Household appliance, in particular water-bearing household appliance

Abstract

The invention relates to a household appliance, in particular a water-bearing household appliance, with a housing (3) providing a compartment (4) and having a loading opening (5) for accessing the compartment (4), with a door (6) rotatably mounted about a pivot axis for closing the loading opening (5), with a motor unit (13) and an intermediate member (11) driven by the motor unit (13), and with a power transmission means (9) arranged between the intermediate member (11) and the door (6), so that the door (6) can be moved from an open position to a closed position closing the loading opening (5) by means of the motor unit (13), and with a coupling device (14) arranged between the motor unit (13) and the intermediate member (11), which has a coupling (15) that is switchable and can be moved from a disengaged position to a engaged position and vice versa.wherein the coupling (15) is an electrically switchable coupling.

Description

[0001] The invention relates to a household appliance, in particular a water-conducting household appliance, such as a dishwasher, with an appliance housing providing an appliance compartment, which has a loading opening for access to the appliance compartment, with an appliance door mounted so as to be rotatable about a pivot axis for closing the loading opening, with a motor unit, with an intermediate member drivable by the motor unit, and with a power transmission means arranged between the intermediate member and the appliance door, so that the appliance door can be moved by means of the motor unit from an open position into a closed position closing the loading opening, and with a coupling device arranged between the motor unit and the intermediate member, which has a coupling which is designed to be switchable and can be moved from an uncoupled position into a coupled position and vice versa.

[0002] Household appliances in general, and water-using household appliances in particular, are well known in the art, so a separate written reference is not required here. Reference is therefore made, by way of example, to EP 3 875 017 A1, which discloses a generic household appliance in the form of a dishwasher.

[0003] A household appliance of this type has a housing that provides a compartment. For user access to the compartment, the housing has a loading opening that can be closed by a door. The door is mounted on the housing and can pivot about a pivot axis.

[0004] To simplify at least one pivoting movement of the appliance door from an open position to a closed position closing the loading opening, EP 3 875 017 A1 discloses the use of a motor unit operatively connected to the appliance door. The motor unit allows the appliance door to be moved from an open position to a closed position closing the loading opening after prior activation by the user, without further manual intervention by the user.

[0005] The household appliance known from EP 3 875 017 A1 has, in a conventional manner, a spring mechanism that serves to balance the weight of the appliance door. This spring mechanism comprises a spring element on the one hand and a force transmission means on the other.

[0006] The spring element is designed as a helical spring and is hinged to the appliance housing at one end. At the other end, the spring element is arranged on the force transmission means, which in the case of EP 3 875 017 A1 is a toothed belt. This toothed belt, with its end facing away from the spring element, is connected to the appliance door in a force-transmitting manner. For this purpose, the appliance door has a lever on which the toothed belt is arranged at one end. Two deflection pulleys are also provided, around which the toothed belt is guided.

[0007] When the appliance door is opened, the toothed belt exerts tension on the spring element. As a result, it expands. As a result, the weight of the appliance door is absorbed, allowing the appliance door to remain half-open without further manual intervention and preventing it from opening uncontrollably, for example, due to incorrect operation. When the appliance door is fully open, the spring element is at its maximum tension, allowing it to retract when the door is closed, thus supporting the closing movement of the appliance door.

[0008] The motor unit provided for the motor-assisted transfer of the appliance door from an open position to a closed position, as described in EP 3 875 017 A1, drives one of the two deflection pulleys around which the toothed belt is wound. This deflection pulley serves as an intermediate link, transmitting the torque generated by the motor unit during intended use to the toothed belt. The toothed belt and the deflection pulley, which serves as an intermediate link, interact in a form-fitting manner, which advantageously enables slip-free power transmission to the toothed belt, which serves as the power transmission means.

[0009] To ensure a force decoupling between the intermediate link and the motor unit, particularly when the user manually moves the appliance door into an open position, a coupling device is arranged between the motor unit and the intermediate link. This coupling device has a switchable clutch that can be moved from an uncoupled position to a coupled position and vice versa. The coupling device ensures a force coupling between the motor unit and the intermediate link when a motor-assisted transfer of the appliance door from an open position to a closed position closing the loading opening is to take place. Otherwise, the clutch of the coupling device is in its uncoupled position, which allows the user to manually pivot the appliance door.

