held in a partially embedded manner, so that in addition the fixed position is also stabilized in the circumferential direction about the axis of rotation.

The invention relates to a method according to the invention for operating a household appliance for care of laundry, having at least one laundry drum for receiving laundry and at least one imbalance compensation device, which is arranged on the laundry drum and has a housing in which a plurality of compensation elements are movably contained. At least some of the compensating elements are magnetic, and the unbalance compensating device comprises at least one holding device which is coupled in rotation with the laundry drum and has an electromagnet, wherein a magnetic field is generated by means of the electromagnet, which magnetic field causes a magnetic holding force between the electromagnet and the magnetic compensating element.

Advantageous embodiments of the household appliance according to the invention can be considered as advantageous embodiments of the method, wherein for this purpose the respective specific features carry out the method steps individually or in operative connection.

An unbalance compensation device is understood here to mean a device which is designed to compensate for and thus prevent an unbalance of the laundry drum. The imbalance compensation device may have a compensation mass (for example in the form of a plurality of spherical elements) movably arranged in the housing. Such unbalance compensation devices may also be referred to as "Ball balancers". The at least one imbalance compensation device is in particular designed as a ring and has a housing which is in particular designed as a ring.

By the statements "above", "below", "front", "rear", "horizontal", "vertical", "depth direction", "width direction", "height direction" and the like, the position and orientation of the appliance are explained which result when the appliance is used as intended and is placed as intended and when an observer stands in front of and looking towards the appliance.

Further features of the invention emerge from the figures and the description of the figures. The features and feature combinations mentioned above in the description and the features and feature combinations mentioned below in the description of the figures and/or shown in the figures individually can be used not only in the respectively stated combination but also in other combinations or individually without departing from the scope of the invention. Thus, embodiments which are not shown and explained in detail in the drawings, but which are obtained and produced by means of the combination of the sorting features of the embodiments explained, are also to be considered as being included in the invention and disclosed by the invention. Consequently, embodiments and combinations of features of the independent claims not originally presented are also to be regarded as disclosed.

Drawings

Embodiments of the invention are explained in detail below on the basis of schematic drawings. The figures show:

fig. 1 is a schematic front view of an embodiment of a household appliance for care of laundry according to the invention;

fig. 2 shows a sectional view of a region of an assembly with a laundry drum and an unbalance compensation device according to an embodiment of the invention in a schematic illustration;

fig. 3 is a front view of an embodiment of an unbalance compensation device of a household appliance according to fig. 1 and 2 in an operating state in which the rotational speed of the laundry drum is less than or equal to a reference rotational speed;

FIG. 4 is a front view of an embodiment of the unbalance compensation device of the household appliance according to FIG. 3 in an operating state in which the rotational speed of the laundry drum is greater than a reference rotational speed;

FIG. 5 another embodiment of an imbalance compensation apparatus;

FIG. 6 is a circuit of a holding device of the unbalance compensation device; and

fig. 7 is a graph depicting the voltage of the energy storage of the holding means as a function of time.

In the figures, identical or functionally identical elements are provided with the same reference signs.

Detailed Description

Fig. 1 shows a simplified front view of a household appliance 1 for the care of laundry, which can be, for example, a washing machine or a washer-dryer. The household appliance 1 comprises a housing 2 in which a laundry drum 3 is arranged in a vibrating manner relative to the housing 2 and is rotatably mounted. In this embodiment, the longitudinal or rotational axis a (fig. 2) of the laundry drum 3 is oriented perpendicular to the image plane in the illustration of fig. 1. The longitudinal or rotational axis may also be arranged obliquely to an axis perpendicular to the image plane. Furthermore, in an alternative, not shown embodiment of the domestic appliance, the axis of rotation may be a vertical axis.

Furthermore, the household appliance 1 comprises a washing liquid container 4, which is also arranged in the housing 2 and surrounds the laundry drum 3. In this embodiment, the vibrating arrangement of the laundry drum is achieved by fixing the washing liquid container 4 to the housing 2 by means of springs and dampers, not shown. Alternatively, an arrangement different from the oscillating arrangement of the laundry drum in the washing liquid container is also possible. The laundry drum 3 comprises a hollow-cylindrical outer casing and a rear end wall and is furthermore open on the front side, so that a loading opening is provided here, through which the laundry can be loaded into the interior 5 of the laundry drum 3. The charging opening can be closed by a door 6, which is movably arranged on the housing 2.