[0010] According to the design known from EP 3 875 017 A1, the clutch of the clutch device is a mechanical clutch that, when the motor unit is in operation, automatically shifts from the uncoupled position to the coupled position. For this purpose, the known clutch has a rotating part and pivotally mounted clamping pieces that interact with a clutch housing.

[0011] To prevent an unwanted overload when the clutch is in the engaged position, the clutch device known from EP 3 875 017 A1 has a second clutch. This second clutch is designed as an overload clutch and serves, in particular for safety reasons, as a trap protection device and prevents the door from closing if the door is blocked. This second clutch can be designed, for example, as a slip clutch, whereby in the event of an overload, it prevents power transmission due to slipping despite the first clutch being engaged.

[0012] Although the design described above and known from EP 3 875 017 A1 has proven itself in everyday practical use, there is still room for improvement. Particularly with regard to the coupling device, simplified handling is desired. Therefore, TaskThe invention aims to further develop the construction known from EP 3 875 017 A1 in such a way that simplified handling is possible while at the same time expanding the range of applications.

[0013] To Solution To achieve this object, the invention proposes a household appliance of the type mentioned at the outset, which is characterized in that the clutch is an electrically switchable clutch.

[0014] In contrast to the previously known prior art according to EP 3 875 017 A1, the clutch of the clutch device according to the invention is not a mechanically switching clutch, but an electrically switching clutch.

[0015] The particular advantage of the purely mechanically switching clutch previously known from EP 3 875 017 A1 is its long-lasting robustness, even under humid conditions, such as those that can occur, for example, in the case of a household appliance designed as a dishwasher. It has now been shown that such reliable robustness can also be achieved with an electrically switchable clutch. An electrically switchable clutch offers the additional advantage that it not only enables motorized closing of the appliance door, but also motorized opening of the appliance door. In contrast to the design according to EP 3 875 017 A1, it thus enables fully motorized operation of the appliance door, i.e., motorized movement of the appliance door from an open position to a closed position and in the reverse direction.The use of an electrically switchable clutch according to the invention thus increases the range of applications, whereby a user of the household appliance is now able to receive motor support not only during a closing movement of the appliance door, but also during an opening movement of the appliance door.

[0016] Another advantage of the design according to the invention is that a second clutch serving as an overload clutch is no longer required. The clutch device according to the invention therefore has only one clutch, namely an electrically switchable clutch, and not two clutches, as is provided for in the prior art according to EP 3 875 017 A1. This is because the electrically switchable clutch provided according to the invention can advantageously also enable slipping in the event of an overload, thereby serving as anti-pinch protection and preventing the door from closing if it becomes blocked. As a result, the design according to the invention is simpler than the construction known from the prior art and is also more cost-effective to implement.

[0017] Furthermore, the electrically switchable clutch provided according to the invention offers a much faster response time than the previously known mechanical clutch. In particular, the clutch can be engaged and disengaged much more quickly, which offers significant advantages, for example, in the event of a jammed door drive system. Depending on the design of the clutch according to the invention, releasing the clutch, i.e., disengaging it, can be achieved by simply switching on or off the voltage applied to the electrically switchable clutch, which leads to immediate clutch actuation. Such fast response times cannot be achieved with purely mechanical clutches.

[0018] According to a further feature of the invention, the coupling comprises a first coupling part that is arranged in a rotationally fixed yet movable manner on a shaft on the motor unit side. This coupling part is connected to the motor unit in a force-transmitting manner and, during normal operation, enables torque transmission from the motor unit to the intermediate member interacting with the appliance door. This enables reliable power transmission from the motor unit to the appliance door during operation.

[0019] For the purpose of intended torque transmission, the first coupling part is arranged in a rotationally fixed manner on the motor unit-side shaft. The arrangement of the first coupling part on the motor unit-side shaft is further designed in such a way that axial displacement between the first coupling part and the motor unit-side shaft is possible. This arrangement of the first coupling part, which can be moved longitudinally along the motor unit-side shaft, enables the clutch to be engaged. The first coupling part interacts with a second coupling part, and both coupling parts are operatively engaged when the clutch is engaged. Otherwise, the two coupling parts are separated from one another in their power transmission, so that torque transmission from the motor unit to the appliance door is interrupted. The clutch is therefore engaged by axial displacement of the first coupling part.In the engaged position, the first clutch part rests against the second clutch part. Otherwise, the first clutch part is axially spaced from the second clutch part, in which case the clutch is decoupled.

[0020] According to a further feature of the invention, the first coupling part is supported by a hub body fixedly arranged on the shaft. The first coupling part is thus arranged on the shaft with the hub body interposed, with the hub body being fixed to the shaft. When used as intended, torque can thus be transmitted from the shaft to the hub body and from there to the first coupling part.

[0021] According to a further feature of the invention, the first coupling part is arranged on the hub body so that it can be displaced axially in the longitudinal direction of the shaft. This displaceable arrangement of the first coupling part on the hub body realizes the previously described relative displaceability of the first coupling part to the shaft in the longitudinal direction of the shaft. The result of this design is that, with the interposition of the hub body, the axially displaceable arrangement of the first coupling part in relation to the shaft is achieved, while the torsion-proof arrangement of the first coupling part on the hub body simultaneously ensures that torque is transmitted to the coupling part during its intended use.

[0022] According to a further feature of the invention, an electrically switchable actuator acting in the longitudinal direction of the shaft is arranged between the first coupling part and the hub body.

[0023] This actuator provided according to the invention enables electrically actuated switching of the clutch. This is because the actuator is designed to be electrically switchable and, when energized, causes an axial displacement of the first clutch part in relation to the hub body. For this purpose, the actuator is arranged between the first clutch part and the hub body, acting in the longitudinal direction of the shaft. The actuator is supported on the hub body as an abutment, so that when energized the actuator, force is transmitted to the clutch part, thereby causing an axial displacement of the clutch part in relation to the hub body. In a very simple manner, the clutch can be switched by energizing the actuator; depending on the design of the actuator, energization leads either to coupling or decoupling of the clutch according to the invention.

[0024] According to a further feature of the invention, the actuator comprises a spring element that can be energized. The spring element can be designed either as a compression spring or as a tension spring. When energized, the force of the spring element is reversed, so that, depending on the design, the first coupling part is either repelled from the hub body or attracted to the hub body.

[0025] According to a particularly preferred embodiment of the invention, the spring body is formed from a shape memory alloy.

[0026] Shape memory alloys assume two different phases depending on temperature. A possible shape transformation of the spring body formed from a shape memory alloy is therefore based on a temperature-dependent lattice transformation into one of these two phases, also called crystal structure phases. There is generally a high-temperature phase called austenite and a low-temperature phase called martensite. If the shape memory alloy is mechanically deformed in the low-temperature phase, it can then be returned to its original shape by heating. The shape memory alloy is ideally heated directly by applying current to the spring body formed from the shape memory alloy or indirectly via a separate heat source.

[0027] Preferably, the spring body made of a shape memory alloy provided according to the invention is held in a compressed position when the clutch is disengaged. If current is then applied to the spring body, it expands, causing an axial displacement of the first clutch part, thus engaging the clutch. As soon as the current is removed from the spring body, it can be returned to its compressed position, resulting in an axial retraction of the clutch part, thus disengaging the clutch.

[0028] According to a further feature of the invention, a tension or compression means acting in the longitudinal direction of the shaft is arranged between the first coupling part and the hub body. Such a tension or compression means can preferably be a spring, for example a helical spring. This spring counteracts the spring body serving as the actuator and, depending on the design, holds it in a compressed position either when energized or de-energized. Therefore, the spring is also designed either as a tension means or as a compression means.

[0029] According to a preferred embodiment, the spring body made of a shape memory alloy expands when energized. Accordingly, tension means interact with the spring body, holding it in a compressed position when energized. When energized, the spring body expands in the axial direction with a force that exceeds the force of the tension springs. This results in an axial displacement of the first coupling part in relation to the hub body. If the energization of the spring body is now interrupted, the spring body cools, causing it to return to its original shape, which is achieved by the application of the tension means. When energized, the spring body is thus moved back into the compressed position by the tension means, in which the first coupling part is separated from the second coupling part, and the coupling is thus uncoupled.