In fig. 2 a vertical sectional view is shown, in turn a view in a sectional plane with respect to the y-z plane. A laundry drum 3 with a hollow cylindrical outer casing 7 is shown. The charging opening 8 is also shown. The laundry drum 3 has a star-shaped carrier 10 adjacent to the rear wall or rear end wall 9, which is fixedly connected to the laundry drum 3. The spider 10 is connected in a rotationally fixed manner to a shaft 11, wherein the shaft 11 is driven by a drive motor, not shown, so that the laundry drum 3 is caused to rotate about the axis of rotation a.

During operation of the household appliance 1 and thus during rotation of the laundry drum 3, the loaded laundry can rest on the inner side 12 of the housing 7 in an asymmetrically distributed manner about the axis a, so that an imbalance can occur during rotation of the laundry drum 3. In order to counteract this imbalance or to compensate for it, in the embodiment shown the household appliance 1 comprises two imbalance compensation means 13 and 14. As can also be seen, a plurality of synchronizers are arranged on the inner side 12, wherein only the synchronizers 15 are visible in fig. 2.

Viewed in the direction of the axis a, the front unbalance compensation device 13 is arranged in a front region 16 of the laundry drum 3 and in particular of the housing 7, while the second unbalance compensation device 14 is arranged in a rear region 17.

The first imbalance compensation device 13 is configured as a circumferentially closed ring which is rotationally symmetrically oriented about the axis a. The first imbalance compensation device 13 comprises a ring-shaped housing 18, which in the sectional illustration in fig. 2 has a quadrangular cross section, for example, but which can also have another shape, for example a D-shape. The housing 18 has a cavity 19 in which one or more compensating elements 20 are movably arranged relative to the housing 18. In the illustrated embodiment, the compensating element 20 may be a ball. Additionally or alternatively, a liquid medium, such as oil or water, can also be arranged in the cavity 19.

The second unbalance compensation device 14 is also of corresponding design, which likewise has a correspondingly designed housing 21, a cavity 22 located in the interior in this connection, and particularly preferably a plurality of individual compensation elements 23, which are balls, which are movable in the cavity 22 relative to the housing 21.

The

unbalance compensation devices

13 and 14 are each mounted in a circumferential receptacle 24.

Fig. 3 shows a simplified front view of the components of the imbalance compensation device 13. The imbalance compensation device 14 is preferably identically constructed. Here, a housing 18 is visible, in the hollow space 19 of which a plurality of compensating elements 20 are arranged. The compensating elements 20 are all constructed at least magnetically interactive, only some of which are provided with reference numerals for the sake of clarity. In the exemplary embodiment, it is provided that at least some of the compensation elements 20 are magnetic and thus are designed as permanent magnets, in particular permanently, at least in some areas.

Fig. 3 shows a situation in which the laundry drum 3 rotates about the axis a at a rotational speed which is less than or equal to the reference rotational speed. The reference rotational speed is greater than the rotational speed corresponding to the resonance range of the laundry drum 3 and less than the maximum rotational speed of the laundry drum 3. In the exemplary embodiment described, in such a lower or low rotational speed range up to the reference rotational speed, the first group 25 of compensation elements 20 magnetically interacts with the first holding device 26 independently thereof. The first retaining device 26 may (as explained in detail below) provide a magnetic retaining force. In this case, the shaping is preferably adapted to the housing 18. As can be seen in fig. 3, the holding device 26 extends in the azimuth direction and thus in the direction of rotation about the axis a over a length which corresponds to the length of the compensation elements 20 of the first group 25, measured in the direction of rotation, arranged in an aligned manner or aligned arrangement relative to one another.

The first set 25 comprises at least one magnetic interaction compensation element 27. The compensation element may be entirely a permanent magnet. Preferably, the magnetic compensation element 27 has a core which is formed by a permanent magnet, wherein the core is completely surrounded by a housing, in particular a housing made of plastic. The magnetic compensation element 27 can also be made at least partially of ferromagnetic material.