[0030] According to a further feature of the invention, the coupling comprises a second coupling part that interacts with the first coupling part and is arranged on the intermediate member in a rotationally fixed manner. When used as intended, a direct transmission of force or torque can thus take place from the second coupling part to the intermediate member. Since the intermediate member, in turn, interacts with the force transmission means, a torque generated by the motor unit can be transmitted to the appliance door. Preferably, the second coupling part and the intermediate member are formed as a single-piece component, which advantageously results in an overall compact design.

[0031] According to a further feature of the invention, the clutch parts are provided with friction linings on their mutually facing end faces, which interact in a force-locking and / or positive-locking manner. This force-locking and / or positive-locking interaction provides force or torque transmission in the intended clutch condition. The interaction of the friction linings is preferably designed such that, in the event of an overload, a relative rotational movement of the two clutch parts relative to each other is possible for safety reasons, thus providing anti-pinch protection.

[0032] According to a further feature of the invention, the force transmission means and the intermediate link engage with each other in a force-locking and / or positive-locking manner. The force transmission means can thus be, for example, a toothed belt, and the intermediate link a cooperating gear. Alternatively, the force transmission means is designed as a cable, in which case the intermediate link is designed, for example, as a cable drum around which the cable is wound. A lever arrangement, a chain, or a so-called ball chain are also possible as the force transmission means.

[0033] According to one exemplary embodiment, the household appliance can be equipped in a manner known per se with a spring mechanism which serves to compensate for the weight of the appliance door. The spring mechanism comprises a spring element and a force transmission means arranged between the spring element and the appliance door, which force transmission means can (likewise) be designed, for example, as a cable, toothed belt, chain, or ball chain. According to a first embodiment of this exemplary embodiment, the household appliance has a first force transmission means which serves to close and / or open the appliance door and is arranged, as described above, between the intermediate member and the appliance door, and in addition thereto a separate second force transmission means which is assigned to the spring mechanism which serves to compensate for the weight of the appliance door and which is arranged between the spring element and the appliance door.According to an alternative second embodiment of this exemplary embodiment, the force transmission means, which serves to close and / or open the appliance door and, as previously described, is arranged between the intermediate member and the appliance door, is realized by a section of a force transmission means arranged between the spring element and the appliance door, which is associated with the spring mechanism that serves to balance the weight of the appliance door. In other words, in this embodiment, (only) one force transmission means is present, arranged between the spring element and the appliance door, which is operatively connected to the intermediate member driven by the motor unit. This allows for a more compact and simpler design.

[0034] Further features and advantages of the invention will become apparent from the following description with reference to the figures. Fig. 1 shows a purely schematic representation of a household appliance according to the invention; Fig. 2 shows a schematic perspective view of a detail of a coupling device according to the invention; Fig. 3 shows a schematic representation of a coupling according to the invention in the uncoupled position and Fig. 4 shows a schematic representation of the coupling according to Fig. 3 in coupled position.

[0035] Fig. 1 shows a purely schematic representation of a household appliance according to the invention in the form of a dishwasher 1.

[0036] The dishwasher 1 has an outer casing 2 that houses an appliance housing 3. The appliance housing 3, in turn, provides an appliance compartment 4, which, when used as intended, serves to accommodate items to be cleaned. The appliance housing 3 has a loading opening 5 for access to the appliance compartment 4.

[0037] The dishwasher 1 further comprises an appliance door 6 mounted for rotation about a pivot axis, which serves to close the loading opening 5. The appliance door 6 can be moved from a closed position, closing the loading opening 5, to an open position, and vice versa. Fig. 1 shows the appliance door 6 in an open position in which the loading opening 5 is partially open.

[0038] As the detail display after Fig. 2 As can be seen, the appliance door 6 has a lever 10 arranged on it near the pivot axis. One such lever 10 is provided on each side of the appliance door 6.

[0039] On one end of each lever 10, a toothed belt serving as a force transmission means 9' is arranged, which is guided around a first deflection pulley designed as a gear and serving as an intermediate link 11.

[0040] Optionally, the power transmission device 9.9` can be used as in Fig. 2 As shown, it can also be guided around a second deflection roller 12 and arranged at the other end on a spring element 8 stationary relative to the device housing 3. This spring element 8, together with the toothed belt 9 serving as the power transmission means, forms the spring mechanism 7.

[0041] When the appliance door 6 is opened, the levers 10 are each

[0042] Force transmission means 9, 9' are subjected to tensile stress, which leads to tensioning of the spring element 8 arranged at the other end of the respective force transmission means 9. This provides weight compensation with respect to the appliance door 6, which in particular prevents an uncontrolled downward pivoting of the appliance door 6.

[0043] The force stored in the spring elements 8 is released again when the appliance door 6 is moved back into the closed position, which enables simplified closing of the appliance door 6.

[0044] The dishwasher 1 further comprises a motor unit 13. This motor unit 13 is operatively connected to the appliance door 6 and allows the appliance door 6 to be pivoted by a motor.

[0045] When the motor unit 13 is in operation, it drives the gear wheel serving as an intermediate link 11 via a coupling device 14, which cooperates with the toothed belt, i.e. the power transmission means 9, 9'. A motor-driven rotation of the gear wheel serving as an intermediate link 11 leads to the Fig. 2 The embodiment shown therefore leads to a force loading or unloading of the spring element 8, depending on the direction of rotation of the motor unit 13.

[0046] As can be seen from a summary of the further Figures 3 and 4 According to the invention, the coupling device 14 has an electrically switchable coupling 15.

[0047] As can be seen from the illustration Fig. 3The motor unit 13 has a motor 24 and a gear 23 interacting with it. The motor unit 13 is operatively connected to a shaft 20, which can rotate depending on the direction of rotation of the motor 24.

[0048] With the interposition of a bearing 26, the shaft 20 carries the intermediate member 11, which in the illustrated embodiment is designed as a gear, wherein the intermediate member 11 can rotate in relation to the shaft 20 due to the interposition of the bearing 26.

[0049] The coupling device 14 has an electrically switchable coupling 15 which has two coupling parts, namely a first coupling part 16 on the one hand and a second coupling part 17 on the other hand.

[0050] According to the Fig. 3In the embodiment shown, the first coupling part 16 is arranged on the motor-unit-side shaft 20 in a rotationally fixed but axially displaceable manner. This is achieved by a hub body 18, which is fixedly arranged on the shaft 20 and supports the first coupling part 16 axially displaceably in the longitudinal direction 19 of the shaft 20. A toothing 32, which will be explained in more detail below, ensures a rotationally fixed arrangement of the first coupling part 16 on the hub body 18.

[0051] The shaft 20 is arranged rotatably relative to a bearing holder 28 with the hub body 18 interposed therebetween, with a bearing 25 serving as rotatable support. In the illustrated embodiment, a key 27 is provided for the stationary arrangement of the hub body 28 on the shaft 20.

[0052] As can be seen from the illustration Fig. 3Furthermore, the hub body 18 has a plate 29 and an annular body 30 formed integrally therewith. The annular body 30 engages with its end face opposite the plate 29 in a correspondingly formed groove 31 of the first coupling part 16. This interaction of the annular body 30 on the one hand and the first coupling part 16 on the other hand enables an axial displacement of the first coupling part 16 in the longitudinal direction 19, in relation to the hub body 18 and thus also to the shaft 20. The groove 31 and the annular body 30 provide a toothing 32 which engages with one another in the finally assembled state, so that the first coupling part 16 is connected to the hub body 18 in a rotationally fixed manner. In the finally assembled state, a torque generated by the motor unit 13 can therefore be transmitted to the first coupling part 16 via the shaft 20 and the hub body 18.At the same time, due to the above-described design, the first coupling part 16 is designed to be axially displaceable relative to the hub body 16 in the longitudinal direction 19 of the shaft 20.