In one embodiment, the first group 25 has only a single magnetic compensation element 27, which is preferably arranged in the middle in the row of compensation elements 20 of the first group 25. As a result, the magnetic field or the magnetic force of the magnetic compensation element 27 can also act on the only magnetically interacting further compensation elements 20 in the first group 25 and maintain the remaining combination of the compensation elements 20 of the first group 25. Furthermore, a magnetic interaction with the holding device 26 is also ensured by this configuration. However, it can also be provided that the first group 25 has at least two magnetic compensation elements 27, which are then preferably arranged at the opposite ends of the rows of these compensation elements 20 of the first group 25, viewed in the azimuth direction. However, it can also be provided that, if at least two magnetic compensation elements 27 are present in the first group 25, the at least two magnetic compensation elements are arranged in an array such that, in particular, only the magnetically interacting compensation elements 20, the number of which remains constant, always follow the magnetic compensation elements 27 alternately.

Correspondingly, provision can be made in a second group 28 of compensation elements 20, which likewise has at least one magnetic compensation element 29.

As can be seen in the exemplary embodiment, a second holding device 30, which is independent of the first holding device 26, is assigned to the second group 28, in order to also form a corresponding magnetic holding force here. In the exemplary embodiment shown, the two

groups

25 and 28 and thus the holding

devices

26 and 30 are also arranged at a distance from one another in the circumferential direction about the axis a and are thus configured to be arranged opposite one another to some extent, which means with regard to the middle of the respective angles of orientation of the

groups

25 and 28 that they are offset from one another by 180 °. As can also be seen, the holding

devices

26 and 30 are located radially further inward than the compensating element 20, as viewed in the radial direction relative to the axis a.

The respective magnetic holding forces between the holding

device

26 or 30 and the compensating element 20 of the

group

25 or 28 held on the holding device in a magnetic interaction are predefined in a defined manner, wherein for this purpose the respective component is configured in a defined manner, which can be realized in terms of size and/or material.

Only the magnetically interactive compensating element 20 may be made of steel, for example, and thus not a permanent magnet. However, these further magnetically interactive compensating elements 20 are attracted by the compensating

elements

27 and 29, respectively, which contain at least a partial permanent magnet, so that the combination is held together and a magnetic interaction with the holding

device

26 or 30 occurs.

The positionally fixed couplings between the group 25 and the holding means 26 and between the group 28 and the holding means 30 are maintained in a defined manner for a long time until the washing drum 3 reaches a rotational speed greater than the reference rotational speed. The respective magnetic holding forces between the group 25 and the holding device 26 and between the group 28 and the holding device 30 are predefined in a defined manner and form a holding force threshold of this type to the extent that the centrifugal force acting on the compensating element 20 when the reference rotational speed is exceeded is greater than the respectively predefined magnetic holding force, so that the compensating element 20 is released from the holding device 26 on the one hand and the holding device 30 on the other hand.

In the case of a rotational speed of the laundry drum 3 which is greater than the reference rotational speed, the compensating element 20 moves relative to the holding

devices

26 and 30 in the cavity 19 and thus also relative to the housing 18.

This is illustrated in the diagram in fig. 4, in which the laundry drum 3 rotates at a rotational speed greater than the reference rotational speed. Here, it can be seen that the compensation elements 20 of the first group 25 and the compensation elements 20 of the second group 28 are in fact joined into a whole or a whole group 34 and are positioned in particular in the cavity 19 in order to compensate for the imbalance associated therewith due to the locally generated accumulation of the laundry 31. It is also possible to produce an arrangement of a plurality of groups of compensating elements, in which arrangement a resulting overall imbalance of the compensating elements occurs, which corresponds to the formed laundry imbalance and counteracts the laundry imbalance, i.e. compensates the laundry imbalance.

If the rotational speed of the laundry drum 3 then drops again and it falls below the differential rotational speed, such a state is automatically reached again as shown in fig. 3, and the

groups

25 and 28 are then magnetically coupled again individually to the associated holding

devices

26 and 30 and can no longer be moved relative thereto as follows in connection with this: they may come loose.