[0053] Between the first coupling part 16 and the hub body 18, an actuator 21 acting in the longitudinal direction 19 of the shaft 20 is arranged, which is designed to be electrically switchable. Fig. 3 In the embodiment shown, the actuator 21 is an energizable spring body made of a shape memory alloy. The shape memory alloy is, for example, an alloy containing nickel, titanium, and nitinol.

[0054] Shape memory alloys can be transformed into two different phases depending on temperature. This phase transition results in a shape transformation based on the temperature-dependent lattice transformation into one of the two phases. Typically, the so-called high-temperature phase and the so-called low-temperature phase are provided. If the shape memory alloy is mechanically deformed in the low-temperature phase, it can then be returned to its original shape by heating. The shape memory alloy can be heated directly via current or indirectly via a separate heat source.

[0055] In the illustrated embodiment, the electrically switchable actuator 21 is formed as a spring body made of a spring wire, wherein the spring wire is formed from a shape memory alloy in the manner already described. Heating of the spring body preferably takes place by applying a voltage to the wire of the spring body. Consequently, energizing or de-energizing the spring body allows it to expand or contract in the longitudinal direction 19 of the shaft 20. The spring body serving as actuator 21 is supported on the hub body 18 in the manner of an abutment, so that actuation of the actuator 21 leads to an axial displacement in the longitudinal direction 19 of the coupling part 16.

[0056] Furthermore, tension or compression means 22 acting in the longitudinal direction 19 of the shaft 20 are arranged between the first coupling part 16 and the hub body 18. In the illustrated embodiment, these are springs. Depending on the design of the actuator 21, the springs are either tension springs or compression springs.

[0057] According to the embodiment shown, the actuator 21 is designed as a compression spring deflected in its original shape, which is mechanically held in compressed deflection at room temperature by one or more tension springs, as in Fig. 3 The tension springs therefore serve as return elements for the actuator 21.

[0058] If, in the intended use, a voltage is applied to the wire of the spring body serving as the actuator 21, this results in heating of the spring body, as a result of which the shape memory alloy from which the wire of the spring body is formed is transferred from its low-temperature phase to its high-temperature phase. This phase transition causes the spring body to return to its original shape as a deflected compression spring, as a result of which the first coupling part 16 moves axially in the longitudinal direction 19 towards the second coupling part 17, ie with reference to the plane of the drawing Fig. 3 to the left. As a result of this movement of the first coupling part 16, the two coupling parts 16 and 17 are coupled, as shown in Fig. 4shown. In this coupled position, the two friction linings 33 and 34 of the two clutch parts 16 and 17 rest against one another, so that a torque provided by the motor unit 13 can be transmitted from the shaft 20 via the first clutch part 16 to the second clutch part 17 and from there to the intermediate member 11.

[0059] The two coupling parts 16 and 17 are easily disconnected by switching off the power supply, which causes the spring body serving as the actuator 21 to cool down. As a result of this cooling, the spring body is no longer deflected in the axial direction, so that the springs serving as the traction means 22 pull the first coupling part 16 back axially, ie with respect to the plane of the drawing Fig. 3in the axial direction 19 to the right. This decouples the two coupling parts 16 and 17 from each other, so that the transmission of force or torque from the motor unit 13 to the intermediate link 11 is interrupted.

[0060] As can be seen from the above illustration, the clutch device 14 according to the invention can be switched by simply energizing or de-energizing the electrically switchable actuator 21. According to the embodiment shown, the clutch 15 provided by the clutch device 14 is decoupled when not energized, ie the two clutch parts 16 and 17 are separated from each other, as shown in Fig. 3 As soon as the actuator 21 is energized, it expands in the axial direction 19, whereby it is supported on the hub body 18, which leads to an axial displacement of the coupling part 16 in the longitudinal direction 19 with respect to the plane of the drawing according to Fig. 3to the left. As a result of this displacement movement, the first clutch part 16 comes into contact with the second clutch part 17, thus engaging the clutch 15. In this engaged position, the friction linings 33 and 34 provided by the two clutch parts 16 and 17 engage with each other in a force-locking and / or form-locking manner, which enables torque to be transmitted from the motor unit 13 via the shaft 20, the first clutch part 16, and the second clutch part 17 to the intermediate member 11.

[0061] The advantage of this coupling design is that it provides a fast response time, meaning it can be transferred from a coupled position to a decoupled position relatively quickly. A further advantage is that, depending on the direction of rotation of the motor 24, power transmission is possible in both directions of motor rotation. Thus, a device door 6 operatively connected to the motor unit 13 can be pivoted with motor support both from an open position to a closed position and vice versa. Reference symbol

[0062] 1 Dishwasher 2 Outer casing 3 Appliance housing 4 Appliance compartment 5 Loading opening 6 Appliance door 7 Spring mechanism 8 Spring element 9 Power transmission means 10 Lever 11 Intermediate link 12 Deflection pulley 13 Motor unit 14 Coupling device 15 Coupling 16 First coupling part 17 Second coupling part 18 Hub body 19 Longitudinal direction 20 Shaft 21 Actuator 22 Tension / compression means 23 Gearbox 24 Motor 25 Bearing 26 Bearing 27 Key 28 Bearing holder 29 Plate 30 Annular body 31 Groove 32 Toothing 33 Friction lining 34 Friction lining

Claims

1. A household appliance, in particular a water-conducting household appliance, comprising an appliance housing (3) providing an appliance compartment (4) and having a loading opening (5) for access to the appliance compartment (4), an appliance door (6) rotatably mounted about a pivot axis for closing the loading opening (5), a motor unit (13) and an intermediate member (11) drivable by the motor unit (13), as well as a power transmission means (9, 9') arranged between the intermediate member (11) and the appliance door (6), such that the appliance door (6) can be moved by means of the motor unit (13) from an open position into a closed position closing the loading opening (5), and a coupling device (14) arranged between the motor unit (13) and the intermediate member (11), which has a switchable coupling (15) and can be moved from a decoupled position into a coupled position and vice versa, characterized in thatthe clutch (15) is an electrically switchable clutch.

2. Household appliance according to claim 1, characterized in that the coupling (15) has a first coupling part (16) which is arranged in a rotationally fixed but nevertheless displaceable manner on a shaft (20) on the motor unit side.

3. Household appliance according to claim 2, characterized in that the first coupling part (16) is carried by a hub body (18) arranged stationary on the shaft (20).

4. Household appliance according to claim 3, characterized in that the first coupling part (16) is arranged on the hub body (18) so as to be axially displaceable in the longitudinal direction (19) of the shaft (20).

5. Household appliance according to claim 3 or 4, characterized in that an electrically switchable actuator (21) acting in the longitudinal direction (19) of the shaft (20) is arranged between the first coupling part (16) and the hub body (18).

6. Household appliance according to claim 5, characterized in thatthe actuator (21) has an energizable spring body.

7. Household appliance according to claim 6, characterized in that the spring body is made of a shape memory alloy.

8. Household appliance according to one of the preceding claims 5 to 7, characterized in that a pulling or pushing means (22) acting in the longitudinal direction (19) of the shaft (20) is arranged between the first coupling part (16) and the hub body (18).

9. Household appliance according to claim 8, characterized in that the tension or compression means (22) is a spring, preferably a helical spring.

10. Household appliance according to one of the preceding claims 2 to 9, characterized in that the coupling (15) has a second coupling part (17) which interacts with the first coupling part (16) and is arranged in a rotationally fixed manner on the intermediate member (11).

11. Household appliance according to claim 10, characterized in thatthe clutch parts (16, 17) carry friction linings (33, 34) on their mutually facing end faces, which interact in a force-locking and / or form-locking manner.

12. Household appliance according to one of the preceding claims, characterized in that the force transmission means (9, 9') and the intermediate member (11) engage with each other in a force-locking and / or form-locking manner.

13. Household appliance according to one of the preceding claims, characterized in that the force transmission means (9, 9`) is a lever arrangement, a rope, a toothed belt, a chain or a ball chain.

14. Household appliance according to one of the preceding claims, characterized by a spring mechanism (7) which serves to balance the weight of the appliance door (6) and has a spring element (8) and a force transmission means (9) arranged between the spring element (8) and the appliance door (6)

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