In a further advantageous embodiment of the imbalance compensation device 13, as shown in fig. 5, the housing 18 can have a radially inner wall 35, which is a bottom wall of the housing 18, which has recesses or recesses 36 and 37 in certain regions in the circumferential direction about the rotational axis a. The

recesses

36 and 37 can also be formed in a radially oriented side wall of the housing 18. The

recesses

36 and 37 extend in the direction of rotation about the axis of rotation a, in particular over a length which corresponds to the length of the

group

25 or 28 when all the compensating elements of such a

group

25 or 28 are aligned with one another. Preferably, the holding device 26 is arranged at the bottom of the recess 36 and the holding device 30 is arranged at the bottom of the recess 37. The

recesses

36 and 37 each have a stepped

transition

38, 39, 40, 41 to the deepened region of the wall 35. These

recesses

36 and 37 constitute separate elements which, in interaction with the non-magnetic

interaction compensation elements

32 and 33, at least contribute to the separation of the overall group 34 into

groups

25 and 28. Since the nonmagnetic

interaction compensation elements

32 and 33 are preferably lighter and/or larger in diameter than the further, in particular magnetically interacting, compensation elements of the overall group 34, the nonmagnetic interaction compensation elements acquire a smaller centrifugal force than these further compensation elements. As a result, when the rotational speed is reduced, the nonmagnetic interaction compensation element 32 and/or 33 sinks into the

recess

36 or 37 and then impinges on the end of the recess, in fig. 5 for example on the stepped transition 38 of the recess 36. Thereby initiating the separation of the integral group 34 and the decoupling of all the compensation elements of the integral group 34 azimuthally lined up with each other.

Fig. 6 shows the circuit of the holding device 26 in a schematic representation. The further holding devices 30 are preferably of identical design. The holding device 26 comprises an electromagnet 42, which in the present case is embodied as a resistor R. The electromagnet 42 may comprise an air-core coil. Alternatively, it can be provided that the electromagnet 42 has a coil with a corresponding core. When current I_EWhen passing through the electromagnet, a magnetic field is provided by electromagnet 42. The magnetic field produces a magnetic holding force between the electromagnet 42 or the holding device 26 and the

magnetic compensation element

20, 23, 27, 29. The magnetic force exerted by the electromagnet 42 on the

magnetic compensation element

20, 23, 27, 29 is adjusted by the geometry and the number of turns of the electromagnet 42. The magnetic force is further defined by the number of turns and the current I_EAnd (4) determining. For this purpose, the current I_ECan be actively regulated, for example by pulse width modulation.

Furthermore, the holding device 26 comprises an electrical energy store 43, which is shaped in the present case as a capacitor C in the electrical circuit. The voltage U can be provided via the electrical energy store 43_S. Furthermore, the holding device 26 comprises a receiving coil 44. Electrical energy may be coupled into the receive coil 44.

Furthermore, it can be seen in fig. 3 and 4 that the household appliance 1 furthermore comprises a first charging device 50. The first charging means 50 may, for example, be arranged in the washing liquid container 4. The first charging device 50 includesA transmission coil 51. The transmitting coil 51 may be loaded with an alternating current, thereby causing an alternating field. In the laundry drum 3, the laundry drum 3 or the holding device 26 can be arranged relative to the first charging device 31 in such a way that the transmitting coil 51 of the first charging device 31 is positioned relative to the receiving coil 44 of the holding device 26. Here, only one first charging device 50 is shown. In principle, it can also be provided that the household appliance 1 comprises a first charging device 50 for each holding

device

26 and 30. By means of the alternating field provided by the transmitting coil 51, a voltage U generated by induction can be generated in the receiving coil 44 of the holding device 26_L。

Furthermore, the household appliance 1 comprises a second charging device 52. The second charging device 52 furthermore comprises at least one magnetic element 53. In the present embodiment, the second charging device 52 includes three magnetic elements 53. The magnetic elements 53 may for example each comprise a permanent magnet. Alternatively, it can be provided that the magnetic element 53 comprises a coil, which can be operated with a direct current. A dc magnetic field is provided by the magnetic element 53. When the laundry drum 3 and thus the holding device 26 rotate, the receiving coil 44 moves relative to the magnetic element 53. This results in a voltage U being generated in the receiving coil 44 by induction_L. Thus, electrical energy can be transferred to the receiving coil 44 during the movement of the laundry drum 3.

As can be gathered from fig. 6, the holding device 26 furthermore has a rectifier 45, which is electrically connected to the receiving coil 44. The rectifier 45 comprises four diodes D for rectifying the voltage U generated by induction_LRectifies it and provides a rectified voltage U at the output of the rectifier 45_G. This rectified voltage U can then be used_GCharging the electrical energy storage 43.

Furthermore, the holding device 26 comprises a control device 46. The switch 47 can be controlled by means of a control device. The switch 47 can be controlled, for example, by means of the control device 46, if a reference rotational speed is reached. The switch 47 may be a semiconductor switch, such as a transistor. Thereby interrupting the current I flowing through the electromagnet 42_EThe flow of (c).

By inductionGenerated charging voltage U_LCan be used as a signal analysis with equivalent rotation speed. For this purpose, the control device 46 comprises a comparator 47. When the voltage U is generated by induction_LOr rectified voltage U_GIf a predetermined threshold value is exceeded, the switch 47 can be actuated by means of the control device 46. Here, the rectified voltage U_GIs highly dependent on the rotational speed, since the voltage supplied by the second charging device 52 rises as the rotational speed increases.

The release of the

magnetic compensation weights

20, 23, 27, 29 from the holding

devices

26, 30 can be effected either actively or passively. Passive release is to be understood to mean that the magnetic holding force provided by the electromagnet 42 is designed such that the compensating

weight body

20, 23, 27, 29 automatically releases from the holding

device

26, 30 due to centrifugal force when the reference rotational speed is reached. For this purpose, the discharge characteristics of the electrical energy store 43 can be utilized. For this purpose, fig. 7 shows a graph 49 which depicts the voltage U of the electrical energy store 43_SAs a function of time t. The voltage U of the electrical energy store 43 is then present_SShown standardized. Here, it can be seen that the voltage U_SDecreasing exponentially with time t.

Furthermore, the release of the

magnetic compensation elements

20, 23, 27, 29 can be performed actively. The switch 47 can be controlled by means of the control device 46. The control of the switch 47 is carried out in particular as a function of the rotational speed of the laundry drum 3. The compensating

elements

20, 23, 27, 29 can therefore be held in the subcritical and critical rotational speed range and released in the supercritical rotational speed range.

List of reference numerals

1 household appliance

2 housing of a household appliance

3 washing drum

4 container for washing liquid

5 inside the laundry drum

6 door

7 hollow column-shaped outer cover

8 charging opening

9 rear wall

10 Star shaped support

11 axle

12 inside

13, 14 unbalance compensator

15 synchronizing member

16 front region

17 rear area

18 housing of a first unbalance compensation device

19 cavity

20 compensating element

21 housing of a second unbalance compensation device

22 cavity

23 compensating element

24 receiving part

25 first group

26 holding device

27 magnetic compensation elements of a first group

28 second group

29 magnetic compensation elements of the second group

30 holding device

31 washing article

32 non-magnetic compensation element

33 non-magnetic compensating element

34 integral group

35 wall

36 concave part

37 recess

38 transition part

39 transition part

40 transition part

41 transition part

42 electromagnet

43 electric energy accumulator

44 receiving coil

45 rectifier

46 control device

47 switch

48 comparator

49 graph

50 charging device

51 transmitting coil

53 charging device

54 magnetic element

Axis A

C capacitor

D diode

I_EElectric current

R resistance

time t

U_GRectified voltage

U_LBy induced voltage

U_SVoltage of

Claims

1. Household appliance (1) for caring for laundry (31), having at least one laundry drum (3) for receiving the laundry (31) and at least one unbalance compensation device (13, 14) which is arranged on the laundry drum (3) and which has a housing (18, 21) in which a plurality of compensation elements (20, 23, 27, 29, 32, 33) are movably contained, characterized in that at least some of the compensation elements (20, 23, 27, 29) are magnetic, i.e. comprise at least permanent-magnetic and/or ferromagnetic compensation elements, and in that the unbalance compensation device (13, 14) comprises at least one holding device (26, 30) which is rotationally coupled to the laundry drum (3), wherein the holding device (26, 30) comprises an electromagnet (42), the electromagnet is designed to generate a magnetic field which causes a magnetic retaining force between the electromagnet (42) and the magnetic compensation element (20, 23, 27, 29), wherein the retaining device (26, 30) has an electrical energy store (43) for supplying the electromagnet (42) with electrical energy.

2. Household appliance (1) according to claim 1, characterized in that the magnetic compensation element (20, 23, 27, 29) and the electromagnet (42) are designed with a magnetic holding force relative to one another, so that the decoupling of the compensation element (20, 23, 27, 29) from the holding device (26, 30) takes place only at a predefined reference rotational speed of the laundry drum (3).

3. Household appliance (1) according to claim 1 or 2, characterized in that the holding device (26, 30) has a control device (46) which is designed to determine the rotational speed of the laundry drum (3) and to control the current (I) flowing through the electromagnet (42) as a function of the determined rotational speed of the laundry drum (3)_E)。

4. Household appliance (1) according to claim 1 or 2, characterized in that the electrical energy store (43) has a predetermined discharge characteristic describing the voltage (U) supplied by the electrical energy store (43)_S) As a function of time (t).

5. Household appliance (1) according to claim 1 or 2, characterized in that the electrical energy store (43) is designed to supply at least one further electrical component of the household appliance (1) with electrical energy.

6. Household appliance (1) according to claim 1 or 2, characterized in that the holding device (26, 30) comprises a receiving coil (44) into which electrical energy can be coupled and which is electrically connected with the electrical energy store (43).

7. Household appliance (1) according to claim 6, characterized in that the household appliance (1) comprises a first charging device (50), wherein the first charging device (50) has a transmitting coil (51) for inductively transferring electrical energy onto a receiving coil (44) of the holding device (26, 30).

8. Household appliance (1) according to claim 7, characterized in that the transmission coil (51) is designed to inductively transfer electrical energy onto the receiving coil (44) if the laundry drum (3) is in a stationary state and the transmission coil (51) is arranged in a predetermined position with respect to the receiving coil (44).

9. Household appliance (1) according to claim 6, characterized in that the household appliance (1) has a second charging device (52), wherein the second charging device (52) has at least one magnetic element (53) with respect to which the laundry drum (3) is rotatable and which is designed for generating a direct-current magnetic field.

10. Household appliance (1) according to claim 9, characterized in that the at least one magnetic element (53) is configured such that upon movement of the laundry drum (3) relative to the second charging device (52), a voltage (U) is induced in the receiving coil (44) due to the direct-current magnetic field_L)。

11. Household appliance (1) according to claim 10, characterized in that the control device (46) of the holding device (26, 30) is designed to detect the voltage (U) induced in the receiving coil (44)_L) And in dependence on the detected voltage (U)_L) The rotational speed of the laundry drum (3) is determined.

12. The household appliance (1) according to any of claims 1-2, 7-11, wherein the electromagnet (42) comprises an air coil.

13. The household appliance (1) according to any of claims 1-2, 7-11, wherein the electromagnet (42) comprises a coil and a core arranged at least partially inside the coil.

14. Household appliance (1) according to claim 5, characterized in that said further electrical component is an electrical component rotating together with said laundry drum (3).

15. Method for operating a household appliance (1) for caring for laundry (31), having at least one laundry drum (3) for receiving the laundry (31) and at least one unbalance compensation device (13, 14) which is arranged on the laundry drum (3) and which has a housing (18, 21) in which a plurality of compensation elements (20, 23, 27, 29, 32, 33) are movably contained, characterized in that at least some of the compensation elements (20, 23, 27, 29) are magnetic, i.e. comprise at least permanent-magnetic and/or ferromagnetic compensation elements, and in that the unbalance compensation device (13, 14) comprises at least one retaining device (26, 30) which is rotationally coupled to the laundry drum (3), the holding device has an electromagnet (42), wherein a magnetic field is generated by means of the electromagnet (42), said magnetic field causing a magnetic holding force between the electromagnet (42) and the magnetic compensation element (20, 23, 27, 29), wherein the holding device (26, 30) has an electrical energy store (43) for supplying the electromagnet (42) with electrical energy.